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+The Project Gutenberg EBook of A History of the Growth of the Steam-Engine, by 
+Robert H. Thurston
+
+This eBook is for the use of anyone anywhere at no cost and with
+almost no restrictions whatsoever.  You may copy it, give it away or
+re-use it under the terms of the Project Gutenberg License included
+with this eBook or online at www.gutenberg.org
+
+
+Title: A History of the Growth of the Steam-Engine
+
+Author: Robert H. Thurston
+
+Release Date: April 19, 2011 [EBook #35916]
+
+Language: English
+
+Character set encoding: ISO-8859-1
+
+*** START OF THIS PROJECT GUTENBERG EBOOK STEAM ***
+
+
+
+
+Produced by Chris Curnow, Harry Lamé and the Online
+Distributed Proofreading Team at http://www.pgdp.net (This
+file was produced from images generously made available
+by The Internet Archive)
+
+
+
+
+
+
+
+
+
+  +-------------------------------------------------------------------+
+  |                                                                   |
+  |                       TRANSCRIBER'S NOTES:                        |
+  |                                                                   |
+  |                                                                   |
+  |Formatting and coding information:                                 |
+  |  - Text in italics is marked with underscores as in _text_.       |
+  |  - Bold-face text is marked =text=.                               |
+  |  - Superscript x and subscript x are represented as ^{x} and _{x},|
+  |    respectively.                                                  |
+  |  - sqrt(x) represents the square root of x.                       |
+  |  - [oe] and [OE] represent the oe-ligatures.                      |
+  |  - Greek letters are written between square brackets, as in [tau] |
+  |    or [theta].                                                    |
+  |  - Overlined 1 is represented as [=1].                            |
+  |  - [<] represents a 'rotated [Delta]'.                            |
+  |                                                                   |
+  |General remarks:                                                   |
+  |  - Footnotes have been moved to directly below the paragraph they |
+  |    refer to.                                                      |
+  |  - In-line multiple line formulas have been changed to in-line    |
+  |    single-line formulas, with brackets added when needed.         |
+  |  - The Table of Contents has been corrected to conform to the text|
+  |    rather than to the original Table of Contents.                 |
+  |  - The table on operating costs of trains gives 'Other expenses   |
+  |    per square mile.' This has been changed to 'Per mile' the same |
+  |    as the other expenses.                                         |
+  |  - The table on dimensions of farm and road locomotives gives the |
+  |    diameter of the boiler shell as 30 feet, which seems unlikely. |
+  |  - Feet are sometimes used as unit of area, both knots and knots  |
+  |    per hour as unit of speed.                                     |
+  |                                                                   |
+  |Changes in text:                                                   |
+  |  - Reference letters in the text have in several cases been       |
+  |    changed to conform to the letters used in the illustrations.   |
+  |  - Minor typographical errors have been corrected.                |
+  |  - Except when mentioned here, inconsistencies in spelling        |
+  |    and hyphenation have not been corrected. Exceptions:           |
+  |      'Desagulier' to 'Desaguliers'                                |
+  |      'Séguin' to 'Seguin'                                         |
+  |      'Goldworthy Gurney' to 'Goldsworthy Gurney'                  |
+  |      'Ctesibus' to 'Ctesibius'                                    |
+  |      'i.e.' to 'i. e.'                                            |
+  |      'Warmetheorie' to 'Wärmetheorie'                             |
+  |      'tour a tour' to 'tour à tour'                               |
+  |      'the beam passes to the' to 'the steam passes to the'        |
+  |      'Desagulier' to 'Desaguliers'                                |
+  |      'éléver' to 'élever'.                                        |
+  |  - 'As early as 1743' moved to new paragraph.                     |
+  |  - 'A = 6.264035' changed to 'a = 6.264035.'                      |
+  |                                                                   |
+  +-------------------------------------------------------------------+
+
+
+
+
+                 THE INTERNATIONAL SCIENTIFIC SERIES.
+
+                            VOLUME XXIV.
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+          New York: D. APPLETON & CO., 1, 3, & 5 Bond Street.
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+
+
+
+         [Illustration: THE GRECIAN IDEA OF THE STEAM-ENGINE.]
+
+
+
+
+                  THE INTERNATIONAL SCIENTIFIC SERIES.
+
+                              A HISTORY
+                               OF THE
+                     GROWTH OF THE STEAM-ENGINE.
+
+                                  BY
+
+                  ROBERT H. THURSTON, A. M., C. E.,
+
+    PROFESSOR OF ENGINEERING STEVENS INSTITUTE OF TECHNOLOGY, PAST
+  PRESIDENT AMERICAN SOCIETY MECHANICAL ENGINEERS, MEMBER OF SOCIETY
+      OF CIVIL ENGINEERS, SOCIÉTÉ DES INGÉNIEURS CIVILS, VEREIN
+        DEUTSCHE INGENIEURE, OESTERREICHISCHER INGENIEUR- UND
+          ARCHITEKTEN-VEREIN; ASSOCIATE BRITISH INSTITUTION
+                  OF NAVAL ARCHITECTS, ETC., ETC.
+
+                     _SECOND REVISED EDITION._
+
+                             NEW YORK:
+                     D. APPLETON AND COMPANY,
+                     1, 3, AND 5 BOND STREET.
+                              1886.
+
+
+
+
+                      COPYRIGHT, 1878, 1884,
+                      BY ROBERT H. THURSTON.
+
+
+
+
+PREFACE.
+
+
+This little work embodies the more generally interesting portions of
+lectures first written for delivery at the STEVENS INSTITUTE OF
+TECHNOLOGY, in the winter of 1871-'72, to a mixed audience, composed,
+however, principally of engineers by profession, and of mechanics; it
+comprises, also, some material prepared for other occasions.
+
+These lectures have been rewritten and considerably extended, and have
+been given a form which is more appropriate to this method of
+presentation of the subject. The account of the gradual development of
+the philosophy of the steam-engine has been extended and considerably
+changed, both in arrangement and in method. That part in which the
+direction of improvement during the past history of the steam-engine,
+the course which it is to-day taking, and the direction and limitation
+of that improvement in the future, are traced, has been somewhat
+modified to accord with the character of the revised work.
+
+The author has consulted a large number of authors in the course of
+his work, and is very greatly indebted to several earlier writers. Of
+these, Stuart[1] is entitled to particular mention. His "History" is
+the earliest deserving the name; and his "Anecdotes" are of
+exceedingly great interest and of equally great historical value. The
+artistic and curious little sketches at the end of each chapter are
+from John Stuart, as are, usually, the drawings of the older forms of
+engines.
+
+  [1] "History of the Steam-Engine," London, 1824. "Anecdotes of the
+  Steam-Engine," London, 1829.
+
+Greenwood's excellent translation of Hero, as edited by Bennett
+Woodcroft (London, 1851), can be consulted by those who are curious to
+learn more of that interesting old Greek treatise.
+
+Some valuable matter is from Farey,[2] who gives the most extended
+account extant of Newcomen's and Watt's engines. The reader who
+desires to know more of the life of Worcester, and more of the details
+of his work, will find in the very complete biography of Dircks[3] all
+that he can wish to learn of that great but unfortunate inventor.
+Smiles's admirably written biography of Watt[4] gives an equally
+interesting and complete account of the great mechanic and of his
+partners; and Muirhead[5] furnishes us with a still more detailed
+account of his inventions.
+
+  [2] "Treatise on the Steam-Engine," London, 1827.
+
+  [3] "Life, Times, and Scientific Labors of the Second Marquis of
+  Worcester," London, 1865.
+
+  [4] "Lives of Boulton and Watt," London, 1865.
+
+  [5] "Life of James Watt," D. Appleton & Co., New York, 1859.
+  "Mechanical Inventions of James Watt," London, 1854.
+
+For an account of the life and work of John Elder, the great pioneer
+in the introduction of the now standard double-cylinder, or
+"compound," engine, the student can consult a little biographical
+sketch by Prof. Rankine, published soon after the death of Elder.
+
+The only published sketch of the history of the science of
+thermo-dynamics, which plays so large a part of the philosophy of the
+steam-engine, is that of Prof. Tait--a most valuable monograph.
+
+The section of this work which treats of the causes and the extent of
+losses of heat in the steam-engine, and of the methods available, or
+possibly available, to reduce the amount of this now immense waste of
+heat, is, in some respects, quite new, and is equally novel in the
+method of its presentation. The portraits with which the book is well
+furnished are believed to be authentic, and, it is hoped, will lend
+interest, if not adding to the real value of the work.
+
+Among other works which have been of great assistance to the author,
+and will be found, perhaps, equally valuable to some of the readers of
+this little treatise, are several to which reference has not been made
+in the text. Among them the following are deserving of special
+mention: Zeuner's "Wärmetheorie," the treatises of Stewart and of
+Maxwell, and McCulloch's "Mechanical Theory of Heat," a short but
+thoroughly logical and exact mathematical treatise; Cotterill's
+"Steam-Engine considered as a Heat-Engine," a more extended work on
+the same subject, which will be found an excellent companion to, and
+commentary upon, Rankine's "Steam-Engine and Prime Movers," which is
+the standard treatise on the theory of the steam-engine. The works of
+Bourne, of Holley, of Clarke, and of Forney, are standards on the
+practical every-day matters of steam-engine construction and
+management.
+
+The author is almost daily in receipt of inquiries which indicate that
+the above remarks will be of service to very many young engineers, as
+well as to many to whom the steam-engine is of interest from a more
+purely scientific point of view.
+
+
+
+
+                           CONTENTS.
+
+
+                          CHAPTER I.
+
+             THE STEAM-ENGINE AS A SIMPLE MACHINE.
+                                                                  PAGE
+  SECTION I.--THE PERIOD OF SPECULATION--FROM HERO TO WORCESTER,
+  B. C. 200 TO A. D. 1650                                            1
+
+  Introduction--the Importance of the Steam-Engine, 1; Hero and
+  his Treatise on Pneumatics, 4; Hero's Engines, B. C. 200, 8;
+  William of Malmesbury on Steam, A. D. 1150, 10; Hieronymus
+  Cardan on Steam and the Vacuum, 10; Malthesius on the Power of
+  Steam, A. D. 1571, 10; Jacob Besson on the Generation of Steam,
+  A. D. 1578, 11; Ramelli's Work on Machines, A. D. 1588, 11;
+  Leonardo da Vinci on the Steam-Gun, 12; Blasco de Garay's
+  Steamer, A. D. 1543, 12; Battista della Porta's Steam-Engine,
+  A. D. 1601, 13; Florence Rivault on the Force of Steam, A. D.
+  1608, 15; Solomon de Caus's Apparatus, A. D. 1615, 16; Giovanni
+  Branca's Steam-Engine, A. D. 1629, 16; David Ramseye's
+  Inventions, A. D. 1630, 17; Bishop John Wilkins's Schemes, A.
+  D. 1648, 18; Kircher's Apparatus, 19.
+
+  SECTION II.--THE PERIOD OF APPLICATION--WORCESTER, PAPIN, AND
+  SAVERY                                                            19
+
+  Edward Somerset, Marquis of Worcester, A. D. 1663, 19;
+  Worcester's Steam Pumping-Engines, 21; Jean Hautefeuille's
+  Alcohol and Gunpowder Engines, A. D. 1678, 24; Huyghens's
+  Gunpowder-Engine, A. D. 1680, 25; Invention in Great Britain,
+  26; Sir Samuel Morland, A. D. 1683, 27; Thomas Savery and his
+  Engine, A. D. 1698, 31; Desaguliers's Savery Engines, A. D.
+  1718, 41; Denys Papin and his Work, A. D. 1675, 45; Papin's
+  Engines, A. D. 1685-1695, 50; Papin's Steam-Boilers, 51.
+
+
+                             CHAPTER II.
+
+            THE STEAM-ENGINE AS A TRAIN OF MECHANISM.
+
+  THE MODERN TYPE AS DEVELOPED BY NEWCOMEN, BEIGHTON, AND SMEATON   55
+
+  Defects of the Savery Engine, 55; Thomas Newcomen, A. D. 1705,
+  57; the Newcomen Steam Pumping-Engine, 59; Advantages of
+  Newcomen's Engine, 60; Potter's and Beighton's Improvements, A.
+  D. 1713-'18, 61; Smeaton's Newcomen Engines, A. D. 1775, 64;
+  Operation of the Newcomen Engine, 65; Power and Economy of the
+  Engine, 69; Introduction of the Newcomen Engine, 70.
+
+
+                            CHAPTER III.
+
+  THE DEVELOPMENT OF THE MODERN STEAM-ENGINE. JAMES WATT AND HIS
+                           CONTEMPORARIES.
+
+  SECTION I.--JAMES WATT AND HIS INVENTIONS                         79
+
+  James Watt, his Birth and Parentage, 79; his Standing in
+  School, 81; he learns his Trade in London, 81; Return to
+  Scotland and Settlement in Glasgow, 82; the Newcomen Engine
+  Model, 83; Discovery of Latent Heat, 84; Sources of Loss in the
+  Newcomen Engine, 85; Facts experimentally determined by Watt,
+  86; Invention of the Separate Condenser, 87; the Steam-Jacket
+  and other Improvements, 90; Connection with Dr. Roebuck, 91;
+  Watt meets Boulton, 93; Matthew Boulton, 93; Boulton's
+  Establishment at Soho, 95; the Partnership of Boulton and Watt,
+  97; the Kinneil Engine, 97; Watt's Patent of 1769, 98; Work of
+  Boulton and Watt, 101; the Rotative Engine, 103; the Patent of
+  1781, 104; the Expansion of Steam--its Economy, 105; the
+  Double-Acting Engine, 110; the "Compound" Engine, 110; the
+  Steam-Hammer, 111; Parallel Motions, the Counter, 112; the
+  Throttle-Valve and Governor, 114; Steam, Vacuum, and Water
+  Gauges, 116; Boulton & Watt's Mill-Engine, 118; the Albion Mill
+  and its Engine, 119; the Steam-Engine Indicator, 123; Watt in
+  Social Life, 125; Discovery of the Composition of Water, 126;
+  Death of James Watt, 128; Memorials and Souvenirs, 128.
+
+  SECTION II.--THE CONTEMPORARIES OF JAMES WATT                    132
+
+  William Murdoch and his Work, 132; Invention of Gas-Lighting,
+  134; Jonathan Hornblower and the Compound Engine, 135; Causes
+  of the Failure of Hornblower, 137; William Bull and Richard
+  Trevithick, 138; Edward Cartwright and his Engine, 140.
+
+
+                           CHAPTER IV.
+
+                     THE MODERN STEAM-ENGINE.
+
+  THE SECOND PERIOD OF APPLICATION--1800-1850--STEAM-LOCOMOTION
+  ON RAILROADS                                                     144
+
+  Introduction, 144; the Non-Condensing Engine and the
+  Locomotive, 147; Newton's Locomotive, 1680, 149; Nathan Read's
+  Steam-Carriage, 150; Cugnot's Steam-Carriage, 1769, 151; the
+  Model Steam-Carriage of Watt and Murdoch, 1784, 153; Oliver
+  Evans and his Plans, 1786, 153; Evans's Oruktor Amphibolis,
+  1804, 157; Richard Trevithick's Steam-Carriage, 1802, 159;
+  Steam-Carriages of Griffiths and others, 160; Steam-Carriages
+  of Goldsworthy Gurney, 1827, 161; Steam-Carriages of Walter
+  Hancock, 1831, 165; Reports to the House of Commons, 1831, 170;
+  the Introduction of the Railroad, 172; Richard Trevithick's
+  Locomotives, 1804, 174; John Stevens and the Railroad, 1812,
+  178; William Hedley's Locomotives, 1812, 181; George
+  Stephenson, 183; Stephenson's Killingworth Engine, 1813, 186;
+  Stephenson's Second Locomotive, 1815, 187; Stephenson's
+  Safety-Lamp, 1815, 187; Robert Stephenson & Co., 1824, 190; the
+  Stockton & Darlington Engine, 1825, 191; the Liverpool &
+  Manchester Railroad, 1826, 193; Trial of Competing Engines at
+  Rainhill, 1829, 195; the Rocket and the Novelty, 198;
+  Atmospheric Railways, 201; Character of George Stephenson,
+  204; the Locomotive of 1833, 204; Introduction of Railroads in
+  Europe, 206; Introduction of Railroads in the United States,
+  207; John Stevens's Experimental Railroad, 1825, 207; Horatio
+  Allen and the "Stourbridge Lion," 1829, 208; Peter Cooper's
+  Engine, 1829, 209; E. L. Miller and the S. C. Railroad, 1830,
+  210; the "American" Type of Engine of John B. Jervis, 1832,
+  212; Robert L. Stevens and the T-rail, 1830, 214; Matthias W.
+  Baldwin and his Engine, 1831, 215; Robert Stephenson on the
+  Growth of the Locomotive, 220.
+
+
+                           CHAPTER V.
+
+                    THE MODERN STEAM-ENGINE.
+
+  THE SECOND PERIOD OF APPLICATION--1800-1850 (CONTINUED)--THE
+  STEAM-ENGINE APPLIED TO SHIP-PROPULSION                          221
+
+  Introduction, 221; Ancient Prophecies, 223; the Earliest
+  Paddle-Wheel, 223; Blasco de Garay's Steam-Vessel, 1543, 224;
+  Experiments of Dionysius Papin, 1707, 214; Jonathan Hulls's
+  Steamer, 1736, 225; Bernouilli and Gauthier, 228; William
+  Henry, 1782, 230; the Comte d'Auxiron, 1772, 232; the Marquis
+  de Jouffroy, 1776, 233; James Rumsey, 1774, 234; John Fitch,
+  1785, 285; Fitch's Experiments on the Delaware, 1787, 237;
+  Fitch's Experiments at New York, 1796, 240; the Prophecy of
+  John Fitch, 241; Patrick Miller, 1786-'87, 241; Samuel Morey,
+  1793, 243; Nathan Read, 1788, 244; Dundas and Symmington, 1801,
+  246; Henry Bell and the Comet, 1811, 248; Nicholas Roosevelt,
+  1798, 250; Robert Fulton, 1802, 251; Fulton's Torpedo-Vessels,
+  1801, 252; Fulton's First Steamboat, 1803, 253; the Clermont,
+  1807, 257; Voyage of the Clermont to Albany, 259; Fulton's
+  Later Steamboats, 260; Fulton's War-Steamer Fulton the First,
+  1815, 261; Oliver Evans, 1804, 263; John Stevens's
+  Screw-Steamer, 1804, 264; Stevens's Steam-Boilers, 1804, 264;
+  Stevens's Iron-Clad, 1812, 268; Robert L. Stevens's
+  Improvements, 270; the "Stevens Cut-off," 1841, 276; the
+  Stevens Iron-Clad, 1837, 277; Robert L. Thurston and John
+  Babcock, 1821, 280; James P. Allaire and the Messrs. Copeland,
+  281; Erastus W. Smith's Compound Engine, 283; Steam-Navigation
+  on Western Rivers, 1811, 283; Ocean Steam-Navigation, 1808,
+  285; the Savannah, 1819, 286; the Sirius and the Great Western,
+  1838, 289; the Cunard Line, 1840, 290; the Collins Line, 1851,
+  291; the Side-Lever Engine, 292; Introduction of
+  Screw-Steamers, 293; John Ericsson's Screw-Vessels, 1836, 294;
+  Francis Pettit Smith, 1837, 296; the Princeton, 1841, 297;
+  Advantages of the Screw, 299; the Screw on the Ocean, 300;
+  Obstacles to Improvement, 301; Changes in Engine-Construction,
+  302; Conclusion, 303.
+
+
+                           CHAPTER VI.
+
+                    THE STEAM-ENGINE OF TO-DAY.
+
+  THE PERIOD OF REFINEMENT--1850 TO DATE                           303
+
+  Condition of the Steam-Engine at this Time, 303; the Later
+  Development of the Engine, 304; Stationary Steam-Engines, 307;
+  the Steam-Engine for Small Powers, 307; the Horizontal Engine
+  with Meyer Valve-Gear, 311; the Allen Engine, 314; its
+  Performance, 316; the Detachable Valve-Gear, 316; the Sickels
+  Cut-off, 317; Expansion adjusted by the Governor, 318; the
+  Corliss Engine, 319; the Greene Engine, 321; Perkins's
+  Experiments, 323; Dr. Alban's Work, 325; the Perkins Compound
+  Engine, 327; the Modern Pumping-Engine, 328; the Cornish
+  Engine, 328; the Steam-Pump, 331; the Worthington
+  Pumping-Engine, 333; the Compound Beam and Crank Engine, 335;
+  the Leavitt Pumping-Engine, 336; the Stationary Steam-Boiler,
+  338; "Sectional" Steam-Boilers, 343; "Performance" of Boilers,
+  344.
+
+  SECTION II.--PORTABLE AND LOCOMOTIVE ENGINES.                    347
+
+  The Semi-Portable Engine, 348; Performance of Portable Engines,
+  350; their Efficiency, 352; the Hoadley Engine, 354; the Mills
+  Farm and Road Engine, 356; Fisher's Steam-Carriage, 356;
+  Performance of Road-Engines, 357; Trial of Road-Locomotives by
+  the Author, 358; Conclusions, 358; the Steam Fire-Engine, 360;
+  the Rotary Steam-Engine and Pump, 365; the Modern Locomotive,
+  368; Dimensions and Performance, 373; Compound Engines for
+  Locomotives, 376; Extent of Modern Railroads, 378;
+
+  SECTION III.--MARINE ENGINES.                                    379
+
+  The Modern Marine Engine, 379; the American Beam Engine, 379;
+  the Oscillating Engine and Feathering Wheel, 381; the two
+  "Rhode Islands," 382; River-Boat Engines on the Mississippi,
+  384; Steam Launches and Yachts, 386; Marine Screw-Engines, 389;
+  the Marine Compound Engine, 390; its Introduction by John Elder
+  and others, 393; Comparison with the Single-Cylinder Engine,
+  395; its Advantages, 396; the Surface Condenser, 397; Weight of
+  Machinery, 398; Marine Engine Performance, 398; Relative
+  Economy of Simple and Compound Engines, 399; the
+  Screw-Propeller, 399; Chain-Propulsion, or Wire-Rope Towage,
+  402; Marine Steam-Boilers, 403; the Modern Steamship, 405;
+  Examples of Merchant Steamers, 406; Naval
+  Steamers--Classification, 409; Examples of Iron-Clad Steamers,
+  412; Power of the Marine Engine, 415; Conclusion, 417.
+
+
+                          CHAPTER VII.
+
+              THE PHILOSOPHY OF THE STEAM-ENGINE.
+
+  THE HISTORY OF ITS GROWTH; ENERGETICS AND THERMO-DYNAMICS        419
+
+  General Outline, 419; Origin of its Power, 419; Scientific
+  Principles involved in its Operation, 420; the Beginnings of
+  Modern Science, 421; the Alexandrian Museum, 422; the
+  Aristotelian Philosophy, 424; the Middle Ages, 426; Galileo's
+  Work, 428; Da Vinci and Stevinus, 429; Kepler, Hooke, and
+  Huyghens, 429; Newton and the New Mechanical Philosophy, 430;
+  the Inception of the Science of Energetics, 483; the
+  Persistence of Energy, 433; Rumford's Experiments, 434;
+  Fourier, Carnot, Seguin, 437; Mayer and the Mechanical
+  Equivalent of Heat, 438; Joule's Determination of its Value,
+  438; Prof. Rankine's Investigations, 442; Clausius-Thompson's
+  Principles, 444; Experimental Work of Boyle, Black, and Watt,
+  446; Robison's, Dalton's, Ure's, and Biot's Study of Pressures
+  and Temperatures of Steam, 447; Arago's and Dulong's
+  Researches, 447; Franklin Institute Investigation, 447;
+  Cagniard de la Tour--Faraday, 447; Dr. Andrews and the Critical
+  Point, 448; Donny's and Dufour's Researches, 448; Regnault's
+  Determination of Temperatures and Pressures of Steam, 449;
+  Hirn's Experiments, 450; Résumé of the Philosophy of the
+  Steam-Engine, 451; Energy--Definitions and Principles, 451; its
+  Measure, 452; the Laws of Energetics, 453; Thermo-dynamics,
+  453; its Beginnings, 454; its Laws, 454; Rankine's General
+  Equation, 455; Rankine's Treatise on the Theory of
+  Heat-Engines, 456; Merits of the Great Philosopher, 456.
+
+
+                         CHAPTER VIII.
+
+              THE PHILOSOPHY OF THE STEAM-ENGINE.
+
+  ITS APPLICATION; ITS TEACHINGS RESPECTING THE CONSTRUCTION OF
+  THE ENGINE AND ITS IMPROVEMENT                                   457
+
+  Origin of all Energy, 457; the Progress of Energy through
+  Boiler and Engine, 458; Conditions of Heat-Development in the
+  Boiler, 458; the Steam in the Engine, 458; the Expansion of
+  Steam, 459; Conditions of Heat-Utilization, 460; Loss of Power
+  in the Engine, 462; Conditions affecting the Design of the
+  Steam-Engine, 466; the Problem stated, 466; Economy as affected
+  by Pressure and Temperature, 467; Changes which have already
+  occurred, 468; Direction of Changes now in Progress, 470;
+  Summary of Facts, 471; Characteristics of a Good Steam-Engine,
+  473; Principles of Steam-Boiler Construction, 476.
+
+
+
+
+                      LIST OF ILLUSTRATIONS.
+
+
+  FRONTISPIECE: The Grecian Idea of the Steam-Engine.
+
+  FIG.                                                            PAGE
+    1. Opening Temple-Doors by Steam, B. C. 200                      6
+    2. Steam Fountain, B. C. 200                                     7
+    3. Hero's Engine, B. C. 200                                      8
+    4. Porta's Apparatus, A. D. 1601                                14
+    5. De Caus's Apparatus, A. D. 1605                              15
+    6. Branca's Steam-Engine, A. D. 1629                            17
+    7. Worcester's Steam-Fountain, A. D. 1650                       21
+    8. Worcester's Engine, A. D. 1665                               22
+    9. Wall of Raglan Castle                                        22
+   10. Huyghens's Engine, 1680                                      26
+   11. Savery's Model, 1698                                         34
+   12. Savery's Engine, 1698                                        35
+   13. Savery's Engine, A. D. 1702                                  37
+   14. Papin's Two-Way Cock                                         42
+   15. Engine Built by Desaguliers in 1718                          43
+   16. Papin's Digester, 1680                                       48
+   17. Papin's Engine                                               50
+   18. Papin's Engine and Water-Wheel, A. D. 1707                   53
+   19. Newcomen's Engine, A. D. 1705                                59
+   20. Beighton's Valve-Gear, A. D. 1718                            63
+   21. Smeaton's Newcomen Engine                                    65
+   22. Boiler of Newcomen Engine, 1763                              67
+   23. Smeaton's Portable-Engine Boiler, 1765                       73
+   24. The Newcomen Model                                           84
+   25. Watt's Experiment                                            89
+   26. Watt's Engine, 1774                                          98
+   27. Watt's Engine, 1781                                         104
+   28. Expansion of Steam                                          108
+   29. The Governor                                                115
+   30. Mercury Steam-Gauge and Glass Water-Gauge                   117
+   31. Boulton & Watt's Double-Acting Engine, 1784                 119
+   32. Valve-Gear of the Albion Mills Engine                       121
+   33. Watt's Half-Trunk Engine, 1784                              122
+   34. The Watt Hammer, 1784                                       123
+   35. James Watt's Workshop                                       129
+   36. Murdoch's Oscillating Engine, 1785                          134
+   37. Hornblower's Compound Engine, 1781                          136
+   38. Bull's Pumping-Engine, 1798                                 139
+   39. Cartwright's Engine, 1798                                   141
+   40. The First Railroad-Car, 1825                                144
+   41. Leupold's Engine, 1720                                      148
+   42. Newton's Steam-Carriage, 1680                               149
+   43. Read's Steam-Carriage, 1790                                 150
+   44. Cugnot's Steam-Carriage, 1770                               151
+   45. Murdoch's Model, 1784                                       153
+   46. Evans's Non-Condensing Engine, 1800                         156
+   47. Evans's "Oruktor Amphibolis," 1804                          157
+   48. Gurney's Steam-Carriage                                     163
+   49. Hancock's "Autopsy", 1833                                   168
+   50. Trevithick's Locomotive, 1804                               175
+   51. Stephenson's Locomotive of 1815. Section                    187
+   52. Stephenson's No. 1 Engine, 1825                             191
+   53. Opening of the Stockton and Darlington Railroad, 1815       192
+   54. The "Novelty," 1829                                         197
+   55. The "Rocket," 1829                                          198
+   56. The Atmospheric Railroad                                    202
+   57. Stephenson's Locomotive, 1833                               203
+   58. The Stephenson Valve-Gear, 1833                             206
+   59. The "Atlantic," 1832                                        210
+   60. The "Best Friend," 1830                                     211
+   61. The "West Point," 1831                                      212
+   62. The "South Carolina," 1831                                  213
+   63. The "Stevens" Rail and Enlarged Section                     215
+   64. "Old Ironsides," 1832                                       216
+   65. The "E. L. Miller," 1834                                    217
+   66. Hulls's Steamboat, 1736                                     226
+   67. Fitch's Model, 1785                                         236
+   68. Fitch & Voight's Boiler, 1787                               238
+   69. Fitch's First Boat, 1787                                    238
+   70. John Fitch, 1788                                            239
+   71. John Fitch, 1796                                            240
+   72. Miller, Taylor & Symmington, 1788                           242
+   73. Read's Boiler in Section, 1788                              245
+   74. Read's Multi-Tubular Boiler, 1788                           245
+   75. The "Charlotte Dundas," 1801                                247
+   76. The "Comet," 1812                                           248
+   77. Fulton's Experiments                                        253
+   78. Fulton's Table of Resistances                               254
+   79. Barlow's Water-Tube Boiler, 1793                            256
+   80. The "Clermont," 1807                                        258
+   81. Engine of the "Clermont," 1808                              258
+   82. Launch of the "Fulton the First," 1804                      262
+   83. Section of Steam-Boiler, 1804                               264
+   84. Engine, Boiler, and Screw-Propellers used by Stevens, 1804  265
+   85. Stevens's Screw Steamer, 1804                               265
+   86. John Stevens's Twin-Screw Steamer, 1805                     269
+   87. The Feathering Paddle-Wheel                                 272
+   88. The "North America" and "Albany," 1827-'30                  274
+   89. Stevens's Return Tubular Boiler, 1832                       275
+   90. Stevens's Valve-Motion                                      276
+   91. The "Atlantic," 1851                                        290
+   92. The Side-Lever Engine, 1849                                 291
+   93. Vertical Stationary Steam-Engine                            308
+   94. Vertical Stationary Steam-Engine. Section                   309
+   95. Horizontal Stationary Steam-Engine                          312
+   96. Horizontal Stationary Steam-Engine                          313
+   97. Corliss Engine                                              319
+   98. Corliss Engine Valve-Motion                                 320
+   99. Greene Engine                                               321
+  100. Thurston's Greene-Engine Valve-Gear                         322
+  101. Cornish Pumping-Engine, 1880                                329
+  102. Steam-Pump                                                  331
+  103. The Worthington Pumping-Engine, 1876. Section               333
+  104. The Worthington Pumping-Engine                              334
+  105. Double-Cylinder Pumping-Engine, 1878                        335
+  106. The Lawrence Water-Works Engine                             336
+  107. The Leavitt Pumping-Engine                                  337
+  108. Babcock & Wilcox's Vertical Boiler                          341
+  109. Stationary "Locomotive" Boiler                              342
+  110. Galloway Tube                                               343
+  111. Harrison's Sectional Boiler                                 345
+  112. Babcock and Wilcox's Sectional Boiler                       346
+  113. Root Sectional Boiler                                       347
+  114. Semi-Portable Engine, 1878                                  348
+  115. Semi-Portable Engine, 1878                                  349
+  116. The Portable Steam-Engine, 1878                             354
+  117. The Thrashers' Road-Engine, 1878                            355
+  118. Fisher's Steam-Carriage                                     356
+  119. Road and Farm Locomotive                                    357
+  120. The Latta Steam Fire-Engine                                 361
+  121. The Amoskeag Engine. Section                                363
+  122. The Silsby Rotary Steam Fire-Engine                         364
+  123. Rotary Steam-Engine                                         365
+  124. Rotary Pump                                                 366
+  125. Tank Engine, New York Elevated Railroad                     369
+  126. Forney's Tank-Locomotive                                    370
+  127. British Express Engine                                      371
+  128. The Baldwin Locomotive. Section                             372
+  129. The American Type of Express Engine, 1878                   374
+  130. Beam Engine                                                 380
+  131. Oscillating Steam-Engine and Feathering Paddle-Wheel        381
+  132. The Two "Rhode Islands," 1836-1876                          383
+  133. A Mississippi Steamboat                                     384
+  134. Steam-Launch, New York Steam-Power Company                  386
+  135. Launch-Engine                                               387
+  136. Horizontal, Direct-acting Naval Screw Engine                389
+  137. Compound Marine Engine. Side Elevation                      390
+  138. Compound Marine Engine. Front Elevation and Section         391
+  139. Screw-Propeller                                             400
+  140. Tug-Boat Screw                                              401
+  141. Hirsch Screw                                                401
+  142. Marine Fire-Tubular Boiler. Section                         403
+  143. Marine High-Pressure Boiler. Section                        404
+  144. The Modern Steamship                                        407
+  145. Modern Iron-Clads                                           410
+  146. The "Great Eastern"                                         415
+  147. The "Great Eastern" at Sea                                  416
+
+
+
+
+                         PORTRAITS.
+
+
+  NO.                                                             PAGE
+   1. Edward Somerset, the Second Marquis of Worcester              20
+   2. Thomas Savery                                                 31
+   3. Denys Papin                                                   46
+   4. James Watt                                                    80
+   5. Matthew Boulton                                               94
+   6. Oliver Evans                                                 154
+   7. Richard Trevithick                                           174
+   8. Colonel John Stevens                                         178
+   9. George Stephenson                                            183
+  10. Robert Fulton                                                251
+  11. Robert L. Stevens                                            270
+  12. John Elder                                                   393
+  13. Benjamin Thompson, Count Rumford                             434
+  14. James Prescott Joule                                         439
+  15. Prof. W. J. M. Rankine                                       443
+
+
+
+
+  ["A Machine, receiving at distant times and from many hands new
+  combinations and improvements, and becoming at last of signal
+  benefit to mankind, may be compared to a rivulet swelled in its
+  course by tributary streams, until it rolls along a majestic river,
+  enriching, in its progress, provinces and kingdoms.
+
+  "In retracing the current, too, from where it mingles with the
+  ocean, the pretensions of even ample subsidiary streams are merged
+  in our admiration of the master-flood, glorying, as it were, in its
+  expansion. But as we continue to ascend, those waters which, nearer
+  the sea, would have been disregarded as unimportant, begin to rival
+  in magnitude and share our attention with the parent stream; until,
+  at length, on our approaching the fountains of the river, it appears
+  trickling from the rock, or oozing from among the flowers of the
+  valley.
+
+  "So, also, in developing the rise of a machine, a coarse instrument
+  or a toy may be recognized as the germ of that production of
+  mechanical genius, whose power and usefulness have stimulated our
+  curiosity to mark its changes and to trace its origin. The same
+  feelings of reverential gratitude which attached holiness to the
+  spot whence mighty rivers sprang, also clothed with divinity, and
+  raised altars in honor of, inventors of the saw, the plough, the
+  potter's wheel, and the loom."--STUART.]
+
+
+
+
+THE GROWTH OF THE STEAM-ENGINE.
+
+
+
+
+CHAPTER I.
+
+_THE STEAM-ENGINE AS A SIMPLE MACHINE._
+
+
+SECTION I.--THE PERIOD OF SPECULATION--FROM HERO TO WORCESTER, B. C.
+200 TO A. D. 1650.
+
+One of the greatest of modern philosophers--the founder of that system
+of scientific philosophy which traces the processes of evolution in
+every department, whether physical or intellectual--has devoted a
+chapter of his "First Principles" of the new system to the
+consideration of the multiplication of the effects of the various
+forces, social and other, which are continually modifying this
+wonderful and mysterious universe of which we form a part. Herbert
+Spencer, himself an engineer, there traces the wide-spreading,
+never-ceasing influences of new inventions, of the introduction of new
+forms of mechanism, and of the growth of industrial organization, with
+a clearness and a conciseness which are so eminently characteristic of
+his style. His illustration of this idea by reference to the manifold
+effects of the introduction of steam-power and its latest embodiment,
+the locomotive-engine, is one of the strongest passages in his work.
+The power of the steam-engine, and its inconceivable importance as an
+agent of civilization, has always been a favorite theme with
+philosophers and historians as well as poets. As Religion has always
+been, and still is, the great _moral_ agent in civilizing the world,
+and as Science is the great _intellectual_ promoter of civilization,
+so the Steam-Engine is, in modern times, the most important _physical_
+agent in that great work.
+
+It would be superfluous to attempt to enumerate the benefits which it
+has conferred upon the human race, for such an enumeration would
+include an addition to every comfort and the creation of almost every
+luxury that we now enjoy. The wonderful progress of the present
+century is, in a very great degree, due to the invention and
+improvement of the steam-engine, and to the ingenious application of
+its power to kinds of work that formerly taxed the physical energies
+of the human race. We cannot examine the methods and processes of any
+branch of industry without discovering, somewhere, the assistance and
+support of this wonderful machine. Relieving mankind from manual toil,
+it has left to the intellect the privilege of directing the power,
+formerly absorbed in physical labor, into other and more profitable
+channels. The intelligence which has thus conquered the powers of
+Nature, now finds itself free to do head-work; the force formerly
+utilized in the carrying of water and the hewing of wood, is now
+expended in the God-like work of THOUGHT. What, then, can be more
+interesting than to trace the history of the growth of this wonderful
+machine?--the greatest among the many great creations of one of God's
+most beneficent gifts to man--the power of invention.
+
+While following the records and traditions which relate to the
+steam-engine, I propose to call attention to the fact that its history
+illustrates the very important truth: _Great inventions are never, and
+great discoveries are seldom, the work of any one mind_. Every great
+invention is really either an aggregation of minor inventions, or the
+final step of a progression. It is not a creation, but _a growth_--as
+truly so as is that of the trees in the forest. Hence, the same
+invention is frequently brought out in several countries, and by
+several individuals, simultaneously. Frequently an important invention
+is made before the world is ready to receive it, and the unhappy
+inventor is taught, by his failure, that it is as unfortunate to be in
+advance of his age as to be behind it. Inventions only become
+successful when they are not only needed, but when mankind is so far
+advanced in intelligence as to appreciate and to express the necessity
+for them, and to at once make use of them.
+
+More than half a century ago, an able New England writer, in a
+communication to an English engineering periodical, described the new
+machinery which was built at Newport, R. I., by John Babcock and
+Robert L. Thurston, for one of the first steamboats that ever ran
+between that city and New York. He prefaced his description with a
+frequently-quoted remark to the effect that, as Minerva sprang, mature
+in mind, in full stature of body, and completely armed, from the head
+of Jupiter, so the steam-engine came forth, perfect at its birth, from
+the brain of James Watt. But we shall see, as we examine the records
+of its history, that, although James Watt was _an_ inventor, and
+probably the greatest of the inventors of the steam-engine, he was
+still but one of the many men who have aided in perfecting it, and who
+have now made us so familiar with it, and its tremendous power and its
+facile adaptations, that we have almost ceased to admire it, or to
+wonder at the workings of the still more admirable intelligence that
+has so far perfected it.
+
+Twenty-one centuries ago, the political power of Greece was broken,
+although Grecian civilization had risen to its zenith. Rome, ruder
+than her polished neighbor, was growing continually stronger, and was
+rapidly gaining territory by absorbing weaker states. Egypt, older in
+civilization than either Greece or Rome, fell but two centuries later
+before the assault of the younger states, and became a Roman province.
+Her principal city was at this time Alexandria, founded by the great
+soldier whose name it bears, when in the full tide of his prosperity.
+It had now become a great and prosperous city, the centre of the
+commerce of the world, the home of students and of learned men, and
+its population was the wealthiest and most civilized of the then known
+world.
+
+It is among the relics of that ancient Egyptian civilization that we
+find the first records in the early history of the steam-engine. In
+Alexandria, the home of Euclid, the great geometrician, and possibly
+contemporary with that talented engineer and mathematician,
+Archimedes, a learned writer, called Hero, produced a manuscript which
+he entitled "Spiritalia seu Pneumatica."
+
+It is quite uncertain whether Hero was the inventor of any number of
+the contrivances described in his work. It is most probable that the
+apparatus described are principally devices which had either been long
+known, or which were invented by Ctesibius, an inventor who was famous
+for the number and ingenuity of the hydraulic and pneumatic machines
+that he devised. Hero states, in his Introduction, his intention to
+describe existing machines and earlier inventions, and to add his own.
+Nothing in the text, however, indicates to whom the several machines
+are to be ascribed.[6]
+
+  [6] The British Museum contains four manuscript copies of Hero's
+  "Pneumatics," which were written in the fifteenth and sixteenth
+  centuries. These manuscripts have been examined with great care, and
+  a translation from them prepared by Prof. J. G. Greenwood, and
+  published at the desire of Mr. Bennett Woodcroft, the author of a
+  valuable little treatise on "Steam Navigation." This is, so far as
+  the author is aware, the only existing English translation of any
+  portion of Hero's works.
+
+The first part of Hero's work is devoted to applications of the
+syphon. The 11th proposition is the first application of heat to
+produce motion of fluids.
+
+An altar and its pedestal are hollow and air-tight. A liquid is poured
+into the pedestal, and a pipe inserted, of which the lower end passes
+beneath the surface of the liquid, and the upper extremity leads
+through a figure standing at the altar, and terminates in a vessel
+inverted above this altar. When a fire is made on the altar, the heat
+produced expands the confined air, and the liquid is driven up the
+tube, issuing from the vessel in the hand of the figure standing by
+the altar, which thus seems to be offering a libation. This toy
+embodies the essential principle of all modern heat-engines--the
+change of energy from the form known as heat-energy into mechanical
+energy, or work. It is not at all improbable that this prototype of
+the modern wonder-working machine may have been known centuries before
+the time of Hero.
+
+Many forms of hydraulic apparatus, including the hand fire-engine,
+which is familiar to us, and is still used in many of our smaller
+cities, are described, the greater number of which are probably
+attributable to Ctesibius. They demand no description here.
+
+A hot-air engine, however, which is the subject of his 37th
+proposition, is of real interest.
+
+Hero sketches and describes a method of opening temple-doors by the
+action of fire on an altar, which is an ingenious device, and contains
+all the elements of the machine of the Marquis of Worcester, which is
+generally considered the first real steam-engine, with the single and
+vital defect that the expanding fluid is air instead of steam. The
+sketch, from Greenwood's translation, exhibits the device very
+plainly. Beneath the temple-doors, in the space _A B C D_, is placed a
+spherical vessel, _H_, containing water. A pipe, _F G_, connects the
+upper part of this sphere with the hollow and air-tight shell of the
+altar above, _D E_. Another pipe, _K L M_, leads from the bottom of
+the vessel, _H_, over, in syphon-shape, to the bottom of a suspended
+bucket, _N X_. The suspending cord is carried over a pulley and led
+around two vertical barrels, _O P_, turning on pivots at their feet,
+and carrying the doors above. Ropes led over a pulley, _R_, sustain a
+counterbalance, _W_.
+
+[Illustration: FIG. 1.--Opening Temple-Doors by Steam, B. C. 200.]
+
+On building a fire on the altar, the heated air within expands, passes
+through the pipe, _F G_, and drives the water contained in the vessel,
+_H_, through the syphon, _K L M_, into the bucket, _N X_. The weight
+of the bucket, which then descends, turns the barrels, _O P_, raises
+the counterbalance, and opens the doors of the temple. On
+extinguishing the fire, the air is condensed, the water returns
+through the syphon from the bucket to the sphere, the counterbalance
+falls, and the doors are closed.
+
+Another contrivance is next described, in which the bucket is replaced
+by an air-tight bag, which, expanding as the heated air enters it,
+contracts vertically and actuates the mechanism, which in other
+respects is similar to that just described.
+
+In these devices the spherical vessel is a perfect anticipation of
+the vessels used many centuries later by several so-called inventors
+of the steam-engine.
+
+Proposition 45 describes the familiar experiment of a ball supported
+aloft by a jet of fluid. In this example steam is generated in a close
+cauldron, and issues from a pipe inserted in the top, the ball dancing
+on the issuing jet.
+
+No. 47 is a device subsequently reproduced--perhaps reinvented by the
+second Marquis of Worcester.
+
+[Illustration: FIG. 2.--Steam Fountain, B. C. 200.]
+
+A strong, close vessel, _A B C D_, forms a pedestal, on which are
+mounted a spherical vessel, _E F_, and a basin. A pipe, _H K_, is led
+from the bottom of the larger vessel into the upper part of the
+sphere, and another pipe from the lower part of the latter, in the
+form of a syphon, over to the basin, _M_. A drain-pipe, _N O_, leads
+from the basin to the reservoir, _A D_. The whole contrivance is
+called "A fountain which is made to flow by the action of the sun's
+rays."
+
+It is operated thus: The vessel, _E F_, being filled nearly to the top
+with water, or other liquid, and exposed to the action of the sun's
+rays, the air above the water expands, and drives the liquid over,
+through the syphon, _G_, into the basin, _M_, and it will fall into
+the pedestal, _A B C D_.
+
+Hero goes on to state that, on the removal of the sun's rays, the air
+in the sphere will contract, and that the water will be returned to
+the sphere from the pedestal. This can, evidently, only occur when the
+pipe _G_ is closed previous to the commencement of this cooling. No
+such cock is mentioned, and it is not unlikely that the device only
+existed on paper.
+
+Several steam-boilers are described, usually simple pipes or
+cylindrical vessels, and the steam generated in them by the heat of
+the fire on the altar forms a steam-blast. This blast is either
+directed into the fire, or it "makes a blackbird sing," blows a horn
+for a triton, or does other equally useless work. In one device, No.
+70, the steam issues from a reaction-wheel revolving in the horizontal
+plane, and causes dancing images to circle about the altar. A more
+mechanical and more generally-known form of this device is that which
+is frequently described as the "First Steam Engine." The sketch from
+Stuart is similar in general form, but more elaborate in detail, than
+that copied by Greenwood, which is here also reproduced, as
+representing more accurately the simple form which the mechanism of
+the "Æolipile," or Ball of Æolus, assumed in those early times.
+
+[Illustration: FIG. 3.--Hero's Engine, B. C. 200.]
+
+The cauldron, _A B_, contains water, and is covered by the steam-tight
+cover, _C D_. A globe is supported above the cauldron by a pair of
+tubes, terminating, the one, _C M_, in a pivot, _L_, and the other,
+_E F_, opening directly into the sphere at _G_. Short, bent pipes, _H_
+and _K_, issue from points diametrically opposite each other, and are
+open at their extremities.
+
+A fire being made beneath the cauldron, steam is formed and finds exit
+through the pipe, _E F G_, into the globe, and thence rushes out of
+the pipes, _H K_, turning the globe on its axis, _G L_, by the
+unbalanced pressure thus produced.
+
+The more elaborate sketch which forms the frontispiece represents a
+machine of similar character. Its design and ornamentation illustrate
+well the characteristics of ancient art, and the Greek idea of the
+steam-engine.
+
+This "Æolipile" consisted of a globe, _X_, suspended between
+trunnions, _O S_, through one of which steam enters from the boiler,
+_P_, below. The hollow, bent arms, _W_ and _Z_, cause the vapor to
+issue in such directions that the reaction produces a rotary movement
+of the globe, just as the rotation of reaction water-wheels is
+produced by the outflowing water.
+
+It is quite uncertain whether this machine was ever more than a toy,
+although it has been supposed by some authorities that it was actually
+used by the Greek priests for the purpose of producing motion of
+apparatus in their temples.
+
+It seems sufficiently remarkable that, while the power of steam had
+been, during all the many centuries that man has existed upon the
+globe, so universally displayed in so many of the phenomena of natural
+change, that mankind lived almost up to the Christian era without
+making it useful in giving motion even to a toy; but it excites still
+greater surprise that, from the time of Hero, we meet with no good
+evidence of its application to practical purposes for many hundreds of
+years.
+
+Here and there in the pages of history, and in special treatises, we
+find a hint that the knowledge of the force of steam was not lost; but
+it is not at all to the credit of biographers and of historians, that
+they have devoted so little time to the task of seeking and recording
+information relating to the progress of this and other important
+inventions and improvements in the mechanic arts.
+
+Malmesbury states[7] that, in the year A. D. 1125, there existed at
+Rheims, in the church of that town, a clock designed or constructed by
+Gerbert, a professor in the schools there, and an organ blown by air
+escaping from a vessel in which it was compressed "by heated water."
+
+  [7] Stuart's "Anecdotes."
+
+Hieronymus Cardan, a wonderful mathematical genius, a most eccentric
+philosopher, and a distinguished physician, about the middle of the
+sixteenth century called attention, in his writings, to the power of
+steam, and to the facility with which a vacuum can be obtained by its
+condensation. This Cardan was the author of "Cardan's Formula," or
+rule for the solution of cubic equations, and was the inventor of the
+"smoke-jack." He has been called a "philosopher, juggler, and madman."
+He was certainly a learned mathematician, a skillful physician, and a
+good mechanic.
+
+Many traces are found, in the history of the sixteenth century, of the
+existence of some knowledge of the properties of steam, and some
+anticipation of the advantages to follow its application. Matthesius,
+A. D. 1571, in one of his sermons describes a contrivance which may be
+termed a steam-engine, and enlarges on the "tremendous results which
+may follow the volcanic action of a small quantity of confined
+vapor;"[8] and another writer applied the steam æolipile of Hero to
+turn the spit, and thus rivaled and excelled Cardan, who was
+introducing his "smoke-jack."
+
+  [8] "Berg-Postilla, oder Sarepta von Bergwerk und Metallen."
+  Nuremberg, 1571.
+
+As Stuart says, the inventor enumerated its excellent qualities with
+great minuteness. He claimed that it would "eat nothing, and giving,
+withal, an assurance to those partaking of the feast, whose
+suspicious natures nurse queasy appetites, that the haunch has not
+been pawed by the turnspit in the absence of the housewife's eye, for
+the pleasure of licking his unclean fingers."[9]
+
+  [9] "History of the Steam-Engine," 1825.
+
+Jacob Besson, a Professor of Mathematics and Natural Philosophy at
+Orleans, and who was in his time distinguished as a mechanician, and
+for his ingenuity in contriving illustrative models for use in his
+lecture-room, left evidence, which Beroaldus collected and published
+in 1578,[10] that he had found the spirit of his time sufficiently
+enlightened to encourage him to pay great attention to applied
+mechanics and to mechanism. There was at this time a marked awakening
+of the more intelligent men of the age to the value of practical
+mechanics. A scientific tract, published at Orleans in 1569, and
+probably written by Besson, describes very intelligently the
+generation of steam by the communication of heat to water, and its
+peculiar properties.
+
+  [10] "Theatrum Instrumentorum et Machinarum, Jacobi Bessoni, cum
+  Franc Beroaldus, figuarum declaratione demonstrativa." Lugduni,
+  1578.
+
+The French were now becoming more interested in mechanics and the
+allied sciences, and philosophers and literati, of native birth and
+imported by the court from other countries, were learning more of the
+nature and importance of such studies as have a bearing upon the work
+of the engineer and of the mechanic.
+
+Agostino Ramelli, an Italian of good family, a student and an artist
+when at leisure, a soldier and an engineer in busier times, was born
+and educated at Rome, but subsequently was induced to make his home in
+Paris. He published a book in 1588,[11] in which he described many
+machines, adapted to various purposes, with a skill that was only
+equaled by the accuracy and general excellence of his delineations.
+This work was produced while its author was residing at the French
+capital, supported by a pension which had been awarded him by Henry
+III. as a reward for long and faithful services.
+
+  [11] "Le diverse et artificiose machine del Capitano Agostino
+  Ramelli, del Ponte della Prefia." Paris, 1588.
+
+The books of Besson and of Ramelli are the first treatises of
+importance on general machinery, and were, for many years, at once the
+sources from which later writers drew the principal portion of their
+information in relation to machinery, and wholesome stimulants to the
+study of mechanism. These works contain descriptions of many machines
+subsequently reinvented and claimed as new by other mechanics.
+
+Leonardo da Vinci, well known as a mathematician, engineer, poet, and
+painter, of the sixteenth century, describes, it is said, a steam-gun,
+which he calls the "Architonnerre," and ascribes to Archimedes. It was
+a machine composed of copper, and seems to have had considerable
+power. It threw a ball weighing a talent. The steam was generated by
+permitting water in a closed vessel to fall on surfaces heated by a
+charcoal fire, and by its sudden expansion to eject the ball.
+
+In the year 1825, the superintendent of the royal Spanish archives at
+Simancas furnished an account which, it was said, had been there
+discovered of an attempt, made in 1543 by Blasco de Garay, a Spanish
+navy-officer under Charles V., to move a ship by paddle-wheels,
+driven, as was inferred from the account, by a steam-engine.
+
+It is impossible to say to how much credit the story is entitled, but,
+if true, it was the first attempt, so far as is now known, to make
+steam useful in developing power for practical purposes. Nothing is
+known of the form of the engine employed, it only having been stated
+that a "vessel of boiling water" formed a part of the apparatus.
+
+The account is, however, in other respects so circumstantial, that it
+has been credited by many; but it is regarded as apocryphal by the
+majority of writers upon the subject. It was published in 1826 by M.
+de Navarrete, in Zach's "Astronomical Correspondence," in the form of
+a letter from Thomas Gonzales, Director of the Royal Archives at
+Simancas, Spain.
+
+In 1601, Giovanni Battista della Porta, in a work called "Spiritali,"
+described an apparatus by which the pressure of steam might be made to
+raise a column of water. It included the application of the
+condensation of steam to the production of a vacuum into which the
+water would flow.
+
+Porta is described as a mathematician, chemist, and physicist, a
+gentleman of fortune, and an enthusiastic student of science. His home
+in Naples was a rendezvous for students, artists, and men of science
+distinguished in every branch. He invented the magic lantern and the
+camera obscura, and described it in his commentary on the
+"Pneumatica." In his work,[12] he described this machine for raising
+water, as shown in Fig. 4, which differs from one shown by Hero in the
+use of steam pressure, instead of the pressure of heated air, for
+expelling the liquid.
+
+  [12] "Pneumaticorum libri tres," etc., 4to. Naples, 1601. "I Tre
+  Libri de' Spiritali." Napoli, 1606.
+
+The retort, or boiler, is fitted to a tank from which the bent pipe
+leads into the external air. A fire being kindled under the retort,
+the steam generated rises to the upper part of the tank, and its
+pressure on the surface of the water drives it out through the pipe,
+and it is then led to any desired height. This was called by Porta an
+improved "Hero's Fountain," and was named his "Steam Fountain." He
+described with perfect accuracy the action of condensation in
+producing a vacuum, and sketched an apparatus in which the vacuum thus
+secured was filled by water forced in by the pressure of the external
+atmosphere. His contrivances were not apparently ever applied to any
+practically useful purpose. We have not yet passed out of the age of
+speculation, and are just approaching the period of application. Porta
+is, nevertheless, entitled to credit as having proposed an essential
+change in this succession, which begins with Hero, and which did not
+end with Watt.
+
+[Illustration: FIG. 4.--Porta's Apparatus, A. D. 1601.]
+
+The use of steam in Hero's fountain was as necessary a step as,
+although less striking than, any of the subsequent modifications of
+the machine. In Porta's contrivance, too, we should note particularly
+the separation of the boiler from the "forcing vessel"--a plan often
+claimed as original with later inventors, and as constituting a fair
+ground for special distinction.
+
+The rude engraving (Fig. 4) above is copied from the book of Porta,
+and shows plainly the boiler mounted above a furnace, from the door of
+which the flame is seen issuing, and above is the tank containing
+water. The opening in the top is closed by the plug, as shown, and the
+steam issuing from the boiler into the tank near the top, the water
+is driven out through the pipe at the left, leading up from the bottom
+of the tank.
+
+[Illustration: FIG. 5.--De Caus's Apparatus, A. D. 1605.]
+
+Florence Rivault, a Gentleman of the Bedchamber to Henry IV., and a
+teacher of Louis XIII., is stated by M. Arago, the French philosopher,
+to have discovered, as early as 1605, that water confined in a
+bomb-shell and there heated would explode the shell, however thick its
+walls might be made. The fact was published in Rivault's treatise on
+artillery in 1608. He says: "The water is converted into air, and its
+vaporization is followed by violent explosion."
+
+In 1615, Salomon de Caus, who had been an engineer and architect under
+Louis XIII. of France, and later in the employ of the English Prince
+of Wales, published a work at Frankfort, entitled "Les Raisons des
+Forces Mouvantes, avec diverses machines tant utile que plaisante," in
+which he illustrated his proposition, "Water will, by the aid of fire,
+mount higher than its source," by describing a machine designed to
+raise water by the expanding power of steam.
+
+In the sketch here given (Fig. 5), and which is copied from the
+original in "Les Raisons des Forces Mouvantes," etc., _A_ is the
+copper ball containing water; _B_, the cock at the extremity of the
+pipe, taking water from the bottom, _C_, of the vessel; _D_, the cock
+through which the vessel is filled. The sketch was probably made by De
+Caus's own hand.
+
+The machine of De Caus, like that of Porta, thus consisted of a metal
+vessel partly filled with water, and in which a pipe was fitted,
+leading nearly to the bottom, and open at the top. Fire being applied,
+the steam formed by its elastic force drove the water out through the
+vertical pipe, raising it to a height limited only by either the
+desire of the builder or the strength of the vessel.
+
+In 1629, Giovanni Branca, of the Italian town of Loretto, described,
+in a work[13] published at Rome, a number of ingenious mechanical
+contrivances, among which was a steam-engine (Fig. 6), in which the
+steam, issuing from a boiler, impinged upon the vanes of a horizontal
+wheel. This it was proposed to apply to many useful purposes.
+
+  [13] "Le Machine deverse del Signior Giovanni Branca, cittadino
+  Romano, Ingegniero, Architetto della Sta. Casa di Loretto." Roma,
+  MDCXXIX.
+
+At this time experiments were in progress in England which soon
+resulted in the useful application of steam-power to raising water.
+
+[Illustration: FIG. 6.--Branca's Steam-Engine, A. D. 1629.]
+
+A patent, dated January 21, 1630, was granted to David Ramseye[14] by
+Charles I., which covered a number of distinct inventions. These were:
+"1. To multiply and make saltpeter in any open field, in fower acres
+of ground, sufficient to serve all our dominions. 2. To raise water
+from low pitts by fire. 3. To make any sort of mills to goe on
+standing waters by continual motion, without help of wind, water, or
+horse. 4. To make all sortes of tapistrie without any weaving-loom, or
+waie ever yet in use in this kingdome. 5. To make boats, shippes, and
+barges to goe against strong wind and tide. 6. To make the earth more
+fertile than usual. 7. To raise water from low places and mynes, and
+coal pitts, by a new waie never yet in use. 8. To make hard iron soft,
+and likewise copper to be tuffe and soft, which is not in use in this
+kingdome. 9. To make yellow waxe white verie speedilie."
+
+  [14] Rymer's "F[oe]dera," Sanderson. Ewbank's "Hydraulics," p. 419.
+
+This seems to have been the first authentic reference to the use of
+steam in the arts which has been found in English literature. The
+patentee held his grant fourteen years, on condition of paying an
+annual fee of £3 6_s._ 8_d._ to the Crown.
+
+The second claim is distinct as an application of steam, the language
+being that which was then, and for a century and a half subsequently,
+always employed in speaking of its use. The steam-engine, in all its
+forms, was at that time known as the "fire-engine." It would seem not
+at all improbable that the third, fifth, and seventh claims are also
+applications of steam-power.
+
+Thomas Grant, in 1632, and Edward Ford, in 1640, also patented
+schemes, which have not been described in detail, for moving ships
+against wind and tide by some new and great force.
+
+Dr. John Wilkins, Bishop of Chester, an eccentric but learned and
+acute scholar, described, in 1648, Cardan's smoke-jack, the earlier
+æolipiles, and the power of the confined steam, and suggested, in a
+humorous discourse, what he thought to be perfectly feasible--the
+construction of a flying-machine. He says: "Might not a 'high
+pressure' be applied with advantage to move wings as large as those of
+the 'ruck's' or the 'chariot'? The engineer might probably find a
+corner that would do for a coal-station near some of the 'castles'"
+(castles in the air). The reverend wit proposed the application of the
+smoke-jack to the chiming of bells, the reeling of yarn, and to
+rocking the cradle.
+
+Bishop Wilkins writes, in 1648 ("Mathematical Magic"), of æolipiles as
+familiar and useful pieces of apparatus, and describes them as
+consisting "of some such material as may endure the fire, having a
+small hole at which they are filled with water, and out of which (when
+the vessels are heated) the air doth issue forth with a strong and
+lasting violence." "They are," the bishop adds, "frequently used for
+the exciting and contracting of heat in the melting of glasses or
+metals. They may also be contrived to be serviceable for sundry other
+pleasant uses, as for the moving of sails in a chimney-corner, the
+motion of which sails may be applied to the turning of a spit, or the
+like."
+
+Kircher gives an engraving ("Mundus Subterraneus") showing the
+last-named application of the æolipile; and Erckern ("Aula
+Subterranea," 1672) gives a picture illustrating their application to
+the production of a blast in smelting ores. They seem to have been
+frequently used, and in all parts of Europe, during the seventeenth
+century, for blowing fires in houses, as well as in the practical work
+of the various trades, and for improving the draft of chimneys. The
+latter application is revived very frequently by the modern inventor.
+
+
+SECTION II.--THE PERIOD OF APPLICATION--WORCESTER, PAPIN, AND SAVERY.
+
+We next meet with the first instance in which the expansive force of
+steam is supposed to have actually been applied to do important and
+useful work.
+
+In 1663, Edward Somerset, second Marquis of Worcester, published a
+curious collection of descriptions of his inventions, couched in
+obscure and singular language, and called "A Century of the Names and
+Scantlings of Inventions by me already Practised."
+
+One of these inventions is an apparatus for raising water by steam.
+The description was not accompanied by a drawing, but the sketch here
+given (Fig. 7) is thought probably to resemble one of his earlier
+contrivances very closely.
+
+Steam is generated in the boiler _a_, and thence is led into the
+vessel _e_, already nearly filled with water, and fitted up like the
+apparatus of De Caus. It drives the water in a jet out through the
+pipe _f_. The vessel _e_ is then shut off from the boiler _a_, is
+again filled through the pipe _h_, and the operation is repeated.
+Stuart thinks it possible that the marquis may have even made an
+engine with a piston, and sketches it.[15] The instruments of Porta
+and of De Caus were "steam fountains," and were probably applied, if
+used at all, merely to ornamental purposes. That of the Marquis of
+Worcester was actually used for the purpose of elevating water for
+practical purposes at Vauxhall, near London.
+
+  [15] "Anecdotes of the Steam-Engine," vol. i., p. 61.
+
+[Illustration: Edward Somerset, the Second Marquis of Worcester.]
+
+How early this invention was introduced at Raglan Castle by Worcester
+is not known, but it was probably not much later than 1628. In 1647
+Dircks shows the marquis probably to have been engaged in getting out
+parts of the later engine which was erected at Vauxhall, obtaining
+his materials from William Lambert, a brass-founder. His patent was
+issued in June, 1663.
+
+[Illustration: FIG. 7.--Worcester's Steam Fountain, A. D. 1650.]
+
+We nowhere find an illustrated description of the machine, or such an
+account as would enable a mechanic to reproduce it in all its details.
+Fortunately, the cells and grooves (Fig. 9) remaining in the wall of
+the citadel of Raglan Castle indicate the general dimensions and
+arrangement of the engine; and Dircks, the biographer of the inventor,
+has suggested the form of apparatus shown in the sketch (Fig. 8) as
+most perfectly in accord with the evidence there found, and with the
+written specifications.
+
+The two vessels, _A A´_, are connected by a steam-pipe, _B B´_, with
+the boiler, _C_, behind them. _D_ is the furnace. A vertical
+water-pipe, _E_, is connected with the cold-water vessels, _A A´_, by
+the pipes, _F F´_, reaching nearly to the bottom. Water is supplied by
+the pipes, _G G´_, with valves, _a a´_, dipping into the well or
+ditch, _H_. Steam from the boiler being admitted to each vessel, _A_
+and _A´_, alternately, and there condensing, the vacuum formed permits
+the pressure of the atmosphere to force the water from the well
+through the pipes, _G_ and _G´_. While one is filling, the steam is
+forcing the charge of water from the other up the discharge-pipe, _E_.
+As soon as each is emptied, the steam is shut off from it and turned
+into the other, and the condensation of the steam remaining in the
+vessel permits it to fill again. As will be seen presently, this is
+substantially, and almost precisely, the form of engine of which the
+invention is usually attributed to Savery, a later inventor.
+
+[Illustration: FIG. 8.--Worcester's Engine, A. D. 1665.]
+
+[Illustration: FIG. 9.--Wall of Raglan Castle.]
+
+Worcester never succeeded in forming the great company which he hoped
+would introduce his invention on a scale commensurate with its
+importance, and his fate was that of nearly all inventors. He died
+poor and unsuccessful.
+
+His widow, who lived until 1681, seemed to have become as confident as
+was Worcester himself that the invention had value, and, long after
+his death, was still endeavoring to secure its introduction, but with
+equal non-success. The steam-engine had taken a form which made it
+inconceivably valuable to the world, at a time when no more efficient
+means of raising water was available at the most valuable mines than
+horse-power; but the people, greatly as it was needed, were not yet
+sufficiently intelligent to avail themselves of the great boon, the
+acceptance of which was urged upon them with all the persistence and
+earnestness which characterizes every true inventor.
+
+Worcester is described by his biographer as having been a learned,
+thoughtful, studious, and good man--a Romanist without prejudice or
+bigotry, a loyal subject, free from partisan intolerance; as a public
+man, upright, honorable, and humane; as a scholar, learned without
+being pedantic; as a mechanic, patient, skillful, persevering, and of
+wonderful ingenuity, and of clear, almost intuitive, apprehension.
+
+Yet, with all these natural advantages, reinforced as they were by
+immense wealth and influence in his earlier life, and by hardly
+lessened social and political influence when a large fortune had been
+spent in experiment, and after misfortune had subdued his spirits and
+left him without money or a home, the inventor failed to secure the
+introduction of a device which was needed more than any other.
+Worcester had attained practical success; but the period of
+speculation was but just closing, and that of the application of steam
+had not quite yet arrived.
+
+The second Marquis of Worcester stands on the record as the first
+steam-engine builder, and his death marks the termination of the first
+of those periods into which we have divided the history of the growth
+of the steam-engine.
+
+The "water-commanding engine," as its inventor called it, was the
+first instance in the history of the steam-engine in which the
+inventor is known to have "reduced his invention to practice."
+
+It is evident, however, that the invention of the separate boiler,
+important as it was, had been anticipated by Porta, and does not
+entitle the marquis to the honor, claimed for him by many English
+authorities, of being _the_ inventor of the steam-engine. Somerset was
+simply _one_ of those whose works collectively made the steam-engine.
+
+After the time of Worcester, we enter upon a stage of history which
+may properly be termed a period of application; and from this time
+forward steam continued to play a more and more important part in
+social economy, and its influence on the welfare of mankind augmented
+with a rapidly-increasing growth.
+
+The knowledge then existing of the immense expansive force of steam,
+and the belief that it was destined to submit to the control of man
+and to lend its immense power in every department of industry, were
+evidently not confined to any one nation. From Italy to Northern
+Germany, and from France to Great Britain, the distances, measured in
+time, were vastly greater then than now, when this wonderful genius
+has helped us to reduce weeks to hours; but there existed,
+notwithstanding, a very perfect system of communication, and the
+learning of every centre was promptly radiated to every other. It thus
+happened that, at this time, the speculative study of the steam-engine
+was confined to no part of Europe; inventors and experimenters were
+busy everywhere developing this promising scheme.
+
+Jean Hautefeuille, the son of a French _boulanger_, born at Orleans,
+adopted by the Duchess of Bouillon at the suggestion of De Sourdis,
+profiting by the great opportunities offered him, entered the Church,
+and became one of the most learned men and greatest mechanicians of
+his time. He studied the many schemes then brought forward by
+inventors with the greatest interest, and was himself prolific of new
+ideas.
+
+In 1678, he proposed the use of alcohol in an engine, "in such a
+manner that the liquid should evaporate and be condensed, _tour à
+tour_, without being wasted"[16]--the first recorded plan, probably,
+for surface-condensation and complete retention of the working-fluid.
+He proposed a gunpowder-engine, of which[17] he described three
+varieties.
+
+  [16] Stuart's "Anecdotes."
+
+  [17] "Pendule Perpetuelle, avec la manière d'élever d'eau par le
+  moyen de la poudre à canon," Paris, 1678.
+
+In one of these engines he displaced the atmosphere by the gases
+produced by the explosion, and the vacuum thus obtained was utilized
+in raising water by the pressure of the air. In the second machine,
+the pressure of the gases evolved by the combustion of the powder
+acted directly upon the water, forcing it upward; and in the third
+design, the pressure of the vapor drove a piston, and this engine was
+described as fitted to supply power for many purposes. There is no
+evidence that he constructed these machines, however, and they are
+here referred to simply as indicating that all the elements of the
+machine were becoming well known, and that an ingenious mechanic,
+combining known devices, could at this time have produced the
+steam-engine. Its early appearance should evidently have been
+anticipated.
+
+Hautefeuille, if we may judge from evidence at hand, was the first to
+propose the use of a piston in a heat-engine, and his gunpowder-engine
+seems to have been the first machine which would be called a
+heat-engine by the modern mechanic. The earlier "machines" or
+"engines," including that of Hero and those of the Marquis of
+Worcester, would rather be denominated "apparatus," as that term is
+used by the physicist or the chemist, than a machine or an engine, as
+the terms are used by the engineer.
+
+Huyghens, in 1680, in a memoir presented to the Academy of Sciences,
+speaks of the expansive force of gunpowder as capable of utilization
+as a convenient and portable mechanical power, and indicates that he
+had designed a machine in which it could be applied.
+
+This machine of Huyghens is of great interest, not simply because it
+was the first gas-engine and the prototype of the very successful
+modern explosive gas-engine of Otto and Langen, but principally as
+having been the first engine which consisted of a cylinder and piston.
+The sketch shows its form. It consisted of a cylinder, _A_, a piston,
+_B_, two relief-pipes, _C C_, fitted with check-valves and a system of
+pulleys, _F_, by which the weight is raised. The explosion of the
+powder at _H_ expels the air from the cylinder. When the products of
+combustion have cooled, the pressure of the atmosphere is no longer
+counterbalanced by that of air beneath, and the piston is forced down,
+raising the weight. The plan was never put in practice, although the
+invention was capable of being made a working and possibly useful
+machine.
+
+[Illustration: FIG. 10.--Huyghens's Engine, 1680.]
+
+At about this period the English attained some superiority over their
+neighbors on the Continent in the practical application of science and
+the development of the useful arts, and it has never since been lost.
+A sudden and great development of applied science and of the useful
+arts took place during the reign of Charles II., which is probably
+largely attributable to the interest taken by that monarch in many
+branches of construction and of science. He is said to have been very
+fond of mathematics, mechanics, chemistry, and natural history, and to
+have had a laboratory erected, and to have employed learned men to
+carry on experiments and lines of research for his satisfaction. He
+was especially fond of the study and investigation of the arts and
+sciences most closely related to naval architecture and navigation,
+and devoted much attention to the determination of the best forms of
+vessels, and to the discovery of the best kinds of ship-timber. His
+brother, the Duke of York, was equally fond of this study, and was his
+companion in some of his work.
+
+Great as is the influence of the monarch, to-day, in forming the
+tastes and habits and in determining the direction of the studies and
+labors of the people, his influence was vastly more potent in those
+earlier days; and it may well be believed that the rapid strides taken
+by Great Britain from that time were, in great degree, a consequence
+of the well-known habits of Charles II., and that the nation, which
+had an exceptional natural aptitude for mechanical pursuits, should
+have been prompted by the example of its king to enter upon such a
+course as resulted in the early attainment of an advanced position in
+all branches of applied science.
+
+The appointment, under Sir Robert Moray, the superintendent of the
+laboratory of the king, of Master Mechanic, was conferred upon Sir
+Samuel Morland, a nobleman who, in his practical knowledge of
+mechanics and in his ingenuity and fruitfulness of invention, was
+apparently almost equal to Worcester. He was the son of a Berkshire
+clergyman, was educated at Cambridge, where he studied mathematics
+with great interest, and entered public life soon after. He served the
+Parliament under Cromwell, and afterward went to Geneva. He was of a
+decidedly literary turn of mind, and wrote a history of the Piedmont
+churches, which gave him great repute with the Protestant party. He
+was induced subsequently, on the accession of Charles II., to take
+service under that monarch, whose gratitude he had earned by revealing
+a plot for his assassination.
+
+He received his appointment and a baronetcy in 1660, and immediately
+commenced making experiments, partly at his own expense and partly at
+the cost of the royal exchequer, which were usually not at all
+remunerative. He built hand fire-engines of various kinds, taking
+patents on them, which brought him as small profits as did his work
+for the king, and invented the speaking-trumpet, calculating machines,
+and a capstan. His house at Vauxhall was full of curious devices, the
+products of his own ingenuity.
+
+He devoted much attention to apparatus for raising water. His devices
+seem to have usually been modifications of the now familiar
+force-pump. They attracted much attention, and exhibitions were made
+of them before the king and queen and the court. He was sent to France
+on business relating to water-works erected for King Charles, and
+while in Paris he constructed pumps and pumping apparatus for the
+satisfaction of Louis XIV. In his book,[18] published in Paris in
+1683, and presented to the king, and an earlier manuscript,[19] still
+preserved in the British Museum, Morland shows a perfect familiarity
+with the power of steam. He says, in the latter: "Water being
+evaporated by fire, the vapors require a greater space (about two
+thousand times) than that occupied by the water; and, rather than
+submit to imprisonment, it will burst a piece of ordnance. But, being
+controlled according to the laws of statics, and, by science, reduced
+to the measure of weight and balance, it bears its burden peaceably
+(like good horses), and thus may be of great use to mankind,
+especially for the raising of water, according to the following table,
+which indicates the number of pounds which may be raised six inches,
+1,800 times an hour, by cylinders half-filled with water, and of the
+several diameters and depths of said cylinders."
+
+  [18] "Elevation des Eaux par toute sorte de Machines réduite à la
+  Mesure au Poids et à la Balance, présentée a Sa Majesté Très
+  Chrétienne, par le Chevalier Morland, Gentilhomme Ordinaire de la
+  Chambre Privée et Maistre de Mechaniques du Roy de la Grande
+  Bretagne, 1683."
+
+  [19] "Les Principes de la Nouvelle Force de Feu, inventée par le
+  Chevalier Morland, l'an 1682, et présentée a Sa Majesté Très
+  Chrétienne, 1683."
+
+He then gives the following table, a comparison of which with modern
+tables proves Morland to have acquired a very considerable and
+tolerably accurate knowledge of the volume and pressure of saturated
+steam:
+
+  -------------------------+------------------------
+         CYLINDERS.        |    POUNDS.
+  -----------+-------------+----------------------
+    Diameter |    Depth    |    Weight
+    in Feet. |   in Feet.  | to be Raised.
+  -----------+-------------+----------------------
+       1     |      2      |        15
+       2     |      4      |       120
+       3     |      6      |       405
+       4     |      8      |       960
+       5     |     10      |     1,876
+       6     |     10      |     3,240
+  -----------+-------------+----------------------
+   Number of cylinders having a diameter of 6 feet
+            and a depth of 12 feet.
+             |             |
+       1     |     12      |     3,240
+       2     |     12      |     6,480
+       3     |     12      |     9,720
+       4     |     12      |    12,960
+       5     |     12      |    16,200
+       6     |     12      |    19,440
+       7     |     12      |    22,680
+       8     |     12      |    25,920
+       9     |     12      |    29,190
+      10     |     12      |    32,400
+      20     |     12      |    64,800
+      30     |     12      |    97,200
+      40     |     12      |   129,600
+      50     |     12      |   162,000
+      60     |     12      |   194,400
+      70     |     12      |   226,800
+      80     |     12      |   259,200
+      90     |     12      |   291,600
+  -----------+-------------+----------------------
+
+The rate of enlargement of volume in the conversion of water into
+steam, as given in Morland's book, appears remarkably accurate when
+compared with statements made by other early experimenters.
+Desaguliers gave the ratio of volumes at 14,000, and this was accepted
+as correct for many years, and until Watt's experiments, which were
+quoted by Dr. Robison as giving the ratio at between 1,800 and 1,900.
+Morland also states the "duty" of his engines in the same manner in
+which it is stated by engineers to-day.
+
+Morland must undoubtedly have been acquainted with the work of his
+distinguished contemporary, Lord Worcester, and his apparatus seems
+most likely to have been a modification--perhaps improvement--of
+Worcester's engine. His house was at Vauxhall, and the establishment
+set up for the king was in the neighborhood. It may be that Morland is
+to be credited with greater success in the introduction of his
+predecessor's apparatus than the inventor himself.
+
+Dr. Hutton considered this book to have been the earliest account of
+the steam-engine, and accepts the date--1682--as that of the
+invention, and adds, that "the project seems to have remained obscure
+in both countries till 1699, when Savery, who probably knew more of
+Morland's invention than he owned, obtained a patent," etc. We have,
+however, scarcely more complete or accurate knowledge of the extent of
+Morland's work, and of its real value, than of that of Worcester.
+Morland died in 1696, at Hammersmith, not far from London, and his
+body lies in Fulham church.
+
+From this time forward the minds of many mechanicians were earnestly
+at work on this problem--the raising of water by aid of steam.
+Hitherto, although many ingenious toys, embodying the principles of
+the steam-engine separately, and sometimes to a certain extent
+collectively, had been proposed, and even occasionally constructed,
+the world was only just ready to profit by the labors of inventors in
+this direction.
+
+But, at the end of the seventeenth century, English miners were
+beginning to find the greatest difficulty in clearing their shafts of
+the vast quantities of water which they were meeting at the
+considerable depths to which they had penetrated, and it had become a
+matter of vital importance to them to find a more powerful aid in that
+work than was then available. They were, therefore, by their
+necessities stimulated to watch for, and to be prepared promptly to
+take advantage of, such an invention when it should be offered them.
+
+The experiments of Papin, and the practical application of known
+principles by Savery, placed the needed apparatus in their hands.
+
+[Illustration: Thomas Savery.]
+
+THOMAS SAVERY was a member of a well-known family of Devonshire,
+England, and was born at Shilston, about 1650. He was well educated,
+and became a military engineer. He exhibited great fondness for
+mechanics, and for mathematics and natural philosophy, and gave much
+time to experimenting, to the contriving of various kinds of
+apparatus, and to invention. He constructed a clock, which still
+remains in the family, and is considered an ingenious piece of
+mechanism, and is said to be of excellent workmanship.
+
+He invented and patented an arrangement of paddle-wheels, driven by a
+capstan[20] for propelling vessels in calm weather, and spent some
+time endeavoring to secure its adoption by the British Admiralty and
+the Navy Board, but met with no success. The principal objector was
+the Surveyor of the Navy, who dismissed Savery, with a remark which
+illustrates a spirit which, although not yet extinct, is less
+frequently met with in the public service now than then: "What have
+interloping people, that have no concern with us, to do to pretend to
+contrive or invent things for us?"[21] Savery then fitted his
+apparatus into a small vessel, and exhibited its operation on the
+Thames. The invention was never introduced into the navy, however.
+
+  [20] Harris, "Lexicon Technicum," London, 1710.
+
+  [21] "Navigation Improved; or, The Art of Rowing Ships of all rates
+  in Calms, with a more Easy, Swift, and Steady Motion, than Oars
+  can," etc., etc. By Thomas Savery, Gent. London, 1698.
+
+It was after this time that Savery became the inventor of a
+steam-engine. It is not known whether he was familiar with the work of
+Worcester, and of earlier inventors. Desaguliers[22] states that he
+had read the book of Worcester, and that he subsequently endeavored to
+destroy all evidence of the anticipation of his own invention by the
+marquis by buying up all copies of the century that he could find, and
+burning them. The story is scarcely credible. A comparison of the
+drawings given of the two engines exhibits, nevertheless, a striking
+resemblance; and, assuming that of the marquis's engine to be correct,
+Savery is to be given credit for the finally successful introduction
+of the "semi-omnipotent" "water-commanding" engine of Worcester.
+
+  [22] "Experimental Philosophy," vol. ii., p. 465.
+
+The most important advance in actual construction, therefore, was made
+by Thomas Savery. The constant and embarrassing expense, and the
+engineering difficulties presented by the necessity of keeping the
+British mines, and particularly the deep pits of Cornwall, free from
+water, and the failure of every attempt previously made to provide
+effective and economical pumping-machinery, were noted by Savery, who,
+July 25, 1698, patented the design of the first engine which was ever
+actually employed in this work. A working-model was submitted to the
+Royal Society of London in 1699, and successful experiments were made
+with it. Savery spent a considerable time in planning his engine and
+in perfecting it, and states that he expended large sums of money upon
+it.
+
+Having finally succeeded in satisfying himself with its operation, he
+exhibited a model "Fire-Engine," as it was called in those days,
+before King William III. and his court, at Hampton Court, in 1698, and
+obtained his patent without delay. The title of the patent reads: "A
+grant to Thomas Savery, Gentl., of the sole exercise of a new
+invention by him invented, for raising of water, and occasioning
+motion to all sorts of mill-works, by the impellant force of fire,
+which will be of great use for draining mines, serving towns with
+water, and for the working of all sorts of mills, when they have not
+the benefit of water nor constant winds; to hold for 14 years; with
+usual clauses."
+
+Savery now went about the work of introducing his invention in a way
+which is in marked contrast with that usually adopted by the inventors
+of that time. He commenced a systematic and successful system of
+advertisement, and lost no opportunity of making his plans not merely
+known, but well understood, even in matters of detail. The Royal
+Society was then fully organized, and at one of its meetings he
+obtained permission to appear with his model "fire-engine" and to
+explain its operation; and, as the minutes read, "Mr. Savery
+entertained the Society with showing his engine to raise water by the
+force of fire. He was thanked for showing the experiment, which
+succeeded, according to expectation, and was approved of." He
+presented to the Society a drawing and specifications of his machine,
+and "The Transactions"[23] contain a copperplate engraving and the
+description of his model. It consisted of a furnace, _A_, heating a
+boiler, _B_, which was connected by pipes, _C C_, with two copper
+receivers, _D D_. There were led from the bottom of these receivers
+branch pipes, _F F_, which turned upward, and were united to form a
+rising main, or "forcing-pipe," _G_. From the top of each receiver was
+led a pipe, which was turned downward, and these pipes united to form
+a suction-pipe, which was led down to the bottom of the well or
+reservoir from which the water was to be drawn. The maximum lift
+allowable was stated at 24 feet.
+
+  [23] "Philosophical Transactions, No. 252." Weld's "Royal Society,"
+  vol. i., p. 357. Lowthorp's "Abridgment," vol. i.
+
+[Illustration: FIG. 11.--Savery's Model, 1698.]
+
+The engine was worked as follows: Steam is raised in the boiler, _B_,
+and a cock, _C_, being opened, a receiver, _D_, is filled with steam.
+Closing the cock, _C_, the steam condensing in the receiver, a vacuum
+is created, and the pressure of the atmosphere forces the water up,
+through the supply-pipe, from the well into the receiver. Opening the
+cock, _C_, again, the check-valve in the suction-pipe at _E_ closes,
+the steam drives the water out through the forcing-pipe, _G_, the
+clack-valve, _E_, on that pipe opening before it, and the liquid is
+expelled from the top of the pipe. The valve, _C_, is again closed;
+the steam again condenses, and the engine is worked as before. While
+one of the two receivers is discharging, the other is filling, as in
+the machine of the Marquis of Worcester, and thus the steam is drawn
+from the boiler with tolerable regularity, and the expulsion of water
+takes place with similar uniformity, the two systems of receivers and
+pipes being worked alternately by the single boiler.
+
+In another and still simpler little machine,[24] which he erected at
+Kensington (Fig. 12), the same general plan was adopted, combining a
+suction-pipe, _A_, 16 feet long and 3 inches in diameter; a single
+receiver, _B_, capable of containing 13 gallons; a boiler, _C_, of
+about 40 gallons capacity; a forcing-pipe, _D_, 42 feet high, with the
+connecting pipe and cocks, _E F G_; and the method of operation was as
+already described, except that _surface-condensation_ was employed,
+the cock, _F_, being arranged to shower water from the rising main
+over the receiver, as shown. Of the first engine Switzer says: "I have
+heard him say myself, that the very first time he played, it was in a
+potter's house at Lambeth, where, though it was a small engine, yet it
+(the water) forced its way through the roof, and struck off the tiles
+in a manner that surprised all the spectators."
+
+  [24] Bradley, "New Improvements of Planting and Gardening." Switzer,
+  "Hydrostatics," 1729.
+
+[Illustration: FIG. 12.--Savery's Engine, 1698.]
+
+The Kensington engine cost £50, and raised 3,000 gallons per hour,
+filling the receiver four times a minute, and required a bushel of
+coal per day. Switzer remarks: "It must be noted that this engine is
+but a small one in comparison with many others that are made for
+coal-works; but this is sufficient for any reasonable family, and
+other uses required of it in watering all middling gardens." He
+cautions the operator: "When you have raised water enough, and you
+design to leave off working the engine, take away all the fire from
+under the boiler, and open the cock (connected to the funnel) to let
+out the steam, which would otherwise, were it to remain confined,
+perhaps burst the engine."
+
+With the intention of making his invention more generally known, and
+hoping to introduce it as a pumping-engine in the mining districts of
+Cornwall, Savery wrote a prospectus for general circulation, which
+contains the earliest account of the later and more effective form of
+engine. He entitled his pamphlet "The Miner's Friend; or, A
+Description of an Engine to raise Water by Fire described, and the
+Manner of fixing it in Mines, with an Account of the several Uses it
+is applicable to, and an Answer to the Objections against it." It was
+printed in London in 1702, for S. Crouch, and was distributed among
+the proprietors and managers of mines, who were then finding the flow
+of water at depths so great as, in some cases, to bar further
+progress. In many cases, the cost of drainage left no satisfactory
+margin of profit. In one mine, 500 horses were employed raising water,
+by the then usual method of using horse-gins and buckets.
+
+The approval of the King and of the Royal Society, and the countenance
+of the mine-adventurers of England, were acknowledged by the author,
+who addressed his pamphlet to them.
+
+The engraving of the engine was reproduced, with the description, in
+Harris's "Lexicon Technicum," 1704; in Switzer's "Hydrostatics," 1729;
+and in Desaguliers's "Experimental Philosophy," 1744.
+
+The sketch which here follows is a neater engraving of the same
+machine. Savery's engine is shown in Fig. 13, as described by Savery
+himself, in 1702, in "The Miner's Friend."
+
+_L_ is the boiler in which steam is raised, and through the pipes _O
+O_ it is alternately let into the vessels _P P_.
+
+[Illustration: FIG. 13.--Savery's Engine, A. D. 1702.]
+
+Suppose it to pass into the left-hand vessel first. The valve _M_
+being closed, and _R_ being opened, the water contained in _P_ is
+driven out and up the pipe _S_ to the desired height, where it is
+discharged.
+
+The valve _R_ is then closed, and the valve in the pipe _O_; the valve
+_M_ is next opened, and condensing water is turned upon the exterior
+of _P_ by the cock _Y_, leading water from the cistern _X_. As the
+steam contained in _P_ is condensed, forming a vacuum there, a fresh
+charge of water is driven by atmospheric pressure up the pipe _T_.
+
+Meantime, steam from the boiler has been let into the right-hand
+vessel _P_, the cock _W_ having been first closed, and _R_ opened.
+
+The charge of water is driven out through the lower pipe and the cock
+_R_, and up the pipe _S_ as before, while the other vessel is
+refilling preparatory to acting in its turn.
+
+The two vessels are thus alternately charged and discharged, as long
+as is necessary.
+
+Savery's method of supplying his boiler with water was at once simple
+and ingenious.
+
+The small boiler, _D_, is filled with water from any convenient
+source, as from the stand-pipe, _S_. A fire is then built under it,
+and, when the pressure of steam in _D_ becomes greater than in the
+main boiler, _L_, a communication is opened between their lower ends,
+and the water passes, under pressure, from the smaller to the larger
+boiler, which is thus "fed" without interrupting the work. _G_ and _N_
+are _gauge-cocks_, by which the height of water in the boilers is
+determined; they were first adopted by Savery.
+
+Here we find, therefore, the first really practicable and commercially
+valuable steam-engine. Thomas Savery is entitled to the credit of
+having been the first to introduce a machine in which the power of
+heat, acting through the medium of steam, was rendered generally
+useful.
+
+It will be noticed that Savery, like the Marquis of Worcester, used a
+boiler separate from the water-reservoir.
+
+He added to the "water-commanding engine" of the marquis the system of
+_surface-condensation_, by which he was enabled to charge his vessels
+when it became necessary to refill them; and added, also, the
+secondary boiler, which enabled him to supply the working-boiler with
+water without interrupting its work.
+
+The machine was thus made capable of working uninterruptedly for a
+period of time only limited by its own decay.
+
+Savery never fitted his boilers with safety-valves, although it was
+done earlier by Papin; and in deep mines he was compelled to make use
+of higher pressures than his rudely-constructed boilers could safely
+bear.
+
+Savery's engine was used at a number of mines, and also for supplying
+water to towns; some large estates, country houses, and other private
+establishments, employed them for the same purpose. They did not,
+however, come into general use among the mines, because, according to
+Desaguliers, they were apprehensive of danger from the explosion of
+the boilers or receivers. As Desaguliers wrote subsequently: "Savery
+made a great many experiments to bring this machine to perfection, and
+did erect several which raised water very well for gentlemen's seats,
+but could not succeed for mines, or supplying towns, where the water
+was to be raised very high and in great quantities; for then the steam
+required being boiled up to such a strength as to be ready to tear all
+the vessels to pieces." "I have known Captain Savery, at York's
+buildings, to make steam eight or ten times stronger than common air;
+and then its heat was so great that it would melt common soft solder,
+and its strength so great as to blow open several joints of the
+machine; so that he was forced to be at the pains and charge to have
+all his joints soldered with spelter or hard solder."
+
+Although there were other difficulties in the application of the
+Savery engine to many kinds of work, this was the most serious one,
+and explosions did occur with fatal results. The writer just quoted
+relates, in his "Experimental Philosophy," that a man who was ignorant
+of the nature of the engine undertook to work a machine which
+Desaguliers had provided with a safety-valve to avoid this very
+danger, "and, having hung the weight at the further end of the
+steelyard, in order to collect more steam in order to make his work
+the quicker, he hung also a very heavy plumber's iron upon the end of
+the steelyard; the consequence proved fatal; for, after some time, the
+steam, not being able, with the safety-cock, to raise up the steelyard
+loaded with all this unusual weight, burst the boiler with a great
+explosion, and killed the poor man." This is probably the earliest
+record of a steam-boiler explosion.
+
+Savery proposed to use his engine for driving mills; but there is no
+evidence that he actually made such an application of the machine,
+although it was afterward so applied by others. The engine was not
+well adapted to the drainage of surface-land, as the elevation of
+large quantities of water through small heights required great
+capacity of receivers, or compelled the use of several engines for
+each case. The filling of the receivers, in such cases, also compelled
+the heating of large areas of cold and wet metallic surfaces by the
+steam at each operation, and thus made the work comparatively wasteful
+of fuel. Where used in mines, they were necessarily placed within 30
+feet or less of the lowest level, and were therefore exposed to danger
+of submergence whenever, by any accident, the water should rise above
+that level. In many cases this would result in the loss of the engine,
+and the mine would remain "drowned," unless another engine should be
+procured to pump it out. Where the mine was deep, the water was forced
+by the pressure of steam from the level of the engine-station to the
+top of the lift. This compelled the use of pressures of several
+atmospheres in many cases; and a pressure of three atmospheres, or
+about 45 pounds per square inch, was considered, in those days, as
+about the maximum pressure allowable. This difficulty was met by
+setting a separate engine at every 60 or 80 feet, and pumping the
+water from one to the other. If any one engine in the set became
+disabled, the pumping was interrupted until that one machine could be
+repaired. The size of Savery's largest boilers was not great, their
+maximum diameter not exceeding two and a half feet. This made it
+necessary to provide several of his engines, usually, for a single
+mine, and at each level. The first cost and the expense of repairs
+were exceedingly serious items. The expense and danger, either real or
+apparent, were thus sufficient to deter many from their use, and the
+old method of raising water by horse-power was adhered to.
+
+The consumption of fuel with these engines was very great. The steam
+was not generated economically, as the boilers used were of such
+simple forms as only could then be produced, and presented too little
+heating surface to secure a very complete transfer of heat from the
+gases of combustion to the water within the boiler. This waste in the
+generation of steam in these uneconomical boilers was followed by
+still more serious waste in its application, without expansion, to the
+expulsion of water from a metallic receiver, the cold and wet sides of
+which absorbed heat with the greatest avidity. The great mass of the
+liquid was not, however, heated by the steam, and was expelled at the
+temperature at which it was raised from below.
+
+Savery quaintly relates the action of his machine in "The Miner's
+Friend," and so exactly, that a better description could scarcely be
+asked: "The steam acts upon the surface of the water in the receiver,
+which surface only being heated by the steam, it does not condense,
+but the steam gravitates or presses with an elastic quality like air,
+and still increasing its elasticity or spring, until it counterpoises,
+or rather exceeds, the weight of the column of water in the
+force-pipe, which then it will necessarily drive up that pipe; the
+steam then takes some time to recover its power, but it will at last
+discharge the water out at the top of the pipe. You may see on the
+outside of the receiver how the water goes out, as well as if it were
+transparent; for, so far as the steam is contained within the vessel,
+it is dry without, and so hot as scarcely to endure the least touch of
+the hand; but so far as the water is inside the vessel, it will be
+cold and wet on the outside, where any water has fallen on it; which
+cold and moisture vanish as fast as the steam takes the place of the
+water in its descent."
+
+After Savery's death, in 1716, several of these engines were erected
+in which some improvements were introduced. Dr. Desaguliers, in 1718,
+built a Savery engine, in which he avoided some defects which he, with
+Dr. Gravesande, had noted two years earlier. They had then proposed
+to adopt the arrangement of a single receiver which had been used by
+Savery himself, as already described, finding, by experiment on a
+model which they had made for the purpose, that one could be
+discharged three times, while the same boiler would empty two
+receivers but once each. In their arrangement, the steam was shut back
+in the boiler while the receiver was filling with water, and a high
+pressure thus accumulated, instead of being turned into the second
+receiver, and the pressure thus kept comparatively low.
+
+[Illustration: FIG. 14.--Papin's Two-Way Cock.]
+
+In the engine built in 1718, Desaguliers used a spherical boiler,
+which he provided with the lever safety-valve already applied by
+Papin, and adopted a comparatively small receiver--one-fifth the
+capacity of the boiler--of slender cylindrical form, and attached a
+pipe leading the water for condensation into the vessel, and effected
+its distribution by means of the "rose," or a "sprinkling-plate," such
+as is still frequently used in modern engines having jet-condensers.
+This substitution of jet for surface-condensation was of very great
+advantage, securing great promptness in the formation of a vacuum and
+a rapid filling of the receiver. A "two-way cock" admitted steam to
+the receiver, or, being turned the other way, admitted the cold
+condensing water. The dispersion of the water in minute streams or
+drops was a very important detail, not only as securing great
+rapidity of condensation, but enabling the designer to employ a
+comparatively small receiver or condenser.
+
+The engine is shown in Fig. 15, which is copied from the "Experimental
+Philosophy" of Desaguliers.
+
+[Illustration: FIG. 15.--Engine built by Desaguliers in 1718.]
+
+The receiver, _A_, is connected to the boiler, _B_, by a steam-pipe,
+_C_, terminating at the two-way cock, _D_; the "forcing-pipe," _E_,
+has at its foot a check-valve, _F_, and the valve _G_ is a similar
+check at the head of the suction-pipe. _H_ is a strainer, to prevent
+the ingress of chips or other bodies carried to the pipe by the
+current; the cap above the valves is secured by a bridle, or stirrup,
+and screw, _I_, and may be readily removed to clear the valves or to
+renew them; _K_ is the handle of the two-way cock; _M_ is the
+injection-cock, and is kept open during the working of the engine; _L_
+is the chimney-flue; _N_ and _O_ are gauge-cocks fitted to pipes
+leading to the proper depths within the boiler, the water-line being
+somewhere between the levels of their lower ends; _P_ is a lever
+safety-valve, as first used on the "Digester" of Papin; _R_ is the
+reservoir into which the water is pumped; _T_ is the flue, leading
+spirally about the boiler from the furnace, _V_, to the chimney; _Y_
+is a cock fitted in a pipe through which the rising-main may be filled
+from the reservoir, should injection-water be needed when that pipe is
+empty.
+
+Seven of these engines were built, the first of which was made for the
+Czar of Russia. Its boiler had a capacity of "five or six hogsheads,"
+and the receiver, "holding one hogshead," was filled and emptied four
+times a minute. The water was raised "by suction" 29 feet, and forced
+by steam pressure 11 feet higher.
+
+Another engine built at about this time, to raise water 29 feet "by
+suction," and to force it 24 feet higher, made 6 "strokes" per minute,
+and, when forcing water but 6 or 8 feet, made 8 or 9 strokes per
+minute. Twenty-five years later a workman overloaded the safety-valve
+of this engine, by placing the weight at the end and then adding "a
+very heavy plumber's iron." The boiler exploded, killing the
+attendant.
+
+Desaguliers says that one of these engines, capable of raising ten
+tons an hour 38 feet, in 1728 or 1729, cost £80, exclusive of the
+piping.
+
+Blakely, in 1766, patented an improved Savery engine, in which he
+endeavored to avoid the serious loss due to condensation of the steam
+by direct contact with the water, by interposing a cushion of oil,
+which floated upon the water and prevented the contact of the steam
+with the surface of the water beneath it. He also used air for the
+same purpose, sometimes in double receivers, one supported on the
+other. These plans did not, however, prove satisfactory.
+
+Rigley, of Manchester, England, soon after erected Savery engines, and
+applied them to the driving of mills, by pumping water into
+reservoirs, from whence it returned to the wells or ponds from which
+it had been raised, turning water-wheels as it descended.
+
+Such an arrangement was in operation many years at the works of a Mr.
+Kiers, St. Pancras, London. It is described in detail, and
+illustrated, in Nicholson's "Philosophical Journal," vol. i., p. 419.
+It had a "wagon-boiler" 7 feet long, 5 wide, and 5 deep; the wheel was
+18 feet in diameter, and drove the lathes and other machinery of the
+works. In this engine Blakely's plan of injecting air was adopted. The
+injection-valve was a clack, which closed automatically when the
+vacuum was formed.
+
+The engine consumed 6 or 7 bushels of good coals, and made 10 strokes
+per minute, raising 70 cubic feet of water 14 feet, and developing
+nearly 3 horse-power.
+
+Many years after Savery's death, in 1774, Smeaton made the first
+duty-trials of engines of this kind. He found that an engine having a
+cylindrical receiver 16 inches in diameter and 22 feet high,
+discharging the water raised 14 feet above the surface of the water in
+the well, making 12 strokes, and raising 100 cubic feet per minute,
+developed 2-2/3 horse-power, and consumed 3 hundredweight of coals in
+four hours. Its duty was, therefore, 5,250,000 pounds raised one foot
+per bushel of 84 pounds of coals, or 62,500 "foot-pounds" of work per
+pound of fuel. An engine of slightly greater size gave a duty about 5
+per cent. greater.
+
+When Louis XIV. revoked the edict of Nantes, by which Henry IV. had
+guaranteed protection to the Protestants of France, the terrible
+persecutions at once commenced drove from the kingdom some of its
+greatest men. Among these was Denys Papin.
+
+It was at about this time that the influence of the atmospheric
+pressure on the boiling-point began to be observed, Dr. Hooke having
+found that the boiling-point was a fixed temperature under the
+ordinary pressure of the atmosphere, and the increase in temperature
+and pressure of steam when confined having been shown by Papin with
+his "Digester."
+
+Denys Papin was of a family which had attached itself to the
+Protestant Church; but he was given his education in the school of the
+Jesuits at Blois, and there acquired his knowledge of mathematics. His
+medical education was given him at Paris, although he probably
+received his degree at Orleans. He settled in Paris in 1672, with the
+intention of practising his profession, and devoted all his spare
+time, apparently, to the study of physics.
+
+[Illustration: Denys Papin.]
+
+Meantime, that distinguished philosopher, Huyghens, the inventor of
+the clock and of the gunpowder-engine, had been induced by the
+linen-draper's apprentice, Colbert, now the most trusted adviser of
+the king, to take up his residence in Paris, and had been made one of
+the earliest members of the Academy of Science, which was founded at
+about that time. Papin became an assistant to Huyghens, and aided him
+in his experiments in mechanics, having been introduced by Madame
+Colbert, who was also a native of Blois. Here he devised several
+modifications of the instruments of Guericke, and printed a
+description of them.[25] This little book was presented to the
+Academy, and very favorably noticed. Papin now became well known among
+contemporary men of science at Paris, and was well received
+everywhere. Soon after, in the year 1675, as stated by the _Journal
+des Savants_, he left Paris and took up his residence in England,
+where he very soon made the acquaintance of Robert Boyle, the founder,
+and of the members of the Royal Society. Boyle speaks of Papin as
+having gone to England in the hope of finding a place in which he
+could satisfactorily pursue his favorite studies.
+
+  [25] "Nouvelles Expériences du Vuide, avec la description des
+  Machines qui servent à le faire." Paris, 1674.
+
+Boyle himself had already been long engaged in the study of
+pneumatics, and had been especially interested in the investigations
+which had been original with Guericke. He admitted young Papin into
+his laboratory, and the two philosophers worked together at these
+attractive problems. It was while working with Boyle that Papin
+invented the double air-pump and the air-gun.
+
+Papin and his work had now become so well known, and he had attained
+so high a position in science, that he was nominated for membership in
+the Royal Academy, and was elected December 16, 1680. He at once took
+his place among the most talented and distinguished of the great men
+of his time.
+
+He probably invented his "Digester" while in England, and it was first
+described in a brochure written in English, under the title, "The New
+Digester." It was subsequently published in Paris.[26] This was a
+vessel, _B_ (Fig. 16), capable of being tightly closed by a screw,
+_D_, and a lid, _C_, in which food could be cooked in water raised by
+a furnace, _A_, to the temperature due to any desired safe pressure of
+steam. The pressure was determined and limited by a weight, _W_, on
+the safety-valve lever, _G_. It is probable that this essential
+attachment to the steam-boiler had previously been used for other
+purposes; but Papin is given the credit of having first made use of it
+to control the pressure of steam.
+
+  [26] "La manière d'amollir les os et de faire cuire toutes sortes de
+  viandes," etc.
+
+[Illustration: FIG. 16.--Papin's Digester, 1680.]
+
+From England, Papin went to Italy, where he accepted membership and
+held official position in the Italian Academy of Science. Papin
+remained in Venice two years, and then returned to England. Here, in
+1687, he announced one of his inventions, which is just becoming of
+great value in the arts. He proposed to transmit power from one point
+to another, over long distances, by the now well-known "pneumatic"
+method. At the point where power was available, he exhausted a
+chamber by means of an air-pump, and, leading a pipe to the distant
+point at which it was to be utilized, there withdrew the air from
+behind a piston, and the pressure of the air upon the latter caused it
+to recede into the cylinder, in which it was fitted, raising a weight,
+of which the magnitude was proportionate to the size of the piston and
+the degree of exhaustion. Papin was not satisfactorily successful in
+his experiments; but he had created the germ of the modern system of
+pneumatic transmission of power. His disappointment at the result of
+his efforts to utilize the system was very great, and he became
+despondent, and anxious to change his location again.
+
+In 1687 he was offered the chair of Mathematics at Marburg by Charles,
+the Landgrave of Upper Hesse, and, accepting the appointment, went to
+Germany. He remained in Germany many years, and continued his
+researches with renewed activity and interest. His papers were
+published in the "Acta Eruditorum" at Leipsic, and in the
+"Philosophical Transactions" at London. It was while at Marburg that
+his papers descriptive of his method of pneumatic transmission of
+power were printed.[27]
+
+  [27] "Recueil des diverses Pieces touchant quelques Nouvelles
+  Machines et autres Sujets Philosophiques," M. D. Papin. Cassel,
+  1695.
+
+In the "Acta Eruditorum" of 1688 he exhibited a practicable plan, in
+which he exhausted the air from a set of engines or pumps by means of
+pumps situated at a long distance from the point of application of the
+power, and at the place where the prime mover--which was in this case
+a water-wheel--was erected.
+
+After his arrival at the University of Marburg, Papin exhibited
+to his colleagues in the faculty a modification of Huyghens's
+gunpowder-engine, in which he had endeavored to obtain a more perfect
+vacuum than had Huyghens in the first of these machines. Disappointed
+in this, he finally adopted the expedient of employing steam to
+displace the air, and to produce, by its condensation, the perfect
+vacuum which he sought; and he thus produced _the first steam-engine
+with a piston_, and the first piston steam-engine, in which
+condensation was produced to secure a vacuum. It was described in the
+"Acta" of Leipsic,[28] in June, 1690, under the title, "Nova Methodus
+ad vires motrices validissimas leri pretio comparandeo" ("A New Method
+of securing cheaply Motive Power of considerable Magnitude"). He
+describes first the gunpowder-engine, and continues by stating that,
+"until now, all experiments have been unsuccessful; and after the
+combustion of the exploded powder, there always remains in the
+cylinder about one-fifth its volume of air." He says that he has
+endeavored to arrive by another route at the same end; and "as, by a
+natural property of water, a small quantity of this liquid, vaporized
+by the action of heat, acquires an elasticity like that of the air,
+and returns to the liquid state again on cooling, without retaining
+the least trace of its elastic force," he thought that it would be
+easy to construct machines in which, "by means of a moderate heat, and
+without much expense," a more perfect vacuum could be produced than
+could be secured by the use of gunpowder.
+
+  [28] "Acta Eruditorum," Leipsic, 1690.
+
+[Illustration: FIG. 17.--Papin's Engine.]
+
+The first machine of Papin (Fig. 17) was very similar to the
+gunpowder-engine already described as the invention of Huyghens. In
+place of gunpowder, a small quantity of water is placed at the bottom
+of the cylinder, _A_; a fire is built beneath it, "the bottom being
+made of very thin metal," and the steam formed soon raises the piston,
+_B_, to the top, where a latch, _E_, engaging a notch in the
+piston-rod, _H_, holds it up until it is desired that it shall drop.
+The fire being removed, the steam condenses, and a vacuum is formed
+below the piston, and the latch, _E_, being disengaged, the piston is
+driven down by the superincumbent atmosphere and raises the weight
+which has been, meantime, attached to a rope, _L_, passing from the
+piston-rod over pulleys, _T T_. The machine had a cylinder two and a
+half inches in diameter, and raised 60 pounds once a minute; and Papin
+calculated that a machine of a little more than two feet diameter of
+cylinder and of four feet stroke would raise 8,000 pounds four feet
+per minute--i. e., that it would yield about one horse-power.
+
+The inventor claimed that this new machine would be found useful in
+relieving mines from water, in throwing bombs, in ship-propulsion,
+attaching revolving paddles--i. e., paddle-wheels--to the sides of the
+vessel, which wheels were to be driven by several of his engines, in
+order to secure continuous motion, the piston-rods being fitted with
+racks which were to engage ratchet-wheels on the paddle-shafts.
+
+"The principal difficulty," he says, answering anticipated objections,
+"is that of making these large cylinders."
+
+In a reprint describing his invention, in 1695, Papin gives a
+description of a "newly-invented furnace," a kind of fire-box
+steam-boiler, in which the fire, completely surrounded by water, makes
+steam so rapidly that his engine could be driven at the rate of four
+strokes per minute by the steam supplied by it.
+
+Papin also proposed the use of a peculiar form of furnace with this
+engine, which, embodying as it does some suggestions that very
+probably have since been attributed to later inventors, deserves
+special notice. In this furnace, Papin proposed to burn his fuel on a
+grate within a furnace arranged with a _down-draught_, the air
+entering above the grate, passing _down_ through the fire, and from
+the ash-pit through a side flue to the chimney. In starting the fire,
+the coal was laid on the grate, covered with wood, and the latter was
+ignited, the flame, passing downward through the coal, igniting that
+in turn, and, as claimed by Papin, the combustion was complete, and
+the formation of smoke was entirely prevented. He states, in "Acta
+Eruditorum," that the heat was intense, the saving of fuel very great,
+and that the only difficulty was to find a refractory material which
+would withstand the high temperature attained.
+
+This is the first fire-box and flue boiler of which we have record.
+The experiment is supposed to have led Papin to suggest the use of a
+hot-blast, as practised by Neilson more than a century later, for
+reducing metals from their ores.
+
+Papin made another boiler having a flue winding through the
+water-space, and presenting a heating surface of nearly 80 square
+feet. The flue had a length of 24 feet, and was about 10 inches
+square. It is not stated what were the maximum pressures carried on
+these boilers; but it is known that Papin had used very high pressures
+in his digesters--probably between 1,200 and 1,500 pounds per square
+inch.
+
+In the year 1705, Leibnitz, then visiting England, had seen a Savery
+engine, and, on his return, described it to Papin, sending him a
+sketch of the machine. Papin read the letter and exhibited the sketch
+to the Landgrave of Hesse, and Charles at once urged him to endeavor
+to perfect his own machine, and to continue the researches which he
+had been intermittently pursuing since the earlier machine had been
+exhibited in public.
+
+In a small pamphlet printed at Cassel in 1707,[29] Papin describes a
+new form of engine, in which he discards the original plan of a
+modified Huyghens engine, with tight-fitting piston and cylinder,
+raising its load by indirect action, and makes a modified Savery
+engine, which he calls the "Elector's Engine," in honor of his patron.
+This is the engine shown in the engraving, and as proposed to be used
+by him in turning a water-wheel.
+
+  [29] "Nouvelle manière d'élever l'Eau par la Force du Feu, mis en
+  Lumière," par D. Papin. Cassel, 1707.
+
+The sketch is that given by the inventor in his memoir. It consists
+(Fig. 18) of a steam-boiler, _a_, from which steam is led through the
+cock, _c_, to the working cylinder, _n n_. The water beneath the
+floating-piston, _h_, which latter serves simply as a cushion to
+protect the steam from sudden condensation or contact with the water,
+is forced into the vessel _r r_, which is a large air-chamber, and
+which serves to render the outflow of water comparatively uniform, and
+the discharge occurs by means of the pipe _q_, from which the water
+rises to the desired height. A fresh supply of water is introduced
+through the funnel _k_, after condensation of the steam in _n n_, and
+the operation of expulsion is repeated.
+
+[Illustration: FIG. 18.--Papin's Engine and Water-Wheel, A. D. 1707.]
+
+This machine is evidently a retrogression, and Papin, after having
+earned the honor of having invented the first steam-engine of the
+typical form which has since become so universally applied, forfeited
+that credit by his evident ignorance of its superiority over existing
+devices, and by attempting unsuccessfully to perfect the inferior
+device of another inventor.
+
+Subsequently, Papin made an attempt to apply the steam-engine to the
+propulsion of vessels, the account of which will be given in the
+chapter on Steam-Navigation.
+
+Again disappointed, Papin once more visited England, to renew his
+acquaintance with the _savans_ of the Royal Society; but Boyle had
+died during the period which Papin had spent in Germany, and the
+unhappy and disheartened inventor and philosopher died in 1810,
+without having seen any one of his many devices and ingenious
+inventions a practical success.
+
+[Illustration]
+
+
+
+
+CHAPTER II.
+
+_THE STEAM-ENGINE AS A TRAIN OF MECHANISM._
+
+  "The introduction of new Inventions seemeth to be the very chief of
+  all human Actions. The Benefits of new Inventions may extend to all
+  Mankind universally; but the Good of political Achievements can
+  respect but some particular Cantons of Men; these latter do not
+  endure above a few Ages, the former forever. Inventions make all Men
+  happy, without either Injury or Damage to any one single Person.
+  Furthermore, new Inventions are, as it were, new Erections and
+  Imitations of God's own Works."--BACON.
+
+
+THE MODERN TYPE, AS DEVELOPED BY NEWCOMEN, BEIGHTON, AND SMEATON.
+
+At the beginning of the eighteenth century every element of the modern
+type of steam-engine had been separately invented and practically
+applied. The character of atmospheric pressure, and of the pressure of
+gases, had become understood. The nature of a vacuum was known, and
+the method of obtaining it by the displacement of the air by steam,
+and by the condensation of the vapor, was understood. The importance
+of utilizing the power of steam, and the application of condensation
+in the removal of atmospheric pressure, was not only recognized, but
+had been actually and successfully attempted by Morland, Papin, and
+Savery.
+
+Mechanicians had succeeded in making steam-boilers capable of
+sustaining any desired or any useful pressure, and Papin had shown how
+to make them comparatively safe by the attachment of the
+safety-valve. They had made steam-cylinders fitted with pistons, and
+had used such a combination in the development of power.
+
+It now only remained for the engineer to combine known forms of
+mechanism in a practical machine which should be capable of
+economically and conveniently utilizing the power of steam through the
+application of now well-understood principles, and by the intelligent
+combination of physical phenomena already familiar to scientific
+investigators.
+
+Every essential fact and every vital principle had been learned, and
+every one of the needed mechanical combinations had been successfully
+effected. It was only requisite that an inventor should appear,
+capable of perceiving that these known facts and combinations of
+mechanism, properly illustrated in a working machine, would present to
+the world its greatest physical blessing.
+
+The defects of the simple engines constructed up to this time have
+been noted as each has been described. None of them could be depended
+upon for safe, economical, and continuous work. Savery's was the most
+successful of all. But the engine of Savery, even with the
+improvements of Desaguliers, was unsafe where most needed, because of
+the high pressures necessarily carried in its boilers when pumping
+from considerable depths; it was uneconomical, in consequence of the
+great loss of heat in its forcing-cylinders when the hot steam was
+surrounded at its entrance by colder bodies; it was slow in operation,
+of great first cost, and expensive in first cost and in repairs, as
+well as in its operation. It could not be relied upon to do its work
+uninterruptedly, and was thus in many respects a very unsatisfactory
+machine.
+
+The man who finally effected a combination of the elements of the
+modern steam-engine, and produced a machine which is unmistakably a
+true engine--i. e., a train of mechanism consisting of several
+elementary pieces combined in a train capable of transmitting a force
+applied at one end and of communicating it to the resistance to be
+overcome at the other end--was THOMAS NEWCOMEN, an "iron-monger" and
+blacksmith of Dartmouth, England. The engine invented by him, and
+known as the "Atmospheric Steam-Engine," is the first of an entirely
+new type.
+
+The old type of engine--the steam-engine as a simple machine--had been
+given as great a degree of perfection, by the successive improvements
+of Worcester, Savery, and Desaguliers, as it was probably capable of
+attaining by any modification of its details. The next step was
+necessarily a complete change of type; and to effect such a change, it
+was only necessary to combine devices already known and successfully
+tried.
+
+But little is known of the personal history of Newcomen. His position
+in life was humble, and the inventor was not then looked upon as an
+individual of even possible importance in the community. He was
+considered as one of an eccentric class of schemers, and of an order
+which, concerning itself with mechanical matters, held the lowest
+position in the class.
+
+It is supposed that Savery's engine was perfectly well known to
+Newcomen, and that the latter may have visited Savery at his home in
+Modbury, which was but fifteen miles from the residence of Newcomen.
+It is thought, by some biographers of these inventors, that Newcomen
+was employed by Savery in making the more intricate forgings of his
+engine. Harris, in his "Lexicon Technicum," states that drawings of
+the engine of Savery came into the hands of Newcomen, who made a model
+of the machine, set it up in his garden, and then attempted its
+improvement; but Switzer says that Newcomen "was as early in his
+invention as Mr. Savery was in his."
+
+Newcomen was assisted in his experiments by John Calley, who, with
+him, took out the patent. It has been stated that a visit to Cornwall,
+where they witnessed the working of a Savery engine, first turned
+their attention to the subject; but a friend of Savery has stated
+that Newcomen was as early with his general plans as Savery.
+
+After some discussion with Calley, Newcomen entered into
+correspondence with Dr. Hooke, proposing a steam-engine to consist of
+a _steam-cylinder containing a piston similar to that of Papin's, and
+to drive a separate pump_, similar to those generally in use where
+water was raised by horse or wind power. Dr. Hooke advised and argued
+strongly against their plan, but, fortunately, the obstinate belief of
+the unlearned mechanics was not overpowered by the disquisitions of
+their distinguished correspondent, and Newcomen and Calley attempted
+an engine on their peculiar plan. This succeeded so well as to induce
+them to continue their labors, and, in 1705, to patent,[30] in
+combination with Savery--who held the exclusive right to practise
+surface-condensation, and who induced them to allow him an interest
+with them--an engine combining a steam-cylinder and piston,
+surface-condensation, a separate boiler, and separate pumps.
+
+  [30] It has been denied that a patent was issued, but there is no
+  doubt that Savery claimed and received an interest in the new
+  engine.
+
+In the atmospheric-engine, as first designed, the slow process of
+condensation by the application of the condensing water to the
+exterior of the cylinder, to produce the vacuum, caused the strokes of
+the engine to take place at very long intervals. An improvement was,
+however, soon effected, which immensely increased the rapidity of
+condensation. A jet of water was thrown directly _into_ the cylinder,
+thus effecting for the Newcomen engine just what Desaguliers had done
+for the Savery engine previously. As thus improved, the Newcomen
+engine is shown in Fig. 19.
+
+Here _b_ is the boiler. Steam passes from it through the cock, _d_,
+and up into the cylinder, _a_, equilibrating the pressure of the
+atmosphere, and allowing the heavy pump-rod, _k_, to fall, and, by
+the greater weight acting through the beam, _i i_, to raise the
+piston, _s_, to the position shown. The rod _m_ carries a
+counterbalance, if needed. The cock _d_ being shut, _f_ is then
+opened, and a jet of water from the reservoir, _g_, enters the
+cylinder, producing a vacuum by the condensation of the steam. The
+pressure of the air above the piston now forces it down, again raising
+the pump-rods, and thus the engine works on indefinitely.
+
+[Illustration: FIG. 19.--Newcomen's Engine, A. D. 1705.]
+
+The pipe _h_ is used for the purpose of keeping the upper side of the
+piston covered with water, to prevent air-leaks--a device of Newcomen.
+Two gauge-cocks, _c c_, and a safety-valve, _N_, are represented in
+the figure, but it will be noticed that the latter is quite different
+from the now usual form. Here, the pressure used was hardly greater
+than that of the atmosphere, and the weight of the valve itself was
+ordinarily sufficient to keep it down. The condensing water, together
+with the water of condensation, flows off through the open pipe _p_.
+Newcomen's first engine made 6 or 8 strokes a minute; the later and
+improved engines made 10 or 12.
+
+The steam-engine has now assumed a form that somewhat resembles the
+modern machine.
+
+The Newcomen engine is seen at a glance to have been a combination of
+earlier ideas. It was the engine of Huyghens, with its cylinder and
+piston as improved by Papin, by the substitution of steam for the
+gases generated by the explosion of gunpowder; still further improved
+by Newcomen and Calley by the addition of the method of condensation
+used in the Savery engine. It was further modified, with the object of
+applying it directly to the working of the pumps of the mines by the
+introduction of the overhead beam, from which the piston was suspended
+at one end and the pump-rod at the other.
+
+The advantages secured by this combination of inventions were many and
+manifest. The piston not only gave economy by interposing itself
+between the impelling and the resisting fluid, but, by affording
+opportunity to make the area of piston as large as desired, it enabled
+Newcomen to use any convenient pressure and any desired proportions
+for any proposed lift. The removal of the water to be lifted from the
+steam-engine proper and handling it with pumps, was an evident cause
+of very great economy of steam.
+
+The disposal of the water to be raised in this way also permitted the
+operations of condensation of steam, and the renewal of pressure on
+the piston, to be made to succeed each other with rapidity, and
+enabled the inventor to choose, unhampered, the device for securing
+promptly the action of condensation.
+
+Desaguliers, in his account of the introduction of the engine of
+Newcomen, says that, with his coadjutor Calley, he "made several
+experiments in private about the year 1710, and in the latter end of
+the year 1711 made proposals to drain the water of a colliery at
+Griff, in Warwickshire, where the proprietors employed 500 horses, at
+an expense of £900 a year; but, their invention not meeting with the
+reception they expected, in March following, through the acquaintance
+of Mr. Potter, of Bromsgrove, in Worcestershire, they bargained to
+draw water for Mr. Back, of Wolverhampton, where, after a great many
+laborious attempts, they did make the engine work; but, not being
+either philosophers to understand the reason, or mathematicians enough
+to calculate the powers and proportions of the parts, they very
+luckily, by accident, found what they sought for.
+
+"They were at a loss about the pumps, but, being so near Birmingham,
+and having the assistance of so many admirable and ingenious workmen,
+they came, about 1712, to the method of making the pump-valves,
+clacks, and buckets, whereas they had but an imperfect notion of them
+before. One thing is very remarkable: as they were at first working,
+they were surprised to see the engine go several strokes, and very
+quick together, when, after a search, they found a hole in the piston,
+which let the cold water in to condense the steam in the inside of the
+cylinder, whereas, before, they had always done it on the outside.
+They used before to work with a buoy to the cylinder, inclosed in a
+pipe, which buoy rose when the steam was strong and opened the
+injection, and made a stroke; thereby they were only capable of giving
+6, 8, or 10 strokes in a minute, till a boy, named Humphrey Potter, in
+1713, who attended the engine, added (what he called a _scoggan_) a
+catch, that the beam always opened, and then it would go 15 or 16
+strokes a minute. But, this being perplexed with catches and strings,
+Mr. Henry Beighton, in an engine he had built at Newcastle-upon-Tyne
+in 1718, took them all away but the beam itself, and supplied them in
+a much better manner."
+
+In illustration of the application of the Newcomen engine to the
+drainage of mines, Farey describes a small machine, of which the pump
+is 8 inches in diameter, and the lift 162 feet. The column of water
+to be raised weighed 3,535 pounds. The steam-piston was made 2
+feet in diameter, giving an area of 452 square inches. The net
+working-pressure was assumed at 10-3/4 pounds per square inch; the
+temperature of the water of condensation and of uncondensed vapor
+after the entrance of the injection-water being usually about 150°
+Fahr. This gave an excess of pressure on the steam-side of 1,324
+pounds, the total pressure on the piston being 4,859 pounds. One-half
+of this excess is counterweighted by the pump-rods, and by weight on
+that end of the beam; and the weight, 662 pounds, acting on each side
+alternately as a surplus, produced the requisite rapidity of movement
+of the machine. This engine was said to make 15 strokes per minute,
+giving a speed of piston of 75 feet per minute, and the power exerted
+usefully was equivalent to 265,125 pounds raised one foot high per
+minute. As the horse-power is equivalent to 33,000 "foot-pounds" per
+minute, the engine was of 265125/33000 = 8.034--almost exactly 8
+horse-power.
+
+It is instructive to contrast this estimate with that made for a
+Savery engine doing the same work. The latter would have raised the
+water about 26 feet in its "suction-pipe," and would then have forced
+it, by the direct pressure of steam, the remaining distance of 136
+feet; and the steam-pressure required would have been nearly 60 pounds
+per square inch. With this high temperature and pressure, the waste of
+steam by condensation in the forcing-vessels would have been so great
+that it would have compelled the adoption of two engines of
+considerable size, each lifting the water one-half the height, and
+using steam of about 25 pounds pressure. Potter's rude valve-gear was
+soon improved by Henry Beighton, in an engine which that talented
+engineer erected at Newcastle-upon-Tyne in 1718, and in which he
+substituted substantial materials for the cords, as in Fig. 20.
+
+In this sketch, _r_ is a plug-tree, plug-rod, or plug-frame, as it is
+variously called, suspended from the great beam, with which it rises
+and falls, bringing the pins _p_ and _k_, at the proper moment, in
+contact with the handles _k k_ and _n n_ of the valves, moving them in
+the proper direction and to the proper extent. A lever safety-valve is
+here used, at the suggestion, it is said, of Desaguliers. The piston
+was packed with leather or with rope, and lubricated with tallow.
+
+[Illustration: FIG. 20.--Beighton's Valve-Gear, A. D. 1718.]
+
+After the death of Beighton, the atmospheric engine of Newcomen
+retained its then standard form for many years, and came into
+extensive use in all the mining districts, particularly in Cornwall,
+and was also applied occasionally to the drainage of wet lands, to the
+supply of water to towns, and it was even proposed by Hulls to be used
+for ship-propulsion.
+
+The proportions of the engines had been determined in a hap-hazard
+way, and they were in many cases very unsafe. John Smeaton, the most
+distinguished engineer of his time, finally, in 1769, experimentally
+determined proper proportions, and built several of these engines of
+very considerable size. He built his engines with steam-cylinders of
+greater length of stroke than had been customary, and gave them such
+dimensions as, by giving a greater excess of pressure on the
+steam-side, enabled him to obtain a greatly-increased speed of piston.
+The first of his new style of engine was erected at Long Benton, near
+Newcastle-upon-Tyne, in 1774.
+
+Fig. 21[31] illustrates its principal characteristic features. The
+boiler is not shown.
+
+  [31] A fac-simile of a sketch in Galloway's "On the Steam-Engine,"
+  etc.
+
+The steam is led to the engine through the pipe, _C_, and is regulated
+by turning the cock in the receiver, _D_, which connects with the
+steam-cylinder by the pipe, _E_, which latter pipe rises a little way
+above the bottom of the cylinder, _F_, in order that it may not drain
+off the injection-water into the steam-pipe and receiver.
+
+The steam-cylinder, about ten feet in length, is fitted with a
+carefully-made piston, _G_, having a flanch rising four or five inches
+and extending completely around its circumference, and nearly in
+contact with the interior surface of the cylinder. Between this flanch
+and the cylinder is driven a "packing" of oakum, which is held in
+place by weights; this prevents the leakage of air, water, or steam,
+past the piston, as it rises and falls in the cylinder at each stroke
+of the engine. The chain and piston-rod connect the piston to the
+beam, _I I_. The arch-heads at each end of the beam keep the chains of
+the piston-rod and the pump-rods perpendicular and in line.
+
+[Illustration: FIG. 21.--Smeaton's Newcomen Engine.]
+
+A "jack-head" pump, _N_, is driven by a small beam deriving its motion
+from the plug-rod at _g_, raises the water required for condensing
+the steam, and keeps the cistern, _O_, supplied. This "jack-head
+cistern" is sufficiently elevated to give the water entering the
+cylinder the velocity requisite to secure prompt condensation. A
+waste-pipe carries away any surplus water. The injection-water is led
+from the cistern by the pipe, _P P_, which is two or three inches in
+diameter, and the flow of water is regulated by the injection-cock,
+_r_. The cap at the end, _d_, is pierced with several holes, and the
+stream thus divided rises in jets when admitted, and, striking the
+lower side of the piston, the spray thus produced very rapidly
+condenses the steam, and produces a vacuum beneath the piston. The
+valve, _e_, on the upper end of the injection-pipe, is a check-valve,
+to prevent leakage into the engine when the latter is not in
+operation. The little pipe, _f_, supplies water to the upper side of
+the piston, and, keeping it flooded, prevents the entrance of air when
+the packing is not perfectly tight.
+
+The "working-plug," or plug-rod, _Q_, is a piece of timber slit
+vertically, and carrying pins which engage the handles of the valves,
+opening and closing them at the proper times. The steam-cock, or
+regulator, has a handle, _h_, by which it is moved. The iron rod, _i
+i_, or spanner, gives motion to the handle, _h_.
+
+The vibrating lever, _k l_, called the _Y_, or the "tumbling-bob,"
+moves on the pins, _m n_, and is worked by the levers, _o p_, which in
+turn are moved by the plug-tree. When _o_ is depressed, the loaded
+end, _k_, is given the position seen in the sketch, and the leg _l_ of
+the _Y_ strikes the spanner, _i i_, and, opening the steam-valve, the
+piston at once rises as steam enters the cylinder, until another pin
+on the plug-rod raises the piece, _P_, and closes the regulator again.
+The lever, _q r_, connects with the injection-cock, and is moved,
+when, as the piston rises, the end, _q_, is struck by a pin on the
+plug-rod, and the cock is opened and a vacuum produced. The cock is
+closed on the descent of the plug-tree with the piston. An
+eduction-pipe, _R_, fitted with a clock, conveys away the water in the
+cylinder at the end of each down-stroke; the water thus removed is
+collected in the hot-well, _S_, and is used as feed-water for the
+boiler, to which it is conveyed by the pipe _T_. At each down-stroke,
+while the water passes out through _R_, the air which may have
+collected in the cylinder is driven out through the "snifting-valve,"
+_s_. The steam-cylinder is supported on strong beams, _t t_; it has
+around its upper edge a guard, _v_, of lead, which prevents the
+overflow of the water on the top of the piston. The excess of this
+water flows away to the hot-well through the pipe _W_.
+
+Catch-pins, _x_, are provided, to prevent the beam descending too far
+should the engine make too long a stroke; two wooden springs, _y y_,
+receive the blow. The great beam is carried on sectors, _z z_, to
+diminish losses by friction.
+
+The boilers of Newcomen's earlier engines were made of copper where in
+contact with the products of combustion, and their upper parts were of
+lead. Subsequently, sheet-iron was substituted. The steam-space in the
+boiler was made of 8 or 10 times the capacity of the cylinder of the
+engine. Even in Smeaton's time, a chimney-damper was not used, and the
+supply of steam was consequently very variable. In the earlier
+engines, the cylinder was placed on the boiler; afterward, they were
+placed separately, and supported on a foundation of masonry. The
+injection or "jack-head" cistern was placed from 12 to 30 feet above
+the engine, the velocity due the greater altitude being found to give
+the most perfect distribution of the water and the promptest
+condensation.
+
+[Illustration: FIG. 22.--Boiler of Newcomen's Engine, 1768.]
+
+Smeaton covered the lower side of his steam-pistons with wooden plank
+about 2-1/4 inches thick, in order that it should absorb and waste
+less heat than when the iron was directly exposed to the steam. Mr.
+Beighton was the first to use the water of condensation for feeding
+the boiler, taking it directly from the eduction-pipe, or the
+"hot-well." Where only a sufficient amount of pure water could be
+obtained for feeding the boiler, and the injection-water was "hard,"
+Mr. Smeaton applied a heater, immersed in the hot-well, through which
+the feed passed, absorbing heat from the water of condensation _en
+route_ to the boiler. Farey first proposed the use of the
+"coil-heater"--a pipe, or "worm," which, forming a part of the
+feed-pipe, was set in the hot-well.
+
+As early as 1743, the metal used for the cylinders was cast-iron. The
+earlier engines had been fitted with brass cylinders. Desaguliers
+recommended the iron cylinders, as being smoother, thinner, and as
+having less capacity for heat than those of brass.
+
+In a very few years after the invention of Newcomen's engine it had
+been introduced into nearly all large mines in Great Britain; and many
+new mines, which could not have been worked at all previously, were
+opened, when it was found that the new machine could be relied upon to
+raise the large quantities of water to be handled. The first engine in
+Scotland was erected in 1720 at Elphinstone, in Stirlingshire. One was
+put up in Hungary in 1723.
+
+The first mine-engine, erected in 1712 at Griff, was 22 inches in
+diameter, and the second and third engines were of similar size. That
+erected at Ansthorpe was 23 inches in diameter of cylinder, and it was
+a long time before much larger engines were constructed. Smeaton and
+others finally made them as large as 6 feet in diameter.
+
+In calculating the lifting-power of his engines, Newcomen's method was
+"to square the diameter of the cylinder in inches, and, cutting off
+the last figure, he called it 'long hundredweights;' then writing a
+cipher on the right hand, he called the number on that side 'odd
+pounds;' this he reckoned tolerably exact at a mean, or rather when
+the barometer was above 30 inches, and the air heavy." In allowing for
+frictional and other losses, he deducted from one-fourth to one-third.
+Desaguliers found the rule quite exact. The usual mean pressure
+resisting the motion of the piston averaged, in the best engines,
+about 8 pounds per square inch of its area. The speed of the piston
+was from 150 to 175 feet per minute. The temperature of the hot-well
+was from 145° to 175° Fahr.
+
+Smeaton made a number of test-trials of Newcomen engines to determine
+their "duty"--i. e., to ascertain the expenditure of fuel required to
+raise a definite quantity of water to a stated height. He found an
+engine 10 inches in diameter of cylinder, and of 3 feet stroke, could
+do work equal to raising 2,919,017 pounds of water one foot high, with
+a bushel of coals weighing 84 pounds.
+
+One of Smeaton's larger engines, erected at Long Benton, was 52 inches
+in diameter of cylinder and of 7 feet stroke of piston, and made 12
+strokes per minute. Its load was equal to 7-1/2 pounds per square inch
+of piston-area, and its effective capacity about 40 horse-power. Its
+duty was 9-1/2 millions of pounds raised one foot high per bushel of
+coals. Its boiler evaporated 7.88 pounds of water per pound of fuel
+consumed. It had 35 square feet of grate-surface and 142 square feet
+of heating-surface beneath the boilers, and 317 square feet in the
+flues--a total of 459 square feet. The moving parts of this engine
+weighed 8-1/2 tons.
+
+Smeaton erected one of these engines at the Chasewater mine, in
+Cornwall, in 1775, which was of very considerable size. It was 6 feet
+in diameter of steam-cylinder, and had a maximum stroke of piston of
+9-1/2 feet. It usually worked 9 feet. The pumps were in three lifts of
+about 100 feet each, and were 16-3/4 inches in diameter. Nine strokes
+were made per minute. This engine replaced two others, of 64 and of 62
+inches diameter of cylinder respectively, and both of 6 feet stroke.
+One engine at the lower lift supplied the second, which was set above
+it. The lower one had pumps 18-1/2 inches in diameter, and raised the
+water 144 feet; the upper engine raised the water 156 feet, by pumps
+17-1/2 inches in diameter. The later engine replacing them exerted
+76-1/2 horse-power. There were three boilers, each 15 feet in
+diameter, and having each 23 square feet of grate-surface. The chimney
+was 22 feet high. The great beam, or "lever," of this engine was built
+up of 20 beams of fir in two sets, placed side by side, and ten deep,
+strongly bolted together. It was over 6 feet deep at the middle and 5
+feet at the ends, and was 2 feet thick. The "main centres," or
+journals, on which it vibrated were 8-1/2 inches in diameter and 8-1/2
+inches long. The cylinder weighed 6-1/2 tons, and was paid for at the
+rate of 28 shillings per hundredweight.
+
+By the end of the eighteenth century, therefore, the engine of
+Newcomen, perfected by the ingenuity of Potter and of Beighton, and by
+the systematic study and experimental research of Smeaton, had become
+a well-established form of steam-engine, and its application to
+raising water had become general. The coal-mines of Coventry and of
+Newcastle had adopted this method of drainage; and the tin and the
+copper mines of Cornwall had been deepened, using, for drainage,
+engines of the largest size.
+
+Some engines had been set up in and about London, the scene of
+Worcester's struggles and disappointments, where they were used to
+supply water to large houses. Others were in use in other large cities
+of England, where water-works had been erected.
+
+Some engines had also been erected to drive mills indirectly by
+raising water to turn water-wheels. This is said by Farey to have been
+first practised in 1752, at a mill near Bristol, and became common
+during the next quarter of a century. Many engines had been built in
+England and sent across the channel, to be applied to the drainage of
+mines on the Continent. Belidor[32] stated that the manufacture of
+these "fire-engines" was exclusively confined to England; and this
+remained true many years after his time. When used for the drainage of
+mines, the engine usually worked the ordinary lift or bucket pump;
+when employed for water-supply to cities, the force or plunger pump
+was often employed, the engine being placed below the level of the
+reservoir. Dr. Rees states that this engine was in common use among
+the collieries of England as early as 1725.
+
+  [32] "Architecture Hydraulique," 1734.
+
+The Edmonstone colliery was licensed, in 1725, to erect an engine, not
+to exceed 28 inches diameter of cylinder and 9 feet stroke of piston,
+paying a royalty of £80 per annum for eight years. This engine was
+built in Scotland, by workmen sent from England, and cost about
+£1,200. Its "great cost" is attributed to an extensive use of brass.
+The workmen were paid their expenses and 15_s._ per week as wages. The
+builders were John and Abraham Potter, of Durham. An engine built in
+1775, having a steam-cylinder 48 inches in diameter and of 7 feet
+stroke, cost about £2,000.
+
+Smeaton found 57 engines at work near Newcastle in 1767, ranging in
+size from 28 to 75 inches in diameter of cylinder, and of,
+collectively, about 1,200 horse-power. Fifteen of these engines gave
+an average of 98 square inches of piston to the horse-power, and the
+average duty was 5,590,000 pounds raised 1 foot high by 1 bushel (84
+pounds) of coal. The highest duty noted was 7.44 millions; the lowest
+was 3.22 millions. The most efficient engine had a steam-cylinder 42
+inches in diameter; the load was equivalent to 9-1/4 pounds per square
+inch of piston-area, and the horse-power developed was calculated to
+be 16.7.
+
+Price, writing in 1778, says, in the Appendix to his "Mineralogia
+Cornubiensis:" "Mr. Newcomen's invention of the fire-engine enabled us
+to sink our mines to twice the depth we could formerly do by any other
+machinery. Since this invention was completed, most other attempts at
+its improvement have been very unsuccessful; but the vast consumption
+of fuel in these engines is an immense drawback on the profit of our
+mines, for every fire-engine of magnitude consumes £3,000 worth of
+coals per annum. This heavy tax amounts almost to a prohibition."
+
+Smeaton was given the description, in 1773, of a _stone_ boiler, which
+was used with one of these engines at a copper mine at Camborne, in
+Cornwall. It contained three copper flues 22 inches in diameter. The
+gases were passed through these flues successively, finally passing
+off to the chimney. This boiler was cemented with hydraulic mortar. It
+was 20 feet long, 9 feet wide, and 8-1/2 feet deep. It was heated by
+the waste heat from the roasting-furnaces. This was one of the
+earliest flue-boilers ever made.
+
+In 1780, Smeaton had a list of 18 large engines working in Cornwall.
+The larger number of them were built by Jonathan Hornblower and John
+Nancarron. At this time, the largest and best-known pumping-engine for
+water-works was at York Buildings, in Villiers Street, Strand, London.
+It had been in operation since 1752, and was erected beside one of
+Savery's engines, built in 1710. It had a steam-cylinder 45 inches in
+diameter, and a stroke of piston of 8 feet, making 7-1/2 strokes per
+minute, and developing 35-1/2 horse-power. Its boiler was dome-shaped,
+of copper, and contained a large central fire-box and a spiral flue
+leading outward to the chimney. Another somewhat larger machine was
+built and placed beside this engine, some time previous to 1775. Its
+cylinder was 49 inches in diameter, and its stroke 9 feet. It raised
+water 102 feet. This engine was altered and improved by Smeaton in
+1777, and continued in use until 1813.
+
+Smeaton, as early as 1765, designed a _portable_ engine,[33] in which
+he supported the machinery on a wooden frame mounted on short legs and
+strongly put together, so that the whole machine could be transported
+and set at work wherever convenient.
+
+  [33] Smeaton's "Reports," vol. i., p. 223.
+
+[Illustration: FIG. 23.--Smeaton's Portable-Engine Boiler, 1765.]
+
+In place of the beam, a large pulley was used, over which a chain was
+carried, connecting the piston with the pump-rod, and the motion was
+similar to that given by the discarded beam. The wheel was supported
+on A-frames, resembling somewhat the "gallows-frames" still used with
+the beam-engines of American river-boats. The sills carrying the two
+A's supported the cylinder. The injection-cistern was supported above
+the great pulley-wheel. The valve-gearing and the injection-pump were
+worked by a smaller wheel, mounted on the same axis with the larger
+one. The boiler was placed apart from the engine, with which it was
+connected by a steam-pipe, in which was placed the "regulator," or
+throttle-valve. The boiler (Fig. 23) "was shaped like a large
+tea-kettle," and contained a fire-box, _B_, or internal furnace, of
+which the sides were made of cast-iron. The fire-door, _C_, was placed
+on one side and opposite the flue, _D_, through which the products of
+combustion were led to the chimney, _E_; a short, large pipe, _F_,
+leading downward from the furnace to the outside of the boiler, was
+the ash-pit. The shell of the boiler, _A_, was made of iron plate
+one-quarter of an inch thick. The steam-cylinder of the engine was 18
+inches in diameter, the stroke of piston 6 feet, the great wheel 6-1/2
+feet in diameter, and the A-frames 9 feet high. The boiler was made 6
+feet, the furnace 34 inches, and the grate 18 inches in diameter. The
+piston was intended to make 10 strokes per minute, and the engine to
+develop 4-1/8 horse-power.
+
+In 1773, Smeaton prepared plans for a pumping-engine to be set up at
+Cronstadt, the port of St. Petersburg, to empty the great dry dock
+constructed by Peter the Great and Catherine, his successor. This
+great dock was begun in 1719. It was large enough to dock ten of the
+ships of that time, and had previously been imperfectly drained by two
+great windmills 100 feet high. So imperfectly did they do their work,
+that a _year_ was required to empty the dock, and it could therefore
+only be used once in each summer. The engine was built at the Carron
+Iron Works, in England. It had a cylinder 66 inches in diameter, and a
+stroke of piston of 8-1/2 feet. The lift varied from 33 feet when the
+dock was full to 53 feet when it was cleared of water. The load on the
+engine averaged about 8-1/3 pounds per square inch of piston-area.
+There were three boilers, each 10 feet in diameter, and 16 feet 4
+inches high to the apex of its hemispherical dome. They contained
+internal fire-boxes with grates of 20 feet area, and were surrounded
+by flues helically traversing the masonry setting. The engine was
+started in 1777, and worked very successfully.
+
+The lowlands of Holland were, before the time of Smeaton, drained by
+means of windmills. The uncertainty and inefficiency of this method
+precluded its application to anything like the extent to which
+steam-power has since been utilized. In 1440, there were 150 inland
+lakes, or "_meers_," in that country, of which nearly 100, having an
+extent of over 200,000 acres, have since been drained. The "Haarlemmer
+Meer" alone covers nearly 50,000 acres, and forms the basin of a
+drainage-area of between 200,000 and 300,000 acres, receiving a
+rainfall of 54,000,000 tons, which must be raised 16 feet in
+discharging it. The beds of these lakes are from 10 to 20 feet lower
+than the water-level in the adjacent canals. In 1840, 12,000 windmills
+were still employed in this work. In the following year, William II.,
+at the suggestion of a commission, decreed that only steam-engines
+should be employed to do this immense work. Up to this time the
+average consumption of fuel for the pumping-engines in use is said to
+have been 20 pounds per hour per horse-power.
+
+The first engine used was erected in 1777 and 1778, on the Newcomen
+plan, to assist the 34 windmills employed to drain a lake near
+Rotterdam. This lake covered 7,000 acres, and its bed was 12 feet
+below the surface of the river Meuse, which passes it, and empties
+into the sea in the immediate neighborhood. The iron parts of the
+engine were built in England, and the machine was put together in
+Holland. The steam-cylinder was 52 inches in diameter, and the stroke
+of piston 9 feet. The boiler was 18 feet in diameter, and contained a
+double flue. The main beam was 27 feet long. The pumps were 6 in
+number, 3 cylindrical and 3 having a square cross-section; 3 were of 6
+feet and 3 of 2-1/2 feet stroke. Two pumps only were worked at
+high-tide, and the others were added one at a time, as the tide fell,
+until, at low-tide, all 6 were at work.
+
+The size of this engine, and the magnitude of its work, seem
+insignificant when compared with the machinery installed 60 years
+later to drain the Haarlemmer Meer, and with the work done by the
+last. These engines are 12 feet in diameter of cylinder and 10 feet
+stroke of piston, and work--they are 3 in number--the one 11 pumps of
+63 inches diameter and 10 feet stroke, the others 8 pumps of 73 inches
+diameter and of the same length of stroke. The modern engines do a
+"duty" of 75,000,000 to 87,000,000 with 94 pounds of coal, consuming
+2-1/4 pounds of coal per hour and per horse-power.
+
+The first steam-engine applied to working the blowing-machinery of a
+blast-furnace was erected at the Carron Iron-Works, in Scotland, near
+Falkirk, in 1765, and proved very unsatisfactory. Smeaton
+subsequently, in 1769 or 1770, introduced better machinery into these
+works and improved the old engine, and this use of the steam-engine
+soon became usual. This engine did its work indirectly, furnishing
+water, by pumping, to drive the water-wheels which worked the
+blowing-cylinders. Its steam-cylinder was 6 feet in diameter, and the
+pump-cylinder 52 inches. The stroke was 9 feet.
+
+A direct-acting engine, used as a blowing-engine, was not constructed
+until about 1784, at which time a single-acting blowing-cylinder, or
+air-pump, was placed at the "out-board" end of the beam, where the
+pump-rod had been attached. The piston of the air-cylinder was loaded
+with the weights needed to force it down, expelling the air, and the
+engine did its work in raising the loaded piston, the air-cylinder
+filling as the piston rose. A large "accumulator" was used to equalize
+the pressure of the expelled air. This consisted of another
+air-cylinder, having a loaded piston which was left free to rise and
+fall. At each expulsion of air by the blowing-engine this cylinder was
+filled, the loaded piston rising to the top. While the piston of the
+former was returning, and the air-cylinder was taking in its charge of
+air, the accumulator would gradually discharge the stored air, the
+piston slowly falling under its load. This piston was called the
+"floating piston," or "fly-piston," and its action was, in effect,
+precisely that of the upper portion of the common blacksmith's
+bellows.
+
+Dr. Robison, the author of "Mechanical Philosophy," one of the very
+few works even now existing deserving such a title, describes one of
+these engines[34] as working in Scotland in 1790. It had a
+steam-cylinder 40 or 44 inches in diameter, a blowing-cylinder 60
+inches in diameter, and the stroke of piston was 6 feet. The
+air-pressure was 2.77 pounds per square inch as a maximum in the
+blowing-cylinder; and the floating piston in the regulating-cylinder
+was loaded with 2.63 pounds per square inch. Making 15 or 18 strokes
+per minute, this engine delivered about 1,600 cubic feet of air, or
+120-1/2 pounds in weight, per minute, and developed 20 horse-power.
+
+  [34] "Encyclopædia Britannica," 1st edition.
+
+At about the same date a change was made in the blowing-cylinder. The
+air entered at the bottom, as before, but was forced out at the top,
+the piston being fitted with valves, as in the common lifting-pump,
+and the engine thus being arranged to do the work of expulsion during
+the down-stroke of the steam-piston.
+
+Four years later, the regulating-cylinder, or accumulator, was given
+up, and the now familiar "water-regulator" was substituted for it.
+This consists of a tank, usually of sheet-iron, set open-end downward
+in a large vessel containing water. The lower edge of the inner tank
+is supported on piers a few inches above the bottom of the large one.
+The pipe carrying air from the blowing-engine passes above this
+water-regulator, and a branch-pipe is led down into the inner tank. As
+the air-pressure varies, the level of the water within the inverted
+tank changes, rising as pressure falls at the slowing of the motion of
+the piston, and falling as the pressure rises again while the piston
+is moving with an accelerated velocity. The regulator, thus receiving
+surplus air to be delivered when needed, greatly assists in regulating
+the pressure. The larger the regulator, the more perfectly uniform the
+pressure. The water-level outside the inner tank is usually five or
+six feet higher than within it. This apparatus was found much more
+satisfactory than the previously-used regulator, and, with its
+introduction, the establishment of the steam-engine as a
+blowing-engine for iron-works and at blast-furnaces may be considered
+as having been fully established.
+
+Thus, by the end of the third quarter of the eighteenth century, the
+steam-engine had become generally introduced, and had been applied to
+nearly all of the purposes for which a single-acting engine could be
+used. The path which had been opened by Worcester had been fairly laid
+out by Savery and his contemporaries, and the builders of the Newcomen
+engine, with such improvements as they had been able to effect, had
+followed it as far as they were able. The real and practical
+introduction of the steam-engine is as fairly attributable to Smeaton
+as to any one of the inventors whose names are more generally known in
+connection with it. As a mechanic, he was unrivaled; as an engineer,
+he was head and shoulders above any constructor of his time engaged in
+general practice. There were very few important public works built in
+Great Britain at that time in relation to which he was not consulted;
+and he was often visited by foreign engineers, who desired his advice
+with regard to works in progress on the Continent.
+
+[Illustration]
+
+
+
+
+CHAPTER III.
+
+_THE DEVELOPMENT OF THE MODERN STEAM-ENGINE. JAMES WATT AND HIS
+CONTEMPORARIES._
+
+  The world is now entering upon the Mechanical Epoch. There is
+  nothing in the future more sure than the great triumphs which that
+  epoch is to achieve. It has already advanced to some glorious
+  conquests. What miracles of invention now crowd upon us! Look
+  abroad, and contemplate the infinite achievements of the
+  steam-power.
+
+  And yet we have only begun--we are but on the threshold of this
+  epoch.... What is it but the setting of the great distinctive seal
+  upon the nineteenth century?--an advertisement of the fact that
+  society has risen to occupy a higher platform than ever before?--a
+  proclamation from the high places, announcing honor, honor immortal,
+  to the workmen who fill this world with beauty, comfort, and
+  power--honor to be forever embalmed in history, to be perpetuated in
+  monuments, to be written in the hearts of this and succeeding
+  generations!--KENNEDY.
+
+
+SECTION I.--JAMES WATT AND HIS INVENTIONS.
+
+The success of the Newcomen engine naturally attracted the attention
+of mechanics, and of scientific men as well, to the possibility of
+making other applications of steam-power.
+
+The best men of the time gave much attention to the subject, but,
+until James Watt began the work that has made him famous, nothing more
+was done than to improve the proportions and slightly alter the
+details of the Newcomen and Calley engine, even by such skillful
+engineers as Brindley and Smeaton. Of the personal history of the
+earlier inventors and improvers of the steam-engine, very little is
+ascertained; but that of Watt has become well known.
+
+[Illustration: James Watt.]
+
+JAMES WATT was of an humble lineage, and was born at Greenock, then a
+little Scotch fishing village, but now a considerable and a busy town,
+which annually launches upon the waters of the Clyde a fleet of
+steamships whose engines are probably, in the aggregate, far more
+powerful than were all the engines in the world at the date of Watt's
+birth, January 19, 1736. His grandfather, Thomas Watt, of
+Crawfordsdyke, near Greenock, was a well-known mathematician about the
+year 1700, and was for many years a schoolmaster at that place. His
+father was a prominent citizen of Greenock, and was at various times
+chief magistrate and treasurer of the town. James Watt was a bright
+boy, but exceedingly delicate in health, and quite unable to attend
+school regularly, or to apply himself closely to either study or play.
+His early education was given by his parents, who were respectable and
+intelligent people, and the tools borrowed from his father's
+carpenter-bench served at once to amuse him and to give him a
+dexterity and familiarity with their use that must undoubtedly have
+been of inestimable value to him in after-life.
+
+M. Arago, the eminent French philosopher, who wrote one of the
+earliest and most interesting biographies of Watt, relates anecdotes
+of him which, if correct, illustrate well his thoughtfulness and his
+intelligence, as well as the mechanical bent of the boy's mind. He is
+said, at the age of six years, to have occupied himself during leisure
+hours with the solution of geometrical problems; and Arago discovers,
+in a story in which he is described as experimenting with the
+tea-kettle,[35] his earliest investigations of the nature and
+properties of steam.
+
+  [35] The same story is told of Savery and of Worcester.
+
+When finally sent to the village school, his ill health prevented his
+making rapid progress; and it was only when thirteen or fourteen years
+of age that he began to show that he was capable of taking the lead in
+his class, and to exhibit his ability in the study, particularly, of
+mathematics. His spare time was principally spent in sketching with
+his pencil, in carving, and in working at the bench, both in wood and
+metal. He made many ingenious pieces of mechanism, and some beautiful
+models. His favorite work seemed to be the repairing of nautical
+instruments. Among other pieces of apparatus made by the boy was a
+very fine barrel-organ. In boyhood, as in after-life, he was a
+diligent reader, and seemed to find something to interest him in every
+book that came into his hands.
+
+At the age of eighteen, Watt was sent to Glasgow, there to
+reside with his mother's relatives, and to learn the trade of a
+mathematical-instrument maker. The mechanic with whom he was placed
+was soon found too indolent, or was otherwise incapable of giving
+much aid in the project, and Dr. Dick, of the University of Glasgow,
+with whom Watt became acquainted, advised him to go to London.
+Accordingly, he set out in June, 1755, for the metropolis, where, on
+his arrival, he arranged with Mr. John Morgan, in Cornhill, to work a
+year at his chosen business, receiving as compensation 20 guineas. At
+the end of the year he was compelled, by serious ill-health, to return
+home.
+
+Having become restored to health, he went again to Glasgow in 1756,
+with the intention of pursuing his calling there. But, not being the
+son of a burgess, and not having served his apprenticeship in the
+town, he was forbidden by the guilds, or trades-unions, to open a shop
+in Glasgow. Dr. Dick came to his aid, and employed him to repair some
+apparatus which had been bequeathed to the college. He was finally
+allowed the use of three rooms in the University building, its
+authorities not being under the municipal rule. He remained here until
+1760, when, the trades no longer objecting, he took a shop in the
+city; and in 1761 moved again, into a shop on the north side of the
+Trongate, where he earned a scanty living without molestation, and
+still kept up his connection with the college. He did some work as a
+civil engineer in the neighborhood of Glasgow, but soon gave up all
+other employment, and devoted himself entirely to mechanics.
+
+He spent much of his leisure time--of which he had, at first, more
+than was desirable--in making philosophical experiments and in the
+manufacture of musical instruments, in making himself familiar with
+the sciences, and in devising improvements in the construction of
+organs. In order to pursue his researches more satisfactorily, he
+studied German and Italian, and read Smith's "Harmonics," that he
+might become familiar with the principles of construction of musical
+instruments. His reading was still very desultory; but the
+introduction of the Newcomen engine in the neighborhood of Glasgow,
+and the presence of a model in the college collections, which was
+placed in his hands, in 1763, for repair, led him to study the history
+of the steam-engine, and to conduct for himself an experimental
+research into the properties of steam, with a set of improvised
+apparatus.
+
+Dr. Robison, then a student of the University, who found Watt's shop a
+pleasant place in which to spend his leisure, and whose tastes
+affiliated so strongly with those of Watt that they became friends
+immediately upon making acquaintance, called the attention of the
+instrument-maker to the steam-engine as early as 1759, and suggested
+that it might be applied to the propulsion of carriages. Watt was at
+once interested, and went to work on a little model, having tin
+steam-cylinders and pistons connected to the driving-wheels by an
+intermediate system of gearing. The scheme was afterwards given up,
+and was not revived by Watt for a quarter of a century.
+
+Watt studied chemistry, and was assisted by the advice and instruction
+of Dr. Black, who was then making the researches which resulted in the
+discovery of "latent heat." His proposal to repair the model Newcomen
+engine in the college collections led to his study of Desaguliers's
+treatise, and of the works of Switzer and others. He thus learned what
+had been done by Savery and by Newcomen, and by those who had improved
+the engine of the latter.
+
+In his own experiments he used, at first, apothecaries' phials and
+hollow canes for steam reservoirs and pipes, and later a Papin's
+digester and a common syringe. The latter combination made a
+non-condensing engine, in which he used steam at a pressure of 15
+pounds per square inch. The valve was worked by hand, and Watt saw
+that an automatic valve-gear only was needed to make a working
+machine. This experiment, however, led to no practical result. He
+finally took hold of the Newcomen model, which had been obtained from
+London, where it had been sent for repairs, and, putting it in good
+working order, commenced experiments with that.
+
+The Newcomen model, as it happened, had a boiler which, although made
+to a scale from engines in actual use, was quite incapable of
+furnishing steam enough to work the engine. It was about nine inches
+in diameter; the steam-cylinder was two inches in diameter, and of six
+inches stroke of piston, arranged as in Fig. 24, which is a picture of
+the model as it now appears. It is retained among the most
+carefully-preserved treasures of the University of Glasgow.
+
+[Illustration: FIG. 24.--The Newcomen Model.]
+
+Watt made a new boiler for the experimental investigation on which he
+was about to enter, and arranged it in such a manner that he could
+measure the quantity of water evaporated and of steam used at every
+stroke of the engine.
+
+He soon discovered that it required but a very small quantity of steam
+to heat a very large quantity of water, and immediately attempted to
+determine with precision the relative weights of steam and water in
+the steam-cylinder when condensation took place at the down-stroke of
+the engine, and thus independently proved the existence of that
+"latent heat," the discovery of which constitutes, also, one of the
+greatest of Dr. Black's claims to distinction. Watt at once went to
+Dr. Black and related the remarkable fact which he had thus detected,
+and was, in turn, taught by Black the character of the phenomenon as
+it had been explained to his classes by the latter some little time
+previously. Watt found that, at the boiling-point, his steam,
+condensing, was capable of heating six times its weight of water such
+as was used for producing condensation.
+
+Perceiving that steam, weight for weight even, was a vastly greater
+absorbent and reservoir of heat than water, Watt saw plainly the
+importance of taking greater care to economize it than had previously
+been customary. He first attempted to economize in the boiler, and
+made boilers with wooden "shells," in order to prevent losses by
+conduction and radiation, and used a larger number of flues to secure
+more complete absorption of the heat from the furnace-gases. He also
+covered his steam-pipes with non-conducting materials, and took every
+precaution that his ingenuity could devise to secure complete
+utilization of the heat of combustion. He soon found, however, that he
+was not working at the most important point, and that the great source
+of loss was to be found in defects which he noted in the action of the
+steam in the cylinder. He soon concluded that the sources of loss of
+heat in the Newcomen engine--which would be greatly exaggerated in a
+small model--were:
+
+First, the dissipation of heat by the cylinder itself, which was of
+brass, and was both a good conductor and a good radiator.
+
+Secondly, the loss of heat consequent upon the necessity of cooling
+down the cylinder at every stroke, in producing the vacuum.
+
+Thirdly, the loss of power due to the pressure of vapor beneath the
+piston, which was a consequence of the imperfect method of
+condensation.
+
+He first made a cylinder of non-conducting material--wood soaked in
+oil and then baked--and obtained a decided advantage in economy of
+steam. He then conducted a series of very accurate experiments upon
+the temperature and pressure of steam at such points on the scale as
+he could readily reach, and, constructing a curve with his results,
+the abscesses representing temperatures and the pressures being
+represented by the ordinates, he ran the curve backward until he had
+obtained closely-approximate measures of temperatures less than 212°,
+and pressures less than atmospheric. He thus found that, with the
+amount of injection-water used in the Newcomen engine, bringing the
+temperature of the interior, as he found, down to from 140° to 175°
+Fahr., a very considerable back-pressure would be met with.
+
+Continuing his examination still further, he measured the amount of
+steam used at each stroke, and, comparing it with the quantity that
+would just fill the cylinder, he found that at least _three-fourths
+was wasted_. The quantity of cold water necessary to produce the
+condensation of a given weight of steam was next determined; and he
+found that one pound of steam contained enough heat to raise about six
+pounds of cold water, as used for condensation, from the temperature
+of 52° to the boiling-point; and, going still further, he found that
+he was compelled to use, at each stroke of the Newcomen engine, _four
+times as much injection-water as should suffice to condense a cylinder
+full of steam_. This confirmed his previous conclusion that
+three-fourths of the heat supplied to the engine was wasted.
+
+Watt had now, therefore, determined by his own researches, as he
+himself enumerates them,[36] the following facts:
+
+  [36] Robison's "Mechanical Philosophy," edited by Brewster.
+
+"1. The capacities for heat of iron, copper, and of some sorts of
+wood, as compared with water.
+
+"2. The bulk of steam compared with that of water.
+
+"3. The quantity of water evaporated in a certain boiler by a pound of
+coal.
+
+"4. The elasticities of steam at various temperatures greater than
+that of boiling water, and an approximation to the law which it
+follows at other temperatures.
+
+"5. How much water in the form of steam was required every stroke by a
+small Newcomen engine, with a wooden cylinder 6 inches in diameter and
+12 inches stroke.
+
+"6. The quantity of cold water required in every stroke to condense
+the steam in that cylinder, so as to give it a working-power of about
+7 pounds on the square inch."
+
+After these well-devised and truly scientific investigations, Watt was
+enabled to enter upon his work of improving the steam-engine with an
+intelligent understanding of its existing defects, and with a
+knowledge of their cause. Watt soon saw that, in order to reduce the
+losses in the working of the steam in the steam-cylinder, it would be
+necessary to find some means, as he said, to keep the cylinder "always
+as hot as the steam that entered it," notwithstanding the great
+fluctuations of temperature and pressure of the steam during the up
+and the down strokes. He has told us how, finally, the happy thought
+occurred to him which relieved him of all difficulty, and led to the
+series of modifications which at last gave to the world the modern
+type of steam-engine.
+
+He says:[37] "I had gone to take a walk on a fine Sabbath afternoon. I
+had entered the Green by the gate at the foot of Charlotte street, and
+had passed the old washing-house. I was thinking upon the engine at
+the time, and had gone as far as the herd's house, when the idea came
+into my mind that, as steam was an elastic body, it would rush into a
+vacuum, and, if a communication were made between the cylinder and an
+exhausted vessel, it would rush into it, and might be there condensed
+without cooling the cylinder. I then saw that I must get rid of the
+condensed steam and injection-water if I used a jet, as in Newcomen's
+engine. Two ways of doing this occurred to me: First, the water might
+be run off by a descending pipe, if an offlet could be got at the
+depth of 35 or 36 feet, and any air might be extracted by a small
+pump. The second was, to make the pump large enough to extract both
+water and air." "I had not walked farther than the Golf-house, when
+the whole thing was arranged in my mind."
+
+  [37] "Reminiscences of James Watt," Robert Hart; "Transactions of
+  the Glasgow Archæological Society," 1859.
+
+Referring to this invention, Watt said to Prof. Jardine:[38] "When
+analyzed, the invention would not appear so great as it seemed to be.
+In the state in which I found the steam-engine, it was no great effort
+of mind to observe that the quantity of fuel necessary to make it work
+would forever prevent its extensive utility. The next step in my
+progress was equally easy--to inquire what was the cause of the great
+consumption of fuel. This, too, was readily suggested, viz., the waste
+of fuel which was necessary to bring the whole cylinder, piston, and
+adjacent parts from the coldness of water to the heat of steam, no
+fewer than from 15 to 20 times in a minute." It was by pursuing this
+train of thought that he was led to devise the separate condenser.
+
+  [38] "Lives of Boulton and Watt," Smiles.
+
+On Monday morning Watt proceeded to make an experimental test of his
+new invention, using for his steam-cylinder and piston a large brass
+surgeon's-syringe, 1-3/4-inch diameter and 10 inches long. At each end
+was a pipe leading steam from the boiler, and fitted with a cock to
+act as a steam-valve. A pipe led also from the top of the cylinder to
+the condenser, the syringe being inverted and the piston-rod hanging
+downward for convenience. The condenser was made of two pipes of thin
+tin plate, 10 or 12 inches long, and about one-sixth of an inch in
+diameter, standing vertically, and having a connection at the top
+with a horizontal pipe of larger size, and fitted with a
+"snifting-valve." Another vertical pipe, about an inch in diameter,
+was connected to the condenser, and was fitted with a piston, with a
+view to using it as an "air-pump." The whole was set in a cistern of
+cold water. The piston-rod of the little steam-cylinder was drilled
+from end to end to permit the water to be removed from the cylinder.
+This little model (Fig. 25) worked very satisfactorily, and the
+perfection of the vacuum was such that the machine lifted a weight of
+18 pounds hung upon the piston-rod, as in the sketch. A larger model
+was immediately afterward constructed, and the result of its test
+confirmed fully the anticipations which had been awakened by the first
+experiment.
+
+[Illustration: FIG. 25.--Watt's Experiment.]
+
+Having taken this first step and made such a radical improvement, the
+success of this invention was no sooner determined than others
+followed in rapid succession, as consequences of the exigencies
+arising from the first change in the old Newcomen engine. But in the
+working out of the forms and proportions of the details of the new
+engine, even Watt's powerful mind, stored as it was with
+happily-combined scientific and practical information, was occupied
+for years. In attaching the separate condenser, he first attempted
+surface-condensation; but this not succeeding well, he substituted the
+jet. Some provision became at once necessary for preventing the
+filling of the condenser with water.
+
+Watt at first intended adopting the expedient which had worked
+satisfactorily with the less effective condensation of Newcomen's
+engine--i. e., leading a pipe from the condenser to a depth greater
+than the height of a column of water which could be counterbalanced by
+the pressure of the atmosphere; but he subsequently employed the
+air-pump, which relieves the condenser not only of the water, but of
+the air which also usually collects in considerable volume in the
+condenser, and vitiates the vacuum. He next substituted oil and tallow
+for water in the lubrication of the piston and keeping it steam-tight,
+in order to avoid the cooling of the cylinder incident to the use of
+the latter. Another cause of refrigeration of the cylinder, and
+consequent waste of power in its operation, was seen to be the
+entrance of the atmosphere, which followed the piston down the
+cylinder at each stroke, cooling its interior by its contact. This the
+inventor concluded to prevent by covering the top of the cylinder,
+allowing the piston-rod to play through a "stuffing-box"--which device
+had long been known to mechanics.
+
+He accordingly not only covered the top, but surrounded the whole
+cylinder with an external casing, or "steam-jacket," and allowed the
+steam from the boiler to pass around the steam-cylinder and to press
+upon the upper surface of the piston, where its pressure was variable
+at pleasure, and therefore more manageable than that of the
+atmosphere. It also, besides keeping the cylinder hot, could do
+comparatively little harm should it leak by the piston, as it could be
+condensed, and thus readily disposed of.
+
+When he had concluded to build the larger experimental engine, Watt
+determined to give his whole time and attention to the work, and hired
+a room in an old deserted pottery near the Broomielaw. Here he worked
+with a mechanic--John Gardiner, whom he had taken into his
+employ--uninterruptedly for many weeks. Meantime, through his friend
+Dr. Black, probably, he had made the acquaintance of Dr. Roebuck, a
+wealthy physician, who had, with other Scotch capitalists, just
+founded the celebrated Carron Iron-Works, and had opened a
+correspondence with him, in which he kept that gentleman informed of
+the progress of his work on the new engine.
+
+This engine had a steam-cylinder, Watt tells us, of "five or six"
+inches diameter, and of two feet stroke. It was of copper,
+smooth-hammered, but not bored out, and "not very true." This was
+encased in another cylinder of wood. In August, 1765, he tried the
+small engine, and wrote Dr. Roebuck that he had had "good success,"
+although the machine was very imperfect. "On turning the
+exhausting-cock, the piston, when not loaded, ascended as quick as the
+blow of a hammer, and as quick when loaded with 18 pounds (being 7
+pounds on the inch) as it would have done if it had had an injection
+as usual." He then tells his correspondent that he was about to make
+the larger model. In October, 1765, he finished the latter. The
+engine, when ready for trial, was still very imperfect. It
+nevertheless did good work for so rude a machine.
+
+Watt was now reduced to poverty, and, after borrowing considerable
+sums from friends, he was finally compelled to give up his scheme for
+the time, and to seek employment in order to provide for his family.
+During an interval of about two years he supported himself by
+surveying, and by the work of exploring coal-fields in the
+neighborhood of Glasgow for the magistrates of the city. He did not,
+however, entirely give up his invention.
+
+In 1767, Dr. Roebuck assumed Watt's liabilities to the amount of
+£1,000, and agreed to provide capital for the prosecution of his
+experiments and to introduce his invention; and, on the other hand,
+Watt agreed to surrender to Dr. Roebuck two-thirds of the patent.
+Another engine was next built, having a steam-cylinder seven or eight
+inches in diameter, which was finished in 1768. This worked
+sufficiently well to induce the partners to ask for a patent, and the
+specifications and drawings were completed and presented in 1769.
+
+Watt also built and set up several Newcomen engines, partly, perhaps,
+to make himself thus thoroughly familiar with the practical details of
+engine-building. Meantime, also, he prepared the plans for, and
+finally had built, a moderately large engine of his own new type. Its
+steam-cylinder was 18 inches in diameter, and the stroke of piston was
+5 feet. This engine was built at Kinneil, and was finished in
+September, 1769. It was not all satisfactory in either its
+construction or its operation. The condenser was a surface-condenser
+composed of pipes somewhat like that used in his first little model,
+and did not prove to be satisfactorily tight. The steam-piston leaked
+seriously, and repeated trials only served to make more evident its
+imperfections. He was assisted in this time of need by both Dr. Black
+and Dr. Roebuck; but he felt strongly the risks which he ran of
+involving his friends in serious losses, and became very despondent.
+Writing to Dr. Black, he says: "Of all things in life, there is
+nothing more foolish than inventing;" and probably the majority of
+inventors have been led to the same opinion by their own experiences.
+
+"Misfortunes never come singly;" and Watt was borne down by the
+greatest of all misfortunes--the loss of a faithful and affectionate
+wife--while still unable to see a successful issue of his schemes.
+Only less disheartening than this was the loss of fortune of his
+steadfast friend, Dr. Roebuck, and the consequent loss of his aid. It
+was at about this time, in the year 1769, that negotiations were
+commenced which resulted in the transfer of the capitalized interest
+in Watt's engine to the wealthy manufacturer whose name, coupled with
+that of Watt, afterward became known throughout the civilized world,
+as the steam-engine in its new form was pushed into use by his energy
+and business tact.
+
+Watt met Mr. Boulton, who next became his partner, in 1768, on his
+journey to London to procure his patent, and the latter had then
+examined Watt's designs, and, at once perceiving their value, proposed
+to purchase an interest. Watt was then unable to reply definitely to
+Boulton's proposition, pending his business arrangements with Dr.
+Roebuck; but, with Roebuck's consent, afterwards proposed that Boulton
+should take a one-third interest with himself and partner, paying
+Roebuck therefor one-half of all expenses previously incurred, and
+whatever he should choose to add to compensate "for the risk he had
+run." Subsequently, Dr. Roebuck proposed to transfer to Boulton and to
+Dr. Small, who was desirous of taking interest with Boulton, one-half
+of his proprietorship in Watt's inventions, on receiving "a sum not
+less than one thousand pounds," which should, after the experiments on
+the engine were completed, be deemed "just and reasonable." Twelve
+months were allowed for the adjustment of the account. This proposal
+was accepted in November, 1769.
+
+[Illustration: Matthew Boulton.]
+
+MATTHEW BOULTON, who now became a partner with James Watt, was the son
+of a Birmingham silver stamper and piecer, and succeeded to his
+father's business, building up a great establishment, which, as well
+as its proprietor, was well known in Watt's time. Watt, writing to Dr.
+Roebuck before the final arrangement had been made, urged him to close
+with Boulton for "the following considerations:
+
+"1st. From Mr. Boulton's own character as an ingenious, honest, and
+rich man. 2dly. From the difficulty and expense there would be of
+procuring accurate and honest workmen and providing them with proper
+utensils, and getting a proper overseer or overseers. If, to avoid
+this inconvenience, you were to contract for the work to be done by a
+master-workman, you must give up a great share of the profit. 3dly.
+The success of the engine is far from being verified. If Mr. Boulton
+takes his chance of success from the account I shall write Dr. Small,
+and pays you any adequate share of the money laid out, it lessens your
+risk, and in a greater proportion than I think it will lessen your
+profits. 4thly. The assistance of Mr. Boulton's and Dr. Small's
+ingenuity (if the latter engage in it) in improving and perfecting the
+machine may be very considerable, and may enable us to get the better
+of the difficulties that might otherwise damn it. Lastly, consider my
+uncertain health, my irresolute and inactive disposition, my inability
+to bargain and struggle for my own with mankind: all which disqualify
+me for any great undertaking. On our side, consider the first outlay
+and interest, the patent, the present engine, about £200 (though there
+would not be much loss in making it into a common engine), two years
+of my time, and the expense of models."
+
+Watt's estimate of the value of Boulton's ingenuity and talent was
+well-founded. Boulton had shown himself a good scholar, and had
+acquired considerable knowledge of the languages and of the sciences,
+particularly of mathematics, after leaving the school from which he
+graduated into the shop when still a boy. In the shop he soon
+introduced a number of valuable improvements, and he was always on the
+lookout for improvements made by others, with a view to their
+introduction in his business. He was a man of the modern style, and
+never permitted competitors to excel him in any respect, without the
+strongest efforts to retain his leading position. He always aimed to
+earn a reputation for good work, as well as to make money. His
+father's workshop was at Birmingham; but Boulton, after a time, found
+that his rapidly-increasing business would compel him to find room for
+the erection of a more extensive establishment, and he secured land at
+Soho, two miles distant from Birmingham, and there erected his new
+manufactory, about 1762.
+
+The business was, at first, the manufacture of ornamental metal-ware,
+such as metal buttons, buckles, watch-chains, and light filigree and
+inlaid work. The manufacture of gold and silver plated-ware was soon
+added, and this branch of business gradually developed into a very
+extensive manufacture of works of art. Boulton copied fine work
+wherever he could find it, and often borrowed vases, statuettes, and
+bronzes of all kinds from the nobility of England, and even from the
+queen, from which to make copies. The manufacture of inexpensive
+clocks, such as are now well known throughout the world as an article
+of American trade, was begun by Boulton. He made some fine
+astronomical and valuable ornamental clocks, which were better
+appreciated on the Continent than in England. The business of the Soho
+manufactory in a few years became so extensive, that its goods were
+known to every civilized nation, and its growth, under the management
+of the enterprising, conscientious, and ingenious Boulton, more than
+kept pace with the accumulation of capital; and the proprietor found
+himself, by his very prosperity, often driven to the most careful
+manipulation of his assets, and to making free use of his credit.
+
+Boulton had a remarkable talent for making valuable acquaintances, and
+for making the most of advantages accruing thereby. In 1758 he made
+the acquaintance of Benjamin Franklin, who then visited Soho; and in
+1766 these distinguished men, who were then unaware of the existence
+of James Watt, were corresponding, and, in their letters, discussing
+the applicability of steam-power to various useful purposes. Between
+the two a new steam-engine was designed, and a model was constructed
+by Boulton, which was sent to Franklin and exhibited by him in London.
+
+Dr. Darwin seems to have had something to do with this scheme, and the
+enthusiasm awakened by the promise of success given by this model may
+have been the origin of the now celebrated prophetic rhymes so often
+quoted from the works of that eccentric physician and poet. Franklin
+contributed, as his share in the plan, an idea of so arranging the
+grate as to prevent the production of smoke. He says: "All that is
+necessary is to make the smoke of fresh coals pass descending through
+those that are already ignited." His idea has been, by more recent
+schemers, repeatedly brought forward as new. Nothing resulted from
+these experiments of Boulton, Franklin, and Darwin, and the plan of
+Watt soon superseded all less well-developed plans.
+
+In 1767, Watt visited Soho and carefully inspected Boulton's
+establishment. He was very favorably impressed by the admirable
+arrangement of the workshops and the completeness of their outfit, as
+well as by the perfection of the organization and administration of
+the business. In the following year he again visited Soho, and this
+time met Boulton, who had been absent at the previous visit. The two
+great mechanics were mutually gratified by the meeting, and each at
+once acquired for the other the greatest respect and esteem. They
+discussed Watt's plans, and Boulton then definitely decided not to
+continue his own experiments, although he had actually commenced the
+construction of a pumping-engine. With Dr. Small, who was also at
+Soho, Watt discussed the possibility of applying his engine to the
+propulsion of carriages, and to other purposes. On his return home,
+Watt continued his desultory labors on his engines, as already
+described; and the final completion of the arrangement with Boulton,
+which immediately followed the failure of Dr. Roebuck, took place some
+time later.
+
+Before Watt could leave Scotland to join his partner at Soho, it was
+necessary that he should finish the work which he had in hand,
+including the surveys of the Caledonian canal, and other smaller
+works, which he had had in progress some months. He reached Birmingham
+in the spring of 1774, and was at once domiciled at Soho, where he set
+at work upon the partly-made engines which had been sent from Scotland
+some time previously. They had laid, unused and exposed to the
+weather, at Kinneil three years, and were not in as good order as
+might have been desired. The _block-tin_ steam-cylinder was probably
+in good condition, but the iron parts were, as Watt said, "perishing,"
+while he had been engaged in his civil engineering work. At leisure
+moments, during this period, Watt had not entirely neglected his plans
+for the utilization of steam. He had given much thought, and had
+expended some time, in experiments upon the plan of using it in a
+rotary or "wheel" engine. He did not succeed in contriving any plan
+which seemed to promise success.
+
+It was in November, 1774, that Watt finally announced to his old
+partner, Dr. Roebuck, the successful trial of the Kinneil engine. He
+did not write with the usual enthusiasm and extravagance of the
+inventor, for his frequent disappointments and prolonged suspense had
+very thoroughly extinguished his vivacity. He simply wrote: "The
+fire-engine I have invented is now going, and answers much better than
+any other that has yet been made; and I expect that the invention will
+be very beneficial to me."
+
+The change of the "atmospheric engine" of Newcomen into the modern
+steam-engine was now completed in its essential details. The first
+engine which was erected at Kinneil, near Boroughstoness, had a
+steam-cylinder 18 inches in diameter. It is seen in the accompanying
+sketch.
+
+[Illustration: FIG. 26.--Watt's Engine, 1774.]
+
+In Fig. 26, the steam passes from the boiler through the pipe _d_ and
+the valve _c_ to the cylinder-casing or steam-jacket, _Y Y_, and above
+the piston, _b_, which it follows in its descent in the cylinder,
+_a_, the valve _f_ being at this time open, to allow the exhaust into
+the condenser, _h_.
+
+The piston now being at the lower end of the cylinder, and the
+pump-rods at the opposite end of the beam, _y_, being thus raised and
+the pumps filled with water, the valves _c_ and _f_ close, while _e_
+opens, allowing the steam which remains above the piston to flow
+beneath it, until, the pressures becoming equal above and below, the
+weight of the pump-rods overbalancing that of the piston, the latter
+is rapidly drawn to the top of the cylinder, while the steam is
+displaced above, passing to the under-side of the piston.
+
+The valve _e_ is next closed, and _c_ and _f_ are again opened; the
+down-stroke is repeated. The water and air entering the condenser are
+removed at each stroke by the air-pump, _i_, which communicates with
+the condenser by the passage _s_. The pump _q_ supplies
+condensing-water, and the pump _A_ takes away a part of the water of
+condensation, which is thrown by the air-pump into the "hot-well,"
+_k_, and from it the feed-pump supplies the boiler. The valves are
+moved by valve-gear very similar to Beighton's and Smeaton's, by the
+pins, _m m_, in the "plug-frame" or "tappet-rod," _n n_.
+
+The engine is mounted upon a substantial foundation, _B B_. _F_ is an
+opening out of which, before starting the engine, the air is driven
+from the cylinder and condenser.
+
+The inventions covered by the patent of 1769 were described as
+follows:
+
+"My method of lessening the consumption of steam, and consequently
+fuel, in fire-engines, consists in the following principles:
+
+"1st. That the vessel in which the powers of steam are to be employed
+to work the engine--which is called 'the cylinder' in common
+fire-engines, and which I call 'the steam-vessel'--must, during the
+whole time that the engine is at work, be kept as hot as the steam
+which enters it; first, by inclosing it in a case of wood, or any
+other materials that transmit heat slowly; secondly, by surrounding
+it with steam or other heated bodies; and thirdly, by suffering
+neither water nor other substances colder than the steam to enter or
+touch it during that time.
+
+"2dly. In engines that are to be worked, wholly or partially, by
+condensation of steam, the steam is to be condensed in vessels
+distinct from the steam-vessel or cylinder, though occasionally
+communicating with them. These vessels I call condensers; and while
+the engines are working, these _condensers_ ought at least to be kept
+as cold as the air in the neighborhood of the engines, by application
+of water or other cold bodies.
+
+"3dly. Whatever air or other elastic vapor is not condensed by the
+cold of the condenser, and may impede the working of the engine, is to
+be drawn out of the steam-vessels or condensers by means of pumps,
+wrought by the engines themselves, or otherwise.
+
+"4thly. I intend in many cases to employ the expansive force of steam
+to press on the pistons, or whatever may be used instead of them, in
+the same manner as the pressure of the atmosphere is now employed in
+common fire-engines. In cases where cold water cannot be had in
+plenty, the engines may be wrought by this force of steam only, by
+discharging the steam into the open air after it has done its office.
+
+"5thly. Where motions round an axis are required, I make the
+steam-vessels in form of hollow rings or circular channels, with
+proper inlets and outlets for the steam, mounted on horizontal axles
+like the wheels of a water-mill. Within them are placed a number of
+valves that suffer any body to go round the channel in one direction
+only. In these steam-vessels are placed weights, so fitted to them as
+to fill up a part or portion of their channels, yet rendered capable
+of moving freely in them by the means hereinafter mentioned or
+specified. When the steam is admitted in these engines between these
+weights and the valves, it acts equally on both, so as to raise the
+weight on one side of the wheel, and, by the reaction of the valves
+successively, to give a circular motion to the wheel, the valves
+opening in the direction in which the weights are pressed, but not in
+the contrary. As the vessel moves round, it is supplied with steam
+from the boiler, and that which has performed its office may either be
+discharged by means of condensers, or into the open air.
+
+"6thly. I intend in some cases to apply a degree of cold not capable
+of reducing the steam to water, but of contracting it considerably, so
+that the engines shall be worked by the alternate expansion and
+contraction of the steam.
+
+"Lastly, instead of using water to render the piston or other parts of
+the engine air or steam-tight, I employ oils, wax, resinous bodies,
+fat of animals, quicksilver, and other metals, in their fluid state."
+
+In the construction and erection of his engines, Watt still had great
+difficulty in finding skillful workmen to make the parts with
+accuracy, to fit them with care, and to erect them properly when once
+finished. And the fact that both Newcomen and Watt met with such
+serious trouble, indicates that, even had the engine been designed
+earlier, it is quite unlikely that the world would have seen the
+steam-engine a success until this time, when mechanics were just
+acquiring the skill requisite for its construction. But, on the other
+hand, it is not at all improbable that, had the mechanics of an
+earlier period been as skillful and as well-educated in the manual
+niceties of their business, the steam-engine might have been much
+earlier brought into use.
+
+In the time of the Marquis of Worcester it would have probably been
+found impossible to obtain workmen to construct the steam-engine of
+Watt, had it been then invented. Indeed, Watt, upon one occasion,
+congratulated himself that one of his steam-cylinders only lacked
+_three-eighths_ of an inch of being truly cylindrical.
+
+The history of the steam-engine is from this time a history of the
+work of the firm of Boulton & Watt. Newcomen engines continued to be
+built for years after Watt went to Soho, and by many builders. A host
+of inventors still worked on the most attractive of all mechanical
+combinations, seeking to effect further improvements. Some inventions
+were made by contemporaries of Watt, as will be seen hereafter, which
+were important as being the germs of later growths; but these were
+nearly all too far in advance of the time, and nearly every successful
+and important invention which marked the history of steam-power for
+many years originated in the fertile brain of James Watt.
+
+The defects of the Newcomen engine were so serious, that it was no
+sooner known that Boulton of Soho had become interested in a new
+machine for raising water by steam-power, than inquiries came to him
+from all sides, from mine-owners who were on the point of being
+drowned out, and from proprietors whose profits were absorbed by the
+expense of pumping, and who were glad to pay the £5 per horse-power
+per year finally settled upon as royalty. The London municipal
+water-works authorities were also ready to negotiate for
+pumping-engines for raising water to supply the metropolis. The firm
+was therefore at once driven to make preparations for a large
+business.
+
+The first and most important matter, however, was to secure an
+extension of the patent, which was soon to expire. If not renewed, the
+15 years of study and toil, of poverty and anxiety, through which Watt
+had toiled, would prove profitless to the inventor, and the fruits of
+his genius would have become the unearned property of others. Watt
+saw, at one time, little hope of securing the necessary act of
+Parliament, and was greatly tempted to accept a position tendered him
+by the Russian Government, upon the solicitation of his old friend,
+Dr. Robison, then a Professor of Mathematics at the Naval School at
+Cronstadt. The salary was £1,000--a princely income for a man in
+Watt's circumstances, and a peculiar temptation to the needy
+mechanic.
+
+Watt, however, went to London, and, with the help of his own and of
+Boulton's influential friends, succeeded in getting his bill through.
+His patent was extended 24 years, and Boulton & Watt set about the
+work of introducing their engines with the industry and enterprise
+which characterized their every act.
+
+In the new firm, Boulton took charge of the general business, and Watt
+superintended the design, construction, and erection of their engines.
+Boulton's business capacity, with Watt's wonderful mechanical
+ability--Boulton's physical health, and his vigor and courage,
+offsetting Watt's feeble health and depression of spirits--and, more
+than all, Boulton's pecuniary resources, both in his own purse and in
+those of his friends, enabled the firm to conquer all difficulties,
+whether in finance, in litigation, or in engineering.
+
+It was only after the successful erection and operation of several
+engines that Boulton and Watt became legally partners. The understood
+terms were explicitly stated by Watt to include an assignment to
+Boulton of two-thirds the patent-right; Boulton paying all expenses,
+advancing stock in trade at an appraised valuation, on which it was to
+draw interest; Watt making all drawings and designs, and drawing
+one-third net profits.
+
+As soon as Watt was relieved of the uncertainties regarding his
+business connections, he married a second wife, who, as Arago says, by
+"her various talent, soundness of judgment, and strength of
+character," made a worthy companion to the large-hearted and
+large-brained engineer. Thenceforward his cares were only such as
+every business-man expects to be compelled to sustain, and the next
+ten years were the most prolific in inventions of any period in Watt's
+life.
+
+From 1775 to 1785 the partners acquired five patents, covering a large
+number of valuable improvements upon the steam-engine, and several
+independent inventions. The first of these patents covered the now
+familiar and universally-used copying-press for letters, and a
+machine for drying cloth by passing it between copper rollers filled
+with steam of sufficiently high temperature to rapidly evaporate the
+moisture. This patent was issued February 14, 1780.
+
+[Illustration: FIG. 27.--Watt's Engine, 1781.]
+
+In the following year, October 25, 1781, Watt patented five devices by
+which he obtained the rotary motion of the engine-shaft without the
+use of a crank. One of these was the arrangement shown in Fig. 27, and
+known as the "sun-and-planet" wheels. The crank-shaft carries a
+gear-wheel, which is engaged by another securely fixed upon the end of
+the connecting-rod. As the latter is compelled to revolve about the
+axis of the shaft by a tie which confines the connecting-rod end at a
+fixed distance from the shaft, the shaft-gear is compelled to revolve,
+and the shaft with it. Any desired velocity-ratio was secured by
+giving the two gears the necessary relative diameters. A fly-wheel was
+used to regulate the motion of the shaft.[39] Boulton & Watt used the
+sun-and-planet device on many engines, but finally adopted the crank,
+when the expiration of the patent held by Matthew Wasborough, and
+which had earlier date than Watt's patent of 1781, permitted them.
+Watt had proposed the use of a crank, it is said, as early as 1771,
+but Wasborough anticipated him in securing the patent. Watt had made a
+model of an engine with a crank and fly-wheel, and he has stated that
+one of his workmen, who had seen the model, described it to
+Wasborough, thus enabling the latter to deprive Watt of his own
+property. The proceeding excited great indignation on the part of
+Watt; but no legal action was taken by Boulton & Watt, as the
+overthrow of the patent was thought likely to do them injury by
+permitting its use by more active competitors and more ingenious men.
+
+  [39] For the privilege of using the fly-wheel to regulate the motion
+  of the engine, Boulton & Watt paid a royalty to Matthew Wasborough,
+  who had patented it, and who held also the patent for its
+  combination with a crank, as invented by Pickard and Steed.
+
+The next patent issued to Watt was an exceedingly important one, and
+of especial interest in a history of the development of the economical
+application of steam. This patent included:
+
+1. The expansion of steam, and six methods of applying the principle
+and of equalizing the expansive power.
+
+2. The double-acting steam-engine, in which the steam acts on each
+side of the piston alternately, the opposite side being in
+communication with the condenser.
+
+3. The double or coupled steam-engine--two engines capable of working
+together, or independently, as may be desired.
+
+4. The use of a rack on the piston-rod, working into a sector on the
+end of the beam, thus securing a perfect rectilinear motion of the
+rod.
+
+5. A rotary engine, or "steam-wheel."
+
+The efficiency to be secured by the expansion of steam had long been
+known to Watt, and he had conceived the idea of economizing some of
+that power, the waste of which was so plainly indicated by the violent
+rushing of the exhaust-steam into the condenser, as early as 1769.
+This was described in a letter to Dr. Small, of Birmingham, in May of
+that year. When experimenting at Kinneil, he had tried to determine
+the real value of the principle by trial on his small engine.
+
+Boulton had also recognized the importance of this improved method of
+working steam, and their earlier Soho engines were, as Watt said, made
+with cylinders "double the size wanted, and cut off the steam at
+half-stroke." But, though "this was a great saving of steam, so long
+as the valves remained as at first," the builders were so constantly
+annoyed by alterations of the valves by proprietors and their
+engineers, that they finally gave up that method of working, hoping
+ultimately to be able to resume it when workmen of greater
+intelligence and reliability could be found. The patent was issued
+July 17, 1782.
+
+Watt specified a cut-off at one-quarter stroke as usually best.
+
+Watt's explanation of the method of economizing by expansive working,
+as given to Dr. Small,[40] is worthy of reproduction. He says: "I
+mentioned to you a method of still doubling the effect of steam, and
+that tolerably easy, by using the power of steam rushing into a
+vacuum, at present lost. This would do a little more than double the
+effect, but it would too much enlarge the vessels to use it all. It is
+peculiarly applicable to wheel-engines, and may supply the want of a
+condenser where force of steam is only used; for, open one of the
+steam-valves and admit steam, until one-fourth of the distance between
+it and the next valve is filled with steam, shut the valve, and the
+steam will continue to expand and to pass round the wheel with a
+diminishing power, ending in one-fourth its first exertion. The sum of
+this series you will find greater than one-half, though only
+one-fourth steam was used. The power will indeed be unequal, but this
+can be remedied by a fly, or in several other ways."
+
+  [40] "Lives of Boulton and Watt," Smiles.
+
+It will be noticed that Watt suggests, above, the now well-known
+non-condensing engine. He had already, as has been seen, described it
+in his patent of 1769, as also the rotary engine.
+
+Watt illustrates and explains his idea very neatly, by a sketch
+similar to that here given (Fig. 28).
+
+Steam, entering the cylinder at _a_, is admitted until one-fourth the
+stroke has been made, when the steam-valve is closed, and the
+remainder of the stroke is performed without further addition of
+steam. The variation of steam-pressure is approximately inversely
+proportional to the variation of its volume. Thus, at half-stroke, the
+pressure becomes one-half that at which the steam was supplied to the
+cylinder. At the end of the stroke it has fallen to one-fourth the
+initial pressure. The pressure is always nearly equal to the product
+of the initial pressure and volume divided by the volume at the given
+instant. In symbols,
+
+         _PV_
+  _P´_ = ----.
+         _V´_
+
+It is true that the condensation of steam doing work changes this law
+in a marked manner; but the condensation and reëvaporation of steam,
+due to the transfer of heat to and from the metal of the cylinder,
+tends to compensate the first variation by a reverse change of
+pressure with change of volume.
+
+[Illustration: FIG. 28.--Expansion of Steam.]
+
+The sketch shows this progressive variation of pressure as expansion
+proceeds. It is seen that the work done per unit of volume of steam as
+taken from the boiler is much greater than when working without
+expansion. The product of the mean pressure by the volume of the
+cylinder is less, but the quotient obtained by dividing this quantity
+by the volume or weight of steam taken from the boiler, is much
+greater with than without expansion. For the case assumed and
+illustrated, the work done during expansion is one and two-fifths
+times that done previous to cutting off the steam, and the work done
+per pound of steam is 2.4 times that done without expansion.
+
+Were there no losses to be met with and to be exaggerated by the use
+of steam expansively, the gain would become very great with moderate
+expansion, amounting to twice the work done when "following" full
+stroke, when the steam is cut off at one-seventh. The estimated gain
+is, however, never realized. Losses by friction, by conduction and
+radiation of heat, and by condensation and reëvaporation in the
+cylinder--of which losses the latter are most serious--after passing a
+point which is variable, and which is determined by the special
+conditions in each case, augment with greater rapidity than the gain
+by expansion.
+
+In actual practice, it is rarely found, except where special
+precautions are taken to reduce these losses, that economy follows
+expansion to a greater number of volumes than about one-half the
+square root of the steam-pressure; i. e., about twice for 15 or 20
+pounds pressure, three times for about 30 pounds, and four and five
+times for 60 or 65 and for 100 to 125 pounds respectively. Watt very
+soon learned this general principle; but neither he, nor even many
+modern engineers, seem to have learned that too great expansion often
+gives greatly-reduced economy.
+
+The inequality of pressure due to expansion, to which he refers, was a
+source of much perplexity to Watt, as he was for a long time convinced
+that he must find some method of "equalizing" the consequent irregular
+effort of the steam upon the piston. The several methods of
+"equalizing the expansive power" which are referred to in the patent
+were attempts to secure this result. By one method, he shifted the
+centre as the beam vibrated, thus changing the lengths of the arms of
+that great lever, to compensate the change of moment consequent upon
+the change of pressure. He finally concluded that a fly-wheel, as
+first proposed by Fitzgerald, who advised its use on Papin's engine,
+would be the best device on engines driving a crank, and trusted to
+the inertia of a balance-weight in his pumping-engines, or to the
+weight of the pump-rods, and permitted the piston to take its own
+speed so far as it was not thus controlled.
+
+The double-acting engine was a modification of the single-acting
+engine, and was very soon determined upon after the successful working
+of the latter had become assured.
+
+Watt had covered in the top of his single-acting engine, to prevent
+cooling the interior of the cylinder by contact with the comparatively
+cold atmosphere. When this had been done, there was but a single step
+required to convert the machine into the double-acting engine. This
+alteration, by which the steam was permitted to act upon the upper and
+the lower sides of the piston alternately, had been proposed by Watt
+as early as 1767, and a drawing of the engine was laid before a
+committee of the House of Commons in 1774-'75. By this simple change
+Watt doubled the power of his engine. Although invented much earlier,
+the plan was not patented until he was, as he states, driven to take
+out the patent by the "plagiarists and pirates" who were always ready
+to profit by his ingenuity. This form of engine is now almost
+universally used. The single-acting pumping-engine remains in use in
+Cornwall, and in a few other localities, and now and then an engine is
+built for other purposes, in which steam acts only on one side of the
+piston; but these are rare exceptions to the general rule.
+
+The subject of his next invention was not less interesting. The
+double-cylinder or "compound" engine has now, after the lapse of
+nearly a century, become an important and usual type of engine. It is
+impossible to determine precisely to whom to award the credit of its
+first conception. Dr. Falk, in 1779, had proposed a double-acting
+engine, in which there were two single-acting cylinders, acting in
+opposite directions and alternately on opposite sides of a wheel, with
+which a rack on the piston-rod of each geared.
+
+Watt claimed that Hornblower, the patentee of the "compound engine,"
+was an infringer upon his patents; and, holding the patent on the
+separate condenser, he was able to prevent the engine of his
+competitor taking such form as to be successfully introduced. The
+Hornblower engine was soon given up.
+
+Watt stated that this form of engine had been invented by him as early
+as 1767, and that he had explained its peculiarities to Smeaton and
+others several years before Hornblower attempted to use it. He wrote
+to Boulton: "It is no less than our double-cylinder engine, worked
+upon our principle of expansion." He never made use of the plan,
+however; and the principal object sought, apparently, in patenting
+this, as well as many other devices, was to secure himself against
+competition.
+
+The rack and sector patented at this time was soon superseded by the
+parallel-motion; and the last claim, the "steam-wheel" or rotary
+engine, although one was built of considerable size, was not
+introduced.
+
+After the patent of 1782 had been secured, Watt turned his attention,
+when not too hard-pressed by business, to other schemes, and to
+experimenting with still other modifications and applications of his
+engine. He had, as early as 1777, proposed to make a steam-hammer for
+Wilkinson's forge; but he was too closely engaged with more important
+matters to take hold of the project with much earnestness until late
+in the year 1782, when, after some preliminary trials, he reported,
+December 13th: "We have tried our little tilting-forge hammer at Soho
+with success. The following are some of the particulars: Cylinder, 15
+inches in diameter; 4 feet stroke; strokes per minute, 20. The
+hammer-head, 120 pounds weight, rises 8 inches, and strikes 240 blows
+per minute. The machine goes quite regularly, and can be managed as
+easily as a water-mill. It requires a very small quantity of
+steam--not above half the contents of the cylinder per stroke. The
+power employed is not more than one-fourth of what would be required
+to raise the quantity of water which would enable a water-wheel to
+work the same hammer with the same velocity."
+
+He immediately set about making a much heavier hammer, and on April
+26, 1783, he wrote that he had done "a thing never done
+before"--making his hammer strike 300 blows a minute. This hammer
+weighed 7-1/2 hundredweight, and had a drop of 2 feet. The
+steam-cylinder had a diameter of 42 inches and 6 feet stroke of
+piston, and was calculated to have sufficient power to drive four
+hammers weighing 7 hundredweight each. The engine made 20 strokes per
+minute, the hammer giving 90 blows in the same time.
+
+This new application of steam-power proving successful, Watt next
+began to develop a series of minor inventions, which were finally
+secured by his patent of April 27, 1784, together with the steam
+tilt-hammer, and a steam-carriage, or "locomotive engine."
+
+The contrivance previously used for guiding the head of the
+piston-rod--the sectors and chains, or rack--had never given
+satisfaction. The rudeness of design of the contrivance was only
+equalled by its insecurity. Watt therefore contrived a number of
+methods of accomplishing the purpose, the most beautiful and
+widely-known of which is the "parallel-motion," although it has now
+been generally superseded by one of the other devices patented at the
+same time--the cross-head and guides. As originally proposed, a rod
+was attached to the head of the piston-rod, standing vertically when
+the latter was at quarter-stroke. The upper end of this rod was
+pivoted to the end of the beam, and the lower end to the extremity of
+a horizontal rod having a length equal to one-half the length of the
+beam. The other end of the horizontal rod was coupled to the frame of
+the engine. As the piston rose and fell, the upper and lower ends of
+the vertical rod were swayed in opposite directions, and to an equal
+extent, by the beam and the lower horizontal rod, the middle point at
+which the piston-rod was attached preserving its position in the
+vertical line. This form was objectionable, as the whole effort of the
+engine was transmitted through the parallel-motion rods. Another form
+is shown in the sketch given of the double-acting engine in Fig. 31,
+which was free from this defect. The head of the piston-rod, _g_, was
+guided by rods connecting it with the frame at _c_, and forming a
+"parallelogram," _g d e b_, with the beam. Many varieties of
+"parallel-motion" have been devised since Watt's invention was
+attached to his engines at Soho. They usually are more or less
+imperfect, guiding the piston-rod in a line only approximately
+straight.
+
+The cross-head and guides are now generally used, very much as
+described by Watt in this patent as his "second principle." This
+device will be seen in the engravings given hereafter of more modern
+engines. The head of the piston-rod is fitted into a transverse bar,
+or cross-head, which carries properly-shaped pieces at its
+extremities, to which are bolted "gibs," so made as to fit upon guides
+secured to the engine-frame. These guides are adjusted to precise
+parallelism with the centre line of the cylinder. The cross-head,
+sliding in or on these guides, moves in a perfectly straight line,
+and, compelling the piston-rod to move with it, the latter is even
+more perfectly guided than by a parallel-motion. This arrangement,
+where properly proportioned, is not necessarily subject to great
+friction, and is much more easily adjusted and kept in line than the
+parallel-motion when wear occurs or maladjustment takes place.
+
+By the same patent, Watt secured the now common "puppet-valve" with
+beveled seat, and the application of the steam-engine to driving
+rolling-mills and hammers for forges, and to "wheel-carriages for
+removing persons or goods, or other matters, from place to place." For
+the latter purpose he proposes to use boilers "of wood, or of thin
+metal, strongly secured by hoops or otherwise," and containing
+"internal fire-boxes." He proposed to use a condenser cooled by
+currents of air.
+
+It would require too much space to follow Watt in all his schemes for
+the improvement and for the application of the steam-engine. A few of
+the more important and more ingenious only can be described. Many of
+the contracts of Boulton & Watt gave them, as compensation for their
+engines, a fraction--usually one-third--of the value of the fuel saved
+by the use of the Watt engine in place of the engine of Newcomen, the
+amount due being paid annually or semiannually, with an option of
+redemption on the part of the purchaser at ten years' purchase. This
+form of agreement compelled a careful determination, often, of the
+work done and fuel consumed by both the engine taken out and that put
+in its place. It was impossible to rely upon any determination by
+personal observation of the number of strokes made by the engine. Watt
+therefore made a "counter," like that now familiar to every one as
+used on gas-meters. It consists of a train of wheels moving pointers
+on several dials, the first dial showing tens, the second hundreds,
+the third thousands, etc., strokes or revolutions. Motion was
+communicated to the train by means of a pendulum, the whole being
+mounted on the beam of the engine, where every vibration produced a
+swing of the pendulum. Eight dials were sometimes used, the counter
+being set and locked, and only opened once a year, when the time
+arrived for determining the work done during the preceding
+twelve-month.
+
+The application of his engine to purposes for which careful adjustment
+of speed was requisite, or where the load was subject to considerable
+variation, led to the use of a controlling-valve in the steam-pipe,
+called the "throttle-valve," which was adjustable by hand, and
+permitted the supply of steam to the engine to be adjusted at any
+instant and altered to any desired extent. It is now given many forms,
+but it still is most usually made just as originally designed by Watt.
+It consists of a circular disk, which just closes up the steam-pipe
+when set directly across it, or of an elliptical disk, which closes
+the pipe when standing at an angle of somewhat less than 90° with the
+line of the pipe. This disk is carried on a spindle extending through
+the pipe at one side, and carrying on its outer end an arm by means
+of which it may be turned into any position. When placed with its face
+in line with the pipe, it offers very little resistance to the flow of
+steam to the engine. When set in the other position, it shuts off
+steam entirely and stops the engine. It is placed in such position at
+any time, that the speed of the engine is just that required at the
+time. In the engraving of the double-acting engine with fly-wheel
+(Fig. 31), it is shown at _T_, as controlled by the governor.
+
+[Illustration: FIG. 29.--The Governor.]
+
+The governor, or "fly-ball governor," as it is often distinctively
+called, was another of Watt's minor but very essential inventions. Two
+heavy iron or brass balls, _B B´_, were suspended from pins, _C C´_,
+in a little cross-piece carried on the head of a vertical spindle, _A
+A´_, driven by the engine. The speed of the engine varying, that of
+the spindle changed correspondingly, and the faster the balls were
+swung the farther they separated. When the engine's speed decreased,
+the period of revolution of the balls was increased, and they fell
+back toward the spindle. Whenever the velocity of the engine was
+uniform, the balls preserved their distance from the spindle and
+remained at the same height, their altitude being determined by the
+relation existing between the force of gravity and centrifugal force
+in the temporary position of equilibrium. The distance from the point
+of suspension down to the level of the balls is always equal to 9.78
+inches divided by the square of the number of revolutions per
+second--i. e., _h_ = 9.78 (1/_N_^2) = 0.248 (1/_N_^2) meters.
+
+The arms carrying the balls, or the balls themselves, are pinned to
+rods, _M M´_, which are connected to a piece, _N N´_, sliding loosely
+on the spindle. A score, _T_, cut in this piece engages a lever, _V_,
+and, as the balls rise and fall, a rod, _W_, is moved, closing and
+opening the throttle-valve, and thus adjusting the supply of steam in
+such a way as to preserve a nearly fixed speed of engine. The
+connection with the throttle-valve and with the cut-off valve-gear is
+seen not only in the engraving of the double-acting Watt engine, but
+also in those of the Greene and the Corliss engines. This contrivance
+had previously been used in regulating water-wheels and windmills.
+Watt's invention consisted in its application to the regulation of the
+steam-engine.
+
+Still another useful invention of Watt's was his "mercury
+steam-gauge"--a barometer in which the height of the mercury was
+determined by the pressure of the steam instead of that of the
+atmosphere. This simple instrument consisted merely of a bent tube
+containing a portion of mercury. One leg, _B D_, of this U-tube was
+connected with the steam-pipe, or with the boiler by a small
+steam-pipe; the other end, _C_, was open to the atmosphere. The
+pressure of the steam on the mercury in _B D_ caused it to rise in the
+other "leg" to a height exactly proportioned to the pressure, and
+causing very nearly two inches difference of level to the pound, or
+one inch to the pound actual rise in the outer leg. The rude sketch
+from Farey, here given (Fig. 30), indicates sufficiently well the form
+of this gauge. It is still considered by engineers the most reliable
+of all forms of steam-gauge. Unfortunately, it is not conveniently
+applicable at high pressure. The scale, _A_, is marked with numbers
+indicating the pressure, which numbers are indicated by the head of a
+rod floating up with the mercury.
+
+A similar gauge was used to determine the degree of perfection of
+vacuum attained in the condenser, the mercury falling in the outer leg
+as the vacuum became more complete. A perfect vacuum would cause a
+depression of level in that leg to 30 inches below the level of the
+mercury in the leg connected with the condenser. In a more usual form,
+it consisted of a simple glass tube having its lower end immersed in a
+cistern of mercury, as in the ordinary barometer, the top of the tube
+being connected with a pipe leading to the condenser. With a perfect
+vacuum in the condenser, the mercury would rise in the tube very
+nearly 30 inches. Ordinarily, the vacuum is not nearly perfect, and, a
+back pressure remaining in the condenser of one or two pounds per
+square inch, the atmospheric pressure remaining unbalanced is only
+sufficient to raise the mercury 26 or 28 inches above the level of the
+liquid metal in the cistern.
+
+[Illustration: FIG. 30. Mercury Steam Gauge. Glass Water Gauge.]
+
+To determine the height of water in his boiler, Watt added to the
+gauge-cocks already long in use the "glass water-gauge," which is
+still seen in nearly every well-arranged boiler. This was a glass
+tube, _a a´_ (Fig. 30), mounted on a standard attached to the front of
+the boiler, and at such a height that its middle point was very little
+below the proposed water-level. It was connected by a small pipe, _r_,
+at the top to the steam-space, and another little pipe, _r´_, led into
+the boiler from its lower end below the water-line. As the water rose
+and fell within the boiler, its level changed correspondingly in the
+glass. This little instrument is especially liked, because the
+position of the water is at all times shown to the eye of the
+attendant. If carefully protected against sudden changes of
+temperature, it answers perfectly well with even very high pressures.
+
+The engines built by Boulton & Watt were finally fitted with the crank
+and fly-wheel for application to the driving of mills and machinery.
+The accompanying engraving (Fig. 31) shows the engine as thus made,
+combining all of the essential improvements designed by its inventor.
+
+In the engraving, _C_ is the steam-cylinder, _P_ the piston, connected
+to the beam by the link, _g_, and guided by the parallel-motion, _g d
+c_. At the opposite end of the beam a connecting-rod, _O_, connects
+with the crank and fly-wheel shaft. _R_ is the rod of the air-pump, by
+means of which the condenser is kept from being flooded by the water
+used for condensation, which water-supply is regulated by an
+"injection-handle," _E_. A pump-rod, _N_, leads down from the beam to
+the cold-water pump, by which water is raised from the well or other
+source to supply the needed injection-water. The air-pump rod also
+serves as a "plug-rod," to work the valves, the pins at _m_ and _R_
+striking the lever, _m_, at either end of the stroke. When the piston
+reaches the top of the cylinder, the lever, _m_, is raised, opening
+the steam-valve, _B_, at the top, and the exhaust-valve, _E_, at the
+bottom, and at the same time closing the exhaust at the top and the
+steam at the bottom. When the entrance of steam at the top and the
+removal of steam-pressure below the piston has driven the piston to
+the bottom, the pin, _R_, strikes the lever, _m_, opening the steam
+and closing the exhaust valve at the bottom, and similarly reversing
+the position of the valves at the top. The position of the valves is
+changed in this manner with every reversal of the motion of the piston
+as the crank "turns over the centre."
+
+[Illustration: FIG. 31.--Boulton & Watt's Double-Acting Engine, 1784.]
+
+The earliest engines of the double-acting kind, and of any
+considerable size, which were built to turn a shaft, were those which
+were set up in the Albion Mills, near Blackfriars' Bridge, London, in
+1786, and destroyed when the mills burned down in 1791. There were a
+pair of these engines (shown in Fig. 27), of 50 horse-power each, and
+geared to drive 20 pairs of stones, making fine flour and meal.
+Previous to the erection of this mill the power in all such
+establishments had been derived from windmills and water-wheels. This
+mill was erected by Boulton & Watt, and capitalists working with
+them, not only to secure the profit anticipated from locating a
+flour-mill in the city of London, but also with a view to exhibiting
+the capacity of the new double-acting "rotating" engine. The plan was
+proposed in 1783, and work was commenced in 1784; but the mill was not
+set in operation until the spring of 1786. The capacity of the mill
+was, in ordinary work, 16,000 bushels of wheat ground into fine flour
+per week. On one occasion, the mill turned out 3,000 bushels in 24
+hours. In the construction of the machinery of the mill, many
+improvements upon the then standard practice were introduced,
+including cast-iron gearing with carefully-formed teeth and iron
+framing. It was here that John Rennie commenced his work, after
+passing through his apprenticeship in Scotland, sending his chief
+assistant, Ewart, to superintend the erection of the milling
+machinery. The mill was a success as a piece of engineering, but a
+serious loss was incurred by the capitalists engaged in the
+enterprise, as it was set on fire a few years afterward and entirely
+destroyed. Boulton and Watt were the principal losers, the former
+losing £6,000, and the latter £3,000.
+
+The valve-gear of this engine, a view of which is given in Fig. 27,
+was quite similar to that used on the Watt pumping-engine. The
+accompanying illustration (Fig. 32) represents this valve-motion as
+attached to the Albion Mills engine.
+
+[Illustration: FIG. 32.--Valve-Gear of the Albion Mills Engine.]
+
+The steam-pipe, _a b d d e_, leads the steam from the boiler to the
+chambers, _b_ and _e_. The exhaust-pipe, _g g_, leads from _h_ and _i_
+to the condenser. In the sketch, the upper steam and the lower exhaust
+valves, _b_ and _f_, are opened, and the steam-valve, _e_, and
+exhaust-valve, _c_, are closed, the piston being near the upper end of
+the cylinder and descending. _l_ represents the plug-frame, which
+carries tappets, 2 and 3, which engage the lever, _s_, at either end
+of its throw, and turn the shaft, _u_, thus opening and closing _c_
+and _e_ simultaneously by means of the connecting-links, 13 and 14. A
+similar pair of tappets on the opposite side of the plug-rod move the
+valves, _b_ and _f_, by means of the rods, 10 and 11, the arm, _r_,
+when struck by those tappets, turning the shaft, _t_, and thus moving
+the arms to which those rods are attached. Counterbalance-weights,
+carried on the ends of the arms, 4 and 15, retain the valves on their
+seats when closed by the action of the tappets. When the piston nearly
+reaches the lower end of the cylinder, the tappet, 1, engages the arm,
+_r_, closing the steam-valve, _b_, and the next instant shutting the
+exhaust-valve, _f_. At the same time, the tappet, 3, by moving the
+arm, _s_, downward, opens the steam-valve, _e_, and the exhaust-valve,
+_c_. Steam now no longer issues from the steam-pipe into the space,
+_c_, and thence into the engine-cylinder (not shown in the sketch);
+but it now enters the engine through the valve, _e_, forcing the
+piston upwards. The exhaust is simultaneously made to occur at the
+upper end, the rejected steam passing from the engine into the space,
+_c_, and thence through _c_ and the pipe, _g_, into the condenser.
+
+This kind of valve-gear was subsequently greatly improved by Murdoch,
+Watt's ingenious and efficient foreman, but it is now entirely
+superseded on engines of this class by the eccentric, and the various
+forms of valve-gear driven by it.
+
+[Illustration: FIG. 33.--Watt's Half-Trunk Engine, 1784.]
+
+The "trunk-engine" was still another of the almost innumerable
+inventions of Watt. A half-trunk engine is described in his patent of
+1784, as shown in the accompanying sketch (Fig. 33), in which _A_ is
+the cylinder, _B_ the piston, and _C_ its rod, encased in the
+half-trunk, _D_. The plug-rod, _G_, moves the single pair of valves by
+striking the catches, _E_ and _F_, as was usual with Watt's earlier
+engines.
+
+Watt's steam-hammer was patented at the same time. It is seen in Fig.
+34, in which _A_ is the steam-cylinder and _B_ its rod, the engine
+being evidently of the form just described. It works a beam, _C C_,
+which in turn, by the rod, _M_, works the hammer-helve, _L J_, and the
+hammer, _L_. The beam, _F G_, is a spring, and the block, _N_, the
+anvil.
+
+[Illustration: FIG. 34.--The Watt Hammer, 1784.]
+
+Watt found it impossible to determine the duty of his engines at all
+times by measurement of the work itself, and endeavored to find a way
+of ascertaining the power produced, by ascertaining the pressure of
+steam within the cylinder. This pressure was so variable, and subject
+to such rapid as well as extreme fluctuations, that he found it
+impossible to make use of the steam-gauge constructed for use on the
+boiler. He was thus driven to invent a special instrument for this
+work, which he called the "steam-engine indicator." This consisted of
+a little steam-cylinder containing a nicely-fitting piston, which
+moved without noticeable friction through a range which was limited by
+the compression of a helical spring, by means of which the piston was
+secured to the top of its cylinder. The distance through which the
+piston rose was proportional to the pressure exerted upon it, and a
+pointer attached to its rod traversed a scale upon which the pressure
+per square inch could be read. The lower end of the instrument being
+connected with the steam-cylinder of the engine by a small pipe
+fitted with a cock, the opening of the latter permitted steam from the
+engine-cylinder to fill the indicator-cylinder, and the pressure of
+steam was always the same in both cylinders. The indicator-pointer
+therefore traversed the pressure-scale, always exhibiting the pressure
+existing at the instant in the cylinder of the engine. When the engine
+was at rest and steam off, the indicator-piston stood at the same
+level as when detached from the engine, and the pointer stood at 0 on
+the scale. When steam entered, the piston rose and fell with the
+fluctuations of pressure; and when the exhaust-valve opened,
+discharging the steam and producing a vacuum in the steam-cylinder,
+the pointer of the indicator dropped below 0, showing the degree of
+exhaustion. Mr. Southern, one of Watt's assistants, fitted the
+instrument with a sliding board, moved horizontally backward and
+forward by a cord or link-work connecting directly or indirectly with
+the engine-beam, and thus giving it a motion coincident with that of
+the piston. This board carried a piece of paper, upon which a pencil
+attached to the indicator piston-rod drew a curve. The vertical height
+of any point on this curve above the base-line measured the pressure
+in the cylinder at the moment when it was made, and the horizontal
+distance of the point from either end of the diagram determined the
+position, at the same moment, of the engine-piston. The curve thus
+inscribed, called the "indicator card," or indicator diagram,
+exhibiting every minute change in the pressure of steam in the engine,
+not only enabled the mean pressure and the power of the engine to be
+determined by its measurement, but, to the eye of the expert engineer,
+it was a perfectly legible statement of the position of the valves of
+the engine, and revealed almost every defect in the action of the
+engine which could not readily be detected by external examination. It
+has justly been called the "engineers' stethoscope," opening the
+otherwise inaccessible parts of the steam-engine to the inspection of
+the engineer even more satisfactorily than the stethoscope of the
+physician gives him a knowledge of the condition and working of organs
+contained within the human body. This indispensable and now familiar
+engineers' instrument has since been modified and greatly improved in
+detail.
+
+The Watt engine had, by the construction of the improvements described
+in the patents of 1782-'85, been given its distinctive form, and the
+great inventor subsequently did little more than improve it by
+altering the forms and proportions of its details. As thus practically
+completed, it embodied nearly all the essential features of the modern
+engine; and, as we have seen, the marked features of our latest
+practice--the use of the double cylinder for expansion, the cut-off
+valve-gear, and surface-condensation--had all been proposed, and to a
+limited extent introduced. The growth of the steam-engine has here
+ceased to be rapid, and the changes which followed the completion of
+the work of James Watt have been minor improvements, and rarely, if
+ever, real developments.
+
+Watt's mind lost none of its activity, however, for many years. He
+devised and patented a "smoke-consuming furnace," in which he led the
+gases produced on the introduction of fresh fuel over the already
+incandescent coal, and thus burned them completely. He used two fires,
+which were coaled alternately. Even when busiest, also, he found time
+to pursue more purely scientific studies. With Boulton, he induced a
+number of well-known scientific men living near Birmingham to join in
+the formation of a "Lunar Society," to meet monthly at the houses of
+its members, "at the full of the moon." The time was thus fixed in
+order that those members who came from a distance should be able to
+drive home, after the meetings, by moonlight. Many such societies were
+then in existence in England; but that at Birmingham was one of the
+largest and most distinguished of them all. Boulton, Watt, Drs. Small,
+Darwin, and Priestley, were the leaders, and among their occasional
+visitors were Herschel, Smeaton, and Banks. Watt called these meetings
+"Philosophers' meetings." It was during the period of most active
+discussion at the "philosophers' meetings" that Cavendish and
+Priestley were experimenting with mixtures of oxygen and hydrogen, to
+determine the nature of their combustion. Watt took much interest in
+the subject, and, when informed by Priestley that he and Cavendish had
+both noticed a deposit of moisture invariably succeeding the explosion
+of the mixed gases, when contained in a cold vessel, and that the
+weight of this water was approximately equal to the weight of the
+mixed gases, he at once came to the conclusion that the union of
+hydrogen with oxygen produced water, the latter being a chemical
+compound, of which the former were constituents. He communicated this
+reasoning, and the conclusions to which it had led him, to Boulton, in
+a letter written in December, 1782, and addressed a letter some time
+afterward to Priestley, which was to have been read before the Royal
+Society in April, 1783. The letter was not read, however, until a year
+later, and, three months after, a paper by Cavendish, making the same
+announcement, had been laid before the Society. Watt stated that both
+Cavendish and Lavoisier, to whom also the discovery is ascribed,
+received the idea from him.
+
+The action of chlorine in bleaching organic coloring-matters, by (as
+since shown) decomposing them and combining with their hydrogen, was
+made known to Watt by M. Berthollet, the distinguished French chemist,
+and the former immediately introduced its use into Great Britain, by
+inducing his father-in-law, Mr. Macgregor, to make a trial of it.
+
+The copartnership of Boulton & Watt terminated by limitation, and with
+the expiration of the patents under which they had been working, in
+the first year of the present century; and both partners, now old and
+feeble, withdrew from active business, leaving their sons to renew the
+agreement and to carry on the business under the same firm-style.
+
+Boulton, however, still interested himself in some branches of
+manufacture, especially in his mint, where he had coined many years
+and for several nations.
+
+Watt retired, a little later, to Heathfield, where he passed the
+remainder of his life in peaceful enjoyment of the society of his
+friends, in studies of all current matters of interest in science, as
+well as in engineering. One by one his old friends died--Black in
+1799, Priestley, an exile to America, in 1803, and Robison a little
+later. Boulton died, at the age of eighty-one, August 17, 1809, and
+even the loss of this nearest and dearest of his friends outside the
+family was a less severe blow than that of his son Gregory, who died
+in 1804.
+
+Yet the great engineer and inventor was not depressed by the
+loneliness which was gradually coming upon him. He wrote: "I know that
+all men must die, and I submit to the decrees of Nature, I hope, with
+due reverence to the Disposer of events;" and neglected no opportunity
+to secure amusement or instruction, and kept body and mind constantly
+occupied. He still attended the weekly meetings of the club, meeting
+Rennie and Telford, and other distinguished men of his own and the
+succeeding generation. He lost nothing of his fondness for invention,
+and spent many months in devising a machine for copying statuary,
+which he had not perfected to his own satisfaction at the time of his
+death, ten years later. This machine was a kind of pentagraph, which
+could be worked in any plane, and in which the marking-pencil gave
+place to a cutting-tool. The tracing-point followed the surface of the
+pattern, while the cutting-point, following its motion precisely,
+formed a fac-simile in the material operated upon.
+
+In the year 1800 he invented the water-main which was laid down by the
+Glasgow Water-Works Company across the Clyde. The joints were
+spherical and articulated, like those of the lobster's tail.
+
+His workshop, of which a sketch is hereafter given, as drawn by the
+artist Skelton, was in the garret of his house, and was well supplied
+with tools and all kinds of laboratory material. His lathe and his
+copying-machine were placed before the window, and his writing-desk in
+the corner. Here he spent the greater part of his leisure time, often
+even taking his meals in the little shop, rather than go to the table
+for them. Even when very old, he occasionally made a journey to London
+or Glasgow, calling on his old friends and studying the latest
+engineering devices and inspecting public works, and was everywhere
+welcomed by young and old as the greatest living engineer, or as the
+kind and wise friend of earlier days.
+
+He died August 19, 1819, in the eighty-third year of his age, and was
+buried in Handsworth Church. The sculptor Chantrey was employed to
+place a fitting monument above his grave, and the nation erected a
+statue of the great man in Westminster Abbey.
+
+This sketch of the greatest of all the inventors of the steam-engine
+has been given no greater length than its subject justifies. Whether
+we consider Watt as the inventor of the standard steam-engine of the
+nineteenth century, as the scientific investigator of the physical
+principles upon which the invention is based, or as the builder and
+introducer of the most powerful known instrument by which the "great
+sources of power in Nature are converted, adapted, and applied for the
+use and convenience of man," he is fully entitled to preëminence. His
+character as a man was no less admirable than as an engineer.
+
+Smiles, Watt's most conscientious and indefatigable biographer,
+writes:[41]
+
+  [41] "Life of Watt," p. 512.
+
+[Illustration: FIG. 35.--James Watt's Workshop. (From Smiles's "Lives
+of Boulton and Watt.")]
+
+"Some months since, we visited the little garret at Heathfield in
+which Watt pursued the investigations of his later years. The room had
+been carefully locked up since his death, and had only once been swept
+out. Everything lay very much as he left it. The piece of iron which
+he was last employed in turning, lay on the lathe. The ashes of the
+last fire were in the grate; the last bit of coal was in the scuttle.
+The Dutch oven was in its place over the stove, and the frying-pan in
+which he cooked his meals was hanging on its accustomed nail. Many
+objects lay about or in the drawers, indicating the pursuits which had
+been interrupted by death--busts, medallions, and figures, waiting to
+be copied by the copying-machine--many medallion-moulds, a store of
+plaster-of-Paris, and a box of plaster casts from London, the contents
+of which do not seem to have been disturbed. Here are Watt's ladles
+for melting lead, his foot-rule, his glue-pot, his hammer. Reflecting
+mirrors, an extemporized camera with the lenses mounted on pasteboard,
+and many camera-glasses laid about, indicate interrupted experiments
+in optics. There are quadrant-glasses, compasses, scales, weights, and
+sundry boxes of mathematical instruments, once doubtless highly
+prized. In one place a model of the governor, in another of the
+parallel-motion, and in a little box, fitted with wooden cylinders
+mounted with paper and covered with figures, is what we suppose to be
+a model of his calculating-machine. On the shelves are minerals and
+chemicals in pots and jars, on which the dust of nearly half a century
+has settled. The moist substances have long since dried up; the putty
+has been turned to stone, and the paste to dust. On one shelf we come
+upon a dish in which lies a withered bunch of grapes. On the floor, in
+a corner, near to where Watt sat and worked, is a hair-trunk--a
+touching memorial of a long-past love and a long-dead sorrow. It
+contains all poor Gregory's school-books, his first attempts at
+writing, his boy's drawings of battles, his first school-exercises
+down to his college-themes, his delectuses, his grammars, his
+dictionaries, and his class-books--brought into this retired room,
+where the father's eye could rest upon them. Near at hand is the
+sculpture-machine, on which he continued working to the last. Its
+wooden frame is worm-eaten, and dropping into dust, like the hands
+that made it. But though the great workman is gone to rest, with all
+his griefs and cares, and his handiwork is fast crumbling to decay,
+the spirit of his work, the thought which he put into his inventions,
+still survives, and will probably continue to influence the destinies
+of his race for all time to come."
+
+The visitor to Westminster Abbey will find neither monarch, nor
+warrior, nor statesman, nor poet, honored with a nobler epitaph than
+that which is inscribed on the pedestal of Chantrey's monument to
+Watt:
+
+                      NOT TO PERPETUATE A NAME,
+          WHICH MUST ENDURE WHILE THE PEACEFUL ARTS FLOURISH,
+                              BUT TO SHOW
+    THAT MANKIND HAVE LEARNT TO HONOR THOSE WHO BEST DESERVE THEIR
+                              GRATITUDE,
+                              THE KING,
+   HIS MINISTERS, AND MANY OF THE NOBLES AND COMMONERS OF THE REALM,
+                        RAISED THIS MONUMENT TO
+                              JAMES WATT,
+            WHO, DIRECTING THE FORCE OF AN ORIGINAL GENIUS,
+               EARLY EXERCISED IN PHILOSOPHIC RESEARCH,
+                         TO THE IMPROVEMENT OF
+                           THE STEAM-ENGINE,
+  ENLARGED THE RESOURCES OF HIS COUNTRY, INCREASED THE POWER OF MAN,
+                     AND ROSE TO AN EMINENT PLACE
+     AMONG THE MOST ILLUSTRIOUS FOLLOWERS OF SCIENCE AND THE REAL
+                       BENEFACTORS OF THE WORLD.
+
+                      BORN AT GREENOCK, MDCCXXXVI.
+
+            DIED AT HEATHFIELD, IN STAFFORDSHIRE, MDCCCXIX.
+
+[Illustration: Tomb of James Watt.]
+
+
+SECTION II.--THE CONTEMPORARIES OF JAMES WATT.
+
+In the chronology of the steam-engine, the contemporaries of Watt have
+been so completely overshadowed by the greater and more successful
+inventor, as to have been almost forgotten by the biographer and by
+the student of history. Yet, among the engineers and engine-builders,
+as well as among the inventors of his day, Watt found many
+enterprising rivals and keen competitors. Some of these men, had they
+not been so completely fettered by Watt's patents, would have probably
+done work which would have entitled them to far higher honor than has
+been accorded them.
+
+WILLIAM MURDOCH was one of the men to whom Watt, no less than the
+world, was greatly indebted. For many years he was the assistant,
+friend, and coadjutor of Watt; and it is to his ingenuity that we are
+to give credit for not only many independent inventions, but also for
+the suggestions and improvements which were often indispensable to the
+formation and perfection of some of Watt's own inventions.
+
+Murdoch was employed by Boulton & Watt in 1776, and was made
+superintendent of construction in the engine department, and given
+general charge of the erection of engines. He was sent into Cornwall,
+and spent in that district much of the time during which he served the
+firm, erecting pumping-engines, the construction of which for so many
+years constituted a large part of the business of the Soho
+establishment. He was looked upon by both Boulton and Watt as a
+sincere friend, as well as a loyal adherent, and from 1810 to 1830 was
+given a partner's share of the income of the firm, and a salary of
+£1,000. He retired from business at the last of the two dates named,
+and, dying in 1839, was buried near the two partners in Handsworth
+Church.
+
+Murdoch made a model, in 1784, of the locomotive patented by Watt in
+that year. He devised the arrangement of "sun-and-planet wheels,"
+adopted for a time in all of Watt's "rotative" engines, and invented
+the oscillating steam-engine (Fig. 36) in 1785, using the "D-slide
+valves," _G_, moved by the gear, _E_, which was driven by an eccentric
+on the shaft, without regard to the oscillation of the cylinder, _A_.
+He was the inventor of a rotary engine and of many minor machines for
+special purposes, and of many machine-tools used at Soho in building
+engines and machines. He seems, like Watt, to have had special
+fondness for the worm-gear, and introduced it wherever it could
+properly take the place of ordinary gearing. Some of the machines
+designed by Watt and Murdoch, who always worked well together, were
+found still in use and in good working condition by the author when
+visiting the works at Soho in 1873. The old mint in which, from 1797
+to 1805, Boulton had coined 4,000 tons of copper, had then been pulled
+down, and a new mint had been erected in 1860. Many old machines
+still remained about the establishment as souvenirs of the three great
+mechanics.
+
+[Illustration: FIG. 36.--Murdoch's Oscillating Engine, 1785.]
+
+Outside of Soho, Murdoch also found ample employment for his inventive
+talent. In 1792, while at Redruth, his residence before finally
+returning to Soho, he was led to speculate upon the possibility of
+utilizing the illuminating qualities of coal-gas, and, convinced of
+its practicability, he laid the subject before the Royal Society in
+1808, and was awarded the Rumford gold medal. He had, ten years
+earlier, lighted a part of the Soho works with coal-gas, and in 1803
+Watt authorized him to extend his pipes throughout all the buildings.
+Several manufacturers promptly introduced the new light, and its use
+extended very rapidly.
+
+Still another of Murdoch's favorite schemes was the transmission of
+power by the use of compressed air. He drove the pattern-shop engine
+at Soho by means of air from the blowing-engine in the foundery, and
+erected a pneumatic lift to elevate castings from the foundery-floor
+to the canal-bank. He made a steam-gun, introduced the heating of
+buildings by the circulation of hot water, and invented the method of
+transmitting packages through tubes by the impulse of compressed air,
+as now practised by the "pneumatic dispatch" companies. He died at the
+age of eighty-five years.
+
+Among the most active and formidable of Watt's business rivals was
+JONATHAN HORNBLOWER, the patentee of the "compound" or double-cylinder
+engine. A sketch of this engine, as patented by Hornblower in 1781, is
+here given (Fig. 37). It was first described by the inventor in the
+"Encyclopædia Britannica." It consists, as is seen by reference to the
+engraving, of two steam-cylinders, _A_ and _B_--_A_ being the low and
+_B_ the high pressure cylinder--the steam leaving the latter being
+exhausted into the former, and, after doing its work there, passing
+into the condenser, as already described. The piston-rods, _C_ and
+_D_, are both connected to the same part of the beam by chains, as in
+the other early engines. These rods pass through stuffing-boxes in the
+cylinder-heads, which are fitted up like those seen on the Watt
+engine. Steam is led to the engine through the pipe, _G Y_, and cocks,
+_a_, _b_, _c_, and _d_, are adjustable, as required, to lead steam
+into and from the cylinders, and are moved by the plug-rod, _W_, which
+actuates handles not shown. _K_ is the exhaust-pipe leading to the
+condenser. _V_ is the engine feed-pump rod, and _X_ the great rod
+carrying the pump-buckets at the bottom of the shaft.
+
+The cocks _c_ and _a_ being open and _b_ and _d_ shut, the steam
+passes from the boiler into the upper part of the steam-cylinder, _B_;
+and the communication between the lower part of _B_ and the top of _A_
+is also open. Before starting, steam being shut off from the engine,
+the great weight of the pump-rod, _X_, causes that end of the beam to
+preponderate, the pistons standing, as shown, at the top of their
+respective steam-cylinders.
+
+The engine being freed from all air by opening all the valves and
+permitting the steam to drive it through the engine and out of the
+condenser through the "snifting-valve," _O_, the valves _b_ and _d_
+are closed, and the cock in the exhaust-pipe opened.
+
+[Illustration: FIG. 37.--Hornblower's Compound Engine, 1781.]
+
+The steam beneath the piston of the large cylinder is immediately
+condensed, and the pressure on the upper side of that piston causes it
+to descend, carrying that end of the beam with it, and raising the
+opposite end with the pump-rods and their attachments. At the same
+time, the steam from the lower end of the small high-pressure cylinder
+being let into the upper end of the larger cylinder, the completion of
+the stroke finds a cylinder full of steam transferred from the one to
+the other with corresponding increase of volume and decrease of
+pressure. While expanding and diminishing in pressure as it passes
+from the smaller into the larger cylinder, this charge of steam
+gradually resists less and less the pressure of the steam from the
+boiler on the upper side of the piston of the small cylinder, _B_, and
+the net result is the movement of the engine by pressures exerted on
+the upper sides of both pistons and against pressures of less
+intensity on the under sides of both. The pressures in the lower part
+of the small cylinder, in the upper part of the large cylinder, and in
+the communicating passage, are evidently all equal at any given time.
+
+When the pistons have reached the bottoms of their respective
+cylinders, the valves at the top of the small cylinder, _B_, and at
+the bottom of the large cylinder, _A_, are closed, and the valves _c_
+and _d_ are opened. Steam from the boiler now enters beneath the
+piston of the small cylinder; the steam in the larger cylinder is
+exhausted into the condenser, and the steam already in the small
+cylinder passes over into the large cylinder, following up the piston
+as it rises.
+
+Thus, at each stroke a small cylinder full of steam is taken from the
+boiler, and the same weight, occupying the volume of the larger
+cylinder, is exhausted into the condenser from the latter cylinder.
+
+Referring to the method of operation of this engine, Prof. Robison
+demonstrated that the effect produced was the same as in Watt's
+single-cylinder engine--a fact which is comprehended in the law
+enunciated many years later by Rankine, that, "so far as the
+theoretical action of the steam on the piston is concerned, it is
+immaterial whether the expansion takes place in one cylinder, or in
+two or more cylinders." It was found, in practice, that the Hornblower
+engine was no more economical than the Watt engine; and that erected
+at the Tin Croft Mine, Cornwall, in 1792, did even less work with the
+same fuel than the Watt engines.
+
+Hornblower was prosecuted by Boulton & Watt for infringement. The suit
+was decided against him, and he was imprisoned in default of payment
+of the royalty, and fine demanded. He died a disappointed and
+impoverished man. The plan thus unsuccessfully introduced by
+Hornblower was subsequently modified and adopted by others among the
+contemporaries of Watt; and, with higher steam and the use of the Watt
+condenser, the "compound" gradually became a standard type of
+steam-engine.
+
+Arthur Woolf, in 1804, re-introduced the Hornblower or Falck engine,
+with its two steam-cylinders, using steam of higher tension. His first
+engine was built for a brewery in London, and a considerable number
+were subsequently made. Woolf expanded his steam from six to nine
+times, and the pumping-engines built from his plans were said to have
+raised about 40,000,000 pounds one foot high per bushel of coals, when
+the Watt engine was raising but little more than 30,000,000. In one
+case, a duty of 57,000,000 was claimed.
+
+The most successful of those competitors of Watt who endeavored to
+devise a peculiar form of pumping-engine, which should have the
+efficiency of that of Boulton & Watt, and the necessary advantage in
+first cost, were WILLIAM BULL and RICHARD TREVITHICK.[42] The
+accompanying illustration shows the design, which was then known as
+the "Bull Cornish Engine."
+
+  [42] For an exceedingly interesting and very faithful account of
+  their work, _see_ "Life of Richard Trevithick," by F. Trevithick,
+  London, 1872.
+
+[Illustration: FIG. 88.--Bull's Pumping-Engine, 1798.]
+
+The steam-cylinder, _a_, is carried on wooden beams, _b_, extending
+across the engine-house directly over the pump-well. The piston-rod,
+_c_, is secured to the pump-rods, _d d_, the cylinder being inverted,
+and the pumps, _e_, in the shaft, _f_, are thus operated without the
+intervention of the beam invariably seen in Watt's engines. A
+connecting-rod, _g_, attached to the pump-rod and to the end of a
+balance-beam, _h_, operates the latter, and is counterbalanced by a
+weight, _i_. The rod, _j_, serves both as a plug-rod and as an
+air-pump connecting-rod. A snifting-valve, _k_, opens when the engine
+is blown through, and relieves the condenser and air-pump, _l_, of all
+air. The rod, _m_, operates a solid air-pump piston, the valves of the
+pump being placed on either side at the base, instead of in the
+pump-bucket, as in Watt's engines. The condensing-water cistern was a
+wooden tank, _n_. A jet "pipe-condenser," _o_, was used instead of a
+jet condenser of the form adopted by other makers, and was supplied
+with water through the cock, _p_. The plug-rod, _q_, as it rises and
+falls with the pump-rods and balance-beam, operates the
+"gear-handles," _r r_, and opens and closes the valves, _s s_, at the
+required points in the stroke. The attendant works these valves by
+hand, in starting, from the floor, _t_. The operation of the engine is
+similar to that of a Watt engine. It is still in use, with a few
+modifications and improvements, and is a very economical and durable
+machine. It has not been as generally adopted, however, as it would
+probably have been had not the legal proscription of Watt's patents so
+seriously interfered with its introduction. Its simplicity and
+lightness are decided advantages, and its designers are entitled to
+great credit for their boldness and ingenuity, as displayed in their
+application of the minor devices which distinguish the engine. The
+design is probably to be credited to Bull originally; but Trevithick
+built some of these engines, and is supposed to have greatly improved
+them while working with Edward Bull, the son of the inventor, William
+Bull. One of these engines was erected by them at the Herland Mine,
+Cornwall, in 1798, which had a steam-cylinder 60 inches in diameter,
+and was built on the plan just described.
+
+Another of the contemporaries of James Watt was a clergyman, EDWARD
+CARTWRIGHT, the distinguished inventor of the power-loom, and of the
+first machine ever used in combing wool, who revived Watt's plan of
+surface-condensation in a somewhat modified form. Watt had made a
+"pipe-condenser," similar in plan to those now often used, but
+had simply immersed it in a tank of water, instead of in a
+constantly-flowing stream. Cartwright proposed to use two concentric
+cylinders or spheres, between which the steam entered when exhausted
+from the cylinder of the engine, and was condensed by contact with
+the metal surfaces. Cold water within the smaller and surrounding the
+exterior vessel kept the metal cold, and absorbed the heat discharged
+by the condensing vapor.
+
+Cartwright's engine is best described in the _Philosophical Magazine_
+of June, 1798, from which the accompanying sketch is copied.
+
+[Illustration: FIG. 39.--Cartwright's Engine, 1798.]
+
+The object of the inventor is stated to have been to remedy the
+defects of the Watt engine--imperfect vacuum, friction, and
+complication.
+
+In the figure, the steam-cylinder takes steam through the pipe, _B_.
+The piston, _R_, has a rod extending downward to the smaller
+pump-piston, _G_, and upward to the cross-head, which, in turn, drives
+the cranks above, by means of connecting-rods. The shafts thus turned
+are connected by a pair of gears, _M L_, of which one drives a pinion
+on the shaft of the fly-wheel. _D_ is the exhaust-pipe leading to the
+condenser, _F_; and the pump, _G_, removes the air and water of
+condensation, forcing it into the hot-well, _H_, whence it is returned
+to the boiler through the pipe, _I_. A float in _H_ adjusts an
+air-valve, so as to keep a supply of air in the chamber, to serve as a
+cushion and to make an air-chamber of the reservoir, and permits the
+excess to escape. The large tank contains the water supplied for
+condensing the steam.
+
+The piston, _R_, is made of metal, and is packed with two sets of cut
+metal rings, forced out against the sides of the cylinder by steel
+springs, the rings being cut at three points in the circumference, and
+kept in place by the springs. The arrangement of the two cranks, with
+their shafts and gears, is intended to supersede Watt's plan for
+securing a perfectly rectilinear movement of the head of the
+piston-rod, without friction.
+
+In the accounts given of this engine, great stress is laid upon the
+supposed important advantage here offered, by the introduction of the
+surface-condenser, of permitting the employment of a working-fluid
+other than steam--as, for example, alcohol, which is too valuable to
+be lost. It was proposed to use the engine in connection with a still,
+and thus to effect great economy by making the fuel do double duty.
+The only part of the plan which proved both novel and valuable was the
+metallic packing and piston, which has not yet been superseded. The
+engine itself never came into use.
+
+At this point, the history of the steam-engine becomes the story of
+its applications in several different directions, the most important
+of which are the raising of water--which had hitherto been its only
+application--the locomotive-engine, the driving of mill-machinery, and
+steam-navigation.
+
+Here we take leave of James Watt and of his contemporaries, of the
+former of whom a French author[43] says: "The part which he played in
+the mechanical applications of the power of steam can only be compared
+to that of Newton in astronomy and of Shakespeare in poetry." Since
+the time of Watt, improvements have been made principally in matters
+of mere detail, and in the extension of the range of application of
+the steam-engine.
+
+  [43] Bataille. "Traité des Machines à Vapeur," Paris, 1847.
+
+[Illustration]
+
+
+
+
+CHAPTER IV.
+
+_THE MODERN STEAM-ENGINE._
+
+  "Those projects which abridge distance have done most for the
+  civilization and happiness of our species."--MACAULAY.
+
+THE SECOND PERIOD OF APPLICATION--1800-'40.
+
+STEAM-LOCOMOTION ON RAILROADS.
+
+
+[Illustration: FIG. 40.--The First Railroad-Car, 1825.]
+
+Introductory.--The commencement of the nineteenth century found the
+modern steam-engine fully developed in all its principal features, and
+fairly at work in many departments of industry. The genius of
+Worcester, and Morland, and Savery, and Desaguliers, had, in the first
+period of the application of the power of steam to useful work,
+effected a beginning which, looked upon from a point of view which
+exhibits its importance as the first step toward the wonderful results
+to-day familiar to every one, appears in its true light, and entitles
+those great men to even greater honor than has been accorded them. The
+results actually accomplished, however, were absolutely insignificant
+in comparison with those which marked the period of development just
+described. Yet even the work of Watt and of his contemporaries was but
+a mere prelude to the marvellous advances made in the succeeding
+period, to which we are now come, and, in extent and importance, was
+insignificant in comparison with that accomplished by their successors
+in the development of all mechanical industries by the application of
+the steam-engine to the movement of every kind of machine.
+
+The first of the two periods of application saw the steam-engine
+adapted simply to the elevation of water and the drainage of mines;
+during the second period it was adapted to every variety of useful
+work, and introduced wherever the muscular strength of men and
+animals, or the power of wind and of falling water, which had
+previously been the only motors, had found application. A history of
+the development of industries by the introduction of steam-power
+during this period, would be no less extended and hardly less
+interesting than that of the steam-engine itself.
+
+The way had been fairly opened by Boulton and Watt; and the year 1800
+saw a crowd of engineers and manufacturers entering upon it, eager to
+reap the harvest of distinction and of pecuniary returns which seemed
+so promising to all. The last year of the eighteenth century was also
+the last of the twenty-five years of partnership of Boulton & Watt,
+and, with it, the patents under which that firm had held the great
+monopoly of steam-engine building expired. The right to manufacture
+the modern steam-engine was common to all. Watt had, at the
+commencement of the new century, retired from active business-life.
+Boulton remained in business; but he was not the inventor of the new
+engine, and could not retain, by the exercise of all his remaining
+power, the privileges previously held by legal authorization.
+
+The young Boulton and the young Watt were not the Boulton & Watt of
+earlier years; and, had they possessed all of the business talent and
+all of the inventive genius of their fathers, they could not have
+retained control of a business which was now growing far more rapidly
+than the facilities for manufacturing could be extended in any single
+establishment. All over the country, and even on the Continent of
+Europe, and in America, thousands of mechanics, and many men of
+mechanical tastes in other professions, were familiar with the
+principles of the new machine, and were speculating upon its value for
+all the purposes to which it has since been applied; and a multitude
+of enthusiastic mechanics, and a larger multitude of visionary and
+ignorant schemers, were experimenting with every imaginable device, in
+the vain hope of attaining perpetual motion, and other hardly less
+absurd results, by its modification and improvement. Steam-engine
+building establishments sprang up wherever a mechanic had succeeded in
+erecting a workshop and in acquiring a local reputation as a worker in
+metal, and many of Watt's workmen went out from Soho to take charge of
+the work done in these shops. Nearly all of the great establishments
+which are to-day most noted for their extent and for the importance
+and magnitude of the work done in them, not only in Great Britain, but
+in Europe and the United States, came into existence during this
+second period of the application of the steam-engine as a prime mover.
+
+The new establishments usually grew out of older shops of a less
+pretentious character, and were managed by men who had been trained by
+Watt, or who had had a still more awakening experience with those who
+vainly strove to make up, by their ingenuity and by great excellence
+of workmanship, the advantages possessed at Soho in a legal monopoly
+and greater experience in the business.
+
+It was exceedingly difficult to find expert and conscientious workmen,
+and machine-tools had not become as thoroughly perfected as had the
+steam-engine itself. These difficulties were gradually overcome,
+however, and thenceforward the growth of the business was increasingly
+rapid.
+
+Every important form of engine had now been invented. Watt had
+perfected, with the aid of Murdoch, both the pumping-engine and the
+rotative steam-engine for application to mills. He had invented the
+trunk engine, and Murdoch had devised the oscillating engine and the
+ordinary slide-valve, and had made a model locomotive-engine, while
+Hornblower had introduced the compound engine. The application of
+steam to navigation had been often proposed, and had sometimes been
+attempted, with sufficient success to indicate to the intelligent
+observer an ultimate triumph. It only remained to extend the use of
+steam as a motor into all known departments of industry, and to effect
+such improvements in details as experience should prove desirable.
+
+The engines of Hero, of Porta, and of Branca were, it will be
+remembered, non-condensing; but the first plan of a non-condensing
+engine that could be made of any really practical use is given in the
+"Theatrum Machinarum" of Leupold, published in 1720. This sketch is
+copied in Fig. 41. It is stated by Leupold that this plan was
+suggested by Papin. It consists of two single-acting cylinders, _r s_,
+receiving steam alternately from the same steam-pipe through a
+"four-way cock," _x_, and exhausting into the atmosphere. Steam is
+furnished by the boiler, _a_, and the pistons, _c d_, are alternately
+raised and depressed, depressing and raising the pump-rods, _k l_, to
+which they are attached by the beams, _h g_, vibrating on the centres,
+_i i_. The water from the pumps, _o p_, is forced up the stand-pipe,
+_q_, and discharged at its top. The alternate action of the
+steam-pistons is secured by turning the "four-way cock," _x_, first
+into the position shown, and then, at the completion of the stroke,
+into the reverse position, by which change the steam from the boiler
+is then led into the cylinder, _s_, and the steam in _r_ is discharged
+into the atmosphere.[44]
+
+  [44] _Vide_ "Theatrum Machinarum," vol. iii., Tab. 30.
+
+[Illustration: FIG. 41.--Leupold's Engine, 1720.]
+
+Leupold states that he is indebted to Papin for the suggestion of the
+peculiar valve here used. He also proposed to use a Savery engine
+without condensation in raising water. We have no evidence that this
+engine was ever built.
+
+The first rude scheme for applying steam to locomotion on land was
+probably that of Isaac Newton, who, in 1680, proposed the machine
+shown in the accompanying figure (42), which will be recognized as
+representing the scientific toy which is found in nearly every
+collection of illustrative philosophical apparatus. As described in
+the "Explanation of the Newtonian Philosophy," it consists of a
+spherical boiler, _B_, mounted on a carriage. Steam issuing from the
+pipe, _C_, seen pointing directly backward, by its reaction upon the
+carriage, drives the latter ahead. The driver, sitting at _A_,
+controls the steam by the handle, _E_, and cock, _F_. The fire is seen
+at _D_.
+
+[Illustration: FIG. 42.--Newton's Steam-Carriage, 1680.]
+
+When, at the end of the eighteenth century, the steam-engine had been
+so far perfected that the possibility of its successful application to
+locomotion had become fully and very generally recognized, the problem
+of adapting it to locomotion on land was attacked by many inventors.
+
+Dr. Robison had, as far back as in 1759, proposed it to James Watt
+during one of their conferences, at a time when the latter was even
+more ignorant than the former of the principles which were involved in
+the construction of the steam-engine, and this suggestion may have had
+some influence in determining Watt to pursue his research; thus
+setting in operation that train of thoughtful investigation and
+experiment which finally earned for him his splendid fame.
+
+In 1765, that singular genius, Dr. Erasmus Darwin, whose celebrity was
+acquired by speculations in poetry and philosophy as well as in
+medicine, urged Matthew Boulton--subsequently Watt's partner, and just
+then corresponding with our own Franklin in relation to the use of
+steam-power--to construct a steam-carriage, or "fiery chariot," as he
+poetically styled it, and of which he sketched a set of plans. A young
+man named Edgeworth became interested in the scheme, and, in 1768,
+published a paper which had secured for him a gold medal from the
+Society of Arts. In this paper he proposed railroads on which the
+carriages were to be drawn by horses, _or by ropes from steam-winding
+engines_.
+
+[Illustration: FIG. 43.--Read's Steam-Carriage, 1790.]
+
+Nathan Read, of whom an account will be given hereafter, when
+describing his attempt to introduce steam-navigation, planned, and in
+1790 obtained a patent for, a steam-carriage, of which the sketch seen
+in Fig. 43 is copied from the rough drawing accompanying his
+application. In the figure, _A A A A_ are the wheels; _B B_, pinions
+on the hubs of the rear wheels, which are driven by a ratchet
+arrangement on the racks, _G G_, connected with the piston-rods; _C o_
+is the boiler; _D D_, the steam-pipes carrying steam to the
+steam-cylinder, _E E_; _F F_ are the engine-frames; _H_ is the
+"tongue" or "pole" of the carriage, and is turned by a horizontal
+steering-wheel, with which it is connected by the ropes or chains, _I
+K_, _I K_; _W W_ are the cocks, which serve to shut off steam from the
+engine when necessary, and to determine the amount of steam to be
+admitted. The pipes _a a_ are exhaust-pipes, which the inventor
+proposed to turn so that they should point backward, in order to
+secure the advantage of the effort of reaction of the expelled steam.
+(!)
+
+Read made a model steam-carriage, which he exhibited when endeavoring
+to secure assistance in furtherance of his schemes, but seems to have
+given more attention to steam-navigation, and nothing was ever
+accomplished by him in this direction.
+
+These were merely promising schemes, however. The first actual
+experiment was made, as is supposed, by a French army-officer,
+NICHOLAS JOSEPH CUGNOT, who in 1769 built a steam-carriage, which was
+set at work in presence of the French Minister of War, the Duke de
+Choiseul. The funds required by him were furnished by the Compte de
+Saxe. Encouraged by the partial success of the first locomotive, he,
+in 1770, constructed a second (Fig. 44), which is still preserved in
+the Conservatoire des Arts et Métiers, Paris.
+
+[Illustration: FIG. 44.--Cugnot's Steam-Carriage, 1770.]
+
+This machine, when recently examined by the author, was still in an
+excellent state of preservation. The carriage and its machinery are
+substantially built and well-finished, and exceedingly creditable
+pieces of work in every respect. It surprises the engineer to find
+such evidence of the high character of the work of the mechanic
+Brezin a century ago. The steam-cylinders were 13 inches in diameter,
+and the engine was evidently of considerable power. This locomotive
+was intended for the transportation of artillery. It consists of two
+beams of heavy timber extending from end to end, supported by two
+strong wheels behind, and one still heavier but smaller wheel in
+front. The latter carries on its rim blocks which cut into the soil as
+the wheel turns, and thus give greater holding power. The single wheel
+is turned by two single-acting engines, one on each side, supplied
+with steam by a boiler (seen in the sketch) suspended in front of the
+machine. The connection between the engines and the wheels was
+effected by means of pawls, as first proposed by Papin, which could be
+reversed when it was desired to drive the machine backward. A seat is
+mounted on the carriage-body for the driver, who steers the machine by
+a train of gearing, which turns the whole frame, carrying the
+machinery 15 or 20 degrees either way. This locomotive was found to
+have been built on a tolerably satisfactory general plan; but the
+boiler was too small, and the steering apparatus was incapable of
+handling the carriage with promptness.
+
+The death of one of Cugnot's patrons, and the exile of the other, put
+an end to Cugnot's experiments.
+
+Cugnot was a mechanic by choice, and exhibited great talent. He was a
+native of Vaud, in Lorraine, where he was born in 1725. He served both
+in the French and the German armies. While under the Maréchal de Saxe,
+he constructed his first steam locomotive-engine, which only
+disappointed him, as he stated, in consequence of the inefficiency of
+the feed-pumps. The second was that built under the authority of the
+Minister Choiseul, and cost 20,000 livres. Cugnot received from the
+French Government a pension of 600 livres. He died in 1804, at the age
+of seventy-nine years.
+
+Watt, at a very early period, proposed to apply his own engine to
+locomotion, and contemplated using either a non-condensing engine or
+an air-surface condenser. He actually included the locomotive-engine
+in his patent of 1784; and his assistant, Murdoch, in the same year,
+made a working-model locomotive (Fig. 45), which was capable of
+running at a rapid rate. This model, now deposited in the Patent
+Museum at South Kensington, London, had a flue-boiler, and its
+steam-cylinder was three-fourths of an inch in diameter, and the
+stroke of piston 2 inches. The driving-wheels were 9-1/2 inches
+diameter.
+
+[Illustration: FIG. 45.--Murdoch's Model, 1784.]
+
+Nothing was, however, done on a larger scale by either Watt or
+Murdoch, who both found more than enough to claim their attention in
+the construction and introduction of other engines. Murdoch's model is
+said to have run from 6 to 8 miles an hour, its little driving-wheels
+making from 200 to 275 revolutions per minute. As is seen in the
+sketch, this model was fitted with the same form of engine, known as
+the "grasshopper-engine," which was used in the United States by
+Oliver Evans.
+
+"To Oliver Evans," says Dr. Ernest Alban, the distinguished German
+engineer, "was it reserved to show the true value of a long-known
+principle, and to establish thereon a new and more simple method of
+applying the power of steam--a method that will remain an eternal
+memorial to its introducer." Dr. Alban here refers to the earliest
+permanently successful introduction of the non-condensing
+high-pressure steam-engine.
+
+OLIVER EVANS, one of the most ingenious mechanics that America has
+ever produced, was born at Newport, Del., in 1755 or 1756, the son of
+people in very humble circumstances.
+
+[Illustration: Oliver Evans.]
+
+He was, in his youth, apprenticed to a wheelwright, and soon exhibited
+great mechanical talent and a strong desire to acquire knowledge. His
+attention was, at an early period, drawn to the possible application
+of the power of steam to useful purposes by the boyish pranks of one
+of his comrades, who, placing a small quantity of water in a
+gun-barrel, and ramming down a tight wad, put the barrel in the fire
+of a blacksmith's forge. The loud report which accompanied the
+expulsion of the wad was an evidence to young Evans of great and (as
+he supposed) previously undiscovered power.
+
+Subsequently meeting with a description of a Newcomen engine, he at
+once noticed that the elastic force of confined steam was not there
+utilized. He then designed the non-condensing engine, in which the
+power was derived exclusively from the tension of high-pressure steam,
+and proposed its application to the propulsion of carriages.
+
+About the year 1780, Evans joined his brothers, who were millers by
+occupation, and at once employed his inventive talent in improving the
+details of mill-work, and with such success as to reduce the cost of
+attendance one-half, and also to increase the fineness of the flour
+made. He proved himself a very expert millwright.
+
+In 1786 he applied to the Pennsylvania Legislature for a patent for
+the application of the steam-engine to driving mills, and to the
+steam-carriage, but was refused it. In 1800 or 1801, Evans, after
+consultation with Professor Robert Patterson, of the University of
+Pennsylvania, and getting his approval of the plans, commenced the
+construction of a steam-carriage to be driven by a non-condensing
+engine. He soon concluded, however, that it would be a better scheme,
+pecuniarily, to adapt his engine, which was novel in form and of small
+first cost, to driving mills; and he accordingly changed his plans,
+and built an engine of 6 inches diameter of cylinder and 18 inches
+stroke of piston, which he applied with perfect success to driving a
+plaster-mill.
+
+This engine, which he called the "Columbian Engine," was of a peculiar
+form, as seen in Fig. 46. The beam is supported at one end by a
+rocking column; at the other, it is attached directly to the
+piston-rod, while the crank lies beneath the beam, the connecting-rod,
+1, being attached to the latter at the extreme end. The head of the
+piston-rod is compelled to rise and fall in a vertical line by the
+"Evans's parallelogram"--a kind of parallel-motion very similar to
+one of those designed by Watt. In the sketch (Fig. 46), 2 is the
+crank, 3 the valve-motion, 4 the steam-pipe from the boiler, _E_, 5 6
+7 the feed-pipe leading from the pump, _F_. _A_ is the boiler. The
+flame from the fire on the grate, _H_, passes under the boiler between
+brick walls, and back through a central flue to the chimney, _I_.
+
+[Illustration: FIG. 46.--Evans's Non-condensing Engine, 1800.]
+
+Subsequently, Evans continued to extend the applications of his engine
+and to perfect its details; and, others following in his track, the
+non-condensing engine is to-day fulfilling the predictions which he
+made 70 years ago, when he said:
+
+"I have no doubt that my engines will propel boats against the current
+of the Mississippi, and wagons on turnpike roads, with great
+profit...."
+
+"The time will come when people will travel in stages moved by
+steam-engines from one city to another, almost as fast as birds can
+fly, 15 or 20 miles an hour.... A carriage will start from Washington
+in the morning, the passengers will breakfast at Baltimore, dine at
+Philadelphia, and sup in New York the same day....
+
+"Engines will drive boats 10 or 12 miles an hour, and there will be
+hundreds of steamers running on the Mississippi, as predicted years
+ago."[45]
+
+  [45] Evans's prediction is less remarkable than that of Darwin,
+  elsewhere quoted.
+
+In 1804, Evans applied one of his engines in the transportation of a
+large flat-bottomed craft, built on an order of the Board of Health of
+Philadelphia, for use in clearing some of the docks along the
+water-front of the city. Mounting it on wheels, he placed in it one of
+his 5-horse power engines, and named the odd machine (Fig. 47)
+"Oruktor Amphibolis." This steam dredging-machine, weighing about
+40,000 pounds, was then propelled very slowly from the works, up
+Market Street, around to the Water-Works, and then launched into the
+Schuylkill. The engine was then applied to the paddle-wheel at the
+stern, and drove the craft down the river to its confluence with the
+Delaware.
+
+[Illustration: FIG. 47.--Evans's "Oruktor Amphibolis," 1804.]
+
+In September of the same year, Evans laid before the Lancaster
+Turnpike Company a statement of the estimated expenses and profits of
+steam-transportation on the common road, assuming the size of the
+carriage used to be sufficient for transporting 100 barrels of flour
+50 miles in 24 hours, and placed in competition with 10 wagons drawn
+by 5 horses each.
+
+In the sketch above given of the "Oruktor Amphibolis," the engine is
+seen to resemble that previously described. The wheel, _A_, is driven
+by a rod depending from the end of a beam, _B´ B_, the other end of
+which is supported at _E_ by the frame, _E F G_. The body of the
+machine is carried on wheels, _K K_, driven by belts, _M M_, from the
+pulley on the shaft carrying _A_. The paddle-wheel is seen at _W_.
+Evans had some time previously sent Joseph Sampson to England with
+copies of his plans, and by him they were shown to Trevithick, Vivian,
+and other British engineers.
+
+Among other devices, the now familiar Cornish boiler, having a single
+internal flue, and the Lancashire boiler, having a pair of internal
+flues, were planned and used by Evans.
+
+At about the time that he was engaged on his steam dredging-machine,
+Evans communicated with Messrs. McKeever & Valcourt, who contracted
+with him to build an engine for a steam-vessel to ply between New
+Orleans and Natchez on the Mississippi, the hull of the vessel to be
+built on the river, and the machinery to be sent to the first-named
+city to be set up in the boat. Financial difficulties and low water
+combined to prevent the completion of the steamer, and the engine was
+set at work driving a saw-mill, where, until the mill was destroyed by
+fire, it sawed lumber at the rate of 250 feet of boards per hour.
+
+Evans never succeeded in accomplishing in America as great a success
+as had rewarded Watt in Great Britain; but he continued to build
+steam-engines to the end of his life, April 19, 1819, and was
+succeeded by his sons-in-law, James Rush and David Muhlenberg.
+
+He exhibited equal intelligence and ingenuity in perfecting the
+processes of milling, and in effecting improvements in his own
+business, that of the millwright. When but twenty-four years old, he
+invented a machine for making the wire teeth used in cotton and
+woolen cards, turning them out at the rate of 3,000 per minute. A
+little later he invented a card-setting machine, which cut the wire
+from the reel, bent the teeth, and inserted them. In milling, he
+invented a whole series of machines and attachments, including the
+elevator, the "conveyor," the "hopper-box," the "drill," and the
+"descender," and enabled the miller to make finer flour, gaining over
+20 pounds to the barrel, and to do this at half the former cost of
+attendance. The introduction of his improvements into Ellicott's
+mills, near Baltimore, where 325 barrels of flour were made per day,
+was calculated to have saved nearly $5,000 per year in cost of labor,
+and over $30,000 by increasing the production. He wrote "The Young
+Steam-Engineer's Guide," and a work which remained standard many years
+after his death, "The Young Millwright's Guide." Less fortunate than
+his transatlantic rival, he was nevertheless equally deserving of
+fame. He has sometimes been called "The Watt of America."
+
+The application of steam to locomotion on the common road was much
+more successful in Great Britain than in the United States. As early
+as 1786, William Symmington, subsequently more successful in his
+efforts to introduce steam for marine propulsion, assisted by his
+father, made a working model of a steam-carriage, which did not,
+however, lead to important results.
+
+In 1802, Richard Trevithick, a pupil of Murdoch's, who afterward
+became well known in connection with the introduction of railroads,
+made a model steam-carriage, which was patented in the same year. The
+model may still be seen in the Patent Museum at South Kensington.[46]
+
+  [46] _See_ "Life of Trevithick."
+
+In this engine, high-pressure steam was employed, and the condenser
+was dispensed with. The boiler was of the form devised by Evans, and
+was subsequently generally used in Cornwall, where it was called the
+"Trevithick Boiler." The engine had but one cylinder, and the
+piston-rod drove a "cross-tail," working in guides, which was
+connected with a "cross-head" on the opposite side of the shaft by two
+"side-rods." The connecting-rod was attached to the cross-head and the
+crank, "returning" toward the cylinder as the shaft lay between the
+latter and the cross-head. This was probably the first example of the
+now common "return connecting-rod engine." The connection between the
+crank-shaft and the wheels of the carriage was effected by gearing.
+The valve-gear and the feed-pumps were worked from the engine-shaft.
+The inventor proposed to secure his wheels against slipping by
+projecting bolts, when necessary, through the rim of the wheel into
+the ground. The first carriage of full size was built by Trevithick
+and Vivian at Camborne, in 1803, and, after trial, was taken to
+London, where it was exhibited to the public. _En route_, it was
+driven by its own engines to Plymouth, 90 miles from Camborne, and
+then shipped by water. It is not known whether the inventor lost faith
+in his invention; but he very soon dismantled the machine, sold the
+engine and carriage separately, and returned to Cornwall, where he
+soon began work on a railroad-locomotive.
+
+In 1821, Julius Griffiths, of Brompton, Middlesex, England, patented a
+steam-carriage for the transportation of passengers on the highway.
+His first road-locomotive was built in the same year by Joseph Bramah,
+one of the ablest mechanics of his time. The frame of the carriage
+carried a large double coach-body between the two axles, and the
+machinery was mounted over and behind the rear axle. One man was
+stationed on a rear platform, to manage the engine and to attend to
+the fire, and another, stationed in front of the body of the coach,
+handled the steering-wheel. The boiler was composed of horizontal
+water-tubes and steam-tubes, the latter being so situated as to
+receive heat from the furnace-gases _en route_ to the chimney, and
+thus to act as a superheater. The wheels were driven, by means of
+intermediate gearing, by two steam-engines, which, with their
+attachments, were suspended on helical springs, to prevent injury by
+jars and shocks. An air-surface condenser was used, consisting of
+flattened thin metal tubes, cooled by the contact of the external air,
+and discharging the water of condensation, as it accumulated within
+them, into a feed-pump, which, in turn, forced it into the lowest row
+of tubes in the boiler.
+
+The boiler did not prove large enough for continuous work; but the
+carriage was used experimentally, now and then, for a number of years.
+
+During the succeeding ten years the adaptation of the steam-engine to
+land-transportation continued to attract more and more attention, and
+experimental road-engines were built with steadily-increasing
+frequency. The defects of these engines revealing themselves on trial,
+they were one by one remedied, and the road-locomotive gradually
+assumed a shape which was mechanically satisfactory. Their final
+introduction into general use seemed at one time only a matter of
+time; their non-success was due to causes over which the legislator
+and the general public, and not the engineer, had control, as well as
+to the development of steam-transportation on a rival plan.
+
+In 1822, David Gordon patented a road-engine, but it is not known
+whether it was ever built. At about the same time, Mr. Goldsworthy
+Gurney, who subsequently took an active part in their introduction,
+stated, in his lectures, that "elementary power is capable of being
+applied to propel carriages along common roads with great political
+advantage, and the floating knowledge of the day places the object
+within reach." He made an ammonia-engine--probably the first ever
+made--and worked it so successfully, that he made use of it in driving
+a little locomotive.
+
+Two years later, Gordon patented a curious arrangement, which,
+however, had been proposed twelve years earlier by Brunton, and was
+again proposed afterward by Gurney, and others. This consisted in
+fitting to the engine a set of jointed legs, imitating, as nearly as
+the inventor could make them, the action of a horse's legs and feet.
+Such an arrangement was actually experimented with until it was found
+that they could not be made to work satisfactorily, when it was also
+found that they were not needed.
+
+During the same season, Burstall & Hill made a steam-carriage, and
+made many unsuccessful attempts to introduce their plan. The engine
+used was like that of Evans, except that the steam-cylinder was placed
+at the end of the beam, and the crank-shaft under the middle. The
+front and rear wheels were connected by a longitudinal shaft and bevel
+gearing. The boiler was found to have the usual defect, and would only
+supply steam for a speed of three or four miles an hour. The result
+was a costly failure. W. H. James, of London, in 1824-'25, proposed
+several devices for placing the working parts, as well as the body of
+the carriage, on springs, without interfering with their operation,
+and the Messrs. Seaward patented similar devices. Samuel Brown, in
+1826, introduced a gas-engine, in which the piston was driven by the
+pressure produced by the combustion of gas, and a vacuum was secured
+by the condensation of the resulting vapor. Brown built a locomotive
+which he propelled by this engine. He ascended Shooter's Hill, near
+London, and the principal cause of his ultimate failure seems to have
+been the cost of operating the engine.
+
+From this date forward, during several years, a number of inventors
+and mechanics seem to have devoted their whole time to this promising
+scheme. Among them, Burstall & Hill, Gurney, Ogle & Summers, Sir
+Charles Dance, and Walter Hancock, were most successful.
+
+Gurney, in the year 1827, built a steam-carriage, which he kept at
+work nearly two years in and about London, and sometimes making long
+journeys. On one occasion he made the journey from Meksham to Cranford
+Bridge, a distance of 85 miles, in 10 hours, including all stops. He
+used the mechanical legs previously adopted by Brunton and by Gordon,
+but omitted this rude device in those engines subsequently built.
+
+Gurney's engine of 1828 is of interest to the engineer as exhibiting a
+very excellent arrangement of machinery, and as having one of the
+earliest of "sectional boilers." The latter was of peculiar form, and
+differed greatly in design from the sectional boiler invented a
+quarter of a century earlier by John Stevens, in the United States.
+
+[Illustration: FIG. 48.--Gurney's Steam-Carriage.]
+
+In the sketch (Fig. 48) this boiler is seen at the right. It was
+composed of bent [<]-shaped tubes, _a a_, connected to two cylinders,
+_b b_, the upper one of which was a steam-chamber. Vertical tubes
+connected these two chambers, and permitted a complete and regular
+circulation of the water. A separate reservoir, called a separator,
+_d_, was connected with these chambers by pipes, as shown. From the
+top of this separator a steam-pipe, _e e e_, conveyed steam to the
+engine-cylinders at _f_. The cranks, _g_, on the rear axle were turned
+by the engines, and the eccentric, _h_, on the axle drove the
+valve-gearing and the valve, _i_. The link, _k l_, being moved by a
+line, _l l_, led from the driver's seat, the carriage was started,
+stopped, or reversed, by throwing the upper end of the link into gear
+with the valve-stem, by setting the link midway between its upper and
+lower positions, or by raising it until the lower end, coming into
+action on the valve-stem, produced a reverse motion of the valve. The
+pin on which this link vibrated is seen at the centre of its
+elliptical strap. The throttle-valve, _o_, by which the supply of
+steam to the engine was adjusted, was worked by the lever, _n_. The
+exhaust-pipe, _p_, led to the tank, _q_, and the uncondensed vapor
+passed to the chimney, _s s_, by the pipe, _r r_. The force-pump, _u_,
+taking feed-water from the tank, _t_, supplied it to the boiler by the
+pipe, _x x x_, which, _en route_, was coiled up to form a "heater"
+directly above the boiler. The supply was regulated by the cock, _y_.
+The attendant had a seat at _z_. A blast-apparatus, 1, was driven by
+an independent engine, 2 3, and produced a forced blast, which was led
+to the boiler-furnace through the air-duct, 5 5; 4 4 represents the
+steam-pipe to the little blowing-engine. The steering-wheel, 6, was
+directed by a lever, 7, and the change of direction of the perch, 8,
+which turned about a king-bolt at 9, gave the desired direction to the
+forward wheels and to the carriage.
+
+This seems to have been one of the best designs brought out at that
+time. The boiler, built to carry 70 pounds, was safe and strong, and
+was tested up to 800 pounds pressure. A forced draught was provided.
+The engines were well placed, and of good design. The valve was
+arranged to work the steam with expansion from half-stroke. The
+feed-water was heated, and the steam slightly superheated. The boiler
+here used has been since reproduced under new names by later
+inventors, and is still used with satisfactory results. Modifications
+of the "pipe-boiler" were made by several other makers of
+steam-carriages also. Anderson & James made their boilers of
+lap-welded iron tubes of one inch internal diameter and one-fifth inch
+thick, and claimed for them perfect safety. Such tubes should have
+sufficient strength to sustain a pressure of 20,000 pounds per square
+inch. If made of such good iron as the makers claimed to have put into
+them, "which worked like lead," they would, as was also claimed, when
+ruptured, open by tearing, and discharge their contents without
+producing the usual disastrous consequences of boiler explosions.
+
+The primary principle of the sectional boiler was then well
+understood. The boilers of Ogle & Summers were made up of pairs of
+upright tubes, set one within the other, the intervening space being
+filled with water and steam, and the flame passing through the inner
+and around the outer tube of each pair.
+
+One of the engines of Sir James Anderson and W. H. James was built in
+1829. It had two 3-1/2-inch steam-cylinders, driving the rear wheels
+independently. In James's earlier plan of 1824-'25, a pair of
+cylinders was attached to each of the two halves into which the rear
+axle was divided, and were arranged to drive cranks set at
+right-angles with each other. The later machine weighed 3 tons, and
+carried 15 passengers, on a rough graveled road across the Epping
+Forest, at the rate of from 12 to 15 miles per hour. Steam was carried
+at 300 pounds. Several tubes gave way in the welds, but the carriage
+returned, carrying 24 passengers at the rate of 7 miles per hour. On a
+later trial, with new boilers, the carriage again made 15 miles per
+hour. It was, however, subject to frequent accidents, and was finally
+withdrawn.
+
+WALTER HANCOCK was the most successful and persevering of all those
+who attempted the introduction of steam on the common road. He had, in
+1827, patented a boiler of such peculiar form, that it deserves
+description. It consisted of a collection of flat chambers, of which
+the walls were of boiler-plate. These chambers were arranged side by
+side, and connected laterally by tubes and stays, and all were
+connected by short vertical tubes to a horizontal large pipe placed
+across the top of the boiler-casing, and serving as a steam-drum or
+separator. This earliest of "sheet flue-boilers" did excellent
+service on Hancock's steam-carriages, where experience showed that
+there was little or no danger of disruptive explosions.
+
+Hancock's first steam-carriage was mounted on three wheels, the
+leading-wheel arranged to swivel on a king-bolt, and driven by a pair
+of oscillating cylinders connected with its axle, which was "cranked"
+for the purpose. The engines turned with the steering-wheel. This
+carriage was by no means satisfactory, but it was used for a long
+time, and traveled many hundreds of miles without once failing to do
+the work assigned it.
+
+By this time there were a half-dozen steam-carriages under
+construction for Hancock, for Ogle & Summers, and for Sir Charles
+Dance.
+
+In 1831, Hancock placed a new carriage on a route between London and
+Stratford, where it ran regularly for hire. Dance, in the same season,
+started another on the line between Cheltenham and Gloucester, where
+it ran from February 21st to June 22d, traveling 3,500 miles and
+carrying 3,000 passengers, running the 9 miles in 55 minutes usually,
+and sometimes in three-quarters of an hour, and never meeting with an
+accident, except the breakage of an axle in running over heaps of
+stones which had been purposely placed on the road by enemies of the
+new system of transportation. Ogle & Summers's carriage attained a
+speed, as testified by Ogle before a committee of the House of
+Commons, of from 32 to 35 miles an hour, and on a rising grade, near
+Southampton, at 24-1/2 miles per hour. They carried 250 pounds of
+steam, ran 800 miles, and met with no accident. Colonel Macerone, in
+1833, ran a steam-carriage of his own design from London to Windsor
+and back, with 11 passengers, a distance of 23-1/2 miles, in 2 hours.
+Sir Charles Dance, in the same year, ran his carriage 16 miles an
+hour, and made long excursions at the rate of 9 miles an hour. Still
+another experimenter, Heaton, ascended Lickey Hill, between Worcester
+and Birmingham, on gradients of one in eight and one in nine, in
+places; this was considered one of the worst pieces of road in
+England. The carriage towed a coach containing 20 passengers.
+
+Of all these, and many others, Hancock, however, had most marked
+success. His coach, called the "Infant," which was set at work in
+February, 1831, was, a year later, plying between London "City" and
+Paddington. Another, called the "Era," was built for the London and
+Greenwich Steam-Carriage Company, which was mechanically a success.
+The company, however, was financially unsuccessful. In October, 1832,
+the "Infant" ran to Brighton from London, carrying a party of 11, at
+the rate of 9 miles per hour, ascending Redhill at a speed of 5 miles.
+They steamed 38 miles the first day, stopping at night at Hazledean,
+and reached Brighton next day, running 11 miles per hour. Returning
+with 15 passengers, the coach ran 1 mile in less than 4 minutes, and
+made 10 miles in 55 minutes. A run from Stratford to Brighton was made
+in less than 10 hours, at an average speed of 12 miles an hour running
+time, the actual running time being less than 6 hours. The next year
+another carriage, the "Enterprise," was put on the road to Paddington
+by Hancock for another company, and ran regularly over two weeks; but
+this company was also unsuccessful. In the summer of 1833 he brought
+out still another steam-coach, the "Autopsy" (Fig. 49), which he ran
+to Brighton, and then, returning to London, man[oe]uvred the carriage
+in the crowded streets without difficulty or accident. He went about
+the streets of London at all times, and without hesitation. The coach
+next ran between Finsbury Square and Pentonville regularly for four
+weeks, without accident or delay. In the sketch, a part of the side is
+broken away to show the machinery. The boiler, _A B_, supplies steam
+through the steam-pipe, _H K_, to the steam-engine, _C D_, which is
+coupled to the crank-shaft, _F_. _E_ is the feed-pump. The rear axle
+is turned by the endless chain seen connecting it with the
+engine-shaft, and the rear wheels, _S_, are thus driven. A blower,
+_T_, gives a forced draught. The driver sits at _M_, steering by the
+wheel, _N_, which is coupled to the larger wheel, _P_, and thus turns
+the forward axle into any desired position. In 1834, Hancock built a
+steam "drag" on an Austrian order, which, carrying 10 persons and
+towing a coach containing 6 passengers, was driven through the city
+beyond Islington, making 14 miles an hour on a level, and 8 miles or
+more on rising ground. In the same year he built the "Era," and, in
+August, put the "Autopsy" on with it, to make a steam-line to
+Paddington. These coaches ran until the end of November, carrying
+4,000 passengers, at a usual rate of speed of 12 miles per hour. He
+then sent the "Era" to Dublin, where, on one occasion, it ran 18 miles
+per hour.
+
+[Illustration: FIG. 49.--Hancock's "Autopsy," 1833.]
+
+In 1835 a large carriage, the "Erin," was completed, which was
+intended to carry 20 passengers. It towed three omnibuses and a
+stage-coach, with 50 passengers, on a level road, at the speed of 10
+miles an hour. It drew an omnibus with 18 passengers through
+Whitehall, Charing Cross, and Regent Street, and out to Brentford,
+running 14 miles an hour. It ran also to Reading, making 38 miles,
+with the same load, in 3 hours and 8 minutes running time. The stops
+_en route_ occupied a half-hour. The same carriage made 75 miles to
+Marlborough in 7-1/2 hours running time, stopping 4-1/2 hours on the
+road, in consequence of having left the tender and supplies behind.
+
+In May, 1836, Hancock put all his carriages on the Paddington road,
+and ran regularly for over five months, running 4,200 miles in 525
+trips to Islington, 143 to Paddington, and 44 to Stratford, passing
+through the city over 200 times. The carriages averaged 5 hours and 17
+or 18 minutes daily running time. A light steam-phaeton, built in
+1838, for his own use, made 20 miles an hour, and was driven about the
+city, and among horses and carriages, without causing annoyance or
+danger. Its usual speed was about 10 miles an hour. Altogether,
+Hancock built nine steam-carriages, capable of carrying 116 passengers
+in addition to the regular attendants.[47]
+
+  [47] For a detailed account of the progress of steam on the highway,
+  _see_ "Steam on Common Roads," etc., by Young, Holley, & Fisher,
+  London, 1861.
+
+In December, 1833, about 20 steam-carriages and traction road-engines
+were running, or were in course of construction, in and near London.
+In our own country, the roughness of roads discouraged inventors;
+and in Great Britain even, the successful introduction of
+road-locomotives, which seemed at one time almost an accomplished
+fact, finally met with so many obstacles, that even Hancock, the most
+ingenious, persistent, and successful constructor, gave up in despair.
+Hostile legislation procured by opposing interests, and the rapid
+progress of steam-locomotion on railroads, caused this result.
+
+In consequence of this interruption of experiment, almost nothing was
+done during the succeeding quarter of a century, and it is only within
+a few years that anything like a business success has been founded
+upon the construction of road-locomotives, although the scheme seems
+to have been at no time entirely given up.
+
+The opposition of coach-proprietors, and of all classes having an
+interest in the old lines of coaches, was most determined, and the
+feeling evinced by them was intensely bitter; but the advocates of the
+new system of transportation were equally determined and persevering,
+and, having right on their side, and the pecuniary advantage of the
+public as their object, they would probably have succeeded ultimately,
+except for the introduction of the still better method of
+transportation by rail.
+
+In the summer of 1831, when the war between the two parties was at its
+height, a committee of the British House of Commons made a very
+complete investigation of the subject. This committee reported that
+they had become convinced that "the substitution of inanimate for
+animal power, in draught on common roads, is one of the most important
+improvements in the means of internal communication ever introduced."
+They considered its practicability to have been "fully established,"
+and predicted that its introduction would "take place more or less
+rapidly, in proportion as the attention of scientific men shall be
+drawn, by public encouragement, to further improvement." The success
+of the system had, as they stated, been retarded by prejudice, adverse
+interests, and prohibitory tolls; and the committee remark: "When we
+consider that these trials have been made under the most unfavorable
+circumstances, at great expense, in total uncertainty, without any of
+those guides which experience has given to other branches of
+engineering; that those engaged in making them are persons looking
+solely to their own interests, and not theorists attempting the
+perfection of ingenious models; when we find them convinced, after
+long experience, that they are introducing such a mode of conveyance
+as shall tempt the public, by its superior advantages, from the use of
+the admirable lines of coaches which have been generally established,
+it surely cannot be contended that the introduction of steam-carriages
+on common roads is, as yet, an uncertain experiment, unworthy of
+legislative attention."
+
+Farey, one of the most distinguished mechanical engineers of the
+time, testified that he considered the practicability of such a system
+as fully established, and that the result would be its general
+adoption. Gurney had run his carriage between 20 and 30 miles an hour;
+Hancock could sustain a speed of 10 miles; Ogle had run his coach 32
+to 35 miles an hour, and ascended a hill rising 1 in 6 at the speed of
+24-1/2 miles. Summers had traveled up a hill having a gradient of 1 in
+12, with 19 passengers, at the rate of speed of 15 miles per hour; he
+had run 4-1/2 hours at 30 miles an hour. Farey thought that
+steam-coaches would be found to cost one-third as much as the
+stage-coaches in use. The steam-carriages were reported to be safer
+than those drawn by horses, and far more manageable; and the
+construction of boilers adopted--the "sectional" boiler, as it is now
+called--completely insured against injury by explosion, and the
+dangers and inconveniences arising from the frightening of horses had
+proved to be largely imaginary. The wear and tear of roads were found
+to be less than with horses, while with broad wheel-tires the
+carriages acted beneficially as road-rollers. The committee finally
+concluded:
+
+"1. That carriages can be propelled by steam on common roads at an
+average rate of 10 miles per hour.
+
+"2. That at this rate they have conveyed upward of 14 passengers.
+
+"3. That their weight, including engine, fuel, water, and attendants,
+may be under three tons.
+
+"4. That they can ascend and descend hills of considerable inclination
+with facility and safety.
+
+"5. That they are perfectly safe for passengers.
+
+"6. That they are not (or need not be, if properly constructed)
+nuisances to the public.
+
+"7. That they will become a speedier and cheaper mode of conveyance
+than carriages drawn by horses.
+
+"8. That, as they admit of greater breadth of tire than other
+carriages, and as the roads are not acted on so injuriously as by the
+feet of horses in common draught, such carriages will cause less wear
+of roads than coaches drawn by horses.
+
+"9. That rates of toll have been imposed on steam-carriages, which
+would prohibit their being used on several lines of road, were such
+charges permitted to remain unaltered."
+
+THE RAILROAD, which now, by the adaptation of steam to the propulsion
+of its carriages, became the successful rival of the system of
+transportation of which an account has just been given, was not a new
+device. It, like all other important changes of method and great
+inventions, had been growing into form for ages. The ancients were
+accustomed to lay down blocks of stone as a way upon which their
+heavily-loaded wagons could be drawn with less resistance than on the
+common road. This practice was gradually so modified as to result in
+the adoption of the now universally-practised methods of paving and
+road-making. The old tracks, bearing the marks of heavy traffic, are
+still seen in the streets of the unearthed city of Pompeii.
+
+In the early days of mining in Great Britain, the coal or the ore was
+carried from the mine to the vessel in which it was to be embarked in
+sacks on the backs of horses. Later, the miners laid out wagon-roads,
+and used carts and wagons drawn by horses, and the roads were paved
+with stone along the lines traversed by the wheels of the vehicles.
+Still later (about 1630), heavy planks or squared timber took the
+place of the stone, and were introduced into the north of England by a
+gentleman of the name of Beaumont, who had transferred his property
+there from the south. A half century later, the system had become
+generally introduced. By the end of the eighteenth century the
+construction of these "tram-ways" had become well-understood, and the
+economy which justified the expenditure of considerable amounts of
+money in making cuts and in filling, to bring the road to a uniform
+grade, had become well-recognized. Arthur Young, writing at this time,
+says the coal wagon-roads were "great works, carried over all sorts
+of inequalities of ground, so far as the distance of nine or ten
+miles," and that, on these tram-ways of timber, "one horse is able to
+draw, and that with ease, fifty or sixty bushels of coals." The
+wagon-wheels were of cast-iron, and made with grooved rims, which
+fitted the rounded tops of the wooden rails. But these wooden rails
+were found subject to rapid decay, and at Whitehaven, in 1738, they
+were protected from wear by cast-iron plates laid upon them, and this
+improvement rapidly became known and adopted. A tram-road, laid down
+at Sheffield for the Duke of Norfolk, in 1776, was made by laying
+angle-bars of cast-iron on longitudinal sleepers of timber; another,
+built by William Jessup in Leicestershire, in 1789, had an edge-rail,
+and the wheels were made with flanges, like those used to-day. The
+coned "tread" of the wheel, which prevents wear of flanges and reduces
+resistance, was the invention of James Wright, of Columbia, Pa., 40
+years later. The modern railroad was simply the result of this gradual
+improvement of the permanent way, and the adaptation of the
+steam-engine to the propulsion of its wagons.
+
+At the beginning of the nineteenth century, therefore, the
+steam-engine had been given a form which permitted its use, and the
+railroad had been so far perfected that there were no difficulties to
+be anticipated in the construction of the permanent way, and inventors
+were gradually preparing, as has been seen, to combine these two
+principal elements into one system. Railroads had been introduced in
+all parts of Great Britain, some of them of considerable length, and
+involving the interests of so many private individuals that they were
+necessarily constructed under the authorization of legal enactments.
+In the year 1805 the Merstham Railway was opened to traffic, and it is
+stated that on that occasion one horse drew a train of 12 wagons,
+carrying 38 tons of stone, on a "down gradient" of 1 in 120, at the
+rate of 6 miles per hour.
+
+[Illustration: Richard Trevithick.]
+
+[Illustration: FIG. 50.--Trevithick's Locomotive, 1804.]
+
+RICHARD TREVITHICK was the first engineer to apply steam-power to the
+haulage of loads on the railroad. Trevithick was a Cornishman by
+birth, a native of Redruth. He was naturally a skillful mechanic, and
+was placed by his father with Watt's assistant, Murdoch, who was
+superintending the erection of pumping-engines in Cornwall; and from
+that ingenious and accomplished engineer young Trevithick probably
+acquired both the skill and the knowledge which, with his native
+talent, enterprise, and industry, enabled him to accomplish the work
+which has made him famous. He was soon intrusted with the erection and
+management of large pumping-engines, and subsequently went into the
+business of constructing steam-engines with another engineer, Edward
+Bull, who took an active part, with the Hornblowers and others, in
+opposing the Boulton & Watt patents. The termination of the suits
+which established the validity of Watt's patent put an end to their
+business, and Trevithick looked about for other work, and, not long
+after, entered into partnership with a relative, Andrew Vivian, who
+was also a skillful mechanic; they together designed and patented the
+steam-carriage already referred to. Its success was sufficiently
+satisfactory to awaken strong confidence of a perfect success on the
+now common tram-roads; and Trevithick, in February, 1804, had
+completed a "locomotive" engine to work on the Welsh Pen-y-darran
+road. This engine (Fig. 50) had a cylindrical flue-boiler, _A_, like
+that designed by Oliver Evans, and a single steam-cylinder, _B_, set
+vertically into the steam-space of the boiler, and driving the
+outside cranks, _L_, on the rear axle of the engine by very long
+connecting-rods, _D_, attached to its cross-head at _E_. The
+guide-bars, _I_, were stayed by braces leading to the opposite end of
+the boiler. No attempt was made to condense the exhaust-steam, which
+was discharged into the smoke-pipe. The pressure of steam adopted was
+40 pounds per square inch; but Trevithick had already made a number of
+non-condensing engines on which he carried from 50 to 145 pounds
+pressure.
+
+In the year 1808, Trevithick built a railroad in London, on what was
+known later as Torrington Square, or Euston Square, and set at work a
+steam-carriage, which he called "Catch-me-who-can." This was a very
+plain and simple machine. The steam-cylinder was set vertically in the
+after-end of the boiler, and the cross-head was connected to two rods,
+one on either side, driving the hind pair of wheels. The exhaust-steam
+entered the chimney, aiding the draught. This engine, weighing about
+10 tons, made from 12 to 15 miles an hour on the circular railway in
+London, and was said by its builder to be capable of making 20 miles
+an hour. The engine was finally thrown from the track, after some
+weeks of work, by the breaking of a rail, and, Trevithick's funds
+having been expended, it was never replaced. This engine had a
+steam-cylinder 14-1/2 inches in diameter, and a stroke of piston of 4
+feet. Trevithick used no device to aid the friction of the wheels on
+the rails in giving pulling-power, and seems to have understood that
+none was needed. This plan of working a locomotive-engine without such
+complications as had been proposed by other engineers was, however,
+subsequently patented, in 1813, by Blackett & Hedley. The latter was
+at one time Trevithick's agent, and was director of Wylam Colliery, of
+which Mr. Blackett was proprietor.
+
+Trevithick applied his high-pressure non-conducting engine not only to
+locomotives, but to every purpose that opportunity offered him. He put
+one into the Tredegar Iron-Works, to drive the puddle-train, in 1801.
+This engine had a steam-cylinder 28 inches in diameter, and 6 feet
+stroke of piston; a boiler of cast-iron, 6-3/4 feet in diameter and 20
+feet long, with a wrought-iron internal tube, 3 feet in diameter at
+the furnace-end and 24 inches beyond the furnace. The steam-pressure
+ranged from 50 to 100 pounds per square inch. The valve was a four-way
+cock. The exhaust-steam was carried into the chimney, passing through
+a feed-water heater _en route_. This engine was taken down in
+1856.[48]
+
+  [48] "Life of Trevithick."
+
+In 1803, Trevithick applied his engine to driving rock-drills, and
+three years later made a large contract with the Trinity Board for
+dredging in the Thames, and constructed steam dredging-machines for
+the work, of the form which is still most generally used in Great
+Britain, although rarely seen in the United States--the
+"chain-and-bucket dredger."
+
+A little later, Trevithick was engaged upon the first and unsuccessful
+attempt to carry a tunnel under the Thames, at London; but no sooner
+had that costly scheme been given up, than he returned to his favorite
+pursuits, and continued his work on interrupted schemes for
+ship-propulsion. Trevithick at last left England, spent some years in
+South America, and finally returned home and died in extreme poverty,
+April, 1833, at the age of sixty-two, without having succeeded in
+accomplishing the general introduction of any of his inventions.
+
+Trevithick was characteristically an inventor of the typical sort. He
+invented many valuable devices, but brought but few into even
+experimental use, and reaped little advantage from any of them. He was
+ingenious, a thorough mechanic, bold, active, and indefatigable; but
+his lack of persistence made his whole life, as Smiles has said, "but
+a series of beginnings."
+
+It is at about this period that we find evidence of the intelligent
+labors of another of our own countrymen--one who, in consequence of
+the unobtrusive manner in which his work was done, has never received
+the full credit to which he is entitled.
+
+COLONEL JOHN STEVENS, of Hoboken, as he is generally called, was born
+in the city of New York, in 1749; but throughout his business-life he
+was a resident of New Jersey.
+
+[Illustration: Colonel John Stevens.]
+
+His attention is said to have been first called to the application of
+steam-power by seeing the experiments of John Fitch with his steamer
+on the Delaware, and he at once devoted himself to the introduction of
+steam-navigation with characteristic energy, and with a success that
+will be indicated when we come to the consideration of that subject.
+
+But this far-sighted engineer and statesman saw plainly the
+importance of applying the steam-engine to land-transportation as well
+as to navigation; and not only that, but he saw with equal
+distinctness the importance of a well-devised and carefully-prosecuted
+scheme of internal communication by a complete system of railroads. In
+1812 he published a pamphlet containing "Documents tending to prove
+the superior advantages of Railways and Steam-Carriages over
+Canal-Navigation."[49] At this time, the only locomotive in the world
+was that of Trevithick and Vivian, at Merthyr Tydvil, and the railroad
+itself had not grown beyond the old wooden tram-roads of the
+collieries. Yet Colonel Stevens says, in this paper: "I can see
+nothing to hinder a steam-carriage moving on its ways with a velocity
+of 100 miles an hour;" adding, in a foot-note: "This astonishing
+velocity is considered here merely possible. It is probable that it
+may not, in practise, be convenient to exceed 20 or 30 miles per hour.
+Actual experiment can only determine this matter, and I should not be
+surprised at seeing steam-carriages propelled at the rate of 40 or 50
+miles an hour."
+
+  [49] Printed by T. & J. Swords, 160 Pearl Street, New York, 1812.
+
+At a yet earlier date he had addressed a memoir to the proper
+authorities, urging his plans for railroads. He proposed rails of
+timber, protected, when necessary, by iron plates, or to be made
+wholly of iron; the car-wheels were to be of cast-iron, with inside
+flanges to keep them on the track. The steam-engine was to be driven
+by steam of 50 pounds pressure and upward, and to be non-condensing.
+
+Answering the objections of Robert R. Livingston and of the State
+Commissioners of New York, he goes further into details. He gives 500
+to 1,000 pounds as the maximum weight to be placed on each wheel;
+shows that the trains, or "suits of carriages," as he calls them, will
+make their journeys with as much certainty and celerity in the darkest
+night as in the light of day; shows that the grades of proposed roads
+would offer but little resistance; and places the whole subject before
+the public with such accuracy of statement and such evident
+appreciation of its true value, that every one who reads this
+remarkable document will agree fully with President Charles King, who
+said[50] that "whosoever shall attentively read this pamphlet, will
+perceive that the political, financial, commercial, and military
+aspects of this great question were all present to Colonel Stevens's
+mind, and that he felt that he was fulfilling a patriotic duty when he
+placed at the disposal of his native country these fruits of his
+genius. The offering was not then accepted. The 'Thinker' was ahead of
+his age; but it is grateful to know that he lived to see his projects
+carried out, though not by the Government, and that, before he
+finally, in 1838, closed his eyes in death, at the great age of
+eighty-nine, he could justly feel assured that the name of Stevens, in
+his own person and in that of his sons, was imperishably enrolled
+among those which a grateful country will cherish."
+
+  [50] "Progress of the City of New York."
+
+Without having made any one superlatively great improvement in the
+mechanism of the steam-engine, like that which gave Watt his
+fame--without having the honor even of being the first to
+propose the propulsion of vessels by the modern steam-engine, or
+steam-transportation on land--he exhibited a far better knowledge of
+the science and the art of engineering than any man of his time; and
+he entertained and urged more advanced opinions and more statesmanlike
+views in relation to the economical importance of the improvement and
+the application of the steam-engine, both on land and water, than seem
+to be attributable to any other leading engineer of that time.
+
+Says Dr. King: "Who can estimate if, at that day, acting upon the
+well-considered suggestion of President Madison, 'of the signal
+advantages to be derived to the United States from a general system of
+internal communication and conveyance,' Congress had entertained
+Colonel Stevens's proposal, and, after verifying by actual experiment
+upon a small scale the accuracy of his plan, had organized such a
+'general system of internal communication and conveyance;' who can
+begin to estimate the inappreciable benefits that would have resulted
+therefrom to the comfort, the wealth, the power, and, above all, to
+the absolutely impregnable union of our great Republic and all its
+component parts? All this Colonel Stevens embraced in his views, for
+he was a statesman as well as an experimental philosopher; and whoever
+shall attentively read his pamphlet, will perceive that the political,
+financial, commercial, and military aspects of this great question
+were all present to his mind, and he felt that he was fulfilling a
+patriotic duty when he placed at the disposal of his native country
+these fruits of his genius."
+
+WILLIAM HEDLEY, who has already been referred to, seems to have been
+the first to show, by carefully-conducted experiment, how far the
+adhesion of the wheels of the locomotive-engine could be relied upon
+for hauling-power in the transportation of loads.
+
+His employer, Blackett, had applied to Trevithick for a
+locomotive-engine to haul coal-trains at the Wylam collieries; but
+Trevithick was unable, or was disinclined, to build him one, and in
+October, 1812, Hedley was authorized to attempt the construction of an
+engine. It was at about this time that Blenkinsop (1811) was trying
+the toothed rail or rack, the Messrs. Chapman (December, 1812) were
+experimenting with a towing-chain, and (May, 1813) Brunton with
+movable legs.
+
+Hedley, who had known of the success met with in the experiments of
+Trevithick with smooth wheels hauling loads of considerable weight, in
+Cornwall, was confident that equal success might be expected in the
+north-country, and built a carriage to be moved by men stationed at
+four handles, by which its wheels were turned.
+
+This carriage was loaded with heavy masses of iron, and attached to
+trains of coal-wagons on the railway. By repeated experiment, varying
+the weight of the traction-carriage and the load hauled, Hedley
+ascertained the proportion of the weight required for adhesion to that
+of the loads drawn. It was thus conclusively proven that the weight of
+his proposed locomotive-engine would be sufficient to give the
+pulling-power necessary for the propulsion of the coal-trains which it
+was to haul.
+
+When the wheels slipped in consequence of the presence of grease,
+frost, or moisture on the rail, Hedley proposed to sprinkle ashes on
+the track, as sand is now distributed from the sand-box of the modern
+engine. This was in October, 1812.
+
+Hedley now went to work building an engine with smooth wheels, and
+patented his design March 13, 1813, a month after he had put his
+engine at work. The locomotive had a cast-iron boiler, and a single
+steam-cylinder 6 inches in diameter, with a small fly-wheel. This
+engine had too small a boiler, and he soon after built a larger
+engine, with a return-flue boiler made of wrought-iron. This hauled 8
+loaded coal-wagons 5 miles an hour at first, and a little later 10,
+doing the work of 10 horses. The steam-pressure was carried at about
+50 pounds, and the exhaust, led into the chimney, where the pipe was
+turned upward, thus secured a blast of considerable intensity in its
+small chimney. Hedley also contracted the opening of the exhaust-pipe
+to intensify the blast, and was subjected to some annoyance by
+proprietors of lands along his railway, who were irritated by the
+burning of their grass and hedges, which were set on fire by the
+sparks thrown out of the chimney of the locomotive. The cost of
+Hedley's experiment was defrayed by Mr. Blackett.
+
+Subsequently, Hedley mounted his engine on eight wheels, the
+four-wheeled engines having been frequently stopped by breaking the
+light rails then in use. Hedley's engines continued in use at the
+Wylam collieries many years. The second engine was removed in 1862,
+and is now preserved at the South Kensington Museum, London.
+
+GEORGE STEPHENSON, to whom is generally accorded the honor of having
+first made the locomotive-engine a success, built his first engine at
+Killingworth, England, in 1814.
+
+[Illustration: George Stephenson.]
+
+At this time Stephenson was by no means alone in the field, for the
+idea of applying the steam-engine to driving carriages on common roads
+and on railroads was beginning, as has been seen, to attract
+considerable attention. Stephenson, however, combined, in a very
+fortunate degree, the advantages of great natural inventive talent and
+an excellent mechanical training, reminding one strongly of James
+Watt. Indeed, Stephenson's portrait bears some resemblance to that of
+the earlier great inventor.
+
+George Stephenson was born June 9, 1781, at Wylam, near
+Newcastle-upon-Tyne, and was the son of a "north-country miner." When
+still a child, he exhibited great mechanical talent and unusual love
+of study. When set at work about the mines, his attention to duty and
+his intelligence obtained for him rapid promotion, until, when but
+seventeen years of age, he was made engineer, and took charge of the
+pumping-engine at which his father was fireman.
+
+When a mere child, and employed as a herd-boy, he amused himself
+making model engines in clay, and, as he grew older, never lost an
+opportunity to learn the construction and management of machinery.
+After having been employed at Newburn and Callerton, where he first
+became "engine-man," he began to study with greater interest than ever
+the various steam-engines which were then in use; and both the
+Newcomen engine and the Watt pumping-engine were soon thoroughly
+understood by him. After having become a brakeman, he removed to
+Willington Quay, where he married, and commenced his wedded life on 18
+or 20 shillings per week. It was here that he became an intimate
+friend of the distinguished William Fairbairn, who was then working as
+an apprentice at the Percy Main Colliery, near by. The "father of the
+railroad" and the future President of the British Association were
+accustomed, at times, to "change works," and were frequently seen in
+consultation over their numerous projects. It was at Willington Quay
+that his son Robert, who afterward became a distinguished civil
+engineer, was born, October 16, 1803.
+
+In the following year Stephenson removed to Killingworth, and became
+brakeman at that colliery; but his wife soon died, and he gladly
+accepted an invitation to become engine-driver at a spinning-mill near
+Montrose, Scotland. At the end of a year he returned, on foot, to
+Killingworth with his savings (about £28), expended over one-half of
+the amount in paying his father's debts and in making his parents
+comfortable, and then returned to his old station as brakeman at the
+pit.
+
+Here he made some useful improvements in the arrangement of the
+machinery, and spent his spare hours in studying his engine and
+planning new machines. He a little later distinguished himself by
+altering and repairing an old Newcomen engine at the High Pit, which
+had failed to give satisfaction, making it thoroughly successful after
+three days' work. The engine cleared the pit, at which it had been
+vainly laboring a long time, in two days after Stephenson started it
+up.
+
+In the year 1812, Stephenson was made engine-wright of the
+Killingworth High Pit, receiving £100 a year, and it was made his duty
+to supervise the machinery of all the collieries under lease by the
+so-called "Grand Allies." It was here, and at this period, that he
+commenced a systematic course of self-improvement and the education of
+his son, and here he first began to be recognized as an inventor. He
+was full of life and something of a wag, and often made most amusing
+applications of his inventive powers: as when he placed the watch,
+which a comrade had brought him as out of repairs, in the oven "to
+cook," his quick eye having noted the fact that the difficulty arose
+simply from the clogging of the wheels by the oil, which had been
+congealed by cold.
+
+Smiles,[51] his biographer, describes his cottage as a perfect
+curiosity-shop, filled with models of engines, machines of various
+kinds, and novel apparatus. He connected the cradles of his neighbors'
+wives with the smoke-jacks in their chimneys, and thus relieved them
+from constant attendance upon their infants; he fished at night with a
+submarine lamp, which attracted the fish from all sides, and gave him
+wonderful luck; he also found time to give colloquial instruction to
+his fellow-workmen.
+
+  [51] "Lives of George and Robert Stephenson," by Samuel Smiles. New
+  York and London, 1868.
+
+He built a self-acting inclined plane for his pit, on which the
+wagons, descending loaded, drew up the empty trains; and made so many
+improvements at the Killingworth pit, that the number of horses
+employed underground was reduced from 100 to 16.
+
+Stephenson now had more liberty than when employed at the brakes, and,
+hearing of the experiments of Blackett and Hedley at Wylam, went over
+to their colliery to study their engine. He also went to Leeds to see
+the Blenkinsop engine draw, at a trial, 70 tons at the rate of 3 miles
+an hour, and expressed his opinion in the characteristic remark, "I
+think I could make a better engine than that to go upon legs." He very
+soon made the attempt.
+
+Having laid the subject before the proprietors of the lease under
+which the collieries were worked, and convinced Lord Ravensworth, the
+principal owner, of the advantages to be secured by the use of a
+"traveling engine," that nobleman advanced the money required.
+Stephenson at once commenced his first locomotive-engine, building it
+in the workshops at West Moor, assisted mainly by John Thirlwall, the
+colliery blacksmith, during the years 1813 and 1814, completing it in
+July of the latter year.
+
+This engine had a wrought-iron boiler 8 feet long and 2 feet 10 inches
+in diameter, with a single flue 20 inches in diameter. The cylinders
+were vertical, 8 inches in diameter and of 2 feet stroke of piston,
+set in the boiler, and driving a set of wheels which geared with each
+other and with other cogged wheels on the two driving-axles. A
+feed-water heater surrounded the base of the chimney. This engine drew
+30 tons on a rising gradient of 10 or 12 feet to the mile at the rate
+of 4 miles an hour. This engine proved in many respects defective, and
+the cost of its operation was found to be about as great as that of
+employing horse-power.
+
+Stephenson determined to build another engine on a somewhat different
+plan, and patented its design in February, 1815. It proved a much
+more efficient machine than the "Blücher," the first engine.
+
+[Illustration: FIG. 51.--Stephenson's Locomotive of 1815. Section.]
+
+This second engine (Fig. 51) was also fitted with two vertical
+cylinders, _C c_, but the connecting-rods were attached directly to
+the four driving-wheels, _W W´_. To permit the necessary freedom of
+motion, "ball-and-socket" joints were adopted, to unite the rods with
+the cross-heads, _R r_, and with the cranks, _R´ Y´_; and the two
+driving-axles were connected by an endless chain, _T t´_. The cranked
+axle and the outside connection of the wheels, as specified in the
+patent, were not used until afterward, it having been found impossible
+to get the cranked axles made. In this engine the forced draught
+obtained by the impulse of the exhaust-steam was adopted, doubling the
+power of the machine and permitting the use of coke as a fuel, and
+making it possible to adopt the multi-tubular boiler. Small
+steam-cylinders, _S S S_, took the weight of the engine and served as
+springs.
+
+It was at about this time that George Stephenson and Sir Humphry
+Davy, independently and almost simultaneously, invented the
+"safety-lamp," without which few mines of bituminous coal could to-day
+be worked. The former used small tubes, the latter fine wire gauze, to
+intercept the flame. Stephenson proved the efficiency of his lamp by
+going with it directly into the inflammable atmosphere of a dangerous
+mine, and repeatedly permitting the light to be extinguished when the
+lamp became surcharged with the explosive mixture which had so
+frequently proved fatal to the miners. This was in October and
+November, 1815, and Stephenson's work antedates that of the great
+philosopher.[52] The controversy which arose between the supporters of
+the rival claims of the two inventors was very earnest, and sometimes
+bitter. The friends of the young engineer raised a subscription,
+amounting to above £1,000, and presented it to him as a token of their
+appreciation of the value of his simple yet important contrivance. Of
+the two forms of lamp, that of Stephenson is claimed to be safest, the
+Davy lamp being liable to produce explosions by igniting the explosive
+gas when, by its combustion within the gauze cylinder, the latter is
+made red-hot. Under similar conditions, the Stephenson lamp is simply
+extinguished, as was seen at Barnsley, in 1857, at the Oaks Colliery,
+where both kinds of lamp were in use, and elsewhere.
+
+  [52] _Vide_ "A Description of the Safety-Lamp invented by George
+  Stephenson," etc., London, 1817.
+
+Stephenson continued to study and experiment, with a view to the
+improvement of his locomotive and the railroad. He introduced better
+methods of track-laying and of jointing the rails, adopting a
+half-lap, or peculiar scarf-joint, in place of the then usual
+square-butt joint. He patented, with these modifications of the
+permanent way, several of his improvements of the engine. He had
+substituted forged for the rude cast wheels previously used,[53] and
+had made many minor changes of detail. The engines built at this time
+(1816) continued in use many years. Two years later, with a
+dynamometer which he designed for the purpose, he made experimental
+determinations of the resistance of trains, and showed that it was
+made up of several kinds, as the sliding friction of the axle-journals
+in their bearings, the rolling friction of the wheels on the rails,
+the resistance due to gravity on gradients, and that due to the
+resistance of the air.
+
+  [53] The American chilled wheel of cast-iron, a better wheel than
+  that above described, has never been generally and successfully
+  introduced in Europe.
+
+These experiments seemed to him conclusive against the possibility of
+the competition of engines on the common highway with locomotives
+hauling trains on the rail. Finding that the resistance, with his
+rolling-stock, and at all the speeds at which he made his experiments,
+was approximately invariable, and equivalent to about 10 pounds per
+ton, and estimating that a gradient rising but 1 foot in 100 would
+decrease the hauling power of the engine 50 per cent., he saw at once
+the necessity of making all railroads as nearly absolutely level as
+possible, and, consequently, the radically distinctive character of
+this branch of civil engineering work. He persistently condemned the
+"folly" of attempting the general introduction of steam on the common
+road, where great changes of level and an impressible road-bed were
+certain to prove fatal to success, and was most strenuous in his
+advocacy of the policy of securing level tracks, even at very great
+expense.
+
+Taking part in the contest, which now became a serious one, between
+the advocates of steam on the common road and those urging the
+introduction of locomotives and their trains on an iron track, he
+calculated that a road-engine capable of carrying 20 or 30 passengers
+at 10 miles per hour, could, on the rail, carry ten times as many
+people at three or four times that speed. The railway-engine finally
+superseded its predecessor--the engine of the common road--almost
+completely.
+
+In 1817, Stephenson built an engine for the Duke of Portland, to haul
+coal from Kilmarnock to Troon, which cost £750, and, with some
+interruptions, this engine worked on that line until 1848, when it was
+broken up. On November 18, 1822, the Hetton Railway, near Sunderland,
+was opened. George Stephenson was the engineer of the line--a short
+track, 8 miles long, built from the Hetton Colliery to the docks on
+the bank of the river Wear. On this line he put in five of the
+"self-acting inclines"--two inclines worked by stationary engines, the
+gradients being too heavy for locomotives--and used five
+locomotive-engines of his own design, which were called by the people
+of the neighborhood, possibly for the first time, "the iron horses."
+These engines were quite similar to the Killingworth engine. They drew
+a train of 17 coal-cars--a total load of 64 tons--about 4 miles an
+hour. Meantime, also, in 1823, Stephenson had been made engineer of
+the Stockton & Darlington Railroad, which had been projected for the
+purpose of securing transportation to tide-water for the valuable
+coal-lands of Durham. This road was built without an expectation on
+the part of any of its promoters, Stephenson excepted, that steam
+would be used as a motor to the exclusion of horses.
+
+Mr. Edward Pearse, however, one of the largest holders of stock in the
+road, and one of its most earnest advocates, became so convinced, by
+an examination of the Killingworth engines and their work, of the
+immense advantage to be derived by their use, that he not only
+supported Stephenson's arguments, but, with Thomas Richardson,
+advanced £1,000 for the purpose of assisting Stephenson to commence
+the business of locomotive-engine construction at Newcastle. This
+workshop, which subsequently became a great and famous establishment,
+was commenced in 1824.
+
+For this road Stephenson recommended wrought-iron rails, which were
+then costing £12 per ton--double the price of cast rails. The
+directors, however, stipulated that he should only buy one-half the
+rails required from the dealers in "malleable" iron. These rails
+weighed 20 pounds to the yard. After long hesitation, in the face of a
+serious opposition, the directors finally concluded to order three
+locomotives of Stephenson. The first, or "No. 1," engine (Fig. 52) was
+delivered in time for the opening of the road, September 27, 1825. It
+weighed 8 tons. Its boiler contained a single straight flue, one end
+of which was the furnace. The cylinders were vertical, like those of
+the earlier engines, and coupled directly to the driving-wheels. The
+crank-pins were set in the wheels at right angles, in order that,
+while one engine was "turning the centre," the other might exert its
+maximum power. The two pairs of drivers were coupled by horizontal
+rods, as seen in the figure, which represents this engine as
+subsequently mounted on a pedestal at the Darlington station. A
+steam-blast in the chimney gave the requisite strength of draught.
+These engines were built for slow and heavy work, but were capable of
+making what was then thought the satisfactorily high speed of 16 miles
+per hour. The inclines on the road were worked by fixed engines.
+
+[Illustration: FIG. 52.--Stephenson's No. 1 Engine, 1825.]
+
+On the opening day, which was celebrated as a holiday by the people
+far and near, the No. 1 engine drew 90 tons at the rate of 12, and at
+times 15, miles an hour.
+
+[Illustration: FIG. 58.--Opening of the Stockton and Darlington
+Railroad, 1815. (After an old engraving.)]
+
+Stephenson's engines were kept at work hauling coal-trains, but the
+passenger-coaches were all drawn for some time by horses, and the
+latter system was a rude forerunner, in most respects, of modern
+street-railway transportation. Mixed passenger and freight trains were
+next introduced, and, soon after, separate passenger-trains drawn by
+faster engines were placed on the line, and the present system of
+railroad transportation was now fairly inaugurated.
+
+A railroad between Manchester and Liverpool had been projected at
+about the time that the Stockton & Darlington road was commenced. The
+preliminary surveys had been made in the face of strong opposition,
+which did not always stop at legal action and verbal attack, but in
+some instances led to the display of force. The surveyors were
+sometimes driven from their work by a mob armed with sticks and
+stones, urged on by land-proprietors and those interested in the lines
+of coaches on the highway. Before the opening of the Stockton &
+Darlington Railroad, the Liverpool & Manchester bill had been carried
+through Parliament, after a very determined effort on the part of
+coach-proprietors and landholders to defeat it, and Stephenson urged
+the adoption of the locomotive to the exclusion of horses. It was his
+assertion, made at this time, that he could build a locomotive to run
+20 miles an hour, that provoked the celebrated rejoinder of a writer
+in the _Quarterly Review_, who was, however, in favor of the
+construction of the road and of the use of the locomotive upon it:
+"What can be more palpably absurd and ridiculous, than the prospect
+held out of locomotives traveling _twice as fast_ as stage-coaches? We
+would as soon expect the people of Woolwich to suffer themselves to be
+fired off upon one of Congreve's ricochet-rockets, as trust themselves
+to the mercy of such a machine going at such a rate."
+
+It was during his examination before a committee of the House of
+Commons, during this contest, that Stephenson, when asked, "Suppose,
+now, one of your engines to be going at the rate of 9 or 10 miles an
+hour, and that a cow were to stray upon the line and get in the way
+of the engine, would not that be a very awkward circumstance?"
+replied, "Yes, _very_ awkward--_for the coo!_" And when asked if men
+and animals would not be frightened by the red-hot smoke-pipe,
+answered, "But how would they know that it was not _painted?_" The
+line was finally built, with George Rennie as consulting, and
+Stephenson as principal constructing engineer.
+
+His work on this road became one of the important elements of the
+success, and one of the great causes of the distinction, which marked
+the life of these rising engineers. The successful construction of
+that part of the line which lay across "Chat Moss," an unfathomable
+swampy deposit of peat, extending over an area of 12 square miles, and
+the building of which had been repeatedly declared an impossibility,
+was in itself sufficient to prove that the engineer who had
+accomplished it was no common man. Stephenson adopted the very simple
+yet bold expedient of using, as a filling, compacted turf and peat,
+and building a road-bed of materials lighter than water, or the
+substance composing the bog, and thus forming a _floating_ embankment,
+on which he laid his rails. To the surprise of every one but
+Stephenson himself, the plan proved perfectly successful, and even
+surprisingly economical, costing but little more than one-tenth the
+estimate of at least one engineer. Among the other great works on this
+remarkable pioneer-line were the tunnel, a mile and a half long, from
+the station at Liverpool to Edgehill; the Olive Mount deep-cut, two
+miles long, and in some places 100 feet deep, through red sandstone,
+of which nearly 500,000 yards were removed; the Sankey Viaduct, a
+brick structure of nine arches, of 50 feet span each, costing £45,000;
+and a number of other pieces of work which are noteworthy in even
+these days of great works.
+
+Stephenson planned all details of the line, and even designed the
+bridges, machinery, engines, turn-tables, switches, and crossings,
+and was responsible for every part of the work of their construction.
+
+Finally, the work of building the line approached completion, and it
+became necessary promptly to settle the long-deferred question of a
+method of applying motive-power. Some of the directors and their
+advisers still advocated the use of horses; many thought stationary
+hauling-engines preferable; and the remainder were, almost to a man,
+undecided. The locomotive had no outspoken advocate, and few had the
+slightest faith in it. George Stephenson was almost alone, and the
+opponents of steam had secured a provision in the Newcastle & Carlisle
+Railroad concession, stipulating expressly that horses should there be
+exclusively employed. The directors did, however, in 1828, permit
+Stephenson to put on the line a locomotive, to be used, during its
+construction, in hauling gravel-trains. A committee was sent, at
+Stephenson's request, to see the Stockton & Darlington engines, but no
+decided expression of opinion seems to have been made by them. Two
+well-known professional engineers reported in favor of fixed engines,
+and advised the division of the line into 19 stages of about a mile
+and a half each, and the use of 21 fixed engines, although they
+admitted the excessive first-cost of that system. The board was
+naturally strongly inclined to adopt their plan. Stephenson, however,
+earnestly and persistently opposed such action, and, after long
+debate, it was finally determined "to give the traveling engine a
+chance." The board decided to offer a reward of £500 for the best
+locomotive-engine, and prescribed the following conditions:
+
+  1. The engine must consume its own smoke.
+
+  2. The engine, if of 6 tons weight, must be able to draw after it,
+  day by day, 20 tons weight (including the tender and water-tank) at
+  10 miles an hour, with a pressure of steam on the boiler not
+  exceeding 50 pounds to the square inch.
+
+  3. The boiler must have two safety-valves, neither of which must be
+  fastened down, and one of them completely out of the control of the
+  engine-man.
+
+  4. The engine and boiler must be supported on springs, and rest on 6
+  wheels, the height of the whole not exceeding 15 feet to the top of
+  the chimney.
+
+  5. The engine, with water, must not weigh more than 6 tons; but an
+  engine of less weight would be preferred, on its drawing a
+  proportionate load behind it; if of only 4-1/2 tons, then it might
+  be put only on 4 wheels. The company to be at liberty to test the
+  boiler, etc., by a pressure of 150 pounds to the square inch.
+
+  6. A mercurial gauge must be affixed to the machine, showing the
+  steam-pressure above 45 pounds to the square inch.
+
+  7. The engine must be delivered, complete and ready for trial, at
+  the Liverpool end of the railway, not later than the 1st of October,
+  1829.
+
+  8. The price of the engine must not exceed £550.
+
+This circular was printed and published throughout the kingdom, and a
+considerable number of engines were constructed to compete at the
+trial, which was proposed to take place October 1, 1829, but which was
+deferred to the 6th of that month. Only four engines, however, were
+finally entered on the day of the trial. These were the "Novelty,"
+constructed by Messrs. Braithwaite & Ericsson, the latter being the
+distinguished engineer who subsequently came to the United States to
+introduce screw-propulsion, and, later, the monitor system of
+iron-clads; the "Rocket," built from Stephenson's plans; and the
+"Sanspareil" and the "Perseverance," built by Hackworth and Burstall,
+respectively.
+
+The "Sanspareil," which was built under the direction of Timothy
+Hackworth, one of Stephenson's earlier foremen, resembled the engine
+built by the latter for the Stockton & Darlington road, but was
+heavier than had been stipulated, was not ready for work when called,
+and, when finally set at work, proved to be very extravagant in its
+use of fuel, partly in consequence of the extreme intensity of its
+blast, which caused the expulsion of unconsumed coals from the
+furnace.
+
+The "Perseverance" could not attain the specified speed, and was
+withdrawn.
+
+[Illustration: FIG. 54.--The "Novelty," 1829.]
+
+The "Novelty" was apparently a well-designed and for that time a
+remarkably well-proportioned machine. _A_, in Fig. 54, is the boiler,
+_D_ the steam-cylinders, _E_ a heater. Its weight but slightly
+exceeded three tons, and it was a "tank engine," carrying its own fuel
+and water at _B_. A forced draught was obtained by means of the
+bellows, _C_. This engine was run over the line at the rate of about
+28 miles an hour at times, but its blowing apparatus failed, and the
+"Rocket" held the track alone. A later trial still left the "Rocket"
+alone in the field.
+
+The "Rocket" (Fig. 55) was built at the works of Robert Stephenson &
+Co., at Newcastle-upon-Tyne. The boiler was given considerable
+heating-surface by the introduction of 25 3-inch copper tubes, at the
+suggestion of Henry Booth, secretary of the railroad company. The
+blast was altered by gradually closing in the opening at the extremity
+of the exhaust-pipe, and thus "sharpening" it until it was found to
+have the requisite intensity. The effect of this modification of the
+shape of the pipe was observed carefully by means of syphon
+water-gauges attached to the chimney. The draft was finally given such
+an intensity as to raise the water 3 inches in the tube of the
+draught-gauge. The total length of the boiler was 6 feet, its
+diameter 40 inches. The fire-box was attached to the rear of the
+boiler, and was 3 feet high and 2 feet wide, with water-legs to
+protect its side-sheets from injury by overheating. The cylinders, as
+seen in the sketch, were inclined, and coupled to a single pair of
+driving-wheels. A tender, attached to the engine, carried the fuel and
+water. The engine weighed less than 4-1/2 tons.
+
+[Illustration: FIG. 55.--The "Rocket," 1829.]
+
+The little engine does not seem to have been very prepossessing in
+appearance, and the "Novelty" is said to have been the general
+favorite, the Stephenson engine having few, if any, backers among the
+spectators. On its first trial, it ran 12 miles in less than an hour.
+
+After the accident which disabled the "Novelty," the "Rocket" came
+forward again, and ran at the rate of from 25 to 30 miles an hour,
+drawing a single carriage carrying 30 passengers. Two days later, on
+the 8th of October, steam was raised in a little less than an hour
+from cold water, and it then, with 13 tons of freight in the train,
+ran 35 miles in 1 hour and 48 minutes, including stops, and attained a
+speed of 29 miles an hour. The average of all runs for the trial was
+15 miles an hour.
+
+This success, far exceeding the expectation of the most sanguine of
+the advocates of the system, and greatly exceeding what had been
+asserted by opponents to be the bounds of possibility, settled
+completely the whole question, and the Manchester & Liverpool road was
+at once equipped with locomotive engines.
+
+The "Rocket" remained on the line until 1837, when it was sold, and
+set at work by the purchasers on the Midgeholme Railway, near
+Carlisle. On one occasion, on this road, it was driven 4 miles in
+4-1/2 minutes. It is now in the Patent Museum at South Kensington,
+London.
+
+In January, 1830, a single line of rails had been carried across Chat
+Moss, and, six months later, the first train, drawn by the "Arrow,"
+ran through, June 14th, from Liverpool to Manchester, making the trip
+in an hour and a half, and attaining a maximum speed of over 27 miles
+an hour. The line was formally opened to traffic September 15, 1830.
+
+This was one of the most notable occasions in the history of the
+railroad, and the successful termination of the great work was
+celebrated, as so important an event should be, by impressive
+ceremonies. Among the distinguished spectators were Sir Robert Peel
+and the Duke of Wellington. Mr. Huskisson, a Member of Parliament for
+Liverpool, was also present. There had been built for the line, by
+Robert Stephenson & Co., 7 locomotives besides the "Rocket," and a
+large number of carriages. These were all brought out in procession,
+and 600 passengers entered the train, which started for Manchester,
+and ran at times, on smooth portions of the road, at the rate of 20
+and 25 miles an hour. Crowds of people along the line cheered at this
+strange and to them incomprehensible spectacle, and the story of the
+wonderful performances of that day on the new railroad was repeated in
+every corner of the land. A sad accident, the precursor of thousands
+to follow the introduction of the new method of transportation, while
+it repressed the rising enthusiasm of the people and dampened the
+ardor of the most earnest of the advocates of the railroad, occurring
+during this trip, assisted in making known the power of the new motor
+and the danger attending its use as well. The trains stopped for water
+at Parkside, and occasion was taken to send the "Northumbrian," an
+engine driven by George Stephenson himself, on a side track, with the
+carriage containing the Duke of Wellington, and the other engines and
+trains were all directed to be sent along the main track in view of
+the Duke and his party. While this movement was in process of
+execution, Mr. Huskisson, who had carelessly stood on the main line
+until the "Rocket," which led the column, had nearly reached him,
+attempted to enter the carriage of the Duke. He was too late, and was
+struck by the "Rocket," thrown down across the rail, and the advancing
+engine crushed a leg so seriously that he died the same evening.
+Immediately after the accident, he was placed on the "Northumbrian,"
+and Stephenson made the 15 miles to the destination of the wounded man
+in 25 minutes--a speed of 36 miles an hour. The news of this accident,
+and the statement of the velocity of the engine, were published
+throughout the kingdom and Europe; and the misfortune of this first
+victim of a railroad accident was one of the causes of the immediate
+adoption and rapid spread of the modern railway system.
+
+This road, which was built in the hope of securing 400 passengers per
+day, almost immediately averaged 1,200, and in five years reported
+500,000 passengers for the year.[54] The success of this road insured
+the general introduction of railroads, and from this time forward
+there was never a doubt of their ultimate adoption to the exclusion
+of every other system of general internal communication and
+transportation.
+
+  [54] Smiles.
+
+For some years after this his first great triumph, George Stephenson
+gave his whole time to the building of railroads and the improvement
+of the engine. He was assisted by his son Robert, to whom he gradually
+surrendered his business, and retired to Tapton House, on the Midland
+Railway, and led a busy but pleasant life during the remaining years
+of his existence.
+
+Even as early as 1840, he seems to have projected many improvements
+which were only generally adopted many years later. He proposed
+self-acting and continuous systems of brake, and considered a good
+system of brake of so great importance, that he advocated their
+compulsory introduction by State legislation. He advised moderate
+speeds, from considerations both of safety and of expense.
+
+A few years after the opening of the Liverpool & Manchester road,
+great numbers of schemes were proposed by ignorant or designing men,
+which had for their object the filling of the pockets of their
+proposers rather than the benefit of the stockholders and the public;
+and the Stephensons were often called upon to combat these crude and
+ill-digested plans. Among these was the pneumatic system of
+propulsion, already referred to as first proposed by Papin, in
+combination with his double-acting air-pump, in 1687. It had been
+again proposed in the early part of the present century by Medhurst,
+who proposed a method of pneumatic transmission of small parcels and
+of letters, which is now in use, and, 15 years later, a railroad to
+take the place of that of Stephenson and his coadjutors. The most
+successful of several attempts to introduce this method was that of
+Clegg & Samuda, at West London, and on the London & Croydon road, and
+again in Ireland, between Kingstown and Dalkey. A line of pipe, _B B_,
+seen in Fig. 56, two feet in diameter, was laid between the rails, _A
+A_, of the road. This pipe was fitted with a nicely-packed piston,
+carrying a strong arm, which rose through a slit made along the top of
+the pipe, and covered by a flexible strip of leather, _E E_. This arm
+was attached to the carriage, _C C_, to be propelled. The pressure of
+the atmosphere being removed, by the action of a powerful pump, from
+the side toward which the train was to advance, the pressure of the
+atmosphere on the opposite side drove the piston forward, carrying the
+train with it. Stephenson was convinced, after examining the plans of
+the projectors, that the scheme would fail, and so expressed himself.
+Those who favored it, however, had sufficient influence with
+capitalists to secure repeated trials, although each was followed by
+failure, and it was several years before the last was heard of this
+system.
+
+[Illustration: FIG. 56.--The Atmospheric Railroad.]
+
+A considerable portion of several of the later years of Stephenson's
+life was spent in traveling in Europe, partly on business and partly
+for pleasure. During a visit to Belgium in 1845, he was received
+everywhere, and by all classes, from the king down to the humblest of
+his subjects, with such distinction as is rarely accorded even to the
+greatest men. He soon after visited Spain with Sir Joshua Walmsley, to
+report on a proposed railway from the capital to the Bay of Biscay. On
+this journey he was taken ill, and his health was permanently
+impaired. Thenceforward he devoted himself principally to the
+direction of his own property, which had become very considerable, and
+spent much of his time at the collieries and other works in which he
+had invested it. His son had now entirely relieved him of all business
+connected with railroads, and he had leisure to devote to
+self-improvement and social amusement. Among his friends he claimed
+Sir Robert Peel, his old acquaintance, now Sir William, Fairbairn, Dr.
+Buckland, and many others of the distinguished men of that time.
+
+In August, 1848, Stephenson was attacked with intermittent fever,
+succeeded by hæmorrhage from the lungs, and died on the 12th of that
+month, at the age of sixty-six years, honored of all men, and secure
+of an undying fame. Soon after his death, statues were erected at
+Liverpool, London, and Newcastle, the cost of the second of which was
+defrayed by private subscriptions, including a contribution of about
+$1,500 by 3,150 workingmen--one of the finest tributes ever offered to
+the memory of a great man.
+
+But the noblest monument is that which he himself erected by the
+establishment of a system of education and protection of his
+working-people at Clay Cross. He made it a condition of employment
+that every employé should contribute from five to twelve pence each
+fortnight to a fund, to which the works also made liberal
+contributions. From that fund it was directed that the expenses of
+free education of the children of the work-people, night-schools for
+those employed in the works, a reading-room and library, medical
+treatment, and a benevolent fund were to be defrayed. Music and
+cricket-clubs, and prize funds for the best garden, were also founded.
+The school, public hall, and the church of Clay Cross, and this noble
+system of support, are together a nobler monument than any statue or
+similar structure could be.
+
+The character of George Stephenson was in every way admirable. Simple,
+earnest, and honorable; courageous, indomitable, and industrious;
+humorous, kind, and philanthropic, his memory will long be cherished,
+and will long prove an incentive to earnest effort and to the pursuit
+of an honorable fame with hundreds of the youth who, reading his
+simple yet absorbing story, as told by his biographer, shall in later
+years learn to know him.
+
+[Illustration: FIG. 57.--Stephenson's Locomotive, 1833.]
+
+After the death of his father, Robert Stephenson continued, as he had
+already done for several years, to conduct the business of building
+locomotives, as well as of constructing railroads. The work of
+locomotive engine-building was done at Newcastle, and for many years
+those works were the principal engine-building establishment of the
+world.
+
+After their introduction on the Liverpool & Manchester road, the
+engines of the firm of Robert Stephenson & Co. were rapidly modified,
+until they assumed the form shown in Fig. 57, which remained standard
+until their gradual increase in weight compelled the builders to place
+a larger number of wheels beneath them, and make those other changes
+which finally resulted in the creation of distinct types for special
+kinds of work. In the engine of 1833, as shown above, the cylinders,
+_A_, are carried at the extreme forward end of the boiler, and the
+driving-wheels, _B_, are coupled directly to the connecting-rod of the
+engine and to each other. A buffer, _C_, extends in front, and the
+rear end of the boiler is formed into a rectangular fire-box, _D_,
+continuous with the shell, _E_, and the flame and gases pass to the
+connection and smoke-pipe, _F_, _G_, through a large number of small
+tubes, _a_. Steam is led to the cylinders by a steam-pipe, _H H_, to
+which it is admitted by the throttle-valve, _b_. A steam-dome, _I_,
+from which the steam is taken, assists by giving more steam-space far
+above the water-line, and thus furnishing dry steam. The exhaust steam
+issues with great velocity into the chimney from the pipe, _J_, giving
+great intensity of draught. The engine-driver stands on the platform,
+_K_, from which all the valves and handles are accessible. Feed-pumps,
+_L_, supply the boiler with water, which is drawn from the tender
+through the pipes, _e_, _f_.
+
+The valve-gear was then substantially what it is to-day, the
+"Stephenson link" (Fig. 58). On the driving-axle were keyed two
+eccentrics, _E_, so set that the motion of the one was adapted to
+driving the valve when the engine was moving forward, and the other
+was arranged to move the valve when running backward. The former was
+connected, through its strap and the rod, _B_, to the upper end of a
+"strap-link," _A_, while the second was similarly connected with the
+lower end. By means of a handle, _L_, and the link, _n_, and its
+connections, including the counterweighted bell-crank, _M_, this link
+could be raised or depressed, thus bringing the pin on the link-block,
+to which the valve-stem was connected, into action with either
+eccentric. Or, the link being set in mid-gear, the valve would cover
+both steam-ports of the cylinder, and the engine could move neither
+way. As shown, the engine is in position to run backward. A series of
+notches, _Z_, into either of which a catch on _L_ could be dropped,
+enabled the driver to place the link where he chose. In intermediate
+positions, between mid-gear and full-gear, the motion of the valve is
+such as to produce expansion of the steam, and some gain in economy of
+working, although reducing the power of the engine.
+
+[Illustration: FIG. 58.--The Stephenson Valve-Gear, 1833.]
+
+The success of the railroad and the locomotive in Great Britain led to
+its rapid introduction in other countries. In France, as early as
+1823, M. Beaunier was authorized to construct a line of rails from the
+coal-mines of St. Étienne to the Loire, using horses for the traction
+of his trains; and in 1826, MM. Seguin began a road from St. Étienne
+to Lyons. In 1832, engines built at Lyons were substituted for horses
+on these roads, but internal agitations interrupted the progress of
+the new system in France, and, for 10 years after the opening
+of the Manchester & Liverpool road, France remained without
+steam-transportation on land.
+
+In Belgium the introduction of the locomotive was more promptly
+accomplished. Under the direction of Pierre Simon, an enterprising and
+well-informed young engineer, who had become known principally as an
+advocate of the even then familiar project of a canal across the
+Isthmus of Darien, very complete plans of railroad communication for
+the kingdom were prepared, in compliance with a decree dated July 31,
+1834, and were promptly authorized. The road between Brussels and
+Mechlin was opened May 6, 1837, and other roads were soon built; and
+the railway system of Belgium was the first on the Continent of
+Europe.
+
+The first German railroad worked with locomotive steam-engines was
+that between Nuremberg and Fürth, built under the direction of M.
+Denis. The other European countries soon followed in this rapid march
+of improvement.
+
+In the United States, public attention had been directed to this
+subject, as has already been stated, very early in the present
+century, by Evans and Stevens. At that time the people of the United
+States, as was natural, closely watched every important series of
+events in the mother-country; and so remarkable and striking a change
+as that which was taking place in the time of Stephenson, in methods
+of communication and transportation, could not fail to attract general
+attention and awaken universal interest.
+
+Notwithstanding the success of the early experiments of Evans and
+others, and in spite of the statesmanlike arguments of Stevens and
+Dearborn, and the earnest advocacy of the plan by all who were
+familiar with the revelations which were daily made of the power and
+capabilities of the steam-engine, it was not until after the opening
+of the Manchester & Liverpool road that any action was taken looking
+to the introduction of the locomotive. Colonel John Stevens, in 1825,
+had built a small locomotive, which he had placed on a circular
+railway before his house--now Hudson Terrace--at Hoboken, to prove
+that his statements had a basis of fact. This engine had two "lantern"
+tubular boilers, each composed of small iron tubes, arranged
+vertically in circles about the furnaces.[55] This exhibition had no
+other effect, however, than to create some interest in the subject,
+which aided in securing a rapid adoption of the railroad when once
+introduced.
+
+  [55] One of these sectional boilers is still preserved in the
+  lecture-room of the author, at the Stevens Institute of Technology.
+
+The first line of rails in the New England States is said to have been
+laid down at Quincy, Mass., from the granite quarry to the Neponset
+River, three miles away, in 1826 and 1827. That between the coal-mines
+of Mauch Chunk, Pa., and the river Lehigh, nine miles distant, was
+built in 1827. In the following year the Delaware & Hudson Canal
+Company built a railroad from their mines to the termination of the
+canal at Honesdale. These roads were worked either by gravity or by
+horses and mules.
+
+The competition at Rainhill, on the Liverpool and Manchester Railroad,
+had been so widely advertised, and promised to afford such conclusive
+evidence relative to the value of the locomotive steam-engine and the
+railroad, that engineers and others interested in the subject came
+from all parts of the world to witness the trial. Among the strangers
+present were Mr. Horatio Allen, then chief-engineer of the Delaware &
+Hudson Canal Company, and Mr. E. L. Miller, a resident of Charleston,
+S. C., who went from the United States for the express purpose of
+seeing the new machines tested.
+
+Mr. Allen had been authorized to purchase, for the company with which
+he was connected, three locomotives and the iron for the road, and had
+already shipped one engine to the United States, and had set it at
+work on the road. This engine was received in New York in May, 1829,
+and its trial took place in August at Honesdale, Mr. Allen himself
+driving the engine. But the track proved too light for the locomotive,
+and it was laid up and never set at regular work. This engine was
+called the "Stourbridge Lion"; it was built by Foster, Rastrick & Co.,
+of Stourbridge, England. During the summer of the next year, a small
+experimental engine, which was built in 1829 by Peter Cooper, of New
+York, was successfully tried on the Baltimore & Ohio Railroad, at
+Baltimore, making 13 miles in less than an hour, and moving, at some
+points on the road, at the rate of 18 miles an hour. One carriage
+carrying 36 passengers was attached. This was considered a
+working-model only, and was rated at one horse-power.
+
+Ross Winans, writing of this trial of Cooper's engine, makes a
+comparison with the work done by Stephenson's "Rocket," and claims a
+decided superiority for the former. He concluded that the trial
+established fully the practicability of using locomotives on the
+Baltimore & Ohio road at high speeds, and on all its curves and heavy
+gradients, without inconvenience or danger.
+
+This engine had a vertical tubular boiler, and the draught was urged,
+like that of the "Novelty" at Liverpool, by mechanical means--a
+revolving fan. The single steam-cylinder was 3-1/4 inches in diameter,
+and the stroke of piston 14-1/2 inches. The wheels were 30 inches in
+diameter, and connected to the crank-shaft by gearing. The engine, on
+the trial, worked up to 1.43 horse-power, and drew a gross weight of
+4-1/2 tons. Mr. Cooper, unable to find such tubes as he needed for his
+boiler, used gun-barrels. The whole machine weighed less than a ton.
+
+Messrs. Davis & Gartner, a little later, built the "York" for this
+road--a locomotive having also a vertical boiler, of very similar form
+to the modern steam fire-engine boiler, 51 inches in diameter, and
+containing 282 fire-tubes, 16 inches long, and tapering from 1-1/2
+inches diameter at the bottom to 1-1/4 at the top, where the gases
+were discharged through a combustion-chamber into a steam-chimney.
+This engine weighed 3-1/2 tons.
+
+They subsequently built several "grasshopper" engines (Fig. 59), some
+of which ran many years, doing good work, and one or two of which are
+still in existence. The first--the "Atlantic"--was set at work in
+September, 1832, and hauled 50 tons from Baltimore 40 miles, over
+gradients having a maximum rise of 37 feet to the mile, and on curves
+having a minimum radius of 400 feet, at the rate of 12 to 15 miles an
+hour. This engine weighed 6-1/2 tons, carried 50 pounds of steam--a
+pressure then common on both continents --and burned a ton of
+anthracite coal on the round trip. The blast was secured by a fan, and
+the valve-gear was worked by cams instead of eccentrics. This engine
+made the round trip at a cost of $16, doing the work of 42 horses,
+which had cost $33 per trip. The engine cost $4,500, and was designed
+by Phineas Davis, assisted by Ross Winans.
+
+[Illustration: FIG. 59.--The "Atlantic," 1882.]
+
+Mr. Miller, on his return from the Liverpool & Manchester trial,
+ordered a locomotive for the Charleston & Hamburg Railroad from the
+West Point Foundery. This engine was guaranteed by Mr. Miller to draw
+three times its weight at the rate of 10 miles an hour. It was built
+during the summer of 1830, from the plans of Mr. Miller, and reached
+Charleston in October. The trials were made in November and December.
+
+[Illustration: FIG. 60.--The "Best Friend," 1830.]
+
+This engine (Fig. 60) had a vertical tubular boiler, in which the
+gases rose through a very high fire-box, into which large numbers of
+rods projected from the sides and top, and passed out through tubes
+leading them laterally outward into an outside jacket, through which
+they rose to the chimney. The steam-cylinders were two in number, 8
+inches in diameter and of 16 inches stroke, inclined so as to connect
+with the driving-axle. The four wheels were all of the same size,
+4-1/2 feet in diameter, and connected by coupling-rods. The engine
+weighed 4-1/2 tons. The "Best Friend," as it was called, did excellent
+work until June, 1831, when the explosion of the boiler, in
+consequence of the recklessness of the fireman, unexpectedly closed
+its career.
+
+A second engine (Fig. 61) was built for this road, at the West Point
+Foundery, from plans furnished by Horatio Allen, and was received and
+set at work early in the spring of 1831. The engine, called the "West
+Point," had a horizontal tubular boiler, but was in other respects
+very similar to the "Best Friend." It is said to have done very good
+work.
+
+[Illustration: FIG. 61.--The "West Point," 1831.]
+
+The Mohawk & Hudson Railroad ordered an engine at about this time,
+also, of the West Point Foundery, and the trials, made in July and
+August, 1831, proved thoroughly successful.
+
+This engine, the "De Witt Clinton," was contracted for by John B.
+Jervis, and fitted up by David Matthew. It had two steam-cylinders,
+each 5-1/2 inches in diameter and 16 inches stroke of piston. The
+connecting-rods were directly attached to a cranked axle, and turned
+four coupled wheels 4-1/2 feet in diameter. These wheels had cast-iron
+hubs and wrought-iron spokes and tires. The tubes were of copper,
+2-1/2 inches in diameter and 6 feet long. The engine weighed 3-1/2
+tons, and hauled 5 cars at the rate of 30 miles an hour.
+
+Another engine, the "South Carolina" (Fig. 62), was designed by
+Horatio Allen for the South Carolina Railroad, and completed late in
+the year 1831. This was the first eight-wheeled engine, and the
+prototype, also, of a peculiar and lately-revived form of engine.
+
+In the summer of 1832, an engine built by Messrs. Davis & Gartner, of
+York, Pa., was put on the Baltimore & Ohio road, which at times
+attained a speed, unloaded, of 30 miles an hour. The engine weighed
+3-1/2 tons, and drew, usually, 4 cars, weighing altogether 14 tons,
+from Baltimore to Ellicott's Mills, a distance of 13 miles, in the
+schedule-time, one hour.
+
+[Illustration: FIG. 62.--The "South Carolina," 1831.]
+
+Horatio Allen's engine on the South Carolina Railroad is said to have
+been the first eight-wheeled engine ever built.
+
+It was at about the time of which we are now writing that the first
+locomotive was built of what is now distinctively known as the
+American type--an engine with a "truck" or "bogie" under the forward
+end of the boiler. This was the "American" No. 1, built at the West
+Point Foundery, from plans furnished by John B. Jervis, Chief
+Engineer, for the Mohawk & Hudson Railroad. Ross Winans had already
+(1831) introduced the passenger-car with swiveling trucks.[56] It was
+completed in August, 1832, and is said by Mr. Matthew to have been an
+extremely fast and smooth-running engine. A mile a minute was
+repeatedly attained, and it is stated by the same authority,[57] that
+a speed of 80 miles an hour was sometimes made over a single mile.
+This engine had cylinders 9-1/2 inches diameter, 16 inches stroke of
+piston, two pairs of driving-wheels, coupled, 5 feet in diameter each;
+and the truck had four 33-inch wheels. The boiler contained tubes 3
+inches in diameter, and its fire-box was 5 feet long and 2 feet 10
+inches wide. Robert Stephenson & Co. subsequently built a similar
+engine, from the plans of Mr. Jervis, and for the same road. It was
+set at work in 1833. In both engines the driving-wheels were behind
+the fire-box. This engine is another illustration of the fact--shown
+by the description already given of other and earlier engines--that
+the independence of the American mechanic, and the boldness and
+self-confidence which have to the present time distinguished him, were
+among the earliest of the fruits of our political independence and
+freedom.
+
+  [56] "History of the First Locomotives in America," Brown.
+
+  [57] "Ross Winans _vs._ The Eastern Railroad Company--Evidence."
+  Boston, 1854.
+
+These American engines were all designed to burn anthracite coal. The
+English locomotives all burned bituminous coal.
+
+Robert L. Stevens, the President and Engineer of the Camden & Amboy
+Railroad, and a distinguished son of Colonel John Stevens, of Hoboken,
+was engaged, at the time of the opening of the Liverpool & Manchester
+Railroad, in the construction of the Camden & Amboy Railroad. It was
+here that the first of the now standard form of _T_-rail was laid
+down. It was of malleable iron, and of the form shown in the
+accompanying figure. It was designed by Mr. Stevens, and is known in
+the United States as the "Stevens" rail. In Europe, where it was
+introduced some years afterward, it is sometimes called the
+"Vignolles" rail. He purchased an engine of the Stephensons soon after
+the trial at Rainhill, and this engine, the "John Bull," was set up on
+the then uncompleted road at Bordentown, in the year 1831. Its first
+public trial was made in November of that year. The road was opened
+for traffic, from end to end, two years later. This engine had
+steam-cylinders 9 inches in diameter, 2 feet stroke of piston, one
+pair of drivers 4-1/2 feet in diameter, and weighed 10 tons. This
+engine, and that built by Phineas Davis for the Baltimore & Ohio
+Railroad, were exhibited at the Centennial Exhibition at Philadelphia,
+in the year 1876.
+
+[Illustration: FIG. 63.--The "Stevens" Rail. Enlarged Section.]
+
+[Illustration: FIG. 64.--"Old Ironsides," 1832.]
+
+Engines supplied to the Camden & Amboy Railroad subsequent to 1831
+were built from the designs of Robert L. Stevens, in the shop of the
+Messrs. Stevens, at Hoboken. The other principal roads of the country,
+at first, very generally purchased their engines of the Baldwin
+Locomotive Works, then a small shop owned by Matthias W. Baldwin.
+Baldwin's first engine was a little model built for Peale's Museum, to
+illustrate to the visitors of that then well-known place of
+entertainment the character of the new motor, the success of which,
+at Rainhill, had just then excited the attention of the world. This
+was in 1831, and the successful working of this little model led to
+his receiving an order for an engine from the Philadelphia &
+Germantown Railroad. Mr. Baldwin, after studying the new engine of the
+Camden & Amboy road, made his plans, and built an engine (Fig. 64),
+completing it in the autumn of 1832, and setting it in operation
+November 23d of that year. It was kept at work on that line of road
+for a period of 20 years or more. This engine was of Stephenson's
+"Planet" class, mounted on two driving-wheels 4-1/2 feet in diameter
+each, and two separate wheels of the same size, uncoupled. The
+steam-cylinders were 9-1/2 inches in diameter, 18 inches stroke of
+piston, and were placed horizontally on each side of the smoke-box.
+The boiler, 2-1/2 feet in diameter, contained 72 copper tubes 1-1/2
+inches in diameter and 7 feet long. The engine cost the railroad
+company $3,500. On the trial, steam was raised in 20 minutes, and the
+maximum speed noted was 28 miles an hour. The engine subsequently
+attained a speed of over 30 miles. In 1834, Mr. Baldwin completed for
+Mr. E. L. Miller, of Charleston, a six-wheeled engine, the "E. L.
+Miller" (Fig. 65), with cylinders 10 inches in diameter and 16 inches
+stroke of piston. He made the boiler of this engine of a form which
+remained standard many years, with a high dome over the fire-box. At
+about the same time, he built the "Lancaster," an engine resembling
+the "Miller," for the State road to Columbia, and several others were
+soon contracted for and built. By the end of 1834, 5 engines had been
+built by him, and the construction of locomotive-engines had become
+one of the leading and most promising industries of the United States.
+Mr. William Norris established a shop in Philadelphia in 1832, which
+he gradually enlarged until it, like the Baldwin Works, became a large
+establishment. He usually built a six-wheeled engine, with a
+leading-truck or bogie, and placed his driving-wheels in front of the
+fire-box.
+
+[Illustration: FIG. 65.--The "E. L. Miller," 1834.]
+
+At this time the English locomotives were built to carry 60 pounds of
+steam. The American builders adopted pressures of 120 to 130 pounds
+per square inch, the now generally standard pressures throughout the
+world. In the years 1836 and 1837, Baldwin built 80 engines. They were
+of three classes: 1st, with cylinders 12-1/2 inches in diameter and of
+16 inches stroke, weighing 12 tons; 2d, with cylinders 12 by 16, and
+a weight of 10-1/2 tons; and 3d, engines weighing 9 tons, and having
+steam-cylinders of 10-1/2 inches diameter and of the same stroke. The
+driving-wheels were usually 4-1/2 feet in diameter, and the cylinder
+"inside-connected" to cranked axles. A few "outside-connected" engines
+were made, this plan becoming generally adopted at a later period.
+
+The railroads of the United States were very soon supplied with
+locomotive-engines built in America. In the year 1836, William Norris,
+who had two years before purchased the interest of Colonel Stephen H.
+Long, an army-officer who patented and built locomotives of his own
+design, built the "George Washington," and set it at work. This
+engine, weighing 14,400 pounds, drew 19,200 pounds up an incline 2,800
+feet long, rising 369 feet to the mile, at the speed of 15-1/2 miles
+an hour. This showed an adhesion not far from one-third the weight on
+the driving-wheels. This was considered a very wonderful performance,
+and it produced such an impression at the time, that several copies of
+the "George Washington" were made, on orders from British railroads,
+and the result was the establishment of the reputation of the
+locomotive-engine builders of the United States upon a foundation
+which has never since failed them. The engine had Jervis's
+forward-truck, now always seen under standard engines, which had
+already been placed under railroad-cars by Ross Winans.
+
+In New England, the Locks & Canals Company, of Lowell, began building
+engines as early as 1834, copying the Stephenson engine. Hinckley &
+Drury, of Boston, commenced building an outside-connected engine in
+1840, and their successors, the Boston Locomotive Works, became the
+largest manufacturing establishment of the kind in New England. Two
+years later, Ross Winans, the Baltimore builder, introduced some of
+his engines upon Eastern railroads, fitting them with upright boilers,
+and burning anthracite coal.
+
+The changes which have been outlined produced the now typical American
+locomotive. It was necessarily given such form that it would work
+safely and efficiently on rough, ill-ballasted, and often
+sharply-winding tracks; and thus it soon became evident that the two
+pairs of coupled driving-wheels, carrying two-thirds the weight of the
+whole engine, the forward-truck, and the system of "equalizing"
+suspension-bars, by which the weight is distributed fairly among all
+the wheels, whatever the position of the engine, or whatever the
+irregularity of the track, made it the very best of all known types of
+locomotive for the railroads of a new country. Experience has shown it
+equally excellent on the smoothest and best of roads. The
+"cow-catcher," placed in front to remove obstacles from the track, the
+bell, and the heavy whistle, are characteristics of the American
+engine also. The severity of winter-storms compelled the adoption of
+the "cab," or house, and the use of wood for fuel led to the invention
+of the "spark-arrester" for that class of engines. The heavy grades on
+many roads led to the use of the "sand-box," from which sand was
+sprinkled on the track, to prevent the slipping of the wheels.
+
+In the year 1836, the now standard chilled wheel was introduced for
+cars and trucks; the single eccentric, which had been, until then,
+used on Baldwin engines, was displaced by the double eccentric, with
+hooks in place of the link; and, a year later, the iron frame took the
+place of the previously-used wooden frame on all engines.
+
+The year 1837 introduced a period of great depression in all branches
+of industry, which continued until the year 1840, or later, and
+seriously checked all kinds of manufacturing, including the building
+of locomotives. On the revival of business, numbers of new
+locomotive-works were started, and in these establishments originated
+many new types of engine, each of the more successful of which was
+adapted to some peculiar set of conditions. This variety of type is
+still seen on nearly all of the principal roads.
+
+The direction of change in the construction of locomotive-engines at
+the period at which this division of the subject terminates is very
+well indicated in a letter from Robert Stephenson to Robert L.
+Stevens, dated 1833, which is now preserved at the Stevens Institute
+of Technology. He writes: "I am sorry that the feeling in the United
+States in favor of light railways is so general. In England we are
+making every succeeding railway stronger and more substantial." He
+adds: "Small engines are losing ground, and large ones are daily
+demonstrating that powerful engines are the most economical." He gives
+a sketch of his latest engine, weighing _nine tons_, and capable, as
+he states, of "taking 100 tons, gross load, at the rate of 16 or 17
+miles an hour on a level." To-day there are engines built weighing 70
+tons, and our locomotive-builders have standard sizes guaranteed to
+draw over 2,000 tons on a good and level track.
+
+[Illustration]
+
+
+
+
+CHAPTER V.
+
+_THE MODERN STEAM-ENGINE._
+
+  "Voilà la plus merveilleuse de toutes les Machines; le Mécanisme
+  ressemble à celui des animaux. La chaleur est le principe de son
+  mouvement; il se fait dans ses différens tuyaux une circulation,
+  comme celle du sang dans les veines, ayant des valvules qui
+  s'ouvrent et se ferment à propos; elles se nourrit, s'évacue d'elle
+  même dans les temps réglés, et tire de son travail tout ce qu'il lui
+  faut pour subsister. Cette Machine a pris sa naissance en
+  Angleterre, et toutes les Machines à feu qu'on a construites
+  ailleurs que dans la Grande Brétagne ont été exécutées par des
+  Anglais."--BELIDOR.
+
+THE SECOND PERIOD OF APPLICATION--1800-1850 (CONTINUED). THE
+STEAM-ENGINE APPLIED TO SHIP-PROPULSION.
+
+
+Among the most obviously important and most inconceivably fruitful of
+all the applications of steam which marked the period we are now
+studying, is that of the steam-engine to the propulsion of vessels.
+This direction of application has been that which has, from the
+earliest period in the history of the steam-engine, attracted the
+attention of the political economist and the historian, as well as the
+mechanician, whenever a new improvement, or the revival of an old
+device, has awakened a faint conception of the possibilities attendant
+upon the introduction of a machine capable of making so great a force
+available. The realization of the hopes, the prophecies, and the
+aspirations of earlier times, in the modern marine steam-engine, may
+be justly regarded as the greatest of all the triumphs of mechanical
+engineering. Although, as has already been stated, attempts were made
+at a very early period to effect this application of steam-power, they
+were not successful, and the steamship is a product of the present
+century. No such attempts were commercially successful until after the
+time of Newcomen and Watt, and at the commencement of the nineteenth
+century. It is, indeed, but a few years since the passage across the
+Atlantic was frequently made in sailing-vessels, and the dangers, the
+discomforts, and the irregularities of their trips were most serious.
+Now, hardly a day passes that does not see several large and powerful
+steamers leaving the ports of New York and Liverpool to make the same
+voyages, and their passages are made with such regularity and safety,
+that travelers can anticipate with confidence the time of their
+arrival at the termination of their voyage to a day, and can cross
+with safety and with comparative comfort even amid the storms of
+winter. Yet all that we to-day see of the extent and the efficiency of
+steam-navigation has been the work of the present century, and it may
+well excite our wonder and our admiration.
+
+The history of this development of the use of steam-power illustrates
+most perfectly that process of growth of this invention which has been
+already referred to; and we can here trace it, step by step, from the
+earliest and rudest devices up to those most recent and most perfect
+designs which represent the most successful existing types of the
+heat-engine--whether considered with reference to its design and
+construction, or as the highest application of known scientific
+principles--that have yet been seen in even the present advanced state
+of the mechanic arts.
+
+The paddle-wheel was used as a substitute for oars at a very early
+date, and a description of paddle-wheels applied to vessels, curiously
+illustrated by a large wood-cut, may be found in the work of Fammelli,
+"De l'artificioses machines," published in old French in 1588.
+Clark[58] quotes from Ogilby's edition of the "Odyssey" a stanza
+which reads like a prophecy, and almost awakens a belief that the
+great poet had a knowledge of steam-vessels in those early times--a
+thousand years before the Christian era. The prince thus addresses
+Ulysses:
+
+  [58] "Steam and the Steam-Engine."
+
+    "We use nor Helm nor Helms-man. Our tall ships
+    Have Souls, and plow with Reason up the deeps;
+    All cities, Countries know, and where they list,
+    Through billows glide, veiled in obscuring Mist;
+    Nor fear they Rocks, nor Dangers on the way."
+
+Pope's translation[59] furnishes the following rendering of Homer's
+prophecy:
+
+  [59] "Odyssey," Book VIII., p. 175.
+
+    "So shalt thou instant reach the realm assigned,
+    In wondrous ships, self-moved, instinct with mind;
+
+    ...
+
+    Though clouds and darkness veil the encumbered sky,
+    Fearless, through darkness and through clouds they fly.
+    Though tempests rage, though rolls the swelling main,
+    The seas may roll, the tempests swell in vain;
+    E'en the stern god that o'er the waves presides,
+    Safe as they pass and safe repass the tide,
+    With fury burns; while, careless, they convey
+    Promiscuous every guest to every bay."
+
+It is stated that the Roman army under Claudius Caudex was taken
+across to Sicily in boats propelled by paddle-wheels turned by oxen.
+Vulturius gives pictures of such vessels.
+
+This application of the force of steam was very possibly anticipated
+600 years ago by Roger Bacon, the learned Franciscan monk, who, in an
+age of ignorance and intellectual torpor, wrote:
+
+"I will now mention some wonderful works of art and nature, in which
+there is nothing of magic, and which magic could not perform.
+Instruments may be made by which the largest ships, with only one man
+guiding them, will be carried with greater velocity than if they were
+full of sailors," etc., etc.
+
+Darwin's poetical prophecy was published long years before Watt's
+engine rendered its partial fulfillment a possibility; and thus, for
+many years before even the first promising effort had been made, the
+minds of the more intelligent had been prepared to appreciate the
+invention when it should finally be brought forward.
+
+The earliest attempt to propel a vessel by steam is claimed by Spanish
+authorities, as has been stated, to have been made by Blasco de Garay,
+in the harbor of Barcelona, Spain, in 1543. The record, claimed as
+having been extracted from the Spanish archives at Simancas, states
+the vessel to have been of 200 tons burden, and to have been moved by
+paddle-wheels; and it is added that the spectators saw, although not
+allowed closely to inspect the apparatus, that one part of it was a
+"vessel of boiling water"; and it is also stated that objection was
+made to the use of this part of the machine, because of the danger of
+explosion.
+
+The account seems somewhat apocryphal, and it certainly led to no
+useful results.
+
+In an anonymous English pamphlet, published in 1651, which is supposed
+by Stuart to have been written by the Marquis of Worcester, an
+indefinite reference to what may probably have been the steam-engine
+is made, and it is there stated to be capable of successful
+application to propelling boats.
+
+In 1690, Papin proposed to use his piston-engine to drive
+paddle-wheels to propel vessels; and in 1707 he applied the
+steam-engine, which he had proposed as a pumping-engine, to driving a
+model boat on the Fulda at Cassel. In this trial he used the
+arrangement of which a sketch has been shown, his pumping-engine
+forcing up water to turn a water-wheel, which, in turn, was made to
+drive the paddles. An account of his experiments is to be found in
+manuscript in the correspondence between Leibnitz and Papin, preserved
+in the Royal Library at Hanover. Professor Joy found there the
+following letter:[60]
+
+  "Dionysius Papin, Councillor and Physician to his Royal Highness the
+  Elector of Cassel, also Professor of Mathematics at Marburg, is
+  about to dispatch a vessel of singular construction down the river
+  Weser to Bremen. As he learns that all ships coming from Cassel, or
+  any point on the Fulda, are not permitted to enter the Weser, but
+  are required to unload at Münden, and as he anticipates some
+  difficulty, although those vessels have a different object, his own
+  not being intended for freight, he begs most humbly that a gracious
+  order be granted that his ship may be allowed to pass unmolested
+  through the Electoral domain; which petition I most humbly support.
+
+                                                        G. W. LEIBNITZ.
+  "HANOVER, _July 13, 1707_."
+
+This letter was returned to Leibnitz, with the following indorsement:
+
+  "The Electoral Councillors have found serious obstacles in the way of
+  granting the above petition, and, without giving their reasons, have
+  directed me to inform you of their decision, and that, in consequence,
+  the request is not granted by his Electoral Highness.
+
+                                                             H. REICHE.
+  "HANOVER, _July 25, 1707_."
+
+  [60] _Scientific American_, February 24, 1877.
+
+This failure of Papin's petition was the death-blow to his effort to
+establish steam-navigation. A mob of boatmen, who thought they saw in
+the embryo steamship the ruin of their business, attacked the vessel
+at night, and utterly destroyed it. Papin narrowly escaped with his
+life, and fled to England.
+
+In the year 1736, Jonathan Hulls took out an English patent for the
+use of a steam-engine for ship-propulsion, proposing to employ his
+steamboat in towing. In 1737 he published a well-written pamphlet,
+describing this apparatus, which is shown in Fig. 66, a reduced
+fac-simile of the plate accompanying his paper.
+
+[Illustration: FIG. 66.--Hulls's Steamboat, 1736.]
+
+He proposed using the Newcomen engine, fitted with a
+counterpoise-weight and a system of ropes and grooved wheels, which,
+by a peculiar ratchet-like action, gave a continuous rotary motion.
+His vessel was to have been used as a tow-boat. He says, in his
+description: "In some convenient part of the Tow-boat there is placed
+a Vessel about two-3rds full of water, with the Top closed; and this
+Vessel being kept Boiling, rarifies the Water into a Steam, this Steam
+being convey'd thro' a large pipe into a cylindrical Vessel, and there
+condensed, makes a Vacuum, which causes the weight of the atmosphere
+to press down on this Vessel, and so presses down a Piston that is
+fitted into this Cylindrical Vessel, in the same manner as in Mr.
+Newcomen's Engine, with which he raises Water by Fire.
+
+"_P_, the Pipe coming from the Furnace to the Cylinder. _Q_, the
+Cylinder wherein the steam is condensed. _R_, the Valve that stops the
+Steam from coming into the Cylinder, whilst the Steam within the same
+is condensed. _S_, the Pipe to convey the condensing Water into the
+Cylinder. _T_, a cock to let in the condensing Water when the Cylinder
+is full of Steam and the Valve, _P_, is shut. _U_, a Rope fixed to the
+Piston that slides up and down in the Cylinder.
+
+"_Note._ This Rope, _U_, is the same Rope that goes round the wheel,
+_D_, in the machine."
+
+In the large division of his plate, _A_ is the chimney; _B_ is the
+tow-boat; _C C_ is the frame carrying the engine; _Da_, _D_, and _Db_
+are three wheels carrying the ropes _M_, _Fb_, and _Fa_, _M_ being the
+rope _U_ of his smaller figure, 30. _Ha_ and _Hb_ are two wheels on
+the paddle-shafts, _I I_, arranged with pawls so that the
+paddle-wheel, _I I_, always turns the same way, though the wheels _Ha_
+and _Hb_ are given a reciprocating motion; _Fb_ is a rope connecting
+the wheels in the vessel, _Db_, with the wheels at the stern. Hulls
+says:
+
+"When the Weight, _G_, is so raised, while the wheels _Da_, _D_, and
+_Db_ are moving backward, the Rope _Fa_ gives way, and the Power of
+the Weight, _G_, brings the Wheel _Ha_ forward, and the Fans with it,
+so that the Fans always keep going forward, notwithstanding the Wheels
+_Da_, _D_, and _Db_ move backward and forward as the Piston moves up
+and down in the Cylinder. _L L_ are Teeth for a Catch to drop in from
+the Axis, and are so contrived that they catch in an alternate manner,
+to cause the Fan to move always forward, for the Wheel _Ha_, by the
+power of the weight, _G_, is performing his Office while the other
+wheel, _Hb_, goes back in order to fetch another stroke.
+
+"_Note._ The weight, _G_, must contain but half the weight of the
+Pillar of Air pressing on the Piston, because the weight, _G_, is
+raised at the same time as the Wheel _Hb_ performs its Office, so that
+it is in effect two Machines acting alternately, by the weight of one
+Pillar of Air, of such a Diameter as the Diameter of the Cylinder is."
+
+The inventor suggests the use of timber guards to protect the wheels
+from injury, and, in shallow water, the attachment to the
+paddle-shafts of cranks "to strike a Shaft to the Bottom of the River,
+which will drive the Vessel forward with the greater Force." He
+concludes: "Thus I have endeavoured to give a clear and satisfactory
+Account of my New-invented Machine, for carrying Vessels out of and
+into any Port, Harbour, or River, against Wind and Tide, or in a Calm;
+and I doubt not but whoever shall give himself the Trouble to peruse
+this Essay, will be so candid as to excuse or overlook any
+Imperfections in the diction or manner of writing, considering the
+Hand it comes from, if what I have imagined may only appear as plain
+to others as it has done to me, viz., That the Scheme I now offer is
+Practicable, and if encouraged will be Useful."
+
+There is no positive evidence that Hulls ever put his scheme to the
+test of experiment, although tradition does say that he made a model,
+which he tried with such ill success as to prevent his prosecution of
+the experiment further; and doggerel rhymes are still extant which
+were sung by his neighbors in derision of his folly, as they
+considered it.
+
+A prize was awarded by the French Academy of Sciences, in 1752, for
+the best essay on the manner of impelling vessels without wind. It was
+given to Bernouilli, who, in his paper, proposed a set of vanes like
+those of a windmill--a screw, in fact--one to be placed on each side
+of the vessel, and two more behind. For a vessel of 100 tons, he
+proposed a shaft 14 feet long and 2 inches in diameter, carrying
+"eight wheels, for acting on the water, to each of which it" (the
+shaft) "is perpendicular, and forms an axis for them all; the wheels
+should be at equal distances from each other. Each wheel consists of 8
+arms of iron, each 3 feet long, so that the whole diameter of the
+wheel is 6 feet. Each of these arms, at the distance of 20 inches from
+the centre, carries a sheet-iron plane (or paddle) 16 inches square,
+which is inclined so as to form an angle of 60 degrees, both with the
+arbor and keel of the vessel, to which the arbor is placed parallel.
+To sustain this arbor and the wheels, two strong bars of iron, between
+2 and 3 inches thick, proceed from the side of the vessel at right
+angles to it, about 2-1/2 feet below the surface of the water." He
+proposed similar screw-propellers at the stern, and suggested that
+they could be driven by animal or by steam-power.
+
+But a more remarkable essay is quoted by Figuier[61]--the paper of
+l'Abbé Gauthier, published in the "Mémoires de la Société Royale des
+Sciences et Lettres de Nancy." Bernouilli had expressed the belief
+that the best steam-engine then known--that of Newcomen--was not
+superior to some other motors. Gauthier proposed to use that engine in
+the propulsion of paddle-wheels placed at the side of the vessel. His
+plan was not brought into use, but his paper embodied a glowing
+description of the advantages to be secured by its adoption. He states
+that a galley urged by 26 oars on a side made but 4,320 toises (8,420
+meters), or about 5 miles, an hour, and required a crew of 260 men. A
+steam-engine, doing the same work, would be ready for action at all
+times, could be applied, when not driving the vessel, to raising the
+anchor, working the pumps, and to ventilating the ship, while the fire
+would also serve to cook with. The engine would occupy less space and
+weight than the men, would require less aliment, and that of a less
+expensive kind, etc. He would make the boiler safe against explosions
+by bands of iron; would make the fire-box of iron, with a water-filled
+ash-pit and base-plate. His injection-water was to come from the sea,
+and return by a delivery-pipe placed above the water-line. The chains,
+usually leading from the end of the beam to the pump-rods, were to be
+carried around wheels on the paddle-shaft, which were to be provided
+with pawls entering a ratchet, and thus the paddles, having been given
+several revolutions by the descent of the piston and the unwinding of
+the chain, were to revolve freely while the return-stroke was made,
+the chain being hauled down and rewound by the wheel on the shaft, the
+latter being moved by a weight. The engine was proposed to be of 6
+feet stroke, and to make 15 strokes per minute, with a force of 11,000
+pounds.
+
+  [61] "Les Merveilles de la Science."
+
+A little later (1760), a Swiss clergyman, J. A. Genevois, published
+in London a paper relating to the improvement of navigation,[62] in
+which his plan was proposed of compressing springs by steam or other
+power, and applying their effort while recovering their form to
+ship-propulsion.
+
+  [62] "Some New Enquiries tending to the Improvement of Navigation."
+  London, 1760.
+
+It was at this time that the first attempts were made in the United
+States to solve this problem, which had begun to be recognized as one
+of the greatest which had presented itself to the mechanic and the
+engineer.
+
+WILLIAM HENRY was a prominent citizen of the then little village of
+Lancaster, Pa., and was noted as an ingenious and successful
+mechanic.[63] He was still living at the beginning of the present
+century. Mr. Henry was the first to make the "rag" carpet, and was the
+inventor of the screw-auger. He was of a Scotch and North-of-Ireland
+family, his father, John Henry, and his two older brothers, Robert and
+James, having come to the United States about 1720. Robert settled,
+finally, in Virginia, and it is said that Patrick Henry, the patriot
+and orator, was of his family. The others remained in Chester County,
+Pa., where William was born, in 1729. He learned the trade of a
+gunsmith, and, driven from his home during the Indian war (1755 to
+1760), settled in Lancaster.
+
+  [63] _Lancaster Daily Express_, December 10, 1872. This account is
+  collated from various manuscripts and letters in the possession of
+  the author.
+
+In the year 1760 he went to England on business, where his attention
+was attracted to the invention--then new, and the subject of
+discussion in every circle--of James Watt. He saw the possibility of
+its application to navigation and to driving carriages, and, on his
+return home, commenced the construction of a steam-engine, and
+finished it in 1763.
+
+Placing it in a boat fitted with paddle-wheels, he made a trial of the
+new machine on the Conestoga River, near Lancaster, where the craft,
+by some accident, sank,[64] and was lost. He was not discouraged by
+this failure, but made a second model, adding some improvements. Among
+the records of the Pennsylvania Philosophical Society is, or was, a
+design, presented by Henry in 1782, of one of his steamboats. The
+German traveler Schöpff visited the United States in 1783, and at Mr.
+Henry's house, at Lancaster, was shown "a machine by Mr. Henry,
+intended for the propelling of boats, etc.; 'but,' said Mr. Henry, 'I
+am doubtful whether such a machine would find favor with the public,
+as every one considers it impracticable against wind and tide;' but
+that such a Boat _will_ come into use and navigate on the waters of
+the Ohio and Mississippi, he had not the least doubt of, but the time
+had not yet arrived of its being appreciated and applied."
+
+  [64] Bowen's "Sketches," p. 56.
+
+John Fitch, whose experiments will presently be referred to, was an
+acquaintance and frequent visitor to the house of Mr. Henry, and may
+probably have there received the earliest suggestions of the
+importance of this application of steam. About 1777, when Henry was
+engaged in making mathematical and philosophical instruments, and the
+screw-auger, which at that time could only be obtained of him, Robert
+Fulton, then twelve years old, visited him, to study the paintings of
+Benjamin West, who had long been a friend and protégé of Henry. He,
+too, not improbably received there the first suggestion which
+afterward led him to desert the art to which he at first devoted
+himself, and which made of the young portrait-painter a successful
+inventor and engineer. West's acquaintance with Henry had no such
+result. The young painter was led by his patron and friend to attempt
+historical pictures,[65] and probably owes his fame greatly to the
+kindly and discerning mechanic. Says Galt, in his "Memoirs of Sir
+Benjamin West" (London, 1816): "Towards his old friend, William Henry,
+of Lancaster City, he always cherished the most grateful affection;
+he was the first who urged him to attempt historical composition."
+
+  [65] Some of West's portraits, including those of Mr. and Mrs.
+  Henry, were lately in the possession of Mr. John Jordan, of
+  Philadelphia.
+
+When, after the invention of Watt, the steam-engine had taken such
+shape that it could really work the propelling apparatus of a paddle
+or screw vessel, a new impetus was given to the work of its
+adaptation. In France, the Marquis de Jouffroy was one of the earliest
+to perceive that the improvements of Watt, rendering the engine more
+compact, more powerful, and, at the same time, more regular and
+positive in its action, had made it, at last, readily applicable to
+the propulsion of vessels. The brothers Périer had imported a Watt
+engine from Soho, and this was attentively studied by the marquis,[66]
+and its application to the paddle-wheels of a steam-vessel seemed to
+him a simple problem. Comte d'Auxiron and Chevalier Charles Mounin, of
+Follenai, friends and companions of Jouffroy, were similarly
+interested, and the three are said to have often discussed the scheme
+together, and to have united in devising methods of applying the new
+motor.
+
+  [66] Figuier.
+
+In the year 1770, D'Auxiron determined to attempt the realization of
+the plans which he had conceived. He resigned his position in the
+army, prepared his plans and drawings, and presented them to M.
+Bertin, the Prime Minister, in the year 1771 or 1772. The Minister was
+favorably impressed, and the King (May 22, 1772) granted D'Auxiron a
+monopoly of the use of steam in river-navigation for 15 years,
+provided he should prove his plans practicable, and they should be so
+adjudged by the Academy.
+
+A company had been formed, the day previous, consisting of D'Auxiron,
+Jouffroy, Comte de Dijon, the Marquis d'Yonne, and Follenai, which
+advanced the requisite funds. The first vessel was commenced in
+December, 1772. When nearly completed, in September, 1774, the boat
+sprung a leak, and, one night, foundered at the wharf. After some
+angry discussion, during which D'Auxiron was rudely, and probably
+unjustly, accused of bad faith, the company declined to advance the
+money needed to recover and complete the vessel. They were, however,
+compelled by the court to furnish it; but, meantime, D'Auxiron died of
+apoplexy, the matter dropped, and the company dissolved. The cost of
+the experiment had been something more than 15,000 francs.
+
+The heirs of D'Auxiron turned the papers of the deceased inventor over
+to Jouffroy, and the King transferred to him the monopoly held by the
+former. Follenai retained all his interest in the project, and the two
+friends soon enlisted a powerful adherent and patron, the Marquis
+Ducrest, a well-known soldier, courtier, and member of the Academy,
+who took an active part in the prosecution of the scheme. M. Jacques
+Périer, the then distinguished mechanic, was consulted, and prepared
+plans, which were adopted in place of those of Jouffroy. The boat was
+built by Périer, and a trial took place in 1774, on the Seine. The
+result was unsatisfactory. The little craft could hardly stem the
+sluggish current of the river, and the failure caused the immediate
+abandonment of the scheme by Périer.
+
+Still undiscouraged, Jouffroy retired to his country home, at
+Baume-les-Dames, on the river Doubs. There he carried on his
+experiments, getting his work done as best he could, with the rude
+tools and insufficient apparatus of a village blacksmith. A Watt
+engine and a chain carrying "duck-foot" paddles were his propelling
+apparatus. The boat, which was about 14 feet long and 6 wide, was
+started in June, 1776. The duck's-foot system of paddles proved
+unsatisfactory, and Jouffroy gave it up, and renewed his experiments
+with a new arrangement. He placed on the paddle-wheel shaft a
+ratchet-wheel, and on the piston-rod of his engine, which was placed
+horizontally in the boat, a double rack, into the upper and the lower
+parts of which the ratchet-wheel geared. Thus the wheels turned in
+the same direction, whichever way the piston was moving. The new
+engine was built at Lyons in 1780, by Messrs. Frères-Jean. The new
+boat was about 140 feet long and 14 feet wide; the wheels were 14 feet
+in diameter, their floats 6 feet long, and the "dip," or depth to
+which they reached, was about 2 feet. The boat drew 3 feet of water,
+and had a total weight of about 150 tons.
+
+At a public trial of the vessel at Lyons, July 15, 1783, the little
+steamer was so successful as to justify the publication of the fact by
+a report and a proclamation. The fact that the experiment was not made
+at Paris was made an excuse on the part of the Academy for withholding
+its indorsement, and on the part of the Government for declining to
+confirm to Jouffroy the guaranteed monopoly. Impoverished and
+discouraged, Jouffroy gave up all hope of prosecuting his plans
+successfully, and reëntered the army. Thus France lost an honor which
+was already within her grasp, as she had already lost that of the
+introduction of the steam-engine, in the time of Papin.
+
+About 1785, John Fitch and James Rumsey were engaged in experiments
+having in view the application of steam to navigation.
+
+Rumsey's experiments began in 1774, and in 1786 he succeeded in
+driving a boat at the rate of four miles an hour against the current
+of the Potomac at Shepherdstown, W. Va., in presence of General
+Washington. His method of propulsion has often been reinvented since,
+and its adoption urged with that enthusiasm and persistence which is a
+peculiar characteristic of inventors.
+
+Rumsey employed his engine to drive a great pump which forced a stream
+of water aft, thus propelling the boat forward, as proposed earlier by
+Bernouilli. This same method has been recently tried again by the
+British Admiralty, in a gunboat of moderate size, using a centrifugal
+pump to set in motion the propelling stream, and with some other
+modifications which are decided improvements upon Rumsey's rude
+arrangements, but which have not done much more than his toward the
+introduction of "Hydraulic or Jet Propulsion," as it is now called.
+
+In 1787 he obtained a patent from the State of Virginia for
+steam-navigation. He wrote a treatise "On the Application of Steam,"
+which was printed at Philadelphia, where a Rumsey society was
+organized for the encouragement of attempts at steam-navigation.
+
+Rumsey died of apoplexy, while explaining some of his schemes before a
+London society a short time later, December 23, 1793, at the age of
+fifty years. A boat, then in process of construction from his plans,
+was afterward tried on the Thames, in 1793, and steamed at the rate of
+four miles an hour. The State of Kentucky, in 1839, presented his son
+with a gold medal, commemorative of his father's services "in giving
+to the world the benefit of the steamboat."
+
+JOHN FITCH was an unfortunate and eccentric, but very ingenious,
+Connecticut mechanic. After roaming about until forty years of age, he
+finally settled on the banks of the Delaware, where he built his first
+steamboat.
+
+In April, 1785, as Fitch himself states, at Neshamony, Bucks County,
+Pa., he suddenly conceived the idea that a carriage might be driven by
+steam. After considering the subject a few days, his attention was led
+to the plan of using steam to propel vessels, and from that time to
+the day of his death he was a persistent advocate of the introduction
+of the steamboat. At this time, Fitch says, "I did not know that there
+was a steam-engine on the earth;" and he was somewhat disappointed
+when his friend, the Rev. Mr. Irwin, of Neshamony, showed him a sketch
+of one in "Martin's Philosophy."
+
+Fitch's first model was at once built, and was soon after tried on a
+small stream near Davisville. The machinery was made of brass, and the
+boat was impelled by paddle-wheels. A rough model of his steamboat was
+shown to Dr. John Ewing, Provost of the University of Pennsylvania,
+who, August 20, 1785, addressed a commendatory letter to an ex-Member
+of Congress, William C. Houston, asking him to assist Fitch in
+securing the aid of the General Government. The latter referred the
+inventor, by a letter of recommendation, to a delegate from New
+Jersey, Mr. Lambert Cadwalader. With this, and other letters, Fitch
+proceeded to New York, where Congress then met, and made his
+application in proper form. He was unsuccessful, and equally so in
+attempting to secure aid from the Spanish minister, who desired that
+the profits should be secured, by a monopoly of the invention, to the
+King of Spain. Fitch declined further negotiation, determined that, if
+successful at all, the benefit should accrue to his own countrymen.
+
+In September, 1785, Fitch presented to the American Philosophical
+Society, at Philadelphia, a model in which he had substituted an
+endless chain and floats for the paddle-wheels, with drawings and a
+descriptive account of his scheme. This model is shown in the
+accompanying figure.
+
+[Illustration: FIG. 67.--Fitch's Model, 1785.]
+
+In March, 1786, Fitch was granted a patent by the State of New Jersey,
+for the exclusive right to the navigation of the waters of the State
+by steam, for 14 years. A month later, he was in Philadelphia, seeking
+a similar patent from the State of Pennsylvania. He did not at once
+succeed, but in a few days he had formed a company, raised $300, and
+set about finding a place in which to construct his engine. Henry
+Voight, a Dutch watchmaker, a good mechanic, and a very ingenious man,
+took an interest in the company, and with him Fitch set about his
+work with great enthusiasm. After making a little model, having a
+steam-cylinder but one inch in diameter, they built a model boat and
+engine, the latter having a diameter of cylinder of three inches. They
+tried the endless chain, and other methods of propulsion, without
+success, and finally succeeded with a set of oars worked by the
+engine. In August, 1786, it was determined by the company to authorize
+the construction of a larger vessel; but the money was not readily
+obtained. Meantime, Fitch continued his efforts to secure a patent
+from the State, and was finally, March 28, 1787, successful. He also
+obtained a similar grant from the State of Delaware, in February of
+the same year, and from New York, March 19.
+
+Money was now subscribed more freely, and the work on the boat
+continued uninterruptedly until May, 1787, when a trial was made,
+which revealed many defects in the machinery. The cylinder-heads were
+of wood, and leaked badly; the piston leaked; the condenser was
+imperfect; the valves were not tight. All these defects were remedied,
+and a condenser invented by Voight--the "pipe-condenser"--was
+substituted for that defective detail as previously made.
+
+The steamboat was finally placed in working order, and was found
+capable, on trial, of making three or four miles an hour. But now the
+boiler proved to be too small to furnish steam steadily in sufficient
+quantity to sustain the higher speed. After some delay, and much
+distress on the part of the sanguine inventor, who feared that he
+might be at last defeated when on the very verge of success, the
+necessary changes were finally made, and a trial took place at
+Philadelphia, in presence of the members of the Convention--then in
+session at Philadelphia framing the Federal Constitution--August 22,
+1787. Many of the distinguished spectators gave letters to Fitch
+certifying his success. Fitch now went to Virginia, where he succeeded
+in obtaining a patent, November 7, 1787, and then returned to ask a
+patent of the General Government.
+
+A controversy with Rumsey now followed, in which Fitch asserted his
+claims to the invention of the steamboat, and denied that Rumsey had
+done more than to revive the scheme which Bernouilli, Franklin, Henry,
+Paine, and others, had previously proposed, and that Rumsey's
+_steamboat_ was not made until 1786.
+
+The boiler adopted in Fitch's boat of 1787 was a "pipe-boiler," which
+he had described in a communication to the Philosophical Society, in
+September, 1785. It consisted (Fig. 68) of a small water-pipe, winding
+backward and forward in the furnace, and terminating at one end at the
+point at which the feed-water was introduced, and at the other uniting
+with the steam-pipe leading to the engine. Voight's condenser was
+similarly constructed. Rumsey claimed that this boiler was copied from
+his designs. Fitch brought evidence to prove that Rumsey had not built
+such a boiler until after his own.
+
+[Illustration: FIG. 68.--Fitch and Voight's Boiler, 1787.]
+
+[Illustration: FIG. 69.--Fitch's First Boat, 1787.]
+
+Fitch's first boat-engine had a steam-cylinder 12 inches in diameter.
+A second engine was now built (1788) with a cylinder 18 inches in
+diameter, and a new boat. The first vessel was 45 feet long and 12
+feet wide; the new boat was 60 feet long and of but 8 feet breadth of
+beam. The first boat (Fig. 69) had paddles worked at the sides, with
+the motion given the Indian paddle in propelling a canoe; in the
+second boat (Fig. 70) they were similarly worked, but were placed at
+the stern. There were three of these paddles. The boat was finally
+finished in July, 1788, and made a trip to Burlington, 20 miles from
+Philadelphia. When just reaching their destination, their boiler gave
+out, and they made their return-trip to Philadelphia floating with the
+tide. Subsequently, the boat made a number of excursions on the
+Delaware River, making three or four miles an hour.
+
+[Illustration: FIG. 70.--John Fitch, 1788.]
+
+Another of Fitch's boats, in April, 1790, made seven miles an hour.
+Fitch, writing of this boat, says that "on the 16th of April we got
+our work completed, and tried our boat again; and, although the wind
+blew very fresh at the east, we reigned lord high admirals of the
+Delaware, and no boat on the river could hold way with us." In June
+of that year it was placed as a passenger-boat on a line from
+Philadelphia to Burlington, Bristol, Bordentown, and Trenton,
+occasionally leaving that route to take excursions to Wilmington and
+Chester. During this period, the boat probably ran between 2,000 and
+3,000 miles,[67] and with no serious accident. During the winter of
+1790-'91, Fitch commenced another steamboat, the "Perseverance," and
+gave considerable time to the prosecution of his claim for a patent
+from the United States. The boat was never completed, although he
+received his patent, after a long and spirited contest with other
+claimants, on the 26th of August, 1791, and Fitch lost all hope of
+success. He went to France in 1793, hoping to obtain the privilege of
+building steam-vessels there, but was again disappointed, and worked
+his passage home in the following year.
+
+  [67] "Life of John Fitch," Westcott.
+
+[Illustration: FIG. 71.--John Fitch, 1796.]
+
+In the year 1796, Fitch was again in New York City, experimenting with
+a little _screw_ steamboat on the "Collect" Pond, which then covered
+that part of the city now occupied by the "Tombs," the city prison.
+This little boat was a ship's yawl fitted with a screw, like that
+adopted later by Woodcroft, and driven by a rudely-made engine.
+
+Fitch, while in the city of Philadelphia at about this time, met
+Oliver Evans, and discussed with him the probable future of
+steam-navigation, and proposed to form a company in the West, to
+promote the introduction of steam on the great rivers of that part of
+the country. He settled at last in Kentucky, on his land-grant, and
+there amused himself with a model steamboat, which he placed in a
+small stream near Bardstown. His death occurred there in July, 1798,
+and his body still lies in the village cemetery, with only a rough
+stone to mark the spot.
+
+Both Rumsey and Fitch endeavored to introduce their methods in Great
+Britain; and Fitch, while urging the importance and the advantages of
+his plan, confidently stated his belief that the ocean would soon be
+crossed by steam-vessels, and that the navigation of the Mississippi
+would also become exclusively a steam-navigation. His reiterated
+assertion, "The day will come when some more powerful man will get
+fame and riches from my invention; but no one will believe that poor
+John Fitch can do anything worthy of attention," now almost sounds
+like a prophecy.
+
+During this period, an interest which had never diminished in Great
+Britain had led to the introduction of experimental steamboats in that
+country. PATRICK MILLER, of Dalswinton, had commenced experimenting,
+in 1786-'87, with boats having double or triple hulls, and propelled
+by paddle-wheels placed between the parts of the compound vessel.
+James Taylor, a young man who had been engaged as tutor for Mr.
+Miller's sons, suggested, in 1787, the substitution of steam for the
+manual power which had been, up to that time, relied upon in their
+propulsion. Mr. Miller, in 1787, printed a description of his plan of
+propelling apparatus, and in it stated that he had "reason to believe
+that the power of the Steam-Engine may be applied to work the wheels."
+
+In the winter of 1787-'88, William Symmington, who had planned a new
+form of steam-engine, and made a successful working-model, was
+employed by Mr. Miller to construct an engine for a new boat. This was
+built; the little engine, having two cylinders of but four inches in
+diameter, was placed on board, and a trial was made October 14, 1788.
+The vessel (Fig. 72) was 25 feet long, of 7 feet beam, and made 5
+miles an hour.
+
+[Illustration: FIG. 72.--Miller, Taylor, and Symmington, 1788.]
+
+In the year 1789, a large vessel was built, with an engine having a
+steam-cylinder 18 inches in diameter, and this vessel was ready for
+trial in November of that year. On the first trial, the paddle-wheels
+proved too slight, and broke down; they were replaced by stronger
+wheels, and, in December, the boat, on trial, made seven miles an
+hour.
+
+Miller, like many other inventors, seems to have lost his interest in
+the matter as soon as success seemed assured, and dropped it to take
+up other incomplete plans. More than a quarter of a century later, the
+British Government gave Taylor a pension of £50 per annum, and, in
+1837, his four daughters were each given a similar annuity. Mr.
+Miller received no reward, although he is said to have expended over
+£30,000. The engine of Symmington was condemned by Miller as "the most
+improper of all steam-engines for giving motion to a vessel." Nothing
+more was done in Great Britain until early in the succeeding century.
+
+In the United States, several mechanics were now at work besides
+Fitch. Samuel Morey and Nathan Read were among these. Nicholas
+Roosevelt was another. It had just been found that American mechanics
+were able to do the required shop-work. The first experimental
+steam-engine built in America is stated to have been made in 1773 by
+Christopher Colles, a lecturer before the American Philosophical
+Society at Philadelphia. The first steam-cylinder of any considerable
+size is said[68] to have been made by Sharpe & Curtenius, of New York
+City.
+
+  [68] _Rivington's Gazette_, February 16, 1775.
+
+SAMUEL MOREY was the son of one of the first settlers of Orford, N. H.
+He was naturally fond of science and mechanics, and became something
+of an inventor. He began experimenting with the steamboat in 1790 or
+earlier, building a small vessel, and fitting it with paddle-wheels
+driven by a steam-engine of his own design, and constructed by
+himself.[69] He made a trial-trip one Sunday morning in the summer of
+1790, a friend to accompany him, from Oxford, up the Connecticut
+River, to Fairlee, Vt., a distance of several miles, and returned
+safely. He then went to New York, and spent the summer of each year
+until 1793 in experimenting with his boat and modifications of his
+engine. In 1793 he made a trip to Hartford, returning to New York the
+next summer. His boat was a "stern-wheeler," and is stated to have
+been capable of steaming five miles an hour. He next went to
+Bordentown, N. J., where he built a larger boat, which is said to have
+been a side-wheel boat, and to have worked satisfactorily. His funds
+finally gave out, and he gave up his project after having, in 1797,
+made a trip to Philadelphia. Fulton, Livingston, and Stevens met Morey
+at New York, inspected his boat, and made an excursion to Greenwich
+with him.[70] Livingston is said[71] to have offered to assist Morey
+if he should succeed in attaining a speed of eight miles an hour.
+
+  [69] _Providence Journal_, May 7, 1874. Coll., N. H. Antiquar. Soc.,
+  No. 1; "Who invented the Steamboat?" William A. Mowry, 1874.
+
+  [70] Rev. Cyrus Mann, in the _Boston Recorder_, 1858.
+
+  [71] Westcott.
+
+Morey's experiments seem to have been conducted very quietly, however,
+and almost nothing is known of them. The author has not been able to
+learn any particulars of the engines used by him, and nothing definite
+is known of the dimensions of either boat or machinery. Morey never,
+like Fitch and Rumsey, sought publicity for his plans or notoriety for
+himself.
+
+NATHAN READ, who has already been mentioned, a native of Warren,
+Mass., where he was born in the year 1759, and a graduate of Harvard
+College, was a student of medicine, and subsequently a manufacturer of
+chain-cables and other iron-work for ships. He invented, and in 1798
+patented, a nail-making machine. He was at one time (1800-1803) a
+Member of Congress, and, later, a Justice of the Court of Common
+Pleas, and Chief Justice in Hancock County, Me., after his removal to
+that State in 1807. He died in Belfast, Me., in 1849, at the age of
+ninety years.
+
+In the year 1788 he became interested in the problem of
+steam-navigation, and learned something of the work of Fitch. He first
+attempted to design a boiler that should be strong, light, and
+compact, as well as safe. His first plan was that of the "Portable
+Furnace-Boiler," as he called it; it was patented August 26, 1791. As
+designed, it consisted, as seen in Figs. 73 and 74, which are reduced
+from his patent drawings, of a shell of cylindrical form, like the now
+common vertical tubular boiler. _A_ is the furnace-door, _B_ a heater
+and feed-water reservoir, _D_ a pipe leading the feed-water into the
+boiler,[72] _E_ the smoke-pipe, and _F_ the steam-pipe leading to the
+engine. _G_ is the "shell" of the boiler, and _H_ the fire-box. The
+crown-sheet, _I I_, has depending from it, in the furnace, a set of
+water-tubes, _b b_, closed at their lower ends, and another set, _a
+a_, which connect the water-space above the furnace with the
+water-bottom, _K K_. _L_ is the furnace, and _M_ the draught-space
+between the boiler and the ash-pit, in which the grates are set.
+
+  [72] This is substantially an arrangement that has recently become
+  common. It has been repatented by later inventors.
+
+[Illustration: FIG. 73.--Read's Boiler in Section, 1788.]
+
+[Illustration: FIG. 74.--Read's Multi-Tubular Boiler, 1788.]
+
+This boiler was intended to be used in both steamboats and
+steam-carriages. The first drawings were made in 1788 or 1789, as were
+those of a peculiar form of steam-engine which also resembled very
+closely that afterward constructed in Great Britain by Trevithick.[73]
+He built a boat in 1789, which he fitted with paddle-wheels and a
+crank, which was turned by hand, and, by trial, satisfied himself that
+the system would work satisfactorily.
+
+  [73] "Nathan Read and the Steam-Engine."
+
+He then applied for his patent, and spent the greater part of the
+winter of 1789-'90 in New York, where Congress then met, endeavoring
+to secure it. In January, 1791, Read withdrew his petitions for
+patents, proposing to incorporate accounts of new devices, and renewed
+them a few months later. His patents were finally issued, dated August
+26, 1791. John Fitch, James Rumsey, and John Stevens, also, all
+received patents at the same date, for various methods of applying
+steam to the propulsion of vessels.
+
+Read appears to have never succeeded in even experimentally making his
+plans successful. He deserves credit for his early and intelligent
+perception of the importance of the subject, and for the ingenuity of
+his devices. As the inventor of the vertical multi-tubular fire-box
+boiler, he has also entitled himself to great distinction. This boiler
+is now in very general use, and is a standard form.
+
+In 1792, Elijah Ormsbee, a Rhode Island mechanic, assisted pecuniarily
+by David Wilkinson, built a small steamboat at Winsor's Cove,
+Narragansett Bay, and made a successful trial-trip on the Seekonk
+River. Ormsbee used an "atmospheric engine" and "duck's-foot" paddles.
+His boat attained a speed of from three to four miles an hour.
+
+In Great Britain, Lord Dundas and William Symmington, the former as
+the purveyor of funds and the latter as engineer, followed by Henry
+Bell, were the first to make the introduction of the steam-engine for
+the propulsion of ships so completely successful that no interruption
+subsequently took place in the growth of the new system of
+water-transportation.
+
+Thomas, Lord Dundas, of Kerse, had taken great interest in the
+experiments of Miller, and had hoped to be able to apply the new motor
+on the Forth and Clyde Canal, in which he held a large interest.
+After the failure of the earlier experiments, he did not forget the
+matter; but subsequently, meeting with Symmington, who had been
+Miller's constructing engineer, he engaged him to continue the
+experiments, and furnished all required capital, about £7,000. This
+was ten years after Miller had abandoned his scheme.
+
+Symmington commenced work in 1801. The first boat built for Lord
+Dundas, which has been claimed to have been the "first practical
+steamboat," was finished ready for trial early in 1802. The vessel was
+called the "Charlotte Dundas," in honor of a daughter of Lord Dundas,
+who became Lady Milton.
+
+[Illustration: FIG. 75.--The "Charlotte Dundas," 1801.]
+
+The vessel (Fig. 75) was driven by a Watt double-acting engine,
+turning a crank on the paddle-wheel shaft. The sectional sketch below
+exhibits the arrangement of the machinery. _A_ is the steam-cylinder,
+driving, by means of the connecting-rod, _B C_, a stern-wheel, _E E_.
+_F_ is the boiler, and _G_ the tall smoke-pipe. An air-pump and
+condenser, _H_, is seen under the steam-cylinder.
+
+In March, 1802, the boat was brought to Lock No. 20 on the Forth and
+Clyde Canal, and two vessels of 70 tons burden each taken in tow. Lord
+Dundas, William Symmington, and a party of invited guests, were taken
+on board, and the boat steamed down to Port Glasgow, a distance of
+about 20 miles, against a strong head-wind, in six hours.
+
+The proprietors of the canal were now urged to adopt the new plan of
+towing; but, fearing injury to the banks of the canal, they declined
+to do so. Lord Dundas then laid the matter before the Duke of
+Bridgewater, who gave Symmington an order for eight boats like the
+Charlotte Dundas, to be used on his canal. The death of the Duke,
+however, prevented the contract from being carried into effect, and
+Symmington again gave up the project in despair. A quarter of a
+century later, Symmington received from the British Government £100,
+and, a little later, £50 additional, as an acknowledgment of his
+services. The Charlotte Dundas was laid up, and we hear nothing more
+of that vessel.
+
+[Illustration: FIG. 76.--The "Comet," 1812.]
+
+Among those who saw the Charlotte Dundas, and who appreciated the
+importance of the success achieved by Symmington, was HENRY BELL, who,
+10 years afterward, constructed the Comet (Fig. 76), the first
+passenger-vessel built in Europe. This vessel was built in 1811, and
+completed January 18, 1812. The craft was of 30 tons burden, 40 feet
+in length, and 10-1/2 feet breadth of beam. There were _two_
+paddle-wheels on each side, driven by engines rated at three
+horse-power.
+
+Bell had, it is said, been an enthusiastic believer in the advantages
+to be secured by this application of steam, from about 1786. In 1800,
+and again in 1803, he applied to the British Admiralty for aid in
+securing those advantages by experimentally determining the proper
+form and proportions of machinery and vessel; but was not able to
+convince the Admiralty of "the practicability and great utility of
+applying steam to the propelling of vessels against winds and tides,
+and every obstruction on rivers and seas where there was depth of
+water." He also wrote to the United States Government, urging his
+views in a similar strain.
+
+Bell's boat was, when finished, advertised as a passenger-boat, to
+leave Greenock, where the vessel was built, on Mondays, Wednesdays,
+and Fridays, for Glasgow, 24 miles distant, returning Tuesdays,
+Thursdays, and Saturdays. The fare was made "four shillings for the
+best cabin, and three shillings for the second." It was some months
+before the vessel became considered a trustworthy means of conveyance.
+Bell, on the whole, was at first a heavy loser by his venture,
+although his boat proved itself a safe, stanch vessel.
+
+Bell constructed several other boats in 1815, and with his success
+steam-navigation in Great Britain was fairly inaugurated. In 1814
+there were five steamers, all Scotch, regularly working in British
+waters; in 1820 there were 34, one-half of which were in England, 14
+in Scotland, and the remainder in Ireland. Twenty years later, at the
+close of the period to which this chapter is especially devoted, there
+were about 1,325 steam-vessels in that kingdom, of which 1,000 were
+English and 250 Scotch.
+
+But we must return to America, to witness the first and most complete
+success, commercially, in the introduction of the steamboat.
+
+The Messrs. Stevens, Livingston, Fulton, and Roosevelt were there the
+most successful pioneers. The latter is said to have built the
+"Polacca," a small steamboat launched on the Passaic River in 1798.
+The vessel was 60 feet long, and had an engine of 20 inches diameter
+of cylinder and 2 feet stroke, which drove the boat 8 miles an hour,
+carrying a party of invited guests, which included the Spanish
+Minister. Livingston and John Stevens had induced Roosevelt to try
+their plans still earlier,[74] paying the expense of the experiments.
+The former adopted the plan of Bernouilli and Rumsey, using a
+centrifugal pump to force a jet of water from the stern; the latter
+used the screw. Livingston going to France as United States Minister,
+Barlow carried over the plans of the "Polacca," and Roosevelt's
+friends state that a boat built by them, in conjunction with Fulton,
+was a "sister-ship" to that vessel. In 1798, Roosevelt patented a
+double engine, having cranks set at right angles. As late as 1814 he
+received a patent for a steam-vessel, fitted with paddle-wheels having
+adjustable floats. His boat of 1798 is stated by some writers to have
+been made by him on joint account of himself, Livingston, and Stevens.
+Roosevelt, some years later, was again at work, associating himself
+with Fulton in the introduction of steam-navigation of the rivers of
+the West.[75]
+
+  [74] "Encyclopædia Americana."
+
+  [75] "A Lost Chapter in the History of the Steamboat," J. H. B.
+  Latrobe, 1871.
+
+In 1798, the Legislature of New York passed a law giving Chancellor
+Livingston the exclusive right to steam-navigation in the waters of
+the State for a period of 20 years, _provided_ that he should succeed,
+within a twelve-month, in producing a boat that should steam four
+miles an hour.
+
+Livingston did not succeed in complying with the terms of the act,
+but, in 1803, he procured the reënactment of the law in favor of
+himself and Robert Fulton, who was then experimenting in France, after
+having, in England, watched the progress of steam-navigation there,
+and then taken a patent in this country.
+
+[Illustration: Robert Fulton.]
+
+ROBERT FULTON was a native of Little Britain, Lancaster County, Pa.,
+born 1765. He commenced experimenting with paddle-wheels when a mere
+boy, in 1779, visiting an aunt living on the bank of the
+Conestoga.[76] During his youth he spent much of his time in the
+workshops of his neighborhood, and learned the trade of a watchmaker;
+but he adopted, finally, the profession of an artist, and exhibited
+great skill in portrait-painting. While his tastes were at this time
+taking a decided bent, he is said to have visited frequently the house
+of William Henry, already mentioned, to see the paintings of Benjamin
+West, who in his youth had been a kind of protégé of Mr. Henry; and he
+may probably have seen there the model steamboats which Mr. Henry
+exhibited, in 1783 or 1784, to the German traveler Schöpff. In later
+years, Thomas Paine, the author of "Common Sense," at one time lived
+with Mr. Henry, and afterward, in 1788, proposed that Congress take up
+the subject for the benefit of the country.
+
+  [76] _Vide_ "Life of Fulton," Reigart.
+
+Fulton went to England when he came of age, and studied painting with
+Benjamin West. He afterward spent two years in Devonshire, where he
+met the Duke of Bridgewater, who afterward so promptly took advantage
+of the success of the "Charlotte Dundas."
+
+While in England and in France--where he went in 1797, and resided
+some time--he may have seen something of the attempts which were
+beginning to be made to introduce steam-navigation in both of those
+countries.
+
+At about this time--perhaps in 1793--Fulton gave up painting as a
+profession, and became a civil engineer. In 1797 he went to Paris, and
+commenced experimenting with submarine torpedoes and torpedo-boats. In
+1801 he had succeeded so well with them as to create much anxiety in
+the minds of the English, then at war with France.
+
+He had, as early as 1793, proposed plans for steam-vessels, both to
+the United States and the British Governments, and seems never
+entirely to have lost sight of the subject.[77] While in France he
+lived with Joel Barlow, who subsequently became known as a poet, and
+as Embassador to France from the United States, but who was then
+engaged in business in Paris.
+
+  [77] _Vide_ "Life of Fulton," Colden.
+
+When about leaving the country, Fulton met Robert Livingston
+(Chancellor Livingston, as he is often called), who was then (1801)
+Embassador of the United States at the court of France. Together they
+discussed the project of applying steam to navigation, and determined
+to attempt the construction of a steamboat on the Seine; and in the
+early spring of the year 1802, Fulton having attended Mrs. Barlow to
+Plombières, where she had been sent by her physician, he there made
+drawings and models, which were sent or described to Livingston. In
+the following winter Fulton completed a model side-wheel boat.
+
+[Illustration: FIG. 77.--Fulton's Experiments.]
+
+January 24, 1803, he delivered this model to MM. Molar, Bordel, and
+Montgolfier, with a descriptive memoir, in which he stated that he
+had, by experiment, proven that side-wheels were better than the
+"chaplet" (paddle-floats set on an endless chain).[78] These gentlemen
+were then building for Fulton and Livingston their first boat, on
+L'Isle des Cygnes, in the Seine. In planning this boat, Fulton had
+devised many different methods of applying steam to its propulsion,
+and had made some experiments to determine the resistance of fluids.
+He therefore had been able to calculate, more accurately than had any
+earlier inventor, the relative size and proportions of boat and
+machinery.
+
+  [78] A French inventor, a watchmaker of Trévoux, named Desblancs,
+  had already deposited at the Conservatoire a model fitted with
+  "chaplets."
+
+[Illustration: FIG. 78.--Fulton's Table of Resistances.]
+
+The author has examined a large collection of Fulton's drawings, among
+which are sketches, very neatly executed, of many of these plans,
+including the chaplet, side-wheel, and stern-wheel boats, driven by
+various forms of steam-engine, some working direct, and some geared to
+the paddle-wheel shaft. Figs. 77 and 78 are engraved from two of these
+sheets. The first represents the method adopted by Fulton to determine
+the resistance of masses of wood of various forms and proportions,
+when towed through water. The other is "A Table of the resistance of
+bodies moved through water, taken from experiments made in England by
+a society for improving Naval architecture, between the years 1793 and
+1798" (Fig. 78). This latter is from a certified copy of "The Original
+Drawing on file in the Office of the Clerk of the New York District,
+making a part of the Demonstration of the patent granted to Robert
+Fulton, Esqr., on the 11th day of February, 1809. Dated this 3rd
+March, 1814," and is signed by Theron Rudd, Clerk of the New York
+District. Resistances are given in pounds per square foot.
+
+Guided by these experiments and calculations, therefore, Fulton
+directed the construction of his vessel. It was completed in the
+spring of 1803. But, unfortunately, the hull of the little vessel was
+too weak for its heavy machinery, and it broke in two and sank to the
+bottom of the Seine. Undiscouraged, Fulton at once set about repairing
+damages. He was compelled to direct the rebuilding of the hull. The
+machinery was little injured. In June, 1803, the reconstruction was
+completed, and the vessel was set afloat in July. The hull was 66 feet
+long, of 8 feet beam, and of light draught.
+
+August 9, 1803, this boat was cast loose, and steamed up the Seine, in
+presence of an immense concourse of spectators. A committee of the
+National Academy, consisting of Bougainville, Bossuet, Carnot, and
+Périer, were present to witness the experiment. The boat moved but
+slowly, making only between 3 and 4 miles an hour against the current,
+the speed through the water being about 4-1/2 miles; but this was, all
+things considered, a great success.
+
+The experiment was successful, but it attracted little attention,
+notwithstanding the fact that its success had been witnessed by the
+committee of the Academy and by many well-known savants and mechanics,
+and by officers on Napoleon's staff. The boat remained a long time on
+the Seine, near the palace. The water-tube boiler of this vessel (Fig.
+79) is still preserved at the Conservatoire des Arts et Métiers at
+Paris, where it is known as Barlow's boiler. Barlow patented it in
+France as early as 1793, as a steamboat-boiler, and states that the
+object of his construction was to obtain the greatest possible extent
+of heating-surface.
+
+Fulton endeavored to secure the pecuniary aid and the countenance of
+the First Consul, but in vain.
+
+Livingston wrote home, describing the trial of this steamboat and its
+results, and procured the passage of an act by the Legislature of the
+State of New York, extending a monopoly granted him in 1798 for the
+term of 20 years from April 5, 1803, the date of the new law, and
+extending the time allowed for proving the practicability of driving a
+boat four miles an hour by steam to two years from the same date. A
+later act further extended the time to April, 1807.
+
+[Illustration: FIG. 79.--Barlow's Water-Tube Boiler, 1793.]
+
+In May, 1804, Fulton went to England, giving up all hope of success in
+France with either his steamboats or his torpedoes. Fulton had already
+written to Boulton & Watt, ordering an engine to be built from plans
+which he furnished them; but he had not informed them of the purpose
+to which it was to be applied. This engine was to have a
+steam-cylinder 2 feet in diameter and of 4 feet stroke. The engine of
+the Charlotte Dundas was of very nearly the same size; and this fact,
+and the visit of Fulton to Symmington in 1801, as described by the
+latter, have been made the basis of a claim that Fulton was a copyist
+of the plans of others. The general accordance of the dimensions of
+his boat on the Seine with those of the "Polacca" of Roosevelt is also
+made the basis of similar claims by the friends of the latter. It
+would appear, however, that Symmington's statement is incorrect, as
+Fulton was in France, experimenting with torpedoes, at the time (July,
+1801[79]) when he is accused of having obtained from the English
+engineer the dimensions and a statement of the performance of his
+vessel. Yet a fireman employed by Symmington has made an affidavit to
+the same statement. It is evident, however, from what has preceded,
+that those inventors and builders who were at that time working with
+the object of introducing the steamboat were usually well acquainted
+with what had been done by others, and with what was being done by
+their contemporaries; and it is undoubtedly the fact that each
+profited, so far as he was able, by the experience of others.
+
+  [79] Woodcroft, p. 64.
+
+While in England, however, Fulton was certainly not so entirely
+absorbed in the torpedo experiments with which he was occupied in the
+years 1804-'6 as to forget his plans for a steamboat; and he saw the
+engine ordered by him in 1804 completed in the latter year, and
+preceded it to New York, sailing from Falmouth in October, 1806, and
+reaching the United States December 13, 1806.
+
+The engine was soon received, and Fulton immediately contracted for a
+hull in which to set it up. Meantime, Livingston had also returned to
+the United States, and the two enthusiasts worked together on a larger
+steamer than any which had yet been constructed.
+
+In the spring of 1807, the "Clermont" (Fig. 80), as the new boat was
+christened, was launched from the ship-yard of Charles Brown, on the
+East River, New York. In August the machinery was on board and in
+successful operation. The hull of this boat was 133 feet long, 18
+wide, and 9 deep. The boat soon made a trip to Albany, running the
+distance of 150 miles in 32 hours running time, and returning in 30
+hours. The sails were not used on either occasion.
+
+[Illustration: FIG. 80.--The Clermont, 1807.]
+
+This was the first voyage of considerable length ever made by a
+steam-vessel; and Fulton, though not to be classed with James Watt as
+an inventor, is entitled to the great honor of having been the first
+to make steam-navigation an every-day commercial success, and of
+having thus made the first application of the steam-engine to
+ship-propulsion, which was not followed by the retirement of the
+experimenter from the field of his labors before success was
+permanently insured.
+
+[Illustration: FIG. 81.--Engine of the Clermont, 1808.]
+
+The engine of the Clermont (Fig. 81) was of rather peculiar form, the
+piston, _E_, being coupled to the crank-shaft, _O_, by a bell-crank,
+_I H P_, and a connecting-rod, _P Q_, the paddle-wheel shaft, _M N_,
+being separate from the crank-shaft, and connected with the latter by
+gearing, _O O_. The cylinders were 24 inches in diameter by 4 feet
+stroke. The paddle-wheels had buckets 4 feet long, with a dip of 2
+feet. Old drawings, made by Fulton's own hand, and showing the engine
+as it was in 1808, and the engine of a later steamer, the Chancellor
+Livingston, are in the lecture-room of the author at the Stevens
+Institute of Technology.
+
+The voyage of the Clermont to Albany was attended by some ludicrous
+incidents, which found their counterparts wherever, subsequently,
+steamers were for the first time introduced. Mr. Colden, the
+biographer of Fulton, says that she was described, by persons who had
+seen her passing by night, "as a monster moving on the waters, defying
+wind and tide, and breathing flames and smoke."
+
+This first steamboat used dry pine wood for fuel, and the flames rose
+to a considerable distance above the smoke-pipe. When the fires were
+disturbed, mingled smoke and sparks would rise high in the air. "This
+uncommon light," says Colden, "first attracted the attention of the
+crews of other vessels. Notwithstanding the wind and tide were averse
+to its approach, they saw with astonishment that it was rapidly coming
+toward them; and when it came so near that the noise of the machinery
+and paddles was heard, the crews (if what was said in the newspapers
+of the time be true), in some instances, shrank beneath their decks
+from the terrific sight, and left their vessels to go on shore; while
+others prostrated themselves, and besought Providence to protect them
+from the approach of the horrible monster which was marching on the
+tides, and lighting its path by the fires which it vomited."
+
+In the Clermont, Fulton used several of the now characteristic
+features of the American river steamboat, and subsequently introduced
+others. His most important and creditable work, aside from that of
+the introduction of the steamboat into every-day use, was the
+experimental determination of the magnitude and the laws of
+ship-resistance, and the systematic proportioning of vessel and
+machinery to the work to be done by them.
+
+The success of the Clermont on the trial-trip was such that Fulton
+soon after advertised the vessel as a regular passenger-boat between
+New York and Albany.[80]
+
+  [80] A newspaper-slip in the scrap-book of the author has the
+  following:
+
+  "The traveler of today, as he goes on board the great steamboats St.
+  John or Drew, can scarcely imagine the difference between such
+  floating palaces and the wee-bit punts on which our fathers were
+  wafted 60 years ago. We may, however, get some idea of the sort of
+  thing then in use by a perusal of the steamboat announcements of
+  that time, two of which are as follows:
+
+  ["_Copy of an Advertisement taken from the Albany Gazette, dated
+  September, 1807._]
+
+  "The North River Steamboat will leave Pauler's Hook Ferry [now
+  Jersey City] on Friday, the 4th of September, at 9 in the morning,
+  and arrive at Albany on Saturday, at 9 in the afternoon. Provisions,
+  good berths, and accommodations are provided.
+
+  "The charge to each passenger is as follows:
+
+  "To Newburg        dols. 3,    time 14 hours.
+   "  Poughkeepsie     "   4,      "  17   "
+   "  Esopus           "   5,      "  20   "
+   "  Hudson           "   5-1/2,  "  30   "
+   "  Albany           "   7,      "  36   "
+
+  "For places, apply to William Vandervoort, No. 48 Courtlandt Street,
+  on the corner of Greenwich Street.
+
+  "_September 2, 1807._
+
+  ["_Extract from the New York Evening Post, dated October 2, 1807._]
+
+  "Mr. Fulton's new-invented _Steamboat_, which is fitted up in a neat
+  style for passengers, and is intended to run from New York to Albany
+  as a Packet, left here this morning with 90 passengers, against a
+  strong head-wind. Notwithstanding which, it was judged she moved
+  through the waters at the rate of six miles an hour."
+
+During the next winter the Clermont was repaired and enlarged, and in
+the summer of 1808 was again on the route to Albany; and, meantime,
+two new steamboats--the Raritan and the Car of Neptune--had been built
+by Fulton. In the year 1811 he built the Paragon. Both of the two
+vessels last named were of nearly double the size of the Clermont. A
+steam ferry-boat was built to ply between New York and Jersey City in
+1812, and the next year two others, to connect the metropolis with
+Brooklyn. These were "twin-boats," the two parallel hulls being
+connected by a "bridge" or deck common to both. The Jersey ferry was
+crossed in fifteen minutes, the distance being a mile and a half.
+To-day, the time occupied at the same ferry is about ten minutes.
+Fulton's ferry-boat carried, at one load, 8 carriages, and about 30
+horses, and still had room for 300 or 400 foot-passengers. Fulton also
+designed steam-vessels for use on the Western rivers, and, in 1815,
+some of his boats were started as "packets" on the line between New
+York and Providence, R. I.
+
+Meantime, the War of 1812 was in progress, and Fulton designed a steam
+vessel-of-war, which was then considered a wonderfully formidable
+craft. His plans were submitted to a commission of experienced naval
+officers, among whom were Commodores Decatur and Perry, Captain John
+Paul Jones, Captain Evans, and others whose names are still familiar,
+and were favorably commended. Fulton proposed to build a steam-vessel
+capable of carrying a heavy battery, and of steaming four miles an
+hour. The ship was to be fitted with furnaces for red-hot shot. Some
+of her guns were to be discharged below the water-line. The estimated
+cost was $320,000.
+
+The construction of the vessel was authorized by Congress in March,
+1814; the keel was laid June 20, 1814, and the vessel was launched
+October 29th of the same year.
+
+[Illustration: FIG. 82.--Launch of the "Fulton the First," 1804.]
+
+The "Fulton the First," as she was called, was considered an enormous
+vessel at that time. The hull was double, 156 feet long, 56 feet wide,
+and 20 feet deep, measuring 2,475 tons. In the following May the ship
+was ready for her engine, and in July was so far completed as to
+steam, on a trial-trip, to the ocean at Sandy Hook and back--53
+miles--in 8 hours and 20 minutes. In September of the same year, with
+armament and stores on board, the same route was traversed again, the
+vessel making 5-1/2 miles an hour. The vessel, as thus completed, had
+a double hull, each about 20 feet longer than the Clermont, and
+separated by a space 15 feet across. Her engine, having a
+steam-cylinder 48 inches in diameter and of 5 feet stroke of piston,
+was furnished with steam by a copper boiler 22 feet long, 12 feet
+wide, and 8 feet high, and turned a wheel between the two hulls which
+was 16 feet in diameter, and carried "floats" or "buckets" 14 feet
+long, and with a dip of 4 feet. The engine was in one of the two
+hulls, and the boiler in the other. The sides, at the gun-deck, were 4
+feet 10 inches thick, and her spar-deck was surrounded by heavy
+musket-proof bulwarks. The armament consisted of 30 32-pounders, which
+were intended to discharge red-hot shot. There was one heavy mast for
+each hull, fitted with large latteen sails. Each end of each hull was
+fitted with a rudder. Large pumps were carried, which were intended to
+throw heavy streams of water upon the decks of the enemy, with a view
+to disabling the foe by wetting his ordnance and ammunition. A
+submarine gun was to have been carried at each bow, to discharge shot
+weighing 100 pounds, at a depth of 10 feet below the water-line.
+
+This was the first application of the steam-engine to naval purposes,
+and, for the time, it was an exceedingly creditable one. Fulton,
+however, did not live to see the ship completed. He was engaged in a
+contest with Livingston, who was then endeavoring to obtain permission
+from the State of New Jersey to operate a line of steamboats in the
+waters of the Hudson River and New York Bay, and, while returning from
+attending a session of the Legislature at Trenton, in January, 1815,
+was exposed to the weather on the bay at a time when he was ill
+prepared to withstand it. He was taken ill, and died February 24th of
+that year. His death was mourned as a national calamity.
+
+From the above brief sketch of this distinguished man and his work, it
+is seen that, although Robert Fulton is not entitled to distinction as
+an inventor, he was one of the ablest, most persistent, and most
+successful of those who have done so much for the world by the
+introduction of the inventions of others. He was an intelligent
+engineer and an enterprising business-man, whose skill, acuteness, and
+energy have given the world the fruits of the inventive genius of all
+who preceded him, and have thus justly earned for him a fame that can
+never be lost.
+
+Fulton had some active and enterprising rivals.
+
+Oliver Evans had, in 1801 or 1802, sent one of his engines, of about
+150 horse-power, to New Orleans, for the purpose of using it to propel
+a vessel owned by Messrs. McKeever and Valcourt, which was there
+awaiting it. The engine was actually set up in the boat, but at a low
+stage of the river, and no trial could be made until the river should
+again rise, some months later. Having no funds to carry them through
+so long a period, Evans's agents were induced to remove the engine
+again, and to set it up in a saw-mill, where it created great
+astonishment by its extraordinary performance in sawing lumber.
+
+Livingston and Roosevelt were also engaged in experiments quite as
+early as Fulton, and perhaps earlier.
+
+The prize gained by Fulton was, however, most closely contested by
+Colonel JOHN STEVENS, of Hoboken, who has been already mentioned in
+connection with the early history of railroads, and who had been since
+1791 engaged in similar experiments. In 1789 he had petitioned the
+Legislature of the State of New York for a grant similar to that
+accorded to Livingston, and he then stated that his plans were
+complete, and on paper.
+
+[Illustration: FIG. 83.--Section of Steam-Boiler, 1804.]
+
+In 1804, while Fulton was in Europe, Stevens had completed a
+steamboat, 68 feet long and of 14 feet beam, which combined novelties
+and merits of design in a manner that exhibited the best possible
+evidence of remarkable inventive talent, as well as of the most
+perfect appreciation of the nature of the problem which he had
+proposed to himself to solve. Its boiler (Fig. 83) was of what is now
+known as the water-tubular variety. It was quite similar to some now
+known as sectional boilers, and contained 100 tubes 2 inches in
+diameter and 18 inches long, each fastened at one end to a central
+water-leg and steam-drum, and plugged at the other end. The flames
+from the furnace passed around and among the tubes, the water being
+inside them. The engine (Fig. 84) was a _direct-acting high-pressure_
+condensing engine, having a 10-inch cylinder, 2 feet stroke of piston,
+and drove a _screw_ having four blades, and of a form which, even
+to-day, appears quite good. The whole is a most remarkable piece of
+early engineering.
+
+[Illustration: FIG. 84.--Engine, Boiler, and Screw-Propellers used by
+Stevens, 1804.]
+
+A model of this little steamer, built in 1804, is preserved in the
+lecture-room of the Department of Mechanical Engineering at the
+Stevens Institute of Technology; and the machinery itself, consisting
+of the high-pressure "sectional" or "safety" tubular boiler, as it
+would be called to-day, the high-pressure condensing engine, with
+rotating valves, and twin screw-propellers, as just described, is
+given a place of honor in the model-room, or museum, where it
+contrasts singularly with the mechanism contributed to the collection
+by manufacturers and inventors of our own time. The hub and blade of a
+single screw, also used with the same machinery, is likewise to be
+seen there.
+
+[Illustration: FIG. 85.--Stevens's Screw Steamer, 1804.]
+
+Stevens seems to have been the first to fully recognize the importance
+of the principle involved in the construction of the sectional
+steam-boiler. His eldest son, John Cox Stevens, was in Great Britain
+in the year 1805, and, while there, patented another modification of
+this type of boiler. In his specification, he details both the method
+of construction and the principles which determine its form. He says
+that he describes this invention as it was made known to him by his
+father, and adds:
+
+"From a series of experiments made in France, in 1790, by M. Belamour,
+under the auspices of the Royal Academy of Sciences, it has been found
+that, within a certain range the elasticity of steam is nearly doubled
+by every addition of temperature equal to 30° of Fahrenheit's
+thermometer. These experiments were carried no higher than 280°, at
+which temperature the elasticity of steam was found equal to about
+four times the pressure of the atmosphere. By experiments which have
+lately been made by myself, the elasticity of steam at the temperature
+of boiling oil, which has been estimated at about 600°, was found to
+equal 40 times the pressure of the atmosphere.
+
+"To the discovery of this principle or law, which obtains when water
+assumes a state of vapor, I certainly can lay no claim; but to the
+application of it, upon certain principles, to the improvement of the
+steam-engine, I do claim exclusive right.
+
+"It is obvious that, to derive advantage from an application of this
+principle, it is absolutely necessary that the vessel or vessels for
+generating steam should have strength sufficient to withstand the
+great pressure from an increase of elasticity in the steam; but this
+pressure is increased or diminished in proportion to the capacity of
+the containing vessel. The principle, then, of this invention consists
+in forming a boiler by means of a system, or combination of a number
+of small vessels, instead of using, as in the usual mode, one large
+one; the relative strength of the materials of which these vessels
+are composed increasing in proportion to the diminution of capacity.
+It will readily occur that there are an infinite variety of possible
+modes of effecting such combinations; but, from the nature of the
+case, there are certain limits beyond which it becomes impracticable
+to carry on improvement. In the boiler I am about to describe, I
+apprehend that the improvement is carried to the utmost extent of
+which the principle is capable. Suppose a plate of brass of one foot
+square, in which a number of holes are perforated; into each of which
+holes is fixed one end of a copper tube, of about an inch in diameter
+and two feet long; and the other ends of these tubes inserted in like
+manner into a similar piece of brass; the tubes, to insure their
+tightness, to be cast in the plates; these plates are to be inclosed
+at each end of the pipes by a strong cap of cast-iron or brass, so as
+to leave a space of an inch or two between the plates or ends of the
+pipes and the cast-iron cap at each end; the caps at each end are to
+be fastened by screw-bolts passing through them into the plates; the
+necessary supply of water is to be injected by means of a forcing-pump
+into the cap at one end, and through a tube inserted into the cap at
+the other end the steam is to be conveyed to the cylinder of the
+steam-engine; the whole is then to be encircled in brickwork or
+masonry in the usual manner, placed either horizontally or
+perpendicularly, at option.
+
+"I conceive that the boiler above described embraces the most eligible
+mode of applying the principle before mentioned, and that it is
+unnecessary to give descriptions of the variations in form and
+construction that may be adopted, especially as these forms may be
+diversified in many different modes."
+
+Boilers of the character of those described in the specification given
+above were used on the locomotive built by John Stevens in 1824-'25,
+and one of them remains in the collections of the Stevens Institute of
+Technology.
+
+The use of such a boiler 70 years ago is even more remarkable than the
+adoption of the screw-propeller, in such excellent proportions, 30
+years before the labors of Smith and of Ericsson brought the screw
+into general use; and we have, in this strikingly original
+combination, as good evidence of the existence of unusual engineering
+talent in this great engineer as we found of his political and
+statesmanlike ability in his efforts to forward the introduction of
+railways.
+
+Colonel John Stevens designed a peculiar form of iron-clad in the year
+1812, which has been since reproduced by no less distinguished and
+successful an engineer than the late John Elder, of Glasgow, Scotland.
+It consisted of a saucer-shaped hull, carrying a heavy battery, and
+plated with iron of ample thickness to resist the shot fired from the
+heaviest ordnance then known. This vessel was secured to a swivel, and
+was anchored in the channel to be defended. A set of screw-propellers,
+driven by steam-engines, and situated beneath the vessel, where they
+were safe against injury by shot, were so arranged as to permit the
+vessel to be rapidly revolved about its centre. As each gun was
+brought into line of fire, it was discharged, and was then reloaded
+before coming around again. This was probably the earliest embodiment
+of the now well-established "Monitor" principle. It was probably the
+first iron-clad ever designed. It has recently been again brought out
+and introduced into the Russian navy, and is there called the
+"Popoffka."
+
+The first of Stevens's boats performed so well, that he immediately
+built another one, using the same engine as before, but employing a
+larger boiler, and propelling the vessel by _twin screws_, the latter
+being another instance of his use of a device brought forward long
+afterward as new, and frequently adopted. This boat was sufficiently
+successful to prove the practicability of making steam-navigation a
+commercial success; and Stevens, assisted by his sons, built a boat
+which he named the "Ph[oe]nix," and made the first trial in 1807, but
+just too late to anticipate Fulton. This boat was driven by
+paddle-wheels.
+
+[Illustration: FIG. 86.--Stevens's Twin-Screw Steamer, 1805.]
+
+The Ph[oe]nix, being shut out of the waters of the State of New York
+by the monopoly held by Fulton and Livingston, was used for a time
+between New York and New Brunswick, and then, anticipating a better
+pecuniary return, it was concluded to send her to Philadelphia, to ply
+on the Delaware.
+
+At that time no canal offered the opportunity to make an inland
+passage; and in June, 1808, Robert L. Stevens, a son of John, started
+with her to make the passage by sea. Although meeting a gale of wind,
+he arrived at Philadelphia safely, having been the first to trust
+himself on the open sea in a vessel relying entirely upon steam-power.
+
+From this time forward the Stevenses, father and sons, continued to
+construct steam-vessels; and, after the breaking down of the Fulton
+monopoly by the courts, they built the most successful steamboats that
+ran on the Hudson River.
+
+After Fulton and Stevens had thus led the way, steam-navigation was
+introduced very rapidly on both sides of the ocean; and on the
+Mississippi the number of boats set afloat was soon large enough to
+fulfill Evans's prediction that the navigation of that river would
+ultimately be effected by steam-vessels.
+
+The changes and improvements which, during the 20 years succeeding the
+time of Fulton and of John Stevens, gradually led to the adoption of
+the now recognized type of "American river-boat" and its steam-engine,
+were principally made by that son of the senior Stevens, who has
+already been mentioned--ROBERT L. STEVENS--and who became known later
+as the designer and builder of the first well-planned iron-clad ever
+constructed, the Stevens Battery. Much of his best work was done
+during his father's lifetime.
+
+[Illustration: Robert L. Stevens.]
+
+He made many extended and most valuable, as well as interesting,
+experiments on ship-propulsion, expending much time and large sums of
+money upon them; and many years before they became generally
+understood, he had arrived at a knowledge not only of the laws
+governing the variation of resistance at excessive speeds, but he had
+determined, and had introduced into his practice, those forms of least
+resistance and those graceful water-lines which have only recently
+distinguished the practice of other successful naval architects.
+
+Referring to his invaluable services, President King, who seems to
+have been the first to thoroughly appreciate the immense amount of
+original invention and the surprising excellence of the engineering of
+this family, in a lecture delivered in New York in 1851, gave, for the
+first time, a connected and probably accurate description of their
+work, upon which nearly all later accounts have been based.
+
+Young Stevens began working in his father's machine-shop in 1804 or
+1805, when a mere boy, and thus acquired at a very early age that
+familiarity with practical details of work and of business which is
+essential to perfect success. It was he who introduced the now common
+"hollow water-line" in the Ph[oe]nix, and thus anticipated the claims
+of the builders of the once famous "Baltimore clippers," and of the
+inventors of the "wave-line" form of vessels. In the same vessel he
+adopted a feathering paddle-wheel and the guard-beam now universally
+seen in our river steamboats.
+
+As usually constructed, this arrangement of float is as shown in Fig.
+87. The rods, _F F_, connect the eccentrically-set collar, _G_,
+carried on _H_, a pin mounted on the paddle-beam outside the wheel, or
+an eccentric secured to the vessel, with the short arms, _D D_, by
+which the paddles are turned upon the pins, _E E_. _A_ is the centre
+of the paddle-wheel, and _C C_ are arms. Circular hoops, or bands,
+connect all of the arms, each of which carries a float. They are all
+thus tied together, forming a very firm and powerful combination to
+resist external forces.
+
+[Illustration: FIG. 87.--The Feathering Paddle-Wheel.]
+
+The steamboat Philadelphia was built in the year 1813, and the young
+naval architect took advantage of the opportunity to introduce several
+new devices, including screw-bolts in place of tree-nails, and
+diagonal knees of wood and of iron. Two years later he altered the
+engines of this boat, and arranged them to work steam expansively. A
+little later he commenced using anthracite coal, which had been
+discovered in 1791 by Philip Ginter, and introduced at Wilkesbarre,
+Pa., in the smith-shops, some years before the Revolution. It had been
+used in a peculiar grate devised by Judge Fell, of that town, in 1808.
+Oliver Evans also had used it in stoves even earlier than the latter
+date, and at about the same time it had been used in the
+blast-furnace[81] at Kingston. Stevens was the first of whom we have
+record who was thoroughly successful in using, as a steam-coal, the
+new and almost unmanageable fuel. He fitted up the boiler of the
+steamboat Passaic for it in 1818, and adopted anthracite as a
+steaming-coal. He used it in a cupola-furnace in the same year, and
+its use then rapidly became general in the Eastern States.
+
+  [81] Bishop.
+
+Stevens continued his work of improving the beam-engine for many
+years. He designed the now universally-used "skeleton-beam," which is
+one of the characteristic features of the American engine, and placed
+the first example of this light and elegant, yet strong, construction
+on the steamer Hoboken in the year 1822. He built the Trenton, which
+was then considered an extraordinarily powerful, fast, and handsome
+vessel, two years afterward, and placed the two boilers on the
+guards--a custom which is still general on the river steamboats of the
+Eastern States. In this vessel he also adopted the plan of making the
+paddle-wheel floats in two parts, placing one above the other, and
+securing the upper half on the forward and the lower half on the after
+side of the arm, thus obtaining a smoother action of the wheel, and
+less loss by oblique pressures.
+
+In 1827 he built the North America (Fig. 88), one of his largest and
+most successful steamers, a vessel fitted with a pair of engines each
+44-1/2 inches in diameter of cylinder and 8 feet stroke of piston,
+making 24 revolutions per minute, driving the boat 15 to 16 miles an
+hour. Anticipating difficulty in keeping the long, light, shallow
+vessel in shape when irregularly laden, and when steaming at the high
+speed expected to be obtained when her powerful engine was exerting
+its maximum effort, he adopted the expedient of stiffening the hull by
+means of a truss of simple form. This proved thoroughly satisfactory,
+and the "hog-frame," as it has since been inelegantly but universally
+called, is still one of the peculiar features of every American
+river-steamer of any considerable size. It was in the North America,
+also, that he first introduced the artificial blast for forcing the
+fires, which is still another detail of now usual practice.
+
+[Illustration: FIG. 88.--The North America and Albany, 1827-'30.]
+
+Stevens next turned his attention to the engine again, and adopted
+spring bearings under the paddle-shaft of the New Philadelphia in
+1828, and fitted the steam-cylinder with the "double-poppet" valve,
+which is now universally used on beam-engines. This consists of two
+disk-valves, connected by the valve-spindle. The disks are of unequal
+sizes, the smaller passing through the seat of the larger. When
+seated, the pressure of the steam is, in the steam-valve, taken on the
+upper side of the larger and the lower side of the smaller disk, thus
+producing a partial balancing of the valve, and rendering it easy to
+work the heaviest engine by the hand-gear. The two valve-seats are
+formed in the top and the bottom, respectively, of the steam-passage
+leading to the cylinder; and when the valve is raised, the steam
+enters at the top and the bottom at the same time, and the two
+currents, uniting, flow together into the steam-cylinder. The same
+form of valve is used as an exhaust-valve.
+
+At about the same time he built the now standard form of return
+tubular boilers for moderate pressures. In the figure, _S_ is the
+steam and _W_ the water space, and _F_ the furnace. The direction of
+the currents of smoke and gas are shown by the arrows.
+
+[Illustration: FIG. 89.--Stevens's Return Tubular Boiler, 1832.]
+
+Some years later (1840), Stevens commenced using steam-packed pistons
+on the Trenton, in which steam was admitted by self-adjusting valves
+behind the metallic packing-rings, setting them out more effectively
+than did the steel springs then (and still) usually employed.
+
+His pistons, thus fitted, worked well for many years. A set of the
+small brass check-valves used in a piston of this kind, built by
+Stevens, and preserved in the cabinets of the Stevens Institute of
+Technology, are good evidence of the ingenuity and excellent
+workmanship which distinguished the machinery constructed under the
+direction of this great engineer.
+
+[Illustration: FIG. 90.--Stevens's Valve-Motion.]
+
+The now familiar "Stevens cut-off," a peculiar device for securing the
+expansion of steam in the steam-cylinder, was the invention (1841) of
+Robert L. Stevens and a nephew, who inherited the same constructive
+talent which distinguished the first of these great men--Mr. Francis
+B. Stevens. In this form of valve-gear, the steam and exhaust valves
+are independently worked by separate eccentrics, the latter being set
+in the usual manner, opening and closing the exhaust-passages just
+before the crank passes its centre. The steam-eccentric is so placed
+that the steam-valve is opened as usual, but closed when but about
+one-half the stroke has been made. This result is accomplished by
+giving the eccentric a greater throw than is required by the motion of
+the valve, and permitting it to move through a portion of its path
+without moving the valve. Thus, in Fig. 90, if _A B_ be the direction
+of motion of the eccentric-rod, the valve would ordinarily open the
+steam-port when the eccentric assumes the position _O C_, closing when
+the eccentric has passed around to _O D_. With the Stevens valve-gear,
+the valve is opened when the eccentric reaches _O E_, and closes when
+it arrives at _O F_. The steam-valve of the opposite end of the
+cylinder is open while the eccentric is moving from _O M_ to _O K_.
+Between _K_ and _E_, and between _F_ and _M_, both valves are seated.
+_H B_ is proportional to the lift of the valve, and _O H_ to the
+motion of the valve-gear when out of contact with the valve-lifters.
+While the crank is moving through an arc, _E F_, steam is entering the
+cylinder; from _F_ to _M_ the steam is expanding. At _M_ the stroke is
+completed, and the other steam-valve opens. The ratio (E M)/(E L) is
+the ratio of expansion.
+
+This form of cut-off motion is still a very usual one, and can be seen
+in nearly all steamers in the United States not using the device of
+Sickles. It was at about this time, also, that Stevens, having
+succeeded his father in the business of introducing the steam-engine
+in land-transportation, as well as on the water, adopted the use of
+steam expansively on the locomotives of the Camden & Amboy Railroad,
+which was controlled and built by capital furnished principally by the
+Messrs. Stevens. He at the same time constructed eight-wheeled engines
+for heavy work, and adopted anthracite coal as fuel. In the latter
+change he was thoroughly successful, and the same improvement was made
+with engines built for fast traffic in 1848.
+
+The most remarkable of all the applications of steam-power proposed by
+Robert L. Stevens was that known as the Stevens Steam Iron-Clad
+Battery. As has already been stated, Colonel John Stevens had
+proposed, as early as 1812, to build a circular or saucer-shaped
+iron-clad, like those built 60 years later for the Russian Navy.
+Nothing was done, however, although the son revived the idea in a
+modified form 20 years afterward. In the years 1813-'14, the war with
+England being then in progress, he invented, after numerous and
+hazardous experiments, an _elongated shell_, to be fired from ordinary
+smooth-bored cannon. Having perfected this invention, he sold the
+secret to the United States, after making experiments to prove their
+destructiveness so decisive as to leave no doubt of the efficacy of
+such projectiles.
+
+As early as 1837 he had perfected a plan of an iron-clad war-vessel,
+and in August, 1841, his brothers, James C. and Edwin A. Stevens,
+representing Robert L., addressed a letter to the Secretary of the
+Navy, proposing to build an iron-clad vessel of high speed, with all
+its machinery below the water-line, and having submerged
+screw-propellers. The armament was to consist of the most powerful
+rifled guns, loading at the breech, and provided with elongated shot
+and shell. In the year 1842, having contracted to build for the United
+States Government a large war-steamer on this plan, which should be
+shot and shell proof, Robert L. Stevens built a steamboat at
+Bordentown, for the sole purpose of experimenting on the forms and
+curves of propeller-blades, as compared with side-wheels, and
+continued his experiments for many months. After some delay, during
+which Mr. Stevens and his brothers were engaged with their experiments
+and in perfecting their plans, the keel of an iron-clad was laid down
+in a dry-dock which had been constructed for the purpose at great
+cost. This vessel was to have been 250 feet long, of 40 feet beam, and
+28 feet deep. The machinery was designed to furnish 700 indicated
+horse-power. The plating was proposed to be 4-1/2 inches thick--the
+same thickness of armor as was adopted 10 years later by the French
+for their comparatively rude constructions.
+
+In 1854, such marked progress had been made in the construction of
+ordnance that Mr. Stevens was no longer willing to proceed with the
+original plans, fearing that, were the ship completed, it might prove
+not invulnerable, and might throw some discredit upon its designer, as
+well as upon the navy of which it was to form a part. The work, which
+had, in those years of peace, progressed very slowly and
+intermittently, was therefore stopped entirely, the vessel given up,
+and in 1854 the keel of a ship of vastly greater size and power was
+laid down. The new design was 415 feet long, of 45 feet beam, and of
+something over 5,000 tons displacement. The thickness of armor
+proposed was 6-3/4 inches--2-1/4 inches thicker than that of the
+first French and British iron-clads--and the machinery was designed by
+Mr. Stevens to be of 8,624 indicated horse-power, driving twin-screws,
+and propelling the vessel 20 miles or more an hour. As with the
+preceding design, the progress of construction was intermittent and
+very slow. Government advanced funds, and then refused to continue the
+work; successive administrations alternately encouraged and
+discouraged the engineer; and he finally, cutting loose entirely from
+all official connections, went on with the work at his own expense.
+
+The remarkable genius of the elder Stevens was well reflected in the
+character of his son, and is in no way better exemplified than by the
+accuracy with which, in this great ship, those forms and proportions,
+both of hull and machinery, were adopted which are now, twenty-five
+years later, recognized as most correct under similar conditions. The
+lines of the vessel are beautifully fair and fine, and are what J.
+Scott Russell has called "wave-lines," or trochoidal lines, such as
+Rankine has shown to be the best possible for easy propulsion. The
+proportion of length to midship dimensions is such as to secure the
+speed proposed with a minimum resistance, and to accord closely with
+the proportions arrived at and adopted by common consent in present
+transoceanic navigation by the best--not to say radical--builders.
+
+The death of Robert L. Stevens occurred in April, 1856, when this
+larger vessel had advanced so far toward completion that the hull and
+machinery were practically finished, and it only remained to add the
+armor-plating, and to decide upon the form of fighting-house and upon
+the number and size of guns. The construction of the vessel, which had
+proceeded slowly and intermittently during the years of peace, as
+successive administrations had considered it necessary to continue the
+payment of appropriations, or had stopped temporarily in the absence
+of any apparent immediate necessity for continuance of the work, was
+again interrupted by his death.
+
+The name of Robert L. Stevens will be long remembered as that of one
+of the greatest of American mechanics, the most intelligent of naval
+architects, and as the first, and one of the greatest, of those to
+whom we are indebted for the commencement of the mightiest of
+revolutions in the methods and implements of modern naval warfare.
+American mechanical genius and engineering skill have rarely been too
+promptly recognized, and no excuse will be required for an attempt
+(which it is hoped may yet be made) to place such splendid work as
+that of the Messrs. Stevens in a light which shall reveal both its
+variety and extent and its immense importance.
+
+While Fulton was introducing the steamboat upon the waters of New York
+Bay and the Hudson River, and while the Stevenses, father and sons,
+were rapidly bringing out a fleet of steamers on the Delaware River
+and Bay, other mechanics were preparing to contest the field with them
+as opportunity offered, and as legislative acts authorizing monopoly
+expired by limitation or were repealed.
+
+About 1821, Robert L. Thurston, John Babcock, and Captain Stephen T.
+Northam, of Newport, R. I., commenced building steamboats, beginning
+with a small craft intended for use at Slade's Ferry, on an arm of
+Narragansett Bay, near Fall River. They afterward built vessels to ply
+on Long Island Sound. One of their earliest boats was the Babcock,
+built at Newport in 1826. The engine was built by Thurston and
+Babcock, at Portsmouth, R. I. They were assisted in their work by
+Richard Sanford, and with funds by Northam. The engine was of 10 or 12
+inches diameter of cylinder, and 3 or 4 feet stroke of piston. The
+boiler was a form of "pipe-boiler," subsequently (1824) patented by
+Babcock. The water used was injected into the hot boiler as fast as
+required to furnish steam, no water being retained in the
+steam-generator. This boat was succeeded, in 1827-'28, by a larger
+vessel, the Rushlight, for which the engine was built by James P.
+Allaire, at New York, while the boat was built at Newport. The boilers
+of both vessels had tubes of cast-iron. The smaller of these boats was
+of 80 tons burden; it steamed from Newport to Providence, 30 miles, in
+3-1/2 hours, and to New York, a distance of 175 miles, in 25 hours,
+using 1-3/4 cord of wood.[82] Thurston and Babcock subsequently
+removed to Providence, where the latter soon died. Thurston continued
+to build steam-engines at this place until nearly a half-century
+later, dying in 1874.[83] The establishment founded by him, after
+various changes, became the Providence Steam-Engine Works.
+
+  [82] _American Journal of Science_, March, 1827; _London Mechanics'
+  Magazine_, June 16, 1827.
+
+  [83] "New Universal Cyclopædia," vol. iv., 1878.
+
+James P. Allaire, of New York, the West Point Iron Foundery, at West
+Point, on the Hudson River, and Daniel Copeland and his son, Charles
+W. Copeland, on the Connecticut River, were also early builders of
+engines for steam-vessels. Daniel Copeland was probably the first
+(1850) to adopt a slide-valve working with a lap to secure the
+expansion of steam. His steamboats were then usually stern-wheel
+vessels, and were built to ply on several routes on the Connecticut
+River and Long Island Sound. The son, Charles W. Copeland,
+went to West Point, and while there designed some heavy marine
+steam-machinery, and subsequently designed several steam
+vessels-of-war for the United States Navy. He was the earliest
+designer of iron steamers in the United States, building the Siamese
+in 1838. This steamer was intended for use on Lake Pontchartrain and
+the canal to New Orleans. It had two hulls, was 110 feet long, and
+drew but 22 inches of water, loaded. The two horizontal non-condensing
+engines turned a single paddle-wheel placed between the two hulls,
+driving the boat 10 miles an hour. The hull was constructed of plates
+of iron 10 feet long, formed on blocks after having been heated in a
+furnace constructed especially for the purpose. The frames were of
+T-iron, which was probably here used for the first time. The same
+engineer, associated with Samuel Hart, a well-known naval constructor,
+built, in 1841, for the United States Navy, the iron steamer Michigan,
+a war-vessel intended for service on the great northern lakes. This
+vessel is still in service, and in good order. The hull is 162-1/2
+feet in length, 27 feet in breadth, and 12-1/2 feet in depth,
+measuring 500 tons. The frames were made of T-iron, stiffened by
+reverse bars of L-iron. The keel-plate was 5/8 inch thick, the bottom
+plates 3/8, and the sides 3/16 inch. The deck-beams were of iron, and
+the vessel, as a whole, was a good specimen of iron-ship building.
+
+During the period from 1830 to 1840, a considerable number of the now
+standard details of steam-engine and steamboat construction were
+devised or introduced by Copeland. He was probably the first to use
+(on the Fulton, 1840) an independent engine to drive the blowing-fans
+where an artificial draught was required. He made a practice of
+fitting his steamers with a "bilge-injection," by means of which the
+vessel could be freed of water, through the condenser and air-pump,
+when leaking seriously; the condensing-water is, in such a case, taken
+from inside the vessel, instead of from the sea. This is probably an
+American device. It was in use in the United States previously to
+1835, as was the use of anthracite coal on steamers, which was
+continued by Copeland in manufacturing and in air-furnaces, as well as
+on steamboats. He also modified the form of Stevens's double-poppet
+valve, giving it such shape that it was comparatively easy to grind it
+tight and to keep it in order.
+
+In 1825, James P. Allaire, of New York, built compound engines for the
+Henry Eckford, and subsequently constructed similar engines for
+several other steamers, one of which, the Sun, made the trip from New
+York to Albany in 12 hours 18 minutes. He used steam at 100 pounds
+pressure. Erastus W. Smith afterward introduced this form of engine on
+the Great Lakes, and still later they were introduced into British
+steamers. The machinery of the steamer Buckeye State was constructed
+at the Allaire Works, New York, in 1850, from the designs of John
+Baird and Erastus W. Smith, the latter being the designing and
+constructing engineer. The steamer was placed on the route between
+Buffalo, Cleveland, and Detroit, in 1851, and gave most satisfactory
+results, consuming less than two-thirds the fuel required by a similar
+vessel of the same line fitted with the single-cylinder engine. The
+steam-cylinders of this engine were placed one within the other, the
+low-pressure exterior cylinder being annular. They were 37 and 80
+inches in diameter respectively, and the stroke was 11 feet. Both
+pistons were connected to one cross-head, and the general arrangement
+of the engine was similar to that of the common form of beam-engine.
+The steam-pressure was from 70 to 75 pounds--about the maximum
+pressure adopted a quarter of a century later on transatlantic lines.
+This steamer was of high speed, as well as economical of fuel.
+
+In the year 1830, there were 86 steamers on the Hudson River and in
+Long Island Sound.
+
+During the early part of the nineteenth century, the introduction of
+the steamboat upon the waters of the great rivers of the interior of
+the United States was one of the most notable details of its history.
+Inaugurated by the unsuccessful experiment of Evans, the building of
+steamboats on those waters, once commenced, never ceased; and a
+generation after Fitch's burial on the shore of the Ohio, his last
+wish--that he might lie "where the song of the boatman would enliven
+the stillness of his resting-place, and the music of the steam-engine
+soothe his spirit"--was fulfilled day by day unceasingly.
+
+Nicholas J. Roosevelt was, as has been already stated, the first to
+take a steamboat down the great rivers. His boat was built at
+Pittsburgh in 1811, under an arrangement with Fulton and Livingston,
+from Fulton's plans. It was called the "New Orleans," was of about 200
+tons burden, and was propelled by a stern-wheel, assisted, when the
+winds were favorable, by sails carried on two masts. The hull was 138
+feet long, 30 feet beam, and the cost of the whole, including engines,
+was about $40,000. The builder, with his family, an engineer, a pilot,
+and six "deck-hands," left Pittsburgh in October, 1811, reaching
+Louisville in 70 hours (steaming about 10 miles an hour), and New
+Orleans in 14 days, steaming from Natchez.
+
+The next steamers built on Western waters were probably the Comet and
+the Vesuvius, both of which were in service some time. The Comet was
+finally laid aside, and the engine used to drive a mill, and the
+Vesuvius was destroyed by the explosion of her boilers. As early as
+1813 there were two shops at Pittsburgh building steam-engines.
+Steamboat-building now became an important and lucrative business in
+the West; and it is stated that as early as 1840 there were a thousand
+steamers on the Mississippi and its tributaries.
+
+In the Washington, built at Wheeling, Va., in 1816, under the
+direction of Captain Henry M. Shreve, the boilers, which had
+previously been placed in the hold, were carried on the main-deck, and
+a "hurricane-deck" was built over them. Shreve substituted two
+horizontal direct-acting engines for the single upright engine used by
+Fulton, drove them by high-pressure steam without condensation, and
+attached them, one on each side the boat, to cranks placed at right
+angles. He adopted a cam cut-off expanding the steam considerably, and
+the flue-boiler of Evans. At that time the voyage from New Orleans to
+Louisville occupied three weeks, and Shreve was made the subject of
+many witticisms when he predicted that the time would ultimately be
+shortened to ten days. It is now made in four days. The Washington was
+seized at New Orleans, in 1817, by order of Livingston, who claimed
+that his rights included the monopoly of the navigation of the
+Mississippi and its tributaries. The courts decided adversely on this
+claim, and the release of the Washington was the act which removed
+every obstacle to the introduction of steam-navigation throughout the
+United States.
+
+The first steamer on the Great Lakes was the Ontario, built in 1816,
+at Sackett's Harbor. Fifteen years later, Western steamboats had taken
+the peculiar form which has since usually distinguished them.
+
+The use of the steam-engine for ocean-navigation kept pace with its
+introduction on inland waters. Begun by Robert L. Stevens in the
+United States, in the year 1808, and by his contemporaries, Bell and
+Dodd, in Great Britain, it steadily and rapidly advanced in
+effectiveness and importance, and has now nearly driven the sailing
+fleet from the ocean. Transatlantic steam-navigation began with the
+voyage of the American steamer Savannah from Savannah, Ga., to St.
+Petersburg, Russia, _via_ Great Britain and the North-European ports,
+in the year 1819. Fulton, not long before his death, planned a vessel,
+which it was proposed to place in service in the Baltic Sea; but
+circumstances compelled a change of plan finally, and the steamer was
+placed on a line between Newport, R. I., and the city of New York; and
+the Savannah, several years later, made the voyage then proposed for
+Fulton's ship. The Savannah measured 350 tons, and was constructed by
+Crocker & Fickett, at Corlears Hook, N. Y. She was purchased by Mr.
+Scarborough, of Savannah, who placed Captain Moses Rogers, previously
+in command of the Clermont and of Stevens's boat, the Ph[oe]nix, in
+charge. The ship was fitted with steam-machinery and paddle-wheels,
+and sailed for Savannah April 27, 1819, making the voyage successfully
+in seven days. From Savannah, the vessel sailed for Liverpool May
+26th, and arrived at that port June 20th. During this trip the engines
+were used 18 days, and the remainder of the voyage was made under
+sail. From Liverpool the Savannah sailed, July 23d, for the Baltic,
+touching at Copenhagen, Stockholm, St. Petersburg, and other ports. At
+St. Petersburg, Lord Lyndock, who had been a passenger, was landed;
+and, on taking leave of the commander of the steamer, the
+distinguished guest presented him with a silver tea-kettle, suitably
+inscribed with a legend referring to the importance of the event which
+afforded him the opportunity. The Savannah left St. Petersburg in
+November, passing New York December 9th, and reaching Savannah in 50
+days from the date of departure, stopping four days at Copenhagen,
+Denmark, and an equal length of time at Arundel, Norway. Several
+severe gales were met in the Atlantic, but no serious injury was done
+to the ship.
+
+The Savannah was a full-rigged ship. The wheels were turned by an
+inclined direct-acting low-pressure engine, having a steam-cylinder 40
+inches in diameter and 6 feet stroke of piston. The paddle-wheels were
+of wrought-iron, and were so attached that they could be detached and
+hoisted on board when it was desired. After the return of the ship to
+the United States, the machinery was removed and was sold to the
+Allaire Works, of New York. The steam-cylinder was exhibited by the
+purchasers at the "World's Fair" at New York thirty years later. The
+vessel was employed, as a sailing-vessel, on a line between New York
+and Savannah, and was finally lost in the year 1822. Under sail, with
+a moderate breeze, this ship is said to have sailed about three knots,
+and to have steamed five knots. Pine-wood was used as the fuel, which
+fact accounts for the necessity of making the transatlantic voyage
+partly under sail.
+
+Renwick states that another vessel, ship-rigged and fitted with a
+steam-engine, was built at New York in 1819, to ply between New York
+and Charleston, and to New Orleans and Havana, and that it proved
+perfectly successful as a steamer, having good speed, and proving an
+excellent sea-boat. The enterprise was, however, pecuniarily a
+failure, and the vessel was sold to the Brazilian Government after the
+removal of the engine. In 1825 the steamer Enterprise made a voyage to
+India, sailing and steaming as the weather and the supply of fuel
+permitted. The voyage occupied 47 days.
+
+Notwithstanding these successful passages across the ocean, and the
+complete success of the steamboat in rivers and harbors, it was
+asserted, as late as 1838, by many who were regarded as authority,
+that the passage of the ocean by steamers was quite impracticable,
+unless possibly they could steam from the coasts of Europe to
+Newfoundland or to the Azores, and, replenishing their coal-bunkers,
+resume their voyages to the larger American ports. The voyage was,
+however, actually accomplished by two steamers in the year just
+mentioned. These were the Sirius, a ship of 700 tons and of 250
+horse-power, and the Great Western, of 1,340 tons and 450 horse-power.
+The latter was built for this service, and was a large ship for that
+time, measuring 236 feet in length. Her wheels were 28 feet in
+diameter, and 10 feet in breadth of face. The Sirius sailed from Cork
+April 4, 1838, and the Great Western from Bristol April 8th, both
+arriving at New York on the same day--April 23d--the Sirius in the
+morning, and the Great Western in the afternoon.
+
+The Great Western carried out of Bristol 660 tons of coal. Seven
+passengers chose to take advantage of the opportunity, and made the
+voyage in one-half the time usually occupied by the sailing-packets of
+that day. Throughout the voyage the wind and sea were nearly ahead,
+and the two vessels pursued the same course, under very similar
+conditions. Arriving at New York, they were received with the greatest
+possible enthusiasm. They were saluted by the forts and the men-of-war
+in the harbor; the merchant-vessels dipped their flags, and the
+citizens assembled on the Battery, and, coming to meet them in boats
+of all kinds and sizes, cheered heartily. The newspapers of the time
+were filled with the story of the voyage and with descriptions of the
+steamers themselves and of their machinery.
+
+A few days later the two steamers started on their return to Great
+Britain, the Sirius reaching Falmouth safely in 18 days, and the Great
+Western making the voyage to Bristol in 15 days, the latter meeting
+with head-winds and working, during a part of the time, against a
+heavy gale and in a high sea, at the rate of but two knots an hour.
+The Sirius was thought too small for this long and boisterous route,
+and was withdrawn and replaced on the line between London and Cork,
+where the ship had previously been employed. The Great Western
+continued several years in the transatlantic trade.
+
+Thus these two voyages inaugurated a transoceanic steam-service, which
+has steadily grown in extent and in importance. The use of steam-power
+for this work of extended ocean-transportation has never since been
+interrupted. During the succeeding six years the Great Western made 70
+passages across the Atlantic, occupying on the voyages to the westward
+an average of 15-1/2 days, and eastward 13-1/2. The quickest passage
+to New York was made in May, 1843, in 12 days and 18 hours, and the
+fastest steaming was logged 12 months earlier, when the voyage from
+New York was made in 12 days and 7 hours.
+
+Meantime, several other steamers were built and placed in the
+transatlantic trade. Among these were the Royal William, the British
+Queen, the President, the Liverpool, and the Great Britain. The
+latter, the finest of the fleet, was launched in 1843. This steamer
+was 300 feet long, 50 feet beam, and of 1,000 horse-power. The hull
+was of iron, and the whole ship was an example of the very best work
+of that time. After several voyages, this vessel went ashore on the
+coast of Ireland, and there remained several weeks, but was finally
+got off, without having suffered serious injury--a remarkable
+illustration of the stanchness of an iron hull when well built and of
+good material. The vessel was repaired, and many years afterward was
+still afloat, and engaged in the transportation of passengers and
+merchandise to Australia.
+
+The "Cunard Line" of transatlantic steamers was established in the
+year 1840. The first of the line--the Britannia--sailed from Liverpool
+for New York, July 4th of that year, and was followed, on regular
+sailing-days, by the other three of the four ships with which the
+company commenced business. These four vessels had an aggregate
+tonnage of 4,600 tons, and their speed was less than eight knots.
+To-day, the tonnage of a single vessel of the fleet exceeds that of
+the four; the total tonnage has risen to many times that above given.
+There are 50 steamers in the line, aggregating nearly 50,000
+horse-power. The speed of the steamships of the present time is double
+that of the vessels of that date, and passages are not infrequently
+made in eight days.
+
+The form of steam-engine in most general use at this time, on
+transatlantic steamers, was that known as the "side-lever engine." It
+was first given the standard form by Messrs. Maudsley & Co., of
+London, about 1835, and was built by them for steamers supplied to the
+British Government for general mail service.
+
+The steam-vessels of the time are well represented in the accompanying
+engraving (Fig. 91) of the steamship Atlantic--a vessel which was
+shortly afterward (1851) built as the pioneer steamer of the American
+"Collins Line." This steamship was one of several which formed the
+earliest of American steamship-lines, and is one of the finest
+examples of the type of paddle-steamers which was finally superseded
+by the later screw-fleets. The "Collins Line" existed but a very few
+years, and its failure was probably determined as much by the evident
+and inevitable success of screw-propulsion as by the difficulty of
+securing ample capital, complete organization, and efficient general
+management. This steamer was built at New York--the hull by William
+Brown, and the machinery by the Novelty Iron-Works. The length of the
+hull was 276 feet, its breadth 45 feet, and the depth of hold 31-1/2
+feet. The width over the paddle-boxes was 75 feet. The ship measured
+2,860 tons. The form of the hull was then peculiar in the fineness of
+its lines; the bow was sharp, and the stern fine and smooth, and the
+general outline such as best adapted the ship for high speed. The main
+saloon was about 70 feet long, and the dining-room was 60 feet in
+length and 20 feet wide. The state-rooms were arranged on each side
+the dining "saloon," and accommodated 150 passengers. These vessels
+were beautifully fitted up, and with them was inaugurated that
+wonderful system of passenger-transportation which has since always
+been distinguished by those comforts and conveniences which the
+American traveler has learned to consider his by right.
+
+[Illustration: FIG. 91.--The Atlantic, 1851.]
+
+The machinery of these ships was, for that time, remarkably powerful
+and efficient. The engines were of the side-lever type, as
+illustrated in Fig. 92, which represents the engine of the Pacific,
+designed by Mr. Charles W. Copeland, and built by the Allaire Works.
+
+[Illustration: FIG. 92.--The Side-Lever Engine, 1849.]
+
+In this type of engine, as is seen, the piston-rod was attached to a
+cross-head working vertically, from which, at each side, links, _B C_,
+connected with the "side-lever," _D E F_. The latter vibrated about a
+"main centre" at _E_, like the overhead beam of the more common form
+of engine; from its other end, a "connecting-rod," _H_, led to the
+"cross-tail," _W_, which was, in turn, connected to the crank-pin,
+_I_. The condenser, _M_, and air-pump, _Q_, were constructed in the
+same manner as those of other engines, their only peculiarities being
+such as were incident to their location between the cylinder, _A_, and
+the crank, _I J_. The paddle-wheels were of the common "radial" form,
+covered in by paddle-boxes so strongly built that they were rarely
+injured by the heaviest seas.
+
+These vessels surpassed, for a time, all other sea-going steamers in
+speed and comfort, and made their passages with great regularity. The
+minimum length of voyage of the Baltic and Pacific, of this line, was
+9 days 19 hours.
+
+During the latter part of the period the history of which has been
+here given, the marine steam-engine became subject to very marked
+changes in type and in details, and a complete revolution was effected
+in the method of propulsion. This change has finally resulted in the
+universal adoption of a new propelling instrument, and in driving the
+whole fleet of paddle-steamers from the ocean. The Great Britain was a
+screw-steamer.
+
+The screw-propeller, which, as has been stated, was probably first
+proposed by Dr. Hooke in 1681, and by Dr. Bernouilli, of Groningen, at
+about the middle of the eighteenth century, and by Watt in 1784, was,
+at the end of the century, tried experimentally in the United States
+by David Bushnell, an ingenious American, who was then conducting the
+experiments with torpedoes which were the cause of the incident which
+originated that celebrated song by Francis Hopkinson, the "Battle of
+the Kegs," using the screw to propel one of his submarine boats, and
+by John Fitch, and by Dallery in France.
+
+Joseph Bramah, of Great Britain, May 9, 1785, patented a
+screw-propeller identical in general arrangement with those used
+to-day. His sketch exhibits a screw, apparently of very fair shape,
+carried on an horizontal shaft, which passes out of the vessel through
+a stuffing-box, the screw being wholly submerged. Bramah does not seem
+to have put his plan in practice. It was patented again in England,
+also, by Littleton in 1794, and by Shorter in 1800.
+
+John Stevens, however, first gave the screw a practically useful
+form, and used it successfully, in 1804 and 1805, on the single and
+the twin screw boats which he built at that time. This propelling
+instrument was also tried by Trevithick, who planned a vessel to be
+propelled by a steam-engine driving a screw, at about this time, and
+his scheme was laid before the Navy Board in the year 1812. His plans
+included an iron hull. Francis Pettit Smith tried the screw also in
+the year 1808, and subsequently.
+
+Joseph Ressel, a Bohemian, proposed to use a screw in the propulsion
+of balloons, about 1812, and in the year 1826 proposed its use for
+marine propulsion. He is said to have built a screw-boat in the year
+1829, at Trieste, which he named the Civetta. The little craft met
+with an accident on the trial-trip, and nothing more was done.
+
+The screw was finally brought into general use through the exertions
+of John Ericsson, a skillful Swedish engineer, who was residing in
+England in the year 1836, and of Mr. F. P. Smith, an English farmer.
+Ericsson patented a peculiar form of screw-propeller, and designed a
+steamer 40 feet in length, of 8 feet beam, and drawing 3 feet of
+water. The screw was double, two shafts being placed the one within
+the other, revolving in opposite directions, and carrying the one a
+right-hand and the other a left-hand screw. These screws were 5-1/4
+feet in diameter. On her trial-trip this little steamer attained a
+speed of 10 miles an hour. Its power as a "tug" was found to be very
+satisfactory; it towed a schooner of 140 tons burden at the rate of 7
+miles, and the large American packet-ship Toronto was towed on the
+Thames at a speed of 5 miles an hour.
+
+Ericsson endeavored to interest the British Admiralty in his
+improvements, and succeeded only so far as to induce the Lords of the
+Admiralty to make an excursion with him on the river. No interest was
+awakened in the new system, and nothing was done by the naval
+authorities. A note to the inventor from Captain Beaufort--one of the
+party--was received shortly afterward, in which it was stated that
+the excursionists had not found the performance of the little vessel
+to equal their hopes and expectations. All the interests of the then
+existing engine-building establishments were opposed to the
+innovation, and the proverbial conservatism of naval men and naval
+administrations aided in procuring the rejection of Ericsson's plans.
+
+Fortunately for the United States, it happened, at that time, that we
+had in Great Britain both civil and naval representatives of greater
+intelligence, or of greater boldness and enterprise. The consul at
+Liverpool was Mr. Francis B. Ogden, of New Jersey, a gentleman who was
+somewhat familiar with the steam-engine and with steam-navigation. He
+had seen Ericsson's plans at an earlier period, and had at once seen
+their probable value. He was sufficiently confident of success to
+place capital at the disposal of the inventor. The little screw-boat
+just described was built with funds of which he furnished a part, and
+was named, in his honor, the Francis B. Ogden.
+
+Captain Robert F. Stockton, an officer of the United States Navy, and
+also a resident of New Jersey, was in London at the time, and made an
+excursion with Ericsson on the Ogden. He was also at once convinced of
+the value of the new method of application of steam-power to
+ship-propulsion, and gave the engineer an order to build two iron
+screw-steamboats for use in the United States. Ericsson was induced,
+by Messrs. Ogden and Stockton, to take up his residence in the United
+States.[84] The Stockton was sent over to the United States in April,
+1839, under sail, and was sold to the Delaware & Raritan Canal
+Company. Her name was changed, and, as the New Jersey, she remained in
+service many years.
+
+  [84] This distinguished inventor is still a resident of New York
+  (1878).
+
+The success of the boat built by Ericsson was so evident that,
+although the naval authorities remained inactive, a private company
+was formed, in 1839, to work the patents of F. P. Smith, and this
+"Ship-Propeller Company" built an experimental craft called the
+Archimedes, and its trial-trip was made October 14th of the same year.
+The speed attained was 9.64 miles an hour. The result was in every
+respect satisfactory, and the vessel, subsequently, made many voyages
+from port to port, and finally circumnavigated the island of Great
+Britain. The proprietors of the ship were not pecuniarily successful
+in their venture, however, and the sale of the vessel left the company
+a heavy loser. The Archimedes was 125 feet long, of 21 feet 10 inches
+beam, and 10 feet draught, registering 232 tons. The engines were
+rated at 80 horse-power. Smith's earlier experiments (1837) were made
+with a little craft of 6 tons burden, driven by an engine having a
+steam-cylinder 6 inches in diameter and 15 inches stroke of piston.
+The funds needed were furnished by a London banker--Mr. Wright.
+
+Bennett Woodcroft had also used the screw experimentally as early as
+1832, on the Irwell, near Manchester, England, in a boat of 55 tons
+burden. Twin-screws were used, right and left handed respectively;
+they were each two feet in diameter, and were given an expanding
+pitch. The boat attained a speed of four miles an hour.
+
+Experiments made subsequently (1843) with this form of screw, and in
+competition with the "true" screw of Smith, brought out very
+distinctly the superiority of the former, and gave some knowledge of
+the proper proportions for maximum efficiency. In later examples of
+the Woodcroft screw, the blades were made detachable and adjustable--a
+plan which is still a usual one, and which has proved to be, in some
+respects, very convenient.
+
+When Ericsson reached the United States, he was almost
+immediately given an opportunity to build the Princeton--a large
+screw-steamer--and at about the same time the English and French
+Governments also had screw-steamers built from his plans, or from
+those of his agent in England, the Count de Rosen. In these latter
+ships--the Amphion and the Pomona--the first horizontal direct-acting
+engines ever built were used, and they were fitted with double-acting
+air-pumps, having canvas valves and other novel features. The great
+advantages exhibited by these vessels over the paddle-steamers of the
+time did for screw-propulsion what Stephenson's locomotive--the
+Rocket--did for railroad locomotion ten years earlier.
+
+Congress, in 1839, had authorized the construction of three
+war-vessels, and the Secretary of the Navy ordered that two be at once
+built in the succeeding year. Of these, one was the Princeton, the
+screw-steamer of which the machinery was designed by Ericsson. The
+length of this vessel was 164 feet, beam 30-1/2 feet, and depth 21-1/2
+feet. The ship drew from 16-1/2 to 18 feet of water, displacing at
+those draughts 950 and 1,050 tons. The hull had a broad, flat floor,
+with sharp entrance and fine run, and the lines were considered at
+that time remarkably fine.
+
+The screw was of gun-bronze, six-bladed, and was 14 feet in diameter
+and of 35 feet pitch; i. e., were there no slip, the screw working as
+if in a solid nut, the ship would have been driven forward 35 feet at
+each revolution.
+
+The engines were two in number, and very peculiar in form; the
+cylinder was, in fact, a _semi_-cylinder, and the place of the
+piston-rod, as usually built, was taken by a vibrating shaft, or
+"rock-shaft," which carried a piston of rectangular form, and which
+vibrated like a door on its hinges as the steam was alternately let
+into and exhausted from each side of it. The great rock-shaft carried,
+at the outer end, an arm from which a connecting-rod led to the crank,
+thus forming a "direct-acting engine."
+
+The draught in the boilers was urged by blowers. Ericsson had adopted
+this method of securing an artificial draught ten years before, in one
+of his earlier vessels, the Corsair. The Princeton carried a XII-inch
+wrought-iron gun. This gun exploded after a few trials, with terribly
+disastrous results, causing the death of several distinguished men,
+including members of the President's cabinet.
+
+The Princeton proved very successful as a screw-steamer, attaining a
+speed of 13 knots, and was then considered very remarkably fast.
+Captain Stockton, who commanded the vessel, was most enthusiastic in
+praise of her.
+
+Immediately there began a revolution in both civil and naval
+ship-building, which progressed with great rapidity. The Princeton was
+the first of the screw-propelled navy which has now entirely displaced
+the older type of steam-vessel. The introduction of the screw now took
+place with great rapidity. Six steamers were fitted with Ericsson's
+screw in 1841, 9 in 1842, and nearly 30 in the year 1843.
+
+In Great Britain, France, Germany, and other European countries, the
+revolution was also finally effected, and was equally complete. Nearly
+all sea-going vessels built toward the close of the period here
+considered were screw-steamers, fitted with direct-acting,
+quick-working engines. It was, however, many years before the
+experience of engineers in the designing and in the construction and
+management of this new machinery enabled them to properly proportion
+it for the various kinds of service to which they were called upon to
+adapt it. Among other modifications of earlier practice introduced by
+Ericsson was the surface-condenser with a circulating pump driven by a
+small independent engine.
+
+The screw was found to possess many advantages over the paddle-wheel
+as an instrument for ship-propulsion. The cost of machinery was
+greatly reduced by its use; the expense of maintenance in working
+order was, however, somewhat increased. The latter disadvantage was,
+nevertheless, much more than compensated by an immense increase in the
+economy of ship-propulsion, which marked the substitution of the new
+instrument and its impelling machinery.
+
+When a ship is propelled by paddles, the motion of the vessel creates,
+in consequence of the friction of the fluid against the sides and
+bottom, a current of water which flows in the direction in which the
+ship is moving, and forms a current following the ship for a time, and
+finally losing all motion by contact with the surrounding mass of
+water. All the power expended in the production of this great stream
+is, in the case of the paddle-steamer, entirely lost. In
+screw-steamers, however, the propelling instrument works in this
+following current, and the tendency of its action is to bring the
+agitated fluid to rest, taking up and thus restoring, usefully, a
+large part of that energy which would otherwise have been lost. The
+screw is also completely covered by the water, and acts with
+comparative efficiency in consequence of its submersion. The rotation
+of the screw is comparatively rapid and smooth, also, and this permits
+the use of small, light, fast-running engines. The latter condition
+leads to economy of weight and space, and consequently saves not only
+the cost of transportation of the excess of weight of the larger kind
+of engine, but, leaving so much more room for paying cargo, the gain
+is found to be a double one. Still further, the quick-running engine
+is, other things being equal, the most economical of steam; and thus
+some expense is saved not only in the purchase of fuel, but in its
+transportation, and some still additional gain is derived from the
+increased amount of paying cargo which the vessel is thus enabled to
+carry. The change here described was thus found to be productive of
+enormous direct gain. Indirectly, also, some advantage was derived
+from the greater convenience of a deck clear from machinery and the
+great paddle-shaft, in the better storage of the lading, the greater
+facility with which the masts and sails could be fitted and used; and
+directly, again, in clear sides unencumbered by great paddle-boxes
+which impeded the vessel by catching both sea and wind.
+
+The screw was, for some years, generally regarded as simply auxiliary
+in large vessels, assisting the sails. Ultimately the screw became
+the essential feature, and vessels were lightly sparred and were given
+smaller areas of sail, the latter becoming the auxiliary power.
+
+In November of the year 1843, the screw-steamer Midas, Captain Poor, a
+small schooner-rigged craft, left New York for China, on probably the
+first voyage of such length ever undertaken by a steamer; and in the
+following January the Edith, Captain Lewis, a bark-rigged
+screw-vessel, sailed from the same port for India and China. The
+Massachusetts, Captain Forbes, a screw-steamship of about 800 tons,
+sailed for Liverpool September 15, 1845, the first voyage of an
+American transatlantic passenger-steamer since the Savannah's pioneer
+adventure a quarter of a century before. Two years later, American
+enterprise had placed both screw and paddle steamers on the rivers of
+China--principally through the exertions of Captain R. B. Forbes--and
+steam-navigation was fairly established throughout the world.
+
+On comparing the screw-steamer of the present time with the best
+examples of steamers propelled by paddle-wheels, the superiority of
+the former is so marked that it may cause some surprise that the
+revolution just described should have progressed no more rapidly. The
+reason of this slow progress, however, was probably that the
+introduction of the rapidly-revolving screw, in place of the
+slow-moving paddle-wheel, necessitated a complete revolution in the
+design of their steam-engines; and the unavoidable change from the
+heavy, long-stroked, low-speed engines previously in use, to the light
+engines, with small cylinders and high piston-speed, called for by the
+new system of propulsion, was one that necessarily occurred slowly,
+and was accompanied by its share of those engineering blunders and
+accidents that invariably take place during such periods of
+transition. Engineers had first to learn to design such engines
+as should be reliable under the then novel conditions of
+screw-propulsion, and their experience could only be gained through
+the occurrence of many mishaps and costly failures. The best
+proportions of engines and screws, for a given ship, were determined
+only by long experience, although great assistance was derived from
+the extensive series of experiments made with the French steamer
+Pelican. It also became necessary to train up a body of engine-drivers
+who should be capable of managing these new engines; for they required
+the exercise of a then unprecedented amount of care and skill.
+Finally, with the accomplishment of these two requisites to success
+must simultaneously occur the enlightenment of the public,
+professional as well as non-professional, in regard to their
+advantages. Thus it happens that it is only after a considerable time
+that the screw attained its proper place as an instrument of
+propulsion, and finally drove the paddle-wheel quite out of use,
+except in shoal water.
+
+Now our large screw-steamers are of higher speed than any
+paddle-steamers on the ocean, and develop their power at far less
+cost. This increased economy is due not only to the use of a more
+efficient propelling instrument, and to changes already described, but
+also, in a great degree, to the economy which has followed as a
+consequence of other changes in the steam-engine driving it. The
+earliest days of screw-propulsion witnessed the use of steam of from 5
+to 15 pounds pressure, in a geared engine using jet-condensation, and
+giving a horse-power at an expense of perhaps 7 to 10, or even more,
+pounds of coal per hour. A little later came direct-acting engines
+with jet-condensation and steam at 20 pounds pressure, costing about 5
+or 6 pounds per horse-power per hour. The steam-pressure rose a little
+higher with the use of greater expansion, and the economy of fuel was
+further improved. The introduction of the surface-condenser, which
+began to be generally adopted some ten years ago, brought down the
+cost of power to from 3 to 4 pounds in the better class of engines. At
+about the same time, this change to surface-condensation helping
+greatly to overcome those troubles arising from boiler-incrustation
+which had prevented the rise of steam-pressure above about 25 pounds
+per square inch, and as, at the same time, it was learned by engineers
+that the deposit of lime-scale in the marine boiler was determined by
+temperature rather than by the degree of concentration, and that all
+the lime entering the boiler was deposited at the pressure just
+mentioned, a sudden advance took place. Careful design, good
+workmanship, and skillful management, made the surface-condenser an
+efficient apparatus; and, the dangers of incrustation being thus
+lessened, the movement toward higher pressures recommenced, and
+progressed so rapidly that now 75 pounds per square inch is very
+usual, and more than 125 pounds has since been attained.
+
+The close of this period was marked by the construction of the most
+successful types of paddle-steamers, the complete success of
+transoceanic steam-transportation, the introduction of the
+screw-propeller and the peculiar engine appropriate to it, and,
+finally, a general improvement, which had finally become marked both
+in direction and in rapidity of movement, leading toward the use of
+higher steam-pressure, greater expansion, lighter and more
+rapidly-working machinery, and decidedly better design and
+construction, and the use of better material. The result of these
+changes was seen in economy of first cost and maintenance, and the
+ability to attain greater speed, and to assure greater safety to
+passengers and less risk to cargo.
+
+The introduction of the changes just noted finally led to the last
+great change in the form of the marine steam-engine, and a revolution
+was inaugurated, which, however, only became complete in the
+succeeding period. The non-success of Hornblower and of Wolff, and
+others who had attempted to introduce the "compound" or
+double-cylinder engine on land, had not convinced all engineers that
+it might not yet be made a successful rival of the then standard type;
+and the three or four steamers which were built for the Hudson River
+at the end of the first quarter of the nineteenth century are said to
+have been very successful vessels. Carrying 75 to 100 pounds of steam
+in their boilers, the Swiftsure and her contemporaries were by that
+circumstance well fitted to make that form of engine economically a
+success. This form of engine was built occasionally during the
+succeeding quarter of a century, but only became a recognized standard
+type after the close of the epoch to the history of which this chapter
+is devoted. That latest and greatest advance in the direction of
+increased efficiency in the marine steam-engine was, however,
+commenced very soon after Watt's death, and its completion was the
+work of nearly a half-century.
+
+[Illustration]
+
+
+
+
+CHAPTER VI.
+
+_THE STEAM-ENGINE OF TO-DAY._
+
+  ... "And, last of all, with inimitable power, and 'with whirlwind
+  sound,' comes the potent agency of steam. In comparison with the
+  past, what centuries of improvement has this single agent comprised
+  in the short compass of fifty years! Everywhere practicable,
+  everywhere efficient, it has an arm a thousand times stronger than
+  that of Hercules, and to which human ingenuity is capable of fitting
+  a thousand times as many hands as belonged to Briareus. Steam is
+  found in triumphant operation on the seas; and, under the influence
+  of its strong propulsion, the gallant ship--
+
+    'Against the wind, against the tide,
+    Still steadies with an upright keel.'
+
+  It is on the rivers, and the boatman may repose on his oars; it is
+  on highways, and exerts itself along the courses of land-conveyance;
+  it is at the bottom of mines, a thousand feet below the earth's
+  surface; it is in the mills, and in the workshops of the trades. It
+  rows, it pumps, it excavates, it carries, it draws, it lifts, it
+  hammers, it spins, it weaves, it prints. It seems to say to men, at
+  least to the class of artisans: 'Leave off your manual labor; give
+  over your bodily toil; bestow but your skill and reason to the
+  directing of my power, and I will bear the toil, with no muscle to
+  grow weary, no nerve to relax, no breast to feel faintness!' What
+  further improvement may still be made in the use of this astonishing
+  power it is impossible to know, and it were vain to conjecture. What
+  we do know is, that it has most essentially altered the face of
+  affairs, and that no visible limit yet appears beyond which its
+  progress is seen to be impossible."--DANIEL WEBSTER.
+
+
+THE PERIOD OF REFINEMENT--1850 TO DATE.
+
+By the middle of the present century, as we have now seen, the
+steam-engine had been applied, and successfully, to every great
+purpose for which it was fitted. Its first application was to the
+elevation of water; it next was applied to the driving of mills and
+machinery; and it finally became the great propelling power in
+transportation by land and by sea.
+
+At the beginning of the period to which we are now come, these
+applications of steam-power had become familiar both to the engineer
+and to the public. The forms of engine adapted to each purpose had
+been determined, and had become usually standard. Every type of the
+modern steam-engine had assumed, more or less closely, the form and
+proportions which are now familiar; and the most intelligent designers
+and builders had been taught--by experience rather than by theory, for
+the theory of the steam-engine had then been but little investigated,
+and the principles and laws of thermo-dynamics had not been traced in
+their application to this engine--the principles of construction
+essential to successful practice, and were gradually learning the
+relative standing of the many forms of steam-engine, from among which
+have been preserved a few specially fitted for certain specific
+methods of utilization of power.
+
+During the years succeeding the date 1850, therefore, the growth of
+the steam-engine had been, not a change of standard type, or the
+addition of new parts, but a gradual improvement in forms,
+proportions, and arrangements of details; and this period has been
+marked by the dying out of the forms of engine least fitted to succeed
+in competition with others, and the retention of the latter has been
+an example of "the survival of the fittest." This has therefore been a
+Period of Refinement.
+
+During this period invention has been confined to details; it has
+produced new forms of parts, new arrangements of details; it has
+devised an immense variety of valves, valve-motions, regulating
+apparatus, and a still greater variety of steam-boilers and of
+attachments, essential and non-essential, to both engines and boilers.
+The great majority of these peculiar devices have been of no value,
+and very many of the best of them have been found to have about equal
+value. All the well-known and successful forms of engine, when equally
+well designed and constructed and equally well managed, are of very
+nearly equal efficiency; all of the best-known types of steam-boiler,
+where given equal proportions of grate to heating-surface and equally
+well designed, with a view to securing a good draught and a good
+circulation of water, have been found to give very nearly equally good
+results; and it has become evident that a good knowledge of principles
+and of practice, on the part of the designer, the constructor, and the
+manager of the boiler, is essential in the endeavor to achieve
+economical success; that good engineering is demanded, rather than
+great ingenuity. The inventor has been superseded here by the
+engineer.
+
+The knowledge acquired in the time of Watt, of the essential
+principles of steam-engine construction, has since become generally
+familiar to the better class of engineers. It has led to the selection
+of simple, strong, and durable forms of engine and boiler, to the
+introduction of various kinds of valves and of valve-gearing, capable
+of adjustment to any desired range of expansive working, and to the
+attachment of efficient forms of governor to regulate the speed of the
+engine, by determining automatically the point of cut-off which will,
+at any instant, best adjust the energy exerted by the expanding steam
+to the demand made by the work to be done.
+
+The value of high pressures and considerable expansion was recognized
+as long ago as in the early part of the present century, and Watt, by
+combining skillfully the several principal parts of the steam-engine,
+gave it very nearly the shape which it has to-day. The compound
+engine, even, as has been seen, was invented by contemporaries of
+Watt, and the only important modifications since his time have
+occurred in details. The introduction of the "drop cut-off," the
+attachment of the governor to the expansion-apparatus in such a manner
+as to determine the degree of expansion, the improvement of
+proportions, the introduction of higher steam and greater expansion,
+the improvement of the marine engine by the adoption of
+surface-condensation, in addition to these other changes, and the
+introduction of the double-cylinder engine, after the elevation of
+steam-pressure and increase of expansion had gone so far as to justify
+its use, are the changes, therefore, which have taken place during
+this last quarter-century. It began then to be generally understood
+that expansion of steam produced economy, and mechanics and inventors
+vied with each other in the effort to obtain a form of valve-gear
+which should secure the immense saving which an abstract consideration
+of the expansion of gases according to Marriotte's law would seem to
+promise. The counteracting phenomena of internal condensation and
+reëvaporation, of the losses of heat externally and internally, and of
+the effect of defective vacuum, defective distribution of steam, and
+of back-pressure, were either unobserved or were entirely overlooked.
+
+It was many years, therefore, before engine-builders became convinced
+that no improvement upon existing forms of expansion-gear could secure
+even an approximation to theoretical efficiency.
+
+The fact thus learned, that the benefit of expansive working has a
+limit which is very soon reached in ordinary practice, was not then,
+and has only recently become, generally known among our steam-engine
+builders, and for several years, during the period upon which we now
+enter, there continued the keenest competition between makers of rival
+forms of expansion-gear, and inventors were continually endeavoring to
+produce something which should far excel any previously-existing
+device.
+
+In Europe, as in the United States, efforts to "improve" standard
+designs have usually resulted in injuring their efficiency, and in
+simply adding to the first cost and running expense of the engines,
+without securing a marked increase in economy in the consumption of
+steam.
+
+
+SECTION I.--STATIONARY ENGINES.
+
+"STATIONARY ENGINES" had been applied to the operation of
+mill-machinery, as has been seen, by Watt and by Murdoch, his
+assistant and pupil; and Watt's competitors, in Great Britain and
+abroad, had made considerable progress before the death of the great
+engineer, in its adaptation to its work. In the United States, Oliver
+Evans had introduced the non-condensing high-pressure stationary
+engine, which was the progenitor of the standard engine of that type
+which is now used far more generally than any other form. These
+engines were at first rude in design, badly proportioned, rough and
+inaccurate as to workmanship, and uneconomical in their consumption of
+fuel. Gradually, however, when made by reputable builders, they
+assumed neat and strong shapes, good proportions, and were well made
+and of excellent materials, doing their work with comparatively little
+waste of heat or of fuel.
+
+One of the neatest and best modern designs of stationary engine for
+small powers is seen in Fig. 93, which represents a "vertical
+direct-acting engine," with base-plate--a form which is a favorite
+with many engineers.
+
+The engine shown in the engraving consists of two principal parts, the
+cylinder and the frame, which is a tapering column having openings in
+the sides, to allow free access to all the working parts within. The
+slides and pillow-blocks are cast with the column, so that they cannot
+become loose or out of line; the rubbing surfaces are large and easily
+lubricated. Owing to the vertical position, there is no tendency to
+side wear of cylinder or piston. The packing-rings are self-adjusting,
+and work free but tight. The crank is counterbalanced; the crank-pin,
+cross-head pin, piston-rod, valve-stem, etc., are made of steel; all
+the bearing surfaces are made extra large, and are accurately fitted;
+and the best quality of Babbitt-metal only used for the
+journal-bearings.
+
+[Illustration: FIG. 93.--Vertical Stationary Steam-Engine.]
+
+The smaller sizes of these engines, from 2 to 10 horse-power, have
+both pillow-blocks cast in the frame, giving a bearing each side of
+the double cranks. They are built by some constructors in quantities,
+and parts duplicated by special machinery (as in fire-arms and
+sewing-machines), which secures great accuracy and uniformity of
+workmanship, and allows of any part being quickly and cheaply
+replaced, when worn or broken by accident. The next figure is a
+vertical section through the same engine.
+
+[Illustration: FIG. 94.--Vertical Stationary Steam-Engine. Section.]
+
+Engines fitted with the ordinary rigid bearings require to be erected
+on a firm foundation, and to be kept in perfect line. If, by the
+settling of the foundation, or from any other cause, they get out of
+line, heating, cutting, and thumping result. To obviate this, modern
+engines are often fitted with self-adjusting bearings throughout; this
+gives the engine great flexibility and freedom from friction. The
+accompanying cuts show clearly how this is accomplished. The
+pillow-block has a spherical shell turned and fitted into the
+spherically-bored pillow-block, thus allowing a slight angular motion
+in any direction. The connecting-rod is forged in a single piece,
+without straps, gibs, or key, and is mortised through at each end for
+the reception of the brass boxes, which are curved on their backs, and
+fit the cheek-pieces, between which they can turn to adjust themselves
+to the pins, in the plane of the axis of the rod. The adjustment for
+wear is made by wedge-blocks and set screws, as shown, and they are so
+constructed that the parts cannot get loose and cause a break-down.
+The cross-head has adjustable gibs on each side, turned to fit the
+slides, which are cast solidly in the frame, and bored out exactly in
+the line with the cylinder. This permits it freely to turn on its
+axis, and, in connection with the adjustable boxes in the
+connecting-rod, allows a perfect self-adjustment to the line of the
+crank-pin. The out-board bearing may be moved an inch or more out of
+position in any direction, without detriment to the running of the
+engine, all bearings accommodating themselves perfectly to whatever
+position the shaft may assume.
+
+The ports and valve-passages are proportioned as in locomotive
+practice. The valve-seat is adapted to the ordinary plain slide or
+D-valve, should it be preferred, but the balanced piston slide-valve
+works with equal ease whether the steam-pressure is 10 or 100 pounds,
+and at the same time gives double steam and exhaust openings, which
+greatly facilitates the entrance of the steam to, and its escape from,
+the cylinder, thus securing a nearer approach to boiler-pressure and a
+less back-pressure, saving the power required to work an ordinary
+valve, and reducing the wear of valve-gear.
+
+This is a type of engine frequently seen in the United States, but
+more rarely in Europe. It is an excellent form of engine. The vertical
+direct-acting engine is sometimes, though rarely, built of very
+considerable size, and these large engines are more frequently seen in
+rolling-mills than elsewhere.
+
+Where much power is required, the stationary engine is usually an
+horizontal direct-acting engine, having a more or less effective
+cut-off valve-gear, according to the size of engine and the cost of
+fuel. A good example of the simpler form of this kind of engine is the
+small horizontal slide-valve engine, with independent cut-off valve
+riding on the back of the main valve--a combination generally known
+among engineers as the Meyer system of valve-gear. This form of
+steam-engine is a very effective machine, and does excellent work when
+properly proportioned to yield the required amount of power. It is
+well adapted to an expansion of from four to five times. Its
+disadvantages are the difficulty which it presents in the attachment
+of the regulator, to determine the point of cut-off by the heavy work
+which it throws upon the governor when attached, and the rather
+inflexible character of the device as an expansive valve-gear. The
+best examples of this class of engine have neat heavy bed-plates,
+well-designed cylinders and details, smooth-working valve-gear, the
+expansion-valve adjusted by a right and left hand screw, and
+regulation secured by the attachment of the governor to the
+throttle-valve.
+
+The engine shown in the accompanying illustration (Fig. 95) is an
+example of an excellent British stationary steam-engine. It is simple,
+strong, and efficient. The frame, front cylinder-head, cross-head
+guides, and crank-shaft "plumber-block," are cast in one piece, as has
+so generally been done in the United States for a long time by some of
+our manufacturers. The cylinder is secured against the end of the
+bed-plate, as was first done by Corliss. The crank-pin is set in a
+counterbalanced disk. The valve-gear is simple, and the governor
+effective, and provided with a safety-device to prevent injury by the
+breaking of the governor-belt. An engine of this kind of 10 inches
+diameter of cylinder, 20 inches stroke of piston, is rated by the
+builders at about 25 horse-power; a similar engine 30 inches in
+diameter of cylinder would yield from 225 to 250 horse-power. In
+this example, all parts are made to exact size by gauges standardized
+to Whitworth's sizes.
+
+[Illustration: FIG. 95.--Horizontal Stationary Steam-Engine.]
+
+[Illustration: FIG. 96.--Horizontal Stationary Steam-Engine.]
+
+In American engines (as is seen in Fig. 96), usually, two supports are
+placed--the one under the latter bearing, and the other under the
+cylinder--to take the weight of the engine; and through them it is
+secured to the foundation. As in the vertical engine already
+described, a valve is sometimes used, consisting of two pistons
+connected by a rod, and worked by an ordinary eccentric. By a simple
+arrangement these pistons have always the same pressure inside as out,
+which prevents any leakage or blowing through; and they are said
+always to work equally as well and free from friction under 150 pounds
+pressure as under 10 pounds per square inch, and to require no
+adjustment. It is more usual, however, to adopt the three-ported valve
+used on locomotives, with (frequently) a cut-off valve on the back of
+this main valve, which cut-off valve is adjusted either by hand or by
+the governor.
+
+Engines of the class just described are especially well fitted, by
+their simplicity, compactness, and solidity, to work at the high
+piston-speeds which are gradually becoming generally adopted in the
+effort to attain increased economy of fuel by the reduction of the
+immense losses of heat which occur in the expansion of steam in the
+metallic cylinders through which we are now compelled to work it.
+
+One of the best known of recent engines is the Allen engine, a
+steam-engine having the same general arrangement of parts seen in the
+above illustration, but fitted with a peculiar valve-gear, and having
+proportions of parts which are especially calculated to secure
+smoothness of motion and uniformity of pressure on crank-pin and
+journals, at speeds so high that the inertia of the reciprocating
+parts becomes a seriously-important element in the calculation of the
+distribution of stresses and their effect on the dynamics of the
+machine.
+
+In the Allen engine,[85] the cylinder and frame are connected as in
+the engine seen above, and the crank-disk, shaft-bearings, and other
+principal details, are not essentially different. The valve-gear[86]
+differs in having four valves, one at each end on the steam as well as
+on the exhaust side, all of which are balanced and work with very
+little resistance. These valves are not detachable, but are driven by
+a link attached to and moved by an eccentric on the main shaft, the
+position of the valve-rod attachment to which link is determined by
+the governor, and the degree of expansion is thus adjusted to the work
+of the engine. The engine has usually a short stroke, not exceeding
+twice the diameter of cylinder, and is driven at very high speed,
+generally averaging from 600 to 800 feet per minute.[87] This high
+piston-speed and short stroke give very great velocity of rotation.
+The effect is, therefore, to produce an exceptional smoothness of
+motion, while permitting the use of small fly-wheels. Its short stroke
+enables entire solidity to be attained in a bed of rigid form, making
+it a very completely self-contained engine, adapted to the heaviest
+work, and requiring only a small foundation.
+
+  [85] The invention of Messrs. Charles T. Porter and John F. Allen.
+
+  [86] Invented by Mr. John F. Allen.
+
+  [87] Or not far from 600 times the cube root of the length of
+  stroke, measured in feet.
+
+The journals of the shaft, and all cylindrical wearing surfaces, are
+finished by grinding in a manner that leaves them perfectly round. The
+crank-pin and cross-head pin are hardened before being ground. The
+joints of the valve-gear consist of pins turning in solid ferrules in
+the rod-ends, both hardened and ground. After years of constant use
+thus, no wear occasioning lost time in the valve-movements has been
+detected.
+
+High speed and short strokes are essential elements of economy. It is
+now well understood that all the surfaces with which the steam comes
+in contact condense it.
+
+Obviously, one way to diminish this loss is to reduce the extent of
+surface to which the steam is exposed. In engines of high speed and
+short stroke, the surfaces with which the steam comes in contact,
+while doing a given amount of work, present less area than in ordinary
+engines running at low speed. Where great steadiness of motion is
+desired, the expense of coupled engines is often incurred.
+Quick-running engines do not require to be coupled; a single engine
+may give greater uniformity of motion than is usually obtained with
+coupled engines at ordinary speeds. The ports and valve-movements, the
+weight of the reciprocating parts, and the size and weight of the
+fly-wheels, should be calculated expressly for the speeds chosen.
+
+The economy of the engine here described is unexcelled by the best of
+the more familiar "drop cut-off" engines.
+
+An engine reported upon by a committee of the American Institute, of
+which Dr. Barnard was chairman, was non-condensing, 16 inches in
+diameter of cylinder, 30 inches stroke, making 125 revolutions per
+minute, and developed over 125 horse-power with 75 pounds of steam in
+the boiler, using 25-3/4 pounds of steam per indicated horse-power,
+and 2.87 pounds of coal--an extraordinarily good performance for an
+engine of such small power.
+
+The governor used on this engine is known as the Porter governor. It
+is given great power and delicacy by weighting it down, and thus
+obtaining a high velocity of rotation, and by suspending the balls
+from forked arms, which are given each two bearing-pins separated
+laterally so far as to permit considerable force to be exerted in
+changing speeds without cramping those bearings sufficiently to
+seriously impair the sensitiveness of the governor. This engine as a
+whole may be regarded as a good representative of the high-speed
+engine of to-day.
+
+Since this change in the direction of high speeds has already gone so
+far that the "drop cut-off" is sometimes inapplicable, in consequence
+of the fact that the piston would, were such a valve-gear adopted,
+reach the end of its stroke before the detached valve could reach its
+seat; and since this progress is only limited by our attainments in
+mechanical skill and accuracy, it seems probable that the
+"positive-motion expansion-gear" type of engine will ultimately
+supersede the now standard "drop cut-off engine."
+
+The best known and most generally used class of stationary engines at
+the present time is, however, that which has the so-called "drop
+cut-off," or "detachable valve-gear." The oldest well-known form of
+valve-motion of this description now in use is that known as the
+Sickels cut-off, patented by Frederick E. Sickels, an American
+mechanic, about the year 1841, and also built by Hogg, of New York,
+who placed it upon the engine of the steamer South America. The
+invention is claimed for both Hogg and Sickels. It was introduced by
+the inventor in a form which especially adapted it to use with the
+beam-engine used on the Eastern waters of the United States, and was
+adapted to stationary engines by Messrs. Thurston, Greene & Co., of
+Providence, R. I., who made use of it for some years before any other
+form of "drop cut-off" came into general use. The Sickels cut-off
+consisted of a set of steam-valves, usually independent of the
+exhaust-valves, and each raised by a catch, which could be thrown out,
+at the proper moment, by a wedge with which it came in contact as it
+rose with the opening valve. This wedge, or other equivalent device,
+was so adjusted that the valve should be detached and fall to its seat
+when the piston reached that point in its movement, after taking
+steam, at which expansion was to commence. From this point, no steam
+entering the cylinder, the piston was impelled by the expanding vapor.
+The valve was usually the double-poppet. Sickels subsequently invented
+what was called the "beam-motion," to detach the valve at any point in
+the stroke. As at first arranged, the valve could only be detached
+during the earlier half-stroke, since at mid-stroke the direction of
+motion of the eccentric rod was reversed and the valve began to
+descend. By introducing a "wiper" having a motion transverse to that
+of the valve and its catch, and by giving this wiper a motion
+coincident with that of the piston by connecting it with the beam or
+other part of the engine moving with the piston, he obtained a
+kinematic combination which permitted the valve to be detached at any
+point in the stroke, adding a very simple contrivance which enabled
+the attendant to set the wiper so that it should strike the catch at
+any time during the forward movement of the "beam-motion."
+
+On stationary engines, the point of cut-off was afterward determined
+by the governor, which was made to operate the detaching mechanism,
+the combination forming what is sometimes called an "automatic"
+cut-off. The attachment of the governor so as to determine the degree
+of expansion had been proposed before Sickels's time. One of the
+earliest of these contrivances was that of Zachariah Allen, in 1834,
+using a cut-off valve independent of the steam-valve. The first to so
+attach the governor to a _drop cut-off_ valve-motion was George H.
+Corliss, who made it a feature of the Corliss valve-gear in 1849. In
+the year 1855, N. T. Greene introduced a form of expansion-gear, in
+which he combined the range of the Sickels beam-motion device with the
+expansion-adjustment gained by the attachment of the governor, and
+with the advantages of flat slide-valves at all ports--both steam and
+exhaust.
+
+Many other ingenious forms of expansion valve-gear have been invented,
+and several have been introduced, which, properly designed and
+proportioned to well-planned engines, and with good construction and
+management, should give economical results little if at all inferior
+to those just named. Among the most ingenious of these later devices
+is that of Babcock & Wilcox, in which a very small auxiliary
+steam-cylinder and piston is employed to throw the cut-off valve over
+its port at the instant at which the steam is to be cut off. A very
+beautiful form of isochronous governor is used on this engine, to
+regulate the speed of the engine by determining the point of cut-off.
+
+In Wright's engine, the expansion is adjusted by the movement, by the
+regulator, of cams which operate the steam-valves so that they shall
+hold the valve open a longer or shorter time, as required.
+
+Since compactness and lightness are not as essential as in portable,
+locomotive, and marine engines, the parts are arranged, in stationary
+engines, with a view simply to securing efficiency, and the design is
+determined by circumstances. It was formerly usual to adopt the
+condensing engine in mills, and wherever a stationary engine was
+required. In Europe generally, and to some extent in the United
+States, where a supply of condensing water is obtainable, condensing
+engines and moderate steam-pressures are still employed. But this type
+of engine is gradually becoming superseded by the high-pressure
+condensing engine, with considerable expansion, and with an
+expansion-gear in which the point of cut-off is determined by the
+governor.
+
+[Illustration: FIG. 97.--Corliss Engine.]
+
+[Illustration: FIG. 98--Corliss Engine Valve-Motion.]
+
+The best-known engine of this class is the Corliss engine, which is
+very extensively used in the United States, and which has been copied
+very generally by European builders. Fig. 97 represents the Corliss
+engine. The horizontal steam-cylinder is bolted firmly to the end of
+the frame, which is so formed as to transmit the strain to the main
+journal with the greatest directness. The frame carries the guides for
+the cross-head, which are both in the same vertical plane. The valves
+are four in number, a steam and an exhaust valve being placed at each
+end of the steam-cylinder. Short steam-passages are thus secured, and
+this diminution of clearance is a source of some economy. Both sets of
+valves are driven by an eccentric operating a disk or wrist-plate, _E_
+(Fig. 98), which vibrates on a pin projecting from the cylinder. Short
+links reaching from this wrist-plate to the several valves, _D D_, _F
+F_, move them with a peculiarly varying motion, opening and closing
+them rapidly, and moving them quite slowly when the port is either
+nearly open or almost closed. This effect is ingeniously secured by so
+placing the pins on the wrist-plate that their line of motion becomes
+nearly transverse to the direction of the valve-links when the limit
+of movement is approached. The links connecting the wrist-plate with
+the arms moving the steam-valves have catches at their extremities,
+which are disengaged by coming in contact, as the arm swings around
+with the valve-stem, with a cam adjusted by the governor. This
+adjustment permits the steam to follow the piston farther when the
+engine is caused to "slow down," and thus tends to restore the proper
+speed. It disengages the steam-valve earlier, and expands the steam to
+a greater extent, when the engine begins to run above the proper
+speed. When the catch is thrown out, the valve is closed by a weight
+or a strong spring. To prevent jar when the motion of the valve is
+checked, a "dash-pot" is used, invented originally by F. E. Sickels.
+This is a vessel having a nicely-fitted piston, which is received by a
+"cushion" of water or air when the piston suddenly enters the cylinder
+at the end of the valve-movement. In the original water dash-pot of
+Sickels, the cylinder is vertical, and the plunger or piston descends
+upon a small body of water confined in the base of the dash-pot.
+Corliss's air dash-pot is now often set horizontally.
+
+[Illustration: FIG. 99.--Greene Engine.]
+
+In the Greene steam-engine (Fig. 99), the valves are four in number,
+as in the Corliss. The cut-off gear consists of a bar, _A_, moved by
+the steam-eccentric in a direction parallel with the centre-line of
+the cylinder and nearly coincident as to time with the piston. On this
+bar are tappets, _C C_, supported by springs and adjustable in height
+by the governor, _G_. These tappets engage the arms _B B_, on the ends
+of rock-shafts, _E E_, which move the steam-valves and remain in
+contact with them a longer or shorter time, and holding the valve open
+during a greater or less part of the piston-stroke, as the governor
+permits the tappets to rise with diminishing engine-speed, or forces
+them down as speed increases. The exhaust-valves are moved by an
+independent eccentric rod, which is itself moved by an eccentric set,
+as is usual with the Corliss and with other engines generally, at
+right angles with the crank. This engine, in consequence of the
+independence of the steam-eccentric, and of the contemporary movement
+of steam valve-motion and steam-piston, is capable of cutting off at
+any point from beginning to nearly the end of the stroke. The usual
+arrangement, by which steam and exhaust valves are moved by the same
+eccentric, only permits expansion with the range from the beginning to
+half-stroke. In the Corliss engine the latter construction is
+retained, with the object, in part, of securing a means of closing the
+valve by a "positive motion," should, by any accident, the closing not
+be effected by the weight or spring usually relied upon.
+
+[Illustration: FIG. 100.--Thurston's Greene-Engine Valve-Gear.]
+
+The steam-valve of the Greene engine, as designed by the author, is
+seen in Fig. 100, where the valve, _G H_, covering the port, _D_, in
+the steam-cylinder, _A B_, is moved by the rod, _J J_, connected to
+the rock-shaft, _M_, by the arm, _L K_. The line, _K I_, should, when
+carried out, intersect the valve-face at its middle point, under _G_.
+
+The characteristics of the American stationary engine, therefore, are
+high steam-pressure without condensation, an expansion valve-gear with
+drop cut-off adjustable by the governor, high piston-speed, and
+lightness combined with strength of construction. The pressure most
+commonly adopted in the boilers which furnish steam to this type of
+engine is from 75 to 80 pounds per square inch; but a pressure of 100
+pounds is not infrequently carried, and the latter pressure may be
+regarded as a "mean maximum," corresponding to a pressure of 60 pounds
+at about the commencement of the period here considered--1850.
+
+Very much greater pressures have, however, been adopted by some
+makers, and immensely "higher steam" has been experimented with by
+several engineers. As early as 1823, Jacob Perkins[88] commenced
+experimenting with steam of very great tension. As has already been
+stated, the usual pressure at the time of Watt was but a few pounds--5
+or 7--in excess of that of the atmosphere. Evans, Trevithick, and
+Stevens, had previously worked steam at pressures of from 50 to 75
+pounds per square inch, and pressures on the Western rivers and
+elsewhere in the United States had already been raised to 100 or 150
+pounds, and explosions were becoming alarmingly frequent.
+
+  [88] Perkins was a native of Newburyport, Mass. He was born July 9,
+  1766, and died in London, July 30, 1849. He went to England when
+  fifty-two years of age, to introduce his inventions.
+
+Perkins's experimental apparatus consisted of a copper boiler, of a
+capacity of about one cubic foot, having sides 3 inches in thickness.
+It was closed at the bottom and top, and had five small pipes leading
+from the upper head. This was placed in a furnace kept at a high
+temperature by a forced combustion. Safety-valves loaded respectively
+to 425 and 550 pounds per square inch were placed on each of two of
+the steam-pipes.
+
+Perkins used the steam generated under these great pressures in a
+little engine having a piston 2 inches in diameter and a stroke of 1
+foot. It was rated at 10 horse-power.[89]
+
+  [89] It was when writing of this engine that Stuart wrote, in 1824:
+  "Judging from the rapid strides the steam-engine has made _during
+  the last forty years_ to become a universal first-mover, and from
+  the experience that has arisen from that extension, we feel
+  convinced that every invention which diminishes its size without
+  impairing its power brings it a step nearer to the assistance of the
+  'world's great laborers,' the husbandman and the peasant, for whom,
+  as yet, it performs but little. At present, it is made occasionally
+  to tread out the corn. What honors await not that man who may yet
+  direct its mighty power to plough, to sow, to harrow, and to reap!"
+  The progress of the steam-engine during those forty years does not
+  to-day appear so astounding. The sentiment here expressed has lost
+  none of its truth, nevertheless.
+
+In the year 1827, Perkins had attained working pressures, in a
+single-acting, single-cylinder engine, of upward of 800 pounds per
+square inch. At pressures exceeding 200 pounds, he had much trouble in
+securing effective lubrication, as all oils charred and decomposed at
+the high temperatures then unavoidably encountered, and he finally
+succeeded in evading this seemingly insurmountable obstacle by using
+for rubbing parts a peculiar alloy which required no lubrication, and
+which became so beautifully polished, after some wear, that the
+friction was less than where lubricants were used. At these high
+pressures Perkins seems to have met with no other serious difficulty.
+He condensed the exhaust-steam and returned it to the boiler, but did
+not attempt to create a vacuum in his condenser, and therefore needed
+no air-pump. Steam was cut off at one-eighth stroke.
+
+In the same year, Perkins made a compound engine on the Woolf plan,
+and adopted a pressure of 1,400 pounds, expanding eight times. In
+still another engine, intended for a steam-vessel, Perkins adopted, or
+proposed to adopt, 2,000 pounds pressure, cutting off the admission at
+one-sixteenth, in single-acting engines of 6 inches diameter of
+cylinder and 20 inches stroke of piston. The steam did not retain
+boiler-pressure at the cylinder, and this engine was only rated at 30
+horse-power.[90]
+
+  [90] Galloway and Hebert, on the Steam-Engine. London, 1836.
+
+Stuart follows a description of Perkins's work in the improvement of
+the steam-engine and the introduction of steam-artillery by the
+remark:
+
+" ... No other mechanic of the day has done more to illustrate an
+obscure branch of philosophy by a series of difficult, dangerous,
+and expensive experiments; no one's labors have been more deserving
+of cheering encouragement, and no one has received less. Even in
+their present state, his experiments are opening new fields for
+philosophical research, and his mechanism bids fair to introduce
+a new style into the proportions, construction, and form, of
+steam-machinery."
+
+Perkins's experience was no exception to the general rule, which
+denies to nearly all inventors a fair return for the benefits which
+they confer upon mankind.
+
+Another engineer, a few years later, was also successful in
+controlling and working steam under much higher pressures than are
+even now in use. This was Dr. Ernst Alban, a distinguished German
+engine-builder, of Plau, Mecklenburg, and an admirer of Oliver Evans,
+in whose path he, a generation later, advanced far beyond that great
+pioneer. Writing in 1843, he describes a system of engine and boiler
+construction, with which he used steam under pressures about equal to
+those experimentally worked by Jacob Perkins, Evans's American
+successor. Alban's treatise was translated and printed in Great
+Britain,[91] four years later.
+
+  [91] "The High-Pressure Steam-Engine," etc. By Dr. Ernst Alban.
+  Translated by William Pole, F. R. A. S. London, 1847.
+
+Alban, on one occasion, used steam of 1,000 pounds pressure. His
+boilers were similar in general form to the boiler patented by Stevens
+in 1805, but the tubes were horizontal instead of vertical. He
+evaporated from 8 to 10 pounds of water into steam of 600 to 800
+pounds pressure with each pound of coal. He states that the
+difficulty met by Perkins--the decomposition of lubricants in the
+steam-cylinder--did not present itself in his experiments, even when
+working steam at a pressure of 600 pounds on the square inch, and he
+found that less lubrication was needed at such high pressures than in
+ordinary practice. Alban expanded his steam about as much as Evans, in
+his usual practice, carrying a pressure of 150 pounds, and cutting off
+at one-third; he adopted greatly increased piston-speed, attaining 300
+feet per minute, at a time when common practice had only reached 200
+feet. He usually built an oscillating engine, and rarely attached a
+condenser. The valve was the locomotive-slide.[92] The stroke was made
+short to secure strength, compactness, cheapness, and high speed of
+rotation; but Alban does not seem to have understood the principles
+controlling the form and proportions of the expansive engine, or the
+necessity of adopting considerable expansion in order to secure
+economy in working steam of great tension, and therefore was,
+apparently, not aware of the advantages of a long stroke in reducing
+losses by "dead-space," in reducing risk of annoyance by hot journals,
+or in enabling high piston-speeds to be adopted. He seems never to
+have attained a sufficiently high speed of piston to become aware that
+the oscillating cylinder cannot be used at speeds perfectly
+practicable with the fixed cylinder.
+
+  [92] Invented by Joseph Maudsley, of London, 1827.
+
+Alban states that one of his smallest engines, having a cylinder 4-1/2
+inches in diameter and 1 foot stroke of piston, with a piston-speed of
+but 140 to 160 feet per minute, developed 4 horse-power, with a
+consumption of 5.3 pounds of coal per hour. This is a good result for
+so small an amount of work, and for an engine working at so low a
+speed of piston. An engine of 30 horse-power, also working very
+slowly, required but 4.1 pounds of coal per hour per horse-power.
+
+The work of Perkins and of Alban, like that of their predecessors,
+Evans, Stevens, and Trevithick, was, however, the work of engineers
+who were far ahead of their time. The general practice, up to the time
+which marked the beginning of the modern "period of refinement," had
+been but gradually approximating that just described. Higher pressures
+were slowly approached; higher piston-speeds came slowly into use;
+greater expansion was gradually adopted; the causes of losses of heat
+were finally discovered, and steam-jacketing and external
+non-conducting coverings were more and more generally applied as
+builders became more familiar with their work. The "compound engine"
+was now and then adopted; and each experiment, made with higher steam
+and greater expansion, was more nearly successful than the last.
+
+Finally, all these methods of securing economy became recognized, and
+the reasons for their adoption became known. It then remained, as the
+final step in this progression, to combine all these requisites of
+economical working in a double-cylinder engine, steam-jacketed, well
+protected by non-conducting coverings, working steam of high pressure,
+and with considerable expansion at high piston-speed. This is now done
+by the best builders.
+
+One of the best examples of this type of engine is that constructed by
+the sons of Jacob Perkins, who continued the work of their father
+after his death. Their engines are single-acting, and the small or
+high-pressure cylinder is placed on the top of the larger or
+low-pressure cylinder. The valves are worked by rotating stems, and
+the loss of heat and burning of packing incident to the use of the
+common method are thus avoided. The stuffing-boxes are placed at the
+end of long sleeves, closely surrounding the vertical valve-stems
+also, and the water of condensation which collects in these sleeves is
+an additional and thorough protection against excessively high
+temperature at the packing. The piston-rings are made of the alloy
+which has been found to require no lubrication.
+
+Steam is usually worked at from 250 to 450 pounds, and is generated in
+boilers composed of small tubes three inches in diameter and
+three-eighths of an inch thick, which are tested under a pressure of
+2,500 pounds per square inch. The safety-valve is usually loaded to
+400 pounds. The boiler is fed with distilled water, obtained
+principally by condensation of the exhaust-steam, any deficiency being
+made up by the addition of water from a distilling apparatus. Under
+these conditions, but 1-1/4 pound of coal is consumed per hour and per
+horse-power.
+
+THE PUMPING-ENGINE in use at the present time has passed through a
+series of changes not differing much from that which has been traced
+with the stationary mill-engine. The Cornish engine is still used to
+some extent for supplying water to towns, and is retained at deep
+mines. The modern Cornish engine differs very little from that of the
+time of Watt, except in the proportions of parts and the form of its
+details. Steam-pressures are carried which were never reached during
+the preceding period, and, by careful adjustment of well-set and
+well-proportioned valves and gearing, the engine has been made to work
+rather more rapidly, and to do considerably more work. It still
+remains, however, a large, costly, and awkward contrivance, requiring
+expensive foundations, and demanding exceptional care, skill, and
+experience in management. It is gradually going out of use. This
+engine, as now constructed by good builders, is shown in section in
+Fig. 101.
+
+A comparison with the Watt engine of a century earlier will at once
+enable any one to appreciate the extent to which changes may be made
+in perfecting a machine, even after it has become complete, so far as
+supplying it with all essential parts can complete it.
+
+[Illustration: FIG. 101.--Cornish Pumping-Engine, 1880.]
+
+In the figure, _A_ is the cylinder, taking steam from the boiler
+through the steam-passage, _M_. The steam is first admitted above the
+piston, _B_, driving it rapidly downward and raising the pump-rod,
+_E_. At an early period in the stroke the admission of steam is
+checked by the sudden closing of the induction-valve at _M_, and the
+stroke is completed under the action of expanding steam assisted by
+the inertia of the heavy parts already in motion. The necessary weight
+and inertia is afforded, in many cases, where the engine is applied to
+the pumping of deep mines, by the immensely long and heavy pump-rods.
+Where this weight is too great, it is counterbalanced, and where too
+small, weights are added. When the stroke is completed, the
+"equilibrium valve" is opened, and the steam passes from above to the
+space below the piston, and an equilibrium of pressure being thus
+produced, the pump-rods descend, forcing the water from the pumps and
+raising the steam-piston. The absence of the crank, or other device
+which might determine absolutely the length of stroke, compels a very
+careful adjustment of steam-admission to the amount of load. Should
+the stroke be allowed to exceed the proper length, and should danger
+thus arise of the piston striking the cylinder-head, _N_, the movement
+is checked by buffer-beams. The valve-motion is actuated by a
+plug-rod, _J K_, as in Watt's engine. The regulation is effected by a
+"cataract," a kind of hydraulic governor, consisting of a
+plunger-pump, with a reservoir attached. The plunger is raised by the
+engine, and then automatically detached. It falls with greater or less
+rapidity, its velocity being determined by the size of the
+eduction-orifice, which is adjustable by hand. When the plunger
+reaches the bottom of the pump-barrel, it disengages a catch, a weight
+is allowed to act upon the steam-valve, opening it, and the engine is
+caused to make a stroke. When the outlet of the cataract is nearly
+closed, the engine stands still a considerable time while the plunger
+is descending, and the strokes succeed each other at long intervals.
+When the opening is greater, the cataract acts more rapidly, and the
+engine works faster. This has been regarded until recently as the most
+economical of pumping-engines, and it is still generally used in
+freeing mines of water, and in situations where existing heavy
+pump-rods may be utilized in counterbalancing the steam-pressure, and,
+by their inertia, in continuing the motion after the steam, by its
+expansion, has become greatly reduced in pressure.
+
+In this engine a gracefully-shaped and strong beam, _D_, has taken
+the place of the ruder beam of the earlier period, and is carried on a
+well-built wall of masonry, _R_. _F_ is the exhaust-valve, by which
+the steam passes to the condenser, _G_, beside which is the air-pump,
+_H_, and the hot-well, _I_. The cylinder is steam-jacketed, _P_, and
+protected against losses of heat by radiation by a brick wall, _O_,
+the whole resting on a heavy foundation, _Q_.
+
+The Bull Cornish engine is also still not infrequently seen in use.
+The Cornish engine of Great Britain averages a duty of about
+45,000,000 pounds raised one foot high per 100 pounds of coal. More
+than double this economy has sometimes been attained.
+
+[Illustration: FIG. 102.--Steam-Pump.]
+
+A vastly simpler form of pumping-engine without fly-wheel is the now
+common "direct-acting steam-pump." This engine is generally made use
+of in feeding steam-boilers, as a forcing and fire pump, and wherever
+the amount of water to be moved is not large, and where the pressure
+is comparatively great. The steam-cylinder, _A R_, and feed-pump, _B
+Q_ (Fig. 102), are in line, and the two pistons have usually one rod,
+_D_, in common. The two cylinders are connected by a strong frame,
+_N_, and two standards fitted with lugs carry the whole, and serve as
+a means of bolting the pump to the floor or to its foundation.
+
+The method of working the steam-valve of the modern steam-pump is
+ingenious and peculiar. As shown, the pistons are moving toward the
+left; when they reach the end of their stroke, the face of the piston
+strikes a pin or other contrivance, and thus moves a small auxiliary
+valve, _I_, which opens a port, _E_, and causes steam to be admitted
+behind a piston, or permits steam to be exhausted, as in the figure,
+from before the auxiliary piston, _F_, and the pressure within the
+main steam-chest then forces that piston over, moving the main
+steam-valve, _G_, to which it is attached, admitting steam to the
+left-hand side of the main piston, and exhausting on the right-hand
+side, _A_. Thus the motion of the engine operates its own valves in
+such a manner that it is never liable to stop working at the end of
+the stroke, notwithstanding the absence of the crank and fly-wheel, or
+of independent mechanism, like the cataract of the Cornish engine.
+There is a very considerable variety of pumps of this class, all
+differing in detail, but all presenting the distinguishing feature of
+auxiliary valve and piston, and a connection by which it and the main
+engine each works the valve of the other combination.
+
+[Illustration: FIG. 103.--The Worthington Pumping-Engine, 1876.
+Section.]
+
+[Illustration: FIG. 104.--The Worthington Pumping-Engine.]
+
+In some cases these pumps are made of considerable size, and are
+applied to the elevation of water in situations to which the Cornish
+engine was formerly considered exclusively applicable. The
+accompanying figure illustrates such a pumping-engine, as built for
+supplying cities with water. This is a "compound" direct-acting
+pumping-engine. The cylinders, _A B_, are placed in line, working one
+pump, _F_, and operating their own air-pumps, _D D_, by a bell-crank
+lever, _L H_, connected to the pump-buckets by links, _I K_. Steam
+exhausted from the small cylinder, _A_, is further expanded in the
+large cylinder, _B_, and thence goes to the condenser, _C_. The
+valves, _N M_, are moved by the valve-gear, _L_, which is actuated by
+the piston-rod of a similar pair of cylinders placed by the side of
+the first. These valves are balanced, and the balance-plates, _R Q_,
+are suspended from the rods, _O P_, which allow them to move with the
+valves. By connecting the valves of each engine with the piston-rod
+of the other, it is seen that the two engines must work alternately,
+the one making a stroke while the other is still, and then itself
+stopping a moment while the latter makes its stroke.
+
+Water enters the pump through the induction-pipe, _E_, passes into the
+pump-barrel through the valves, _V V_, and issues through the
+eduction-valves, _T T_, and goes on to the "mains" by the pipe, _G_,
+above which is seen an air-chamber, which assists to preserve a
+uniform pressure on that side the pump. This engine works very
+smoothly and quietly, is cheap and durable, and has done excellent
+duty.
+
+Beam pumping-engines are now almost invariably built with crank and
+fly-wheel, and very frequently are compound engines. The accompanying
+illustration represents an engine of the latter form.
+
+[Illustration: FIG. 105.--Double-Cylinder Pumping-Engine, 1878.]
+
+[Illustration: FIG. 106.--The Lawrence Water-Works Engine.]
+
+_A_ and _B_ are the two steam-cylinders, connected by links and
+parallel motion, _C D_, to the great cast-iron beam, _E F_. At the
+opposite end of the beam, the connecting-rod, _G_, turns a crank,
+_H_, and fly-wheel, _L M_, which regulates the motion of the engine
+and controls the length of stroke, averting all danger of accident
+occurring in consequence of the piston striking either cylinder-head.
+The beam is carried on handsomely-shaped iron columns, which, with
+cylinders, pump, and fly-wheel, are supported by a substantial stone
+foundation. The pump-rod, _I_, works a double-acting pump, _J_, and
+the resistance to the issuing water is rendered uniform by an
+air-chamber, _K_, within which the water rises and falls when
+pressures tend to vary greatly. A revolving shaft, _N_, driven from
+the fly-wheel shaft, carries cams, _O P_, which move the lifting-rods
+seen directly over them and the valves which they actuate. Between the
+steam-cylinders and the columns which carry the beams is a well, in
+which are placed the condenser and air-pump. Steam is carried at 60 or
+80 pounds pressure, and expanded from 6 to 10 times.
+
+[Illustration: FIG. 107.--The Leavitt Pumping-Engine.]
+
+A later form of double-cylinder beam pumping-engine is that invented
+and designed by E. D. Leavitt, Jr., for the Lawrence Water-Works, and
+shown in Figs. 106 and 107. The two cylinders are placed one on each
+side the centre of the beam, and are so inclined that they may be
+coupled to opposite ends of it, while their lower ends are placed
+close together. At their upper ends a valve is placed at each end of
+the connecting steam-pipe. At their lower ends a single valve serves
+as exhaust-valve to the high-pressure and as steam-valve to the
+low-pressure cylinder. The pistons move in opposite directions, and
+steam is exhausted from the high-pressure cylinder directly into the
+nearer end of the low-pressure cylinder. The pump, of the
+"Thames-Ditton" or "bucket-and-plunger" variety, takes a full supply
+of water on the down-stroke, and discharges half when rising and half
+when descending again. The duty of this engine is reported by a board
+of engineers as 103,923,215 foot-pounds for every 100 pounds of coal
+burned. The duty of a moderately good engine is usually considered to
+be from 60 to 70 millions. This engine has steam-cylinders of 17-1/2
+and 36 inches diameter respectively, with a stroke of 7 feet. The pump
+had a capacity of about 195 gallons, and delivered 96 per cent. Steam
+was carried at a pressure of 75 pounds above the atmosphere, and was
+expanded about 10 times. Plain horizontal tubular boilers were used,
+evaporating 8.58 pounds of water from 98° Fahr. per pound of coal.
+
+STEAM-BOILERS.--The steam supplied to the forms of stationary engine
+which have been described is generated in steam-boilers of exceedingly
+varied forms. The type used is determined by the extent to which their
+cost is increased in the endeavor to economize fuel by the pressure of
+steam carried, by the greater or less necessity of providing against
+risk of explosion, by the character of the feed-water to be used, by
+the facilities which may exist for keeping in good repair, and even by
+the character of the men in whose hands the apparatus is likely to be
+placed.
+
+As has been seen, the changes which have marked the growth and
+development of the steam-engine have been accompanied by equally
+marked changes in the forms of the steam-boiler. At first, the same
+vessel served the distinct purposes of steam-generator and
+steam-engine. Later, it became separated from the engine, and was then
+specially fitted to perform its own peculiar functions; and its form
+went through a series of modifications under the action of the causes
+already stated.
+
+When steam began to be usefully applied, and considerable pressures
+became necessary, the forms given to boilers were approximately
+spherical, ellipsoidal, or cylindrical. Thus the boilers of De Caus
+(1615) and of the Marquis of Worcester (1663) were spherical and
+cylindrical; those of Savery (1698) were ellipsoidal and cylindrical.
+After the invention of the steam-engine of Newcomen, the pressures
+adopted were again very low, and steam-boilers were given irregular
+forms until, at the beginning of the present century, they were again
+of necessity given stronger shapes. The material was at first
+frequently copper; it is now usually wrought-iron, and sometimes
+steel.
+
+The present forms of steam-boilers may be classified as plain, flue,
+and tubular boilers. The plain cylindrical or common cylinder boiler
+is the only representative of the first class in common use. It is
+perfectly cylindrical, with heads either flat or hemispherical. There
+is usually attached to the boiler a "steam-drum" (a small cylindrical
+vessel), from which the steam is taken by the steam-pipe. This
+enlargement of the steam-space permits the mist, held in suspension by
+the steam when it first rises from the surface of the water, to
+separate more or less completely before the steam is taken from the
+boiler.
+
+[Illustration: FIG. 108.--Babcock & Wilcox's Vertical Boiler.]
+
+Flue-boilers are frequently cylindrical, and contain one or more
+cylindrical flues, which pass through from end to end, beneath the
+water-line, conducting the furnace-gases, and affording a greater area
+of heating-surface than can be obtained in the plain boiler. They are
+usually from 30 to 48 inches in diameter, and one foot or less in
+length for each inch of diameter. Some are, however, made 100 feet and
+more in length. The boiler is made of iron 1/4 to 3/8 of an inch in
+thickness, with hemispherical or carefully stayed flat heads, and
+without flues. The whole is placed in a brickwork setting. These
+boilers are used where fuel is inexpensive, where the cost of
+repairing would be great, or where the feed-water is impure. A
+cylindrical boiler, having one flue traversing it longitudinally, is
+called a Cornish boiler, as it is generally supposed to have been
+first used in Cornwall. It was probably first invented by Oliver Evans
+in the United States, previous to 1786, at which time he had it in
+use. The flue has usually a diameter 0.5 or 0.6 the diameter of the
+boiler. A boiler containing two longitudinal flues is called the
+Lancashire boiler. This form was also introduced by Oliver Evans. The
+flues have one-third the diameter of the boiler. Several flues of
+smaller diameter are often used, and when a still greater proportional
+area of heating-surface is required, tubes of from 1-1/4 inch to 4 or
+5 inches in diameter are substituted for flues. The flues are usually
+constructed by riveting sheets together, as in making the shell or
+outer portion. They are sometimes welded by British manufacturers, but
+rarely if ever in the United States. Tubes are always "lap-welded" in
+the process of rolling them. Small tubes were first used in the United
+States, about 1785. In portable, locomotive, and marine steam-boilers,
+the fire must be built within the boiler itself, instead of (as in the
+above described stationary boilers) in a furnace of brickwork exterior
+to the boiler. The flame and gases from the furnace or fire-box in
+these kinds of boiler are never led through brick passages en route to
+the chimney, as often in the preceding case, but are invariably
+conducted through flues or tubes, or both, to the smoke-stack. These
+boilers are also sometimes used as stationary boilers. Fig. 108
+represents such a steam-boiler in section, as it is usually exhibited
+in working drawings. Provision is made to secure a good circulation of
+water in these boilers by means of the "baffle-plates," seen in the
+sketch, which compel the water to flow as indicated by the arrows.
+The tubes are frequently made of brass or of copper, to secure rapid
+transmission of heat to the water, and thus to permit the use of a
+smaller area of heating-surface and a smaller boiler. The steam-space
+is made as large as possible, to secure immunity from "priming" or the
+"entrainment" of water with the steam. This type of steam-boiler,
+invented by Nathan Read, of Salem, Mass., in 1791, and patented in
+April of that year, was the earliest of the tubular boilers. In the
+locomotive boiler (Fig. 109), as in the preceding, the characteristics
+are a fire-box at one end of the shell and a set of tubes through
+which the gases pass directly to the smoke-stack. Strength,
+compactness, great steaming capacity, fair economy, moderate cost, and
+convenience of combination with the running parts, are secured by the
+adoption of this form. It is frequently used also for portable and
+stationary engines. It was invented in France by M. Seguin, and in
+England by Booth, and used by George Stephenson at about the same
+time--1828 or 1829.
+
+[Illustration: FIG. 109.--Stationary "Locomotive" Boiler.]
+
+Since the efficiency of a steam-boiler depends upon the extent of
+effective heating-surface per unit of weight of fuel burned in any
+given time--or, ordinarily, upon the ratio of the areas of heating and
+grate surface--peculiar expedients are sometimes adopted, having for
+their object the increase of heating-surface, without change of form
+of boiler and without proportionate increase of cost.
+
+One of these methods is that of the use of Galloway conical tubes
+(Fig. 110). These are very largely used in Great Britain, but are
+seldom if ever seen in the United States. The Cornish boiler, to which
+they are usually applied, consists of a large cylindrical shell, 6
+feet or more in diameter, containing one tube of about one-half as
+great dimensions, or sometimes two of one-third the diameter of the
+shell each. Such boilers have a very small ratio of heating to grate
+surface, and their large tubes are peculiarly liable to collapse. To
+remove these objections, the Messrs. Galloway introduced stay-tubes
+into the flues, which tubes are conical in form, and are set in either
+a vertical or an inclined position, the larger end uppermost. The area
+of heating-surface is thus greatly increased, and, at the same time,
+the liability to collapse is reduced. The same results are obtained by
+another device of Galloway, which is sometimes combined with that just
+described in the same boiler. Several sheets in the flue have
+"pockets" worked into them, which pockets project into the
+flue-passage.
+
+[Illustration: FIG. 110.]
+
+Another device is that of an American engineer, Miller, who surrounds
+the furnace of cylindrical and other boilers with water-tubes. The
+"fuel-economizers" of Greene and others consist of similar collections
+of tubes set in the flues, between the boiler and the chimney.
+
+"_Sectional_" boilers are gradually coming into use with high
+pressures, on account of their greater safety against disastrous
+explosions. The earliest practicable example of a boiler of this class
+was probably that of Colonel John Stevens, of Hoboken, N. J. Dr.
+Alban, who, forty years later, attempted to bring this type into
+general use, and constructed a number of such boilers, did not
+succeed. Their introduction, like that of all radical changes in
+engineering, has been but slow, and it has been only recently that
+their manufacture has become an important branch of industry.
+
+A committee of the American Institute, of which the author was
+chairman, in 1871, examined several boilers of this and the ordinary
+type, and tested them very carefully. They reported that they felt
+"confident that the introduction of this class of steam-boilers will
+do much toward the removal of the cause of that universal feeling of
+distrust which renders the presence of a steam-boiler so objectionable
+in every locality. The difficulties in thoroughly inspecting these
+boilers, in regulating their action, and other faults of the class,
+are gradually being overcome, and the committee look forward with
+confidence to the time when their use will become general, to the
+exclusion of older and more dangerous forms of steam-boilers."
+
+The economical performance of these boilers with a similar ratio of
+heating to grate surface is equal to that of other kinds. In fact,
+they are usually given a somewhat higher ratio, and their economy of
+fuel frequently exceeds that of the other types. Their principal
+defect is their small capacity for steam and water, which makes it
+extremely difficult to obtain steady steam-pressure. Where they are
+employed, the feed and draught should be, if possible, controlled by
+automatic attachments, and the feed-water heated to the highest
+attainable temperature. Their satisfactory working depends, more than
+in other cases, on the ability of the fireman, and can only be secured
+by the exercise of both care and skill.
+
+Many forms of these boilers have been devised. Walter Hancock
+constructed boilers for his steam-carriage of flat plates connected by
+stay-bolts, several such sections composing the boiler; and about the
+same time (1828) Sir Goldsworthy Gurney constructed for a similar
+purpose boilers consisting of a steam and a water reservoir, placed
+one above the other, and connected by triangularly-bent water-tubes
+exposed to the heat of the furnace-gases. Jacob Perkins made many
+experiments looking to the employment of very high steam-pressures,
+and in 1831 patented a boiler of this class, in which the
+heating-surfaces nearest the fire were composed of iron tubes, which
+tubes also served as grate-bars. The steam and water space was
+principally comprised within a comparatively large chamber, of which
+the walls were secured by closely distributed stay-bolts. For
+extremely high pressures, boilers composed only of tubes were used.
+Dr. Ernst Alban described the boiler already referred to, and its
+construction and operation, and stated that he had experimented with
+pressures as high as 1,000 pounds to the square inch.
+
+The Harrison steam-boiler, which has been many years in use in the
+United States, consists of several sections, each of which is made up
+of hollow globes of cast-iron, communicating with each other by necks
+cast upon the spheres, and fitted together with faced joints. Long
+bolts, extending from end to end of each row, bind the spheres
+together. (_See_ Fig. 111.)
+
+[Illustration: FIG. 111.--Harrison's Sectional Boiler.]
+
+An example of another modern type in extensive use is given in Fig.
+112, a semi-sectional boiler, which consists of a series of inclined
+wrought-iron tubes, connected by T-heads, which form the vertical
+water-channels, at each end. The joints are faced by milling them, and
+then ground so perfectly tight that a pressure of 500 pounds to the
+square inch is insufficient to produce leakage. No packing is used.
+The fire is made under the front and higher end of the tubes, and the
+products of combustion pass up between the tubes into a
+combustion-chamber under the steam and water drum; hence they pass
+down between the tubes, then once more up through the space between
+the tubes, and off to the chimney. The steam is taken out at the top
+of the steam-drum near the back end of the boiler. The rapid
+circulation prevents to some extent the formation of deposits or
+incrustations upon the heating-surfaces, sweeping them away and
+depositing them in the mud-drum, whence they are blown out. Rapid
+circulation of water, as has been shown by Prof. Trowbridge, also
+assists in the extraction of the heat from the gases, by the
+presentation of fresh water continually, as well as by the prevention
+of incrustation.
+
+[Illustration: FIG. 112.--Babcock and Wilcox's Sectional Boiler.]
+
+Attempts have been made to adapt sectional boilers to marine engines;
+but very little progress has yet been made in their introduction. The
+Root sectional boiler (Fig. 113), an American design, which is in
+extensive use in the United States and Europe, has also been
+experimentally placed in service on shipboard. Its heating-surface
+consists wholly of tubes, which are connected by a peculiarly formed
+series of caps; the joints are made tight with rubber "grummets."
+
+[Illustration: FIG. 113.--Root Sectional Boiler.]
+
+
+SECTION II.--PORTABLE AND LOCOMOTIVE ENGINES.
+
+Engines and boilers, when of small size, are now often combined in one
+structure which may be readily transported. Where they have a common
+base-plate simply, as in Fig. 114, they are called, usually,
+"semi-portable engines." These little engines have some decided
+advantages. Being attached to one base, the combined engine and boiler
+is easily transported, occupies little space, and may very readily be
+mounted upon wheels, rendering it peculiarly well adapted for
+agricultural purposes.
+
+[Illustration: FIG. 114.--Semi-Portable Engine, 1878.]
+
+The example here shown differs in its design from those usually seen
+in the market. The engine is not fastened to or upon the boiler, and
+is therefore not affected by expansion, nor are the bearings
+overheated by conduction or by ascending heat from the boiler. The
+fly-wheel is at the base, which arrangement secures steadiness at the
+high speed which is a requisite for economy of fuel. The boilers are
+of the upright tubular style, with internal fire-box, and are
+intended to be worked at 150 pounds pressure per inch. They are fitted
+with a baffle-plate and circulating-pipe, to prevent priming, and also
+with a fusible plug, which will melt and prevent the crown-sheet of
+the boiler burning, if the water gets low.
+
+[Illustration: FIG. 115.--Semi-Portable Engine, 1878.]
+
+Another illustration of this form of engine, as built in small sizes,
+is seen below. The peculiarity of this engine is, that the cylinder is
+placed in the top of the boiler, which is upright. By this arrangement
+the engine is constantly drawing from the boiler the hottest and
+driest steam, and there is thus no liability of serious loss by
+condensation, which is rapid, even in a short pipe, when the engine is
+separate from the boiler.
+
+The engine illustrated is rated at 10 horse-power, and makers are
+always expected to guarantee their machines to work up to the rated
+power. The cylinder is 7 by 7 inches, and the main shaft is directly
+over it. On this shaft are three eccentrics, one working the pump, one
+moving the valves, and the third one operating the cut-off. The
+driving-pulley is 20 inches in diameter, and the balance-wheel 30
+inches. The boiler has 15 1-1/4-inch flues. It is furnished with a
+heater in its lower portion. The boiler of this engine is tested up to
+200 pounds, and is calculated to carry 100 pounds working pressure,
+though that is not necessary to develop the full power of the engine.
+The compactness of the whole machine is exceptional. It can be set up
+in a space 5 feet square and 8 feet high. The weight of the 10
+horse-power engine is 1,540 pounds, and of the whole machine 4,890
+pounds, boxed for shipment. Every part of the mechanism usually fits
+and works with the exactness of a gun-lock, as each piece is carefully
+made to gauge.
+
+Portable engines are those which are especially intended to be moved
+conveniently from place to place. The engine is usually attached to
+the boiler, and the feed-pump is generally attached to the engine. The
+whole machine is carried on wheels, and is moved from one place to
+another, usually by horses, but sometimes by its own engine, which is
+coupled by an engaging and disengaging apparatus to the rear-wheels.
+English builders have usually excelled in the construction of this
+class of steam-engine, although it is probable that the best American
+engines are fully equal to them in design, material, and construction.
+
+The later work of the best-known English builders has given economical
+results that have surprised engineers. The annual "shows" of the Royal
+Agricultural Society have elicited good evidence of skill in
+management as well as of excellence of design and construction. Some
+little portable engines have exhibited an economical efficiency
+superior to that of the largest marine engines of any but the compound
+type, and even closely competing with that form. The causes of this
+remarkable economy are readily learned by an inspection of these
+engines, and by observation of the method of managing them at the
+test-trial. The engines are usually very carefully designed. The
+cylinders are nicely proportioned to their work, and their pistons
+travel at high speed. Their valve-gear consists usually of a plain
+slide-valve, supplemented by a separate expansion-slide, driven by an
+independent eccentric, and capable of considerable variation
+in the point of cut-off. This form of expansion-gear is very
+effective--almost as much so as a drop cut-off--at the usual grade of
+expansion, which is not far from four times. The governor is usually
+attached to a throttle-valve in the steam-pipe, an arrangement which
+is not the best possible under variable loads, but which produces no
+serious loss of efficiency when the engine is driven, as at
+competitive trials, under the very uniform load of a Prony strap-brake
+and at very nearly the maximum capacity of the machine. The most
+successful engines have had steam-jacketed cylinders--always an
+essential to maximum economy--with high steam and a considerable
+expansion. The boilers are strongly made, and are, as are also all
+other heated surfaces, carefully clothed with non-conducting material,
+and well lagged over all. The details are carefully proportioned, the
+rods and frames are strong and well secured together, and the bearings
+have large rubbing-surfaces. The connecting-rods are long and
+easy-working, and every part is capable of doing its work without
+straining and with the least friction.
+
+In handling the engines at the competitive trial, most experienced and
+skillful drivers are selected. The difference between the performances
+of the same engine in different hands has been found to amount to from
+10 to 15 per cent., even where the competitors were both considered
+exceptionally skillful men. In manipulating the engine, the fires are
+attended to with the utmost care; coal is thrown upon them at regular
+and frequent intervals, and a uniform depth of fuel and a perfectly
+clean fire are secured. The sides and corners of the fire are looked
+after with especial care. The fire-doors are kept open the least
+possible time; not a square inch of grate-surface is left unutilized,
+and every pound of coal gives out its maximum of calorific power, and
+in precisely the place where it is needed. Feed-water is supplied as
+nearly as possible continuously, and with the utmost regularity. In
+some cases the engine-driver stands by his engine constantly, feeding
+the fire with coal in handfuls, and supplying the water to the heater
+by hand by means of a cup. Heaters are invariably used in such cases.
+The exhaust is contracted no more than is absolutely necessary for
+draught. The brake is watched carefully, lest irregularity of
+lubrication should cause oscillation of speed with the changing
+resistance. The load is made the maximum which the engine is designed
+to drive with economy. Thus all conditions are made as favorable as
+possible to economy, and they are preserved as invariable as the
+utmost care on the part of the attendant can make them.
+
+These trials are usually of only three or five hours' duration, and
+thus terminate before it becomes necessary to clean fires. The
+following are results obtained at the trial of engines which took
+place in July, 1870, at the Oxford Agricultural Fair:
+
+  KEY:
+  A: Number.
+  B: Diameter.
+  C: Stroke.
+  D: Nominal.
+  E: Dynamometric.
+  F: Point of cut off.
+  G: Revolutions per minute.
+  H: Pounds coal per horse-power per hour.
+
+  ---------------+-------------+-----+--------------+------+------+----
+  MAKERS' NAME   | CYLINDERS.  |     | HORSE-POWER. |      |      |
+      AND        +-----+-------+     +-------+------+      |      |
+   RESIDENCE.    |  A  |   B   |  C  |   D   |  E   |  F   |  G   |  H
+  ---------------+-----+-------+-----+-------+------+------+------+----
+                 |     |Inches.| In. |       |      |      |      |
+  Clayton,       |     |       |     |       |      |      |      |
+  Shuttleworth   |  1  | 7     |  12 |   4   | 4.42 |  ... |121.65|3.73
+  & Co., Lincoln |     |       |     |       |      |      |      |
+                 |     |       |     |       |      |      |      |
+  Brown & May,   |     |       |     |       |      |      |      |
+  Devizes        |  1  | 7-3/16|  12 |   4   | 4.19 | 11.48|125.65|4.44
+                 |     |       |     |       |      |      |      |
+  Reading Iron-  |     |       |     |       |      |      |      |
+  Works Company, |  1  | 5-3/4 |  14 |   4   | 4.16 |  ... |145.7 |4.65
+  Reading        |     |       |     |       |      |      |      |
+  ---------------+-----+-------+-----+-------+------+------+------+----
+
+These were horizontal engines, attached to locomotive boilers.
+
+At a similar exhibition held at Bury, in 1867, considerably better
+results even than these were reported, as below, from engines of
+similar size and styles:
+
+  KEY:
+  A: Number.
+  B: Diameter.
+  C: Stroke.
+  D: Nominal.
+  E: Dynamometric.
+  F: Point of cut off.
+  G: Revolutions per minute.
+  H: Pounds coal per horse-power per hour.
+
+  ---------------+-------------+-----+--------------+------+------+----
+  MAKERS' NAME   | CYLINDERS.  |     | HORSE-POWER. |      |      |
+      AND        +-----+-------+     +-------+------+      |      |
+   RESIDENCE.    |  A  |   B   |  C  |   D   |  E   |  F   |  G   |  H
+  ---------------+-----+-------+-----+-------+------+------+------+----
+                 |     |Inches.| In. |       |      |      |      |
+  Clayton,       |     |       |     |       |      |      |      |
+  Shuttleworth   |  1  |10     | 20  |   10  | 11.00| 3.10 | 71.5 | 4.13
+  & Co., Lincoln |     |       |     |       |      |      |      |
+                 |     |       |     |       |      |      |      |
+  Reading Iron-  |     |       |     |       |      |      |      |
+  Works Company, |  1  | 8-5/8 | 20  |   10  | 10.43| 1.4  |109.4 | 4.22
+  Reading        |     |       |     |       |      |      |      |
+  ---------------+-----+-------+-----+-------+------+------+------+----
+
+With all these engines steam-jackets were used; the feed-water was
+highly and uniformly heated by exhaust-steam; the coal was selected,
+finely broken, and thrown on the fire with the greatest care; the
+velocity of the engines, the steam-pressure, and the amount of
+feed-water, were very carefully regulated, and all bearings were run
+quite loose; the engine-drivers were usually expert "jockeys."
+
+The next illustration represents the portable steam-engine as built by
+one of the oldest and most experienced manufacturers of such engines
+in the United States.
+
+In the boilers of these engines the heating-surface is given less
+extent than in the stationary engine-boiler, but much greater than in
+the locomotive, and varies from 10 to 20 square feet per horse-power.
+The boilers are made very strong, to enable them to withstand the
+strains due to the attached engine, which are estimated as equivalent
+to from one-tenth to one-fifth that due to the steam-pressure. The
+boiler is sometimes given even double the strength usual with
+stationary boilers of similar capacity. The engine is mounted, in this
+example, directly over the boiler, and all parts are in sight and
+readily accessible to the engineer.
+
+[Illustration: FIG. 116.--The Portable Steam-Engine, 1878.]
+
+One of these engines, of 20 horse-power, has a steam-cylinder 10
+inches in diameter and 18 inches stroke of piston, making 125
+revolutions per minute, and has 9 square feet of grate-surface and 288
+feet of heating-surface. It weighs about 4-1/2 tons. Steam is carried
+at 125 pounds.
+
+In the class of engines just described, the draught is obtained by the
+blast of the exhaust-steam which is led into the chimney. Such engines
+are now sold at from $120 to $150 per horse-power, according to size
+and quality, the smaller engines costing most. The usual consumption
+of fuel is from 4 to 6 pounds per hour and per horse-power, burning
+from 15 to 20 pounds on each square foot of grate, and each pound
+evaporating about 8 pounds of water. A usual weight is, for the larger
+sizes, 500 pounds per horse-power.
+
+[Illustration: FIG. 117.--The Thrashers' Road-Engine, 1878.]
+
+These engines are sometimes arranged to propel themselves, as in the
+Mills "Thrashers'" road-engine or locomotive, of which the
+accompanying engraving is a good representation. This engine is
+proportioned for hauling a tank containing 10 barrels, or more, of
+water and a grain-separator over all ordinary roads, and to drive a
+thrashing-machine or saw-mill, developing 20 or 25 horse-power. This
+example of the road-engine has a boiler built to work at 250 pounds of
+steam; the engine is designed for a maximum power of 30 horses.
+
+This engine has a balanced valve and automatic cut-off, and is fitted
+with a reversing-gear for use on the road. The driving-wheels are of
+wrought-iron, 56 inches diameter and 8 inches wide, with cast-iron
+driving-arms. Both wheels are drivers on curves as well as on straight
+lines. The engine is guided and fired by one man, and the total weight
+is so small that it will pass safely over any good country bridge. A
+brake is attached, to insure safety when going down-hill. Although
+designed to move at a speed of about three miles per hour, the
+velocity of the piston may be increased so that four miles per hour
+may be accomplished when necessary.
+
+[Illustration: FIG. 118.--Fisher's Steam-Carriage.]
+
+This is an excellent example of this kind of engine as constructed at
+the present time. The strongly-built boiler, with its heater, the
+jacketed cylinder, and light, strong frame of the engine, the steel
+running-gear, the carefully-covered surfaces of cylinder and boiler,
+and excellent proportions of details, are illustrations of good modern
+engineering, and are in curious contrast with the first of the class,
+built a century earlier by Smeaton.
+
+Steam-carriages for passengers are now rarely built. Fig. 118
+represents that designed by Fisher about 1870 or earlier. It was only
+worked experimentally.
+
+[Illustration: FIG. 119.--Road and Farm Locomotive.]
+
+The above is an engraving of a road and farm locomotive as built by
+one of the most successful among several British firms engaged in this
+work.
+
+The capacity of these engines has been determined by experiment by the
+author in the United States, and abroad by several distinguished
+engineers.
+
+The author made a trial of one of these engines at South Orange, N.
+J., to determine its power, speed, and convenience of working and
+man[oe]uvring. The following were the principal dimensions:
+
+  Weight of engine, complete, 5 tons 4 cwt.          11,648 pounds.
+  Steam-cylinder--diameter                                7-3/4 inches.
+  Stroke of piston                                       10 inches.
+  Revolution of crank to one of driving-wheels           17
+  Driving-wheels--diameter                               60 inches.
+      "           breadth of tire                        10 inches.
+      "           weight, each                          450 pounds.
+  Boiler--length over all                                 8 feet.
+    "     diameter of shell                              30 feet.
+    "     thickness of shell                           7/16 inch.
+    "     fire-box sheets, outside, thickness           1/2 inch.
+  Load on driving-wheels, 4 tons 10 cwt.             10,080 pounds.
+
+The boiler was of the ordinary locomotive type, and the engine was
+mounted upon it, as is usual with portable engines.
+
+The steam-cylinder was steam-jacketed, in accordance with the most
+advanced practice here and abroad. The crank-shaft and other
+wrought-iron parts subjected to heavy strains were strong and plainly
+finished. The gearing was of malleableized cast-iron, and all
+bearings, from crank-shaft to driving-wheel, on each side, were
+carried by a single sheet of half-inch plate, which also formed the
+sides of the fire-box exterior.
+
+The following is a summary of the conclusions deduced by the author
+from the trial, and published in the _Journal of the Franklin
+Institute_: A traction-engine may be so constructed as to be easily
+and rapidly man[oe]uvred on the common road; and an engine weighing
+over 5 tons may be turned continuously without difficulty on a circle
+of 18 feet radius, or even on a road but little wider than the length
+of the engine. A locomotive of 5 tons 4 hundredweight has been
+constructed, capable of drawing on a good road 23,000 pounds up a
+grade of 533 feet to the mile, at the rate of four miles an hour; and
+one might be constructed to draw more than 63,000 pounds up a grade of
+225 feet to the mile, at the rate of two miles an hour.
+
+It was further shown that the coefficient of traction with
+heavily-laden wagons on a good macadamized road is not far from .04;
+the traction-power of this engine is equal to that of 20 horses; the
+weight, exclusive of the weight of the engine, that could be drawn on
+a level road, was 163,452 pounds; and the amount of fuel required is
+estimated at 500 pounds a day. The advantages claimed for the
+traction-engine over horse-power are: no necessity for a limitation of
+working-hours; a difference in first cost in favor of steam; and in
+heavy work on a common road the expense by steam is less than 25 per
+cent. of the average cost of horse-power, a traction-engine capable of
+doing the work of 25 horses being worked at as little expense as 6 or
+8 horses. The cost of hauling heavy loads has been estimated at 7
+cents per ton per mile.
+
+Such engines are gradually becoming useful in steam-ploughing. Two
+systems are adopted. In the one the engine is stationary, and hauls a
+"gang" of ploughs by means of a windlass and wire rope; in the other
+the engine traverses a field, drawing behind it a plough or a gang of
+ploughs. The latter method has been proposed for breaking up
+prairie-land.
+
+Thus, thirty years after the defeat of the intelligent, courageous,
+and persistent Hancock and his coworkers in the scheme of applying the
+steam-engine usefully on the common road, we find strong indications
+that, in a new form, the problem has been again attacked, and at least
+partially solved.
+
+One of the most important of the prerequisites to ultimate success in
+the substitution of steam for animal power on the highway is that our
+roads shall be well made. As the greatest care and judgment are
+exercised, and an immense outlay of capital is considered justifiable,
+in securing easy grades and a smooth track on our railroad routes, we
+may readily believe that similar precaution and outlay will be found
+advisable in adapting the common road to the road-locomotive. It would
+seem to the engineer that the natural obstacles generally supposed to
+stand in the way have, after all, no real existence. The principal
+inconvenience that may be anticipated will probably arise from the
+carelessness or avarice of proprietors, which may sometimes cause them
+to appoint ignorant and inefficient engine-drivers, giving them charge
+of what are always excellent servants, but terrible masters.
+Nevertheless, as the transportation of passengers on railroads is
+found to be attended with less liability to loss of life or injury of
+person than their carriage by stage-coach, it will be found, very
+probably, that the general use of steam in transporting freight on
+common roads may be attended with less risk to life or property than
+to-day attends the use of horse-power.
+
+The STEAM FIRE-ENGINE is still another form of portable engine. It is
+also one of the latest of all applications of steam-power. The steam
+fire-engine is peculiarly an American production. Although previously
+attempted, their permanently successful introduction has only occurred
+within the last fifteen years.
+
+[Illustration: FIG. 120.--The Latta Steam Fire-Engine.]
+
+As early as 1830, Braithwaite and Ericsson, of London, England, built
+an engine with steam and pump cylinders of 7 and 6-1/2 inches
+diameter, respectively, with 16 inches stroke of piston. This machine
+weighed 2-1/2 tons, and is said to have thrown 150 gallons of water
+per minute to a height of between 80 and 100 feet. It was ready for
+work in about 20 minutes after lighting the fire. Braithwaite
+afterward supplied a more powerful engine to the King of Prussia, in
+1832. The first attempt made in the United States to construct a steam
+fire-engine was probably that of Hodge, who built one in New York in
+1841. It was a strong and very effective machine, but was far too
+heavy for rapid transportation. The late J. K. Fisher, who throughout
+his life persistently urged the use of steam-carriages and
+traction-engines, designing and building several, also planned a
+steam fire-engine. Two were built from his design by the Novelty
+Works, New York, about 1860, for Messrs. Lee & Larned. They were
+"self-propellers," and one of them, built for the city of
+Philadelphia, was sent to that city over the highway, driven by its
+own engines. The other was built for and used by the New York Fire
+Department, and did good service for several years. These engines were
+heavy, but very powerful, and were found to move at good speed under
+steam and to man[oe]uvre well. The Messrs. Latta, of Cincinnati, soon
+after succeeded in constructing comparatively light and very effective
+engines, and the fire department of that city was the first to adopt
+steam fire-engines definitely as their principal reliance. This change
+has now become general.
+
+The steam fire-engine has now entirely displaced the old hand-engine
+in all large cities. It does its work at a fraction of the cost of the
+latter. It can force its water to a height of 225 feet, and to a
+distance of more than 300 feet horizontally, while the hand-engine can
+seldom throw it one-third these distances; and the "steamer" may be
+relied upon to work at full power many hours if necessary, while the
+men at the hand-engine soon become fatigued, and require frequent
+relief. The city of New York has 40 steam fire-engines. One engine to
+every 10,000 inhabitants is a proper proportion.
+
+In the standard steam fire-engine (Fig. 120) reciprocating engines and
+pumps are adopted, as seen in section in Fig. 121, in which _A_ is the
+furnace, and _B_ the set of closely-set vertical fire-tubes in the
+boiler. _C_ is the combustion-chamber, _D_ the smoke-pipe, and _R_ the
+steam-space. _E_ is the steam-cylinder, and _F_ the pump, which is
+seen to be double-acting. There are two pairs of engines and pumps,
+working on cranks, set at right angles, and turning a balance-wheel
+seen behind them. _G_ is the feed-pump which supplies water to the
+boiler, _H_ the air-chamber which equalizes the water-pressure, which
+reaches it through the pipe, _I J_. _K_ is the feed-water tank, under
+the driver's seat, _L_, which, with the engines and boiler, are
+carried on the frame, _M M_. The fireman stands on the platform, _N_.
+When it is necessary to move the machine, an endless chain connects
+the crank-shaft with the rear-wheels, and the engine, with pumps shut
+off, is thus made to drive the wheels at any desired speed.
+
+[Illustration: FIG. 121.--The Amoskeag Engine. Section.]
+
+[Illustration: FIG. 122.--The Silsby Rotary Steam Fire-Engine.]
+
+A self-propelling engine by the Amoskeag Company had the following
+dimensions and performance: Weight, 4 tons; speed, 8 miles per hour;
+steam-pressure, 75 pounds per square inch; height of stream from
+1-1/4-inch nozzle, 225 feet; 1-3/4-inch nozzle, 150 feet; distance
+horizontally, 1-1/4-inch nozzle, 300 feet; 1-3/4-inch, 250 feet--a
+performance which contrasts wonderfully with that of the hand-worked
+fire-engine which these engines have now superseded.
+
+It has recently become common to construct the steam fire-engine with
+rotary engine and pump (Fig. 122). The superiority of a rotary motion
+for a steam-engine is apparently so evident that many attempts have
+been made to overcome the practical difficulties to which it is
+subject. One of these difficulties, and the principal one, has been
+the packing of the part which performs the office of the piston in the
+straight cylinder. Robert Stephenson once expressed the opinion that a
+rotary engine would never be made to work successfully, on account of
+this difficulty of packing. The most palpable of the advantages of the
+rotary engine are the reduction in the size of the engine, claimed to
+result from the great velocity of the piston; the avoidance of great
+accidental strains, especially noticed in propelling ships; and a
+great saving of the power which is asserted to be expended in the
+reciprocating engine in overcoming the inertia while changing the
+direction of the motions. These advantages adapt the rotary engine, in
+an especial manner, to the driving of a locomotive or steam
+fire-engine.
+
+[Illustration: FIG. 123.--Rotary Steam-Engine.]
+
+[Illustration: FIG. 124.--Rotary Pump.]
+
+In the Holly rotary engine, seen in Fig. 123, eccentrics and
+sliding-cams, which are frequently used in rotary engines, and which
+are objectionable on account of their great friction, are avoided.
+Corrugated pistons, or irregular cams, _C D_, are adopted, forming
+chambers within the cases. In the engine the steam enters at _A_, at
+the bottom of the case, and presses the cams apart. The only packing
+used is in the ends of the long metal cogs, which are ground to fit
+the case and are kept out by the momentum of the cams, assisted by a
+slight spring back of the packing-pieces. The friction on the pump
+(Fig. 124) is said to be less than in the engine. This is the reason
+given in support of the claim that the rotary engine forces water to a
+given distance with from one-fourth to one-third the steam-pressure
+necessary to drive all reciprocating engines. The smaller amount of
+power necessary to do the work, the less strain and consequent wear
+and tear upon the whole machine, are said to make it more durable and
+reliable. The pump being chambered, its liability to injury by the use
+of dirty or gritty water is lessened, and it is stated that it will
+last for years, pumping gritty water that would soon cut out a
+piston-pump. The pump used with this engine is, as shown in the above
+illustration, somewhat similar to the rotary engine driving it. Each
+of the revolving pistons has three long teeth bearing against the
+cylinder, and packed, to prevent leakage, like the engine-cams. They
+are carried on steel shafts coupled to the engine-shafts. The water
+enters at _E_ and is discharged at _F_, and the passages are purposely
+made large in order that sand, chips, and dirt, which may enter with
+the water, may pass through.
+
+The rotary engine is gradually coming into use for various special
+purposes, where small power is called for, and where economy of fuel
+is not important; but it has never yet competed, and may perhaps never
+in the future compete, with the reciprocating-piston engine where
+large engines are required, or where even moderate economy of fuel is
+essential. This form of engine has assumed so little importance, in
+fact, in the application of the steam-engine, that comparatively
+little is known of its history. Watt invented a rotary engine, and
+Yule many years afterward (1836) constructed such engines at Glasgow.
+Lamb patented another in 1842, Behrens still another in 1847. Napier,
+Hall, Massey, Holly, La France, and others, have built engines of this
+class in later times. Nearly all consist either of cams rotating in
+gear, as in those above sketched, or of a piston set radially in a
+cylinder of small diameter, which turns on its axis within a much
+larger cylinder set eccentrically, the piston, as the former turns,
+sliding in and out of the smaller cylinder as its outer edge slides in
+contact with the inner surface of the larger. In some forms of rotary
+engine, a piston revolves on a central shaft, and a sliding abutment
+in the external cylinder serves to separate the steam from the exhaust
+side and to confine the steam expanding while doing work. Nearly all
+of these combinations are also used as pumps.
+
+Fire-engines, made by the best-known American builders of engines,
+with reciprocating engines and pumps, such as are in general use in
+the United States, have become standard in general plan and
+arrangement of details. These are probably the best illustrations of
+extreme lightness, combined with strength of parts and working power,
+which have ever been produced in any branch of mechanical
+engineering. By using a small boiler crowded with heating-surface,
+very carefully proportioned and arranged, and with small water-spaces;
+by adopting steel for running-gear and working parts wherever
+possible; by working at high piston-speed and with high
+steam-pressure; by selecting fuel with extreme care--by all these
+expedients, the steam fire-engine has been brought, in this country,
+to a state of efficiency far superior to anything seen elsewhere.
+Steam is raised with wonderful promptness, even from cold water, and
+water is thrown from the nozzle at the end of long lines of hose to
+great distances. But this combination of lightness with power is only
+attained at the expense of a certain regularity of action which can
+only be secured by greater water and steam capacity in the boiler. The
+small quantity of water contained within the boiler makes it necessary
+to give constant attention to the feed, and the tendency, almost
+invariably observed, to serious foaming and priming not only compels
+unintermitted care while running, but even introduces an element of
+danger which is not to be despised, even though the machine be in
+charge of the most experienced and skillful attendants. Even the
+greatest care, directed by the utmost skill, would not avail to
+prevent frequent explosions, were it not for the fact that it rarely,
+if ever, happens that accidents to such boilers occur from low water,
+unless the boiler is actually completely emptied of water. In driving
+them at fires, they frequently foam so violently that it is utterly
+impossible to obtain any clew to the amount of water present, and the
+attendant usually keeps his feed-pump on and allows the foaming to go
+on. As long as water is passing into the boiler it is very unlikely
+that any portion will become overheated and that accident will occur.
+Such management appears very reckless, and yet accident from such a
+cause is exceedingly rare.
+
+The changes which have been made in LOCOMOTIVE-CONSTRUCTION during the
+past few years have also been in the direction of the refinement of
+the earlier designs, and have been accompanied by corresponding
+changes in all branches of railroad-work. The adjustment of parts to
+each other and proportioning them to their work, the modification of
+the minor details to suit changes of general dimensions, the
+improvement of workmanship, and the use of better material, have
+signalized this latest period. Special forms of engine have been
+devised for special kinds of work. Small, light tank-engines (Fig.
+125), carrying their own fuel and water without "tenders," are used
+for moving cars about terminal stations and for making up trains;
+powerful, heavy, slow-moving engines, of large boiler-capacity and
+with small wheels, are used on steep gradients and for hauling long
+trains laden with coal and heavy merchandise; and hardly less powerful
+but quite differently proportioned "express"-engines are used for
+passenger and mail service.
+
+[Illustration: FIG. 125.--Tank-Engine, New York Elevated Railroad.]
+
+[Illustration: FIG. 126.--Forney's Tank-Locomotive.]
+
+A peculiar form of engine (Fig. 126) has been designed by Forney, in
+which the whole weight of engine, tender, coal, and water, is carried
+by one frame and on one set of wheels, the permanent weight falling on
+the driving-wheels and the variable load on the truck. These engines
+have also a comparatively short wheel-base and high pulling-power. The
+lightest tank-engines of the first class mentioned weigh 8 or 10 tons;
+but engines much lighter than these, even, are built for mines, where
+they are sent into the galleries to bring out the coal-laden wagons.
+The heaviest engines of this class attain weights of 20 or 30 tons.
+The heaviest engine yet constructed in the United States is said to be
+one in use on the Philadelphia & Reading Railroad, having a weight of
+about 100,000 pounds, which is carried on 12 driving-wheels.
+
+[Illustration: FIG. 127.--British Express Engine.]
+
+[Illustration: FIG. 128.--The Baldwin Locomotive. Section.]
+
+[Illustration: FIG. 129.--The American Type of Express-Engine, 1878.]
+
+A locomotive has two steam-cylinders, either side by side within the
+frame, and immediately beneath the forward end of the boiler, or on
+each side and exterior to the frame. The engines are non-condensing,
+and of the simplest possible construction. The whole machine is
+carried upon strong but flexible steel springs. The steam-pressure is
+usually more than 100 pounds. The pulling-power is generally about
+one-fifth the weight under most favorable conditions, and becomes as
+low as one-tenth on wet rails. The fuel employed is wood in new
+countries, coke in bituminous coal districts, and anthracite coal in
+the eastern part of the United States. The general arrangement and the
+proportions of locomotives differ somewhat in different localities.
+In Fig. 127, a British express-engine, _O_ is the boiler, _N_ the
+fire-box, _X_ the grate, _G_ the smoke-box, and _P_ the chimney. _S_
+is a spring and _R_ a lever safety-valve, _T_ is the whistle, _L_ the
+throttle or regulator valve, _E_ the steam-cylinder, and _W_ the
+driving-wheel. The force-pump, _B C_, is driven from the cross-head,
+_D_. The frame is the base of the whole system, and all other parts
+are firmly secured to it. The boiler is made fast at one end, and
+provision is made for its expansion when heated. Adhesion is
+secured by throwing a proper proportion of the weight upon the
+driving-wheel, _W_. This is from about 6,000 pounds on standard
+freight-engines, having several pairs of drivers, to 10,000 pounds on
+passenger-engines, per axle. The peculiarities of the American type
+(Fig. 128) are the truck, _I J_, or bogie, supporting the forward part
+of the engine, the system of equalizers, or beams which distribute the
+weight of the machine equally over the several axles, and minor
+differences of detail. The cab or house, _r_, protecting the
+engine-driver and fireman, is an American device, which is gradually
+coming into use abroad also. The American locomotive is distinguished
+by its flexibility and ease of action upon even roughly-laid roads. In
+the sketch, which shows a standard American engine in section, _A B_
+is the boiler, _C_ one of the steam-cylinders, _D_ the piston, _E_ the
+cross-head, connected to the crank-shaft, _F_, by the connecting-rod,
+_G H_ the driving-wheels, _I J_ the truck-wheels, carrying the truck,
+_K L_; _N N_ is the fire-box, _O O_ the tubes, of which but four are
+shown. The steam-pipe, _R S_, leads the steam to the valve-chest, _T_,
+in which is seen the valve, moved by the valve-gear, _U V_, and the
+link, _W_. The link is raised or depressed by a lever, _X_, moved from
+the cab. The safety-valve is seen at the top of the dome, at _Y_, and
+the spring-balance by which the load is adjusted is shown at _Z_. At
+_a_ is the cone-shaped exhaust-pipe, by which a good draught is
+secured. The attachments _b_, _c_, _d_, _e_, _f_, _g_--whistle,
+steam-gauge, sand-box, bell, head-light, and "cow-catcher"--are nearly
+all peculiar, either in construction or location, to the American
+locomotive. The cost of passenger-locomotives of ordinary size is
+about $12,000; heavier engines sometimes cost $20,000. The locomotive
+is usually furnished with a tender, which carries its fuel and water.
+The standard passenger-engine on the Pennsylvania Railroad has four
+driving-wheels, 5-1/2 feet diameter; steam-cylinders, 17 inches
+diameter and 2 feet stroke; grate-surface 15-1/2 square feet, and
+heating-surface 1,058 square feet. It weighs 63,100 pounds, of which
+39,000 pounds are on the drivers and 24,100 on the truck. The
+freight-engine has six driving-wheels, 54-5/8 inches in diameter. The
+steam-cylinders are 18 inches in diameter, stroke 22 inches,
+grate-surface 14.8 square feet, heating-surface 1,096 feet. It weighs
+68,500 pounds, of which 48,000 are on the drivers and 20,500 on the
+truck. The former takes a train of five cars up an average grade of 90
+feet to the mile. The latter is attached to a train of 11 cars. On a
+grade of 50 feet to the mile, the former takes 7 and the latter 17
+cars. Tank-engines for very heavy work, such as on grades of 320 feet
+to the mile, which are found on some of the mountain lines of road,
+are made with five pairs of driving-wheels, and with no truck. The
+steam-cylinders are 20-1/8 inches in diameter, 2 feet stroke;
+grate-area, 15-3/4 feet; heating-surface, 1,380 feet; weight with tank
+full, and full supply of wood, 112,000 pounds; average weight, 108,000
+pounds. Such an engine has hauled 110 tons up this grade at the speed
+of 5 miles an hour, the steam-pressure being 145 pounds. The adhesion
+was about 23 per cent. of the weight.
+
+In checking a train in motion, the inertia of the engine itself
+absorbs a seriously large portion of the work of the brakes. This is
+sometimes reduced by reversing the engine and allowing the
+steam-pressure to act in aid of the brakes. To avoid injury by
+abrasion of the surfaces of piston, cylinder, and the valves and
+valve-seats, M. Le Chatelier introduces a jet of steam into the
+exhaust-passages when reversing, and thus prevents the ingress of
+dust-laden air and the drying of the rubbing surfaces. This method of
+checking a train is rarely resorted to, however, except in case of
+danger. The introduction of the "continuous" or "air" brake, which can
+be thrown into action in an instant on every car of the train by the
+engine-driver, is so efficient that it is now almost universally
+adopted. It is one of the most important safeguards which American
+ingenuity has yet devised. In drawing a train weighing 150 tons at the
+rate of 60 miles an hour, about 800 effective horse-power is required.
+A speed of 80 miles an hour has been often attained, and 100 miles has
+probably been reached.
+
+The American locomotive-engine has a maximum life which may be stated
+at about 30 years. The annual cost of repairs is from 10 to 15 per
+cent. of its first cost. On moderately level roads, the engine
+requires a pint of oil to each 25 miles, and a ton of coal to each 40
+or 50 miles run. One of the best-managed railroads in the United
+States reports expenses as follows for one month:
+
+  Number "train-miles" run per ton of coal burned    53.95
+    "         "         "   "  quart of oil used     34.44
+  Passenger-cars hauled 1 mile per ton of coal      275.7
+  Other      "     "      "       "        "        634.8
+  Cost repairs per mile run                          $2 43
+   "   fuel       "      "                            3 64
+   "   oil and waste per mile run                       62
+   "   wages of engine-men per mile run               6 22
+  All other expenses per mile                         1 91
+  Total cost per "train-mile" run                    14 82
+
+Although the above sketch and description represent the construction
+and performance of the standard locomotive of the present time, there
+are indications that the compound arrangement of engines will
+ultimately be adopted. This will involve a considerable change of
+proportions, greatly increasing the volume and weight of
+steam-cylinders, but enabling the designer to more than proportionally
+decrease the weight of boiler and the quantity of fuel carried. There
+is no serious objection to their use, however, and no insuperable
+difficulty in the construction of the "double-cylinder" type of engine
+for the locomotive. A few such engines have already been put in
+service. In these engines the high-pressure cylinder is placed on one
+side and the larger low-pressure cylinder on the other side of the
+locomotive, thus having but two cylinders, as in the older plan. The
+valve-gear is the Stephenson link, as in the ordinary engine. At
+starting, the steam is allowed to act on both pistons; but after a few
+revolutions the course of the steam is changed, and the exhaust from
+the smaller cylinder, instead of passing into the chimney, is sent to
+the larger cylinder, which is at the same time cut off from the main
+steam-pipe. When the engine is ascending a steep gradient the steam
+may, if necessary, be taken from the boiler into both cylinders, as
+when starting. Compound engines of this kind have been used on the
+French line of railroad from Bayonne to Biarritz. They were designed
+by Mallet and built at Le Creuzot. The steam-cylinders are of 9-1/2
+and 15-3/4 inches diameter, and of 17-3/4 inches stroke of piston. The
+four driving-wheels are 4 feet in diameter, and the total weight of
+engine is 20 tons. The boiler has 484-1/2 square feet of
+heating-surface, and is built to carry 10 atmospheres pressure. When
+hauling trains of 50 tons at 25 miles an hour, these engines require
+about 15 pounds of good coal per mile.
+
+The total length of the railways in operation in the United States on
+the 1st day of January, 1877, was 76,640 miles,[93] being an average
+of one mile of railway for every 600 inhabitants. The railways are as
+follows:
+
+  [93] January, 1884, over 120,000 miles.
+
+                     Miles.
+
+  Alabama             1,722
+  Alaska                  0
+  Arizona                 0
+  Arkansas              787
+  California          1,854
+  Colorado              950
+  Connecticut           925
+  Dakota                290
+  Delaware              285
+  Florida               484
+  Georgia             2,308
+  Idaho                   0
+  Illinois            6,980
+  Indiana             4,072
+  Indian Territory      281
+  Iowa                3,937
+  Kansas              3,226
+  Kentucky            1,464
+  Louisiana             539
+  Maine                 987
+  Maryland            1,092
+  Massachusetts       1,825
+  Michigan            3,437
+  Minnesota           2,024
+  Mississippi         1,028
+  Missouri            3,016
+  Montana                 0
+  Nebraska            1,181
+  Nevada                714
+  New Hampshire         942
+  New Jersey          1,594
+  New Mexico              0
+  New York            5,520
+  North Carolina      1,371
+  Ohio                4,680
+  Oregon                251
+  Pennsylvania        5,896
+  Rhode Island          182
+  South Carolina      1,352
+  Tennessee           1,638
+  Texas               2,072
+  Utah                  486
+  Vermont               810
+  Virginia            1,648
+  Washington            110
+  West Virginia         576
+  Wisconsin           2,575
+  Wyoming               459
+                     ------
+    Total            76,640
+
+In 1873 came the great financial crisis, with its terrible results of
+interrupted production, poverty, and starvation, and an almost total
+cessation of the work of building new railroads. The largest number of
+miles ever built in any one year were constructed in 1872. The
+greatest mileage is in Illinois, reaching 6,589; the smallest in Rhode
+Island, 136, and in Washington Territory, 110. The State of
+Massachusetts has one mile of railroad to 4.86 miles of territory,
+this ratio being the greatest in the country. The longest road in
+operation is the Chicago & Northwestern, extending 1,500 miles; the
+shortest, the Little Saw-Mill Run Road in Pennsylvania, which is but
+three miles in length. The total capital of railways in the country is
+$6,000,000,000, or an average of $100,000 per mile. The earnings for
+the year 1872 amounted to $454,969,000, or $7,500 per mile. The
+largest net earnings recorded as made on any road were gained by the
+New York Central & Hudson River, $8,260,827; the smallest on several
+roads which not only earned nothing, but incurred a loss.
+
+The catastrophe of 1873-'74 revealed the fact that the latter
+condition of railroad finances was vastly more common than had been
+suspected; and it is still doubtful whether the existing immense
+network of railroads which covers the United States can be made, as a
+whole, to pay even a moderate return on the money invested in their
+construction. At the period of maximum rate of extension of railroads
+in the United States--1873--the reported lengths of the railroads of
+Europe and America were as follows:[94]
+
+  [94] _Railroad Gazette._
+
+              RAILROADS IN EUROPE AND AMERICA IN 1873.
+
+  ----------------------------+------------+-------------+------------
+       COUNTRIES.             | Railroads, | Population. |   Area,
+                              |   Miles.   |             | Sq. Miles.
+  ----------------------------+------------+-------------+------------
+  United States               |  71,565    |  40,232,000 | 2,492,316
+  Germany                     |  12,207    |  40,111,265 |   212,091
+  Austria                     |   5,865    |  35,943,592 |   227,234
+  France                      |  10,333    |  36,469,875 |   201,900
+  Russia in Europe            |   7,044    |  71,207,794 | 1,992,574
+  Great Britain, 1872         |  15,814    |  31,817,108 |   120,769
+  Belgium                     |   1,301    |   4,839,094 |    11,412
+  Netherlands                 |     886    |   3,858,055 |    13,464
+  Switzerland                 |     820    |   2,669,095 |    15,233
+  Italy                       |   3,667    |  26,273,776 |   107,961
+  Denmark                     |     420    |   1,784,741 |    14,453
+  Spain                       |   3,401    |  16,301,850 |   182,758
+  Portugal                    |     453    |   3,987,867 |    36,510
+  Sweden and Norway           |   1,049    |   5,860,122 |   188,771
+  Greece                      |     100    |   1,332,508 |    19,941
+  ----------------------------+------------+-------------+------------
+
+The railroads in Great Britain comprise over 15,000 miles of track now
+being worked in the United Kingdom, on which have been expended
+$2,800,000,000. This sum is equal to five times the amount of the
+annual value of all the real property in Great Britain, and two-thirds
+of the national debt. After deducting all the working expenses, the
+gross net annual revenue of all the roads exceeds by $110,000,000 the
+total revenue from all sources of Belgium, Holland, Portugal, Denmark,
+Sweden and Norway. An army of 100,000 officers and servants is in the
+employ of the companies, and the value of the rolling-stock exceeds
+$150,000,000.
+
+
+SECTION III.--MARINE ENGINES.
+
+The changes which have now become completed in the marine steam-engine
+have been effected at a later date than those which produced the
+modern locomotive. On the American rivers the modification of the
+beam-engine since the time of Robert L. Stevens has been very slight.
+The same general arrangement is retained, and the details are little,
+if at all, altered. The pressure of steam is sometimes as high as 60
+pounds per square inch.
+
+[Illustration: FIG. 130.--Beam-Engine.]
+
+The valves are of the disk or poppet variety, rising and falling
+vertically. They are four in number, two steam and two exhaust valves
+being placed at each end of the steam-cylinder. The beam-engine is a
+peculiarly American type, seldom if ever seen abroad. Fig. 130 is an
+outline sketch of this engine as built for a steamer plying on the
+Hudson River. This class of engine is usually adopted in vessels of
+great length, light draught, and high speed. But one steam-cylinder is
+commonly used. The cross-head is coupled to one end of the beam by
+means of a pair of links, and the motion of the opposite end of the
+beam is transmitted to the crank by a connecting-rod of moderate
+length. The beam has a cast-iron centre surrounded by a wrought-iron
+strap of lozenge shape, in which are forged the bosses for the
+end-centres, or for the pins to which the connecting-rod and the links
+are attached. The main centre of the beam is supported by a
+"gallows-frame" of timbers so arranged as to receive all stresses
+longitudinally. The crank and shaft are of wrought-iron. The
+valve-gear is usually of the form already mentioned as the Stevens
+valve-gear, the invention of Robert L. and Francis B. Stevens. The
+condenser is placed immediately beneath the steam-cylinder. The
+air-pump is placed close beside it, and worked by a rod attached to
+the beam. Steam-vessels on the Hudson River have been driven by such
+engines at the rate of 20 miles an hour. This form of engine is
+remarkable for its smoothness of operation, its economy and
+durability, its compactness, and the latitude which it permits in the
+change of shape of the long, flexible vessels in which it is generally
+used, without injury by "getting out of line."
+
+[Illustration: FIG. 131.--Oscillating Engine and Feathering
+Paddle-Wheel.]
+
+For paddle-engines of large vessels, the favorite type, which has been
+the side-lever engine, is now rarely built. For smaller vessels, the
+oscillating engine with feathering paddle-wheels is still largely
+employed in Europe. This style of engine is shown in Fig. 131. It is
+very compact, light, and moderately economical, and excels in
+simplicity. The usual arrangement is such that the feathering-wheel
+has the same action upon the water as a radial wheel of double
+diameter. This reduction of the diameter of the wheel, while retaining
+maximum effectiveness, permits a high speed of engine, and therefore
+less weight, volume, and cost. The smaller wheel-boxes, by offering
+less resistance to the wind, retard the progress of the vessel less
+than those of radial wheels. Inclined engines are sometimes used for
+driving paddle-wheels. In these the steam-cylinder lies in an inclined
+position, and its connecting-rod directly connects the crank with the
+cross-head. The condenser and air-pump usually lie beneath the
+cross-head guides, and are worked by a bell-crank driven by links on
+each side the connecting-rod, attached to the cross-head. Such engines
+are used to some extent in Europe, and they have been adopted in the
+United States navy for side-wheel gunboats. They are also used on the
+ferry-boats plying between New York and Brooklyn.
+
+[Illustration: FIG. 132.--The Two Rhode Islands, 1836-1876.]
+
+Among the finest illustrations of recent practice in the construction
+of side-wheel steamers are those built for the several routes between
+New York and the cities of New England which traverse Long Island
+Sound. Our illustration exhibits the form of these vessels, and also
+shows well the modifications in structure and size which have been
+made during this generation. The later vessel is 325 feet long, 45
+feet beam, 80 feet wide over the "guards," and 16 feet deep, drawing
+10 feet of water. The "frames" upon which the planking of the hull is
+fastened are of white-oak, and the lighter and "top" timbers of cedar
+and locust. The engine has a steam-cylinder 90 inches in diameter and
+12 feet stroke of piston.[95] On each side the great saloons which
+extend from end to end of the upper deck are state-rooms, containing
+each two berths and elegantly furnished. The engine of this vessel is
+capable of developing about 2,500 horse-power. The great wheels, of
+which the paddle-boxes are seen rising nearly to the height of the
+hurricane-deck, are 37-1/2 feet in diameter and 12 in breadth. The
+hull of this vessel, including all wood-work, weighs over 1,200 tons.
+The weight of the machinery is about 625 tons. The steamer makes 16
+knots an hour when the engine is at its best speed--about 17
+revolutions per minute--and its average speed is about 14 knots on
+its route of 160 miles. The coal required to supply the furnaces of
+such a vessel and with such machinery would be about 3 tons per hour.
+or a little over 2-1/2 pounds per horse-power. The construction of
+such a vessel occupies, usually, about a year, and costs a quarter of
+a million dollars.
+
+  [95] The steam-cylinders of the engines of steamers Bristol and
+  Providence are 110 inches in diameter and of 12 feet stroke.
+
+[Illustration: FIG. 133.--A Mississippi Steamboat.]
+
+The non-condensing direct-acting engine is used principally on the
+Western rivers, driven by steam of from 100 to 150 pounds pressure,
+and exhausts its steam into the atmosphere. It is the simplest
+possible form of direct-acting engine. The valves are usually of the
+"poppet" variety, and are operated by cams which act at the ends of
+long levers having their fulcra on the opposite side of the valve, the
+stem of which latter is attached at an intermediate point. The engine
+is horizontal, and the connecting-rod directly attached to cross-head
+and crank-pin without intermediate mechanism. The paddle-wheel is
+used, sometimes as a stern-wheel, as in the plan of Jonathan Hulls of
+one and a half century ago, sometimes as a side-wheel, as is most
+usual elsewhere. One of the most noted of these steamers, plying on
+the Mississippi, is shown in the preceding sketch.
+
+One of the largest of these steamers was the Grand Republic,[96] a
+vessel 340 feet long, 56 feet beam, and 10-1/4 feet depth. The draught
+of water of this great craft was 3-1/2 feet forward and 4-1/2 aft. The
+two sets of compound engines, 28 and 56 inches diameter and of 10 feet
+stroke, drive wheels 38-1/2 feet in diameter and 18 feet wide. The
+boilers were steel. A steamer built still later on the Ohio has the
+following dimensions: Length, 225 feet; breadth, 35-1/2 feet; depth, 5
+feet; cylinders, 17-3/8 inches in diameter, 6 feet stroke; three
+boilers. The hull and cabin were built at Jeffersonville, Ind. She has
+40 large state-rooms. The cost of the steamer was $40,000.
+
+  [96] Burned in 1877.
+
+These vessels have now opened to commerce the whole extent of the
+great Mississippi basin, transporting a large share of the products of
+a section of country measuring a million and a half square miles--an
+area equal to many times that of New York State, and twelve times that
+of the island of Great Britain--an area exceeding that of the whole of
+Europe, exclusive of Russia and Turkey, and capable, if as thoroughly
+cultivated as the Netherlands, of supporting a population of between
+three and four hundred millions of people.
+
+The steam-engine and propelling apparatus of the modern ocean-steamer
+have now become almost exclusively the compound or double-cylinder
+engine, driving the screw. The form and the location of the machinery
+in the vessel vary with the size and character of the ship which it
+drives. Very small boats are fitted with machinery of quite a
+different kind from that built for large steamers, and war-vessels
+have usually been supplied with engines of a design radically
+different from that adopted for merchant-steamers.
+
+[Illustration: FIG. 134.--Steam-Launch, New York Steam-Power Company.]
+
+The introduction of _Steam-Launches_ and small pleasure-boats driven
+by steam-power is of comparatively recent date, but their use is
+rapidly increasing. Those first built were heavy, slow, and
+complicated; but, profiting by experience, light and graceful boats
+are now built, of remarkable swiftness, and having such improved and
+simplified machinery that they require little fuel and can be easily
+managed. Such boats have strong, carefully-modeled hulls, light and
+strong boilers, capable of making a large amount of dry steam with
+little fuel, and a light, quick-running engine, working without shake
+or jar, and using steam economically.
+
+[Illustration: FIG. 135.--Launch-Engine.]
+
+The above sketch represents the engine built by a New York firm for
+such little craft. This is the smallest size made for the market. It
+has a steam-cylinder 3 inches in diameter and a stroke of piston of 5
+inches, driving a screw 26 inches in diameter and of 3 feet pitch. The
+maximum power of the engine is four or five times the nominal power.
+The boiler is of the form shown in the illustrations of semi-portable
+engines, and has a heating-surface, in this case, of 75 square feet.
+The boat itself is like that seen on page 386, and is 25 feet long, of
+5 feet 8 inches beam, and draws 2-1/4 feet of water. These little
+machines weigh about 150 pounds per nominal horse-power, and the
+boilers about 300.
+
+Some of these little vessels have attained wonderful speed. A British
+steam-yacht, the Miranda, 45-1/2 feet in length, 5-3/4 feet wide, and
+drawing 2-1/2 feet of water, with a total weight of 3-3/4 tons, has
+steamed nearly 18-1/2 miles an hour for short runs. The boat was
+driven by an engine of 6 inches diameter of cylinder and 8 inches
+stroke of piston, making 600 revolutions per minute, driving a
+two-bladed screw 2-1/2 feet in diameter and of 3-1/3 feet pitch. Its
+machinery had a total weight of two tons. Another English yacht, the
+Firefly, is said to have made 18.94 miles an hour. A little French
+yacht, the Hirondelle, has attained a speed of 16 knots, equal to
+about 18-1/2 miles, an hour. This was, however, a much larger vessel
+than the preceding. One of the most remarkable of these little
+steamers is a torpedo-boat built for the United States navy. This
+vessel is 60 feet long, 6 feet wide, and 5 feet deep; its screw is 38
+inches in diameter and of 5 feet pitch, two-bladed, and is driven, by
+a very light engine and boiler, 400 revolutions per minute, the boat
+attaining a speed of 19 to 20 miles an hour. Another little vessel,
+the Vision, made nearly as great speed, developing 20 horse-power with
+engine and boiler weighing but about 400 pounds.
+
+Yachts of high speed require such weight and bulk of engine that but
+little space is left for cabins, and they are usually exceedingly
+uncomfortable vessels. In the Miranda the weight of machinery is more
+than one-half the total weight of the whole. An illustration of the
+more comfortable and more generally liked pleasure-yacht is the Day
+Dream. The length is 105 feet, and the boat draws 5-1/2 feet of
+water. There are two engines, having steam-cylinders 14 inches in
+diameter and of the same length of stroke, direct-acting, condensing,
+and driving a screw, of 7 feet diameter and of 10-1/2 feet pitch, 135
+revolutions a minute, giving the yacht a speed of 13-1/2 knots an
+hour.
+
+[Illustration: FIG. 136.--Horizontal, Direct-acting Naval
+Screw-Engine.]
+
+In larger vessels, as in yachts, in nearly all cases, the ordinary
+screw-engine is direct-acting. Two engines are placed side by side,
+with cranks on the shaft at an angle of 90° with each other. In
+merchant-steamers the steam-cylinders are usually vertical and
+directly over the crank-pins, to which the cross-heads are coupled.
+The condenser is placed behind the engine-frame, or, where a
+jet-condenser is used, the frame itself is sometimes made hollow, and
+serves as a condenser. The air-pump is worked by a beam connected by
+links with the cross-head. The general arrangement is like that shown
+in Figs. 137 and 138. For naval purposes such a form is objectionable,
+since its height is so great that it would be exposed to injury by
+shot. In naval engineering the cylinder is placed horizontally, as in
+Fig. 136, which is a sectional view, representing an horizontal,
+direct-acting naval screw-engine, with jet-condenser and double-acting
+air and circulating pumps. _A_ is the steam-cylinder, _B_ the piston,
+which is connected to the crank-pin by the piston-rod, _D_, and
+connecting-rod, _E_. _F_ is the cross-head guide. The eccentrics,
+_G_, operate the valve, which is of the "three-ported variety," by a
+Stephenson link. Reversing is effected by the hand-wheel, _C_, which,
+by means of a gear, _m_, and a rack, _k_, elevates and depresses the
+link, and thus reverses the valve.
+
+[Illustration: FIG. 137.--Compound Marine Engine. Side Elevation.]
+
+The trunk-engine, in which the connecting-rod is attached directly to
+the piston and vibrates within a trunk or cylinder secured to the
+piston, moving with it, and extending outside the cylinder, like an
+immense hollow piston-rod, is frequently used in the British navy. It
+has rarely been adopted in the United States.
+
+[Illustration: FIG. 138.--Compound Marine Engine. Front Elevation and
+Section.]
+
+In nearly all steam-vessels which have been built for the merchant
+service recently, and in some naval vessels, the compound engine has
+been adopted. Figs. 137 and 138 represent the usual form of this
+engine. Here _A A_, _B B_ are the small and the large, or the
+high-pressure and the low-pressure cylinders respectively. _C C_ are
+the valve-chests. _G G_ is the condenser, which is invariably a
+surface-condenser. The condensing water is sometimes directed around
+the tubes contained within the casing, _G G_, while the steam is
+exhausted around them and among them, and sometimes the steam is
+condensed within the tubes, while the injection-water which is sent
+into the condenser to produce condensation passes around the exterior
+of the tubes. In either case, the tubes are usually of small diameter,
+varying from five-eighths to half an inch, and in length from four to
+seven feet. The extent of heating-surface is usually from one-half to
+three-fourths that of the heating-surface of the boilers.
+
+The air and circulating pumps are placed on the lower part of the
+condenser-casting, and are operated by a crank on the main shaft at
+_N_; or they are sometimes placed as in the style of engine last
+described, and driven by a beam worked by the cross-head. The
+piston-rods, _T S_, are guided by the cross-heads, _V V_, working in
+slipper-guides, and to these cross-heads are attached the
+connecting-rods, _X X_, driving the cranks, _M M_. The cranks are now
+usually set at right angles; in some engines this angle is increased
+to 120°, or even 180°. Where it is arranged as here shown, an
+intermediate reservoir, _P O_, is placed between the two cylinders to
+prevent the excessive variations of pressure that would otherwise
+accompany the varying relative motions of the pistons, as the steam
+passes from the high-pressure to the low-pressure cylinder. Steam from
+the boilers enters the high-pressure steam-chest, _X_, and is admitted
+by the steam-valve alternately above and below the piston as usual.
+The exhaust steam is conducted through the exhaust passage around into
+the reservoir, _P_, whence it it is taken by the low-pressure
+cylinder, precisely as the smaller cylinder drew its steam from the
+boiler. From the large or low-pressure cylinder the steam is exhausted
+into the condenser. The valve-gear is usually a Stephenson link, _g
+e_, the position of which is determined, and the reversal of which is
+accomplished, by a hand-wheel, _o_, and screw, _m n p_, which, by the
+bell-crank, _k i_, are attached to the link, _g e_. The "box-framing"
+forms also the hot-well. The surface-condenser is cleared by a
+single-acting air-pump, inside the frame, at _T_. The feed-pump and
+the bilge-pumps are driven from the cross-head of the air-pump.
+
+[Illustration: John Elder.]
+
+The successful introduction of the double-cylinder engine was finally
+accomplished by the exertions of a few engineers, who were at once
+intelligent enough to understand its advantages, and energetic and
+enterprising enough to push it forward in spite of active opposition,
+and powerful enough, pecuniarily and in influence, to succeed. The
+most active and earnest of these eminent men was John Elder, of the
+firm of Randolph, Elder & Co., subsequently John Elder & Co., of
+Glasgow.[97]
+
+  [97] _Vide_ "Memoir of John Elder," W. J. M. Rankine, Glasgow, 1871.
+
+Elder was of Scotch descent. His ancestors had, for generations,
+shown great skill and talent in construction, and had always been
+known as successful millwrights. John Elder was born at Glasgow, March
+8, 1824, and died in London, September 17, 1869. He was educated at
+the Glasgow High-School and in the College of Engineering at the
+University of Glasgow, where, however, his attendance was but for a
+short time. He learned the trade under his father in the workshops of
+the Messrs. Napier, and became an unusually expert draughtsman. After
+spending three years in charge of the drawing-office at the
+engine-building works of Robert Napier, where his father had been
+manager, Elder became a partner in the firm which had previously been
+known as Randolph, Elliott & Co., in the year 1852. The firm commenced
+building iron vessels in 1860.
+
+In the mean time, the experiments of Hornblower and Wolff, of Allaire
+and Smith, and of McNaught, Craddock, and Nicholson, together with the
+theoretical investigations of Thompson, Rankine, Clausius, and others,
+had shown plainly in what direction to look for improvement upon then
+standard engines, and what direction practice was taking with all
+types. The practical deductions which were becoming evident were
+recognized very early by Elder, and he promptly began to put in
+practice the principles which his knowledge of thermo-dynamics and of
+mechanics enabled him to appreciate. He adopted the compound engine,
+and coupled his cranks at angles of 180°, in order to avoid losses due
+to the friction of the crank-shaft in its bearings, by effecting a
+partial counterbalancing of pressures on the journals. Elder was one
+of the first to point out the fact that the compound engine had proved
+itself more efficient than the single-cylinder engine, only when the
+pressure of steam carried and the extent to which expansion was
+adopted exceeded the customary practice of his time. His own practice
+was, from the first, successful, and from 1853 to 1867 he and his
+partners were continually engaged in the construction of steamers and
+fitting them with compound engines.
+
+The engines of their first vessel, the Brandon, required but 3-1/4
+pounds of coal per hour and per horse-power, in 1854, when the usual
+consumption was a third more. Five years later, they had built engines
+which consumed a third less than those of the Brandon; and
+thenceforward, for many years, their engines, when of large size,
+exhibited what was then thought remarkable economy, running on a
+consumption of from 2-1/4 to 2-1/2 pounds.
+
+In the year 1865 the British Government ordered a competitive trial of
+three naval vessels, which only differed in the form of their engines.
+The Arethusa was fitted with trunk-engines of the ordinary kind; the
+Octavia had three steam-cylinders, coupled to three cranks placed at
+angles of 120° with each other; and the Constance was fitted with
+compound engines, two sets of three cylinders each, and each taking
+steam from the boiler into one cylinder, passing it through the other
+two with continuous expansion, and finally exhausting from the third
+into the condenser. These vessels, during one week's steaming at sea,
+averaged, respectively, 3.64, 3.17, and 2.51 pounds of coal per hour
+and per horse-power, and the Constance showed a marked superiority in
+the efficiency of the mechanism of her engines, when the losses by
+friction were compared.
+
+The change from the side-lever single-cylinder engine, with
+jet-condenser and paddle-wheels, to the direct-acting compound engine,
+with surface-condenser and screw-propellers, has occurred within the
+memory and under the observation of even young engineers, and it may
+be considered that the revolution has not been completely effected.
+This change in the design of engine is not as great as it at first
+seemed likely to become. Builders have but slowly learned the
+principles stated above in reference to expansion in one or more
+cylinders, and the earlier engines were made with a high and low
+pressure cylinder working on the same connecting-rod, and each machine
+consisted of four steam-cylinders. It was at last discovered that a
+high-pressure single-cylinder engine exhausting into a separate
+larger low-pressure engine might give good results, and the compound
+engine became as simple as the type of engine which it displaced. This
+independence of high and low pressure engines is not in itself novel,
+for the plan of using the exhaust of a high-pressure engine to drive a
+low-pressure condensing engine was one of the earliest of known
+combinations.
+
+The advantage of introducing double engines at sea is considerably
+greater than on land. The coal carried by a steam-vessel is not only
+an item of great importance in consequence of its first cost, but,
+displacing its weight or bulk of freight which might otherwise be
+carried, it represents so much non-paying cargo, and is to be charged
+with the full cost of transportation in addition to first cost. The
+best of steam-coal is therefore usually chosen for steamers making
+long voyages, and the necessity of obtaining the most economical
+engines is at once seen, and is fully appreciated by steamship
+proprietors. Again, an economy of one-fourth of a pound per
+horse-power per hour gives, on a large transatlantic steamer, a saving
+of about 100 tons of coal for a single voyage. To this saving of cost
+is to be added the gain in wages and sustenance of the labor required
+to handle that coal, and the gain by 100 tons of freight carried in
+place of the coal.
+
+For many years the change which has here been outlined, in the forms
+of engine and the working of steam expansively, was retarded by the
+inefficiency of methods and tools used in construction. With gradual
+improvement in tools and in methods of doing work, it became possible
+to control higher steam and to work it successfully; and the change in
+this direction has been steadily going on up to the present time with
+all types of steam-engine. At sea this rise of pressure was for a
+considerable time retarded by the serious difficulty encountered in
+the tendency of the sulphate of lime to deposit in the boiler. When
+steam-pressure had risen to 25 pounds per square inch, it was found
+that no amount of "blowing out" would prevent the deposition of
+seriously large quantities of this salt, while at the lower pressures
+at first carried at sea no troublesome precipitation occurred, and the
+only precaution necessary was to blow out sufficient brine to prevent
+the precipitation of common salt from a supersaturated solution. The
+introduction of surface-condensation was promptly attempted as the
+remedy for this evil, but for many years it was extremely doubtful
+whether its disadvantages were not greater than its advantages. It was
+found very difficult to keep the condensers tight, and boilers were
+injured by some singular process of corrosion, evidently due to the
+presence of the surface-condenser. The simple expedient of permitting
+a very thin scale to form in the boiler was, after a time, hit upon as
+a means of overcoming this difficulty, and thenceforward the greatest
+obstacle to the general introduction was the conservative disposition
+found among those who had charge of marine machinery, which
+conservatism regarded with suspicion every innovation. Another trouble
+arose from the difficulty of finding men neither too indolent nor too
+ignorant to take charge of the new condenser, which, more complicated
+and more readily disarranged than the old, demanded a higher class of
+attendants. Once introduced, however, the surface-condenser removed
+the obstacle to further elevation of steam-pressure, and the rise from
+20 to 60 pounds pressure soon occurred. Elder and his competitors on
+the Clyde were the first to take advantage of the fact when these
+higher pressures became practicable.
+
+The lightness of engine and the smaller weight of boiler secured when
+the simpler type of "compound" engine is used are great advantages,
+and, when coupled with the fact that by no other satisfactory device
+can great expansion and consequent economy of fuel be obtained at sea,
+the advantages are such as to make the adoption of this style of
+engine imperative for ship-propulsion.
+
+This extreme lightness in machinery has been largely, also, the result
+of very careful and skillful designing, of intelligent construction,
+and of care in the selection and use of material. British builders
+had, until after the introduction of these later types of
+vessels-of-war, been distinguished rather by the weight of their
+machinery than for nice calculation and proportioning of parts. Now
+the engines of the heavy iron-clads are models of good proportions,
+excellence in materials, and of workmanship, which are well worthy of
+study. The weight per indicated horse-power has been reduced from 400
+or 500 pounds to less than half that amount within the last ten years.
+This has been accomplished by forcing the boilers--although thus, to
+some extent, losing economy--by higher steam-pressure, a very much
+higher piston-speed, reduction of friction of parts, reduction of
+capacity for coal-stowage, and exceedingly careful proportioning.
+The reduction of coal-bunker capacity is largely compensated by
+the increase of economy secured by superheating, by increased
+expansion, elevation of piston-speed, and the introduction of
+surface-condensation.
+
+A good marine steam-engine of the form which was considered standard
+15 or 20 years ago, having low-pressure boilers carrying steam at 20
+or 25 pounds pressure as a maximum, expanding twice or three times,
+and having a jet-condenser, would require about 30 or 35 pounds of
+feed-water per horse-power per hour; substituting surface-condensation
+for that produced by the jet brought down the weight of steam used to
+from 25 to 30 pounds; increasing steam-pressure to 60 pounds,
+expanding from five to eight times, and combining the special
+advantages of the superheater and the compound engine with
+surface-condensation, has reduced the consumption of steam to 20, or
+even, in some cases, 15 pounds of steam per horse-power per hour.
+Messrs. Perkins, of London, guarantee, as has already been stated, to
+furnish engines capable of giving a horse-power with a consumption of
+but 1-1/4 pound of coal. Mr. C. E. Emery reports the United States
+revenue-steamer Hassler, designed by him, to have given an ordinary
+sea-going performance which is probably fully equal to anything yet
+accomplished. The Hassler is a small steamer, of but 151 feet in
+length, 24-1/2 feet beam, and 10 feet draught. The engines have
+steam-cylinders 18.1 and 28 inches diameter, respectively, and of 28
+inches stroke of piston, indicating 125 horse-power; with steam at 75
+pounds pressure, and at a speed of but 7 knots, the coal consumed was
+but 1.87 pound per horse-power per hour.
+
+The committee of the British Admiralty on designs of ships-of-war have
+reported recently: "The carrying-power of ships may certainly be to
+some extent increased by the adoption of compound engines in her
+Majesty's service. Its use has recently become very general in the
+mercantile marine, and the weight of evidence in favor of the large
+economy of fuel thereby gained is, to our minds, overwhelming and
+conclusive. We therefore beg earnestly to recommend that the use of
+compound engines may be generally adopted in ships-of-war hereafter to
+be constructed, and applied, whenever it can be done with due regard
+to economy and to the convenience of the service, to those already
+built."
+
+The forms of screws now employed are exceedingly diverse, but those in
+common use are not numerous. In naval vessels it is common to apply
+screws of two blades, that they may be hoisted above water into a
+"well" when the vessel is under sail, or set with the two blades
+directly behind the stern-post, when their resistance to the forward
+motion of the vessel will be comparatively small. In other vessels,
+and in the greater number of full-power naval vessels, screws of three
+or four blades are used.
+
+The usual form of screw (Fig. 139) has blades of nearly equal breadth
+from the hub to the periphery, or slightly widening toward their
+extremities, as is seen in an exaggerated degree in Fig. 140,
+representing the form adopted for tug-boats, where large surface near
+the extremity is more generally used than in vessels of high speed
+running free. In the Griffith screw, which has been much used, the hub
+is globular and very large. The blades are secured to the hub by
+flanges, and are bolted on in such a manner that their position may be
+changed slightly if desired. The blades are shaped like the section of
+a pear, the wider part being nearest the hub, and the blades tapering
+rapidly toward their extremities. A usual form is intermediate between
+the last, and is like that shown in Fig. 141, the hub being
+sufficiently enlarged to permit the blades to be attached as in the
+Griffith screw, but more nearly cylindrical, and the blades having
+nearly uniform width from end to end.
+
+[Illustration: FIG. 139.--Screw-Propeller.]
+
+[Illustration: FIG. 140.--Tug-boat Screw.]
+
+[Illustration: FIG. 141.--Hirsch Screw.]
+
+The pitch of a screw is the distance which would be traversed by the
+screw in one revolution were it to move through the water without
+slip; i. e., it is double the distance _C D_, Fig. 140. _C D´_
+represents the helical path of the extremity of the blade _B_, and _O
+E F H K_ is that of the blade _A_. The proportion of diameter to the
+pitch of the screw is determined by the speed of the vessel. For low
+speed the pitch may be as small as 1-1/4 the diameter. For vessels of
+high speed the pitch is frequently double the diameter. The diameter
+of the screw is made as great as possible, since the slip decreases
+with the increase of the area of screw-disk. Its length is usually
+about one-sixth of the diameter. A greater length produces loss by
+increase of surface causing too great friction, while a shorter screw
+does not fully utilize the resisting power of the cylinder of water
+within which it works, and increased slip causes waste of power. An
+empirical value for the probable slip in vessels of good shape, which
+is closely approximate usually, is _S_ = 4(_M_/_A_), in which _S_ is
+the slip per cent., and _M_ and _A_ are the areas of the midship
+section and of the screw-disk in square feet.
+
+The most effective screws have slightly greater pitch at the periphery
+than at the hub, and an increasing pitch from the forward to the rear
+part of the screw. The latter method of increasing pitch is more
+generally adopted alone. The thrust of the screw is the pressure which
+it exerts in driving the vessel forward. In well-formed vessels, with
+good screws, about two-thirds of the power applied to the screw is
+utilized in propulsion, the remainder being wasted in slip and other
+useless work. Its efficiency is in such a case, therefore, 66 per
+cent. Twin screws, one on each side of the stern-post, are sometimes
+used in vessels of light draught and considerable breadth, whereby
+decreased slip is secured.
+
+As has already been stated, the introduction of the compound engine
+has been attempted, but with less success than in Europe, by several
+American engineers.
+
+The most radical change in the methods of ship-propulsion which has
+been successfully introduced in some localities has been the adoption
+of a system of "wire-rope towage." It is only well adapted for cases
+in which the steamer traverses the same line constantly, moving
+backward and forward between certain points, and is never compelled to
+deviate to any considerable extent from the path selected. A similar
+system is in use in Canada, but it has not yet come into use in the
+United States, notwithstanding the fact that, wherever its adoption is
+practicable, it has a marked superiority in economy over the usual
+methods of propulsion. With chain or rope traction there is no loss by
+slip or oblique action, as in both screw and paddle-wheel propulsion.
+In the latter methods these losses amount to an important fraction of
+the total power; they rarely, if ever, fall below a total of 25 per
+cent., and probably in towage exceed 50 per cent. The objection to the
+adoption of chain-propulsion, as it is also often called, is the
+necessity of following closely the line along which the chain or the
+rope is laid. There is, however, much less difficulty than would be
+anticipated in following a sinuous route or in avoiding obstacles in
+the channel or passing other vessels. The system is particularly well
+adapted for use on canals.
+
+The steam-boilers in use in the later and best marine engineering
+practice are of various forms, but the standard types are few in
+number. That used on river-steamers in the United States has already
+been described.
+
+[Illustration: FIG. 142.--Marine Fire-tubular Boiler. Section.]
+
+Fig. 142 is a type of marine tubular boiler which is in most extensive
+use in sea-going steamers for moderate pressure, and particularly for
+naval vessels. Here the gases pass directly into the back connection
+from the fire, and thence forward again, through horizontal tubes, to
+the front connection and up the chimney. In naval vessels the
+steam-chimney is omitted, as it is there necessary to keep all parts
+of the boiler as far below the water-line as possible. Steam is taken
+from the boiler by pipes which are carried from end to end of the
+steam-space, near the top of the boiler, the steam entering these
+pipes through small holes drilled on the other side. Steam is thus
+taken from the boiler "wet," but no large quantity of water can
+usually be "entrained" by the steam.
+
+A marine boiler has been quite extensively introduced into the United
+States navy, in which the gases are led from the back connection
+through a tube-box around and among a set of upright water-tubes,
+which are filled with water, circulation taking place freely from the
+water-space immediately above the crown-sheet of the furnace up
+through these tubes into the water-space above them. These
+"water-tubular" boilers have a slight advantage over the
+"fire-tubular" boilers already described in compactness, in steaming
+capacity, and in economical efficiency. They have a very marked
+advantage in the facility with which the tubes may be scraped or freed
+from the deposit when a scale of sulphate of lime or other salt has
+formed within them by precipitation from the water. The fire-tubular
+boiler excels in convenience of access for plugging up leaking tubes,
+and is much less costly than the water-tubular. The water-tube class
+of boilers still remain in extensive use in the United States naval
+steamers. They have never been much used in the merchant service,
+although introduced by James Montgomery in the United States and by
+Lord Dundonald in Great Britain twenty years earlier. Opinion still
+remains divided among engineers in regard to their relative value.
+They are gradually reassuming prominence by their introduction in the
+modified form of sectional boilers.
+
+[Illustration: FIG. 143.--Marine High-Pressure Boiler. Section.]
+
+Marine boilers are now usually given the form shown in section in Fig.
+143. This form of boiler is adopted where steam-pressures of 60
+pounds and upward are carried, as in steam-vessels supplied with
+compound engines, cylindrical forms being considered the best with
+high pressures. The large cylindrical flues, therefore, form the
+furnaces as shown in the transverse sectional view. The gases rise, as
+shown in the longitudinal section, through the connection, and pass
+back to the end of the boiler through the tubes, and thence, instead
+of entering a steam-chimney, they are conducted by a smoke-connection,
+not shown in the sketch, to the smoke funnel or stack. In
+merchant-steamers, a steam-drum is often mounted horizontally above
+the boiler. In other cases a separator is attached to the steam-pipe
+between boilers and engines. This usually consists of an iron tank,
+divided by a vertical partition extending from the top nearly to the
+bottom. The steam, entering the top at one side of this partition,
+passes underneath it, and up to the top on the opposite side, where it
+issues into a steam-pipe leading directly to the engine. The sudden
+reversal of its course at the bottom causes it to leave the suspended
+water in the bottom of the separator, whence it is drained off by
+pipes.
+
+The most interesting illustrations of recent practice in marine
+engineering and naval architecture are found in the steamers which are
+now seen on transoceanic routes for the merchant service, and, in the
+naval service, in the enormous iron-clads which have been built in
+Great Britain.
+
+The City of Peking is one of the finest examples of American practice.
+This vessel was constructed for the Pacific Mail Company. The hull is
+423 feet long, of 48 feet beam, and 38-1/2 feet deep. Accommodations
+are furnished for 150 cabin and 1,800 steerage passengers, and the
+coal-bunkers "stow" 1,500 tons of coal. The iron plates of which the
+sides and bottom are made are from 11/16 to one inch in thickness. The
+weight of iron used in construction was about 5,500,000 pounds. The
+machinery weighed nearly 2,000,000 pounds, with spare gear and
+accessory apparatus. The engines are compound, with two
+steam-cylinders of 51 inches and two of 88 inches diameter, and a
+stroke of piston of 4-1/2 feet. The condensing water is sent through
+the surface-condensers by circulating-pumps driven by their own
+engines. Ten boilers furnish steam to these engines, each having a
+diameter of 13 feet, a length of 13-1/2 feet, and a thickness of
+"shell" of 13/16 inch. Each has three furnaces, and contains 204
+tubes of an outside diameter of 3-1/4 inches. All together, they
+have 520 square feet of grate-surface and 17,000 square feet of
+heating-surface. The area of cooling-surface in the condensers is
+10,000 square feet. The City of Rome, a ship of later design, is 590
+feet long, "over all," 52 feet beam, 52 feet deep, and measures 8,300
+tons. The engines, of 8,500 horse-power, will drive the vessel 18
+knots (21 miles) an hour; they have six steam-cylinders (three high
+and three low pressure), and are supplied with steam by 8 boilers
+heated by 48 furnaces. The hull is of steel, the bottom double, and
+the whole divided into ten compartments by transverse bulkheads. Two
+longitudinal bulkheads in the engine and boiler compartments add
+greatly to the safety of the vessel.
+
+The most successful steam-vessels in general use are these
+screw-steamers of transoceanic lines. Those of the transatlantic lines
+are now built from 350 to 550 feet long, generally propelled from 12
+to 18 knots (14 to 21 miles) an hour, by engines of from 3,000 to
+8,000 horse-power, consuming from 70 to 250 tons of coal a day, and
+crossing the Atlantic in from eight to ten days. These vessels are now
+invariably fitted with the compound engine and surface-condensers. One
+of these vessels, the Germanic, has been reported at Sandy Hook, the
+entrance to New York Harbor, in 7 days 11 hours 37 minutes from
+Queenstown--a distance, as measured by the log and by observation, of
+2,830 miles. Another steamer, the Britannic, has crossed the Atlantic
+in 7 days 10 hours and 53 minutes. These vessels are of 5,000 tons
+burden, of 750 "nominal" horse-power (probably 5,000 actual).
+
+[Illustration: FIG. 144.--The Modern Steamship.]
+
+The modern steamship is as wonderful an illustration of ingenuity and
+skill in all interior arrangements as in size, power, and speed. The
+size of sea-going steamers has become so great that it is unsafe to
+intrust the raising of the anchor or the steering of the vessel to
+manual power and skill; and these operations, as well as the loading
+and unloading of the vessel, are now the work of the same great
+motor--steam.
+
+The now common form of auxiliary engine for controlling the helm is
+one of the inventions of the American engineer F. E. Sickels, who
+devised the "Sickels cut-off," and was first invented about 1850. It
+was exhibited at London at the International Exhibition of 1851. It
+consists[98] principally of two cylinders working at right angles upon
+a shaft geared into a large wheel fastened by a friction-plate lined
+with wood, and set by a screw to any desired pressure on the
+steering-apparatus. The wheel turned by the steersman is connected
+with the valve-gear of the cylinders, so that the steam, or other
+motor, will move the rudder precisely as the helmsman moves the wheel
+adjusting the steam-valves. This wheel thus becomes the
+steering-wheel. The apparatus is usually so arranged that it may be
+connected or disconnected in an instant, and hand-steering adopted if
+the smoothness of the sea and the low speed of the vessel make it
+desirable or convenient. This method was first adopted in the United
+States on the steamship Augusta.
+
+  [98] "Official Catalogue," 1862, vol. iv., Class viii., p. 123.
+
+The same inventor and others have contrived "steam-windlasses," some
+of which are in general use on large vessels. The machinery of these
+vessels is also often fitted with a steam "reversing-gear," by means
+of which the engines are as easily man[oe]uvred as are those of the
+smallest vessels, to which hand-gear is always fitted. In one of these
+little auxiliary engines, as devised by the author, a small handle
+being adjusted to a marked position, as to the point marked "stop" on
+an index-plate, the auxiliary engine at once starts, throws the
+valve-gear into the proper position--as, if a link-motion, into
+"middle-gear"--thus stopping the large engines, and then it itself
+stops. Setting the handle so that its pointer shall point to "ahead,"
+the little engine starts again, sets the link in position to go ahead,
+thus starting the large engines, and again stops itself. If set at
+"back," the same series of operations occurs, leaving the main engines
+backing and the little "reversing engine" stopped. A number of forms
+of reversing engine are in use, each adapted to some one type of
+engine.
+
+The hull of the transatlantic steamer is now always of iron, and is
+divided into a number of "compartments," each of which is water-tight
+and separated from the adjacent compartments by iron "bulkheads," in
+which are fitted doors which, when closed, are also water-tight. In
+some cases these doors close automatically when the water rises in the
+vessel, thus confining it to the leaking portion.
+
+Thus we have already seen a change in transoceanic lines from steamers
+like the Great Western (1837), 212 feet in length, of 35-1/2 feet
+beam, and 23 feet depth, driven by engines of 450 horse-power, and
+requiring 15 days to cross the Atlantic, to steamships over 550 feet
+long, 55 feet beam, and 55 feet deep, with engines of 10,000
+horse-power, crossing the Atlantic in 7 days; iron substituted for
+wood in construction, the cost of fuel reduced one-half, and the speed
+raised from 8 to 18 knots and over. In the earlier days of steamships
+they were given a proportion of length to breadth of from 5 to 6 to 1;
+in forty years the proportion increased until 11 to 1 was reached.
+
+The whole naval establishment of every country has been greatly
+modified by the recent changes in methods of attack and defense; but
+the several classes of ships which still form the naval marine are all
+as dependent upon their steam-machinery as ever.
+
+[Illustration: H. B. M. Iron-Clad Captain. H. B. M. Iron-Clad
+Thunderer. U. S. Iron-Clad Dictator. U. S. Iron-Clad Monitor. H. B. M.
+Iron-Clad Giatton. French Iron-Clad Dunderberg. FIG. 145.--Modern
+Iron-Clads.]
+
+It is only recently that the attempt seems to have been made to
+determine a classification of war-vessels and to plan a naval
+establishment which shall be likely to meet fully the requirements of
+the immediate future. It has hitherto been customary simply to make
+each ship a little stronger, faster, or more powerful to resist or to
+make attack than was the last. The fact that the direction of
+progress in naval science and architecture is plainly perceivable, and
+that upon its study may be based a fair estimate of the character and
+relative distribution of several classes of vessels, seems to have
+been appreciated by very few.
+
+In the year 1870 the writer proposed[99] a classification of vessels
+other than torpedo-vessels, which has since been also proposed in a
+somewhat modified form by Mr. J. Scott Russell.[100] The author then
+remarked that the increase so rapidly occurring in weight of ordnance
+and of armor, and in speed of war-vessels, would probably soon compel
+a division of the vessels of every navy into three classes of ships,
+exclusive of torpedo-vessels, one for general service in time of
+peace, the others for use only in time of war.
+
+  [99] _Journal Franklin Institute_, 1870. H. B. M. S. Monarch.
+
+  [100] London _Engineering_, 1875.
+
+"The first class may consist of unarmored vessels of moderate size,
+fair speed under steam, armed with a few tolerably heavy guns, and
+carrying full sail-power.
+
+"The second class may be vessels of great speed under steam,
+unarmored, carrying light batteries and as great spread of canvas as
+can readily be given them; very much such vessels as the Wampanoag
+class of our own navy were intended to be--calculated expressly to
+destroy the commerce of an enemy.
+
+"The third class may consist of ships carrying the heaviest possible
+armor and armament, with strongly-built bows, the most powerful
+machinery that can be given them, of large coal-carrying capacity, and
+unencumbered by sails, everything being made secondary to the one
+object of obtaining victory in contending with the most powerful of
+possible opponents. Such vessels could never go to sea singly, but
+would cruise in couples or in squadrons. It seems hardly doubtful that
+attempts to combine the qualities of all classes in a single vessel,
+as has hitherto been done, will be necessarily given up, although the
+classification indicated will certainly tend largely to restrict naval
+operations."
+
+The introduction of the stationary, the floating, and the automatic
+classes of torpedoes, and of torpedo-vessels, has now become
+accomplished, and this element, which it was predicted by Bushnell and
+by Fulton three-quarters of a century ago would at some future time
+become important in warfare, is now well recognized by all nations.
+How far it may modify future naval establishments cannot be yet
+confidently stated, but it seems sufficiently evident that the attack,
+by any navy, of stationary defenses protected by torpedoes is now
+quite a thing of the past. It may be perhaps looked upon as
+exceedingly probable that torpedo-ships of very high speed will yet
+drive all heavily-armored vessels from the ocean, thus completing the
+historic parallel between the man-in-armor of the middle ages and the
+armored man-of-war of our own time.[101]
+
+  [101] _Vide_ "Report on Machinery and Manufactures, etc., at
+  Vienna," by the author, Washington, 1875.
+
+Of these classes, the third is of most interest, as exhibiting most
+perfectly the importance and variety of the work which the
+steam-engine is made to perform. On the later of these vessels, the
+anchor is raised by a steam anchor-hoisting apparatus; the heavier
+spars and sails are handled by the aid of a steam-windlass; the helm
+is controlled by a steering-engine, and the helmsman, with his little
+finger, sets in motion a steam-engine, which adjusts the rudder with a
+power which is unimpeded by wind or sea, and with an exactness that
+could not be exceeded by the hand-steering gear of a yacht; the guns
+are loaded by steam, are elevated or depressed, and are given lateral
+training, by the same power; the turrets in which the guns are incased
+are turned, and the guns are whirled toward every point of the
+compass, in less time than is required to sponge and reload them; and
+the ship itself is driven through the water by the power of ten
+thousand horses, at a speed which is only excelled on land by that of
+the railroad-train.
+
+The British Minotaur was one of the earlier iron-clads. The great
+length and consequent difficulty of man[oe]uvring, the defect of
+speed, and the weakness of armor of these vessels have led to the
+substitution of far more effective designs in later constructions. The
+Minotaur is a four-masted screw iron-clad, 400 feet long, of 59 feet
+beam and 26-1/2 feet draught of water. Her speed at sea is about
+12-1/2 knots, and her engines develop, as a maximum, nearly 6,000
+indicated horse-power. Her heaviest armor-plates are but 6 inches in
+thickness. Her extreme length and her unbalanced rudder make it
+difficult to turn rapidly. With _eighteen men at the steering-wheel_
+and sixty others on the tackle, the ship, on one occasion, was 7-1/2
+minutes in turning completely around. These long iron-clads were
+succeeded by the shorter vessels designed by Mr. E. J. Reed, of which
+the first, the Bellerophon, was of 4,246 tons burden, 300 feet long by
+56 feet beam, and 24-1/2 feet draught, of the 14-knot speed, with
+4,600 horse-power; and having the "balanced rudder" used many years
+earlier in the United States by Robert L. Stevens,[102] it can turn in
+four minutes with eight men at the wheel. The cost of construction was
+some $600,000 less than that of the Minotaur. A still later vessel,
+the Monarch, was constructed on a system quite similar to that known
+in the United States as the Monitor type, or as a turreted iron-clad.
+This vessel is 330 feet long, 57-1/2 feet wide, and 36 feet deep,
+drawing 24-1/2 feet of water. The total weight of ship and contents is
+over 8,000 tons, and the engines are of over 8,500 horse-power. The
+armor is 6 and 7 inches thick on the hull, and 8 inches on the two
+turrets, over a heavy teak backing. The turrets contain each two
+12-inch rifled guns, weighing 25 tons each, and, with a charge of 70
+pounds of powder, throwing a shot of 600 pounds weight with a velocity
+of 1,200 feet per second, and giving it a _vis viva_ equivalent to the
+raising of over 6,100 tons one foot high, and equal to the work of
+penetrating an iron plate 13-1/2 inches thick. This immense vessel is
+driven by a pair of "single-cylinder" engines having steam-cylinders
+_ten feet_ in diameter and of 4-1/2 feet stroke of piston, driving a
+two-bladed Griffith screw of 23-1/2 feet diameter and 26-1/2 feet
+pitch, 65 revolutions, at the maximum speed of 14.9 knots, or about
+17-1/2 miles, an hour. To drive these powerful engines, boilers having
+an aggregate of about 25,000 square feet (or more than a half-acre) of
+heating-surface are required, with 900 square feet of grate-surface.
+The refrigerating surface in the condensers has an area of 16,500
+square feet--over one-third of an acre. The cost of these engines and
+boilers was £66,500.
+
+  [102] Still in use on the Hoboken ferry-boats.
+
+Were all this vast steam-power developed, giving the vessel a speed of
+15 knots, the ship, if used as a "ram," would strike an enemy at rest
+with the tremendous "energy" of 48,000 foot-tons--equal to the shock
+of the projectiles of eight or nine such guns as are carried by the
+iron-clad itself, simultaneously discharged upon one spot.
+
+But even this great vessel is less formidable than later vessels. One
+of the latter, the Inflexible, is a shorter but wider and deeper ship
+than the Monarch, measuring 320 feet long, 75 feet beam, and 25
+draught, displacing over 10,000 tons. The great rifles carried by this
+vessel weigh 81 tons each, throwing shot weighing a half-ton from
+behind iron-plating two feet in thickness. The steam-engines are of
+about the same power as those of the Monarch, and give this enormous
+hull a speed of 14 knots an hour.
+
+The navy of the United States does not to-day possess iron-clads of
+power even approximating that of either of several classes of British
+and other foreign naval vessels.
+
+The largest vessel of any class yet constructed is the Great Eastern
+(Fig. 146), begun in 1854 and completed in 1859, by J. Scott Russell,
+on the Thames, England. This ship is 680 feet long, 83 feet wide, 58
+feet deep, 28 feet draught, and of 24,000 tons measurement. There are
+four paddle and four screw engines, the former having steam-cylinders
+74 inches in diameter, with 14 feet stroke, the latter 84 inches in
+diameter and 4 feet stroke. They are collectively of 10,000 actual
+horse-power. The paddle-wheels are 56 feet in diameter, the screw 24
+feet. The steam-boilers supplying the paddle-engines have 44,000
+square feet (more than an acre) of heating-surface. The boilers
+supplying the screw-engines are still larger. At 30 feet draught, this
+great vessel displaces 27,000 tons. The engines were designed to
+develop 10,000 horse-power, driving the ship at the rate of 16-1/2
+statute miles an hour.
+
+[Illustration: FIG. 146.--The Great Eastern.]
+
+The figures quoted in the descriptions of these great steamships do
+not enable the non-professional reader to form a conception of the
+wonderful power which is concentrated within so small a space as is
+occupied by their steam-machinery. The "horse-power" of the engines is
+that determined by James Watt as the maximum obtainable for eight
+hours a day from the strongest London draught-horses. The ordinary
+average draught-horse would hardly be able to exert two-thirds as much
+during the eight hours' steady work of a working-day. The working-day
+of the steam-engine, on the other hand, is twenty-four hours in
+length.
+
+[Illustration: FIG. 147.--The Great Eastern at Sea.]
+
+The work of the 10,000 horse-power engines of the Great Eastern could
+be barely equaled by the efforts of 15,000 horses; but to continue
+their work uninterruptedly, day in and day out, for weeks together, as
+when done by steam, would require at least three relays, or 45,000
+horses. Such a stud would weigh 25,000 tons, and if harnessed "tandem"
+would extend thirty miles. It is only by such a comparison that the
+mind can begin to comprehend the utter impossibility of accomplishing
+by means of animal power the work now done for the world by steam.
+The cost of the greater power is but about one-tenth that of
+horse-power, and by its means tasks are accomplished with ease which
+are absolutely impossible of accomplishment by animal power.
+
+It is estimated that the total steam-power of the world is about
+15,000,000 horse-power, and that, were horses actually employed to do
+the work which these engines would be capable of doing were they kept
+constantly in operation, the number required would exceed 60,000,000.
+
+Thus, from the small beginnings of the Comte d'Auxiron and the Marquis
+de Jouffroy in France, of Symmington in Great Britain, and of Henry,
+Rumsey, and Fitch, and of Fulton and Stevens, in the United States,
+steam-navigation has grown into a great and inestimable aid and
+blessing to mankind.
+
+We to-day cross the ocean with less risk, and transport ourselves and
+our goods at as little cost in either time or money as, at the
+beginning of the century, our parents experienced in traveling
+one-tenth the distance.
+
+It is largely in consequence of this ingenious application of a power
+that reminds one of the fabled genii of Eastern romance, that the
+mechanic and the laborer of to-day enjoy comforts and luxuries that
+were denied to wealth, and to royalty itself, a century ago.
+
+The magnitude of our modern steamships excites the wonder and
+admiration of even the people of our own time; and there is certainly
+no creation of art that can be grander in appearance than a
+transatlantic steamer a hundred and fifty yards in length, and
+weighing, with her stores, five or six thousand tons, as she starts on
+her voyage, moved by engines equal in power to the united strength of
+thousands of horses; none can more fully awaken a feeling of awe than
+an immense structure like the great modern iron-clads (Fig. 145),
+vessels having a total weight of 8,000 to 10,000 tons, and propelled
+by steam-engines of as many horse-power, carrying guns whose shot
+penetrate solid iron 20 inches thick, and having a power of impact,
+when steaming at moderate speed, sufficient to raise 35,000 tons a
+foot high.
+
+Far more huge than the Monarch among the iron-clads even is that
+prematurely-built monster, the Great Eastern (Fig. 147), already
+described, an eighth of a mile long, and with steam doing the work of
+a stud of 45,000 horses.
+
+Thus we are to-day witnessing the literal fulfillment of the
+predictions of Oliver Evans and of John Stevens, and almost that
+contained in the couplets written by the poet Darwin, who, more than a
+century ago, before even the earliest of Watt's improvements had
+become generally known, sang:
+
+    "Soon shall thy arm, unconquered Steam, afar
+    Drag the slow barge, or drive the rapid car;
+    Or, on wide-waving wings expanded, bear
+    The flying chariot through the fields of air."
+
+[Illustration]
+
+
+
+
+CHAPTER VII.
+
+_THE PHILOSOPHY OF THE STEAM-ENGINE._
+
+THE HISTORY OF ITS GROWTH; ENERGETICS AND THERMO-DYNAMICS.
+
+  "Of all the features which characterize this progressive economical
+  movement of civilized nations, that which first excites attention,
+  through its intimate connection with the phenomena of production, is
+  the perpetual and, so far as human foresight can extend, the
+  unlimited growth of man's power over Nature. Our knowledge of the
+  properties and laws of physical objects shows no sign of approaching
+  its ultimate boundaries; it is advancing more rapidly, and in a
+  greater number of directions at once, than in any previous age or
+  generation, and affording such frequent glimpses of unexplored
+  fields beyond as to justify the belief that our acquaintance with
+  Nature is still almost in its infancy."--MILL.
+
+
+The growth of the philosophy of the steam-engine presents as
+interesting a study as that of the successive changes which have
+occurred in its mechanism.
+
+In the operation of the steam-engine we find illustrated many of the
+most important principles and facts which constitute the physical
+sciences. The steam-engine is an exceedingly ingenious, but,
+unfortunately, still very imperfect, machine for transforming the
+heat-energy obtained by the chemical combination of a combustible with
+the supporter of combustion into mechanical energy. But the original
+source of all this energy is found far back of its first appearance in
+the steam-boiler. It had its origin at the beginning, when all Nature
+came into existence. After the solar system had been formed from the
+nebulous chaos of creation, the glowing mass which is now called the
+sun was the depository of a vast store of heat-energy, which was
+thence radiated into space and showered upon the attendant worlds in
+inconceivable quantity and with unmeasured intensity. During the past
+life of the globe, the heat-energy received from the sun upon the
+earth's surface was partly expended in the production of great
+forests, and the storage, in the trunks, branches, and leaves of the
+trees of which they were composed, of an immense quantity of carbon,
+which had previously existed in the atmosphere, combined with oxygen,
+as carbonic acid. The great geological changes which buried these
+forests under superincumbent strata of rock and earth resulted in the
+formation of coal-beds, and the storage, during many succeeding ages,
+of a vast amount of carbon, of which the affinity for oxygen remained
+unsatisfied until finally uncovered by the hand of man. Thus we owe to
+the heat and light of the sun, as was pointed out by George
+Stephenson, the incalculable store of potential energy upon which the
+human race is so dependent for life and all its necessaries, comforts,
+and luxuries.
+
+This coal, thrown upon the grate in the steam-boiler, takes fire, and,
+uniting again with the oxygen, sets free heat in precisely the same
+quantity that it was received from the sun and appropriated during the
+growth of the tree. The actual energy thus rendered available is
+transferred, by conduction and radiation, to the water in the
+steam-boiler, converts it into steam, and its mechanical effect is
+seen in the expansion of the liquid into vapor against the
+superincumbent pressure. Transferred from the boiler to the engine,
+the steam is there permitted to expand, doing work, and the
+heat-energy with which it is charged becomes partly converted into
+mechanical energy, and is applied to useful work in the mill or to
+driving the locomotive or the steamboat.
+
+Thus we may trace the store of energy received from the sun and
+contained in our coal through its several changes until it is finally
+set at work; and we might go still further and observe how, in each
+case, it is again usually re-transformed and again set free as
+heat-energy.
+
+The transformation which takes place in the furnace is a chemical
+change; the transfer of heat to the water and the subsequent phenomena
+accompanying its passage through the engine are physical changes, some
+of which require for their investigation abstruse mathematical
+operations. A thorough comprehension of the principles governing the
+operation of the steam-engine, therefore, can only be attained after
+studying the phenomena of physical science with sufficient minuteness
+and accuracy to be able to express with precision the laws of which
+those sciences are constituted. The study of the philosophy of the
+steam-engine involves the study of chemistry and physics, and of the
+new science of energetics, of which the now well-grown science of
+thermo-dynamics is a branch. This sketch of the growth of the
+steam-engine may, therefore, be very properly concluded by an outline
+of the growth of the several sciences which together make up its
+philosophy, and especially of the science of thermo-dynamics, which is
+peculiarly the science of the steam-engine and of the other
+heat-engines.
+
+These sciences, like the steam-engine itself, have an origin which
+antedates the commencement of the Christian era; but they grew with an
+almost imperceptible growth for many centuries, and finally, only a
+century ago, started onward suddenly and rapidly, and their progress
+has never since been checked. They are now fully-developed and
+well-established systems of natural philosophy. Yet, like that of the
+steam-engine and of its companion heat-engines, their growth has by no
+means ceased; and, while the student of science cannot do more than
+indicate the direction of their progress, he can readily believe that
+the beginning of the end is not yet reached in their movement toward
+completeness, either in the determination of facts or in the
+codification of their laws.
+
+When Hero lived at Alexandria, the great "Museum" was a most important
+centre, about which gathered the teachers of all then known
+philosophies and of all the then recognized but unformed sciences, as
+well as of all those technical branches of study which had already
+been so far developed as to be capable of being systematically taught.
+Astronomical observations had been made regularly and uninterruptedly
+by the Chaldean astrologers for two thousand years, and records
+extending back many centuries had been secured at Babylon by
+Calisthenes and given to Aristotle, the father of our modern
+scientific method. Ptolemy had found ready to his hand the records of
+Chaldean observers of eclipses extending back nearly 650 years, and
+marvelously accurate.[103]
+
+  [103] Their estimate of the length of the Saros, or cycle of
+  eclipses--over 19 years--was "within 19-1/2 minutes of the
+  truth."--DRAPER.
+
+A rude method of printing with an engraved roller on plastic clay,
+afterward baked, thus making up ceramic libraries, was practised long
+previous to this time; and in the alcoves in which Hero worked were
+many of these books of clay.
+
+This great Library and Museum of Alexandria was founded three
+centuries before the birth of Christ, by Ptolemy Soter, who
+established as his capital that great Egyptian city when the death of
+his brother, the youthful but famous conqueror whose name he gave it,
+placed him upon the throne of the colossal successor of the then
+fallen Persian Empire. The city itself, embellished with every
+ornament and provided with every luxury that the wealth of a conquered
+world or the skill, taste, and ingenuity of the Greek painters,
+sculptors, architects, and engineers could provide, was full of
+wonders; it was a wonder in itself. This rich, populous, and
+magnificent city was the metropolis of the then civilized world.
+Trade, commerce, manufactures, and the fine arts were all represented
+in this splendid exchange, and learning found its most acceptable
+home and noblest field within the walls of Ptolemy's Museum; its
+disciples found themselves welcomed and protected by its founder and
+his successors, Philadelphus and the later Ptolemies.
+
+The Alexandrian Museum was founded with the declared object of
+collecting all written works of authority, of promoting the study of
+literature and art, and of stimulating and assisting experimental and
+mathematical scientific investigation and research. The founders of
+modern libraries, colleges, and technical schools have their prototype
+in intelligence, public spirit, and liberality, in the first of the
+Ptolemies, who not only spent an immense sum in establishing this
+great institution, but spared no expense in sustaining it. Agents were
+sent out into all parts of the world, purchasing books. A large staff
+of scribes was maintained at the museum, whose duty it was to multiply
+copies of valuable works, and to copy for the library such works as
+could not be purchased.
+
+The faculty of the museum was as carefully organized as was the plan
+of its administration. The four principal faculties of astronomy,
+literature, mathematics, and medicine were subdivided into sections
+devoted to the several branches of each department. The collections of
+the museum were as complete as the teachers of the undeveloped
+sciences of the time could make them. Lectures were given in all
+branches of study, and the number of students was sometimes as great
+as twelve or thirteen thousand. The number of books which were
+collected here, when the barbarian leaders of the Roman troops under
+Cæsar burned the greater part of it, was stated to be 700,000. Of
+these, 400,000 were within the museum itself, and were all destroyed;
+the rest were in the temple of Serapis, and, for the time, escaped
+destruction.
+
+The greatest of all the great men who lived at Alexandria at the time
+of the establishment of the museum was Aristotle, the teacher of
+Alexander and the friend of Ptolemy. It is to Aristotle that we owe
+the systematization of the philosophical ideas of Plato and the
+creation of the inductive method, in which has originated all modern
+science. It is to the learned men of Alexandria that we are indebted
+for so effective an application of the Aristotelian philosophy that
+all the then known sciences were given form, and were so thoroughly
+established that the work of modern science has been purely one of
+development.
+
+The inductive method, which built up all the older sciences, and which
+has created all those of recent development, consists, first, in the
+discovery and quantitative determination of facts; secondly, when a
+sufficient number of facts have been thus observed and defined, in the
+grouping of those facts, and the detection, by a study of their mutual
+relations, of the natural laws which give rise to or regulate them.
+This simple method is that--and the only--method by which science
+advances. By this method, and by it only, do we acquire connected and
+systematic knowledge of all the phenomena of Nature of which the
+physical sciences are cognizant. It is only by the application of this
+Aristotelian method and philosophy that we can hope to acquire exact
+scientific knowledge of existing phenomena, or to become able to
+anticipate the phenomena which are to distinguish the future. The
+Aristotelian method of observing facts, and of inductive reasoning
+with those facts as a basis, has taught the chemist the properties of
+the known elementary substances and their characteristic behavior
+under ascertained conditions, and has taught him the laws of
+combination and the effects of their union, enabling him to predict
+the changes and the phenomena, chemical and physical, which inevitably
+follow their contact under any specified set of conditions.
+
+It is this process which has enabled the physicist to ascertain the
+methods of molecular motion which give us light, heat, or electricity,
+and the range of action and the laws which govern the transfer of
+energy from one of these modes of motion to another. It was this
+method of study which enabled James Watt to detect and to remedy the
+defects of the Newcomen engine, and it is by the Aristotelian
+philosophy that the engineer of to-day is taught to construct the
+modern steamship, and to predict, before the keel is laid or a blow
+struck in the workshop or the ship-yard, what will be the weight of
+the vessel, its cargo-carrying capacity, the necessary size and power
+of its engines, the quantity of coal which they will require per day
+while crossing the ocean, the depth at which the great hull will float
+in the water, and the exact speed that the vessel will attain when the
+engines are exerting their thousand or their ten thousand horse-power.
+
+It was at Alexandria that this mighty philosophy was first given a
+field in which to work effectively. Here Ptolemy studied astronomy and
+"natural philosophy;" Archimedes applied himself to the studies which
+attract the mathematician and engineer; Euclid taught his royal pupil
+those elements of geometry which have remained standard twenty-two
+centuries; Eratosthenes and Hipparchus studied and taught astronomy,
+and inaugurated the existing system of quantitative investigation,
+proving the spherical form of the earth; and Ctesibius and Hero
+studied pneumatics and experimented with the germs of the steam-engine
+and of less important machines.
+
+When, seven centuries later, the destruction of this splendid
+institution was signalized by the death of that brilliant scholar and
+heathen teacher of philosophy, Hypatia, at the hands of the more
+heathenish fanatics who tore her in pieces at the foot of the cross,
+and by the dispersion of the library left by Cæsar's soldiers in the
+Serapeum, a true philosophy had been created, and the inductive method
+was destined to live and to overcome every obstacle in the path of
+enlightenment and civilization. The fall of the Alexandrian Museum,
+sad as was the event, could not destroy the new philosophical method.
+Its fruits ripened slowly but surely, and we are to-day gathering a
+plentiful harvest.
+
+Science, literature, and the arts, all remained dormant for several
+centuries after the catastrophe which deprived them of the light in
+which they had flourished so many centuries. The armies of the caliphs
+made complete the shameful work of destruction begun by the armies of
+Cæsar, and the Alexandrian Library, partly destroyed by the Romans,
+was completely dispersed by the Patriarchs and their ignorant and
+fanatical followers; and finally all the scattered remnants were
+burned by the Saracens. But when the thirst for conquest had become
+satiated or appeased, the followers of the caliphs turned their
+attention to intellectual pursuits, and the ninth century of the
+Christian era saw once more such a collection of philosophical
+writings, collected at Bagdad, as could only be gathered by the power
+and wealth of the later conquerors of the world. Philosophy once again
+resumed its empire, and another race commenced the study of the
+mathematics of India and of Greece, the astronomy of Chaldea, and of
+all the sciences which originated in Greece and in Egypt. By the
+conquest of Spain by the Saracens, the new civilization was imported
+into Western Europe and libraries were gathered together under the
+Moorish rulers, one of which numbered more than a half-million
+volumes. Wherever Saracen armies had extended Mohammedan rule,
+schools and colleges, libraries and collections of philosophical
+apparatus, were scattered in strange profusion; and students,
+teachers, philosophers, of all--the speculative as well as the
+Aristotelian--schools, gathered together at these intellectual
+ganglia, as enthusiastic in their work as were their Alexandrian
+predecessors. The endowment of colleges, that truest gauge of the
+intelligence of the wealthy classes of any community, became as
+common--perhaps more so--as at the present time, and provision was
+made for the education of rich and poor alike. The mathematical
+sciences, and the wonderful and beautiful phenomena which--but a
+thousand years later--were afterward grouped into a science and called
+chemistry, were especially attractive to the Arabian scholars, and
+technical applications of discovered facts and laws assisted in a
+wonderfully rapid development of arts and manufactures.
+
+When, a thousand years after Christ, the centre of intellectual
+activity and of material civilization had drifted westward into
+Andalusia, the foundation of every modern physical science except that
+now just taking shape--the all-grasping science of energetics--had
+been laid with experimentally derived facts; and in mathematics there
+had been erected a symmetrical and elegant superstructure. Even that
+underlying principle of all the sciences, the principle of the
+persistence of energy, had been, perhaps unwittingly, enunciated.
+
+Distinguished historians have shown how the progress of civilization
+in Europe resulted in the creation, during the middle ages, of the now
+great middle class, which, holding the control of political power,
+governs every civilized nation, and has come into power so gradually
+that it was only after centuries that its influence was seen and felt.
+This, which Buckle[104] calls the intellectual class, first became
+active, independently of the military and of the clergy, in the
+fourteenth century. In the two succeeding centuries this class gained
+power and influence; and in the seventeenth century we find a
+magnificent advance in all branches of science, literature, and art,
+marking the complete emancipation of the intellect from the artificial
+conditions which had so long repressed its every effort at
+advancement.
+
+  [104] "History of Civilization in England," vol. i., p. 208. London,
+  1868.
+
+Another great social revolution thus occurred, following another
+period of centuries of intellectual stagnation. The Saracen invaders
+were driven from Europe; the Crusaders invaded Palestine, in the vain
+effort to recover from the hands of the infidels the Holy Sepulchre
+and the Holy Land; and intestine broils and inter-state conflicts, as
+well as these greater social movements, withdrew the minds of men once
+more from the arts of peace and the pursuits of scholars. It is not,
+then, until the beginning of the seventeenth century--the time of
+Galileo and of Newton--that we find the nations of Europe sufficiently
+quiet and secure to permit general attention to intellectual
+vocations, although it was a half-century earlier (1543) that
+Copernicus left to the world that legacy which revolutionized the
+theories of the astronomers and established as correct the hypothesis
+which made the sun the centre of the solar system.
+
+Galileo now began to overturn the speculations of the deductive
+philosophers, and to proclaim the still disputed principle that the
+book of Nature is a trustworthy commentary in the study of theological
+and revealed truths, so far as they affect or are affected by science;
+he suffered martyrdom when he proclaimed the fact that God's laws, as
+they now stand, had been instituted without deference to the
+preconceived notions of the most ignorant of men. Bruno had a few
+years earlier (1600) been burned at the stake for a similar offense.
+
+Galileo was perhaps the first, too, to combine invariably in
+application the idea of Plato, the philosophy of Aristotle, and the
+methods of modern experimentation, to form the now universal
+scientific method of experimental philosophy. He showed plainly how
+the grouping of ascertained facts, in natural sequence, leads to the
+revelation of the law of that sequence, and indicated the existence of
+a principle which is now known as the law of continuity--the law that
+in all the operations of Nature there is to be seen an unbroken chain
+of effect leading from the present back into a known or an unknown
+past, toward a cause which may or may not be determinable by science
+or known to history.
+
+Galileo, the Italian, was worthily matched by Newton, the prince of
+English philosophers. The science of theoretical mechanics was hardly
+beginning to assume the position which it was afterward given among
+the sciences; and the grand work of collating facts already
+ascertained, and of definitely stating principles which had previously
+been vaguely recognized, was splendidly done by Newton. The needs of
+physical astronomy urged this work upon him.
+
+Da Vinci had, in the latter half of the fifteenth century, summarized
+as much of the statics of mechanical philosophy as had, up to his
+time, been given shape; he also rewrote and added very much to what
+was known on the subject of friction, and enunciated its laws. He had
+evidently a good idea of the principle of "virtual velocities," that
+simple case of equivalence of work, in a connected system, which has
+done such excellent service since; and with his mechanical philosophy
+this versatile engineer and artist curiously mingled much of physical
+science. Then Stevinus, the "brave engineer of Bruges," a hundred
+years later (1586), alternating office and field work, somewhat after
+the manner of the engineer of to-day, wrote a treatise on mechanics,
+which showed the value of practical experience and judgment in even
+scientific work. And thus the path had been cleared for Newton.
+
+Meantime, also, Kepler had hit upon the true relations of the
+distances of the planets and their periodic times, after spending half
+a generation in blindly groping for them, thus furnishing those great
+landmarks of fact in the mechanics of astronomy; and Galileo had
+enunciated the laws of motion. Thus the foundation of the science of
+dynamics, as distinguished from statics, was laid, and the beginning
+was made of that later science of energetics, of which the philosophy
+of the steam-engine is so largely constituted.
+
+Hooke, Huyghens, and others, had already seen some of the principal
+consequences of these laws; but it remained for Newton to enunciate
+them with the precision of a true mathematician, and to base upon them
+a system of dynamical laws, which, complemented by his announcement of
+the existence of the force of gravitation, and his statement of its
+laws, gave a firm basis for all that the astronomer has since done in
+those quantitative determinations of size, weight, and distance, and
+of the movements of the heavenly bodies, which compel the wonder and
+admiration of mankind.
+
+The Arabians and Greeks had noticed that the direction taken by a body
+falling under the action of gravitation was directly toward the centre
+of the earth, wherever its fall might occur; Galileo had shown, by his
+experiments at Pisa, that the velocity of fall, second after second,
+varied as the numbers 1, 3, 5, 7, 9, etc., and that the distances
+varied as the squares of the total periods of time during which the
+body was falling, and that it was, in British feet, very nearly
+sixteen times the square of that time in seconds. Kepler had proved
+that the movements of the heavenly bodies were just such as would
+occur under the action of central attractive forces and of centrifugal
+force.
+
+Putting all these things together, Newton was led to believe that
+there existed a "force of gravity," due to the attraction, by the
+great mass of the earth, of its own particles and of neighboring
+bodies, like the moon, of which force the influence extended as far,
+at least, as the latter. He calculated the motion of the earth's
+satellite, on the assumption that his theory and the then accepted
+measurements of the earth's dimensions were correct, and obtained a
+roughly approximate result. Later, in 1679, he revised his
+calculations, using Picard's more accurate determination of the
+dimensions of the earth, and obtained a result which precisely tallied
+with careful measurements, made by the astronomers, of the moon's
+motion.
+
+The science of mechanics had now, with the publication of Newton's
+"Principia," become thoroughly consistent and logically complete, so
+far as was possible without a knowledge of the principles of
+energetics; and Newton's enunciations of the laws of motion, concise
+and absolutely perfect as they still seem, were the basis of the whole
+science of dynamics, as applied to bodies moving freely under the
+action of applied forces, either constant or variable. They are as
+perfect a basis for that science as are the primary principles of
+geometry for the whole beautiful structure which is built up on them.
+
+The three perfect qualitative expressions of dynamical law are:
+
+1. Every free body continues in the state in which it may be, whether
+of rest or of rectilinear uniform motion, until compelled to deviate
+from that state by impressed forces.
+
+2. Change of motion is proportional to the force impressed, and in the
+direction of the right line in which that force acts.
+
+3. Action is always opposed by reaction; action and reaction are
+equal, and in directly contrary directions.
+
+We may add to these principles a definition of a force, which is
+equally and absolutely complete:
+
+_Force_ is that which produces, or tends to produce, motion, or change
+of motion, in bodies. It is measured statically by the weight that
+will counterpoise it, or by the pressure which it will produce, and
+dynamically by the velocity which it will produce, acting in the unit
+of time on the unit of mass.
+
+The quantitative determinations of dynamic effects of forces are
+always readily made when it is remembered that the effect of a force
+equal to its own weight, when the body is free to move, is to produce
+in one second a velocity of 32.2 feet per second, which quantity is
+the unit of dynamic measurement.
+
+_Work_ is the product of the resistance met in any instance of the
+exertion of a force, into the distance through which that force
+overcomes the resistance.
+
+_Energy_ is the work which a body is capable of doing, by its weight
+or inertia, under given conditions. The energy of a falling body, or
+of a flying shot, is about 1/64 its weight multiplied by the square of
+its velocity, or, which is the same thing, the product of its weight
+into the height of fall or height due its velocity. These principles
+and definitions, with the long-settled definitions of the primary
+ideas of space and time, were all that were needed to lead the way to
+that grandest of all physical generalizations, the doctrine of the
+persistence or conservation of all energy, and to its corollary
+declaring the equivalence of all forms of energy, and also to the
+experimental demonstration of the transformability of energy from one
+mode of existence to another, and its universal existence in the
+various modes of motion of bodies and of their molecules.
+
+Experimental physical science had hardly become acknowledged as the
+only and the proper method of acquiring knowledge of natural phenomena
+at the time of Newton; but it soon became a generally accepted
+principle. In physics, Gilbert had made valuable investigations before
+Newton, and Galileo's experiments at Pisa had been examples of
+similarly useful research. In chemistry, it was only when, a century
+later, Lavoisier showed by his splendid example what could be done by
+the skillful and intelligent use of quantitative measurements, and
+made the balance the chemist's most important tool, that a science was
+formed comprehending all the facts and laws of chemical change and
+molecular combination. We have already seen how astronomy and
+mathematics together led philosophers to the creation and the study of
+what finally became the science of mechanics, when experiment and
+observation were finally brought to their aid. We can now see how, in
+all these physical sciences, four primitive ideas are comprehended:
+matter, force, motion, and space--which latter two terms include all
+relations of position.
+
+Based on these notions, the science of mechanics comprehends four
+sections, which are of general application in the study of all
+physical phenomena. These are:
+
+_Statics_, which treats of the action and effect of forces.
+
+_Kinematics_, which treats of relations of motion simply.
+
+_Dynamics_, or kinetics, which treats of simple motion as an effect of
+the action of forces.
+
+_Energetics_, which treats of modifications of energy under the action
+of forces, and of its transformation from one mode of manifestation to
+another, and from one body to another.
+
+Under the latter of these four divisions of mechanical philosophy is
+comprehended that latest of the minor sciences, of which the
+heat-engines, and especially the steam-engine, illustrate the most
+important applications--_Thermo-dynamics_. This science is simply a
+wider generalization of principles which, as we have seen, have been
+established one at a time, and by philosophers widely separated both
+geographically and historically, by both space and time, and which
+have been slowly aggregated to form one after another of the sciences,
+and out of which, as we now are beginning to see, we are slowly
+evolving wider generalizations, and thus tending toward a condition of
+scientific knowledge which renders more and more probable the truth of
+Cicero's declaration: "One eternal and immutable law embraces all
+things and all times." At the basis of the whole science of energetics
+lies a principle which was enunciated before Science had a birthplace
+or a name:
+
+_All that exists, whether matter or force, and in whatever form, is
+indestructible, except by the Infinite Power which has created it._
+
+That matter is indestructible by finite power became admitted as soon
+as the chemists, led by their great teacher Lavoisier, began to apply
+the balance, and were thus able to show that in all chemical change
+there occurs only a modification of form or of combination of
+elements, and no loss of matter ever takes place. The "persistence" of
+energy was a later discovery, consequent largely upon the experimental
+determination of the convertibility of heat-energy into other forms
+and into mechanical work, for which we are indebted to Rumford and
+Davy, and to the determination of the quantivalence anticipated by
+Newton, shown and calculated approximately by Colding and Mayer, and
+measured with great probable accuracy by Joule.
+
+[Illustration: Benjamin Thompson, Count Rumford.]
+
+The great fact of the conservation of energy was loosely stated by
+Newton, who asserted that the work of friction and the _vis viva_ of
+the system or body arrested by friction were equivalent. In 1798,
+Benjamin Thompson, Count Rumford, an American who was then in the
+Bavarian service, presented a paper[105] to the Royal Society of Great
+Britain, in which he stated the results of an experiment which he had
+recently made, proving the immateriality of heat and the
+transformation of mechanical into heat energy. This paper is of very
+great historical interest, as the now accepted doctrine of the
+persistence of energy is a generalization which arose out of a series
+of investigations, the most important of which are those which
+resulted in the determination of the existence of a definite
+quantivalent relation between these two forms of energy and a
+measurement of its value, now known as the "mechanical equivalent of
+heat." His experiment consisted in the determination of the quantity
+of heat produced by the boring of a cannon at the arsenal at Munich.
+
+  [105] "Philosophical Transactions," 1798.
+
+Rumford, after showing that this heat could not have been derived from
+any of the surrounding objects, or by compression of the materials
+employed or acted upon, says: "It appears to me extremely difficult,
+if not impossible, to form any distinct idea of anything capable of
+being excited and communicated in the manner that heat was excited and
+communicated in these experiments, except it be motion."[106] He then
+goes on to urge a zealous and persistent investigation of the laws
+which govern this motion. He estimates the heat produced by a power
+which he states could easily be exerted by one horse, and makes it
+equal to the "combustion of nine wax candles, each three-quarters of
+an inch in diameter," and equivalent to the elevation of "25.68 pounds
+of ice-cold water" to the boiling-point, or 4,784.4 heat-units.[107]
+The time was stated at "150 minutes." Taking the actual power of
+Rumford's Bavarian "one horse" as the most probable figure, 25,000
+pounds raised one foot high per minute,[108] this gives the
+"mechanical equivalent" of the foot-pound as 783.8 heat-units,
+differing but 1.5 per cent. from the now accepted value.
+
+  [106] This idea was not by any means original with Rumford. Bacon
+  seems to have had the same idea; and Locke says, explicitly enough:
+  "Heat is a very brisk agitation of the insensible parts of the
+  object ... so that what in our sensation is heat, in the object is
+  nothing but motion."
+
+  [107] The British heat-unit is the quantity of heat required to heat
+  one pound of water 1° Fahr. from the temperature of maximum density.
+
+  [108] Rankine gives 25,920 foot-pounds per minute--or 432 per
+  second--for the average draught-horse in Great Britain, which is
+  probably too high for Bavaria. The engineer's "horse-power"--33,000
+  foot-pounds per minute--is far in excess of the average power of
+  even a good draught-horse, which latter is sometimes taken as
+  two-thirds the former.
+
+Had Rumford been able to eliminate all losses of heat by evaporation,
+radiation, and conduction, to which losses he refers, and to measure
+the power exerted with accuracy, the approximation would have been
+still closer. Rumford thus made the experimental discovery of the real
+nature of heat, proving it to be a form of energy, and, publishing
+the fact a half-century before the now standard determinations were
+made, gave us a very close approximation to the value of the
+heat-equivalent. Rumford also observed that the heat generated was
+"exactly proportional to the force with which the two surfaces are
+pressed together, and to the rapidity of the friction," which is a
+simple statement of equivalence between the quantity of work done, or
+energy expended, and the quantity of heat produced. This was the first
+great step toward the formation of a Science of Thermo-dynamics.
+Rumford's work was the corner-stone of the science.
+
+Sir Humphry Davy, a little later (1799), published the details of an
+experiment which conclusively confirmed these deductions from
+Rumford's work. He rubbed two pieces of ice together, and found that
+they were melted by the friction so produced. He thereupon concluded:
+"It is evident that ice by friction is converted into water....
+Friction, consequently, does not diminish the capacity of bodies for
+heat."
+
+Bacon and Newton, and Hooke and Boyle, seem to have anticipated--long
+before Rumford's time--all later philosophers, in admitting the
+probable correctness of that modern dynamical, or vibratory, theory of
+heat which considers it a mode of motion; but Davy, in 1812, for the
+first time, stated plainly and precisely the real nature of heat,
+saying: "The immediate cause of the phenomenon of heat, then, is
+motion, and the laws of its communication are precisely the same as
+the laws of the communication of motion." The basis of this opinion
+was the same that had previously been noted by Rumford.
+
+So much having been determined, it became at once evident that the
+determination of the exact value of the mechanical equivalent of heat
+was simply a matter of experiment; and during the succeeding
+generation this determination was made, with greater or less
+exactness, by several distinguished men. It was also equally evident
+that the laws governing the new science of thermo-dynamics could be
+mathematically expressed.
+
+Fourier had, before the date last given, applied mathematical analysis
+in the solution of problems relating to the transfer of heat without
+transformation, and his "Théorie de la Chaleur" contained an
+exceedingly beautiful treatment of the subject. Sadi Carnot, twelve
+years later (1824), published his "Réflexions sur la Puissance Motrice
+du Feu," in which he made a first attempt to express the principles
+involved in the application of heat to the production of mechanical
+effect. Starting with the axiom that a body which, having passed
+through a series of conditions modifying its temperature, is returned
+to "its primitive physical state as to density, temperature, and
+molecular constitution," must contain the same quantity of heat which
+it had contained originally, he shows that the efficiency of
+heat-engines is to be determined by carrying the working fluid through
+a complete cycle, beginning and ending with the same set of
+conditions. Carnot had not then accepted the vibratory theory of heat,
+and consequently was led into some errors; but, as will be seen
+hereafter, the idea just expressed is one of the most important
+details of a theory of the steam-engine.
+
+Seguin, who has already been mentioned as one of the first to use the
+fire-tubular boiler for locomotive engines, published in 1839 a work,
+"Sur l'Influence des Chemins de Fer," in which he gave the requisite
+data for a rough determination of the value of the mechanical
+equivalent of heat, although he does not himself deduce that value.
+
+Dr. Julius R. Mayer, three years later (1842), published the results
+of a very ingenious and quite closely approximate calculation of the
+heat-equivalent, basing his estimate upon the work necessary to
+compress air, and on the specific heats of the gas, the idea being
+that the work of compression is the equivalent of the heat generated.
+Seguin had taken the converse operation, taking the loss of heat of
+expanding steam as the equivalent of the work done by the steam while
+expanding. The latter also was the first to point out the fact,
+afterward experimentally proved by Hirn, that the fluid exhausted from
+an engine should heat the water of condensation less than would the
+same fluid when originally taken into the engine.
+
+A Danish engineer, Colding, at about the same time (1843), published
+the results of experiments made to determine the same quantity; but
+the best and most extended work, and that which is now almost
+universally accepted as standard, was done by a British investigator.
+
+James Prescott Joule commenced the experimental investigations which
+have made him famous at some time previous to 1843, at which date he
+published, in the _Philosophical Magazine_, his earliest method. His
+first determination gave 770 foot-pounds. During the succeeding five
+or six years Joule repeated his work, adopting a considerable variety
+of methods, and obtaining very variable results. One method was to
+determine the heat produced by forcing air through tubes; another, and
+his usual plan, was to turn a paddle-wheel by a definite power in a
+known weight of water. He finally, in 1849, concluded these
+researches.
+
+[Illustration: James Prescott Joule.]
+
+The method of calculating the mechanical equivalent of heat which was
+adopted by Dr. Mayer, of Heilbronn, is as beautiful as it is
+ingenious: Conceive two equal portions of atmospheric air to be
+inclosed, at the same temperature--as at the freezing-point--in
+vessels each capable of containing one cubic foot; communicate heat to
+both, retaining the one portion at the original volume, and permitting
+the other to expand under a constant pressure equal to that of the
+atmosphere. In each vessel there will be inclosed 0.08073 pound, or
+1.29 ounce, of air. When, at the same temperature, the one has doubled
+its pressure and the other has doubled its volume, each will be at a
+temperature of 525.2° Fahr., or 274° C, and each will have double the
+original temperature, as measured on the absolute scale from the zero
+of heat-motion. But the one will have absorbed but 6-3/4 British
+thermal units, while the other will have absorbed 9-1/2. In the first
+case, all of this heat will have been employed in simply increasing
+the temperature of the air; in the second case, the temperature of the
+air will have been equally increased, and, besides, a certain amount
+of work--2,116.3 foot-pounds--must have been done in overcoming the
+resistance of the air; it is to this latter action that we must debit
+the additional heat which has disappeared. Now, 2,116.3/(2-3/4) = 770
+foot-pounds per heat-unit--almost precisely the value derived from
+Joule's experiments. Had Mayer's measurement been absolutely accurate,
+the result of his calculation would have been an exact determination
+of the heat-equivalent, provided no heat is, in this case, lost by
+internal work.
+
+Joule's most probably accurate measure was obtained by the use of a
+paddle-wheel revolving in water or other fluid. A copper vessel
+contained a carefully weighed portion of the fluid, and at the bottom
+was a step, on which stood a vertical spindle carrying the
+paddle-wheel. This wheel was turned by cords passing over
+nicely-balanced grooved wheels, the axles of which were carried on
+friction-rollers. Weights hung at the ends of these cords were the
+moving forces. Falling to the ground, they exerted an easily and
+accurately determinable amount of work, _W_ × _H_, which turned the
+paddle-wheel a definite number of revolutions, warming the water by
+the production of an amount of heat exactly equivalent to the amount
+of work done. After the weight had been raised and this operation
+repeated a sufficient number of times, the quantity of heat
+communicated to the water was carefully determined and compared with
+the amount of work expended in its development. Joule also used a pair
+of disks of iron rubbing against each other in a vessel of mercury,
+and measured the heat thus developed by friction, comparing it with
+the work done. The average of forty experiments with water gave the
+equivalent 772.692 foot-pounds; fifty with mercury gave 774.083;
+twenty with cast-iron gave 774.987--the temperature of the apparatus
+being from 55° to 60° Fahr.
+
+Joule also determined, by experiment, the fact that the expansion of
+air or other gas without doing work produces no change of temperature,
+which fact is predicable from the now known principles of
+thermo-dynamics. He stated the results of his researches relating to
+the mechanical equivalent of heat as follows:
+
+1. The heat produced by the friction of bodies, whether solid or
+liquid, is always proportional to the quantity of work expended.
+
+2. The quantity required to increase the temperature of a pound of
+water (weighed _in vacuo_ at 55° to 60° Fahr.) by one degree requires
+for its production the expenditure of a force measured by the fall of
+772 pounds from a height of one foot. This quantity is now generally
+called "Joule's equivalent."
+
+During this series of experiments, Joule also deduced the position of
+the "absolute zero," the point at which heat-motion ceases, and stated
+it to be about 480° Fahr. below the freezing-point of water, which is
+not very far from the probably true value,-493.2° Fahr. (-273° C.), as
+deduced afterward from more precise data.
+
+The result of these, and of the later experiments of Hirn and others,
+has been the admission of the following principle:
+
+Heat-energy and mechanical energy are mutually convertible and have a
+definite equivalence, the British thermal unit being equivalent to 772
+foot-pounds of work, and the metric _calorie_ to 423.55, or, as
+usually taken, 424 kilogrammetres. The exact measure is not fully
+determined, however.
+
+It has now become generally admitted that all forms of energy due to
+physical forces are mutually convertible with a definite
+quantivalence; and it is not yet determined that even vital and mental
+energy do not fall within the same great generalization. This
+quantivalence is the sole basis of the science of Energetics.
+
+The study of this science has been, up to the present time,
+principally confined to that portion which comprehends the relations
+of heat and mechanical energy. In the study of this department of the
+science, thermo-dynamics, Rankine, Clausius, Thompson, Hirn, and
+others have acquired great distinction. In the investigations which
+have been made by these authorities, the methods of transfer of heat
+and of modification of physical state in gases and vapors, when a
+change occurs in the form of the energy considered, have been the
+subjects of especial study.
+
+According to the law of Boyle and Marriotte, the expansion of such
+fluids follows a law expressed graphically by the hyperbola, and
+algebraically by the expression PV^{_x_} = A, in which, with
+unchanging temperature, _x_ is equal to 1. One of the first and most
+evident deductions from the principles of the equivalence of the
+several forms of energy is that the value of x must increase as the
+energy expended in expansion increases. This change is very marked
+with a vapor like steam--which, expanded without doing work, has an
+exponent less than unity, and which, when doing work by expanding
+behind a piston, partially condenses, the value of _x_ increases to,
+in the case of steam, 1.111 according to Rankine, or, probably more
+correctly, to 1.135 or more, according to Zeuner and Grashof. This
+fact has an important bearing upon the theory of the steam-engine, and
+we are indebted to Rankine for the first complete treatise on that
+theory as thus modified.
+
+Prof. Rankine began his investigations as early as 1849, at which time
+he proposed his theory of the molecular constitution of matter, now
+well known as the theory of molecular vortices. He supposes a system
+of whirling rings or vortices of heat-motion, and bases his
+philosophy upon that hypothesis, supposing sensible heat to be
+employed in changing the velocity of the particles, latent heat to be
+the work of altering the dimensions of the orbits, and considering the
+effort of each vortex to enlarge its boundaries to be due to
+centrifugal force. He distinguished between real and apparent specific
+heat, and showed that the two methods of absorption of heat, in the
+case of the heating of a fluid, that due to simple increase of
+temperature and that due to increase of volume, should be
+distinguished; he proposed, for the latter quantity, the term
+heat-potential, and for the sum of the two, the name of thermo-dynamic
+function.
+
+[Illustration: Prof. W. J. M. Rankine.]
+
+Carnot had stated, a quarter of a century earlier, that the efficiency
+of a heat-engine is a function of the two limits of temperature
+between which the machine is worked, and not of the nature of the
+working substance--an assertion which is quite true where the material
+does not change its physical state while working. Rankine now deduced
+that "general equation of thermo-dynamics" which expresses
+algebraically the relations between heat and mechanical energy, when
+energy is changing from the one state to the other, in which equation
+is given, for any assumed change of the fluids, the quantity of heat
+transformed. He showed that steam in the engine must be partially
+liquefied by the process of expanding against a resistance, and proved
+that the total heat of a perfect gas must increase with rise of
+temperature at a rate proportional to its specific heat under constant
+pressure.
+
+Rankine, in 1850, showed the inaccuracy of the then accepted value,
+0.2669, of the specific heat of air under constant pressure, and
+calculated its value as 0.24. Three years later, the experiments of
+Regnault gave the value 0.2379, and Rankine, recalculating it, made it
+0.2377. In 1851, Rankine continued his discussion of the subject, and,
+by his own theory, corroborated Thompson's law giving the efficiency
+of a perfect heat-engine as the quotient of the range of working
+temperature to the temperature of the upper limit, measured from the
+absolute zero.
+
+During this period, Clausius, the German physicist, was working on the
+same subject, taking quite a different method, studying the mechanical
+effects of heat in gases, and deducing, almost simultaneously with
+Rankine (1850), the general equation which lies at the beginning of
+the theory of the equivalence of heat and mechanical energy. He found
+that the probable zero of heat-motion is at such a point that the
+Carnot function must be approximately the reciprocal of the "absolute"
+temperature, as measured with the air thermometer, or, stated exactly,
+that quantity as determined by a perfect gas thermometer. He confirmed
+Rankine's conclusion relative to the liquefaction of saturated vapors
+when expanding against resistance, and, in 1854, adapted Carnot's
+principle to the new theory, and showed that his idea of the
+reversible engine and of the performance of a cycle in testing the
+changes produced still held good, notwithstanding Carnot's ignorance
+of the true nature of heat. Clausius also gave us the extremely
+important principle: It is impossible for a self-acting machine,
+unaided, to transfer heat from one body at a low temperature to
+another having a higher temperature.
+
+Simultaneously with Rankine and Clausius, Prof. William Thomson was
+engaged in researches in thermo-dynamics (1850). He was the first to
+express the principle of Carnot as adapted to the modern theory by
+Clausius in the now generally quoted propositions:[109]
+
+  [109] _Vide_ Tait's admirable "Sketch of Thermodynamics," second
+  edition, Edinburgh, 1877.
+
+1. When equal mechanical effects are produced by purely thermal
+action, equal quantities of heat are produced or disappear by
+transformation of energy.
+
+2. If, in any engine, a reversal effects complete inversion of all the
+physical and mechanical details of its operation, it is a perfect
+engine, and produces maximum effect with any given quantity of heat
+and with any fixed limits of range of temperature.
+
+William Thomson and James Thompson showed, among the earliest of their
+deductions from these principles, the fact, afterward confirmed by
+experiment, that the melting-point of ice should be lowered by
+pressure 0.0135° Fahr, for each atmosphere, and that a body which
+contracts while being heated will always have its temperature
+decreased by sudden compression. Thomson applied the principles of
+energetics in extended investigations in the department of
+electricity, while Helmholtz carried some of the same methods into his
+favorite study of acoustics.
+
+The application of now well-settled principles to the physics of gases
+led to many interesting and important deductions: Clausius explained
+the relations between the volume, density, temperature, and pressure
+of gases, and their modifications; Maxwell reëstablished the
+experimentally determined law of Dalton and Charles, known also as
+that of Gay-Lussac (1801), which asserts that all masses of equal
+pressure, volume, and temperature, contain equal numbers of molecules.
+On the Continent of Europe, also, Hirn, Zeuner, Grashof, Tresca,
+Laboulaye, and others have, during the same period and since,
+continued and greatly extended these theoretical researches.
+
+During all this time, a vast amount of experimental work has also been
+done, resulting in the determination of important data without which
+all the preceding labor would have been fruitless. Of those who have
+engaged in such work, Cagniard de la Tour, Andrews, Regnault, Hirn,
+Fairbairn and Tate, Laboulaye, Tresca, and a few others have directed
+their researches in this most important direction with the special
+object of aiding in the advancement of the new-born sciences. By the
+middle of the present century, the time which we are now studying,
+this set of data was tolerably complete. Boyle had, two hundred years
+before, discovered and published the law, which is now known by his
+name[110] and by that of Marriotte,[111] that the pressure of a gas
+varies inversely as its volume and directly as its density; Dr. Black
+and James Watt discovered, a hundred years later (1760), the latent
+heat of vapors, and Watt determined the method of expansion of steam;
+Dalton, in England, and Gay-Lussac, in France, showed, at the
+beginning of the nineteenth century, that all gaseous fluids are
+expanded by equal fractions of their volume by equal increments of
+temperature; Watt and Robison had given tables of the elastic force of
+steam, and Gren had shown that, at the temperature of boiling water,
+the pressure of steam was equal to that of the atmosphere; Dalton,
+Ure, and others proved (1800-1818) that the law connecting
+temperatures and pressures of steam was expressed by a geometrical
+ratio; and Biot had already given an approximate formula, when
+Southern introduced another, which is still in use.
+
+  [110] "New Experiments, Physico-Mechanical, etc., touching the
+  Spring of Air," 1662.
+
+  [111] "De la Nature de l'Air," 1676.
+
+The French Government established a commission in 1823 to experiment
+with a view to the institution of legislation regulating the working
+of steam-engines and boilers; and this commission, MM. de Prony,
+Arago, Girard, and Dulong, determined quite accurately the
+temperatures of steam under pressures running up to twenty-four
+atmospheres, giving a formula for the calculation of the one quantity,
+the other being known. Ten years later, the Government of the United
+States instituted similar experiments under the direction of the
+Franklin Institute.
+
+The marked distinction between gases, like oxygen and hydrogen, and
+condensible vapors, like steam and carbonic acid, had been, at this
+time, shown by Cagniard de la Tour, who, in 1822, studied their
+behavior at high temperatures and under very great pressures. He found
+that, when a vapor was confined in a glass tube in presence of the
+same substance in the liquid state, as where steam and water were
+confined together, if the temperature was increased to a certain
+definite point, the whole mass suddenly became of uniform character,
+and the previously existing line of demarkation vanished, the whole
+mass of fluid becoming, as he inferred, gaseous. It was at about this
+time that Faraday made known his then novel experiments, in which
+gases which had been before supposed permanent were liquefied, simply
+by subjecting them to enormous pressures. He then also first stated
+that, above certain temperatures, liquefaction of vapors was
+impossible, however great the pressure.
+
+Faraday's conclusion was justified by the researches of Dr. Andrews,
+who has since most successfully extended the investigation commenced
+by Cagniard de la Tour, and who has shown that, at a certain point,
+which he calls the "critical point," the properties of the two states
+of the fluid fade into each other, and that, at that point, the two
+become continuous. With carbonic acid, this occurs at 75 atmospheres,
+about 1,125 pounds per square inch, a pressure which would
+counterbalance a column of mercury 60 yards, or nearly as many metres,
+high. The temperature at this point is about 90° Fahr., or 31° Cent.
+For ether, the temperature is 370° Fahr., and the pressure 38
+atmospheres; for alcohol, they are 498° Fahr., and 120 atmospheres;
+and for bisulphide of carbon, 505° Fahr., and 67 atmospheres. For
+water, the pressure is too high to be determined; but the temperature
+is about 775° Fahr., or 413° Cent.
+
+Donny and Dufour have shown that these normal properties of vapors and
+liquids are subject to modification by certain conditions, as
+previously (1818) noted by Gay-Lussac, and have pointed out the
+bearing of this fact upon the safety of steam-boilers. It was
+discovered that the boiling-point of water could be elevated far above
+its ordinary temperature of ebullition by expedients which deprive the
+liquid of the air usually condensed within its mass, and which prevent
+contact with rough or metallic surfaces. By suspension in a mixture of
+oils which is of nearly the same density, Dufour raised drops of water
+under atmospheric pressure to a temperature of 356° Fahr.--180°
+Cent.--the temperature of steam of about 150 pounds per square inch.
+Prof. James Thompson has, on theoretical grounds, indicated that a
+somewhat similar action may enable vapor, under some conditions, to be
+cooled below the normal temperature of condensation, without
+liquefaction.
+
+Fairbairn and Tate repeated the attempt to determine the volume and
+temperature of water at pressures extending beyond those in use in the
+steam-engine, and incomplete determinations have also been made by
+others.
+
+Regnault is the standard authority on these data. His experiments
+(1847) were made at the expense of the French Government, and under
+the direction of the French Academy. They were wonderfully accurate,
+and extended through a very wide range of temperatures and pressures.
+The results remain standard after the lapse of a quarter of a century,
+and are regarded as models of precise physical work.[112]
+
+  [112] _See_ Porter on the Steam-Engine Indicator for the best set of
+  Regnault's tables generally accessible.
+
+Regnault found that the total heat of steam is not constant, but that
+the latent heat varies, and that the sum of the latent and sensible
+heats, or the total heat, increases 0.305 of a degree for each degree
+of increase in the sensible heat, making 0.305 the specific heat of
+saturated steam. He found the specific heat of superheated steam to be
+0.4805.
+
+Regnault promptly detected the fact that steam was not subject to
+Boyle's law, and showed that the difference is very marked. In
+expressing his results, he not only tabulated them but also laid them
+down graphically; he further determined exact constants for Biot's
+algebraic expression,
+
+  log. _p_ = _a_ - _b_A^{_x_} - _c_B^{_x_};
+
+making _x_ = 20 + _t_° Cent.; _a_ = 6.264035; log. _b_ = 0.1397743;
+log. _c_ = 0.6924351; log. A = [=1].9940493, and log. B = [=1].9983439;
+_p_ is the pressure in atmospheres. Regnault, in the expression for the
+total heat, H = A + _bt_, determined on the centigrade scale [theta] =
+606.5 + 0.305 _t_ Cent. For the Fahrenheit scale, we have the
+following equivalent expressions:
+
+  H = 1,113.44° + 0.305 _t_° Fahr., if measured from 0° Fahr.
+    = 1,091.9°  + 0.305 (_t_° - 32) Fahr.,;   } if measured from
+    = 1,081.94° + 0.305 _t_° Fahr.,           } the freezing-point.
+
+For latent heat, we have:
+
+  L = 606.5° - 0.695 _t_° Cent.
+    = 1,091.7°- 0.695 (_t_° - 32) Fahr.
+    = 1,113.94°- 0.695 _t_° Fahr.
+
+Since Regnault's time, nothing of importance has been done in this
+direction. There still remains much work to be done in the extension
+of the research to higher pressures, and under conditions which obtain
+in the operation of the steam-engine. The volumes and densities of
+steam require further study, and the behavior of steam in the engine
+is still but little known, otherwise than theoretically. Even the true
+value of Joule's equivalent is not undisputed.
+
+Some of the most recent experimental work bearing directly upon the
+philosophy of the steam-engine is that of Hirn, whose determination of
+the value of the mechanical equivalent was less than two per cent.
+below that of Joule. Hirn tested by experiment, in 1853, and
+repeatedly up to 1876, the analytical work of Rankine, which led to
+the conclusion that steam doing work by expansion must become
+gradually liquefied. Constructing a glass steam-engine cylinder, he
+was enabled to see plainly the clouds of mist which were produced by
+the expansion of steam behind the piston, where Regnault's experiments
+prove that the steam should become drier and superheated, were no heat
+transformed into mechanical energy. As will be seen hereafter, this
+great discovery of Rankine is more important in its bearing upon the
+theory of the steam-engine than any made during the century. Hirn's
+confirmation stands, in value, beside the original discovery. In 1858
+Hirn confirmed the work of Mayer and Joule by determining the work
+done and the carbonic acid produced, as well as the increased
+temperature due to their presence, where men were set at work in a
+treadmill; he found the elevation of temperature to be much greater in
+proportion to gas produced when the men were resting than when they
+were at work. He thus proved conclusively the conversion of
+heat-energy into mechanical work. It was from these experiments that
+Helmholtz deduced the "modulus of efficiency" of the human machine at
+one-fifth, and concluded that the heart works with eight times the
+efficiency of a locomotive-engine, thus confirming a statement of
+Rumford, who asserted the higher efficiency of the animal.
+
+Hirn's most important experiments in this department were made upon
+steam-engines of considerable size, including simple and compound
+engines, and using steam sometimes saturated and sometimes superheated
+to temperatures as high, on some occasions, as 340° Cent. He
+determined the work done, the quantity of heat entering, and the
+amount rejected from, the steam-cylinder, and thus obtained a coarse
+approximation to the value of the heat-equivalent. His figure varied
+from 296 to 337 kilogrammetres. But, in all cases, the loss of heat
+due to work done was marked, and, while these researches could not, in
+the nature of the case, give accurate quantitative results, they are
+of great value as qualitatively confirming Mayer and Joule, and
+proving the transformation of energy.
+
+Thus, as we have seen, experimental investigation and analytical
+research have together created a new science, and the philosophy of
+the steam-engine has at last been given a complete and well-defined
+form, enabling the intelligent engineer to comprehend the operation of
+the machine, to perceive the conditions of efficiency, and to look
+forward in a well-settled direction for further advances in its
+improvement and in the increase of its efficiency.
+
+A very concise _résumé_ of the principal facts and laws bearing upon
+the philosophy of the steam-engine will form a fitting conclusion to
+this historical sketch.
+
+The term "energy" was first used by Dr. Young as the equivalent of the
+work of a moving body, in his hardly yet obsolete "Lectures on Natural
+Philosophy."
+
+Energy is the capacity of a moving body to overcome resistance offered
+to its motion; it is measured either by the product of the mean
+resistance into the space through which it is overcome, or by the
+half-product of the mass of the body into the square of its velocity.
+Kinetic energy is the actual energy of a moving body; potential energy
+is the measure of the work which a body is capable of doing under
+certain conditions which, without expending energy, may be made to
+affect it, as by the breaking of a cord by which a weight is
+suspended, or by firing a mass of explosive material. The British
+measure of energy is the foot-pound; the metric measure is the
+kilogrammetre.
+
+Energy, whether kinetic or potential, may be observable and due to
+mass-motion; or it may be invisible and due to molecular movements.
+The energy of a heavenly body or of a cannon-shot, and that of heat or
+of electrical action, are illustrations of the two classes. In Nature
+we find utilizable potential energy in fuel, in food, in any available
+head of water, and in available chemical affinities. We find kinetic
+energy in the motion of the winds and the flow of running water, in
+the heat-motion of the sun's rays, in heat-currents on the earth, and
+in many intermittent movements of bodies acted on by applied forces,
+natural or artificial. The potential energy of fuel and of food has
+already been seen to have been derived, at an earlier period, from the
+kinetic energy of the sun's rays, the fuel or the food being thus made
+a storehouse or reservoir of energy. It is also seen that the animal
+system is simply a "mechanism of transmission" for energy, and does
+not create but simply diverts it to any desired direction of
+application.
+
+All the available forms of energy can be readily traced back to a
+common origin in the potential energy of a universe of nebulous
+substance (chaos), consisting of infinitely diffused matter of
+immeasurably slight density, whose "energy of position" had been,
+since the creation, gradually going through a process of
+transformation into the several forms of kinetic and potential energy
+above specified, through intermediate methods of action which are
+usually still in operation, such as the potential energy of chemical
+affinity, and the kinetic forms of energy seen in solar radiation, the
+rotation of the earth, and the heat of its interior.
+
+The _measure_ of any given quantity of energy, whatever may be its
+form, is the product of the resistance which it is capable of
+overcoming into the space through which it can move against that
+resistance, i. e., by the product RS. Or it is measured by the
+equivalent expressions (MV^{2})/2, or WV^{2}/2_g_, in which W is
+the weight, M is the "mass" of matter in motion, V the velocity, and
+_g_ the dynamic measure of the force of gravity, 32-1/6 feet, or 9.8
+metres, per second.
+
+There are three great laws of energetics:
+
+1. The sum total of the energy of the universe is invariable.
+
+2. The several forms of energy are interconvertible, and possess an
+exact quantitative equivalence.
+
+3. The tendency of all forms of kinetic energy is continually toward
+reduction to forms of molecular motion, and to their final dissipation
+uniformly throughout space.
+
+The history of the first two of these laws has already been traced.
+The latter was first enunciated by Prof. Sir William Thomson in 1853.
+Undissipated energy is called "Entrophy."
+
+The science of thermo-dynamics is, as has been stated, a branch of the
+science of energetics, and is the only branch of that science in the
+domain of the physicist which has been very much studied. This branch
+of science, which is restricted to the consideration of the relations
+of heat-energy to mechanical energy, is based upon the great fact
+determined by Rumford and Joule, and considers the behavior of those
+fluids which are used in heat-engines as the media through which
+energy is transferred from the one form to the other. As now accepted,
+it assumes the correctness of the hypothesis of the dynamic theory of
+fluids, which supposes their expansive force to be due to the motion
+of their molecules.
+
+This idea is as old as Lucretius, and was distinctly expressed by
+Bernouilli, Le Sage and Prévost, and Herapath. Joule recalled
+attention to this idea, in 1848, as explaining the pressure of gases
+by the impact of their molecules upon the sides of the containing
+vessels. Helmholtz, ten years later, beautifully developed the
+mathematics of media composed of moving, frictionless particles, and
+Clausius has carried on the work still further.
+
+The general conception of a gas, as held to-day, including the
+vortex-atom theory of Thomson and Rankine, supposes all bodies to
+consist of small particles called molecules, each of which is a
+chemical aggregation of its ultimate parts or atoms. These molecules
+are in a state of continual agitation, which is known as heat-motion.
+The higher the temperature, the more violent this agitation; the total
+quantity of motion is measured as _vis viva_ by the half-product of
+the mass into the square of the velocity of molecular movement, or in
+heat-units by the same product divided by Joule's equivalent. In
+solids, the range of motion is circumscribed, and change of form
+cannot take place. In fluids, the motion of the molecules has become
+sufficiently violent to enable them to break out of this range, and
+their motion is then no longer definitely restricted.
+
+The laws of thermo-dynamics are, according to Rankine:
+
+1. Heat-energy and mechanical energy are mutually convertible, one
+British thermal unit being the equivalent in heat-energy of 772
+foot-pounds of mechanical energy, and one metric _calorie_ equal to
+423.55 kilogrammetres of work.
+
+2. The energy due to the heat of each of the several equal parts into
+which a uniformly hot substance may be divided is the same; and the
+total heat-energy of the mass is equal to the sum of the energies of
+its parts.[113]
+
+  [113] This uniformity is not seen where a substance is changing its
+  physical state while developing its heat-energy, as occurs with
+  steam doing work while expanding.
+
+It follows that the work performed by the transformation of the energy
+of heat, during any indefinitely small variation of the state of a
+substance as respects temperature, is measured by the product of the
+absolute temperature into the variation of a "function," which
+function is the rate of variation of the work so done with
+temperature. This function is the quantity called by Rankine the
+"heat-potential" of the substance for the given kind of work. A
+similar function, which comprehends the total heat-variation,
+including both heat transformed and heat needed to effect accompanying
+physical changes, is called the "thermo-dynamic function." Rankine's
+expression for the general equation of thermo-dynamics includes the
+latter, and is given by him as follows:
+
+  J_dh_ = _d_H = _kd_[tau] + [tau]_d_F = [tau]_d_[phi],
+
+in which J is Joule's equivalent, _dh_ the variation of total heat in
+the substance, _kd_[tau] the product of the "dynamic specific heat"
+into the variation of temperature, or the total heat demanded to
+produce other changes than a transformation of energy, and [tau]_d_F
+is the work done by the transformation of heat-energy, or the product
+of the absolute temperature, [tau], into the differential of the
+heat-potential. [phi] is the thermo-dynamic function, and
+[tau]_d_[phi] measures the whole heat needed to produce,
+simultaneously, a certain amount of work or of mechanical energy, and,
+at the same time, to change the temperature of the working substance.
+
+Studying the behavior of gases and vapors, it is found that the work
+done when they are used, like steam, in heat-engines, consists of
+three parts:
+
+(_a._) The change effected in the total actual heat-motion of the
+fluid.
+
+(_b._) That heat which is expended in the production of internal work.
+
+(_c._) That heat which is expended in doing the external work of
+expansion.
+
+In any case in which the total heat expended exceeds that due the
+production of work on external bodies, the excess so supplied is so
+much added to the intrinsic energy of the substance absorbing it.
+
+The application of these laws to the working of steam in the engine is
+a comparatively recent step in the philosophy of the steam-engine, and
+we are indebted to Rankine for the first, and as yet only, extended
+and in any respect complete treatise embodying these now accepted
+principles.
+
+It was fifteen years after the publication of the first logical theory
+of the steam-engine, by Pambour,[114] before Rankine, in 1859, issued
+the most valuable of all his works, "The Steam-Engine and other Prime
+Movers." The work is far too abstruse for the general reader, and is
+even difficult reading for many accomplished engineers. It is
+excellent beyond praise, however, as a treatise on the thermo-dynamics
+of heat-engines. It will be for his successors the work of years to
+extend the application of the laws which he has worked out, and to
+place the results of his labors before students in a readily
+comprehended form.
+
+  [114] "Théorie de la Machine à Vapeur," par le Chevalier F. M. G. de
+  Pambour, Paris, 1844.
+
+William J. Macquorn Rankine, the Scotch engineer and philosopher, will
+always be remembered as the author of the modern philosophy of the
+steam-engine, and as the greatest among the founders of the science of
+thermo-dynamics. His death, while still occupying the chair of
+engineering at the University of Glasgow, December 24, 1872, at the
+early age of fifty-two, was one of the greatest losses to science and
+to the profession which have occurred during the century.
+
+
+
+
+CHAPTER VIII.
+
+_THE PHILOSOPHY OF THE STEAM-ENGINE._
+
+ITS APPLICATION; ITS TEACHINGS RESPECTING THE CONSTRUCTION OF THE
+ENGINE AND ITS IMPROVEMENT.
+
+  "Oftentimes an Uncertaintie hindered our going on so merrily, but by
+  persevering the Difficultie was mastered, and the new Triumph gave
+  stronger Heart unto us."--RALEIGH.
+
+  "If everything which we cannot comprehend is to be called an
+  impossibility, how many are daily presented to our eyes! and in
+  contemning as false that which we consider to be impossible, may we
+  not be depreciating a giant's effort to give an importance to our
+  own weakness?"--MONTAIGNE.
+
+  "They who aim vigorously at perfection will come nearer to it than
+  those whose laziness or despondency makes them give up its pursuit
+  from the feeling of its being unattainable."--CHESTERFIELD.
+
+
+As has been already stated, the steam-engine is a machine which is
+especially designed to transform energy, originally dormant or
+potential, into active and usefully available kinetic energy.
+
+When, millions of years ago, in that early period which the geologists
+call the carboniferous, the kinetic energy of the sun's rays, and of
+the glowing interior of the earth, was expended in the decomposition
+of the vast volumes of carbonic acid with which air was then charged,
+and in the production of a life-sustaining atmosphere and of the
+immense forests which then covered the earth with their almost
+inconceivably luxuriant vegetation, there was stored up for the
+benefit of the human race, then uncreated, an inconceivably great
+treasure of potential energy, which we are now just beginning to
+utilize. This potential energy becomes kinetic and available wherever
+and whenever the powerful chemical affinity of oxygen for carbon is
+permitted to come into play; and the fossil fuel stored in our
+coal-beds or the wood of existing forests is, by the familiar process
+of combustion, permitted to return to the state of combination with
+oxygen in which it existed in the earliest geological periods.
+
+The philosophy of the steam-engine, therefore, traces the changes
+which occur from this first step, by which, in the furnace of the
+steam-boiler, this potential energy which exists in the tendency of
+carbon and oxygen to combine to form carbonic acid is taken advantage
+of, and the utilizable kinetic energy of heat is produced in
+equivalent amount, to the final application of resulting mechanical
+energy to machinery of transmission, through which it is usefully
+applied to the elevation of water, to the driving of mills and
+machinery of all kinds, or to the hauling of "lightning" trains on our
+railways, or to the propulsion of the Great Eastern.
+
+The kinetic heat-energy developed in the furnace of the steam-boiler
+is partly transmitted through the metallic walls which inclose the
+steam and water within the boiler, there to evaporate water, and to
+assume that form of energy which exists in steam confined under
+pressure, and is partly carried away into the atmosphere in the
+discharged gaseous products of combustion, serving, however, a useful
+purpose, _en route_, by producing the draught needed to keep up
+combustion.
+
+The steam, with its store of heat-energy, passes through tortuous
+pipes and passages to the steam-cylinder of the engine, losing more or
+less heat on the way, and there expands, driving the piston before it,
+and losing heat by the transformation of that form of energy while
+doing mechanical work of equivalent amount. But this steam-cylinder is
+made of metal, a material which is one of the best conductors of heat,
+and therefore one of the very worst possible substances with which to
+inclose anything as subtile and difficult of control as the heat
+pervading a condensible vapor like steam. The process of internal
+condensation and reëvaporation, which is the great enemy of economical
+working, thus has full play, and is only partly checked by the heat
+from the steam-jacket, which, penetrating the cylinder, assists by
+keeping up the temperature of the internal surface and checking the
+first step, condensation, which is an essential preliminary to the
+final waste by reëvaporation. The piston, too, is of metal, and
+affords a most excellent way of exit for the heat escaping to the
+exhaust side.
+
+Finally, all unutilized heat rejected from the steam-cylinder is
+carried away from the machine, either by the water of condensation,
+or, in the non-condensing engine, by the atmosphere into which it is
+discharged.
+
+Having traced the method of operation of the steam-engine, it is easy
+to discover what principles are comprehended in its philosophy, to
+learn what are known facts bearing upon its operation, and to
+determine what are the directions in which improvement must take
+place, what are the limits beyond which improvement cannot possibly be
+carried, and, in some directions, to determine what is the proper
+course to pursue in effecting improvements. The general direction of
+change in the past, as well as at present, is easily seen, and it may
+usually be assumed that there will be no immediate change of direction
+in a course which has long been preserved, and which is well defined.
+We may, therefore, form an idea of the probable direction in which to
+look for improvement in the near future.
+
+Reviewing the operations which go on in this machine during the
+process of transformation of energy which has been outlined, and
+studying it more in detail, we may deduce the principles which govern
+its design and construction, guide us in its management, and determine
+its efficiency.
+
+In the furnace of the boiler, the quantity of heat developed in
+available form is proportional to the amount of fuel burned. It is
+available in proportion to the temperature attained by the products of
+combustion; were this temperature no higher than that of the boiler,
+the heat would all pass off unutilized. But the temperature produced
+by a given quantity of heat, measured in heat-units, is greater as the
+volume of gas heated is less. It follows that, at this point,
+therefore, the fuel should be perfectly consumed with the least
+possible air-supply, and the least possible abstraction of heat before
+combustion is complete. High temperature of furnace, also, favors
+complete combustion. We hence conclude that, in the steam-boiler
+furnace, fuel should be burned completely in a chamber having
+non-conducting walls, and with the smallest air-supply compatible with
+thorough combustion; and, further, that the air should be free from
+moisture, that greatest of all absorbents of heat, and that the
+products of combustion should be removed from the furnace before
+beginning to drain their heat into the boiler. A fire-brick furnace, a
+large combustion-chamber with thorough intermixture of gases within
+it, good fuel, and a restricted and carefully-distributed supply of
+air, seem to be the conditions which meet these requisites best.
+
+The heat generated by combustion traverses the walls which separate
+the gases of the furnace from the steam and water confined within the
+boiler, and is then taken up by those fluids, raising their
+temperature from that of the entering "feed-water" to that due the
+steam-pressure, and expanding the liquid into steam occupying a
+greatly-increased volume, thus doing a certain amount of work, besides
+increasing temperature. The extent to which heat may thus be usefully
+withdrawn from the furnace-gases depends upon the conductivity of the
+metallic wall, the rate at which the water will take heat from the
+metal, and the difference of temperature on the two sides of the
+metal. Extended "heating-surface," therefore, a metal of high
+conducting power, and a maximum difference of temperature on the two
+sides of the separating wall of metal, are the essential conditions of
+economy here. The heating-surface is sometimes made of so great an
+area that the temperature of the escaping gases is too low to give
+good chimney-draught, and a "mechanical draught" is resorted to,
+revolving "fan-blowers" being ordinarily used for its production. It
+is most economical to adopt this method. The steam-boiler is generally
+constructed of iron--sometimes, but rarely, of cast-iron, although
+"steel," where not hard enough to harden or temper, is better in
+consequence of its greater strength and homogeneousness of structure,
+and its better conductivity. The maximum conductivity of flow of heat
+for any given material is secured by so designing the boiler as to
+secure rapid, steady, and complete circulation of the water within it.
+The maximum rapidity of transfer throughout the whole area of
+heating-surface is secured, usually, by taking the feed-water into the
+boiler as nearly as possible at the point where the gases are
+discharged into the chimney-flue, withdrawing the steam nearer the
+point of maximum temperature of flues, and securing opposite
+directions of flow for the gases on the one side and the water on the
+other. Losses of heat from the boiler, by conduction and radiation to
+surrounding bodies, are checked as far as possible by non-conducting
+coverings.
+
+The mechanical equivalent of the heat generated in the boiler is
+easily calculated when the conditions of working are known. A pound of
+pure carbon has been found to be capable of liberating by its perfect
+combustion, resulting in the formation of carbonic acid, 14,500
+British thermal units, equivalent to 14,500 × 772 = 11,194,000
+foot-pounds of work, and, if burned in one hour, to 11194000/1980000 =
+5.6 horse-power. In other words, with perfect utilization, but 10/56 =
+0.177, or about one-sixth, of a pound of carbon would be needed per
+hour for each horse-power of work done. But even good coal is not
+nearly all carbon, and has but about nine-tenths this heat-producing
+power, and it is usually rated as yielding about 10,000,000
+foot-pounds of work per pound. The evaporative power of pure carbon
+being rated at 15 pounds of water, that of good coal may be stated at
+13-1/2. In metric measures, one gramme of good coal should evaporate
+about 13-1/2 grammes of water from the boiling-point, producing the
+equivalent of about 3,000,000 kilogrammetres of work from the 7,272
+_calories_ of heat thus generated. A gramme of pure carbon generates
+in its combustion 8,080 _calories_ of heat. Per hour and per
+horse-power, 0.08, or less than one-twelfth, of a kilogram of carbon
+burned per hour evolves heat-energy equal to one horse-power.
+
+Of the coal burned in a steam-boiler, it rarely happens that more than
+three-fourths is utilized in making steam; 7,500,000 foot-pounds
+(1,036,898 kilogrammetres) is, therefore, as much energy as is usually
+sent to the engine per pound of good coal burned in the steam-boiler.
+The "efficiency" of a good steam-boiler is therefore usually not far
+from 0.75 as a maximum. Rankine estimates this quantity for ordinary
+boilers of good design and with chimney-draught at
+
+          0.92
+  E = ------------;
+      1 + 0.5(F/S)
+
+in which F/S is the ratio of weight of fuel burned per square foot of
+grate to the ratio of heating to grate surface; this is a formula of
+fairly close approximation for general practice.
+
+The steam in the engine first drives the piston some distance before
+the induction or steam valve is closed, and it then expands, doing
+work, and condensing in proportion to work done as the expansion
+proceeds, until it is finally released by the opening of the exhaust
+or eduction valve. Saturated steam is modified in its action by a
+process which has already been described, condensing at the beginning
+and reëvaporating at the end of the stroke, thus carrying into the
+condenser considerable quantities of heat which should have been
+utilized in the development of power. Whether this operation takes
+place in one cylinder or in several is only of importance in so far as
+it modifies the losses due to conduction and radiation of heat, to
+condensation and reëvaporation of steam, and to the friction of the
+machine. It has already been seen how these losses are modified by the
+substitution of the compound for the single-cylinder engine.
+
+The laws of thermo-dynamics teach, as has been stated, that the
+proportion of the heat-energy contained in the steam or other working
+fluid which may be transformed into mechanical energy is a fraction
+(H_{1} - H_{2})/H_{1}, of the total, in which H_{1} and H_{2} are the
+quantities of heat contained in the steam at the beginning and at the
+end of its operation, measuring from the absolute zero of heat-motion.
+In perfect gases,
+
+  H_{1} - H_{2}   [tau]_{1} - [tau]_{2}      T_{1} - T_{2}
+  ------------- = --------------------- = --------------------
+      H_{1}             [tau]_{1}         T_{1} + 461.2° Fahr.
+
+but in imperfect gases, and especially in vapors which, like steam,
+condense, or otherwise change their physical state, this equality may
+still exist,
+
+  (H_{1} - H_{2})/H_{1} = ([tau]_{1} - [tau]_{2})/[tau]_{1};
+
+and the fluid is equally efficient with the
+perfect gas as a working substance in a heat-engine. In any case it is
+seen that the efficiency is greatest when the whole of the heat is
+received at the maximum and rejected at the minimum attainable
+temperatures.
+
+Assuming this expression strictly accurate, a hot-air engine working
+from 413.6° Fahr, or 874.8° absolute temperature, down to 122° Fahr,
+or 583.2° absolute, should have an efficiency of 0.263, transforming
+that proportion of available heat into mechanical work. The engines
+of the steamer Ericsson closely approached this figure, and gave a
+horse-power for each 1.87 pound of coal burned per hour.
+
+Steam expands in the steam-cylinder quite differently under different
+circumstances. If no heat is either communicated to it or abstracted
+from it, however, it expands in an hyperbolic curve, losing its
+tension much more rapidly than when expanded without doing work, in
+consequence both of its change of volume and its condensation. The
+algebraic expression for this method of expansion is, according to
+Rankine, PV^{1.111} = C, a constant, or, according to other
+authorities, from PV^{1.135} = C to PV^{1.140} = C. The greater the
+value of the exponent of V, the greater the efficiency of the fluid
+between any two temperatures. The maximum value has been found to be
+given where the steam is saturated, but perfectly dry, at the
+commencement of its expansion. The loss due to condensation on the
+cooled interior surface of the cylinder at the commencement of the
+stroke and the subsequent reëvaporation as expansion progresses is
+least when the cylinder is kept hot by its steam-jacket and when least
+time is given during the stroke for this transfer of heat between the
+metal and the vapor.
+
+It may be said that, all things considered, therefore, losses of heat
+in the steam-cylinder are least when the steam enters dry, or
+moderately superheated, where the interior surfaces are kept hottest
+by the steam-jacket or by the hot-air jacket sometimes used, and where
+piston-speed and velocity of rotation are highest.[115] The best of
+compound engines, using steam of seventy-five pounds pressure and
+condensing, usually require about two pounds of coal per
+hour--20,000,000 foot-pounds of energy at the furnace--to develop a
+horse-power, i. e., about ten times the heat-equivalent of the
+mechanical work which they accomplish. Were the steam to expand like
+the permanent gases, they would have a theoretical efficiency of about
+one-quarter; actually, the efficiency is only one-tenth. The
+steam-engine, therefore, utilizes about two-fifths the heat-energy
+theoretically available with the best type of engine in general use.
+By far the greater part, nearly all, in fact, of the nine-tenths
+wasted is rejected in the exhaust steam, and can only be saved by some
+such method as is hereafter to be suggested of retaining that heat and
+returning it to the boiler.
+
+  [115] In some cases, as in the Allen engine, the speed of piston has
+  become very high, approaching 800((stroke)^{1/3}).
+
+The mechanical power which has now been communicated to the mechanism
+of the engine by the transfer of the kinetic energy of the hot steam
+to the piston is finally usefully applied to whatever "mechanism of
+transmission" forms the connection with the machinery driven by the
+engine. In this transfer, there is some loss in the engine itself, by
+friction. This is an extremely variable amount, and it can be made
+very small by skillful design and good workmanship and management. It
+may be taken at one-half pound per square inch of piston for good
+engines of 100 horse-power and upward, but is often several pounds in
+very small engines. It is least when the rubbing surfaces are of
+different materials, but both of smooth, hard, close-grained metal,
+well lubricated, and where advantage is taken of any arrangement of
+parts which permits the equilibration of pressure, as on the
+shaft-bearings of double and triple engines. The friction of a
+steam-engine of large size and good design is usually between five and
+seven per cent. of its total power. It increases rapidly as the size
+of engine decreases.
+
+Having now traced somewhat minutely the growth of the steam-engine
+from the beginning of the Christian era to the present time, having
+rapidly outlined the equally gradual, though intermittent, growth of
+its philosophy, and having shown how the principles of science find
+application in the operation of this wonderful machine, we are now
+prepared to study the conditions which control the intelligent
+designer, and to endeavor to learn what are the lessons taught us by
+science and by experience in regard to the essential requisites of
+efficient working of steam and economy in the consumption of fuel. We
+may even venture to point out definitely the direction in which
+improvement is now progressing as indicated by a study of these
+requisites, and may be able to perceive the natural limits to such
+progress, and possibly to conjecture what must be the character of
+that change of type which only can take the engineer beyond the limit
+set to his advance so long as he is confined to the construction of
+the present type of engine.
+
+First, we must consider the question: _What is the problem, stated
+precisely and in its most general form, that engineers have been here
+attempting to solve?_
+
+After stating the problem, we will examine the record with a view to
+determine what direction the path of improvement has taken hitherto,
+to learn what are the conditions of efficiency which should govern the
+construction of the modern steam-engine, and, so far as we may judge
+the future by the past, by inference, to ascertain what appears to be
+the proper course for the present and for the immediate future. Still
+further, we will inquire, what are the conditions, physical and
+intellectual, which best aid our progress in perfecting the
+steam-engine.
+
+This most important problem may be stated in its most general, yet
+definite, form as follows:
+
+_To construct a machine which shall, in the most perfect manner
+possible, convert the kinetic energy of heat into mechanical power,
+the heat being derived from the combustion of fuel, and steam being
+the receiver and the conveyer of that heat._
+
+The problem, as we have already seen, embodies two distinct and
+equally important inquiries:
+
+The first: What are the scientific principles involved in the problem
+as stated?
+
+The second: How shall a machine be constructed that shall most
+efficiently embody, and accord with, not only those scientific
+principles, but also all of those principles of engineering practice
+that so vitally affect the economical value of every machine?
+
+The one question is addressed to the man of science, the other to the
+engineer. They can be satisfactorily answered, even so far as our
+knowledge at present permits, after studying with care the scientific
+principles involved in the theory of the steam-engine under the best
+light that science can afford us, and by a careful study of the
+various steps of improvement that have taken place and of accompanying
+variations of structure, analyzing the effect of each change, and
+tracing the reasons for them.
+
+The theory of the steam-engine is too important and too extensive a
+subject to be satisfactorily treated here in even the most concise
+possible manner. I can only attempt a plain statement of the course
+which seems to be pointed out by science as the proper one to pursue
+in the endeavor to increase the economical efficiency of
+steam-engines.
+
+The teachings of science indicate that _success in economically
+deriving mechanical power from the energy of heat-motion will, in all
+cases, be the greater as we work between more widely separated limits
+of temperature, and as we more perfectly provide against losses by
+dissipation of heat in directions in which it is unavailable for the
+production of power_.
+
+Scientific research, as we have seen, has proved that, in all known
+varieties of heat-engine, a large loss of effect is unavoidable from
+the fact that we cannot, in the ordinary steam-engine, reduce the
+lower limit of temperature, in working, below a point which is far
+above the absolute zero of temperature--far above that point at which
+bodies have no heat-motion. The point corresponding to the mean
+temperature of the surface of the earth is above the ordinary lower
+limit.
+
+The higher the temperature of the steam when it enters the steam
+cylinder, and the lower that which it reaches before the exhaust
+occurs, the greater, science tells us, will be our success, provided
+we at the same time avoid waste of heat and power.
+
+Now, looking back over the history of the steam-engine, we may briefly
+note the prominent improvements and the most striking changes of form,
+and may thus endeavor to obtain some idea of the general direction in
+which we are to look for further advance.
+
+Beginning with the machine of Porta, at which point we may first take
+up an unbroken thread, it will be remembered that we there found a
+single vessel performing the functions of all the parts of a modern
+pumping-engine; it was, at once, boiler, steam-cylinder, and
+condenser, as well as both a lifting and a forcing pump.
+
+The Marquis of Worcester divided the engine into two parts, using a
+separate boiler.
+
+Savery duplicated that part of the engine of Worcester which performed
+the several parts of pump, steam-cylinder, and condenser, and added
+the use of water to effect rapid condensation, perfecting, so far as
+it was ever perfected, the steam-engine as a simple machine.
+
+Newcomen and Calley next separated the pump from the steam-engine
+proper, producing the modern steam-engine--the engine as a train of
+mechanism; and in their engine, as in Savery's, we noticed the use of
+surface condensation first, and subsequently that of the jet thrown
+into the midst of the steam to be condensed.
+
+Watt finally effected the crowning improvements, and completed the
+movement o£ "differentiation" by separating the condenser from the
+steam-cylinder. Here this process of change ceased, the several
+important operations of the steam-engine now being conducted each in a
+separate vessel. The boiler furnished the steam, the cylinder derived
+from it mechanical power, and it was finally condensed in a separate
+vessel, while the power which had been obtained from it in the
+steam-cylinder was transmitted through still other parts, to the
+pumps, or wherever work was to be done.
+
+Watt, also, took the initiative in another direction. He continually
+increased the efficiency of the machine by improving the proportions
+of its parts and the character of its workmanship, thus making it
+possible to render available many of those improvements in detail upon
+which effectiveness is so greatly dependent and which are only useful
+when made by a skillful workman.
+
+Watt and his contemporaries also commenced that movement toward higher
+pressures of steam and greater expansion which has been the most
+striking feature noticed in the progress of steam-engineering since
+his time. Newcomen used steam of barely more than atmospheric pressure
+and raised 105,000 pounds of water one foot high with a pound of coal
+consumed. Smeaton raised the pressure somewhat and increased the duty
+considerably. Watt started with a duty double that of Newcomen and
+raised it to 320,000 foot-pounds per pound of coal, with steam at 10
+pounds pressure. To-day, Cornish engines of the same general plan as
+those of Watt, but worked with 40 to 60 pounds of steam and expanding
+three or four times, do a duty probably averaging, with the better
+class of engines, 600,000 foot-pounds per pound of coal. The compound
+pumping-engine runs the figure up to above 1,000,000.
+
+The increase in steam-pressure and in expansion since Watt's time has
+been accompanied by a very great improvement in workmanship--a
+consequence, very largely, of the rapid increase in perfection, and in
+the wide range of adaptation of machine-tools--by higher skill and
+intelligence in designing engines and boilers, by increased
+piston-speed, greater care in obtaining dry steam, and in keeping it
+dry until thrown out of the cylinder, either by steam-jacketing or by
+superheating, or both combined; it has further been accompanied by a
+greater attention to the important matter of providing carefully
+against losses by radiation and conduction of heat. We use, finally,
+the compound or double-cylinder engine for the purpose of saving some
+of the heat usually lost in internal condensation and reëvaporation,
+and precipitation of condensed vapor from great expansion.
+
+It is evident that, although there is a limit, tolerably well defined,
+in the scale of temperature, below which we cannot expect to pass, a
+degree gained in approaching this lower limit is more remunerative
+than a degree gained in the range of temperature available by
+increasing temperatures.[116]
+
+  [116] The fact here referred to is easily seen if it is supposed
+  that an engine is supplied with steam at a temperature of 400°
+  above absolute zero and works it, without waste, down to a
+  temperature of 200°. Suppose one inventor to adapt the engine to the
+  use of steam of a range from 500° down to 200°, while another works
+  his engine, with equally effective provision against losses, between
+  the limits of 400° and 100°, an equal range with a lower mean. The
+  first case gives an efficiency of one-half, the second three-fifths,
+  and the third three-fourths, the last giving the highest effect.
+
+Hence the attempt made by the French inventor, Du Trembly, about the
+year 1850, and by other inventors since, to utilize a larger
+proportion of heat by approaching more closely the lower limit, was in
+accordance with known scientific principles.
+
+We may summarize the result of our examination of the growth of the
+steam-engine thus:
+
+_First._ The process of improvement has been one, primarily, of
+"differentiation;"[117] the number of parts has been continually
+increased; while the work of each part has been simplified, a separate
+organ being appropriated to each process in the cycle of operations.
+
+  [117] This term, though perhaps not familiar to engineers, expresses
+  the idea perfectly.
+
+_Secondly._ A kind of secondary process of differentiation has, to
+some extent, followed the completion of the primary one, in which
+secondary process one operation is conducted partly in one and partly
+in another portion of the machine. This is illustrated by the two
+cylinders of the compound engine and by the duplication noticed in the
+binary engine.
+
+_Thirdly._ The direction of improvement has been marked by a continual
+increase of steam-pressure, greater expansion, provision for obtaining
+dry steam, high piston-speed, careful protection against loss of heat
+by conduction or radiation, and, in marine engines, by surface
+condensation.
+
+The direction which improvement seems now to be taking, and the proper
+direction, as indicated by an examination of the principles of
+science, as well as by our review of the steps already taken, would
+seem to be: working between the widest attainable limits of
+temperature.
+
+Steam must enter the machine at the highest possible temperature, must
+be protected from waste, and must retain, at the moment before
+exhaust, the least possible amount of heat. He whose inventive genius,
+or mechanical skill, contributes to effect either the use of higher
+steam with safety and without waste, or the reduction of the
+temperature of discharge, confers a boon upon mankind.
+
+In detail: In the engine, the tendency is, and may probably be
+expected to continue, in the near future at least, toward higher
+steam-pressure, greater expansion in more than one cylinder,
+steam-jacketing, superheating, a careful use of non-conducting
+protectors against waste, and the adoption of still higher
+piston-speeds.
+
+In the boiler: more complete combustion without excess of air passing
+through the furnace, and more thorough absorption of heat from the
+furnace-gases. The latter will probably be ultimately effected by the
+use of a mechanically produced draught, in place of the far more
+wasteful method of obtaining it by the expenditure of heat in the
+chimney.
+
+In construction we may anticipate the use of better materials, and
+more careful workmanship, especially in the boiler, and much
+improvement in forms and proportions of details.
+
+In management, there is a wide field for improvement, which
+improvement we may feel assured will rapidly take place, as it has now
+become well understood that great care, skill, and intelligence are
+important essentials to the economical management of the steam-engine,
+and that they repay, liberally, all of the expense in time and money
+that is requisite to secure them.
+
+In attempting improvements in the directions indicated, it would be
+the height of folly to assume that we have reached a limit in any one
+of them, or even that we have approached a limit. If further progress
+seems checked by inadequate returns for efforts made, in any case, to
+advance beyond present practice, it becomes the duty of the engineer
+to detect the cause of such hinderance, and, having found it, to
+remove it.
+
+A few years ago, the movement toward the expansive working of high
+steam was checked by experiments seeming to prove positive
+disadvantage to follow advance beyond a certain point. A careful
+revision of results, however, showed that this was true only with
+engines built, as was then common, in utter disregard of all the
+principles involved in such a use of steam, and of the precautions
+necessary to be taken to insure the gain which science taught us
+should follow. The hinderances are mechanical, and it is for the
+engineer to remove them.
+
+The last remark is especially applicable to the work of the engineer
+who is attempting to advance in the direction in which, as already
+intimated, an unmistakable revolution is now progressing, the
+modification of the modern steam-engine to adapt it safely and
+successfully to run at the high piston-speed, and great velocity of
+rotation which have been already attained and which must undoubtedly
+be greatly exceeded in the future. As there is no known and definite
+limit to the economical increase of speed, and as the limit set by
+practical conditions is continually being set farther back as the
+builder acquires greater skill and attains greater accuracy of
+workmanship and the power to insure greater rigidity of parts and
+durability of wearing surfaces, we must anticipate a continued and
+indefinite progress in this direction--a progress which must evidently
+be of advantage, whatever may be the direction that other changes may
+take.
+
+It is evident that this adaptation of the steam-engine to great speed
+of piston is the work now to be done by the engineer. The requisites
+to success are obvious, and may be concisely stated as follows:
+
+1. Extreme accuracy in proportions.
+
+2. Perfect accuracy in fitting parts to each other.
+
+3. Absolute symmetry of journals.
+
+4. Ample area and maximum durability of rubbing surfaces.
+
+5. Perfect certainty of an ample and continuous lubrication.
+
+6. A nicely calculated and adjusted balance of reciprocating parts.
+
+7. Security against injury by shock, whether due to the presence of
+water in the cylinder or to looseness of running parts.
+
+8. A "positive-motion" cut-off gear.
+
+9. A powerful but sensitive and accurately-working governor
+determining the degree of expansion.[118]
+
+  [118] The author is not absolutely confident on the latter point. It
+  may be found more economical and satisfactory, ultimately, to
+  determine the point of cut-off by an automatic apparatus adjusting
+  the expansion-gear _by reference to the steam-pressure_, regulating
+  the speed by attaching the governor elsewhere. The author has
+  devised several forms of apparatus of the kind referred to.
+
+10. Well-balanced valves and an easy-working valve-gear.
+
+11. Small volume of "dead-space," or "clearance," and properly
+adjusted "compression."
+
+It would seem sufficiently evident that the engine with detachable
+("drop") cut-off valve-gear must, sooner or later, become an obsolete
+type, although the substitution of springs or of steam-pressure for
+gravity in the closing of the detached valve may defer greatly this
+apparently inevitable change. The "engine of the future" will not
+probably be a "drop cut-off engine."
+
+As regards the construction of the engine as a piece of mechanism, the
+principles and practice of good engineering are precisely the same,
+whether applied in the designing of the compound or of the ordinary
+type of steam-engine. The proportioning of the two machines to each
+other in such manner as to form an effective whole, by procuring
+approximately equal amounts of work from both, is the only essential
+peculiarity of compound-engine design which calls for especial care,
+and the method of securing success in practice may be stated to be,
+for both forms of engines, as follows:
+
+1. A good design, by which is meant--
+
+_a._ Correct proportions, both in general dimensions and in
+arrangement of parts, and proper forms and sizes of details to
+withstand safely the forces which may be expected to come upon them.
+
+_b._ A general plan which embodies the recognized practice of good
+engineering.
+
+_c._ Adaptation to the specific work which it is intended to perform,
+in size and in efficiency. It sometimes happens that good practice
+dictates the use of a comparatively uneconomical design.
+
+2. Good construction, by which is meant--
+
+_a._ The use of good material.
+
+_b._ Accurate workmanship.
+
+_c._ Skillful fitting and a proper "assemblage" of parts.
+
+3. Proper connection with its work, that it may do that work under the
+conditions assumed in its design.
+
+4. Skillful management by those in whose hands it is placed.
+
+_In general_, it may be stated that, to secure maximum economical
+efficiency, steam should be worked at as high a pressure as possible,
+and the expansion should be fixed as nearly as possible at the point
+of maximum economy for that pressure. In general, the number of times
+which the volume of steam may be expanded in the standard
+single-cylinder, high-pressure engine with maximum economy, is not far
+from 1/2 sqrt(P), where P is the pressure in pounds per square inch;
+it rarely exceeds 0.75 sqrt(P). This may be exceeded in
+double-cylinder engines. It is even more disadvantageous to cut off
+too short than to "'follow' too far." With considerable expansion,
+steam-jacketing and moderate superheating should be adopted, to
+prevent excessive losses by internal condensation and reëvaporation;
+and expansion should take place in double cylinders, to avoid
+excessive weight of parts, irregularity of motion, and great loss by
+friction.
+
+To secure this vitally important economy, it is advisable to seek some
+practicable method of lining the cylinder with a non-conducting
+material. This plan, as has been seen, was adopted by Smeaton, in
+constructing Newcomen engines a century ago. Smeaton used wood on his
+pistons, and Watt tried wood as a material for steam-cylinder linings.
+That material is too perishable at temperatures now common, and no
+metal has yet been substituted, or even discovered, which answers the
+same purpose. The loss will also be reduced by increasing the speed of
+rotation and velocity of piston. Where no effectual means can be found
+of preventing contact of the steam with a good absorbent and conductor
+of heat, it will be found best to sacrifice some of the efficiency due
+to the change of state of the vapor, by superheating it and sending it
+into the cylinder at a temperature considerably exceeding that of
+saturation. With low steam and slowly-moving pistons, it is better to
+pursue the latter course than to attempt to increase the efficiency of
+the engine by greater expansion.
+
+External surfaces should be carefully covered by non-conductors and
+non-radiators, to prevent losses by conduction and radiation of heat.
+It is especially necessary to reduce back-pressure and to obtain the
+most perfect vacuum possible without overloading the air-pump, if it
+is desired to obtain the maximum efficiency by expansion, and it then
+becomes also very necessary to reduce losses by "dead-spaces" and by
+badly-adjusted valves.
+
+The piston-speed should be as great as can be sustained with safety.
+
+Good engines should not require more than W = (200/sqrt(P)) where W =
+the weight of steam per hour and per horse-power; the best practice
+gives about W = (180/sqrt(P)) in large engines with dry steam, high
+piston-speed, and good design, construction, and management.
+
+The expansion-valve gear should be simple. The point of cut-off is
+perhaps best determined by the governor. The valve should close
+rapidly, but without shock, and should be balanced, or some other
+device should be adopted to make it easy to move and free from
+liability to cutting or rapid wear.
+
+The governor should act promptly and powerfully, and should be free
+from liability to oscillate, and to thus introduce irregularities
+which are sometimes not less serious than those which the instrument
+is intended to prevent.
+
+Friction should be reduced as much as possible, and careful provision
+should be made to economize lubricants as well as fuel.
+
+The Principles of Steam-Boiler Construction are exceedingly simple;
+and although attempts are almost daily made to obtain improved
+results by varying the design and arrangement of heating-surface, the
+best boilers of nearly all makers of acknowledged standing are
+practically equal in merit, although of very diverse forms.
+
+In making boilers, the effort of the engineer should evidently be:
+
+1. To secure complete combustion of the fuel without permitting
+dilution of the products of combustion by excess of air.
+
+2. To secure as high temperature of furnace as possible.
+
+3. To so arrange heating-surfaces that, without checking draught, the
+available heat shall be most completely taken up and utilized.
+
+4. To make the form of boiler such that it shall be constructed
+without mechanical difficulty or excessive expense.
+
+5. To give it such form that it shall be durable, under the action of
+the hot gases and of the corroding elements of the atmosphere.
+
+6. To make every part accessible for cleaning and repairs.
+
+7. To make every part as nearly as possible uniform in strength, and
+in liability to loss of strength by wear and tear, so that the boiler
+when old shall not be rendered useless by local defects.
+
+8. To adopt a reasonably high "factor of safety" in proportioning
+parts.
+
+9. To provide efficient safety-valves, steam-gauges, and other
+appurtenances.
+
+10. To secure intelligent and very careful management.
+
+In securing complete combustion, the first of these desiderata, an
+ample supply of air and its thorough intermixture with the combustible
+elements of the fuel are essential; for the second--high temperature
+of furnace--it is necessary that the air-supply shall not be in excess
+of that absolutely needed to give complete combustion. The efficiency
+of a furnace in making heat available is measured by
+
+       T - T´
+  E = -------;
+      T - _t_
+
+in which E represents the ratio of heat utilized to the whole
+calorific value of the fuel, T is the furnace-temperature, T´ the
+temperature of the chimney, and _t_ that of the external air. The
+higher the furnace-temperature and the lower that of the chimney, the
+greater the proportion of heat available. It is further evident that,
+however perfect the combustion, no heat can be utilized if either the
+temperature of the chimney approximates to that of the furnace, or if
+the temperature of the furnace is reduced by dilution approximately to
+that of the boiler. Concentration of heat in the furnace is secured,
+in some cases, by special expedients, as by heating the entering air,
+or as in the Siemens gas-furnace, heating both the combustible gases
+and the supporter of combustion. Detached fire-brick furnaces have an
+advantage over the "fire-boxes" of steam-boilers in their higher
+temperature; surrounding the fire with non-conducting and highly
+heated surfaces is an effective method of securing high
+furnace-temperature.
+
+In arranging heating-surface, the effort should be to impede the
+draught as little as possible, and so to place them that the
+circulation of water within the boiler should be free and rapid at
+every part reached by the hot gases. The directions of circulation of
+water on the one side and of gas on the other side of the sheet
+should, whenever possible, be opposite. The cold water should enter
+where the cooled gases leave, and the steam should be taken off
+farthest from that point. The temperature of chimney-gases has thus
+been reduced in practice to less than 300° Fahr., and an efficiency
+equal to 0.75 to 0.80 the theoretical has been attained.
+
+The extent of heating-surface simply, in all of the best forms of
+boiler, determines the efficiency, and in them the disposition of that
+surface seldom affects it to any great extent. The area of
+heating-surface may also be varied within very wide limits without
+very greatly modifying efficiency. A ratio of 25 to 1 in flue and 30
+to 1 in tubular boilers represents the relative area of heating and
+grate surfaces as chosen in the practice of the best-known builders.
+
+The material of the boiler should be tough and ductile iron, or,
+better, a soft steel containing only sufficient carbon to insure
+melting in the crucible or on the hearth of the melting-furnace, and
+so little that no danger may exist of hardening and cracking under the
+action of sudden and great changes of temperature.
+
+Where iron is used, it is necessary to select a somewhat hard, but
+homogeneous and tough, quality for the fire-box sheets or any part
+exposed to flames.
+
+The factor of safety is invariably too low in this country, and is
+never too high in Europe. Foreign builders are more careful in this
+matter than our makers in the United States. The boiler should be
+built strong enough to bear a pressure at least six times the proposed
+working-pressure; as the boiler grows weak with age, it should be
+occasionally tested to a pressure far above the working-pressure,
+which latter should be reduced gradually to keep within the bounds of
+safety. In the United States, the factor of safety is seldom more than
+four in the new boilers, frequently much less, and even this is
+reduced practically to one and a third by the operation of our
+inspection-laws.
+
+The principles just enunciated are those generally, perhaps
+universally, accepted principles which are stated in all text-books of
+science and of steam-engineering, and are accepted by both engineers
+and men of science.
+
+These principles are correct, and the deductions which have been here
+formulated are rigidly exact, as applied to all types of heat-engine
+in use; and they lead us to the determination, in all cases, of the
+"modulus" of efficiency of the engine, i. e., to the calculation of
+the ratio of its actual efficiency to that efficiency which it would
+have, were it absolutely free from loss of heat by conduction or
+radiation, or other method of loss of heat or waste of power, by
+friction of parts or by shock.
+
+The best modern marine compound engines sometimes, as we have seen,
+consume as little as two pounds of coal per horse-power and per hour;
+but this is but about one-tenth the power derivable from the fuel,
+were all its heat thoroughly utilized. This loss may be divided thus:
+70 per cent. rejected in exhausted steam; 20 per cent. lost by
+conduction and radiation and by faults of mechanism and design; and
+only the 10 per cent. remaining is utilized. Thirty per cent. of the
+heat generated in the furnace is usually lost in the chimney, and of
+the remainder, which enters the engine, 20 per cent. at most is all
+which we can hope to save any portion of by improvements effected in
+our best existing type of steam-engine. It has already been shown how
+the engineer can best proceed in attempting this economy.
+
+The direction in which further improvement must take place in the
+standard type of engine is plainly that which shall most efficiently
+check losses by internal condensation and reëvaporation by the
+transfer of heat to and from the metal of the steam-cylinder. The
+condensation of steam doing work is evidently not a disadvantage, but,
+on the contrary, a decided advantage.
+
+A new type of engine can, if at all, probably only supersede the
+common form when engineers can employ steam of very high pressure, and
+adopt much greater range of expansion than is now usual. Great
+velocity of piston and high speed of rotation are also essential in
+the attempt to make any revolution in steam-engine construction a
+success.
+
+When a new form of steam-engine is likely to be introduced, if at all,
+can be scarcely even conjectured. It seems evident that its success is
+to be secured, if a revolution is ever to occur, by the adoption of
+high steam-pressures, of great piston speeds, by care and skill in
+design, by the use of exceptionally excellent materials of
+construction, by great perfection of workmanship, and by intelligence
+in its management.
+
+Experiment and experience will probably lead gradually to the general
+and safe employment of much higher steam-pressures and very greatly
+increased piston-speeds, and may ultimately reveal and remove all
+those difficulties which must invariably be expected to be met here,
+as in all other attempts to effect radical changes, however important
+they may be.
+
+[Illustration]
+
+
+       *       *       *       *       *
+
+
+
+
+_Scientific Publications._
+
+
+=THE HUMAN SPECIES.= By A. DE QUATREFAGES, Professor of Anthropology
+in the Museum of Natural History, Paris. 12mo, cloth, $2.00.
+
+  The work treats of the unity, origin, antiquity, and original
+  localization of the human species, peopling of the globe,
+  acclimatization, primitive man, formation of the human races, fossil
+  human races, present human races, and the physical and psychological
+  characters of mankind.
+
+
+=STUDENTS' TEXT-BOOK OF COLOR; or, MODERN CHROMATICS.= With
+Applications to Art and Industry. With 130 Original Illustrations, and
+Frontispiece in Colors. By OGDEN N. ROOD, Professor of Physics in
+Columbia College. 12mo, cloth, $2.00.
+
+  "In this interesting book Professor Rood, who, as a distinguished
+  Professor of Physics in Columbia College, United States, must be
+  accepted as a competent authority on the branch of science of which
+  he treats, deals briefly and succinctly with what may be termed the
+  scientific _rationale_ of his subject. But the chief value of his
+  work is to be attributed to the fact that he is himself an
+  accomplished artist as well as an authoritative expounder of
+  science."--_Edinburgh Review, October, 1879, in an article on "The
+  Philosophy of Color._"
+
+
+=EDUCATION AS A SCIENCE.= By ALEXANDER BAIN, LL. D. 12mo, cloth,
+$1.75.
+
+  "This work must be pronounced the most remarkable discussion of
+  educational problems which has been published in our day. We do not
+  hesitate to bespeak for it the widest circulation and the most
+  earnest attention. It should be in the hands of every school-teacher
+  and friend of education throughout the land."--_New York Sun._
+
+
+=A HISTORY OF THE GROWTH OF THE STEAM-ENGINE.= By ROBERT H. THURSTON,
+A. M., C. E., Professor of Mechanical Engineering in the Stevens
+Institute of Technology, Hoboken, N. J., etc. With 163 Illustrations,
+including 15 Portraits. 12mo, cloth, $2.50.
+
+  "Professor Thurston almost exhausts his subject; details of
+  mechanism are followed by interesting biographies of the more
+  important inventors. If, as is contended, the steam-engine is the
+  most important physical agent in civilizing the world, its history
+  is a desideratum, and the readers of the present work will agree
+  that it could have a no more amusing and intelligent historian than
+  our author."--_Boston Gazette._
+
+
+=STUDIES IN SPECTRUM ANALYSIS.= By J. NORMAN LOCKYER, F. R. S.,
+Correspondent of the Institute of France, etc. With 60 Illustrations.
+12mo, cloth, $2.50.
+
+  "The study of spectrum analysis is one fraught with a peculiar
+  fascination, and some of the author's experiments are exceedingly
+  picturesque in their results. They are so lucidly described, too,
+  that the reader keeps on, from page to page, never flagging in
+  interest in the matter before him, nor putting down the book until
+  the last page is reached."--_New York Evening Express._
+
+
+=GENERAL PHYSIOLOGY OF MUSCLES AND NERVES.= By Dr. I. ROSENTHAL,
+Professor of Physiology at the University of Erlangen. With
+seventy-five Woodcuts. ("International Scientific Series.") 12mo,
+cloth, $1.50.
+
+  "The attempt at a connected account of the general physiology of
+  muscles and nerves is, as far as I know, the first of its kind. The
+  general data for this branch of science have been gained only within
+  the past thirty years."--_Extract from Preface._
+
+
+=SIGHT=: An Exposition of the Principles of Monocular and Binocular
+Vision By JOSEPH LE CONTE, LL. D., author of "Elements of Geology";
+"Religion and Science"; and Professor of Geology and Natural History
+in the University of California. With numerous Illustrations. 12mo,
+cloth, $1.50.
+
+  "It is pleasant to find an American book which can rank with the
+  very best of foreign works on this subject. Professor Le Conte has
+  long been known as an original investigator in this department; all
+  that he gives us is treated with a master-hand."--_The Nation._
+
+
+=ANIMAL LIFE=, as affected by the Natural Conditions of Existence. By
+KARL SEMPER, Professor of the University of Würzburg. With 2 Maps and
+106 Woodcuts, and Index. 12mo, cloth, $2.00.
+
+  "This is in many respects one of the most interesting contributions
+  to zoölogical literature which has appeared for some
+  time."--_Nature._
+
+
+=THE ATOMIC THEORY.= By AD. WURTZ, Membre de l'Institut; Doyen
+Honoraire de la Faculté de Médecine; Professeur à la Faculté des
+Sciences de Paris. Translated by E. CLEMINSHAW, M. A., F. C. S., F. I.
+C., Assistant Master at Sherborne School. 12mo, cloth, $1.50.
+
+  "There was need for a book like this, which discusses the atomic
+  theory both in its historic evolution and in its present form. And
+  perhaps no man of this age could have been selected so able to
+  perform the task in a masterly way as the illustrious French
+  chemist, Adolph Wurtz. It is impossible to convey to the reader, in
+  a notice like this, any adequate idea of the scope, lucid
+  instructiveness, and scientific interest of Professor Wurtz's book.
+  The modern problems of chemistry, which are commonly so obscure from
+  imperfect exposition, are here made wonderfully clear and
+  attractive."--_The Popular Science Monthly._
+
+
+=THE CRAYFISH.= An Introduction to the Study of Zoölogy. By Professor
+T. H. HUXLEY, F. R. S. With 82 Illustrations. 12mo, cloth, $1.75.
+
+  "Whoever will follow these pages, crayfish in hand, and will try to
+  verify for himself the statements which they contain, will find
+  himself brought face to face, with all the great zoölogical
+  questions which excite so lively an interest at the present day."
+
+  "The reader of this valuable monograph will lay it down with a
+  feeling of wonder at the amount and variety of matter which has been
+  got out of so seemingly slight and unpretending a
+  subject."--_Saturday Review._
+
+
+=SUICIDE=: An Essay In Comparative Moral Statistics. By HENRY
+MORSELLI, Professor of Psychological Medicine in Royal University,
+Turin. 12mo, Cloth, $1.75.
+
+  "Suicide" is a scientific inquiry, on the basis of the statistical
+  method, into the laws of suicidal phenomena. Dealing with the
+  subject as a branch of social science, it considers the increase of
+  suicide in different countries, and the comparison of nations,
+  races, and periods in its manifestation. The influences of age, sex,
+  constitution, climate, season, occupation, religion, prevailing
+  ideas, the elements of character, and the tendencies of
+  civilization, are comprehensively analyzed in their bearing upon the
+  propensity to self-destruction. Professor Morselli is an eminent
+  European authority on this subject. It is accompanied by colored
+  maps illustrating pictorially the results of statistical inquiries.
+
+
+=VOLCANOES: What they Are and what they Teach.= By J. W. JUDD,
+Professor of Geology in the Royal School of Mines (London). With
+Ninety-six Illustrations. 12mo. Cloth, $2.00.
+
+  "In no field has modern research been more fruitful than in that of
+  which Professor Judd gives a popular account in the present volume.
+  The great lines of dynamical, geological, and meteorological inquiry
+  converge upon the grand problem of the interior constitution of the
+  earth, and the vast influence of subterranean agencies.... His book
+  is very far from being a mere dry description of volcanoes and their
+  eruptions; it is rather a presentation of the terrestrial facts and
+  laws with which volcanic phenomena are associated."--_Popular
+  Science Monthly._
+
+  "The volume before us is one of the pleasantest science manuals we
+  have read for some time."--_Athenæum._
+
+  "Mr. Judd's summary is so full and so concise that it is almost
+  impossible to give a fair idea in a short review."--_Pall Mall
+  Gazette._
+
+
+=THE SUN.= By C. A. YOUNG, Ph. D., LL. D., Professor of Astronomy in
+the College of New Jersey. With numerous Illustrations. 12mo. Cloth,
+$2.00.
+
+  "Professor Young is an authority on 'The Sun,' and writes from
+  intimate knowledge. He has studied that great luminary all his life,
+  invented and improved instruments for observing it, gone to all
+  quarters of the world in search of the best places and opportunities
+  to watch it, and has contributed important discoveries that have
+  extended our knowledge of it.
+
+  "It would take a cyclopædia to represent all that has been done
+  toward clearing up the solar mysteries. Professor Young has
+  summarized the information, and presented it in a form completely
+  available for general readers. There is no rhetoric in his book; he
+  trusts the grandeur of his theme to kindle interest and impress the
+  feelings. His statements are plain, direct, clear, and condensed,
+  though ample enough for his purpose, and the substance of what is
+  generally wanted will be found accurately given in his
+  pages."--_Popular Science Monthly._
+
+
+=ILLUSIONS: A Psychological Study.= By JAMES SULLY, author of
+"Sensation and Intuition," etc. 12mo. Cloth. $1.50.
+
+  This volume takes a wide survey of the field of error, embracing in
+  its view not only the illusions commonly regarded as of the nature
+  of mental aberrations or hallucinations, but also other illusions
+  arising from that capacity for error which belongs essentially to
+  rational human nature. The author has endeavored to keep to a
+  strictly scientific treatment--that is to say, the description and
+  classification of acknowledged errors, and the exposition of them by
+  a reference to their psychical and physical conditions.
+
+  "This is not a technical work, but one of wide popular interest, in
+  the principles and results of which every one is concerned. The
+  illusions of perception of the senses and of dreams are first
+  considered, and then the author passes to the illusions of
+  introspection, errors of insight, illusions of memory, and illusions
+  of belief. The work is a noteworthy contribution to the original
+  progress of thought, and may be relied upon as representing the
+  present state of knowledge on the important subject to which it is
+  devoted."--_Popular Science Monthly._
+
+
+=THE BRAIN AND ITS FUNCTIONS.= By J. LUYS, Physician to the Hospice de
+la Salpêtrière. With Illustrations. 12mo. Cloth, $1.50.
+
+  "No living physiologist is better entitled to speak with authority
+  upon the structure and functions of the brain than Dr. Luys. His
+  studies on the anatomy of the nervous system are acknowledged to be
+  the fullest and most systematic ever undertaken. Dr. Luys supports
+  his conclusions not only by his own anatomical researches, but also
+  by many functional observations of various other physiologists,
+  including of course Professor Ferrier's now classical
+  experiments."--_St. James's Gazette._
+
+  "Dr. Luys, at the head of the great French Insane Asylum, is one of
+  the most eminent and successful investigators of cerebral science
+  now living; and he has given unquestionably the clearest and most
+  interesting brief account yet made of the structure and operations
+  of the brain. We have been fascinated by this volume more than by
+  any other treatise we have yet seen on the machinery of sensibility
+  and thought; and we have been instructed not only by much that is
+  new, but by many sagacious practical hints such as it is well for
+  everybody to understand."--_The Popular Science Monthly._
+
+
+=THE CONCEPTS AND THEORIES OF MODERN PHYSICS.= By J. B. STALLO. 12mo.
+Cloth, $1.75.
+
+  "Judge Stallo's work is an inquiry into the validity of those
+  mechanical conceptions of the universe which are now held as
+  fundamental in physical science. He takes up the leading modern
+  doctrines which are based upon this mechanical conception, such as
+  the atomic constitution of matter, the kinetic theory of gases, the
+  conservation of energy, the nebular hypothesis, and other views, to
+  find how much stands upon solid empirical ground, and how much rests
+  upon metaphysical speculation. Since the appearance of Dr. Draper's
+  'Religion and Science,' no book has been published in the country
+  calculated to make so deep an impression on thoughtful and educated
+  readers as this volume.... The range and minuteness of the author's
+  learning, the acuteness of his reasoning, and the singular precision
+  and clearness of his style, are qualities which very seldom have
+  been jointly exhibited in a scientific treatise."--_New York Sun._
+
+
+=THE FORMATION OF VEGETABLE MOULD, THROUGH THE ACTION OF WORMS, WITH
+OBSERVATIONS ON THEIR HABITS.= By CHARLES DARWIN, LL. D., F. R. S.,
+author of "On the Origin of Species," etc., etc. With Illustrations.
+12mo, cloth. Price, $1.50.
+
+  "Mr. Darwin's little volume on the habits and instincts of
+  earth-worms is no less marked than the earlier or more elaborate
+  efforts of his genius by freshness of observation, unfailing power
+  of interpreting and correlating facts, and logical vigor in
+  generalizing upon them. The main purpose of the work is to point out
+  the share which worms have taken in the formation of the layer of
+  vegetable mould which covers the whole surface of the land in every
+  moderately humid country. All lovers of nature will unite in
+  thanking Mr. Darwin for the new and interesting light he has thrown
+  upon a subject so long overlooked, yet so full of interest and
+  instruction, as the structure and the labors of the
+  earth-worm."--_Saturday Review._
+
+  "Respecting worms as among the most useful portions of animate
+  nature, Dr. Darwin relates, in this remarkable book, their structure
+  and habits, the part they have played in the burial of ancient
+  buildings and the denudation of the land, in the disintegration of
+  rocks, the preparation of soil for the growth of plants, and in the
+  natural history of the world."--_Boston Advertiser._
+
+
+=ANTS, BEES, AND WASPS.= A Record of Observations on the Habits of the
+Social Hymenoptera. By Sir JOHN LUBBOCK, Bart., M. P., F. R. S., etc.,
+author of "Origin of Civilization, and the Primitive Condition of
+Man," etc., etc. With Colored Plates. 12mo, cloth, $2.00.
+
+  "This volume contains the record of various experiments made with
+  ants, bees, and wasps during the last ten years, with a view to test
+  their mental condition and powers of sense. The principal point in
+  which Sir John's mode of experiment differs from those of Huber,
+  Forel, McCook, and others, is that he has carefully watched and
+  marked particular insects, and has had their nests under observation
+  for long periods--one of his ants' nests having been under constant
+  inspection ever since 1874. His observations are made principally
+  upon ants because they show more power and flexibility of mind; and
+  the value of his studies is that they belong to the department of
+  original research."
+
+  "We have no hesitation in saying that the author has presented us
+  with the most valuable series of observations on a special subject
+  that has ever been produced, charmingly written, full of logical
+  deductions, and, when we consider his multitudinous engagements, a
+  remarkable illustration of economy of time. As a contribution to
+  insect psychology, it will be long before this book finds a
+  parallel."--_London Athenæum._
+
+
+=DISEASES OF MEMORY=: An Essay in the Positive Psychology. By TH.
+RIBOT, author of "Heredity," etc. Translated from the French by
+William Huntington Smith. 12mo, cloth, $1.50.
+
+  "M. Ribot reduces diseases of memory to law, and his treatise is of
+  extraordinary interest."--_Philadelphia Press._
+
+  "Not merely to scientific, but to all thinking men, this volume will
+  prove intensely interesting."--_New York Observer._
+
+  "M. Ribot has bestowed the most painstaking attention upon his
+  theme, and numerous examples of the conditions considered greatly
+  increase the value and interest of the volume."--_Philadelphia North
+  American._
+
+  "To the general reader the work is made entertaining by many
+  illustrations connected with such names as Linnæus, Newton, Sir
+  Walter Scott, Horace Vernet, Gustave Doré, and many
+  others."--_Harrisburg Telegraph._
+
+  "The whole subject is presented with a Frenchman's vivacity of
+  style."--_Providence Journal._
+
+  "It is not too much to say that in no single work have so many
+  curious cases been brought together and interpreted in a scientific
+  manner."--_Boston Evening Traveller._
+
+
+=MYTH AND SCIENCE.= By TITO VIGNOLI. 12mo, cloth, price, $1.50.
+
+  "His book is ingenious; ... his theory of how science gradually
+  differentiated from and conquered myth is extremely well wrought
+  out, and is probably in essentials correct."--_Saturday Review._
+
+  "The book is a strong one, and far more interesting to the general
+  reader than its title would indicate. The learning, the acuteness,
+  the strong reasoning power, and the scientific spirit of the author,
+  command admiration."--_New York Christian Advocate._
+
+  "An attempt made, with much ability and no small measure of success,
+  to trace the origin and development of the myth. The author has
+  pursued his inquiry with much patience and ingenuity, and has
+  produced a very readable and luminous treatise."--_Philadelphia
+  North American._
+
+  "It is a curious if not startling contribution both to psychology
+  and to the early history of man's development."--_New York World._
+
+
+=MAN BEFORE METALS.= By N. JOLY, Professor at the Science Faculty of
+Toulouse; Correspondent of the Institute. With 148 Illustrations,
+12mo. Cloth, $1.75.
+
+  "The discussion of man's origin and early history, by Professor De
+  Quatrefages, formed one of the most useful volumes in the
+  'International Scientific Series,' and the same collection is now
+  further enriched by a popular treatise on paleontology, by M. N.
+  Joly, Professor in the University of Toulouse. The title of the
+  book, 'Man before Metals,' indicates the limitations of the writer's
+  theme. His object is to bring together the numerous proofs,
+  collected by modern research, of the great age of the human race,
+  and to show us what man was, in respect of customs, industries, and
+  moral or religious ideas, before the use of metals was known to
+  him."--_New York Sun._
+
+  "An interesting, not to say fascinating volume."--_New York
+  Churchman._
+
+
+=ANIMAL INTELLIGENCE.= By GEORGE J. ROMANES, F. R. S., Zoölogical
+Secretary of the Linnæan Society, etc. 12mo. Cloth, $1.75.
+
+  "My object in the work as a whole is twofold: First, I have thought
+  it desirable that there should be something resembling a text-book
+  of the facts of Comparative Psychology, to which men of science, and
+  also metaphysicians, may turn whenever they have occasion to
+  acquaint themselves with the particular level of intelligence to
+  which this or that species of animal attains. My second and much
+  more important object is that of considering the facts of animal
+  intelligence in their relation to the theory of descent."--_From the
+  Preface._
+
+  "Unless we are greatly mistaken, Mr. Romanes's work will take its
+  place as one of the most attractive volumes of the 'International
+  Scientific Series.' Some persons may, indeed, be disposed to say
+  that it is too attractive, that it feeds the popular taste for the
+  curious and marvelous without supplying any commensurate discipline
+  in exact scientific reflection; but the author has, we think, fully
+  justified himself in his modest preface. The result is the
+  appearance of a collection of facts which will be a real boon to the
+  student of Comparative Psychology for this is the first attempt to
+  present systematically well-assured observations on the mental life
+  of animals."--_Saturday Review._
+
+  "The author believes himself, not without ample cause, to have
+  completely bridged the supposed gap between instinct and reason by
+  the authentic proofs here marshaled of remarkable intelligence in
+  some of the higher animals. It is the seemingly conclusive evidence
+  of reasoning; powers furnished by the adaptation of means to ends in
+  cases which can not be explained on the theory of inherited aptitude
+  or habit."--_New York Sun._
+
+
+=THE SCIENCE OF POLITICS.= By SHELDON AMOS, M. A., author of "The
+Science of Law," etc. 12mo. Cloth, $1.75.
+
+  "To the political student and the practical statesman it ought to be
+  of great value."--_New York Herald._
+
+  "The author traces the subject from Plato and Aristotle in Greece,
+  and Cicero in Rome, to the modern schools in the English field, not
+  slighting the teachings of the American Revolution or the lessons of
+  the French Revolution of 1793. Forms of government, political terms,
+  the relation of law, written and unwritten, to the subject, a
+  codification from Justinian to Napoleon in France and Field in
+  America, are treated as parts of the subject in hand. Necessarily
+  the subjects of executive and legislative authority, police, liquor,
+  and land laws are considered, and the question ever growing in
+  importance in all countries, the relations of corporations to the
+  state."--_New York Observer._
+
+
+=THE FUNDAMENTAL CONCEPTS OF MODERN PHILOSOPHIC THOUGHT, CRITICALLY
+AND HISTORICALLY CONSIDERED.= By RUDOLPH EUCKEN, Ph. D., Professor in
+Jena. With an Introduction by NOAH PORTER, President of Yale College.
+One vol., 12mo, 304 pages. Cloth. Price, $1.75.
+
+  President Porter declares of this work that "there are few books
+  within his knowledge which are better fitted to aid the student who
+  wishes to acquaint himself with the course of modern speculation and
+  scientific thinking, and to form an intelligent estimate of most of
+  the current theories."
+
+
+=MIND IN THE LOWER ANIMALS IN HEALTH AND DISEASE.= By W. LAUDER
+LINDSAY, M. D., F. R. S. E., etc. 2 vols., 8vo. Cloth, $4.00.
+
+  "The author of this work, which, regarded merely as an accumulation
+  of verified and classified facts, is a unique and precious
+  contribution to the data of comparative psychology, claims that he
+  entered on his inquiry without any theory to defend, support, or
+  illustrate. We are bound to say that, while his general conclusions
+  are boldly and continually avowed, his claim of fairness and caution
+  is justified by his method of examining particular phenomena; that
+  he seems willing at all times to renounce any impression or belief
+  which is shown to be scientifically untenable."--_New York Sun._
+
+  "In this work--two volumes of over 500 pages--Dr. Lindsay marshals a
+  proportionately large number of facts against those philosophers who
+  maintain that the intelligence of man differs in kind and not simply
+  in degree from that of the lower animals. It is one purpose of his
+  book to show that the main differences between man and the lower
+  animals exist rather in their physical than in their mental
+  structure. In this way of thinking, all animals possess not the
+  semblance of, but the true substance of mind and will."--_New York
+  World._
+
+  "So far as we are aware there has been no treatise upon the subject
+  of animal intelligence so broad in its foundations, so well
+  considered, or so scientific in its methods of inquiry, as that
+  which has been prepared by Dr. W. Lauder Lindsay in two large
+  volumes, the first being devoted to a study of animal mind in
+  health, and the second to animal mind in disease. We may safely say
+  that his work is, in some respects, the most important essay of the
+  kind that has yet been undertaken. His observations have been
+  supplemented by a thorough mastery of the history and literature of
+  the subject, and hence his conclusions rest upon the broadest
+  possible foundation of safe induction. There is a good analytical
+  index to the book, as there ought to be to every work of the
+  kind."--_New York Evening Post._
+
+
+=THE ELEMENTARY PRINCIPLES OF SCIENTIFIC AGRICULTURE.= By N. T.
+LUPTON, LL. D., Professor of Chemistry in Vanderbilt University,
+Nashville, Tenn. 18mo. Cloth. Price, 45 cents.
+
+
+=A GLOSSARY OF BIOLOGICAL, ANATOMICAL, AND PHYSIOLOGICAL TERMS.= By
+THOMAS DUNMAN. Small 8vo. Cloth. 161 pages. Price, $1.00.
+
+  "It has been the author's task to furnish here a small and
+  convenient but very complete glossary of those terms; and he has
+  done this so well, both in his choice of terms for definition and in
+  his clear exposition of their etymological and technical meaning, as
+  to leave nothing to be desired in this direction."--_New York
+  Evening Post._
+
+
+   _For sale by all booksellers, or any work sent by mail, post-paid,
+                         on receipt of price._
+
+                      D. APPLETON & CO., Publishers,
+                     1, 3, & 5 Bond Street, New York.
+
+
+
+
+SCIENTIFIC LECTURES AND ESSAYS.
+
+
+=Popular Lectures on Scientific Subjects.= By H. HELMHOLTZ, Professor
+of Physics in the University of Berlin. First Series. Translated by E.
+ATKINSON, Ph. D., F. C. S. With an Introduction by Professor TYNDALL.
+With 51 Illustrations. 12mo. Cloth, $2.00.
+
+  _CONTENTS._--On the Relation of Natural Science to Science in
+  General.--On Goethe's Scientific Researches.--On the Physiological
+  Causes of Harmony in Music--Ice and Glaciers.--Interaction of the
+  Natural Forces.--The Recent Progress of the Theory of Vision.--The
+  Conservation of Force.--Aim and Progress of Physical Science.
+
+
+=Popular Lectures on Scientific Subjects.= By H. HELMHOLTZ. Second
+Series. 12mo. Cloth, $1.50.
+
+  _CONTENTS._--Gustav Magnus.--In Memoriam.--The Origin and
+  Significance of Geometrical Axioms.--Relation of Optics to
+  Painting.--Origin of the Planetary System.--On Thought in
+  Medicine.--Academic Freedom in German Universities.
+
+  "Professor Helmholtz's second series of 'Popular Lectures on
+  Scientific Subjects' forms a volume of singular interest and value.
+  He who anticipates a dry record of facts or a sequence of immature
+  generalization will find himself happily mistaken. In style and
+  method these discourses are models of excellence, and, since they
+  come from a man whose learning and authority are beyond dispute,
+  they may be accepted as presenting the conclusions of the best
+  thought of the times in scientific fields."--_Boston Traveler._
+
+
+=Science and Culture, and other Essays.= By Professor T. H. HUXLEY, F.
+R. S. 12mo. Cloth, $1.50.
+
+  "Of the essays that have been collected by Professor Huxley in this
+  volume, the first four deal with some aspect of education. Most of
+  the remainder are expositions of the results of biological research,
+  and, at the same time, illustrations of the history of scientific
+  ideas. Some of these are among the most interesting of Professor
+  Huxley's contributions to the literature of science."--_London
+  Academy._
+
+  "It is refreshing to be brought into converse with one of the most
+  vigorous and acute thinkers of our time, who has the power of
+  putting his thoughts into language so clear and forcible."--_London
+  Spectator._
+
+
+=Scientific Culture, and other Essays.= By JOSIAH PARSONS COOKE,
+Professor of Chemistry and Mineralogy in Harvard College. 12mo. Cloth,
+$1.00.
+
+  These essays are an outcome of a somewhat large experience in
+  teaching physical science to college students. Cambridge,
+  Massachusetts, early set the example of making the student's own
+  observations in the laboratory or cabinet the basis of all teaching,
+  either in experimental or natural history science; and this example
+  has been generally followed. "But in most centers of education,"
+  writes Professor Cooke, "the old traditions so far survive that the
+  great end of scientific culture is lost in attempting to conform
+  even laboratory instruction to the old academic methods of
+  recitations and examinations. To point out this error, and to claim
+  for science-teaching its appropriate methods, was one object of
+  writing these essays."
+
+
+       _For sale by all booksellers; or sent by mail, post-paid,
+                       on receipt of price._
+
+          New York: D. APPLETON & CO., 1, 3, & 5 Bond Street.
+
+
+
+
+
+End of the Project Gutenberg EBook of A History of the Growth of the
+Steam-Engine, by Robert H. Thurston
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+<pre>
+
+The Project Gutenberg EBook of A History of the Growth of the Steam-Engine, by 
+Robert H. Thurston
+
+This eBook is for the use of anyone anywhere at no cost and with
+almost no restrictions whatsoever.  You may copy it, give it away or
+re-use it under the terms of the Project Gutenberg License included
+with this eBook or online at www.gutenberg.org
+
+
+Title: A History of the Growth of the Steam-Engine
+
+Author: Robert H. Thurston
+
+Release Date: April 19, 2011 [EBook #35916]
+
+Language: English
+
+Character set encoding: ISO-8859-1
+
+*** START OF THIS PROJECT GUTENBERG EBOOK STEAM ***
+
+
+
+
+Produced by Chris Curnow, Harry Lamé and the Online
+Distributed Proofreading Team at http://www.pgdp.net (This
+file was produced from images generously made available
+by The Internet Archive)
+
+
+
+
+
+
+</pre>
+
+
+<hr class="c40" />
+<div class="notebox">
+<p class="center"><b>Transcriber's Notes:</b></p>
+<p>Some minor typographical errors have been corrected. Where necessary, illustrations have been edited to include
+the reference letters used in the text or to increase their visibility.</p>
+<p>Full notes can be found <a href="#TNotes">here</a>.</p>
+</div>
+<hr class="c40" />
+
+<div class="figcenter"><img src="images/illocover.jpg" alt="Cover" /></div>
+
+<hr class="c40" />
+<div class="ind20">
+<h2>THE INTERNATIONAL SCIENTIFIC SERIES.</h2>
+
+<h2>VOLUME XXIV.</h2>
+<hr class="c40" />
+<span class='pagenum'><a name="Page_01" id="Page_01">[1]</a></span>
+
+<div class="bbox">
+<h3>THE</h3>
+<h2>INTERNATIONAL SCIENTIFIC SERIES.</h2>
+<hr class="c05" />
+<p class="center smcap">Each book complete in One Volume, 12mo, and bound in Cloth.</p>
+<hr class="c05" />
+
+<p>1. FORMS OF WATER: A Familiar Exposition of the Origin and Phenomena
+of Glaciers. By <span class="smcap">J. Tyndall</span>, LL. D., F. R. S. With 25
+Illustrations. $1.50.</p>
+
+<p>2. <a href="http://www.gutenberg.org/ebooks/4350">PHYSICS AND POLITICS; Or, Thoughts on the Application of the
+Principles of &#8220;Natural Selection&#8221; and &#8220;Inheritance&#8221; to Political
+Society</a>. By <span class="smcap">Walter Bagehot</span>. $1.50.</p>
+
+<p>3. FOODS. By <span class="smcap">Edward Smith</span>, M. D., LL. B., F. R. S. With numerous
+Illustrations. $1.75.</p>
+
+<p>4. MIND AND BODY: The Theories of their Relation. By <span class="smcap">Alexander
+Bain</span>, LL. D. With 4 Illustrations. $1.50.</p>
+
+<p>5. THE STUDY OF SOCIOLOGY. By <span class="smcap">Herbert Spencer</span>. $1.50.</p>
+
+<p>6. THE NEW CHEMISTRY. By Professor <span class="smcap">J. P. Cooke</span>, of Harvard
+University. With 31 Illustrations. $2.00.</p>
+
+<p>7. ON THE CONSERVATION OF ENERGY. By <span class="smcap">Balfour Stewart</span>,
+M. A., LL. D., F. R. S. With 14 Illustrations. $1.50.</p>
+
+<p>8. ANIMAL LOCOMOTION; or, Walking, Swimming, and Flying. By
+<span class="smcap">J. B. Pettigrew</span>, M. D., F. R. S., etc. With 130 Illustrations. $1.75.</p>
+
+<p>9. RESPONSIBILITY IN MENTAL DISEASE. By <span class="smcap">Henry Maudsley</span>, M. D. $1.50.</p>
+
+<p>10. THE SCIENCE OF LAW. By Professor <span class="smcap">Sheldon Amos</span>. $1.75.</p>
+
+<p>11. ANIMAL MECHANISM: A Treatise on Terrestrial and A&euml;rial Locomotion.
+By Professor <span class="smcap">E. J. Marey</span>. With 117 Illustrations. $1.75.</p>
+
+<p>12. <a href="http://www.gutenberg.org/ebooks/1185">THE HISTORY OF THE CONFLICT BETWEEN RELIGION
+AND SCIENCE</a>. By <span class="smcap">J. W. Draper</span>, M. D., LL. D. $1.75.</p>
+
+<p>13. THE DOCTRINE OF DESCENT AND DARWINISM. By Professor
+<span class="smcap">Oscar Schmidt</span> (Strasburg University). With 26 Illustrations.
+$1.50.</p>
+
+<p>14. THE CHEMICAL EFFECTS OF LIGHT AND PHOTOGRAPHY.
+By Dr. <span class="smcap">Hermann Vogel</span> (Polytechnic Academy of Berlin). Translation
+thoroughly revised. With 100 Illustrations. $2.00.</p>
+
+<p><span class='pagenum'><a name="Page_02" id="Page_02">[2]</a></span>
+15. <a href="http://www.gutenberg.org/ebooks/30181">FUNGI: Their Nature, Influences, Uses, etc</a>.
+By <span class="smcap">M. C. Cooke</span>, M. A.,
+LL. D. Edited by the Rev. M. J. Berkeley, M. A., F. L. S. With
+109 Illustrations. $1.50.</p>
+
+<p>16. THE LIFE AND GROWTH OF LANGUAGE. By Professor
+<span class="smcap">William Dwight Whitney</span>, of Yale College. $1.50.</p>
+
+<p>17. MONEY AND THE MECHANISM OF EXCHANGE. By <span class="smcap">W.
+Stanley Jevons</span>, M. A., F. R. S. $1.75.</p>
+
+<p>18. THE NATURE OF LIGHT, with a General Account of Physical
+Optics. By Dr. <span class="smcap">Eugene Lommel</span>. With 188 Illustrations and a
+Table of Spectra in Chromo-lithography. $2.00.</p>
+
+<p>19. ANIMAL PARASITES AND MESSMATES. By Monsieur <span class="smcap">Van
+Beneden</span>. With 83 Illustrations. $1.50.</p>
+
+<p>20. FERMENTATION. By Professor <span class="smcap">Sch&uuml;tzenberger</span>. With 28 Illustrations.
+$1.50.</p>
+
+<p>21. THE FIVE SENSES OF MAN. By Professor <span class="smcap">Bernstein</span>. With 91
+Illustrations. $1.75.</p>
+
+<p>22. THE THEORY OF SOUND IN ITS RELATION TO MUSIC. By
+Professor <span class="smcap">Pietro Blaserna</span>. With numerous Illustrations. $1.50.</p>
+
+<p>23. STUDIES IN SPECTRUM ANALYSIS. By <span class="smcap">J. Norman Lockyer</span>,
+F. R. S. With 6 Photographic Illustrations of Spectra, and numerous
+Engravings on Wood. $2.50.</p>
+
+<p>24. A HISTORY OF THE GROWTH OF THE STEAM-ENGINE.
+By Professor <span class="smcap">E. H. Thurston</span>. With 163 Illustrations. $2.50.</p>
+
+<p>25. EDUCATION AS A SCIENCE. By <span class="smcap">Alexander Bain</span>, LL. D.
+$1.75.</p>
+
+<p>26. STUDENTS&#8217; TEXT-BOOK OF COLOR; Or, Modern Chromatics.
+With Applications to Art and Industry. By Professor <span class="smcap">Ogden N.
+Rood</span>, Columbia College. New edition. With 130 Illustrations.
+$2.00.</p>
+
+<p>27. THE HUMAN SPECIES. By Professor <span class="smcap">A. de Quatrefages</span>, Membre
+de l&#8217;Institut. $2.00.</p>
+
+<p>28. THE CRAYFISH: An Introduction to the Study of Zoology. By <span class="smcap">T.
+H. Huxley</span>, F. R. S. With 82 Illustrations. $1.75.</p>
+
+<p>29. THE ATOMIC THEORY. By Professor <span class="smcap">A. Wurtz</span>. Translated by
+E. Cleminshaw, F. C. S. $1.50.</p>
+
+<p><span class='pagenum'><a name="Page_03" id="Page_03">[3]</a></span>
+30. ANIMAL LIFE AS AFFECTED BY THE NATURAL CONDITIONS
+OF EXISTENCE. By <span class="smcap">Karl Semper</span>. With 2 Maps and
+106 Woodcuts. $2.00.</p>
+
+<p>31. SIGHT: An Exposition of the Principles of Monocular and Binocular
+Vision. By <span class="smcap">Joseph Le Conte</span>, LL. D. With 132 Illustrations.
+$1.50.</p>
+
+<p>32. GENERAL PHYSIOLOGY OF MUSCLES AND NERVES. By
+Professor <span class="smcap">J. Rosenthal</span>. With 75 Illustrations. $1.50.</p>
+
+<p>33. <a href="http://www.gutenberg.org/ebooks/17815">ILLUSIONS: A Psychological Study</a>.
+By <span class="smcap">James Sully</span>. $1.50.</p>
+
+<p>34. THE SUN. By <span class="smcap">C. A. Young</span>, Professor of Astronomy in the College
+of New Jersey. With numerous Illustrations. $2.00.</p>
+
+<p>35. VOLCANOES: What they Are and what they Teach. By <span class="smcap">John W.
+Judd</span>, F. R. S., Professor of Geology in the Royal School of Mines.
+With 96 Illustrations. $2.00.</p>
+
+<p>36. SUICIDE: An Essay in Comparative Moral Statistics. By <span class="smcap">Henry
+Morselli</span>, M. D., Professor of Psychological Medicine, Royal University,
+Turin. $1.75.</p>
+
+<p>37. <a href="http://www.gutenberg.org/ebooks/2355">THE FORMATION OF VEGETABLE MOULD, THROUGH THE
+ACTION OF WORMS. With Observations on their Habits</a>. By
+<span class="smcap">Charles Darwin</span>, LL. D., F. R. S. With Illustrations. $1.50.</p>
+
+<p>38. THE CONCEPTS AND THEORIES OF MODERN PHYSICS. By
+<span class="smcap">J. B. Stallo</span>. $1.75.</p>
+
+<p>39. THE BRAIN AND ITS FUNCTIONS. By <span class="smcap">J. Luys</span>. $1.50.</p>
+
+<p>40. <a href="http://www.gutenberg.org/ebooks/17802">MYTH AND SCIENCE</a>. By <span class="smcap">Tito Vignoli</span>. $1.50.</p>
+
+<p>41. DISEASES OF MEMORY: An Essay in the Positive Psychology.
+By <span class="smcap">Th. Ribot</span>, author of &#8220;Heredity.&#8221; $1.50.</p>
+
+<p>42. ANTS, BEES, AND WASPS. A Record of Observations of the
+Habits of the Social Hymenoptera. By Sir <span class="smcap">John Lubbock</span>, Bart.,
+F. R. S., D. C. L., LL. D., etc. $2.00.</p>
+
+<p>43. SCIENCE OF POLITICS. By <span class="smcap">Sheldon Amos</span>. $1.75.</p>
+
+<p>44. ANIMAL INTELLIGENCE. By <span class="smcap">George J. Romanes</span>. $1.75.</p>
+
+<p>45. MAN BEFORE METALS. By <span class="smcap">N. Joly</span>, Correspondent of the Institute.
+With 148 Illustrations. $1.75.</p>
+
+<p><span class='pagenum'><a name="Page_04" id="Page_04">[4]</a></span>46. THE ORGANS OF SPEECH AND THEIR APPLICATION IN
+THE FORMATION OF ARTICULATE SOUNDS. By <span class="smcap">G. H.
+von Meyer</span>, Professor in Ordinary of Anatomy at the University of
+Z&uuml;rich. With 47 Woodcuts. $1.75.</p>
+
+<p>47. FALLACIES: A View of Logic from the Practical Side. By <span class="smcap">Alfred
+Sidgwick</span>, B. A., Oxon. $1.75.</p>
+
+<p>48. ORIGIN OF CULTIVATED PLANTS. By <span class="smcap">Alphonse de Candolle</span>.
+$2.00.</p>
+
+<p>49. JELLY-FISH, STAR-FISH, AND SEA-URCHINS. Being a Research
+on Primitive Nervous Systems. By <span class="smcap">George J. Romanes</span>.
+$1.75.</p>
+
+<p>50. THE COMMON SENSE OF THE EXACT SCIENCES. By the
+late <span class="smcap">William Kingdon Clifford</span>. $1.50.</p>
+
+<p>51. PHYSICAL EXPRESSION: Its Modes and Principles. By <span class="smcap">Francis
+Warner</span>, M. D., Assistant Physician, and Lecturer on Botany to the
+London Hospital, etc. With 51 Illustrations. $1.75.</p>
+
+<p>52. ANTHROPOID APES. By <span class="smcap">Robert Hartmann</span>, Professor in the
+University of Berlin. With 63 Illustrations. $1.75.</p>
+
+<p>53. THE MAMMALIA IN THEIR RELATION TO PRIMEVAL
+TIMES. By <span class="smcap">Oscar Schmidt</span>. $1.50.</p>
+
+<hr class="c05" />
+<p class="center">New York: D. APPLETON &amp; CO., 1, 3, &amp; 5 Bond Street.</p>
+<hr class="c40" />
+</div>
+</div>
+
+<div class="figcenter"><a name="Frontispiece" id="Frontispiece"></a>
+<img src="images/illo009.png" alt="Frontispiece" width="350" height="539" />
+<p class="caption"><span class="smcap">The Grecian Idea of the Steam-Engine.</span></p></div>
+<hr class="c40" />
+
+<p class='pagenum'><a name="Page_i" id="Page_i">[i]</a></p>
+
+<h3>THE INTERNATIONAL SCIENTIFIC SERIES.</h3>
+<hr class="c05" />
+
+<h1>A HISTORY</h1>
+<h3>OF THE</h3>
+<h1>GROWTH OF THE STEAM-ENGINE.</h1>
+
+<h3>BY</h3>
+
+<h2>ROBERT H. THURSTON, A. M., C. E.,</h2>
+
+<p class="center fsize80">PROFESSOR OF ENGINEERING STEVENS INSTITUTE OF TECHNOLOGY, PAST PRESIDENT<br />
+AMERICAN SOCIETY MECHANICAL ENGINEERS, MEMBER OF SOCIETY OF CIVIL<br />
+ENGINEERS, SOCI&Eacute;T&Eacute; DES ING&Eacute;NIEURS CIVILS, VEREIN DEUTSCHE<br />
+INGENIEURE, OESTERREICHISCHER INGENIEUR- UND<br />
+ARCHITEKTEN-VEREIN; ASSOCIATE BRITISH<br />
+INSTITUTION OF NAVAL ARCHITECTS,<br />
+ETC., ETC.</p>
+
+<p class="center"><i>SECOND REVISED EDITION.</i></p>
+
+<p class="center">NEW YORK:<br />
+<span class="gesp">D. APPLETON AND COMPANY</span>,<br />
+<span class="fsize80">1, 3, <small>AND</small> 5 BOND STREET.</span><br />
+1886.</p>
+<hr class="c40" />
+
+<p><span class='pagenum'><a name="Page_ii" id="Page_ii">[ii]</a></span></p>
+<div class="fsize80">
+<h3>COPYRIGHT, 1878, 1884,</h3>
+<h2><span class="smcap">By</span> ROBERT H. THURSTON.</h2>
+</div>
+
+<hr class="c40" />
+<p class='pagenum'><a name="Page_iii" id="Page_iii">[iii]</a></p>
+
+<h2>PREFACE.</h2>
+<hr class="c05" />
+
+<p>This little work embodies the more generally interesting
+portions of lectures first written for delivery at the
+<span class="smcap">Stevens Institute of Technology</span>, in the winter of 1871-&#8217;72,
+to a mixed audience, composed, however, principally
+of engineers by profession, and of mechanics; it comprises,
+also, some material prepared for other occasions.</p>
+
+<p>These lectures have been rewritten and considerably
+extended, and have been given a form which is more appropriate
+to this method of presentation of the subject.
+The account of the gradual development of the philosophy
+of the steam-engine has been extended and considerably
+changed, both in arrangement and in method. That
+part in which the direction of improvement during the
+past history of the steam-engine, the course which it is
+to-day taking, and the direction and limitation of that
+improvement in the future, are traced, has been somewhat
+modified to accord with the character of the revised work.</p>
+
+<p>The author has consulted a large number of authors
+in the course of his work, and is very greatly indebted
+to several earlier writers. Of these, Stuart<a name="FNanchor_1_1" id="FNanchor_1_1"></a><a href="#Footnote_1_1"
+class="fnanchor">[1]</a> is entitled<span class='pagenum'><a name="Page_iv" id="Page_iv">[iv]</a></span>
+to particular mention. His &#8220;History&#8221; is the earliest
+deserving the name; and his &#8220;Anecdotes&#8221; are of exceedingly
+great interest and of equally great historical
+value. The artistic and curious little sketches at the end
+of each chapter are from John Stuart, as are, usually,
+the drawings of the older forms of engines.</p>
+
+<p>Greenwood&#8217;s excellent translation of Hero, as edited
+by Bennett Woodcroft (London, 1851), can be consulted
+by those who are curious to learn more of that interesting
+old Greek treatise.</p>
+
+<p>Some valuable matter is from Farey,<a name="FNanchor_2_2" id="FNanchor_2_2"></a><a href="#Footnote_2_2"
+class="fnanchor">[2]</a> who gives the
+most extended account extant of Newcomen&#8217;s and Watt&#8217;s
+engines. The reader who desires to know more of the
+life of Worcester, and more of the details of his work,
+will find in the very complete biography of Dircks<a name="FNanchor_3_3" id="FNanchor_3_3"></a><a href="#Footnote_3_3"
+class="fnanchor">[3]</a> all
+that he can wish to learn of that great but unfortunate
+inventor. Smiles&#8217;s admirably written biography of Watt<a name="FNanchor_4_4" id="FNanchor_4_4"></a><a href="#Footnote_4_4"
+class="fnanchor">[4]</a>
+gives an equally interesting and complete account of the
+great mechanic and of his partners; and Muirhead<a name="FNanchor_5_5" id="FNanchor_5_5"></a><a href="#Footnote_5_5"
+class="fnanchor">[5]</a> furnishes
+us with a still more detailed account of his inventions.</p>
+
+<p>For an account of the life and work of John Elder,
+the great pioneer in the introduction of the now standard<span class='pagenum'><a name="Page_v" id="Page_v">[v]</a></span>
+double-cylinder, or &#8220;compound,&#8221; engine, the student can
+consult a little biographical sketch by Prof. Rankine,
+published soon after the death of Elder.</p>
+
+<p>The only published sketch of the history of the science
+of thermo-dynamics, which plays so large a part of the philosophy
+of the steam-engine, is that of Prof. Tait&mdash;a most
+valuable monograph.</p>
+
+<p>The section of this work which treats of the causes
+and the extent of losses of heat in the steam-engine, and
+of the methods available, or possibly available, to reduce
+the amount of this now immense waste of heat, is, in some
+respects, quite new, and is equally novel in the method of
+its presentation. The portraits with which the book
+is well furnished are believed to be authentic, and, it
+is hoped, will lend interest, if not adding to the real
+value of the work.</p>
+
+<p>Among other works which have been of great assistance
+to the author, and will be found, perhaps, equally
+valuable to some of the readers of this little treatise,
+are several to which reference has not been made in
+the text. Among them the following are deserving of
+special mention: Zeuner&#8217;s &#8220;W&auml;rmetheorie,&#8221; the treatises
+of Stewart and of Maxwell, and McCulloch&#8217;s &#8220;Mechanical
+Theory of Heat,&#8221; a short but thoroughly logical
+and exact mathematical treatise; Cotterill&#8217;s &#8220;Steam-Engine
+considered as a Heat-Engine,&#8221; a more extended
+work on the same subject, which will be found an excellent
+companion to, and commentary upon, Rankine&#8217;s
+&#8220;Steam-Engine and Prime Movers,&#8221; which is the standard<span class='pagenum'><a name="Page_vi" id="Page_vi">[vi]</a></span>
+treatise on the theory of the steam-engine. The
+works of Bourne, of Holley, of Clarke, and of Forney,
+are standards on the practical every-day matters of
+steam-engine construction and management.</p>
+
+<p>The author is almost daily in receipt of inquiries
+which indicate that the above remarks will be of service
+to very many young engineers, as well as to many to
+whom the steam-engine is of interest from a more purely
+scientific point of view.</p>
+
+<hr class="l05" />
+<div class="colleft">
+<div class="footnote"><p class="left"><a name="Footnote_1_1" id="Footnote_1_1"></a><a href="#FNanchor_1_1"><span class="label">[1]</span></a>
+&#8220;History of the Steam-Engine,&#8221; London, 1824. &#8220;Anecdotes of the
+Steam-Engine,&#8221; London, 1829.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_2_2" id="Footnote_2_2"></a><a href="#FNanchor_2_2"><span class="label">[2]</span></a>
+&#8220;Treatise on the Steam-Engine,&#8221; London, 1827.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_3_3" id="Footnote_3_3"></a><a href="#FNanchor_3_3"><span class="label">[3]</span></a>
+&#8220;Life, Times, and Scientific Labors of the Second Marquis of Worcester,&#8221;
+London, 1865.</p></div>
+</div>
+
+<div class="footnote"><p class="left"><a name="Footnote_4_4" id="Footnote_4_4"></a><a href="#FNanchor_4_4"><span class="label">[4]</span></a>
+&#8220;Lives of Boulton and Watt,&#8221; London, 1865.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_5_5" id="Footnote_5_5"></a><a href="#FNanchor_5_5"><span class="label">[5]</span></a>
+&#8220;Life of James Watt,&#8221; D. Appleton &amp; Co., New York, 1859. &#8220;Mechanical
+Inventions of James Watt,&#8221; London, 1854.</p></div>
+
+<hr class="l05" />
+
+<p>&nbsp;</p>
+
+<hr class="c40" /><p class='pagenum'><a name="Page_vii" id="Page_vii">[vii]</a></p>
+<h2>CONTENTS.</h2>
+<hr class="c05" />
+
+<table width="70%" cellpadding="5" cellspacing="1" summary="ToC">
+
+<tr>
+<td>&nbsp;</td>
+<td class="center"><a href="#CHAPTER_I">CHAPTER I.</a></td>
+<td>&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="3" class="center smcap">The Steam-Engine as a Simple Machine.</td>
+</tr>
+
+<tr>
+<td class="right fsize80" colspan="3">PAGE</td>
+</tr>
+
+<tr>
+<td colspan="2" class="just smcap">Section I.&mdash;The Period of Speculation&mdash;From Hero to Worcester, b. c. 200 to
+a. d. 1650</td>
+<td class="right bot"><a href="#Page_1">1</a></td>
+</tr>
+
+<tr>
+<td>&nbsp;</td>
+<td style="text-align: justify;">Introduction&mdash;the Importance of the Steam-Engine, <a href="#Page_1">1</a>; Hero and his Treatise
+on Pneumatics, <a href="#Page_4">4</a>; Hero&#8217;s Engines, <span class="smcap">b. c.</span> 200, <a href="#Page_8">8</a>;
+William of Malmesbury on Steam, <span class="smcap">a. d.</span> 1150, <a href="#Page_10">10</a>; Hieronymus Cardan on Steam and the
+Vacuum, <a href="#Page_10">10</a>; Malthesius on the Power of Steam, <span class="smcap">a. d.</span> 1571, <a href="#Page_10">10</a>;
+Jacob Besson on the Generation of Steam, <span class="smcap">a. d.</span> 1578, <a href="#Page_11">11</a>; Ramelli&#8217;s Work on
+Machines, <span class="smcap">a. d.</span> 1588, <a href="#Page_11">11</a>; Leonardo da Vinci on the Steam-Gun, <a href="#Page_12">12</a>;
+Blasco de Garay&#8217;s Steamer, <span class="smcap">a. d.</span> 1543, <a href="#Page_12">12</a>; Battista della Porta&#8217;s
+Steam-Engine, <span class="smcap">a. d.</span> 1601, <a href="#Page_13">13</a>; Florence Rivault on the Force of Steam,
+<span class="smcap">a. d.</span> 1608, <a href="#Page_15">15</a>; Solomon de Caus&#8217;s Apparatus, <span class="smcap">a. d.</span> 1615,
+<a href="#Page_16">16</a>; Giovanni Branca&#8217;s Steam-Engine, <span class="smcap">a. d.</span> 1629, <a href="#Page_16">16</a>;
+David Ramseye&#8217;s Inventions, <span class="smcap">a. d.</span> 1630, <a href="#Page_17">17</a>; Bishop John Wilkins&#8217;s Schemes,
+<span class="smcap">a. d.</span> 1648, <a href="#Page_18">18</a>; Kircher&#8217;s Apparatus, <a href="#Page_19">19</a>.</td>
+<td>&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="3">&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="2" class="just smcap">Section II.&mdash;The Period of Application&mdash;Worcester, Papin, and Savery</td>
+<td class="bot right"><a href="#Page_19">19</a></td>
+</tr>
+
+<tr>
+<td>&nbsp;</td>
+<td class="just">Edward Somerset, Marquis of Worcester, <span class="smcap">a. d.</span> 1663, <a href="#Page_19">19</a>;
+Worcester&#8217;s Steam Pumping-Engines, <a href="#Page_21">21</a>; Jean Hautefeuille&#8217;s Alcohol and Gunpowder Engines,
+<span class="smcap">a. d.</span> 1678, <a href="#Page_24">24</a>; Huyghens&#8217;s Gunpowder-Engine, <span class="smcap">a. d.</span> 1680,
+<a href="#Page_25">25</a>; Invention in Great Britain, <a href="#Page_26">26</a>; Sir Samuel Morland, <span class="smcap">a. d.</span>
+1683, <a href="#Page_27">27</a>; Thomas Savery and his Engine, <span class="smcap">a. d.</span> 1698, <a href="#Page_31">31</a>;
+Desaguliers&#8217;s Savery Engines, <span class="smcap">a. d.</span> 1718, <a href="#Page_41">41</a>; Denys Papin and his Work,
+<span class="smcap">a. d.</span> 1675, <a href="#Page_45">45</a>; Papin&#8217;s Engines, <span class="smcap">a. d.</span> 1685-1695,
+<a href="#Page_50">50</a>; Papin&#8217;s Steam-Boilers, <a href="#Page_51">51</a>.</td>
+<td>&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="3">&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="3" class="center"><a href="#CHAPTER_II">CHAPTER II.</a></td>
+</tr>
+
+<tr>
+<td class="smcap center" colspan="3">The Steam-Engine as a Train of Mechanism.</td>
+</tr>
+
+<tr>
+<td colspan="3">&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="2" class="smcap just">The Modern Type as developed by Newcomen, Beighton, and Smeaton</td>
+<td class="right bot"><a href="#Page_55">55</a></td>
+</tr>
+
+<tr>
+<td>&nbsp;</td>
+<td class="just">Defects of the Savery Engine, <a href="#Page_55">55</a>; Thomas Newcomen, <span class="smcap">a. d.</span> 1705,
+<a href="#Page_57">57</a>; the Newcomen Steam Pumping-Engine, <a href="#Page_59">59</a>; Advantages of Newcomen&#8217;s Engine,
+<a href="#Page_60">60</a>; Potter&#8217;s and Beighton&#8217;s Improvements, <span class="smcap">a. d.</span> 1713-&#8217;18,
+<a href="#Page_61">61</a>; Smeaton&#8217;s Newcomen Engines, <span class="smcap">a. d.</span> 1775, <a href="#Page_64">64</a>; Operation
+of the Newcomen Engine, <a href="#Page_65">65</a>; Power and Economy of the Engine, <a href="#Page_69">69</a>; Introduction of the
+Newcomen Engine, <a href="#Page_70">70</a>.</td>
+<td>&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="3">&nbsp;</td>
+</tr>
+
+
+<tr>
+<td colspan="3" class="center"><a href="#CHAPTER_III">CHAPTER III.</a><span class='pagenum'><a name="Page_viii" id="Page_viii">[viii]</a></span></td>
+</tr>
+
+<tr>
+<td colspan="3" class="center smcap">The Development of the Modern Steam-Engine. James Watt and his Contemporaries.</td>
+</tr>
+
+<tr>
+<td colspan="3">&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="2" class="smcap just">Section I.&mdash;James Watt and his Inventions</td>
+<td class="right bot"><a href="#Page_79">79</a></td>
+</tr>
+
+<tr>
+<td>&nbsp;</td>
+<td class="just">James Watt, his Birth and Parentage, <a href="#Page_79">79</a>; his Standing in School, <a href="#Page_81">81</a>; he
+learns his Trade in London, <a href="#Page_81">81</a>; Return to Scotland and Settlement in Glasgow, <a href="#Page_82">82</a>; the
+Newcomen Engine Model, <a href="#Page_83">83</a>; Discovery of Latent Heat, <a href="#Page_84">84</a>; Sources of Loss in the Newcomen
+Engine, <a href="#Page_85">85</a>; Facts experimentally determined by Watt, <a href="#Page_86">86</a>; Invention of the Separate Condenser,
+<a href="#Page_87">87</a>; the Steam-Jacket and other Improvements, <a href="#Page_90">90</a>; Connection with Dr. Roebuck,
+<a href="#Page_91">91</a>; Watt meets Boulton, <a href="#Page_93">93</a>; Matthew Boulton, <a href="#Page_93">93</a>; Boulton&#8217;s
+Establishment at Soho, <a href="#Page_95">95</a>; the Partnership of Boulton and Watt, <a href="#Page_97">97</a>; the Kinneil Engine,
+<a href="#Page_97">97</a>; Watt&#8217;s Patent of 1769, <a href="#Page_98">98</a>; Work of Boulton and Watt, <a href="#Page_101">101</a>;
+the Rotative Engine, <a href="#Page_103">103</a>; the Patent of 1781, <a href="#Page_104">104</a>; the Expansion of Steam&mdash;its
+Economy, <a href="#Page_105">105</a>; the Double-Acting Engine, <a href="#Page_110">110</a>; the &#8220;Compound&#8221; Engine,
+<a href="#Page_110">110</a>; the Steam-Hammer, <a href="#Page_111">111</a>; Parallel Motions, the Counter, <a href="#Page_112">112</a>; the
+Throttle-Valve and Governor, <a href="#Page_114">114</a>; Steam, Vacuum, and Water Gauges, <a href="#Page_116">116</a>; Boulton &amp;
+Watt&#8217;s Mill-Engine, <a href="#Page_118">118</a>; the Albion Mill and its Engine, <a href="#Page_119">119</a>; the Steam-Engine
+Indicator, <a href="#Page_123">123</a>; Watt in Social Life, <a href="#Page_125">125</a>; Discovery of the Composition of Water,
+<a href="#Page_126">126</a>; Death of James Watt, <a href="#Page_128">128</a>; Memorials and Souvenirs, <a href="#Page_128">128</a>.</td>
+<td>&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="3">&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="2" class="smcap just">Section II.&mdash;The Contemporaries of James Watt</td>
+<td class="right bot"><a href="#Page_132">132</a></td>
+</tr>
+
+<tr>
+<td>&nbsp;</td>
+<td class="just">William Murdoch and his Work, <a href="#Page_132">132</a>; Invention of Gas-Lighting, <a href="#Page_134">134</a>;
+Jonathan Hornblower and the Compound Engine, <a href="#Page_135">135</a>; Causes of the Failure of Hornblower, <a href="#Page_137">137</a>;
+William Bull and Richard Trevithick, <a href="#Page_138">138</a>; Edward Cartwright and his Engine, <a href="#Page_140">140</a>.</td>
+<td>&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="3">&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="3" class="center"><a href="#CHAPTER_IV">CHAPTER IV.</a></td>
+</tr>
+
+<tr>
+<td colspan="3" class="center smcap">The Modern Steam-Engine.</td>
+</tr>
+
+<tr>
+<td colspan="3">&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="2" class="smcap just">The Second Period of Application&mdash;1800-1850&mdash;Steam-Locomotion on Railroads</td>
+<td class="right bot"><a href="#Page_144">144</a></td>
+</tr>
+
+<tr>
+<td>&nbsp;</td>
+<td class="just">Introduction, <a href="#Page_144">144</a>; the Non-Condensing Engine and the Locomotive, <a href="#Page_147">147</a>;
+Newton&#8217;s Locomotive, 1680, <a href="#Page_149">149</a>; Nathan Read&#8217;s Steam-Carriage, <a href="#Page_150">150</a>;
+Cugnot&#8217;s Steam-Carriage, 1769, <a href="#Page_151">151</a>; the Model Steam-Carriage of Watt and Murdoch, 1784, <a
+href="#Page_153">153</a>; Oliver Evans and his Plans, 1786, <a href="#Page_153">153</a>; Evans&#8217;s Oruktor Amphibolis, 1804,
+<a href="#Page_157">157</a>; Richard Trevithick&#8217;s Steam-Carriage, 1802, <a href="#Page_159">159</a>; Steam-Carriages of Griffiths
+and others, <a href="#Page_160">160</a>; Steam-Carriages of Goldsworthy Gurney, 1827, <a href="#Page_161">161</a>; Steam-Carriages of
+Walter Hancock, 1831, <a href="#Page_165">165</a>; Reports to the House of Commons, 1831, <a href="#Page_170">170</a>; the Introduction of
+the Railroad, <a href="#Page_172">172</a>; Richard Trevithick&#8217;s Locomotives, 1804, <a href="#Page_174">174</a>; John Stevens and the
+Railroad, 1812, <a href="#Page_178">178</a>; William Hedley&#8217;s Locomotives, 1812, <a href="#Page_181">181</a>; George Stephenson,
+<a href="#Page_183">183</a>; Stephenson&#8217;s Killingworth Engine, 1813, <a href="#Page_186">186</a>; Stephenson&#8217;s Second
+Locomotive, 1815, <a href="#Page_187">187</a>; Stephenson&#8217;s Safety-Lamp, 1815, <a href="#Page_187">187</a>; Robert Stephenson &amp;
+Co., 1824, <a href="#Page_190">190</a>; the Stockton &amp; Darlington Engine, 1825, <a href="#Page_191">191</a>; the Liverpool &amp;
+Manchester Railroad, 1826, <a href="#Page_193">193</a>; Trial of Competing Engines at Rainhill, 1829, <a href="#Page_195">195</a>; the
+Rocket and the Novelty, <a href="#Page_198">198</a>; Atmospheric Railways, <a href="#Page_201">201</a>; Character of George
+<span class='pagenum'><a name="Page_ix" id="Page_ix">[ix]</a></span>Stephenson, <a href="#Page_204">204</a>; the Locomotive of 1833,
+<a href="#Page_204">204</a>; Introduction of Railroads in Europe, <a href="#Page_206">206</a>; Introduction of Railroads in the United
+States, <a href="#Page_207">207</a>; John Stevens&#8217;s Experimental Railroad, 1825, <a href="#Page_207">207</a>; Horatio Allen and the
+&#8220;Stourbridge Lion,&#8221; 1829, <a href="#Page_208">208</a>; Peter Cooper&#8217;s Engine, 1829, <a href="#Page_209">209</a>; E. L.
+Miller and the S. C. Railroad, 1830, <a href="#Page_210">210</a>; the &#8220;American&#8221; Type of Engine of John B. Jervis, 1832,
+<a href="#Page_212">212</a>; Robert L. Stevens and the T-rail, 1830, <a href="#Page_214">214</a>; Matthias W. Baldwin and his Engine, 1831,
+<a href="#Page_215">215</a>; Robert Stephenson on the Growth of the Locomotive, <a href="#Page_220">220</a>.</td>
+<td>&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="3">&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="3" class="center"><a href="#CHAPTER_V">CHAPTER V.</a></td>
+</tr>
+
+<tr>
+<td colspan="3" class="center smcap">The Modern Steam-Engine.</td>
+</tr>
+
+<tr>
+<td colspan="3">&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="2" class="smcap just">The Second Period of Application&mdash;1800-1850 (continued)&mdash;The Steam-Engine applied
+to Ship-Propulsion</td>
+<td class="right bot"><a href="#Page_221">221</a></td>
+</tr>
+
+<tr>
+<td>&nbsp;</td>
+<td class="just">Introduction, <a href="#Page_221">221</a>; Ancient Prophecies, <a href="#Page_223">223</a>; the Earliest Paddle-Wheel,
+<a href="#Page_223">223</a>; Blasco de Garay&#8217;s Steam-Vessel, 1543, <a href="#Page_224">224</a>; Experiments of Dionysius Papin,
+1707, <a href="#Page_224">224</a>; Jonathan Hulls&#8217;s Steamer, 1736, <a href="#Page_225">225</a>; Bernouilli and Gauthier,
+<a href="#Page_228">228</a>; William Henry, 1782, <a href="#Page_230">230</a>; the Comte d&#8217;Auxiron, 1772, <a href="#Page_232">232</a>;
+the Marquis de Jouffroy, 1776, <a href="#Page_233">233</a>; James Rumsey, 1774, <a href="#Page_234">234</a>; John Fitch, 1785,
+<a href="#Page_235">235</a>; Fitch&#8217;s Experiments on the Delaware, 1787, <a href="#Page_237">237</a>; Fitch&#8217;s Experiments
+at New York, 1796, <a href="#Page_240">240</a>; the Prophecy of John Fitch, <a href="#Page_241">241</a>; Patrick Miller, 1786-&#8217;87,
+<a href="#Page_241">241</a>; Samuel Morey, 1793, <a href="#Page_243">243</a>; Nathan Read, 1788, <a href="#Page_244">244</a>; Dundas and
+Symmington, 1801, <a href="#Page_246">246</a>; Henry Bell and the Comet, 1811, <a href="#Page_248">248</a>; Nicholas Roosevelt, 1798,
+<a href="#Page_250">250</a>; Robert Fulton, 1802, <a href="#Page_251">251</a>; Fulton&#8217;s Torpedo-Vessels, 1801, <a
+href="#Page_252">252</a>; Fulton&#8217;s First Steamboat, 1803, <a href="#Page_253">253</a>; the Clermont, 1807, <a
+href="#Page_257">257</a>; Voyage of the Clermont to Albany, <a href="#Page_259">259</a>; Fulton&#8217;s Later Steamboats,
+<a href="#Page_260">260</a>; Fulton&#8217;s War-Steamer Fulton the First, 1815, <a href="#Page_261">261</a>; Oliver Evans, 1804,
+<a href="#Page_263">263</a>; John Stevens&#8217;s Screw-Steamer, 1804, <a href="#Page_264">264</a>; Stevens&#8217;s Steam-Boilers, 1804,
+<a href="#Page_264">264</a>; Stevens&#8217;s Iron-Clad, 1812, <a href="#Page_268">268</a>; Robert L. Stevens&#8217;s Improvements,
+<a href="#Page_270">270</a>; the &#8220;Stevens Cut-off,&#8221; 1841, <a href="#Page_276">276</a>; the Stevens Iron-Clad, 1837,
+<a href="#Page_277">277</a>; Robert L. Thurston and John Babcock, 1821, <a href="#Page_280">280</a>; James P. Allaire and the Messrs.
+Copeland, <a href="#Page_281">281</a>; Erastus W. Smith&#8217;s Compound Engine, <a href="#Page_283">283</a>; Steam-Navigation on Western
+Rivers, 1811, <a href="#Page_283">283</a>; Ocean Steam-Navigation, 1808, <a href="#Page_285">285</a>; the Savannah, 1819,
+<a href="#Page_286">286</a>; the Sirius and the Great Western, 1838, <a href="#Page_289">289</a>; the Cunard Line, 1840,
+<a href="#Page_290">290</a>; the Collins Line, 1851, <a href="#Page_291">291</a>; the Side-Lever Engine, <a href="#Page_292">292</a>;
+Introduction of Screw-Steamers, <a href="#Page_293">293</a>; John Ericsson&#8217;s Screw-Vessels, 1836, <a href="#Page_294">294</a>;
+Francis Pettit Smith, 1837, <a href="#Page_296">296</a>; the Princeton, 1841, <a href="#Page_297">297</a>; Advantages of the Screw,
+<a href="#Page_299">299</a>; the Screw on the Ocean, <a href="#Page_300">300</a>; Obstacles to Improvement, <a href="#Page_301">301</a>;
+Changes in Engine-Construction, <a href="#Page_302">302</a>; Conclusion, <a href="#Page_303">303</a>.</td>
+<td>&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="3">&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="3" class="center"><a href="#CHAPTER_VI">CHAPTER VI.</a></td>
+</tr>
+
+<tr>
+<td colspan="3" class="center smcap">The Steam-Engine of To-Day.</td>
+</tr>
+
+<tr>
+<td colspan="3">&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="2" class="just smcap">The Period of Refinement&mdash;1850 to Date</td>
+<td class="right bot"><a href="#Page_303">303</a></td>
+</tr>
+
+<tr>
+<td>&nbsp;</td>
+<td class="just">Condition of the Steam-Engine at this Time, <a href="#Page_303">303</a>; the Later Development of the Engine,
+<a href="#Page_304">304</a>; Stationary Steam-Engines, <a href="#Page_307">307</a>; the Steam-Engine for Small Powers,
+<a href="#Page_307">307</a>; the Horizontal Engine with Meyer Valve-Gear, <a href="#Page_311">311</a>; the Allen Engine,
+<a href="#Page_314">314</a>; its Performance, <a href="#Page_316">316</a>; the Detachable Valve-Gear, <a href="#Page_316">316</a>;
+the Sickels Cut-off, <a href="#Page_317">317</a>; Expansion adjusted by the Governor, <a href="#Page_318">318</a>; the Corliss Engine,
+<a href="#Page_319">319</a>;<span class='pagenum'><a name="Page_x" id="Page_x">[x]</a></span> the Greene Engine, <a
+href="#Page_321">321</a>; Perkins&#8217;s Experiments, <a href="#Page_323">323</a>; Dr. Alban&#8217;s Work, <a href="#Page_325">325</a>;
+the Perkins Compound Engine, <a href="#Page_327">327</a>; the Modern Pumping-Engine, <a href="#Page_328">328</a>; the Cornish Engine,
+<a href="#Page_328">328</a>; the Steam-Pump, <a href="#Page_331">331</a>; the Worthington Pumping-Engine, <a href="#Page_333">333</a>; the
+Compound Beam and Crank Engine, <a href="#Page_335">335</a>; the Leavitt Pumping-Engine, <a href="#Page_336">336</a>; the Stationary
+Steam-Boiler, <a href="#Page_338">338</a>; &#8220;Sectional&#8221; Steam-Boilers, <a href="#Page_343">343</a>; &#8220;Performance&#8221;
+of Boilers, <a href="#Page_344">344</a>.</td>
+<td>&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="3">&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="2" class="just smcap">Section II.&mdash;Portable and Locomotive Engines.</td>
+<td class="right bot"><a href="#Page_347">347</a></td>
+</tr>
+
+<tr>
+<td>&nbsp;</td>
+<td class="just">The Semi-Portable Engine, <a href="#Page_348">348</a>; Performance of Portable Engines, <a href="#Page_350">350</a>;
+their Efficiency, <a href="#Page_352">352</a>; the Hoadley Engine, <a href="#Page_354">354</a>; the Mills Farm and Road Engine,
+<a href="#Page_356">356</a>; Fisher&#8217;s Steam-Carriage, <a href="#Page_356">356</a>; Performance of Road-Engines, <a
+href="#Page_357">357</a>; Trial of Road-Locomotives by the Author, <a href="#Page_358">358</a>; Conclusions, <a href="#Page_358">358</a>;
+the Steam Fire-Engine, <a href="#Page_360">360</a>; the Rotary Steam-Engine and Pump, <a href="#Page_365">365</a>; the Modern Locomotive,
+<a href="#Page_368">368</a>; Dimensions and Performance, <a href="#Page_373">373</a>; Compound Engines for Locomotives,
+<a href="#Page_376">376</a>; Extent of Modern Railroads, <a href="#Page_378">378</a>;</td>
+<td>&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="3">&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="2" class="just smcap">Section III.&mdash;Marine Engines.</td>
+<td class="right bot"><a href="#Page_379">379</a></td>
+</tr>
+
+<tr>
+<td>&nbsp;</td>
+<td class="just">The Modern Marine Engine, <a href="#Page_379">379</a>; the American Beam Engine, <a href="#Page_379">379</a>; the
+Oscillating Engine and Feathering Wheel, <a href="#Page_381">381</a>; the two &#8220;Rhode Islands,&#8221; <a href="#Page_382">382</a>;
+River-Boat Engines on the Mississippi, <a href="#Page_384">384</a>; Steam Launches and Yachts, <a href="#Page_386">386</a>; Marine
+Screw-Engines, <a href="#Page_389">389</a>; the Marine Compound Engine, <a href="#Page_390">390</a>; its Introduction by John Elder and
+others, <a href="#Page_393">393</a>; Comparison with the Single-Cylinder Engine, <a href="#Page_395">395</a>; its Advantages, <a
+href="#Page_396">396</a>; the Surface Condenser, <a href="#Page_397">397</a>; Weight of Machinery, <a href="#Page_398">398</a>; Marine
+Engine Performance, <a href="#Page_398">398</a>; Relative Economy of Simple and Compound Engines, <a href="#Page_399">399</a>; the
+Screw-Propeller, <a href="#Page_399">399</a>; Chain-Propulsion, or Wire-Rope Towage, <a href="#Page_402">402</a>; Marine Steam-Boilers,
+<a href="#Page_403">403</a>; the Modern Steamship, <a href="#Page_405">405</a>; Examples of Merchant Steamers, <a href="#Page_406">406</a>;
+Naval Steamers&mdash;Classification, <a href="#Page_409">409</a>; Examples of Iron-Clad Steamers, <a href="#Page_412">412</a>; Power of the
+Marine Engine, <a href="#Page_415">415</a>; Conclusion, <a href="#Page_417">417</a>.</td>
+<td>&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="3">&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="3" class="center"><a href="#CHAPTER_VII">CHAPTER VII.</a></td>
+</tr>
+
+<tr>
+<td colspan="3" class="center smcap">The Philosophy of the Steam-Engine.</td>
+</tr>
+
+<tr>
+<td colspan="3">&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="2" class="just smcap">The History of its Growth; Energetics and Thermo-dynamics</td>
+<td class="right bot"><a href="#Page_419">419</a></td>
+</tr>
+
+<tr>
+<td>&nbsp;</td>
+<td class="just">General Outline, <a href="#Page_419">419</a>; Origin of its Power, <a href="#Page_419">419</a>; Scientific Principles
+involved in its Operation, <a href="#Page_420">420</a>; the Beginnings of Modern Science, <a href="#Page_421">421</a>; the Alexandrian
+Museum, <a href="#Page_422">422</a>; the Aristotelian Philosophy, <a href="#Page_424">424</a>; the Middle Ages, <a href="#Page_426">426</a>;
+Galileo&#8217;s Work, <a href="#Page_428">428</a>; Da Vinci and Stevinus, <a href="#Page_429">429</a>; Kepler, Hooke, and Huyghens,
+<a href="#Page_429">429</a>; Newton and the New Mechanical Philosophy, <a href="#Page_430">430</a>; the Inception of the Science of
+Energetics, <a href="#Page_433">433</a>; the Persistence of Energy, <a href="#Page_433">433</a>; Rumford&#8217;s Experiments,
+<a href="#Page_434">434</a>; Fourier, Carnot, Seguin, <a href="#Page_437">437</a>; Mayer and the Mechanical Equivalent of Heat,
+<a href="#Page_438">438</a>; Joule&#8217;s Determination of its Value, <a href="#Page_438">438</a>; Prof. Rankine&#8217;s Investigations,
+<a href="#Page_442">442</a>; Clausius-Thompson&#8217;s Principles, <a href="#Page_444">444</a>; Experimental Work of Boyle, Black, and
+Watt, <a href="#Page_446">446</a>; Robison&#8217;s, Dalton&#8217;s, Ure&#8217;s, and Biot&#8217;s Study of Pressures and Temperatures of
+Steam, <a href="#Page_447">447</a>; Arago&#8217;s and Dulong&#8217;s Researches, <a href="#Page_447">447</a>; Franklin Institute
+Investigation, <a href="#Page_447">447</a>; Cagniard de la Tour&mdash;Faraday, <a href="#Page_447">447</a>; Dr. Andrews and the Critical
+Point, <a href="#Page_448">448</a>; Donny&#8217;s and Dufour&#8217;s Researches, <a href="#Page_448">448</a>; Regnault&#8217;s
+Determination of Temperatures and Pressures of Steam, <a href="#Page_449">449</a>; Hirn&#8217;s Experiments, <a href="#Page_450">450</a>;
+R&eacute;sum&eacute; of the Philosophy of the Steam-Engine, <a href="#Page_451">451</a>; Energy&mdash;Definitions and Principles,
+<a href="#Page_451">451</a>; its Measure, <a href="#Page_452">452</a>; the Laws of Energetics, <a href="#Page_453">453</a>;
+Thermo-dynamics, <a href="#Page_453">453</a>; its Beginnings, <a href="#Page_454">454</a>; its Laws, <a href="#Page_454">454</a>;
+Rankine&#8217;s General Equation, <a href="#Page_455">455</a>; Rankine&#8217;s Treatise on the Theory of Heat-Engines,
+<a href="#Page_456">456</a>; Merits of the Great Philosopher, <a href="#Page_456">456</a>.</td>
+<td>&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="3">&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="3" class="center"><a href="#CHAPTER_VIII">CHAPTER VIII.</a><span class='pagenum'><a name="Page_xi" id="Page_xi">[xi]</a>
+</span></td>
+</tr>
+
+<tr>
+<td colspan="3" class="center smcap">The Philosophy of the Steam-Engine.</td>
+</tr>
+
+<tr>
+<td colspan="3">&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="2" class="just smcap">Its Application; its Teachings Respecting the Construction of the Engine
+and its Improvement</td>
+<td class="right bot"><a href="#Page_457">457</a></td>
+</tr>
+
+<tr>
+<td>&nbsp;</td>
+<td class="just">Origin of all Energy, <a href="#Page_457">457</a>; the Progress of Energy through Boiler and Engine,
+<a href="#Page_458">458</a>; Conditions of Heat-Development in the Boiler, <a href="#Page_458">458</a>; the Steam in the Engine,
+<a href="#Page_458">458</a>; the Expansion of Steam, <a href="#Page_459">459</a>; Conditions of Heat-Utilization, <a
+href="#Page_460">460</a>; Loss of Power in the Engine, <a href="#Page_462">462</a>; Conditions affecting the Design of the Steam-Engine,
+<a href="#Page_466">466</a>; the Problem stated, <a href="#Page_466">466</a>; Economy as affected by Pressure and Temperature,
+<a href="#Page_467">467</a>; Changes which have already occurred, <a href="#Page_468">468</a>; Direction of Changes now in Progress,
+<a href="#Page_470">470</a>; Summary of Facts, <a href="#Page_471">471</a>; Characteristics of a Good Steam-Engine,
+<a href="#Page_473">473</a>; Principles of Steam-Boiler Construction, <a href="#Page_476">476</a>.</td>
+<td>&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="3">&nbsp;</td>
+</tr>
+
+</table>
+
+<hr class="c40" /><p class='pagenum'><a name="Page_xiii" id="Page_xiii">[xiii]</a></p>
+
+<h2>LIST OF ILLUSTRATIONS.</h2>
+<hr class="c05" />
+
+<p class="ind25"><span class="smcap"><a href="#Frontispiece">Frontispiece</a></span>: The Grecian Idea of the Steam-Engine.</p>
+
+<table class="tab50" cellpadding="1" cellspacing="1" summary="List of Illustrations">
+
+<tr>
+<td class="right" style="width: 5%;"><span class="fsize80">FIG.</span></td>
+<td style="width: 87%;">&nbsp;</td>
+<td class="right" style="width: 8%;"><span class="fsize80">PAGE</span></td>
+</tr>
+
+<tr>
+<td class="top right">1.</td>
+<td class="just"><a href="#Fig1">Opening Temple-Doors by Steam, <span class="smcap">b. c.</span> 200</a></td>
+<td class="right bot">6</td>
+</tr>
+
+<tr>
+<td class="top right">2.</td>
+<td class="just"><a href="#Fig2">Steam Fountain, <span class="smcap">b. c.</span> 200</a></td>
+<td class="right bot">7</td>
+</tr>
+
+<tr>
+<td class="top right">3.</td>
+<td class="just"><a href="#Fig3">Hero&#8217;s Engine, <span class="smcap">b. c.</span> 200</a></td>
+<td class="bot right">8</td>
+</tr>
+
+<tr>
+<td class="top right">4.</td>
+<td class="just"><a href="#Fig4">Porta&#8217;s Apparatus, <span class="smcap">a. d.</span> 1601</a></td>
+<td class="bot right">14</td>
+</tr>
+
+<tr>
+<td class="top right">5.</td>
+<td class="just"><a href="#Fig5">De Caus&#8217;s Apparatus, <span class="smcap">a. d.</span> 1605</a></td>
+<td class="bot right">15</td>
+</tr>
+
+<tr>
+<td class="top right">6.</td>
+<td class="just"><a href="#Fig6">Branca&#8217;s Steam-Engine, <span class="smcap">a. d.</span> 1629</a></td>
+<td class="bot right">17</td>
+</tr>
+
+<tr>
+<td class="top right">7.</td>
+<td class="just"><a href="#Fig7">Worcester&#8217;s Steam-Fountain, <span class="smcap">a. d.</span> 1650</a></td>
+<td class="bot right">21</td>
+</tr>
+
+<tr>
+<td class="top right">8.</td>
+<td class="just"><a href="#Fig8">Worcester&#8217;s Engine, <span class="smcap">a. d.</span> 1665</a></td>
+<td class="bot right">22</td>
+</tr>
+
+<tr>
+<td class="top right">9.</td>
+<td class="just"><a href="#Fig9">Wall of Raglan Castle</a></td>
+<td class="bot right">22</td>
+</tr>
+
+<tr>
+<td class="top right">10.</td>
+<td class="just"><a href="#Fig10">Huyghens&#8217;s Engine, 1680</a></td>
+<td class="bot right">26</td>
+</tr>
+
+<tr>
+<td class="top right">11.</td>
+<td class="just"><a href="#Fig11">Savery&#8217;s Model, 1698</a></td>
+<td class="bot right">34</td>
+</tr>
+
+<tr>
+<td class="top right">12.</td>
+<td class="just"><a href="#Fig12">Savery&#8217;s Engine, 1698</a></td>
+<td class="bot right">35</td>
+</tr>
+
+<tr>
+<td class="top right">13.</td>
+<td class="just"><a href="#Fig13">Savery&#8217;s Engine, <span class="smcap">a. d.</span> 1702</a></td>
+<td class="bot right">37</td>
+</tr>
+
+<tr>
+<td class="top right">14.</td>
+<td class="just"><a href="#Fig41">Papin&#8217;s Two-Way Cock</a></td>
+<td class="bot right">42</td>
+</tr>
+
+<tr>
+<td class="top right">15.</td>
+<td class="just"><a href="#Fig15">Engine Built by Desaguliers in 1718</a></td>
+<td class="bot right">43</td>
+</tr>
+
+<tr>
+<td class="top right">16.</td>
+<td class="just"><a href="#Fig16">Papin&#8217;s Digester, 1680</a></td>
+<td class="bot right">48</td>
+</tr>
+
+<tr>
+<td class="top right">17.</td>
+<td class="just"><a href="#Fig17">Papin&#8217;s Engine</a></td>
+<td class="bot right">50</td>
+</tr>
+
+<tr>
+<td class="top right">18.</td>
+<td class="just"><a href="#Fig18">Papin&#8217;s Engine and Water-Wheel, <span class="smcap">a. d.</span> 1707</a></td>
+<td class="bot right">53</td>
+</tr>
+
+<tr>
+<td class="top right">19.</td>
+<td class="just"><a href="#Fig19">Newcomen&#8217;s Engine, <span class="smcap">a. d.</span> 1705</a></td>
+<td class="bot right">59</td>
+</tr>
+
+<tr>
+<td class="top right">20.</td>
+<td class="just"><a href="#Fig20">Beighton&#8217;s Valve-Gear, <span class="smcap">a. d.</span> 1718</a></td>
+<td class="bot right">63</td>
+</tr>
+
+<tr>
+<td class="top right">21.</td>
+<td class="just"><a href="#Fig21">Smeaton&#8217;s Newcomen Engine</a></td>
+<td class="bot right">65</td>
+</tr>
+
+<tr>
+<td class="top right">22.</td>
+<td class="just"><a href="#Fig22">Boiler of Newcomen Engine, 1763</a></td>
+<td class="bot right">67</td>
+</tr>
+
+<tr>
+<td class="top right">23.</td>
+<td class="just"><a href="#Fig23">Smeaton&#8217;s Portable-Engine Boiler, 1765</a></td>
+<td class="bot right">73</td>
+</tr>
+
+<tr>
+<td class="top right">24.</td>
+<td class="just"><a href="#Fig24">The Newcomen Model</a></td>
+<td class="bot right">84</td>
+</tr>
+
+<tr>
+<td class="top right">25.</td>
+<td class="just"><a href="#Fig25">Watt&#8217;s Experiment</a></td>
+<td class="bot right">89</td>
+</tr>
+
+<tr>
+<td class="top right">26.</td>
+<td class="just"><a href="#Fig26">Watt&#8217;s Engine, 1774</a></td>
+<td class="bot right">98</td>
+</tr>
+
+<tr>
+<td class="top right">27.</td>
+<td class="just"><a href="#Fig27">Watt&#8217;s Engine, 1781</a></td>
+<td class="bot right">104</td>
+</tr>
+
+<tr>
+<td class="top right">28.<span class='pagenum'><a name="Page_xiv" id="Page_xiv">[xiv]</a></span></td>
+<td class="just"><a href="#Fig28">Expansion of Steam</a></td>
+<td class="bot right">108</td>
+</tr>
+
+<tr>
+<td class="top right">29.</td>
+<td class="just"><a href="#Fig29">The Governor</a></td>
+<td class="bot right">115</td>
+</tr>
+
+<tr>
+<td class="top right">30.</td>
+<td class="just"><a href="#Fig30">Mercury Steam-Gauge and Glass Water-Gauge</a></td>
+<td class="bot right">117</td>
+</tr>
+
+<tr>
+<td class="top right">31.</td>
+<td class="just"><a href="#Fig31">Boulton &amp; Watt&#8217;s Double-Acting Engine, 1784</a></td>
+<td class="bot right">119</td>
+</tr>
+
+<tr>
+<td class="top right">32.</td>
+<td class="just"><a href="#Fig32">Valve-Gear of the Albion Mills Engine</a></td>
+<td class="bot right">121</td>
+</tr>
+
+<tr>
+<td class="top right">33.</td>
+<td class="just"><a href="#Fig33">Watt&#8217;s Half-Trunk Engine, 1784</a></td>
+<td class="bot right">122</td>
+</tr>
+
+<tr>
+<td class="top right">34.</td>
+<td class="just"><a href="#Fig34">The Watt Hammer, 1784</a></td>
+<td class="bot right">123</td>
+</tr>
+
+<tr>
+<td class="top right">35.</td>
+<td class="just"><a href="#Fig35">James Watt&#8217;s Workshop</a></td>
+<td class="bot right">129</td>
+</tr>
+
+<tr>
+<td class="top right">36.</td>
+<td class="just"><a href="#Fig36">Murdoch&#8217;s Oscillating Engine, 1785</a></td>
+<td class="bot right">134</td>
+</tr>
+
+<tr>
+<td class="top right">37.</td>
+<td class="just"><a href="#Fig37">Hornblower&#8217;s Compound Engine, 1781</a></td>
+<td class="bot right">136</td>
+</tr>
+
+<tr>
+<td class="top right">38.</td>
+<td class="just"><a href="#Fig38">Bull&#8217;s Pumping-Engine, 1798</a></td>
+<td class="bot right">139</td>
+</tr>
+
+<tr>
+<td class="top right">39.</td>
+<td class="just"><a href="#Fig39">Cartwright&#8217;s Engine, 1798</a></td>
+<td class="bot right">141</td>
+</tr>
+
+<tr>
+<td class="top right">40.</td>
+<td class="just"><a href="#Fig40">The First Railroad-Car, 1825</a></td>
+<td class="bot right">144</td>
+</tr>
+
+<tr>
+<td class="top right">41.</td>
+<td class="just"><a href="#Fig41">Leupold&#8217;s Engine, 1720</a></td>
+<td class="bot right">148</td>
+</tr>
+
+<tr>
+<td class="top right">42.</td>
+<td class="just"><a href="#Fig42">Newton&#8217;s Steam-Carriage, 1680</a></td>
+<td class="bot right">149</td>
+</tr>
+
+<tr>
+<td class="top right">43.</td>
+<td class="just"><a href="#Fig43">Read&#8217;s Steam-Carriage, 1790</a></td>
+<td class="bot right">150</td>
+</tr>
+
+<tr>
+<td class="top right">44.</td>
+<td class="just"><a href="#Fig44">Cugnot&#8217;s Steam-Carriage, 1770</a></td>
+<td class="bot right">151</td>
+</tr>
+
+<tr>
+<td class="top right">45.</td>
+<td class="just"><a href="#Fig45">Murdoch&#8217;s Model, 1784</a></td>
+<td class="bot right">153</td>
+</tr>
+
+<tr>
+<td class="top right">46.</td>
+<td class="just"><a href="#Fig46">Evans&#8217;s Non-Condensing Engine, 1800</a></td>
+<td class="bot right">156</td>
+</tr>
+
+<tr>
+<td class="top right">47.</td>
+<td class="just"><a href="#Fig47">Evans&#8217;s &#8220;Oruktor Amphibolis,&#8221; 1804</a></td>
+<td class="bot right">157</td>
+</tr>
+
+<tr>
+<td class="top right">48.</td>
+<td class="just"><a href="#Fig48">Gurney&#8217;s Steam-Carriage</a></td>
+<td class="bot right">163</td>
+</tr>
+
+<tr>
+<td class="top right">49.</td>
+<td class="just"><a href="#Fig49">Hancock&#8217;s &#8220;Autopsy&#8221;, 1833</a></td>
+<td class="bot right">168</td>
+</tr>
+
+<tr>
+<td class="top right">50.</td>
+<td class="just"><a href="#Fig50">Trevithick&#8217;s Locomotive, 1804</a></td>
+<td class="bot right">175</td>
+</tr>
+
+<tr>
+<td class="top right">51.</td>
+<td class="just"><a href="#Fig51">Stephenson&#8217;s Locomotive of 1815. Section</a></td>
+<td class="bot right">187</td>
+</tr>
+
+<tr>
+<td class="top right">52.</td>
+<td class="just"><a href="#Fig52">Stephenson&#8217;s No. 1 Engine, 1825</a></td>
+<td class="bot right">191</td>
+</tr>
+
+<tr>
+<td class="top right">53.</td>
+<td class="just"><a href="#Fig53">Opening of the Stockton and Darlington Railroad, 1815</a></td>
+<td class="bot right">192</td>
+</tr>
+
+<tr>
+<td class="top right">54.</td>
+<td class="just"><a href="#Fig54">The &#8220;Novelty,&#8221; 1829</a></td>
+<td class="bot right">197</td>
+</tr>
+
+<tr>
+<td class="top right">55.</td>
+<td class="just"><a href="#Fig55">The &#8220;Rocket,&#8221; 1829</a></td>
+<td class="bot right">198</td>
+</tr>
+
+<tr>
+<td class="top right">56.</td>
+<td class="just"><a href="#Fig56">The Atmospheric Railroad</a></td>
+<td class="bot right">202</td>
+</tr>
+
+<tr>
+<td class="top right">57.</td>
+<td class="just"><a href="#Fig57">Stephenson&#8217;s Locomotive, 1833</a></td>
+<td class="bot right">203</td>
+</tr>
+
+<tr>
+<td class="top right">58.</td>
+<td class="just"><a href="#Fig58">The Stephenson Valve-Gear, 1833</a></td>
+<td class="bot right">206</td>
+</tr>
+
+<tr>
+<td class="top right">59.</td>
+<td class="just"><a href="#Fig59">The &#8220;Atlantic,&#8221; 1832</a></td>
+<td class="bot right">210</td>
+</tr>
+
+<tr>
+<td class="top right">60.</td>
+<td class="just"><a href="#Fig60">The &#8220;Best Friend,&#8221; 1830</a></td>
+<td class="bot right">211</td>
+</tr>
+
+<tr>
+<td class="top right">61.</td>
+<td class="just"><a href="#Fig61">The &#8220;West Point,&#8221; 1831</a></td>
+<td class="bot right">212</td>
+</tr>
+
+<tr>
+<td class="top right">62.</td>
+<td class="just"><a href="#Fig62">The &#8220;South Carolina,&#8221; 1831</a></td>
+<td class="bot right">213</td>
+</tr>
+
+<tr>
+<td class="top right">63.</td>
+<td class="just"><a href="#Fig63">The &#8220;Stevens&#8221; Rail and Enlarged Section</a></td>
+<td class="bot right">215</td>
+</tr>
+
+<tr>
+<td class="top right">64.</td>
+<td class="just"><a href="#Fig64">&#8220;Old Ironsides,&#8221; 1832</a></td>
+<td class="bot right">216</td>
+</tr>
+
+<tr>
+<td class="top right">65.</td>
+<td class="just"><a href="#Fig65">The &#8220;E. L. Miller,&#8221; 1834</a></td>
+<td class="bot right">217</td>
+</tr>
+
+<tr>
+<td class="top right">66.</td>
+<td class="just"><a href="#Fig66">Hulls&#8217;s Steamboat, 1736</a></td>
+<td class="bot right">226</td>
+</tr>
+
+<tr>
+<td class="top right">67.</td>
+<td class="just"><a href="#Fig67">Fitch&#8217;s Model, 1785</a></td>
+<td class="bot right">236</td>
+</tr>
+
+<tr>
+<td class="top right">68.</td>
+<td class="just"><a href="#Fig68">Fitch &amp; Voight&#8217;s Boiler, 1787</a></td>
+<td class="bot right">238</td>
+</tr>
+
+<tr>
+<td class="top right">69.</td>
+<td class="just"><a href="#Fig69">Fitch&#8217;s First Boat, 1787</a></td>
+<td class="bot right">238</td>
+</tr>
+
+<tr>
+<td class="top right">70.<span class='pagenum'><a name="Page_xv" id="Page_xv">[xv]</a></span></td>
+<td class="just"><a href="#Fig70">John Fitch, 1788</a></td>
+<td class="bot right">239</td>
+</tr>
+
+<tr>
+<td class="top right">71.</td>
+<td class="just"><a href="#Fig71">John Fitch, 1796</a></td>
+<td class="bot right">240</td>
+</tr>
+
+<tr>
+<td class="top right">72.</td>
+<td class="just"><a href="#Fig72">Miller, Taylor &amp; Symmington, 1788</a></td>
+<td class="bot right">242</td>
+</tr>
+
+<tr>
+<td class="top right">73.</td>
+<td class="just"><a href="#Fig73">Read&#8217;s Boiler in Section, 1788</a></td>
+<td class="bot right">245</td>
+</tr>
+
+<tr>
+<td class="top right">74.</td>
+<td class="just"><a href="#Fig74">Read&#8217;s Multi-Tubular Boiler, 1788</a></td>
+<td class="bot right">245</td>
+</tr>
+
+<tr>
+<td class="top right">75.</td>
+<td class="just"><a href="#Fig75">The &#8220;Charlotte Dundas,&#8221; 1801</a></td>
+<td class="bot right">247</td>
+</tr>
+
+<tr>
+<td class="top right">76.</td>
+<td class="just"><a href="#Fig76">The &#8220;Comet,&#8221; 1812</a></td>
+<td class="bot right">248</td>
+</tr>
+
+<tr>
+<td class="top right">77.</td>
+<td class="just"><a href="#Fig77">Fulton&#8217;s Experiments</a></td>
+<td class="bot right">253</td>
+</tr>
+
+<tr>
+<td class="top right">78.</td>
+<td class="just"><a href="#Fig78">Fulton&#8217;s Table of Resistances</a></td>
+<td class="bot right">254</td>
+</tr>
+
+<tr>
+<td class="top right">79.</td>
+<td class="just"><a href="#Fig79">Barlow&#8217;s Water-Tube Boiler, 1793</a></td>
+<td class="bot right">256</td>
+</tr>
+
+<tr>
+<td class="top right">80.</td>
+<td class="just"><a href="#Fig80">The &#8220;Clermont,&#8221; 1807</a></td>
+<td class="bot right">258</td>
+</tr>
+
+<tr>
+<td class="top right">81.</td>
+<td class="just"><a href="#Fig81">Engine of the &#8220;Clermont,&#8221; 1808</a></td>
+<td class="bot right">258</td>
+</tr>
+
+<tr>
+<td class="top right">82.</td>
+<td class="just"><a href="#Fig82">Launch of the &#8220;Fulton the First,&#8221; 1804</a></td>
+<td class="bot right">262</td>
+</tr>
+
+<tr>
+<td class="top right">83.</td>
+<td class="just"><a href="#Fig83">Section of Steam-Boiler, 1804</a></td>
+<td class="bot right">264</td>
+</tr>
+
+<tr>
+<td class="top right">84.</td>
+<td class="just"><a href="#Fig84">Engine, Boiler, and Screw-Propellers used by Stevens, 1804</a></td>
+<td class="bot right">265</td>
+</tr>
+
+<tr>
+<td class="top right">85.</td>
+<td class="just"><a href="#Fig85">Stevens&#8217;s Screw Steamer, 1804</a></td>
+<td class="bot right">265</td>
+</tr>
+
+<tr>
+<td class="top right">86.</td>
+<td class="just"><a href="#Fig86">John Stevens&#8217;s Twin-Screw Steamer, 1805</a></td>
+<td class="bot right">269</td>
+</tr>
+
+<tr>
+<td class="top right">87.</td>
+<td class="just"><a href="#Fig87">The Feathering Paddle-Wheel</a></td>
+<td class="bot right">272</td>
+</tr>
+
+<tr>
+<td class="top right">88.</td>
+<td class="just"><a href="#Fig88">The &#8220;North America&#8221; and &#8220;Albany,&#8221; 1827-&#8217;30</a></td>
+<td class="bot right">274</td>
+</tr>
+
+<tr>
+<td class="top right">89.</td>
+<td class="just"><a href="#Fig89">Stevens&#8217;s Return Tubular Boiler, 1832</a></td>
+<td class="bot right">275</td>
+</tr>
+
+<tr>
+<td class="top right">90.</td>
+<td class="just"><a href="#Fig90">Stevens&#8217;s Valve-Motion</a></td>
+<td class="bot right">276</td>
+</tr>
+
+<tr>
+<td class="top right">91.</td>
+<td class="just"><a href="#Fig91">The &#8220;Atlantic,&#8221; 1851</a></td>
+<td class="bot right">290</td>
+</tr>
+
+<tr>
+<td class="top right">92.</td>
+<td class="just"><a href="#Fig92">The Side-Lever Engine, 1849</a></td>
+<td class="bot right">291</td>
+</tr>
+
+<tr>
+<td class="top right">93.</td>
+<td class="just"><a href="#Fig93">Vertical Stationary Steam-Engine</a></td>
+<td class="bot right">308</td>
+</tr>
+
+<tr>
+<td class="top right">94.</td>
+<td class="just"><a href="#Fig94">Vertical Stationary Steam-Engine. Section</a></td>
+<td class="bot right">309</td>
+</tr>
+
+<tr>
+<td class="top right">95.</td>
+<td class="just"><a href="#Fig95">Horizontal Stationary Steam-Engine</a></td>
+<td class="bot right">312</td>
+</tr>
+
+<tr>
+<td class="top right">96.</td>
+<td class="just"><a href="#Fig96">Horizontal Stationary Steam-Engine</a></td>
+<td class="bot right">313</td>
+</tr>
+
+<tr>
+<td class="top right">97.</td>
+<td class="just"><a href="#Fig97">Corliss Engine</a></td>
+<td class="bot right">319</td>
+</tr>
+
+<tr>
+<td class="top right">98.</td>
+<td class="just"><a href="#Fig98">Corliss Engine Valve-Motion</a></td>
+<td class="bot right">320</td>
+</tr>
+
+<tr>
+<td class="top right">99.</td>
+<td class="just"><a href="#Fig99">Greene Engine</a></td>
+<td class="bot right">321</td>
+</tr>
+
+<tr>
+<td class="top right">100.</td>
+<td class="just"><a href="#Fig100">Thurston&#8217;s Greene-Engine Valve-Gear</a></td>
+<td class="bot right">322</td>
+</tr>
+
+<tr>
+<td class="top right">101.</td>
+<td class="just"><a href="#Fig101">Cornish Pumping-Engine, 1880</a></td>
+<td class="bot right">329</td>
+</tr>
+
+<tr>
+<td class="top right">102.</td>
+<td class="just"><a href="#Fig102">Steam-Pump</a></td>
+<td class="bot right">331</td>
+</tr>
+
+<tr>
+<td class="top right">103.</td>
+<td class="just"><a href="#Fig103">The Worthington Pumping-Engine, 1876. Section</a></td>
+<td class="bot right">333</td>
+</tr>
+
+<tr>
+<td class="top right">104.</td>
+<td class="just"><a href="#Fig104">The Worthington Pumping-Engine</a></td>
+<td class="bot right">334</td>
+</tr>
+
+<tr>
+<td class="top right">105.</td>
+<td class="just"><a href="#Fig105">Double-Cylinder Pumping-Engine, 1878</a></td>
+<td class="bot right">335</td>
+</tr>
+
+<tr>
+<td class="top right">106.</td>
+<td class="just"><a href="#Fig106">The Lawrence Water-Works Engine</a></td>
+<td class="bot right">336</td>
+</tr>
+
+<tr>
+<td class="top right">107.</td>
+<td class="just"><a href="#Fig107">The Leavitt Pumping-Engine</a></td>
+<td class="bot right">337</td>
+</tr>
+
+<tr>
+<td class="top right">108.</td>
+<td class="just"><a href="#Fig108">Babcock &amp; Wilcox&#8217;s Vertical Boiler</a></td>
+<td class="bot right">341</td>
+</tr>
+
+<tr>
+<td class="top right">109.</td>
+<td class="just"><a href="#Fig109">Stationary &#8220;Locomotive&#8221; Boiler</a></td>
+<td class="bot right">342</td>
+</tr>
+
+<tr>
+<td class="top right">110.</td>
+<td class="just"><a href="#Fig110">Galloway Tube</a></td>
+<td class="bot right">343</td>
+</tr>
+
+<tr>
+<td class="top right">111.</td>
+<td class="just"><a href="#Fig111">Harrison&#8217;s Sectional Boiler</a></td>
+<td class="bot right">345</td>
+</tr>
+
+<tr>
+<td class="top right">112.<span class='pagenum'><a name="Page_xvi" id="Page_xvi">[xvi]</a></span></td>
+<td class="just"><a href="#Fig112">Babcock and Wilcox&#8217;s Sectional Boiler</a></td>
+<td class="bot right">346</td>
+</tr>
+
+<tr>
+<td class="top right">113.</td>
+<td class="just"><a href="#Fig113">Root Sectional Boiler</a></td>
+<td class="bot right">347</td>
+</tr>
+
+<tr>
+<td class="top right">114.</td>
+<td class="just"><a href="#Fig114">Semi-Portable Engine, 1878</a></td>
+<td class="bot right">348</td>
+</tr>
+
+<tr>
+<td class="top right">115.</td>
+<td class="just"><a href="#Fig115">Semi-Portable Engine, 1878</a></td>
+<td class="bot right">349</td>
+</tr>
+
+<tr>
+<td class="top right">116.</td>
+<td class="just"><a href="#Fig116">The Portable Steam-Engine, 1878</a></td>
+<td class="bot right">354</td>
+</tr>
+
+<tr>
+<td class="top right">117.</td>
+<td class="just"><a href="#Fig117">The Thrashers&#8217; Road-Engine, 1878</a></td>
+<td class="bot right">355</td>
+</tr>
+
+<tr>
+<td class="top right">118.</td>
+<td class="just"><a href="#Fig118">Fisher&#8217;s Steam-Carriage</a></td>
+<td class="bot right">356</td>
+</tr>
+
+<tr>
+<td class="top right">119.</td>
+<td class="just"><a href="#Fig119">Road and Farm Locomotive</a></td>
+<td class="bot right">357</td>
+</tr>
+
+<tr>
+<td class="top right">120.</td>
+<td class="just"><a href="#Fig120">The Latta Steam Fire-Engine</a></td>
+<td class="bot right">361</td>
+</tr>
+
+<tr>
+<td class="top right">121.</td>
+<td class="just"><a href="#Fig121">The Amoskeag Engine. Section</a></td>
+<td class="bot right">363</td>
+</tr>
+
+<tr>
+<td class="top right">122.</td>
+<td class="just"><a href="#Fig122">The Silsby Rotary Steam Fire-Engine</a></td>
+<td class="bot right">364</td>
+</tr>
+
+<tr>
+<td class="top right">123.</td>
+<td class="just"><a href="#Fig123">Rotary Steam-Engine</a></td>
+<td class="bot right">365</td>
+</tr>
+
+<tr>
+<td class="top right">124.</td>
+<td class="just"><a href="#Fig124">Rotary Pump</a></td>
+<td class="bot right">366</td>
+</tr>
+
+<tr>
+<td class="top right">125.</td>
+<td class="just"><a href="#Fig125">Tank Engine, New York Elevated Railroad</a></td>
+<td class="bot right">369</td>
+</tr>
+
+<tr>
+<td class="top right">126.</td>
+<td class="just"><a href="#Fig126">Forney&#8217;s Tank-Locomotive</a></td>
+<td class="bot right">370</td>
+</tr>
+
+<tr>
+<td class="top right">127.</td>
+<td class="just"><a href="#Fig127">British Express Engine</a></td>
+<td class="bot right">371</td>
+</tr>
+
+<tr>
+<td class="top right">128.</td>
+<td class="just"><a href="#Fig128">The Baldwin Locomotive. Section</a></td>
+<td class="bot right">372</td>
+</tr>
+
+<tr>
+<td class="top right">129.</td>
+<td class="just"><a href="#Fig129">The American Type of Express Engine, 1878</a></td>
+<td class="bot right">374</td>
+</tr>
+
+<tr>
+<td class="top right">130.</td>
+<td class="just"><a href="#Fig130">Beam Engine</a></td>
+<td class="bot right">380</td>
+</tr>
+
+<tr>
+<td class="top right">131.</td>
+<td class="just"><a href="#Fig131">Oscillating Steam-Engine and Feathering Paddle-Wheel</a></td>
+<td class="bot right">381</td>
+</tr>
+
+<tr>
+<td class="top right">132.</td>
+<td class="just"><a href="#Fig132">The Two &#8220;Rhode Islands,&#8221; 1836-1876</a></td>
+<td class="bot right">383</td>
+</tr>
+
+<tr>
+<td class="top right">133.</td>
+<td class="just"><a href="#Fig133">A Mississippi Steamboat</a></td>
+<td class="bot right">384</td>
+</tr>
+
+<tr>
+<td class="top right">134.</td>
+<td class="just"><a href="#Fig134">Steam-Launch, New York Steam-Power Company</a></td>
+<td class="bot right">386</td>
+</tr>
+
+<tr>
+<td class="top right">135.</td>
+<td class="just"><a href="#Fig135">Launch-Engine</a></td>
+<td class="bot right">387</td>
+</tr>
+
+<tr>
+<td class="top right">136.</td>
+<td class="just"><a href="#Fig136">Horizontal, Direct-acting Naval Screw Engine</a></td>
+<td class="bot right">389</td>
+</tr>
+
+<tr>
+<td class="top right">137.</td>
+<td class="just"><a href="#Fig137">Compound Marine Engine. Side Elevation</a></td>
+<td class="bot right">390</td>
+</tr>
+
+<tr>
+<td class="top right">138.</td>
+<td class="just"><a href="#Fig138">Compound Marine Engine. Front Elevation and Section</a></td>
+<td class="bot right">391</td>
+</tr>
+
+<tr>
+<td class="top right">139.</td>
+<td class="just"><a href="#Fig139">Screw-Propeller</a></td>
+<td class="bot right">400</td>
+</tr>
+
+<tr>
+<td class="top right">140.</td>
+<td class="just"><a href="#Fig140">Tug-Boat Screw</a></td>
+<td class="bot right">401</td>
+</tr>
+
+<tr>
+<td class="top right">141.</td>
+<td class="just"><a href="#Fig141">Hirsch Screw</a></td>
+<td class="bot right">401</td>
+</tr>
+
+<tr>
+<td class="top right">142.</td>
+<td class="just"><a href="#Fig142">Marine Fire-Tubular Boiler. Section</a></td>
+<td class="bot right">403</td>
+</tr>
+
+<tr>
+<td class="top right">143.</td>
+<td class="just"><a href="#Fig143">Marine High-Pressure Boiler. Section</a></td>
+<td class="bot right">404</td>
+</tr>
+
+<tr>
+<td class="top right">144.</td>
+<td class="just"><a href="#Fig144">The Modern Steamship</a></td>
+<td class="bot right">407</td>
+</tr>
+
+<tr>
+<td class="top right">145.</td>
+<td class="just"><a href="#Fig145">Modern Iron-Clads</a></td>
+<td class="bot right">410</td>
+</tr>
+
+<tr>
+<td class="top right">146.</td>
+<td class="just"><a href="#Fig146">The &#8220;Great Eastern&#8221;</a></td>
+<td class="bot right">415</td>
+</tr>
+
+<tr>
+<td class="top right">147.</td>
+<td class="just"><a href="#Fig147">The &#8220;Great Eastern&#8221; at Sea</a></td>
+<td class="bot right">416</td>
+</tr>
+
+</table>
+<hr class="c40" />
+
+<p class='pagenum'><a name="Page_xvii" id="Page_xvii">[xvii]</a></p>
+<h2>PORTRAITS.</h2>
+<hr class="c05" />
+
+<table width="50%" cellpadding="1" cellspacing="1" summary="List of Portraits">
+
+<tr>
+<td colspan="2" class="left fsize80">NO.</td>
+<td class="right fsize80">PAGE</td>
+</tr>
+
+<tr>
+<td class="top right">1.</td>
+<td class="just"><a href="#Port1">Edward Somerset, the Second Marquis of Worcester</a></td>
+<td class="bot right">20</td>
+</tr>
+
+<tr>
+<td class="top right">2.</td>
+<td class="just"><a href="#Port2">Thomas Savery</a></td>
+<td class="bot right">31</td>
+</tr>
+
+<tr>
+<td class="top right">3.</td>
+<td class="just"><a href="#Port3">Denys Papin</a></td>
+<td class="bot right">46</td>
+</tr>
+
+<tr>
+<td class="top right">4.</td>
+<td class="just"><a href="#Port4">James Watt</a></td>
+<td class="bot right">80</td>
+</tr>
+
+<tr>
+<td class="top right">5.</td>
+<td class="just"><a href="#Port5">Matthew Boulton</a></td>
+<td class="bot right">94</td>
+</tr>
+
+<tr>
+<td class="top right">6.</td>
+<td class="just"><a href="#Port6">Oliver Evans</a></td>
+<td class="bot right">154</td>
+</tr>
+
+<tr>
+<td class="top right">7.</td>
+<td class="just"><a href="#Port7">Richard Trevithick</a></td>
+<td class="bot right">174</td>
+</tr>
+
+<tr>
+<td class="top right">8.</td>
+<td class="just"><a href="#Port8">Colonel John Stevens</a></td>
+<td class="bot right">178</td>
+</tr>
+
+<tr>
+<td class="top right">9.</td>
+<td class="just"><a href="#Port9">George Stephenson</a></td>
+<td class="bot right">183</td>
+</tr>
+
+<tr>
+<td class="top right">10.</td>
+<td class="just"><a href="#Port10">Robert Fulton</a></td>
+<td class="bot right">251</td>
+</tr>
+
+<tr>
+<td class="top right">11.</td>
+<td class="just"><a href="#Port11">Robert L. Stevens</a></td>
+<td class="bot right">270</td>
+</tr>
+
+<tr>
+<td class="top right">12.</td>
+<td class="just"><a href="#Port12">John Elder</a></td>
+<td class="bot right">393</td>
+</tr>
+
+<tr>
+<td class="top right">13.</td>
+<td class="just"><a href="#Port13">Benjamin Thompson, Count Rumford</a></td>
+<td class="bot right">434</td>
+</tr>
+
+<tr>
+<td class="top right">14.</td>
+<td class="just"><a href="#Port14">James Prescott Joule</a></td>
+<td class="bot right">439</td>
+</tr>
+
+<tr>
+<td class="top right">15.</td>
+<td class="just"><a href="#Port15">Prof. W. J. M. Rankine</a></td>
+<td class="bot right">443</td>
+</tr>
+
+</table>
+
+<hr class="c40" />
+<p>&nbsp;</p>
+
+<div class="blockquot"><p>[&#8220;A Machine, receiving at distant times and from many hands new
+combinations and improvements, and becoming at last of signal benefit to
+mankind, may be compared to a rivulet swelled in its course by tributary
+streams, until it rolls along a majestic river, enriching, in its progress, provinces
+and kingdoms.</p>
+
+<p>&#8220;In retracing the current, too, from where it mingles with the ocean,
+the pretensions of even ample subsidiary streams are merged in our admiration
+of the master-flood, glorying, as it were, in its expansion. But as
+we continue to ascend, those waters which, nearer the sea, would have been
+disregarded as unimportant, begin to rival in magnitude and share our
+attention with the parent stream; until, at length, on our approaching the
+fountains of the river, it appears trickling from the rock, or oozing from
+among the flowers of the valley.</p>
+
+<p>&#8220;So, also, in developing the rise of a machine, a coarse instrument or a
+toy may be recognized as the germ of that production of mechanical genius,
+whose power and usefulness have stimulated our curiosity to mark its
+changes and to trace its origin. The same feelings of reverential gratitude
+which attached holiness to the spot whence mighty rivers sprang, also
+clothed with divinity, and raised altars in honor of, inventors of the saw,
+the plough, the potter&#8217;s wheel, and the loom.&#8221;&mdash;<span class="smcap">Stuart.</span>]</p></div>
+
+<p>&nbsp;</p>
+<hr class="c40" />
+
+<p><span class='pagenum'><a name="Page_1" id="Page_1">[1]</a></span></p>
+<h1>THE GROWTH OF THE STEAM-ENGINE.</h1>
+<hr class="c40" />
+
+<h2><a name="CHAPTER_I" id="CHAPTER_I"></a>CHAPTER I.</h2>
+
+<h3><i>THE STEAM-ENGINE AS A SIMPLE MACHINE.</i></h3>
+<hr class="c05" />
+
+<h4><span class="smcap">Section I.</span>&mdash;<span class="smcap">The Period of Speculation&mdash;from Hero
+to Worcester, b. c. 200 to a. d. 1650.</span></h4>
+
+<hr class="c05" />
+
+<p>One of the greatest of modern philosophers&mdash;the founder
+of that system of scientific philosophy which traces the
+processes of evolution in every department, whether physical
+or intellectual&mdash;has devoted a chapter of his &#8220;First
+Principles&#8221; of the new system to the consideration of the
+multiplication of the effects of the various forces, social and
+other, which are continually modifying this wonderful and
+mysterious universe of which we form a part. Herbert
+Spencer, himself an engineer, there traces the wide-spreading,
+never-ceasing influences of new inventions, of the introduction
+of new forms of mechanism, and of the growth of
+industrial organization, with a clearness and a conciseness
+which are so eminently characteristic of his style. His
+illustration of this idea by reference to the manifold effects
+of the introduction of steam-power and its latest<span class='pagenum'><a name="Page_2" id="Page_2">[2]</a></span> embodiment,
+the locomotive-engine, is one of the strongest passages
+in his work. The power of the steam-engine, and its inconceivable
+importance as an agent of civilization, has always
+been a favorite theme with philosophers and historians as
+well as poets. As Religion has always been, and still is,
+the great <i>moral</i> agent in civilizing the world, and as Science
+is the great <i>intellectual</i> promoter of civilization, so the
+Steam-Engine is, in modern times, the most important <i>physical</i>
+agent in that great work.</p>
+
+<p>It would be superfluous to attempt to enumerate the
+benefits which it has conferred upon the human race, for
+such an enumeration would include an addition to every
+comfort and the creation of almost every luxury that we
+now enjoy. The wonderful progress of the present century
+is, in a very great degree, due to the invention and improvement
+of the steam-engine, and to the ingenious application
+of its power to kinds of work that formerly taxed
+the physical energies of the human race. We cannot examine
+the methods and processes of any branch of industry
+without discovering, somewhere, the assistance and support
+of this wonderful machine. Relieving mankind from manual
+toil, it has left to the intellect the privilege of directing
+the power, formerly absorbed in physical labor, into other
+and more profitable channels. The intelligence which has
+thus conquered the powers of Nature, now finds itself free
+to do head-work; the force formerly utilized in the carrying
+of water and the hewing of wood, is now expended in
+the God-like work of <span class="smcap">thought</span>. What, then, can be more
+interesting than to trace the history of the growth of this
+wonderful machine?&mdash;the greatest among the many great
+creations of one of God&#8217;s most beneficent gifts to man&mdash;the
+power of invention.</p>
+
+<p>While following the records and traditions which relate
+to the steam-engine, I propose to call attention to the fact
+that its history illustrates the very important truth: <i>Great
+inventions are never, and great discoveries are seldom, the</i><span class='pagenum'><a name="Page_3" id="Page_3">[3]</a></span><i>
+work of any one mind</i>. Every great invention is really
+either an aggregation of minor inventions, or the final step
+of a progression. It is not a creation, but <i>a growth</i>&mdash;as
+truly so as is that of the trees in the forest. Hence, the
+same invention is frequently brought out in several countries,
+and by several individuals, simultaneously. Frequently
+an important invention is made before the world is
+ready to receive it, and the unhappy inventor is taught, by
+his failure, that it is as unfortunate to be in advance of his
+age as to be behind it. Inventions only become successful
+when they are not only needed, but when mankind is so far
+advanced in intelligence as to appreciate and to express the
+necessity for them, and to at once make use of them.</p>
+
+<p>More than half a century ago, an able New England
+writer, in a communication to an English engineering
+periodical, described the new machinery which was built
+at Newport, R. I., by John Babcock and Robert L. Thurston,
+for one of the first steamboats that ever ran between
+that city and New York. He prefaced his description with
+a frequently-quoted remark to the effect that, as Minerva
+sprang, mature in mind, in full stature of body, and completely
+armed, from the head of Jupiter, so the steam-engine
+came forth, perfect at its birth, from the brain of James
+Watt. But we shall see, as we examine the records of its
+history, that, although James Watt was <i>an</i> inventor, and
+probably the greatest of the inventors of the steam-engine,
+he was still but one of the many men who have aided in
+perfecting it, and who have now made us so familiar with
+it, and its tremendous power and its facile adaptations, that
+we have almost ceased to admire it, or to wonder at the
+workings of the still more admirable intelligence that has
+so far perfected it.</p>
+
+<p>Twenty-one centuries ago, the political power of Greece
+was broken, although Grecian civilization had risen to its
+zenith. Rome, ruder than her polished neighbor, was growing
+continually stronger, and was rapidly gaining territory by<span class='pagenum'><a name="Page_4" id="Page_4">[4]</a></span>
+absorbing weaker states. Egypt, older in civilization than
+either Greece or Rome, fell but two centuries later before
+the assault of the younger states, and became a Roman
+province. Her principal city was at this time Alexandria,
+founded by the great soldier whose name it bears, when in
+the full tide of his prosperity. It had now become a great
+and prosperous city, the centre of the commerce of the
+world, the home of students and of learned men, and its
+population was the wealthiest and most civilized of the then
+known world.</p>
+
+<p>It is among the relics of that ancient Egyptian civilization
+that we find the first records in the early history of the
+steam-engine. In Alexandria, the home of Euclid, the great
+geometrician, and possibly contemporary with that talented
+engineer and mathematician, Archimedes, a learned writer,
+called Hero, produced a manuscript which he entitled
+&#8220;Spiritalia seu Pneumatica.&#8221;</p>
+
+<p>It is quite uncertain whether Hero was the inventor of
+any number of the contrivances described in his work. It
+is most probable that the apparatus described are principally
+devices which had either been long known, or
+which were invented by Ctesibius, an inventor who was
+famous for the number and ingenuity of the hydraulic and
+pneumatic machines that he devised. Hero states, in his
+Introduction, his intention to describe existing machines
+and earlier inventions, and to add his own. Nothing in the
+text, however, indicates to whom the several machines are
+to be ascribed.<a name="FNanchor_6_6" id="FNanchor_6_6"></a><a href="#Footnote_6_6" class="fnanchor">[6]</a></p>
+
+<p>The first part of Hero&#8217;s work is devoted to applications<span class='pagenum'><a name="Page_5" id="Page_5">[5]</a></span>
+of the syphon. The 11th proposition is the first application
+of heat to produce motion of fluids.</p>
+
+<p>An altar and its pedestal are hollow and air-tight. A
+liquid is poured into the pedestal, and a pipe inserted, of
+which the lower end passes beneath the surface of the
+liquid, and the upper extremity leads through a figure standing
+at the altar, and terminates in a vessel inverted above
+this altar. When a fire is made on the altar, the heat produced
+expands the confined air, and the liquid is driven up
+the tube, issuing from the vessel in the hand of the figure
+standing by the altar, which thus seems to be offering a
+libation. This toy embodies the essential principle of all
+modern heat-engines&mdash;the change of energy from the form
+known as heat-energy into mechanical energy, or work. It
+is not at all improbable that this prototype of the modern
+wonder-working machine may have been known centuries
+before the time of Hero.</p>
+
+<p>Many forms of hydraulic apparatus, including the hand
+fire-engine, which is familiar to us, and is still used in
+many of our smaller cities, are described, the greater number
+of which are probably attributable to Ctesibius. They
+demand no description here.</p>
+
+<p>A hot-air engine, however, which is the subject of his
+37th proposition, is of real interest.</p>
+
+<div class="figcenter"><a name="Fig1" id="Fig1"></a>
+<img src="images/illo033.png" alt="Opening Temple Doors" width="350" height="376" />
+<p class="caption"><span class="smcap">Fig. 1.</span>&mdash;Opening Temple-Doors by Steam,
+<span class="smcap">b. c.</span> 200.</p></div>
+
+<p>Hero sketches and describes a method of opening temple-doors
+by the action of fire on an altar, which is an
+ingenious device, and contains all the elements of the
+machine of the Marquis of Worcester, which is generally
+considered the first real steam-engine, with the single and
+vital defect that the expanding fluid is air instead of steam.
+The <a href="#Fig1">sketch</a>, from Greenwood&#8217;s translation, exhibits the device
+very plainly. Beneath the temple-doors, in the space
+<i>A B C D</i>, is placed a spherical vessel, <i>H</i>, containing water.
+A pipe, <i>F G</i>, connects the upper part of this sphere with
+the hollow and air-tight shell of the altar above, <i>D E</i>.
+Another pipe, <i>K L M</i>, leads from the bottom of the vessel,<span class='pagenum'><a name="Page_6" id="Page_6">[6]</a></span>
+<i>H</i>, over, in syphon-shape, to the bottom of a suspended
+bucket, <i>N X</i>. The suspending cord is carried over a pulley
+and led around two vertical barrels, <i>O P</i>, turning on pivots
+at their feet, and carrying the doors above. Ropes led over
+a pulley, <i>R</i>, sustain a counterbalance, <i>W</i>.</p>
+
+<p>On building a fire on the altar, the heated air within expands,
+passes through the pipe, <i>F G</i>, and drives the water
+contained in the vessel, <i>H</i>, through the syphon, <i>K L M</i>,
+into the bucket, <i>N X</i>. The weight of the bucket, which
+then descends, turns the barrels, <i>O P</i>, raises the counterbalance,
+and opens the doors of the temple. On extinguishing
+the fire, the air is condensed, the water returns through
+the syphon from the bucket to the sphere, the counterbalance
+falls, and the doors are closed.</p>
+
+<p>Another contrivance is next described, in which the
+bucket is replaced by an air-tight bag, which, expanding as
+the heated air enters it, contracts vertically and actuates
+the mechanism, which in other respects is similar to that
+just described.</p>
+
+<p>In these devices the spherical vessel is a perfect anticipation<span class='pagenum'><a name="Page_7" id="Page_7">[7]</a></span>
+of the vessels used many centuries later by several
+so-called inventors of the steam-engine.</p>
+
+<p>Proposition 45 describes the familiar experiment of a
+ball supported aloft by a jet of fluid. In this example
+steam is generated in a close cauldron, and issues from a
+pipe inserted in the top, the ball dancing on the issuing jet.</p>
+
+<div class="figcenter"><a name="Fig2" id="Fig2"></a>
+<img src="images/illo034.png" alt="Steam Fountain" width="350" height="364" />
+<p class="caption"><span class="smcap">Fig. 2.</span>&mdash;Steam Fountain, <span class="smcap">b. c.</span> 200.</p></div>
+
+<p>No. 47 is a <a href="#Fig2">device</a> subsequently reproduced&mdash;perhaps
+reinvented by the second Marquis of Worcester.</p>
+
+<p>A strong, close vessel, <i>A B C D</i>, forms a pedestal, on
+which are mounted a spherical vessel, <i>E F</i>, and a basin.
+A pipe, <i>H K</i>, is led from the bottom of the larger vessel
+into the upper part of the sphere, and another pipe from the
+lower part of the latter, in the form of a syphon, over to
+the basin, <i>M</i>. A drain-pipe, <i>N O</i>, leads from the basin to
+the reservoir, <i>A D</i>. The whole contrivance is called &#8220;A
+fountain which is made to flow by the action of the sun&#8217;s
+rays.&#8221;</p>
+
+<p>It is operated thus: The vessel, <i>E F</i>, being filled nearly
+to the top with water, or other liquid, and exposed to the
+action of the sun&#8217;s rays, the air above the water expands,
+and drives the liquid over, through the syphon, <i>G</i>, into the
+basin, <i>M</i>, and it will fall into the pedestal, <i>A B C D</i>.</p>
+
+<p>Hero goes on to state that, on the removal of the sun&#8217;s
+rays, the air in the sphere will contract, and that the water<span class='pagenum'><a name="Page_8" id="Page_8">[8]</a></span>
+will be returned to the sphere from the pedestal. This can,
+evidently, only occur when the pipe <i>G</i> is closed previous to
+the commencement of this cooling. No such cock is mentioned,
+and it is not unlikely that the device only existed on
+paper.</p>
+
+<div class="figcenter"><a name="Fig3" id="Fig3"></a>
+<img src="images/illo035.png" alt="Hero's Engine" width="350" height="398" />
+<p class="caption"><span class="smcap">Fig. 3.</span>&mdash;Hero&#8217;s Engine, <span class="smcap">b. c.</span> 200.</p></div>
+
+<p>Several steam-boilers are described, usually simple pipes
+or cylindrical vessels, and the steam generated in them by
+the heat of the fire on the altar forms a steam-blast. This
+blast is either directed into the fire, or it &#8220;makes a blackbird
+sing,&#8221; blows a horn for a triton, or does other equally
+useless work. In one device, No. 70, the steam issues from
+a reaction-wheel revolving in the horizontal plane, and
+causes dancing images to circle about the altar. A more
+mechanical and more generally-known form of this device
+is that which is frequently described as the &#8220;First Steam
+Engine.&#8221; The <a href="#Fig3">sketch</a> from Stuart is similar in general
+form, but more elaborate in detail, than that copied by
+Greenwood, which is here also reproduced, as representing
+more accurately the simple form which the mechanism of
+the &#8220;&AElig;olipile,&#8221; or Ball of &AElig;olus, assumed in those early
+times.</p>
+
+<p>The cauldron, <i>A B</i>, contains water, and is covered by the
+steam-tight cover, <i>C D</i>. A globe is supported above the
+cauldron by a pair of tubes, terminating, the one, <i>C M</i>, in a<span class='pagenum'><a name="Page_9" id="Page_9">[9]</a></span>
+pivot, <i>L</i>, and the other, <i>E F</i>, opening directly into the
+sphere at <i>G</i>. Short, bent pipes, <i>H</i> and <i>K</i>, issue from points
+diametrically opposite each other, and are open at their
+extremities.</p>
+
+<p>A fire being made beneath the cauldron, steam is formed
+and finds exit through the pipe, <i>E F G</i>, into the globe,
+and thence rushes out of the pipes, <i>H K</i>, turning the globe
+on its axis, <i>G L</i>, by the unbalanced pressure thus produced.</p>
+
+<p>The more elaborate sketch which forms the <a href="#Frontispiece">frontispiece</a>
+represents a machine of similar character. Its design
+and ornamentation illustrate well the characteristics of
+ancient art, and the Greek idea of the steam-engine.</p>
+
+<p>This &#8220;&AElig;olipile&#8221; consisted of a globe, <i>X</i>, suspended between
+trunnions, <i>O S</i>, through one of which steam enters
+from the boiler, <i>P</i>, below. The hollow, bent arms, <i>W</i> and
+<i>Z</i>, cause the vapor to issue in such directions that the reaction
+produces a rotary movement of the globe, just as the
+rotation of reaction water-wheels is produced by the outflowing
+water.</p>
+
+<p>It is quite uncertain whether this machine was ever
+more than a toy, although it has been supposed by some
+authorities that it was actually used by the Greek priests
+for the purpose of producing motion of apparatus in their
+temples.</p>
+
+<p>It seems sufficiently remarkable that, while the power of
+steam had been, during all the many centuries that man has
+existed upon the globe, so universally displayed in so many
+of the phenomena of natural change, that mankind lived
+almost up to the Christian era without making it useful in
+giving motion even to a toy; but it excites still greater
+surprise that, from the time of Hero, we meet with no good
+evidence of its application to practical purposes for many
+hundreds of years.</p>
+
+<p>Here and there in the pages of history, and in special
+treatises, we find a hint that the knowledge of the force of
+steam was not lost; but it is not at all to the credit of<span class='pagenum'><a name="Page_10" id="Page_10">[10]</a></span> biographers
+and of historians, that they have devoted so little
+time to the task of seeking and recording information relating
+to the progress of this and other important inventions
+and improvements in the mechanic arts.</p>
+
+<p>Malmesbury states<a name="FNanchor_7_7" id="FNanchor_7_7"></a><a href="#Footnote_7_7"
+class="fnanchor">[7]</a> that, in the year <span class="smcap">a. d.</span> 1125, there
+existed at Rheims, in the church of that town, a clock designed
+or constructed by Gerbert, a professor in the schools
+there, and an organ blown by air escaping from a vessel in
+which it was compressed &#8220;by heated water.&#8221;</p>
+
+<p>Hieronymus Cardan, a wonderful mathematical genius,
+a most eccentric philosopher, and a distinguished physician,
+about the middle of the sixteenth century called attention,
+in his writings, to the power of steam, and to the facility
+with which a vacuum can be obtained by its condensation.
+This Cardan was the author of &#8220;Cardan&#8217;s
+Formula,&#8221; or rule for the solution of cubic equations, and
+was the inventor of the &#8220;smoke-jack.&#8221; He has been called
+a &#8220;philosopher, juggler, and madman.&#8221; He was certainly
+a learned mathematician, a skillful physician, and a good
+mechanic.</p>
+
+<p>Many traces are found, in the history of the sixteenth
+century, of the existence of some knowledge of the properties
+of steam, and some anticipation of the advantages
+to follow its application. Matthesius, <span class="smcap">a. d.</span> 1571, in one of
+his sermons describes a contrivance which may be termed
+a steam-engine, and enlarges on the &#8220;tremendous results
+which may follow the volcanic action of a small quantity of
+confined vapor;&#8221;<a name="FNanchor_8_8" id="FNanchor_8_8"></a><a href="#Footnote_8_8"
+class="fnanchor">[8]</a> and another writer applied the steam
+&aelig;olipile of Hero to turn the spit, and thus rivaled and excelled
+Cardan, who was introducing his &#8220;smoke-jack.&#8221;</p>
+
+<p>As Stuart says, the inventor enumerated its excellent
+qualities with great minuteness. He claimed that it would
+&#8220;eat nothing, and giving, withal, an assurance to those<span class='pagenum'><a name="Page_11" id="Page_11">[11]</a></span> partaking
+of the feast, whose suspicious natures nurse queasy
+appetites, that the haunch has not been pawed by the turnspit
+in the absence of the housewife&#8217;s eye, for the pleasure
+of licking his unclean fingers.&#8221;<a name="FNanchor_9_9" id="FNanchor_9_9"></a><a href="#Footnote_9_9" class="fnanchor">[9]</a></p>
+
+<p>Jacob Besson, a Professor of Mathematics and Natural
+Philosophy at Orleans, and who was in his time distinguished
+as a mechanician, and for his ingenuity in contriving
+illustrative models for use in his lecture-room, left evidence,
+which Beroaldus collected and published in 1578,<a name="FNanchor_10_10" id="FNanchor_10_10"></a><a
+href="#Footnote_10_10" class="fnanchor">[10]</a>
+that he had found the spirit of his time sufficiently enlightened
+to encourage him to pay great attention to applied
+mechanics and to mechanism. There was at this time a
+marked awakening of the more intelligent men of the age
+to the value of practical mechanics. A scientific tract, published
+at Orleans in 1569, and probably written by Besson,
+describes very intelligently the generation of steam by the
+communication of heat to water, and its peculiar properties.</p>
+
+<p>The French were now becoming more interested in mechanics
+and the allied sciences, and philosophers and literati,
+of native birth and imported by the court from other countries,
+were learning more of the nature and importance of
+such studies as have a bearing upon the work of the engineer
+and of the mechanic.</p>
+
+<p>Agostino Ramelli, an Italian of good family, a student
+and an artist when at leisure, a soldier and an engineer in
+busier times, was born and educated at Rome, but subsequently
+was induced to make his home in Paris. He published
+a book in 1588,<a name="FNanchor_11_11" id="FNanchor_11_11"></a><a href="#Footnote_11_11"
+class="fnanchor">[11]</a> in which he described many machines,
+adapted to various purposes, with a skill that was
+only equaled by the accuracy and general excellence of his
+delineations. This work was produced while its author was<span class='pagenum'><a name="Page_12" id="Page_12">[12]</a></span>
+residing at the French capital, supported by a pension which
+had been awarded him by Henry III. as a reward for long
+and faithful services.</p>
+
+<p>The books of Besson and of Ramelli are the first treatises
+of importance on general machinery, and were, for many
+years, at once the sources from which later writers drew
+the principal portion of their information in relation to machinery,
+and wholesome stimulants to the study of mechanism.
+These works contain descriptions of many machines
+subsequently reinvented and claimed as new by other mechanics.</p>
+
+<p>Leonardo da Vinci, well known as a mathematician, engineer,
+poet, and painter, of the sixteenth century, describes,
+it is said, a steam-gun, which he calls the &#8220;Architonnerre,&#8221;
+and ascribes to Archimedes. It was a machine composed of
+copper, and seems to have had considerable power. It threw
+a ball weighing a talent. The steam was generated by permitting
+water in a closed vessel to fall on surfaces heated
+by a charcoal fire, and by its sudden expansion to eject the
+ball.</p>
+
+<p>In the year 1825, the superintendent of the royal Spanish
+archives at Simancas furnished an account which, it was
+said, had been there discovered of an attempt, made in
+1543 by Blasco de Garay, a Spanish navy-officer under
+Charles V., to move a ship by paddle-wheels, driven, as was
+inferred from the account, by a steam-engine.</p>
+
+<p>It is impossible to say to how much credit the story is
+entitled, but, if true, it was the first attempt, so far as is now
+known, to make steam useful in developing power for practical
+purposes. Nothing is known of the form of the engine
+employed, it only having been stated that a &#8220;vessel of boiling
+water&#8221; formed a part of the apparatus.</p>
+
+<p>The account is, however, in other respects so circumstantial,
+that it has been credited by many; but it is regarded
+as apocryphal by the majority of writers upon the
+subject. It was published in 1826 by M. de Navarrete, in<span class='pagenum'><a name="Page_13" id="Page_13">[13]</a></span>
+Zach&#8217;s &#8220;Astronomical Correspondence,&#8221; in the form of a
+letter from Thomas Gonzales, Director of the Royal Archives
+at Simancas, Spain.</p>
+
+<p>In 1601, Giovanni Battista della Porta, in a work called
+&#8220;Spiritali,&#8221; described an apparatus by which the pressure
+of steam might be made to raise a column of water. It included
+the application of the condensation of steam to the
+production of a vacuum into which the water would flow.</p>
+
+<div class="figcenter"><a name="Fig4" id="Fig4"></a>
+<img src="images/illo041.png" alt="Porta's Apparatus" width="234" height="350" />
+<p class="caption"><span class="smcap">Fig. 4.</span>&mdash;Porta&#8217;s Apparatus, <span class="smcap">a. d.</span> 1601.</p></div>
+
+<p>Porta is described as a mathematician, chemist, and
+physicist, a gentleman of fortune, and an enthusiastic student
+of science. His home in Naples was a rendezvous
+for students, artists, and men of science distinguished in
+every branch. He invented the magic lantern and the
+camera obscura, and described it in his commentary on the
+&#8220;Pneumatica.&#8221; In his work,<a name="FNanchor_12_12" id="FNanchor_12_12"></a><a
+href="#Footnote_12_12" class="fnanchor">[12]</a> he described this machine
+for raising water, as shown in <a href="#Fig4">Fig. 4</a>, which differs from one
+shown by Hero in the use of steam pressure, instead of the
+pressure of heated air, for expelling the liquid.</p>
+
+<p>The retort, or boiler, is fitted to a tank from which the
+bent pipe leads into the external air. A fire being kindled
+under the retort, the steam generated rises to the upper
+part of the tank, and its pressure on the surface of the
+water drives it out through the pipe, and it is then led to
+any desired height. This was called by Porta an improved
+&#8220;Hero&#8217;s Fountain,&#8221; and was named his &#8220;Steam Fountain.&#8221;
+He described with perfect accuracy the action of condensation
+in producing a vacuum, and sketched an apparatus in
+which the vacuum thus secured was filled by water forced
+in by the pressure of the external atmosphere. His contrivances
+were not apparently ever applied to any practically
+useful purpose. We have not yet passed out of the age of
+speculation, and are just approaching the period of application.
+Porta is, nevertheless, entitled to credit as having<span class='pagenum'><a name="Page_14" id="Page_14">[14]</a></span> proposed
+an essential change in this succession, which begins
+with Hero, and which did not end with Watt.</p>
+
+<p>The use of steam in Hero&#8217;s fountain was as necessary a
+step as, although less striking than, any of the subsequent
+modifications of the machine. In Porta&#8217;s contrivance, too,
+we should note particularly the separation of the boiler from
+the &#8220;forcing vessel&#8221;&mdash;a plan often claimed as original with
+later inventors, and as constituting a fair ground for special
+distinction.</p>
+
+<p>The rude engraving (<a href="#Fig4">Fig. 4</a>) above is copied from the
+book of Porta, and shows plainly the boiler mounted above
+a furnace, from the door of which the flame is seen issuing,
+and above is the tank containing water. The opening in the
+top is closed by the plug, as shown, and the steam issuing<span class='pagenum'><a name="Page_15" id="Page_15">[15]</a></span>
+from the boiler into the tank near the top, the water is
+driven out through the pipe at the left, leading up from the
+bottom of the tank.</p>
+
+<p>Florence Rivault, a Gentleman of the Bedchamber to<span class='pagenum'><a name="Page_16" id="Page_16">[16]</a></span>
+Henry IV., and a teacher of Louis XIII., is stated by M.
+Arago, the French philosopher, to have discovered, as early
+as 1605, that water confined in a bomb-shell and there heated
+would explode the shell, however thick its walls might
+be made. The fact was published in Rivault&#8217;s treatise on
+artillery in 1608. He says: &#8220;The water is converted into
+air, and its vaporization is followed by violent explosion.&#8221;</p>
+
+<p>In 1615, Salomon de Caus, who had been an engineer
+and architect under Louis XIII. of France, and later in the
+employ of the English Prince of Wales, published a work
+at Frankfort, entitled &#8220;Les Raisons des Forces Mouvantes,
+avec diverses machines tant utile que plaisante,&#8221; in which
+he illustrated his proposition, &#8220;Water will, by the aid of
+fire, mount higher than its source,&#8221; by describing a machine
+designed to raise water by the expanding power of steam.</p>
+
+<div class="figcenter"><a name="Fig5" id="Fig5"></a>
+<img src="images/illo042.png" alt="De Caus's Apparatus" width="214" height="350" />
+<p class="caption"><span class="smcap">Fig. 5.</span>&mdash;De Caus&#8217;s Apparatus, <span class="smcap">a. d.</span> 1605.</p></div>
+
+<p>In the sketch here given (<a href="#Fig5">Fig. 5</a>), and which is copied
+from the original in &#8220;Les Raisons des Forces Mouvantes,&#8221;
+etc., <i>A</i> is the copper ball containing water; <i>B</i>, the cock at
+the extremity of the pipe, taking water from the bottom, <i>C</i>,
+of the vessel; <i>D</i>, the cock through which the vessel is filled.
+The sketch was probably made by De Caus&#8217;s own hand.</p>
+
+<p>The machine of De Caus, like that of Porta, thus consisted
+of a metal vessel partly filled with water, and in which a pipe
+was fitted, leading nearly to the bottom, and open at the
+top. Fire being applied, the steam formed by its elastic
+force drove the water out through the vertical pipe, raising
+it to a height limited only by either the desire of the
+builder or the strength of the vessel.</p>
+
+<div class="figcenter"><a name="Fig6" id="Fig6"></a>
+<img src="images/illo044.png" alt="Branca's Steam Engine" width="500" height="326" />
+<p class="caption"><span class="smcap">Fig. 6.</span>&mdash;Branca&#8217;s Steam-Engine, <span class="smcap">a. d.</span> 1629.</p></div>
+
+<p>In 1629, Giovanni Branca, of the Italian town of Loretto,
+described, in a work<a name="FNanchor_13_13" id="FNanchor_13_13"></a><a
+href="#Footnote_13_13" class="fnanchor">[13]</a> published at Rome, a number of ingenious
+mechanical contrivances, among which was a steam-engine
+(<a href="#Fig6">Fig. 6</a>), in which the steam, issuing from a boiler,
+impinged upon the vanes of a horizontal wheel. This it
+was proposed to apply to many useful purposes.</p>
+
+<p><span class='pagenum'><a name="Page_17" id="Page_17">[17]</a></span>At this time experiments were in progress in England
+which soon resulted in the useful application of steam-power
+to raising water.</p>
+
+<p>A patent, dated January 21, 1630, was granted to David
+Ramseye<a name="FNanchor_14_14" id="FNanchor_14_14"></a><a href="#Footnote_14_14" class="fnanchor">[14]</a>
+by Charles I., which covered a number of distinct
+inventions. These were: &#8220;1. To multiply and make
+saltpeter in any open field, in fower acres of ground, sufficient
+to serve all our dominions. 2. To raise water from
+low pitts by fire. 3. To make any sort of mills to goe on
+standing waters by continual motion, without help of wind,
+water, or horse. 4. To make all sortes of tapistrie without
+any weaving-loom, or waie ever yet in use in this kingdome.
+5. To make boats, shippes, and barges to goe against strong
+wind and tide. 6. To make the earth more fertile than usual.
+7. To raise water from low places and mynes, and coal
+pitts, by a new waie never yet in use. 8. To make hard
+iron soft, and likewise copper to be tuffe and soft, which is
+not in use in this kingdome. 9. To make yellow waxe white
+verie speedilie.&#8221;</p>
+
+<p>This seems to have been the first authentic reference to<span class='pagenum'><a name="Page_18" id="Page_18">[18]</a></span>
+the use of steam in the arts which has been found in English
+literature. The patentee held his grant fourteen years,
+on condition of paying an annual fee of &pound;3 6<i>s.</i> 8<i>d.</i> to the
+Crown.</p>
+
+<p>The second claim is distinct as an application of steam,
+the language being that which was then, and for a century
+and a half subsequently, always employed in speaking
+of its use. The steam-engine, in all its forms, was at that
+time known as the &#8220;fire-engine.&#8221; It would seem not
+at all improbable that the third, fifth, and seventh claims
+are also applications of steam-power.</p>
+
+<p>Thomas Grant, in 1632, and Edward Ford, in 1640, also
+patented schemes, which have not been described in detail,
+for moving ships against wind and tide by some new and
+great force.</p>
+
+<p>Dr. John Wilkins, Bishop of Chester, an eccentric but
+learned and acute scholar, described, in 1648, Cardan&#8217;s
+smoke-jack, the earlier &aelig;olipiles, and the power of the confined
+steam, and suggested, in a humorous discourse, what
+he thought to be perfectly feasible&mdash;the construction of a
+flying-machine. He says: &#8220;Might not a &#8216;high pressure&#8217;
+be applied with advantage to move wings as large as those
+of the &#8216;ruck&#8217;s&#8217; or the &#8216;chariot&#8217;? The engineer might
+probably find a corner that would do for a coal-station
+near some of the &#8216;castles&#8217;&#8221; (castles in the air). The reverend
+wit proposed the application of the smoke-jack to
+the chiming of bells, the reeling of yarn, and to rocking
+the cradle.</p>
+
+<p>Bishop Wilkins writes, in 1648 (&#8220;Mathematical Magic&#8221;),
+of &aelig;olipiles as familiar and useful pieces of apparatus, and
+describes them as consisting &#8220;of some such material as may
+endure the fire, having a small hole at which they are filled
+with water, and out of which (when the vessels are heated)
+the air doth issue forth with a strong and lasting violence.&#8221;
+&#8220;They are,&#8221; the bishop adds, &#8220;frequently used for the exciting
+and contracting of heat in the melting of glasses or<span class='pagenum'><a name="Page_19" id="Page_19">[19]</a></span>
+metals. They may also be contrived to be serviceable for
+sundry other pleasant uses, as for the moving of sails in a
+chimney-corner, the motion of which sails may be applied
+to the turning of a spit, or the like.&#8221;</p>
+
+<p>Kircher gives an engraving (&#8220;Mundus Subterraneus&#8221;)
+showing the last-named application of the &aelig;olipile; and
+Erckern (&#8220;Aula Subterranea,&#8221; 1672) gives a picture illustrating
+their application to the production of a blast in smelting
+ores. They seem to have been frequently used, and in all
+parts of Europe, during the seventeenth century, for blowing
+fires in houses, as well as in the practical work of the
+various trades, and for improving the draft of chimneys.
+The latter application is revived very frequently by the
+modern inventor.</p>
+
+<hr class="c05" />
+<h4><span class="smcap">Section II.&mdash;The Period of Application&mdash;Worcester,
+Papin, and Savery.</span></h4>
+<hr class="c05" />
+
+<p>We next meet with the first instance in which the expansive
+force of steam is supposed to have actually been
+applied to do important and useful work.</p>
+
+<p>In 1663, Edward Somerset, second Marquis of Worcester,
+published a curious collection of descriptions of his inventions,
+couched in obscure and singular language, and
+called &#8220;A Century of the Names and Scantlings of Inventions
+by me already Practised.&#8221;</p>
+
+<div class="figcenter"><a name="Fig7" id="Fig7"></a>
+<img src="images/illo048.png" alt="Worcester's Steam Fountain" width="350" height="456" />
+<p class="caption"><span class="smcap">Fig. 7.</span>&mdash;Worcester&#8217;s Steam Fountain,
+<span class="smcap">a. d.</span> 1650.</p></div>
+
+<p>One of these inventions is an apparatus for raising water
+by steam. The description was not accompanied by a
+drawing, but the sketch here given (<a href="#Fig7">Fig. 7</a>) is thought
+probably to resemble one of his earlier contrivances very
+closely.</p>
+
+<p>Steam is generated in the boiler <i>a</i>, and thence is led into
+the vessel <i>e</i>, already nearly filled with water, and fitted up
+like the apparatus of De Caus. It drives the water in a jet
+out through the pipe <i>f</i>. The vessel <i>e</i> is then shut off from
+the boiler <i>a</i>, is again filled through the pipe <i>h</i>, and the operation
+<span class='pagenum'><a name="Page_20" id="Page_20">[20]</a></span>
+is repeated. Stuart thinks it possible that the marquis
+may have even made an engine with a piston, and
+sketches it.<a name="FNanchor_15_15" id="FNanchor_15_15"></a><a href="#Footnote_15_15"
+class="fnanchor">[15]</a> The instruments of Porta and of De Caus
+were &#8220;steam fountains,&#8221; and were probably applied, if used
+at all, merely to ornamental purposes. That of the <a href="#Port1">Marquis
+of Worcester</a> was actually used for the purpose of
+elevating water for practical purposes at Vauxhall, near
+London.</p>
+
+<div class="figcenter"><a name="Port1" id="Port1"></a>
+<img src="images/illo047.png" alt="Worcester" width="350" height="427" />
+<p class="caption">Edward Somerset, the Second Marquis of Worcester.</p></div>
+
+<p>How early this invention was introduced at Raglan Castle
+by Worcester is not known, but it was probably not
+much later than 1628. In 1647 Dircks shows the marquis
+probably to have been engaged in getting out parts of the
+later engine which was erected at Vauxhall, obtaining his<span class='pagenum'><a name="Page_21" id="Page_21">[21]</a></span>
+materials from William Lambert, a brass-founder. His patent
+was issued in June, 1663.</p>
+
+<div class="figcenter"><a name="Fig8" id="Fig8"></a>
+<img src="images/illo049a.png" alt="Worcester's Engine" width="183" height="350" />
+<p class="caption"><span class="smcap">Fig. 8.</span>&mdash;Worcester&#8217;s Engine,
+<span class="smcap">a. d.</span> 1665.</p></div>
+
+<p>We nowhere find an illustrated description of the machine,
+or such an account as would enable a mechanic to
+reproduce it in all its details. Fortunately, the cells and
+grooves (<a href="#Fig9">Fig. 9</a>) remaining in the wall of the citadel of
+Raglan Castle indicate the general dimensions and arrangement
+of the engine; and Dircks, the biographer of the inventor,
+has suggested the form of apparatus shown in the
+sketch (<a href="#Fig8">Fig. 8</a>) as most perfectly in accord with the evidence
+there found, and with the written specifications.</p>
+
+<div class="figcenter"><a name="Fig9" id="Fig9"></a>
+<img src="images/illo049b.png" alt="Raglan Castle Wall" width="223" height="350" />
+<p class="caption"><span class="smcap">Fig. 9.</span>&mdash;Wall of Raglan Castle.</p></div>
+
+<p>The two vessels, <i>A A&#8242;</i>, are connected by a steam-pipe,
+<i>B B&#8242;</i>, with the boiler, <i>C</i>, behind them. <i>D</i> is the furnace.
+A vertical water-pipe, <i>E</i>, is connected with the cold-water
+vessels, <i>A A&#8242;</i>, by the pipes, <i>F F&#8242;</i>, reaching nearly to
+the bottom. Water is supplied by the pipes, <i>G G&#8242;</i>, with
+valves, <i>a a&#8242;</i>, dipping into the well or ditch, <i>H</i>. Steam from<span class='pagenum'><a name="Page_22" id="Page_22">[22]</a></span>
+the boiler being admitted to each vessel, <i>A</i> and <i>A&#8242;</i>, alternately,
+and there condensing, the vacuum formed permits
+the pressure of the atmosphere to force the water
+from the well through the pipes, <i>G</i> and <i>G&#8242;</i>. While one is
+filling, the steam is forcing the charge of water from the
+other up the discharge-pipe, <i>E</i>. As soon as each is emptied,
+the steam is shut off from it and turned into the other, and
+the condensation of the steam remaining in the vessel permits
+it to fill again. As will be seen presently, this is substantially,
+and almost precisely, the form of engine of which
+the invention is usually attributed to Savery, a later inventor.</p>
+
+<p>Worcester never succeeded in forming the great company
+which he hoped would introduce his invention on a
+scale commensurate with its importance, and his fate was
+that of nearly all inventors. He died poor and unsuccessful.</p>
+
+<p>His widow, who lived until 1681, seemed to have become
+as confident as was Worcester himself that the invention
+had value, and, long after his death, was still<span class='pagenum'><a name="Page_23" id="Page_23">[23]</a></span> endeavoring
+to secure its introduction, but with equal non-success.
+The steam-engine had taken a form which made it
+inconceivably valuable to the world, at a time when no more
+efficient means of raising water was available at the most
+valuable mines than horse-power; but the people, greatly as
+it was needed, were not yet sufficiently intelligent to avail
+themselves of the great boon, the acceptance of which was
+urged upon them with all the persistence and earnestness
+which characterizes every true inventor.</p>
+
+<p>Worcester is described by his biographer as having been
+a learned, thoughtful, studious, and good man&mdash;a Romanist
+without prejudice or bigotry, a loyal subject, free from partisan
+intolerance; as a public man, upright, honorable, and
+humane; as a scholar, learned without being pedantic; as
+a mechanic, patient, skillful, persevering, and of wonderful
+ingenuity, and of clear, almost intuitive, apprehension.</p>
+
+<p>Yet, with all these natural advantages, reinforced as they
+were by immense wealth and influence in his earlier life,
+and by hardly lessened social and political influence when
+a large fortune had been spent in experiment, and after misfortune
+had subdued his spirits and left him without money
+or a home, the inventor failed to secure the introduction of
+a device which was needed more than any other. Worcester
+had attained practical success; but the period of speculation
+was but just closing, and that of the application of
+steam had not quite yet arrived.</p>
+
+<p>The second Marquis of Worcester stands on the record
+as the first steam-engine builder, and his death marks the
+termination of the first of those periods into which we have
+divided the history of the growth of the steam-engine.</p>
+
+<p>The &#8220;water-commanding engine,&#8221; as its inventor called
+it, was the first instance in the history of the steam-engine in
+which the inventor is known to have &#8220;reduced his invention
+to practice.&#8221;</p>
+
+<p>It is evident, however, that the invention of the separate
+boiler, important as it was, had been anticipated by Porta,<span class='pagenum'><a name="Page_24" id="Page_24">[24]</a></span>
+and does not entitle the marquis to the honor, claimed for
+him by many English authorities, of being <i>the</i> inventor of
+the steam-engine. Somerset was simply <i>one</i> of those whose
+works collectively made the steam-engine.</p>
+
+<p>After the time of Worcester, we enter upon a stage of
+history which may properly be termed a period of application;
+and from this time forward steam continued to play
+a more and more important part in social economy, and its
+influence on the welfare of mankind augmented with a rapidly-increasing
+growth.</p>
+
+<p>The knowledge then existing of the immense expansive
+force of steam, and the belief that it was destined to submit
+to the control of man and to lend its immense power in
+every department of industry, were evidently not confined to
+any one nation. From Italy to Northern Germany, and
+from France to Great Britain, the distances, measured in
+time, were vastly greater then than now, when this wonderful
+genius has helped us to reduce weeks to hours;
+but there existed, notwithstanding, a very perfect system
+of communication, and the learning of every centre was
+promptly radiated to every other. It thus happened that,
+at this time, the speculative study of the steam-engine was
+confined to no part of Europe; inventors and experimenters
+were busy everywhere developing this promising scheme.</p>
+
+<p>Jean Hautefeuille, the son of a French <i>boulanger</i>, born
+at Orleans, adopted by the Duchess of Bouillon at the suggestion
+of De Sourdis, profiting by the great opportunities
+offered him, entered the Church, and became one of the
+most learned men and greatest mechanicians of his time.
+He studied the many schemes then brought forward by inventors
+with the greatest interest, and was himself prolific
+of new ideas.</p>
+
+<p>In 1678, he proposed the use of alcohol in an engine,
+&#8220;in such a manner that the liquid should evaporate and be
+condensed, <i>tour &agrave; tour</i>, without being wasted&#8221;<a name="FNanchor_16_16" id="FNanchor_16_16"></a><a
+href="#Footnote_16_16" class="fnanchor">[16]</a>&mdash;the first<span class='pagenum'><a name="Page_25" id="Page_25">[25]</a></span>
+recorded plan, probably, for surface-condensation and complete
+retention of the working-fluid. He proposed a gunpowder-engine,
+of which<a name="FNanchor_17_17" id="FNanchor_17_17"></a><a href="#Footnote_17_17" class="fnanchor">[17]</a>
+he described three varieties.</p>
+
+<p>In one of these engines he displaced the atmosphere by
+the gases produced by the explosion, and the vacuum thus
+obtained was utilized in raising water by the pressure of the
+air. In the second machine, the pressure of the gases
+evolved by the combustion of the powder acted directly
+upon the water, forcing it upward; and in the third design,
+the pressure of the vapor drove a piston, and this engine
+was described as fitted to supply power for many purposes.
+There is no evidence that he constructed these machines,
+however, and they are here referred to simply as indicating
+that all the elements of the machine were becoming well
+known, and that an ingenious mechanic, combining known
+devices, could at this time have produced the steam-engine.
+Its early appearance should evidently have been
+anticipated.</p>
+
+<p>Hautefeuille, if we may judge from evidence at hand,
+was the first to propose the use of a piston in a heat-engine,
+and his gunpowder-engine seems to have been the first machine
+which would be called a heat-engine by the modern
+mechanic. The earlier &#8220;machines&#8221; or &#8220;engines,&#8221; including
+that of Hero and those of the Marquis of Worcester, would
+rather be denominated &#8220;apparatus,&#8221; as that term is used by
+the physicist or the chemist, than a machine or an engine,
+as the terms are used by the engineer.</p>
+
+<div class="figleft"><a name="Fig10" id="Fig10"></a>
+<img src="images/illo053.png" alt="Huyghens's Engine" width="96" height="350" />
+<p class="caption"><span class="smcap">Fig. 10.</span>&mdash;<br />Huyghens&#8217;s<br />Engine,<br />1680.</p></div>
+
+<p>Huyghens, in 1680, in a memoir presented to the Academy
+of Sciences, speaks of the expansive force of gunpowder
+as capable of utilization as a convenient and portable
+mechanical power, and indicates that he had designed a
+machine in which it could be applied.</p>
+
+<p>This machine of Huyghens is of great interest, not<span class='pagenum'><a name="Page_26" id="Page_26">[26]</a></span> simply
+because it was the first gas-engine and the prototype of
+the very successful modern explosive gas-engine
+of Otto and Langen, but principally as
+having been the first engine which consisted of
+a cylinder and piston. The <a href="#Fig10">sketch</a> shows its
+form. It consisted of a cylinder, <i>A</i>, a piston,
+<i>B</i>, two relief-pipes, <i>C C</i>, fitted with check-valves
+and a system of pulleys, <i>F</i>, by which the
+weight is raised. The explosion of the powder
+at <i>H</i> expels the air from the cylinder. When
+the products of combustion have cooled, the
+pressure of the atmosphere is no longer counterbalanced
+by that of air beneath, and the piston
+is forced down, raising the weight. The plan
+was never put in practice, although the invention
+was capable of being made a working and
+possibly useful machine.</p>
+
+<p>At about this period the English attained
+some superiority over their neighbors on the
+Continent in the practical application of science
+and the development of the useful arts, and it has never since
+been lost. A sudden and great development of applied science
+and of the useful arts took place during the reign of Charles
+II., which is probably largely attributable to the interest
+taken by that monarch in many branches of construction and
+of science. He is said to have been very fond of mathematics,
+mechanics, chemistry, and natural history, and to have had
+a laboratory erected, and to have employed learned men to
+carry on experiments and lines of research for his satisfaction.
+He was especially fond of the study and investigation
+of the arts and sciences most closely related to naval
+architecture and navigation, and devoted much attention to
+the determination of the best forms of vessels, and to the
+discovery of the best kinds of ship-timber. His brother,
+the Duke of York, was equally fond of this study, and was
+his companion in some of his work.</p>
+
+<p><span class='pagenum'><a name="Page_27" id="Page_27">[27]</a></span>Great as is the influence of the monarch, to-day, in forming
+the tastes and habits and in determining the direction
+of the studies and labors of the people, his influence was
+vastly more potent in those earlier days; and it may well
+be believed that the rapid strides taken by Great Britain
+from that time were, in great degree, a consequence of the
+well-known habits of Charles II., and that the nation, which
+had an exceptional natural aptitude for mechanical pursuits,
+should have been prompted by the example of its king
+to enter upon such a course as resulted in the early attainment
+of an advanced position in all branches of applied
+science.</p>
+
+<p>The appointment, under Sir Robert Moray, the superintendent
+of the laboratory of the king, of Master Mechanic,
+was conferred upon Sir Samuel Morland, a nobleman who,
+in his practical knowledge of mechanics and in his ingenuity
+and fruitfulness of invention, was apparently almost equal
+to Worcester. He was the son of a Berkshire clergyman,
+was educated at Cambridge, where he studied mathematics
+with great interest, and entered public life soon after. He
+served the Parliament under Cromwell, and afterward went
+to Geneva. He was of a decidedly literary turn of mind,
+and wrote a history of the Piedmont churches, which gave
+him great repute with the Protestant party. He was induced
+subsequently, on the accession of Charles II., to take
+service under that monarch, whose gratitude he had earned
+by revealing a plot for his assassination.</p>
+
+<p>He received his appointment and a baronetcy in 1660, and
+immediately commenced making experiments, partly at his
+own expense and partly at the cost of the royal exchequer,
+which were usually not at all remunerative. He built hand
+fire-engines of various kinds, taking patents on them, which
+brought him as small profits as did his work for the king,
+and invented the speaking-trumpet, calculating machines,
+and a capstan. His house at Vauxhall was full of curious
+devices, the products of his own ingenuity.</p>
+
+<p><span class='pagenum'><a name="Page_28" id="Page_28">[28]</a></span>He devoted much attention to apparatus for raising
+water. His devices seem to have usually been modifications
+of the now familiar force-pump. They attracted much attention,
+and exhibitions were made of them before the king
+and queen and the court. He was sent to France on business
+relating to water-works erected for King Charles, and
+while in Paris he constructed pumps and pumping apparatus
+for the satisfaction of Louis XIV. In his book,<a name="FNanchor_18_18" id="FNanchor_18_18"></a><a
+href="#Footnote_18_18" class="fnanchor">[18]</a> published
+in Paris in 1683, and presented to the king, and an
+earlier manuscript,<a name="FNanchor_19_19" id="FNanchor_19_19"></a><a
+href="#Footnote_19_19" class="fnanchor">[19]</a> still preserved in the British Museum,
+Morland shows a perfect familiarity with the power of
+steam. He says, in the latter: &#8220;Water being evaporated
+by fire, the vapors require a greater space (about two thousand
+times) than that occupied by the water; and, rather
+than submit to imprisonment, it will burst a piece of ordnance.
+But, being controlled according to the laws of
+statics, and, by science, reduced to the measure of weight
+and balance, it bears its burden peaceably (like good horses),
+and thus may be of great use to mankind, especially for the
+raising of water, according to the following table, which
+indicates the number of pounds which may be raised six
+inches, 1,800 times an hour, by cylinders half-filled with
+water, and of the several diameters and depths of said cylinders.&#8221;</p>
+
+<p>He then gives the following table, a comparison of
+which with modern tables proves Morland to have acquired
+a very considerable and tolerably accurate knowledge of
+the volume and pressure of saturated steam:</p>
+
+<table class="fsize80" summary="P and V of Saturated Steam">
+
+<tr>
+<td class="center smcap bt br" colspan="3"><span class='pagenum'><a name="Page_29" id="Page_29">[29]</a></span>Cylinders.</td>
+<td class="center smcap bt">Pounds.</td>
+</tr>
+
+<tr>
+<td class="bt">&nbsp;</td>
+<td class="center bt br padr1 padl1">Diameter in Feet.</td>
+<td class="center bt br padr1 padl1">Depth in Feet.</td>
+<td class="center bt padr1 padl1">Weight to be Raised.</td>
+</tr>
+
+<tr>
+<td class="bt">&nbsp;</td>
+<td class="right br bt padr8">1</td>
+<td class="right br bt padr6">2</td>
+<td class="right bt padr8">15</td>
+</tr>
+
+<tr>
+<td>&nbsp;</td>
+<td class="right br padr8">2</td>
+<td class="right br padr6">4</td>
+<td class="right padr8">120</td>
+</tr>
+
+<tr>
+<td>&nbsp;</td>
+<td class="right br padr8">3</td>
+<td class="right br padr6">6</td>
+<td class="right padr8">405</td>
+</tr>
+
+<tr>
+<td>&nbsp;</td>
+<td class="right br padr8">4</td>
+<td class="right br padr6">8</td>
+<td class="right padr8">960</td>
+</tr>
+
+<tr>
+<td>&nbsp;</td>
+<td class="right br padr8">5</td>
+<td class="right br padr6">10</td>
+<td class="right padr8">1,876</td>
+</tr>
+
+<tr>
+<td class="bb">&nbsp;</td>
+<td class="right bb br padr8">6</td>
+<td class="right bb br padr6">10</td>
+<td class="right bb padr8">3,240</td>
+</tr>
+
+<tr>
+<td rowspan="18" valign="middle" class="center">Num-<br />ber<br />of<br />cylin-<br />ders<br />having<br />a<br />
+dia-<br />meter<br />of<br />6<br />feet<br />and<br />a<br />depth<br />of<br />12<br />feet.</td>
+<td class="right br padr8">1</td>
+<td class="right br padr6">12</td>
+<td class="right padr8">3,240</td>
+</tr>
+
+<tr>
+<td class="right br padr8">2</td>
+<td class="right br padr6">12</td>
+<td class="right padr8">6,480</td>
+</tr>
+
+<tr>
+<td class="right br padr8">3</td>
+<td class="right br padr6">12</td>
+<td class="right padr8">9,720</td>
+</tr>
+
+<tr>
+<td class="right br padr8">4</td>
+<td class="right br padr6">12</td>
+<td class="right padr8">12,960</td>
+</tr>
+
+<tr>
+<td class="right br padr8">5</td>
+<td class="right br padr6">12</td>
+<td class="right padr8">16,200</td>
+</tr>
+
+<tr>
+<td class="right br padr8">6</td>
+<td class="right br padr6">12</td>
+<td class="right padr8">19,440</td>
+</tr>
+
+<tr>
+<td class="right br padr8">7</td>
+<td class="right br padr6">12</td>
+<td class="right padr8">22,680</td>
+</tr>
+
+<tr>
+<td class="right br padr8">8</td>
+<td class="right br padr6">12</td>
+<td class="right padr8">25,920</td>
+</tr>
+
+<tr>
+<td class="right br padr8">9</td>
+<td class="right br padr6">12</td>
+<td class="right padr8">29,190</td>
+</tr>
+
+<tr>
+<td class="right br padr8">10</td>
+<td class="right br padr6">12</td>
+<td class="right padr8">32,400</td>
+</tr>
+
+<tr>
+<td class="right br padr8">20</td>
+<td class="right br padr6">12</td>
+<td class="right padr8">64,800</td>
+</tr>
+
+<tr>
+<td class="right br padr8">30</td>
+<td class="right br padr6">12</td>
+<td class="right padr8">97,200</td>
+</tr>
+
+<tr>
+<td class="right br padr8">40</td>
+<td class="right br padr6">12</td>
+<td class="right padr8">129,600</td>
+</tr>
+
+<tr>
+<td class="right br padr8">50</td>
+<td class="right br padr6">12</td>
+<td class="right padr8">162,000</td>
+</tr>
+
+<tr>
+<td class="right br padr8">60</td>
+<td class="right br padr6">12</td>
+<td class="right padr8">194,400</td>
+</tr>
+
+<tr>
+<td class="right br padr8">70</td>
+<td class="right br padr6">12</td>
+<td class="right padr8">226,800</td>
+</tr>
+
+<tr>
+<td class="right br padr8">80</td>
+<td class="right br padr6">12</td>
+<td class="right padr8">259,200</td>
+</tr>
+
+<tr class="bb">
+<td class="right br padr8">90</td>
+<td class="right br padr6">12</td>
+<td class="right padr8">291,600</td>
+</tr>
+
+</table>
+
+<p>&nbsp;</p>
+
+<p>The rate of enlargement of volume in the conversion of
+water into steam, as given in Morland&#8217;s book, appears remarkably
+accurate when compared with statements made
+by other early experimenters. Desaguliers gave the ratio
+of volumes at 14,000, and this was accepted as correct for
+many years, and until Watt&#8217;s experiments, which were
+quoted by Dr. Robison as giving the ratio at between
+1,800 and 1,900. Morland also states the &#8220;duty&#8221; of his
+engines in the same manner in which it is stated by engineers
+to-day.</p>
+
+<p>Morland must undoubtedly have been acquainted with
+the work of his distinguished contemporary, Lord Worcester,
+and his apparatus seems most likely to have been a
+<span class='pagenum'><a name="Page_30" id="Page_30">[30]</a></span>
+modification&mdash;perhaps improvement&mdash;of Worcester&#8217;s engine. His
+house was at Vauxhall, and the establishment set up for the
+king was in the neighborhood. It may be that Morland is
+to be credited with greater success in the introduction of
+his predecessor&#8217;s apparatus than the inventor himself.</p>
+
+<p>Dr. Hutton considered this book to have been the earliest
+account of the steam-engine, and accepts the date&mdash;1682&mdash;as
+that of the invention, and adds, that &#8220;the project
+seems to have remained obscure in both countries till 1699,
+when Savery, who probably knew more of Morland&#8217;s invention
+than he owned, obtained a patent,&#8221; etc. We have,
+however, scarcely more complete or accurate knowledge of
+the extent of Morland&#8217;s work, and of its real value, than of
+that of Worcester. Morland died in 1696, at Hammersmith,
+not far from London, and his body lies in Fulham church.</p>
+
+<p>From this time forward the minds of many mechanicians
+were earnestly at work on this problem&mdash;the raising
+of water by aid of steam. Hitherto, although many ingenious
+toys, embodying the principles of the steam-engine
+separately, and sometimes to a certain extent collectively,
+had been proposed, and even occasionally constructed, the
+world was only just ready to profit by the labors of inventors
+in this direction.</p>
+
+<p>But, at the end of the seventeenth century, English
+miners were beginning to find the greatest difficulty in
+clearing their shafts of the vast quantities of water which
+they were meeting at the considerable depths to which they
+had penetrated, and it had become a matter of vital importance
+to them to find a more powerful aid in that work
+than was then available. They were, therefore, by their
+necessities stimulated to watch for, and to be prepared
+promptly to take advantage of, such an invention when it
+should be offered them.</p>
+
+<p>The experiments of Papin, and the practical application
+of known principles by Savery, placed the needed apparatus
+in their hands.</p>
+
+<div class="figcenter"><a name="Port2" id="Port2"></a>
+<img src="images/illo058.png" alt="Savery" width="350" height="437" />
+<p class="caption">Thomas Savery.</p></div>
+
+<p><span class='pagenum'><a name="Page_31" id="Page_31">[31]</a></span>
+<span class="smcap"><a href="#Port2">Thomas Savery</a></span> was a member of a well-known family
+of Devonshire, England, and was born at Shilston, about
+1650. He was well educated, and became a military engineer.
+He exhibited great fondness for mechanics, and for
+mathematics and natural philosophy, and gave much time
+to experimenting, to the contriving of various kinds of
+apparatus, and to invention. He constructed a clock, which
+still remains in the family, and is considered an ingenious
+piece of mechanism, and is said to be of excellent workmanship.</p>
+
+<p>He invented and patented an arrangement of paddle-wheels,
+driven by a capstan<a name="FNanchor_20_20" id="FNanchor_20_20"></a><a href="#Footnote_20_20" class="fnanchor">[20]</a>
+for propelling vessels in calm
+weather, and spent some time endeavoring to secure its
+adoption by the British Admiralty and the Navy Board,<span class='pagenum'><a name="Page_32" id="Page_32">[32]</a></span>
+but met with no success. The principal objector was the
+Surveyor of the Navy, who dismissed Savery, with a remark
+which illustrates a spirit which, although not yet extinct, is
+less frequently met with in the public service now than
+then: &#8220;What have interloping people, that have no concern
+with us, to do to pretend to contrive or invent things
+for us?&#8221;<a name="FNanchor_21_21" id="FNanchor_21_21"></a><a href="#Footnote_21_21" class="fnanchor">[21]</a>
+Savery then fitted his apparatus into a small
+vessel, and exhibited its operation on the Thames. The
+invention was never introduced into the navy, however.</p>
+
+<p>It was after this time that Savery became the inventor of
+a steam-engine. It is not known whether he was familiar
+with the work of Worcester, and of earlier inventors. Desaguliers<a name="FNanchor_22_22" id="FNanchor_22_22"></a><a href="#Footnote_22_22" class="fnanchor">[22]</a>
+states that he had read the book of Worcester, and
+that he subsequently endeavored to destroy all evidence of
+the anticipation of his own invention by the marquis by buying
+up all copies of the century that he could find, and burning
+them. The story is scarcely credible. A comparison of
+the drawings given of the two engines exhibits, nevertheless,
+a striking resemblance; and, assuming that of the marquis&#8217;s
+engine to be correct, Savery is to be given credit for
+the finally successful introduction of the &#8220;semi-omnipotent&#8221;
+&#8220;water-commanding&#8221; engine of Worcester.</p>
+
+<p>The most important advance in actual construction,
+therefore, was made by Thomas Savery. The constant and
+embarrassing expense, and the engineering difficulties presented
+by the necessity of keeping the British mines, and
+particularly the deep pits of Cornwall, free from water, and
+the failure of every attempt previously made to provide
+effective and economical pumping-machinery, were noted by
+Savery, who, July 25, 1698, patented the design of the first
+engine which was ever actually employed in this work. A
+working-model was submitted to the Royal Society of<span class='pagenum'><a name="Page_33" id="Page_33">[33]</a></span> London
+in 1699, and successful experiments were made with it.
+Savery spent a considerable time in planning his engine and
+in perfecting it, and states that he expended large sums of
+money upon it.</p>
+
+<div class="figleft"><a name="Fig11" id="Fig11"></a>
+<img src="images/illo061.png" alt="Savery's Model" width="248" height="350" />
+<p class="caption"><span class="smcap">Fig. 11.</span>&mdash;Savery&#8217;s Model, 1698.</p></div>
+
+<p>Having finally succeeded in satisfying himself with its
+operation, he exhibited a model &#8220;Fire-Engine,&#8221; as it was
+called in those days, before King William III. and his court,
+at Hampton Court, in 1698, and obtained his patent without
+delay. The title of the patent reads: &#8220;A grant to
+Thomas Savery, Gentl., of the sole exercise of a new invention
+by him invented, for raising of water, and occasioning
+motion to all sorts of mill-works, by the impellant force of
+fire, which will be of great use for draining mines, serving
+towns with water, and for the working of all sorts of mills,
+when they have not the benefit of water nor constant winds;
+to hold for 14 years; with usual clauses.&#8221;</p>
+
+<p>Savery now went about the work of introducing his invention
+in a way which is in marked contrast with that
+usually adopted by the inventors of that time. He commenced
+a systematic and successful system of advertisement,
+and lost no opportunity of making his plans not
+merely known, but well understood, even in matters of detail.
+The Royal Society was then fully organized, and at one
+of its meetings he obtained permission to appear with his
+model &#8220;fire-engine&#8221; and to explain its operation; and, as
+the minutes read, &#8220;Mr. Savery entertained the Society with
+showing his engine to raise water by the force of fire. He
+was thanked for showing the experiment, which succeeded,
+according to expectation, and was approved of.&#8221; He presented
+to the Society a drawing and specifications of his
+machine, and &#8220;The Transactions&#8221;<a name="FNanchor_23_23" id="FNanchor_23_23"></a><a href="#Footnote_23_23"
+class="fnanchor">[23]</a> contain a <a href="#Fig11">copperplate
+engraving</a> and the description of his model. It consisted of
+a furnace, <i>A</i>, heating a boiler, <i>B</i>, which was connected by<span class='pagenum'><a name="Page_34" id="Page_34">[34]</a></span>
+pipes, <i>C C</i>, with two copper receivers, <i>D D</i>. There were
+led from the bottom of these receivers branch pipes, <i>F F</i>,
+which turned upward, and were united to form a rising
+main, or &#8220;forcing-pipe,&#8221; <i>G</i>.
+From the top of each receiver
+was led a pipe, which was turned
+downward, and these pipes united
+to form a suction-pipe, which
+was led down to the bottom of
+the well or reservoir from which
+the water was to be drawn. The
+maximum lift allowable was
+stated at 24 feet.</p>
+
+<p>The engine was worked as
+follows: Steam is raised in the
+boiler, <i>B</i>, and a cock, <i>C</i>, being
+opened, a receiver, <i>D</i>, is filled
+with steam. Closing the cock,
+<i>C</i>, the steam condensing in the
+receiver, a vacuum is created, and the pressure of the atmosphere
+forces the water up, through the supply-pipe,
+from the well into the receiver. Opening the cock, <i>C</i>, again,
+the check-valve in the suction-pipe at <i>E</i> closes, the steam
+drives the water out through the forcing-pipe, <i>G</i>, the clack-valve,
+<i>E</i>, on that pipe opening before it, and the liquid is
+expelled from the top of the pipe. The valve, <i>C</i>, is again
+closed; the steam again condenses, and the engine is worked
+as before. While one of the two receivers is discharging,
+the other is filling, as in the machine of the Marquis of
+Worcester, and thus the steam is drawn from the boiler
+with tolerable regularity, and the expulsion of water takes
+place with similar uniformity, the two systems of receivers
+and pipes being worked alternately by the single boiler.</p>
+
+<div class="figcenter"><a name="Fig12" id="Fig12"></a>
+<img src="images/illo062.png" alt="Savery's Engine" width="350" height="328" />
+<p class="caption"><span class="smcap">Fig. 12.</span>&mdash;Savery&#8217;s Engine, 1698.</p></div>
+
+<p>In another and still simpler little machine,<a name="FNanchor_24_24" id="FNanchor_24_24"></a><a href="#Footnote_24_24"
+class="fnanchor">[24]</a> which he<span class='pagenum'><a name="Page_35" id="Page_35">[35]</a></span>
+erected at Kensington (<a href="#Fig12">Fig. 12</a>), the same general plan
+was adopted, combining a suction-pipe, <i>A</i>, 16 feet long
+and 3 inches in diameter; a single receiver, <i>B</i>, capable
+of containing 13 gallons; a boiler, <i>C</i>, of about 40 gallons
+capacity; a forcing-pipe, <i>D</i>, 42 feet high, with the connecting
+pipe and cocks, <i>E F G</i>; and the method of
+operation was as already described, except that <i>surface-condensation</i>
+was employed, the cock, <i>F</i>, being arranged
+to shower water from the rising main over the receiver,
+as shown. Of the first engine Switzer says: &#8220;I have
+heard him say myself, that the very first time he played,
+it was in a potter&#8217;s house at Lambeth, where, though it was
+a small engine, yet it (the water) forced its way through
+the roof, and struck off the tiles in a manner that surprised
+all the spectators.&#8221;</p>
+
+<p>The Kensington engine cost &pound;50, and raised 3,000 gallons
+per hour, filling the receiver four times a minute, and
+required a bushel of coal per day. Switzer remarks: &#8220;It
+must be noted that this engine is but a small one in comparison
+with many others that are made for coal-works;
+but this is sufficient for any reasonable family, and other<span class='pagenum'><a name="Page_36" id="Page_36">[36]</a></span>
+uses required of it in watering all middling gardens.&#8221; He
+cautions the operator: &#8220;When you have raised water
+enough, and you design to leave off working the engine,
+take away all the fire from under the boiler, and open the
+cock (connected to the funnel) to let out the steam, which
+would otherwise, were it to remain confined, perhaps burst
+the engine.&#8221;</p>
+
+<p>With the intention of making his invention more generally
+known, and hoping to introduce it as a pumping-engine
+in the mining districts of Cornwall, Savery wrote a prospectus
+for general circulation, which contains the earliest
+account of the later and more effective form of engine. He
+entitled his pamphlet &#8220;The Miner&#8217;s Friend; or, A Description
+of an Engine to raise Water by Fire described, and the
+Manner of fixing it in Mines, with an Account of the several
+Uses it is applicable to, and an Answer to the Objections
+against it.&#8221; It was printed in London in 1702, for
+S. Crouch, and was distributed among the proprietors and
+managers of mines, who were then finding the flow of water
+at depths so great as, in some cases, to bar further progress.
+In many cases, the cost of drainage left no satisfactory margin
+of profit. In one mine, 500 horses were employed raising
+water, by the then usual method of using horse-gins
+and buckets.</p>
+
+<p>The approval of the King and of the Royal Society, and
+the countenance of the mine-adventurers of England, were
+acknowledged by the author, who addressed his pamphlet to
+them.</p>
+
+<p>The engraving of the engine was reproduced, with the
+description, in Harris&#8217;s &#8220;Lexicon Technicum,&#8221; 1704; in
+Switzer&#8217;s &#8220;Hydrostatics,&#8221; 1729; and in Desaguliers&#8217;s &#8220;Experimental
+Philosophy,&#8221; 1744.</p>
+
+<p>The sketch which here follows is a neater engraving of
+the same machine. Savery&#8217;s engine is shown in <a href="#Fig13">Fig. 13</a>,
+as described by Savery himself, in 1702, in &#8220;The Miner&#8217;s
+Friend.&#8221;</p>
+
+<div class="figcenter"><a name="Fig13" id="Fig13"></a>
+<img src="images/illo064.png" alt="Savery's Engine" width="350" height="493" />
+<p class="caption"><span class="smcap">Fig. 13.</span>&mdash;Savery&#8217;s Engine, <span class="smcap">a. d.</span> 1702.</p></div>
+
+<p><span class='pagenum'><a name="Page_37" id="Page_37">[37]</a></span><i>L</i> is the boiler in which steam is raised, and through
+the pipes <i>O O</i> it is alternately let into the vessels <i>P P</i>.</p>
+
+<p>Suppose it to pass into the left-hand vessel first. The
+valve <i>M</i> being closed, and <i>R</i> being opened, the water contained
+in <i>P</i> is driven out and up the pipe <i>S</i> to the desired
+height, where it is discharged.</p>
+
+<p>The valve <i>R</i> is then closed, and the valve in the pipe <i>O</i>;
+the valve <i>M</i> is next opened, and condensing water is turned
+upon the exterior of <i>P</i> by the cock <i>Y</i>, leading water from
+the cistern <i>X</i>. As the steam contained in <i>P</i> is condensed,
+forming a vacuum there, a fresh charge of water is driven
+by atmospheric pressure up the pipe <i>T</i>.</p>
+
+<p>Meantime, steam from the boiler has been let into the
+right-hand vessel <i>P</i>, the cock <i>W</i> having been first closed,
+and <i>R</i> opened.</p>
+
+<p><span class='pagenum'><a name="Page_38" id="Page_38">[38]</a></span>The charge of water is driven out through the lower
+pipe and the cock <i>R</i>, and up the pipe <i>S</i> as before, while the
+other vessel is refilling preparatory to acting in its turn.</p>
+
+<p>The two vessels are thus alternately charged and discharged,
+as long as is necessary.</p>
+
+<p>Savery&#8217;s method of supplying his boiler with water was
+at once simple and ingenious.</p>
+
+<p>The small boiler, <i>D</i>, is filled with water from any convenient
+source, as from the stand-pipe, <i>S</i>. A fire is then
+built under it, and, when the pressure of steam in <i>D</i> becomes
+greater than in the main boiler, <i>L</i>, a communication
+is opened between their lower ends, and the water passes,
+under pressure, from the smaller to the larger boiler, which
+is thus &#8220;fed&#8221; without interrupting the work. <i>G</i> and <i>N</i>
+are <i>gauge-cocks</i>, by which the height of water in the boilers
+is determined; they were first adopted by Savery.</p>
+
+<p>Here we find, therefore, the first really practicable and
+commercially valuable steam-engine. Thomas Savery is
+entitled to the credit of having been the first to introduce a
+machine in which the power of heat, acting through the
+medium of steam, was rendered generally useful.</p>
+
+<p>It will be noticed that Savery, like the Marquis of
+Worcester, used a boiler separate from the water-reservoir.</p>
+
+<p>He added to the &#8220;water-commanding engine&#8221; of the
+marquis the system of <i>surface-condensation</i>, by which he
+was enabled to charge his vessels when it became necessary
+to refill them; and added, also, the secondary boiler, which
+enabled him to supply the working-boiler with water without
+interrupting its work.</p>
+
+<p>The machine was thus made capable of working uninterruptedly
+for a period of time only limited by its own decay.</p>
+
+<p>Savery never fitted his boilers with safety-valves, although
+it was done earlier by Papin; and in deep mines
+he was compelled to make use of higher pressures than his
+rudely-constructed boilers could safely bear.</p>
+
+<p>Savery&#8217;s engine was used at a number of mines, and<span class='pagenum'><a name="Page_39" id="Page_39">[39]</a></span>
+also for supplying water to towns; some large estates,
+country houses, and other private establishments, employed
+them for the same purpose. They did not, however, come
+into general use among the mines, because, according to
+Desaguliers, they were apprehensive of danger from the
+explosion of the boilers or receivers. As Desaguliers wrote
+subsequently: &#8220;Savery made a great many experiments
+to bring this machine to perfection, and did erect several
+which raised water very well for gentlemen&#8217;s seats, but
+could not succeed for mines, or supplying towns, where the
+water was to be raised very high and in great quantities;
+for then the steam required being boiled up to such a
+strength as to be ready to tear all the vessels to pieces.&#8221;
+&#8220;I have known Captain Savery, at York&#8217;s buildings, to
+make steam eight or ten times stronger than common air;
+and then its heat was so great that it would melt common
+soft solder, and its strength so great as to blow open several
+joints of the machine; so that he was forced to be at the
+pains and charge to have all his joints soldered with spelter
+or hard solder.&#8221;</p>
+
+<p>Although there were other difficulties in the application
+of the Savery engine to many kinds of work, this was the
+most serious one, and explosions did occur with fatal results.
+The writer just quoted relates, in his &#8220;Experimental
+Philosophy,&#8221; that a man who was ignorant of the nature
+of the engine undertook to work a machine which Desaguliers
+had provided with a safety-valve to avoid this very
+danger, &#8220;and, having hung the weight at the further end of
+the steelyard, in order to collect more steam in order to
+make his work the quicker, he hung also a very heavy
+plumber&#8217;s iron upon the end of the steelyard; the consequence
+proved fatal; for, after some time, the steam, not
+being able, with the safety-cock, to raise up the steelyard
+loaded with all this unusual weight, burst the boiler with a
+great explosion, and killed the poor man.&#8221; This is probably
+the earliest record of a steam-boiler explosion.</p>
+
+<p><span class='pagenum'><a name="Page_40" id="Page_40">[40]</a></span>Savery proposed to use his engine for driving mills; but
+there is no evidence that he actually made such an application
+of the machine, although it was afterward so applied by
+others. The engine was not well adapted to the drainage of
+surface-land, as the elevation of large quantities of water
+through small heights required great capacity of receivers,
+or compelled the use of several engines for each case. The
+filling of the receivers, in such cases, also compelled the
+heating of large areas of cold and wet metallic surfaces by
+the steam at each operation, and thus made the work comparatively
+wasteful of fuel. Where used in mines, they
+were necessarily placed within 30 feet or less of the lowest
+level, and were therefore exposed to danger of submergence
+whenever, by any accident, the water should rise above
+that level. In many cases this would result in the loss of
+the engine, and the mine would remain &#8220;drowned,&#8221; unless
+another engine should be procured to pump it out. Where
+the mine was deep, the water was forced by the pressure
+of steam from the level of the engine-station to the top of
+the lift. This compelled the use of pressures of several
+atmospheres in many cases; and a pressure of three atmospheres,
+or about 45 pounds per square inch, was considered,
+in those days, as about the maximum pressure allowable.
+This difficulty was met by setting a separate engine
+at every 60 or 80 feet, and pumping the water from one to
+the other. If any one engine in the set became disabled,
+the pumping was interrupted until that one machine could
+be repaired. The size of Savery&#8217;s largest boilers was not
+great, their maximum diameter not exceeding two and a
+half feet. This made it necessary to provide several of his
+engines, usually, for a single mine, and at each level. The
+first cost and the expense of repairs were exceedingly serious
+items. The expense and danger, either real or apparent,
+were thus sufficient to deter many from their use, and
+the old method of raising water by horse-power was adhered
+to.</p>
+
+<p><span class='pagenum'><a name="Page_41" id="Page_41">[41]</a></span>The consumption of fuel with these engines was very
+great. The steam was not generated economically, as the
+boilers used were of such simple forms as only could then
+be produced, and presented too little heating surface to secure
+a very complete transfer of heat from the gases of
+combustion to the water within the boiler. This waste in
+the generation of steam in these uneconomical boilers was
+followed by still more serious waste in its application, without
+expansion, to the expulsion of water from a metallic
+receiver, the cold and wet sides of which absorbed heat
+with the greatest avidity. The great mass of the liquid was
+not, however, heated by the steam, and was expelled at the
+temperature at which it was raised from below.</p>
+
+<p>Savery quaintly relates the action of his machine in &#8220;The
+Miner&#8217;s Friend,&#8221; and so exactly, that a better description
+could scarcely be asked: &#8220;The steam acts upon the surface
+of the water in the receiver, which surface only being heated
+by the steam, it does not condense, but the steam gravitates
+or presses with an elastic quality like air, and still increasing
+its elasticity or spring, until it counterpoises, or rather exceeds,
+the weight of the column of water in the force-pipe,
+which then it will necessarily drive up that pipe; the steam
+then takes some time to recover its power, but it will at last
+discharge the water out at the top of the pipe. You may
+see on the outside of the receiver how the water goes out,
+as well as if it were transparent; for, so far as the steam is
+contained within the vessel, it is dry without, and so hot as
+scarcely to endure the least touch of the hand; but so far
+as the water is inside the vessel, it will be cold and wet on
+the outside, where any water has fallen on it; which cold
+and moisture vanish as fast as the steam takes the place of
+the water in its descent.&#8221;</p>
+
+<p>After Savery&#8217;s death, in 1716, several of these engines
+were erected in which some improvements were introduced.
+Dr. Desaguliers, in 1718, built a Savery engine, in which he
+avoided some defects which he, with Dr. Gravesande, had<span class='pagenum'><a name="Page_42" id="Page_42">[42]</a></span>
+noted two years earlier. They had then proposed to adopt
+the arrangement of a single receiver which had been used
+by Savery himself, as already described, finding, by experiment
+on a model which they had made for the purpose,
+that one could be discharged three times, while the same
+boiler would empty two receivers but once each. In their
+arrangement, the steam was shut back in the boiler while
+the receiver was filling with water, and a high pressure thus
+accumulated, instead of being turned into the second receiver,
+and the pressure thus kept comparatively low.</p>
+
+<div class="figcenter"><a name="Fig14" id="Fig14"></a>
+<img src="images/illo069.png" alt="Papin's Two-Way Cock" width="350" height="280" />
+<p class="caption"><span class="smcap">Fig. 14.</span>&mdash;Papin&#8217;s Two-Way Cock.</p></div>
+
+<p>In the engine built in 1718, Desaguliers used a spherical
+boiler, which he provided with the lever safety-valve already
+applied by Papin, and adopted a comparatively small receiver&mdash;one-fifth
+the capacity of the boiler&mdash;of slender cylindrical
+form, and attached a pipe leading the water for
+condensation into the vessel, and effected its distribution by
+means of the &#8220;rose,&#8221; or a &#8220;sprinkling-plate,&#8221; such as is still
+frequently used in modern engines having jet-condensers.
+This substitution of jet for surface-condensation was of
+very great advantage, securing great promptness in the
+formation of a vacuum and a rapid filling of the receiver.
+A &#8220;<a href="#Fig14">two-way cock</a>&#8221; admitted steam to the receiver, or,
+being turned the other way, admitted the cold condensing
+water. The dispersion of the water in minute streams or
+drops was a very important detail, not only as securing great<span class='pagenum'><a name="Page_43" id="Page_43">[43]</a></span>
+rapidity of condensation, but enabling the designer to employ
+a comparatively small receiver or condenser.</p>
+
+<div class="figcenter"><a name="Fig15" id="Fig15"></a>
+<img src="images/illo070.png" alt="Desaguliers's Engine" width="350" height="424" />
+<p class="caption"><span class="smcap">Fig. 15.</span>&mdash;Engine built by
+Desaguliers in 1718.</p></div>
+
+<p>The engine is shown in <a href="#Fig15">Fig. 15</a>, which is copied from the
+&#8220;Experimental Philosophy&#8221; of Desaguliers.</p>
+
+<p>The receiver, <i>A</i>, is connected to the boiler, <i>B</i>, by a
+steam-pipe, <i>C</i>, terminating at the two-way cock, <i>D</i>; the
+&#8220;forcing-pipe,&#8221; <i>E</i>, has at its foot a check-valve, <i>F</i>, and the
+valve <i>G</i> is a similar check at the head of the suction-pipe.
+<i>H</i> is a strainer, to prevent the ingress of chips or other
+bodies carried to the pipe by the current; the cap above the
+valves is secured by a bridle, or stirrup, and screw, <i>I</i>, and
+may be readily removed to clear the valves or to renew
+them; <i>K</i> is the handle of the two-way cock; <i>M</i> is the injection-cock,
+and is kept open during the working of the
+engine; <i>L</i> is the chimney-flue; <i>N</i> and <i>O</i> are gauge-cocks
+fitted to pipes leading to the proper depths within the boiler,
+the water-line being somewhere between the levels of their
+lower ends; <i>P</i> is a lever safety-valve, as first used on the<span class='pagenum'><a name="Page_44" id="Page_44">[44]</a></span>
+&#8220;Digester&#8221; of Papin; <i>R</i> is the reservoir into which the
+water is pumped; <i>T</i> is the flue, leading spirally about the
+boiler from the furnace, <i>V</i>, to the chimney; <i>Y</i> is a cock
+fitted in a pipe through which the rising-main may be filled
+from the reservoir, should injection-water be needed when
+that pipe is empty.</p>
+
+<p>Seven of these engines were built, the first of which
+was made for the Czar of Russia. Its boiler had a capacity
+of &#8220;five or six hogsheads,&#8221; and the receiver, &#8220;holding one
+hogshead,&#8221; was filled and emptied four times a minute.
+The water was raised &#8220;by suction&#8221; 29 feet, and forced by
+steam pressure 11 feet higher.</p>
+
+<p>Another engine built at about this time, to raise water
+29 feet &#8220;by suction,&#8221; and to force it 24 feet higher, made
+6 &#8220;strokes&#8221; per minute, and, when forcing water but 6 or
+8 feet, made 8 or 9 strokes per minute. Twenty-five years
+later a workman overloaded the safety-valve of this engine,
+by placing the weight at the end and then adding &#8220;a very
+heavy plumber&#8217;s iron.&#8221; The boiler exploded, killing the
+attendant.</p>
+
+<p>Desaguliers says that one of these engines, capable of
+raising ten tons an hour 38 feet, in 1728 or 1729, cost &pound;80,
+exclusive of the piping.</p>
+
+<p>Blakely, in 1766, patented an improved Savery engine,
+in which he endeavored to avoid the serious loss due to condensation
+of the steam by direct contact with the water, by
+interposing a cushion of oil, which floated upon the water
+and prevented the contact of the steam with the surface of
+the water beneath it. He also used air for the same purpose,
+sometimes in double receivers, one supported on the
+other. These plans did not, however, prove satisfactory.</p>
+
+<p>Rigley, of Manchester, England, soon after erected
+Savery engines, and applied them to the driving of mills,
+by pumping water into reservoirs, from whence it returned
+to the wells or ponds from which it had been raised, turning
+water-wheels as it descended.</p>
+
+<p><span class='pagenum'><a name="Page_45" id="Page_45">[45]</a></span>Such an arrangement was in operation many years at
+the works of a Mr. Kiers, St. Pancras, London. It is described
+in detail, and illustrated, in Nicholson&#8217;s &#8220;Philosophical
+Journal,&#8221; vol. i., p. 419. It had a &#8220;wagon-boiler&#8221;
+7 feet long, 5 wide, and 5 deep; the wheel was
+18 feet in diameter, and drove the lathes and other
+machinery of the works. In this engine Blakely&#8217;s plan
+of injecting air was adopted. The injection-valve was
+a clack, which closed automatically when the vacuum was
+formed.</p>
+
+<p>The engine consumed 6 or 7 bushels of good coals, and
+made 10 strokes per minute, raising 70 cubic feet of water
+14 feet, and developing nearly 3 horse-power.</p>
+
+<p>Many years after Savery&#8217;s death, in 1774, Smeaton made
+the first duty-trials of engines of this kind. He found that
+an engine having a cylindrical receiver 16 inches in diameter
+and 22 feet high, discharging the water raised 14 feet above
+the surface of the water in the well, making 12 strokes, and
+raising 100 cubic feet per minute, developed 2<span class="enum">2</span>&#8725;<span class="denom">3</span> horse-power,
+and consumed 3 hundredweight of coals in four
+hours. Its duty was, therefore, 5,250,000 pounds raised one
+foot per bushel of 84 pounds of coals, or 62,500 &#8220;foot-pounds&#8221;
+of work per pound of fuel. An engine of slightly
+greater size gave a duty about 5 per cent. greater.</p>
+
+<p>When Louis XIV. revoked the edict of Nantes, by
+which Henry IV. had guaranteed protection to the Protestants
+of France, the terrible persecutions at once commenced
+drove from the kingdom some of its greatest men. Among
+these was Denys Papin.</p>
+
+<p>It was at about this time that the influence of the atmospheric
+pressure on the boiling-point began to be observed,
+Dr. Hooke having found that the boiling-point was
+a fixed temperature under the ordinary pressure of the atmosphere,
+and the increase in temperature and pressure of
+steam when confined having been shown by Papin with his
+&#8220;Digester.&#8221;</p>
+
+<div class="figcenter"><a name="Port3" id="Port3"></a>
+<img src="images/illo073.png" alt="Denys Papin" width="350" height="411" />
+<p class="caption">Denys Papin.</p></div>
+
+<p><span class='pagenum'><a name="Page_46" id="Page_46">[46]</a></span>
+<span class="smcap"><a href="#Port3">Denys Papin</a></span> was of a family which had attached itself
+to the Protestant Church; but he was given his education
+in the school of the Jesuits at Blois, and there acquired his
+knowledge of mathematics. His medical education was
+given him at Paris, although he probably received his degree
+at Orleans. He settled in Paris in 1672, with the
+intention of practising his profession, and devoted all his
+spare time, apparently, to the study of physics.</p>
+
+<p>Meantime, that distinguished philosopher, Huyghens,
+the inventor of the clock and of the gunpowder-engine, had
+been induced by the linen-draper&#8217;s apprentice, Colbert, now
+the most trusted adviser of the king, to take up his residence
+in Paris, and had been made one of the earliest members
+of the Academy of Science, which was founded at
+about that time. Papin became an assistant to Huyghens,<span class='pagenum'><a name="Page_47" id="Page_47">[47]</a></span>
+and aided him in his experiments in mechanics, having
+been introduced by Madame Colbert, who was also a native
+of Blois. Here he devised several modifications of the instruments
+of Guericke, and printed a description of them.<a name="FNanchor_25_25" id="FNanchor_25_25"></a><a href="#Footnote_25_25" class="fnanchor">[25]</a>
+This little book was presented to the Academy, and very
+favorably noticed. Papin now became well known among
+contemporary men of science at Paris, and was well received
+everywhere. Soon after, in the year 1675, as stated
+by the <i>Journal des Savants</i>, he left Paris and took up his
+residence in England, where he very soon made the acquaintance
+of Robert Boyle, the founder, and of the members
+of the Royal Society. Boyle speaks of Papin as having
+gone to England in the hope of finding a place in which he
+could satisfactorily pursue his favorite studies.</p>
+
+<p>Boyle himself had already been long engaged in the
+study of pneumatics, and had been especially interested in
+the investigations which had been original with Guericke.
+He admitted young Papin into his laboratory, and the
+two philosophers worked together at these attractive problems.
+It was while working with Boyle that Papin invented
+the double air-pump and the air-gun.</p>
+
+<p>Papin and his work had now become so well known,
+and he had attained so high a position in science, that he
+was nominated for membership in the Royal Academy, and
+was elected December 16, 1680. He at once took his place
+among the most talented and distinguished of the great
+men of his time.</p>
+
+<div class="figcenter"><a name="Fig16" id="Fig16"></a>
+<img src="images/illo075.png" alt="Digester" width="350" height="415" />
+<p class="caption"><span class="smcap">Fig. 16.</span>&mdash;Papin&#8217;s Digester, 1680.</p></div>
+
+<p>He probably invented his &#8220;Digester&#8221; while in England,
+and it was first described in a brochure written in English,
+under the title, &#8220;The New Digester.&#8221; It was subsequently
+published in Paris.<a name="FNanchor_26_26" id="FNanchor_26_26"></a><a href="#Footnote_26_26" class="fnanchor">[26]</a>
+This was a vessel, <i>B</i> (<a href="#Fig16">Fig. 16</a>), capable
+of being tightly closed by a screw, <i>D</i>, and a lid, <i>C</i>, in<span class='pagenum'><a name="Page_48" id="Page_48">[48]</a></span>
+which food could be cooked in water raised by a furnace,
+<i>A</i>, to the temperature due to any desired safe pressure of
+steam. The pressure was determined and limited by a
+weight, <i>W</i>, on the safety-valve lever, <i>G</i>. It is probable that
+this essential attachment to the steam-boiler had previously
+been used for other purposes; but Papin is given the
+credit of having first made use of it to control the pressure
+of steam.</p>
+
+<p>From England, Papin went to Italy, where he accepted
+membership and held official position in the Italian Academy
+of Science. Papin remained in Venice two years, and
+then returned to England. Here, in 1687, he announced one
+of his inventions, which is just becoming of great value in the
+arts. He proposed to transmit power from one point to another,
+over long distances, by the now well-known &#8220;pneumatic&#8221;
+method. At the point where power was available,<span class='pagenum'><a name="Page_49" id="Page_49">[49]</a></span>
+he exhausted a chamber by means of an air-pump, and, leading
+a pipe to the distant point at which it was to be utilized,
+there withdrew the air from behind a piston, and the pressure
+of the air upon the latter caused it to recede into the
+cylinder, in which it was fitted, raising a weight, of which
+the magnitude was proportionate to the size of the piston
+and the degree of exhaustion. Papin was not satisfactorily
+successful in his experiments; but he had created the germ
+of the modern system of pneumatic transmission of power.
+His disappointment at the result of his efforts to utilize
+the system was very great, and he became despondent, and
+anxious to change his location again.</p>
+
+<p>In 1687 he was offered the chair of Mathematics at
+Marburg by Charles, the Landgrave of Upper Hesse, and,
+accepting the appointment, went to Germany. He remained
+in Germany many years, and continued his researches with
+renewed activity and interest. His papers were published
+in the &#8220;Acta Eruditorum&#8221; at Leipsic, and in the &#8220;Philosophical
+Transactions&#8221; at London. It was while at Marburg
+that his papers descriptive of his method of pneumatic
+transmission of power were printed.<a name="FNanchor_27_27" id="FNanchor_27_27"></a><a href="#Footnote_27_27" class="fnanchor">[27]</a></p>
+
+<p>In the &#8220;Acta Eruditorum&#8221; of 1688 he exhibited a practicable
+plan, in which he exhausted the air from a set of
+engines or pumps by means of pumps situated at a long distance
+from the point of application of the power, and at the
+place where the prime mover&mdash;which was in this case a
+water-wheel&mdash;was erected.</p>
+
+<p>After his arrival at the University of Marburg, Papin
+exhibited to his colleagues in the faculty a modification of
+Huyghens&#8217;s gunpowder-engine, in which he had endeavored
+to obtain a more perfect vacuum than had Huyghens in the
+first of these machines. Disappointed in this, he finally
+adopted the expedient of employing steam to displace the<span class='pagenum'><a name="Page_50" id="Page_50">[50]</a></span>
+air, and to produce, by its condensation, the perfect vacuum
+which he sought; and he thus produced <i>the first steam-engine
+with a piston</i>, and the first piston steam-engine, in which
+condensation was produced to secure a vacuum. It was described
+in the &#8220;Acta&#8221; of Leipsic,<a name="FNanchor_28_28" id="FNanchor_28_28"></a><a href="#Footnote_28_28" class="fnanchor">[28]</a> in June, 1690, under the
+title, &#8220;Nova Methodus ad vires motrices validissimas leri
+pretio comparandeo&#8221; (&#8220;A New Method of securing cheaply
+Motive Power of considerable Magnitude&#8221;). He describes
+first the gunpowder-engine, and continues by stating that,
+&#8220;until now, all experiments have been unsuccessful; and
+after the combustion of the exploded powder, there always
+remains in the cylinder about one-fifth its volume of air.&#8221;
+He says that he has endeavored to arrive by another route
+at the same end; and &#8220;as, by a natural property of water,
+a small quantity of this liquid, vaporized by the action of
+heat, acquires an elasticity like that of the air, and returns
+to the liquid state again on cooling, without retaining the
+least trace of its elastic force,&#8221; he thought that it would be
+easy to construct machines in which, &#8220;by
+means of a moderate heat, and without
+much expense,&#8221; a more perfect vacuum
+could be produced than could be secured
+by the use of gunpowder.</p>
+
+<div class="figleft"><a name="Fig17" id="Fig17"></a>
+<img src="images/illo077.png" alt="Papin's Engine" width="183" height="350" />
+<p class="caption"><span class="smcap">Fig. 17.</span>&mdash;Papin&#8217;s Engine.</p></div>
+
+<p>The first machine of Papin (<a href="#Fig17">Fig. 17</a>)
+was very similar to the gunpowder-engine
+already described as the invention
+of Huyghens. In place of gunpowder, a
+small quantity of water is placed at the
+bottom of the cylinder, <i>A</i>; a fire is built
+beneath it, &#8220;the bottom being made of
+very thin metal,&#8221; and the steam formed
+soon raises the piston, <i>B</i>, to the top,
+where a latch, <i>E</i>, engaging a notch in
+the piston-rod, <i>H</i>, holds it up until it is desired that it shall<span class='pagenum'><a name="Page_51" id="Page_51">[51]</a></span>
+drop. The fire being removed, the steam condenses, and a
+vacuum is formed below the piston, and the latch, <i>E</i>, being
+disengaged, the piston is driven down by the superincumbent
+atmosphere and raises the weight which has been, meantime,
+attached to a rope, <i>L</i>, passing from the piston-rod over pulleys,
+<i>T T</i>. The machine had a cylinder two and a half inches
+in diameter, and raised 60 pounds once a minute; and
+Papin calculated that a machine of a little more than two
+feet diameter of cylinder and of four feet stroke would raise
+8,000 pounds four feet per minute&mdash;i. e., that it would yield
+about one horse-power.</p>
+
+<p>The inventor claimed that this new machine would be
+found useful in relieving mines from water, in throwing
+bombs, in ship-propulsion, attaching revolving paddles&mdash;i. e.,
+paddle-wheels&mdash;to the sides of the vessel, which wheels were
+to be driven by several of his engines, in order to secure
+continuous motion, the piston-rods being fitted with racks
+which were to engage ratchet-wheels on the paddle-shafts.</p>
+
+<p>&#8220;The principal difficulty,&#8221; he says, answering anticipated
+objections, &#8220;is that of making these large cylinders.&#8221;</p>
+
+<p>In a reprint describing his invention, in 1695, Papin
+gives a description of a &#8220;newly-invented furnace,&#8221; a kind
+of fire-box steam-boiler, in which the fire, completely surrounded
+by water, makes steam so rapidly that his engine
+could be driven at the rate of four strokes per minute by
+the steam supplied by it.</p>
+
+<p>Papin also proposed the use of a peculiar form of furnace
+with this engine, which, embodying as it does some
+suggestions that very probably have since been attributed
+to later inventors, deserves special notice. In this furnace,
+Papin proposed to burn his fuel on a grate within a furnace
+arranged with a <i>down-draught</i>, the air entering above the
+grate, passing <i>down</i> through the fire, and from the ash-pit
+through a side flue to the chimney. In starting the fire,
+the coal was laid on the grate, covered with wood, and the
+latter was ignited, the flame, passing downward through the<span class='pagenum'><a name="Page_52" id="Page_52">[52]</a></span>
+coal, igniting that in turn, and, as claimed by Papin, the
+combustion was complete, and the formation of smoke was
+entirely prevented. He states, in &#8220;Acta Eruditorum,&#8221;
+that the heat was intense, the saving of fuel very great,
+and that the only difficulty was to find a refractory material
+which would withstand the high temperature attained.</p>
+
+<p>This is the first fire-box and flue boiler of which we have
+record. The experiment is supposed to have led Papin to
+suggest the use of a hot-blast, as practised by Neilson more
+than a century later, for reducing metals from their ores.</p>
+
+<p>Papin made another boiler having a flue winding through
+the water-space, and presenting a heating surface of nearly
+80 square feet. The flue had a length of 24 feet, and
+was about 10 inches square. It is not stated what were
+the maximum pressures carried on these boilers; but it
+is known that Papin had used very high pressures in his
+digesters&mdash;probably between 1,200 and 1,500 pounds per
+square inch.</p>
+
+<p>In the year 1705, Leibnitz, then visiting England, had
+seen a Savery engine, and, on his return, described it to
+Papin, sending him a sketch of the machine. Papin read
+the letter and exhibited the sketch to the Landgrave of
+Hesse, and Charles at once urged him to endeavor to perfect
+his own machine, and to continue the researches which he
+had been intermittently pursuing since the earlier machine
+had been exhibited in public.</p>
+
+<p>In a small pamphlet printed at Cassel in 1707,<a name="FNanchor_29_29" id="FNanchor_29_29"></a><a href="#Footnote_29_29"
+class="fnanchor">[29]</a> Papin
+describes a new form of engine, in which he discards the
+original plan of a modified Huyghens engine, with tight-fitting
+piston and cylinder, raising its load by indirect action,
+and makes a modified Savery engine, which he calls
+the &#8220;Elector&#8217;s Engine,&#8221; in honor of his patron. This is
+the engine shown in the engraving, and as proposed to be
+used by him in turning a water-wheel.</p>
+
+<div class="figcenter"><a name="Fig18" id="Fig18"></a>
+<img src="images/illo080.png" alt="Papin's Engine with Water-Wheel" width="600" height="331" />
+<p class="caption"><span class="smcap">Fig. 18.</span>&mdash;Papin&#8217;s Engine and Water-Wheel,
+<span class="smcap">a. d.</span> 1707.</p></div>
+
+<p><span class='pagenum'><a name="Page_53" id="Page_53">[53]</a></span>The sketch is that given by the inventor in his memoir.
+It consists (<a href="#Fig18">Fig. 18</a>) of a steam-boiler, <i>a</i>, from which steam is
+led through the cock, <i>c</i>, to the working cylinder, <i>n n</i>. The water
+beneath the floating-piston, <i>h</i>, which latter serves simply as
+a cushion to protect the steam from sudden condensation or
+contact with the water, is forced into the vessel <i>r r</i>, which
+is a large air-chamber, and which serves to render the outflow
+of water comparatively uniform, and the discharge occurs
+by means of the pipe <i>q</i>, from which the water rises to
+the desired height. A fresh supply of water is introduced
+through the funnel <i>k</i>, after condensation of the steam in <i>n n</i>,
+and the operation of expulsion is repeated.</p>
+
+<p>This machine is evidently a retrogression, and Papin,
+after having earned the honor of having invented the first
+steam-engine of the typical form which has since become
+so universally applied, forfeited that credit by his evident
+ignorance of its superiority over existing devices, and by
+attempting unsuccessfully to perfect the inferior device of
+another inventor.</p>
+
+<p>Subsequently, Papin made an attempt to apply the
+steam-engine to the propulsion of vessels, the account of
+which will be given in the chapter on Steam-Navigation.</p>
+
+<p>Again disappointed, Papin once more visited England,<span class='pagenum'><a name="Page_54" id="Page_54">[54]</a></span>
+to renew his acquaintance with the <i>savans</i> of the Royal
+Society; but Boyle had died during the period which Papin
+had spent in Germany, and the unhappy and disheartened
+inventor and philosopher died in 1810, without having
+seen any one of his many devices and ingenious inventions
+a practical success.</p>
+
+<hr class="l05" />
+<div class="colleft">
+<div class="footnote"><p class="left"><a name="Footnote_6_6" id="Footnote_6_6"></a><a href="#FNanchor_6_6"><span class="label">&nbsp;[6]</span></a>
+The British Museum contains four manuscript copies of Hero&#8217;s &#8220;Pneumatics,&#8221;
+which were written in the fifteenth and sixteenth centuries. These
+manuscripts have been examined with great care, and a translation from
+them prepared by Prof. J. G. Greenwood, and published at the desire
+of Mr. Bennett Woodcroft, the author of a valuable little treatise on
+&#8220;Steam Navigation.&#8221; This is, so far as the author is aware, the only
+existing English translation of any portion of Hero&#8217;s works.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_7_7" id="Footnote_7_7"></a><a href="#FNanchor_7_7"><span class="label">&nbsp;[7]</span></a>
+Stuart&#8217;s &#8220;Anecdotes.&#8221;</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_8_8" id="Footnote_8_8"></a><a href="#FNanchor_8_8"><span class="label">&nbsp;[8]</span></a>
+&#8220;Berg-Postilla, oder Sarepta von Bergwerk und Metallen.&#8221; Nuremberg,
+1571.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_9_9" id="Footnote_9_9"></a><a
+href="#FNanchor_9_9"><span class="label">&nbsp;[9]</span></a>
+&#8220;History of the Steam-Engine,&#8221; 1825.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_10_10" id="Footnote_10_10"></a><a
+href="#FNanchor_10_10"><span class="label">[10]</span></a>
+&#8220;Theatrum Instrumentorum et Machinarum, Jacobi Bessoni, cum
+Franc Beroaldus, figuarum declaratione demonstrativa.&#8221; Lugduni, 1578.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_11_11" id="Footnote_11_11"></a><a
+href="#FNanchor_11_11"><span class="label">[11]</span></a>
+&#8220;Le diverse et artificiose machine del Capitano Agostino Ramelli,
+del Ponte della Prefia.&#8221; Paris, 1588.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_12_12" id="Footnote_12_12"></a><a
+href="#FNanchor_12_12"><span class="label">[12]</span></a>
+&#8220;Pneumaticorum libri tres,&#8221; etc., 4to. Naples, 1601. &#8220;I Tre Libri
+de&#8217; Spiritali.&#8221; Napoli, 1606.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_13_13" id="Footnote_13_13"></a><a
+href="#FNanchor_13_13"><span class="label">[13]</span></a>
+&#8220;Le Machine deverse del Signior Giovanni Branca, cittadino Romano,
+Ingegniero, Architetto della Sta. Casa di Loretto.&#8221; Roma, MDCXXIX.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_14_14" id="Footnote_14_14"></a><a
+href="#FNanchor_14_14"><span class="label">[14]</span></a>
+Rymer&#8217;s &#8220;F&oelig;dera,&#8221; Sanderson. Ewbank&#8217;s &#8220;Hydraulics,&#8221;
+p. 419.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_15_15" id="Footnote_15_15"></a><a
+href="#FNanchor_15_15"><span class="label">[15]</span></a>
+&#8220;Anecdotes of the Steam-Engine,&#8221; vol. i., p. 61.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_16_16" id="Footnote_16_16"></a><a
+href="#FNanchor_16_16"><span class="label">[16]</span></a>
+Stuart&#8217;s &#8220;Anecdotes.&#8221;</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_17_17" id="Footnote_17_17"></a><a
+href="#FNanchor_17_17"><span class="label">[17]</span></a>
+&#8220;Pendule Perpetuelle, avec la mani&egrave;re d&#8217;&eacute;lever d&#8217;eau par le moyen de
+la poudre &agrave; canon,&#8221; Paris, 1678.</p></div>
+</div>
+
+<div class="footnote"><p class="left"><a name="Footnote_18_18" id="Footnote_18_18"></a><a
+href="#FNanchor_18_18"><span class="label">[18]</span></a>
+&#8220;Elevation des Eaux par toute sorte de Machines r&eacute;duite &agrave; la Mesure
+au Poids et &agrave; la Balance, pr&eacute;sent&eacute;e a Sa Majest&eacute; Tr&egrave;s Chr&eacute;tienne, par le
+Chevalier Morland, Gentilhomme Ordinaire de la Chambre Priv&eacute;e et Maistre
+de Mechaniques du Roy de la Grande Bretagne, 1683.&#8221;</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_19_19" id="Footnote_19_19"></a><a
+href="#FNanchor_19_19"><span class="label">[19]</span></a>
+&#8220;Les Principes de la Nouvelle Force de Feu, invent&eacute;e par le Chevalier
+Morland, l&#8217;an 1682, et pr&eacute;sent&eacute;e a Sa Majest&eacute; Tr&egrave;s Chr&eacute;tienne, 1683.&#8221;</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_20_20" id="Footnote_20_20"></a><a
+href="#FNanchor_20_20"><span class="label">[20]</span></a>
+Harris, &#8220;Lexicon Technicum,&#8221; London, 1710.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_21_21" id="Footnote_21_21"></a><a
+href="#FNanchor_21_21"><span class="label">[21]</span></a>
+&#8220;Navigation Improved; or, The Art of Rowing Ships of all rates in
+Calms, with a more Easy, Swift, and Steady Motion, than Oars can,&#8221; etc.,
+etc. By Thomas Savery, Gent. London, 1698.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_22_22" id="Footnote_22_22"></a><a
+href="#FNanchor_22_22"><span class="label">[22]</span></a>
+&#8220;Experimental Philosophy,&#8221; vol. ii., p. 465.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_23_23" id="Footnote_23_23"></a><a
+href="#FNanchor_23_23"><span class="label">[23]</span></a>
+&#8220;Philosophical Transactions, No. 252.&#8221; Weld&#8217;s &#8220;Royal Society,&#8221; vol.
+i., p. 357. Lowthorp&#8217;s &#8220;Abridgment,&#8221; vol. i.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_24_24" id="Footnote_24_24"></a><a
+href="#FNanchor_24_24"><span class="label">[24]</span></a>
+Bradley, &#8220;New Improvements of Planting and Gardening.&#8221; Switzer,
+&#8220;Hydrostatics,&#8221; 1729.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_25_25" id="Footnote_25_25"></a><a
+href="#FNanchor_25_25"><span class="label">[25]</span></a>
+&#8220;Nouvelles Exp&eacute;riences du Vuide, avec la description des Machines
+qui servent &agrave; le faire.&#8221; Paris, 1674.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_26_26" id="Footnote_26_26"></a><a
+href="#FNanchor_26_26"><span class="label">[26]</span></a>
+&#8220;La mani&egrave;re d&#8217;amollir les os et de faire cuire toutes sortes de viandes,&#8221;
+etc.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_27_27" id="Footnote_27_27"></a><a
+href="#FNanchor_27_27"><span class="label">[27]</span></a>
+&#8220;Recueil des diverses Pieces touchant quelques Nouvelles Machines et
+autres Sujets Philosophiques,&#8221; M. D. Papin. Cassel, 1695.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_28_28" id="Footnote_28_28"></a><a
+href="#FNanchor_28_28"><span class="label">[28]</span></a>
+&#8220;Acta Eruditorum,&#8221; Leipsic, 1690.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_29_29" id="Footnote_29_29"></a><a
+href="#FNanchor_29_29"><span class="label">[29]</span></a>
+&#8220;Nouvelle mani&egrave;re d&#8217;&eacute;lever l&#8217;Eau par la Force du Feu, mis en Lumi&egrave;re,&#8221;
+par D. Papin. Cassel, 1707.</p></div>
+
+<hr class="l05" />
+<p>&nbsp;</p>
+<div class="figcenter"><img src="images/illo081.png" alt="Ornament" width="200" height="272" /></div>
+<p>&nbsp;</p>
+
+<hr class="c40" /><p class='pagenum'><a name="Page_55" id="Page_55">[55]</a></p>
+<h2><a name="CHAPTER_II" id="CHAPTER_II"></a>CHAPTER II.</h2>
+
+<h3><i>THE STEAM-ENGINE AS A TRAIN OF MECHANISM.</i></h3>
+<hr class="c05" />
+
+<div class="blockquot"><p>&#8220;The introduction of new Inventions seemeth to be the very chief of
+all human Actions. The Benefits of new Inventions may extend to all
+Mankind universally; but the Good of political Achievements can respect
+but some particular Cantons of Men; these latter do not endure above a
+few Ages, the former forever. Inventions make all Men happy, without
+either Injury or Damage to any one single Person. Furthermore, new
+Inventions are, as it were, new Erections and Imitations of God&#8217;s own
+Works.&#8221;&mdash;<span class="smcap">Bacon.</span></p></div>
+
+<hr class="c05" />
+<h4><span class="smcap">The Modern Type, as Developed by Newcomen,
+Beighton, and Smeaton.</span></h4>
+<hr class="c05" />
+
+<p>At the beginning of the eighteenth century every element
+of the modern type of steam-engine had been separately
+invented and practically applied. The character of
+atmospheric pressure, and of the pressure of gases, had become
+understood. The nature of a vacuum was known,
+and the method of obtaining it by the displacement of the
+air by steam, and by the condensation of the vapor, was
+understood. The importance of utilizing the power of steam,
+and the application of condensation in the removal of atmospheric
+pressure, was not only recognized, but had been
+actually and successfully attempted by Morland, Papin,
+and Savery.</p>
+
+<p>Mechanicians had succeeded in making steam-boilers
+capable of sustaining any desired or any useful pressure,
+and Papin had shown how to make them comparatively safe<span class='pagenum'><a name="Page_56" id="Page_56">[56]</a></span>
+by the attachment of the safety-valve. They had made
+steam-cylinders fitted with pistons, and had used such a
+combination in the development of power.</p>
+
+<p>It now only remained for the engineer to combine known
+forms of mechanism in a practical machine which should be
+capable of economically and conveniently utilizing the power
+of steam through the application of now well-understood
+principles, and by the intelligent combination of physical
+phenomena already familiar to scientific investigators.</p>
+
+<p>Every essential fact and every vital principle had been
+learned, and every one of the needed mechanical combinations
+had been successfully effected. It was only requisite
+that an inventor should appear, capable of perceiving that
+these known facts and combinations of mechanism, properly
+illustrated in a working machine, would present to the
+world its greatest physical blessing.</p>
+
+<p>The defects of the simple engines constructed up to this
+time have been noted as each has been described. None of
+them could be depended upon for safe, economical, and continuous
+work. Savery&#8217;s was the most successful of all. But
+the engine of Savery, even with the improvements of Desaguliers,
+was unsafe where most needed, because of the
+high pressures necessarily carried in its boilers when pumping
+from considerable depths; it was uneconomical, in consequence
+of the great loss of heat in its forcing-cylinders
+when the hot steam was surrounded at its entrance by colder
+bodies; it was slow in operation, of great first cost, and
+expensive in first cost and in repairs, as well as in its operation.
+It could not be relied upon to do its work uninterruptedly,
+and was thus in many respects a very unsatisfactory
+machine.</p>
+
+<p>The man who finally effected a combination of the elements
+of the modern steam-engine, and produced a machine
+which is unmistakably a true engine&mdash;i. e., a train of mechanism
+consisting of several elementary pieces combined in
+a train capable of transmitting a force applied at one end<span class='pagenum'><a name="Page_57" id="Page_57">[57]</a></span>
+and of communicating it to the resistance to be overcome
+at the other end&mdash;was <span class="smcap">Thomas Newcomen</span>, an &#8220;iron-monger&#8221;
+and blacksmith of Dartmouth, England. The engine
+invented by him, and known as the &#8220;Atmospheric Steam-Engine,&#8221;
+is the first of an entirely new type.</p>
+
+<p>The old type of engine&mdash;the steam-engine as a simple
+machine&mdash;had been given as great a degree of perfection,
+by the successive improvements of Worcester, Savery, and
+Desaguliers, as it was probably capable of attaining by any
+modification of its details. The next step was necessarily
+a complete change of type; and to effect such a change, it
+was only necessary to combine devices already known and
+successfully tried.</p>
+
+<p>But little is known of the personal history of Newcomen.
+His position in life was humble, and the inventor
+was not then looked upon as an individual of even possible
+importance in the community. He was considered as one
+of an eccentric class of schemers, and of an order which,
+concerning itself with mechanical matters, held the lowest
+position in the class.</p>
+
+<p>It is supposed that Savery&#8217;s engine was perfectly well
+known to Newcomen, and that the latter may have visited
+Savery at his home in Modbury, which was but fifteen
+miles from the residence of Newcomen. It is thought, by
+some biographers of these inventors, that Newcomen was
+employed by Savery in making the more intricate forgings
+of his engine. Harris, in his &#8220;Lexicon Technicum,&#8221; states
+that drawings of the engine of Savery came into the hands
+of Newcomen, who made a model of the machine, set it up
+in his garden, and then attempted its improvement; but
+Switzer says that Newcomen &#8220;was as early in his invention
+as Mr. Savery was in his.&#8221;</p>
+
+<p>Newcomen was assisted in his experiments by John Calley,
+who, with him, took out the patent. It has been stated
+that a visit to Cornwall, where they witnessed the working
+of a Savery engine, first turned their attention to the subject;<span class='pagenum'><a name="Page_58" id="Page_58">[58]</a></span>
+but a friend of Savery has stated that Newcomen
+was as early with his general plans as Savery.</p>
+
+<p>After some discussion with Calley, Newcomen entered
+into correspondence with Dr. Hooke, proposing a steam-engine
+to consist of a <i>steam-cylinder containing a piston
+similar to that of Papin&#8217;s, and to drive a separate pump</i>,
+similar to those generally in use where water was raised by
+horse or wind power. Dr. Hooke advised and argued strongly
+against their plan, but, fortunately, the obstinate belief
+of the unlearned mechanics was not overpowered by the
+disquisitions of their distinguished correspondent, and Newcomen
+and Calley attempted an engine on their peculiar
+plan. This succeeded so well as to induce them to continue
+their labors, and, in 1705, to patent,<a name="FNanchor_30_30" id="FNanchor_30_30"></a><a href="#Footnote_30_30" class="fnanchor">[30]</a> in combination with
+Savery&mdash;who held the exclusive right to practise surface-condensation,
+and who induced them to allow him an interest
+with them&mdash;an engine combining a steam-cylinder and
+piston, surface-condensation, a separate boiler, and separate
+pumps.</p>
+
+<div class="figcenter"><a name="Fig19" id="Fig19"></a>
+<img src="images/illo086.png" alt="Newcomen's Engine" width="400" height="455" />
+<p class="caption"><span class="smcap">Fig. 19.</span>&mdash;Newcomen&#8217;s Engine, <span class="smcap">a. d.</span> 1705.</p></div>
+
+<p>In the atmospheric-engine, as first designed, the slow
+process of condensation by the application of the condensing
+water to the exterior of the cylinder, to produce the
+vacuum, caused the strokes of the engine to take place at
+very long intervals. An improvement was, however, soon
+effected, which immensely increased the rapidity of condensation.
+A jet of water was thrown directly <i>into</i> the
+cylinder, thus effecting for the Newcomen engine just
+what Desaguliers had done for the Savery engine previously.
+As thus improved, the Newcomen engine is shown
+in <a href="#Fig19">Fig. 19</a>.</p>
+
+<p>Here <i>b</i> is the boiler. Steam passes from it through the
+cock, <i>d</i>, and up into the cylinder, <i>a</i>, equilibrating the pressure
+of the atmosphere, and allowing the heavy pump-rod, <i>k</i>, to<span class='pagenum'><a name="Page_59" id="Page_59">[59]</a></span>
+fall, and, by the greater weight acting through the beam, <i>i i</i>,
+to raise the piston, <i>s</i>, to the position shown. The rod <i>m</i> carries
+a counterbalance, if needed. The cock <i>d</i> being shut, <i>f</i>
+is then opened, and a jet of water from the reservoir, <i>g</i>, enters
+the cylinder, producing a vacuum by the condensation
+of the steam. The pressure of the air above the piston now
+forces it down, again raising the pump-rods, and thus the
+engine works on indefinitely.</p>
+
+<p>The pipe <i>h</i> is used for the purpose of keeping the upper
+side of the piston covered with water, to prevent air-leaks&mdash;a
+device of Newcomen. Two gauge-cocks, <i>c c</i>, and a safety-valve,
+<i>N</i>, are represented in the figure, but it will be noticed
+that the latter is quite different from the now usual form.
+Here, the pressure used was hardly greater than that of the
+atmosphere, and the weight of the valve itself was ordinarily
+sufficient to keep it down. The condensing water, together
+with the water of condensation, flows off through
+the open pipe <i>p</i>. Newcomen&#8217;s first engine made 6 or 8<span class='pagenum'><a name="Page_60" id="Page_60">[60]</a></span>
+strokes a minute; the later and improved engines made 10
+or 12.</p>
+
+<p>The steam-engine has now assumed a form that somewhat
+resembles the modern machine.</p>
+
+<p>The Newcomen engine is seen at a glance to have been
+a combination of earlier ideas. It was the engine of Huyghens,
+with its cylinder and piston as improved by Papin,
+by the substitution of steam for the gases generated by the
+explosion of gunpowder; still further improved by Newcomen
+and Calley by the addition of the method of condensation
+used in the Savery engine. It was further modified,
+with the object of applying it directly to the working
+of the pumps of the mines by the introduction of the overhead
+beam, from which the piston was suspended at one
+end and the pump-rod at the other.</p>
+
+<p>The advantages secured by this combination of inventions
+were many and manifest. The piston not only gave
+economy by interposing itself between the impelling and
+the resisting fluid, but, by affording opportunity to make
+the area of piston as large as desired, it enabled Newcomen
+to use any convenient pressure and any desired proportions
+for any proposed lift. The removal of the water to be
+lifted from the steam-engine proper and handling it with
+pumps, was an evident cause of very great economy of
+steam.</p>
+
+<p>The disposal of the water to be raised in this way also
+permitted the operations of condensation of steam, and the
+renewal of pressure on the piston, to be made to succeed
+each other with rapidity, and enabled the inventor to choose,
+unhampered, the device for securing promptly the action of
+condensation.</p>
+
+<p>Desaguliers, in his account of the introduction of the
+engine of Newcomen, says that, with his coadjutor Calley,
+he &#8220;made several experiments in private about the year
+1710, and in the latter end of the year 1711 made proposals
+to drain the water of a colliery at Griff, in Warwickshire,<span class='pagenum'><a name="Page_61" id="Page_61">[61]</a></span>
+where the proprietors employed 500 horses, at an expense
+of &pound;900 a year; but, their invention not meeting with the
+reception they expected, in March following, through the
+acquaintance of Mr. Potter, of Bromsgrove, in Worcestershire,
+they bargained to draw water for Mr. Back, of
+Wolverhampton, where, after a great many laborious attempts,
+they did make the engine work; but, not being
+either philosophers to understand the reason, or mathematicians
+enough to calculate the powers and proportions of
+the parts, they very luckily, by accident, found what they
+sought for.</p>
+
+<p>&#8220;They were at a loss about the pumps, but, being so
+near Birmingham, and having the assistance of so many admirable
+and ingenious workmen, they came, about 1712, to
+the method of making the pump-valves, clacks, and buckets,
+whereas they had but an imperfect notion of them before.
+One thing is very remarkable: as they were at first working,
+they were surprised to see the engine go several strokes,
+and very quick together, when, after a search, they found a
+hole in the piston, which let the cold water in to condense
+the steam in the inside of the cylinder, whereas, before, they
+had always done it on the outside. They used before to
+work with a buoy to the cylinder, inclosed in a pipe, which
+buoy rose when the steam was strong and opened the injection,
+and made a stroke; thereby they were only capable
+of giving 6, 8, or 10 strokes in a minute, till a boy, named
+Humphrey Potter, in 1713, who attended the engine, added
+(what he called a <i>scoggan</i>) a catch, that the beam always
+opened, and then it would go 15 or 16 strokes a minute.
+But, this being perplexed with catches and strings, Mr.
+Henry Beighton, in an engine he had built at Newcastle-upon-Tyne
+in 1718, took them all away but the beam itself,
+and supplied them in a much better manner.&#8221;</p>
+
+<p>In illustration of the application of the Newcomen engine
+to the drainage of mines, Farey describes a small
+machine, of which the pump is 8 inches in diameter, and<span class='pagenum'><a name="Page_62" id="Page_62">[62]</a></span>
+the lift 162 feet. The column of water to be raised weighed
+3,535 pounds. The steam-piston was made 2 feet in diameter,
+giving an area of 452 square inches. The net working-pressure
+was assumed at 10<span class="enum">3</span>&#8725;<span class="denom">4</span> pounds per square inch; the
+temperature of the water of condensation and of uncondensed
+vapor after the entrance of the injection-water being
+usually about 150&deg; Fahr. This gave an excess of pressure
+on the steam-side of 1,324 pounds, the total pressure on the
+piston being 4,859 pounds. One-half of this excess is counterweighted
+by the pump-rods, and by weight on that end
+of the beam; and the weight, 662 pounds, acting on each
+side alternately as a surplus, produced the requisite rapidity
+of movement of the machine. This engine was said to
+make 15 strokes per minute, giving a speed of piston of 75
+feet per minute, and the power exerted usefully was equivalent
+to 265,125 pounds raised one foot high per minute.
+As the horse-power is equivalent to 33,000 &#8220;foot-pounds&#8221;
+per minute, the engine was of <span class="enum">265125</span>&#8725;
+<span class="denom">33000</span> = 8.034&mdash;almost exactly
+8 horse-power.</p>
+
+<div class="figcenter"><a name="Fig20" id="Fig20"></a>
+<img src="images/illo090.png" alt="Beighton's Valve Gear" width="350" height="491" />
+<p class="caption"><span class="smcap">Fig. 20.</span>&mdash;Beighton&#8217;s Valve-Gear, <span class="smcap">a. d.</span> 1718.</p></div>
+
+<p>It is instructive to contrast this estimate with that made
+for a Savery engine doing the same work. The latter would
+have raised the water about 26 feet in its &#8220;suction-pipe,&#8221;
+and would then have forced it, by the direct pressure of
+steam, the remaining distance of 136 feet; and the steam-pressure
+required would have been nearly 60 pounds per
+square inch. With this high temperature and pressure, the
+waste of steam by condensation in the forcing-vessels would
+have been so great that it would have compelled the adoption
+of two engines of considerable size, each lifting the
+water one-half the height, and using steam of about 25
+pounds pressure. Potter&#8217;s rude valve-gear was soon improved
+by Henry Beighton, in an engine which that talented
+engineer erected at Newcastle-upon-Tyne in 1718, and in
+which he substituted substantial materials for the cords, as
+in <a href="#Fig20">Fig. 20</a>.</p>
+
+<p>In this sketch, <i>r</i> is a plug-tree, plug-rod, or plug-frame,<span class='pagenum'><a name="Page_63" id="Page_63">[63]</a></span>
+as it is variously called, suspended from the great beam,
+with which it rises and falls, bringing the pins <i>p</i> and <i>k</i>, at
+the proper moment, in contact with the handles <i>k k</i> and <i>n n</i>
+of the valves, moving them in the proper direction and to
+the proper extent. A lever safety-valve is here used, at
+the suggestion, it is said, of Desaguliers. The piston was
+packed with leather or with rope, and lubricated with tallow.</p>
+
+<p>After the death of Beighton, the atmospheric engine of
+Newcomen retained its then standard form for many years,
+and came into extensive use in all the mining districts, particularly
+in Cornwall, and was also applied occasionally to
+the drainage of wet lands, to the supply of water to towns,
+and it was even proposed by Hulls to be used for ship-propulsion.<span class='pagenum'><a name="Page_64" id="Page_64">[64]</a></span></p>
+
+<p>The proportions of the engines had been determined in a
+hap-hazard way, and they were in many cases very unsafe.
+John Smeaton, the most distinguished engineer of his time,
+finally, in 1769, experimentally determined proper proportions,
+and built several of these engines of very considerable
+size. He built his engines with steam-cylinders of
+greater length of stroke than had been customary, and gave
+them such dimensions as, by giving a greater excess of
+pressure on the steam-side, enabled him to obtain a greatly-increased
+speed of piston. The first of his new style of engine
+was erected at Long Benton, near Newcastle-upon-Tyne,
+in 1774.</p>
+
+<p><a href="#Fig21">Fig. 21</a><a name="FNanchor_31_31" id="FNanchor_31_31"></a><a href="#Footnote_31_31" class="fnanchor">[31]</a>
+illustrates its principal characteristic features.
+The boiler is not shown.</p>
+
+<div class="figcenter"><a name="Fig21" id="Fig21"></a>
+<img src="images/illo092.png" alt="Smeaton's Newcomen Engine" width="284" height="450" />
+<p class="caption"><span class="smcap">Fig. 21.</span>&mdash;Smeaton&#8217;s Newcomen Engine.</p>
+<p class="center fsize80"><a href="images/large092.jpg">Large scale image.</a></p></div>
+
+<p>The steam is led to the engine through the pipe, <i>C</i>, and
+is regulated by turning the cock in the receiver, <i>D</i>, which
+connects with the steam-cylinder by the pipe, <i>E</i>, which
+latter pipe rises a little way above the bottom of the cylinder,
+<i>F</i>, in order that it may not drain off the injection-water
+into the steam-pipe and receiver.</p>
+
+<p>The steam-cylinder, about ten feet in length, is fitted
+with a carefully-made piston, <i>G</i>, having a flanch rising four
+or five inches and extending completely around its circumference,
+and nearly in contact with the interior surface of
+the cylinder. Between this flanch and the cylinder is driven
+a &#8220;packing&#8221; of oakum, which is held in place by weights;
+this prevents the leakage of air, water, or steam, past the
+piston, as it rises and falls in the cylinder at each stroke of
+the engine. The chain and piston-rod connect the piston
+to the beam, <i>I I</i>. The arch-heads at each end of the beam
+keep the chains of the piston-rod and the pump-rods perpendicular
+and in line.</p>
+
+<p>A &#8220;jack-head&#8221; pump, <i>N</i>, is driven by a small beam deriving
+its motion from the plug-rod at <i>g</i>, raises the water<span class='pagenum'><a name="Page_65" id="Page_65">[65]</a></span>
+required for condensing the steam, and keeps the cistern, <i>O</i>,
+supplied. This &#8220;jack-head cistern&#8221; is sufficiently elevated
+to give the water entering the cylinder the velocity requisite
+to secure prompt condensation. A waste-pipe carries away
+any surplus water. The injection-water is led from the cistern
+by the pipe, <i>P P</i>, which is two or three inches in diameter,<span class='pagenum'><a name="Page_66" id="Page_66">[66]</a></span>
+and the flow of water is regulated by the injection-cock,
+<i>r</i>. The cap at the end, <i>d</i>, is pierced with several holes,
+and the stream thus divided rises in jets when admitted,
+and, striking the lower side of the piston, the spray thus
+produced very rapidly condenses the steam, and produces a
+vacuum beneath the piston. The valve, <i>e</i>, on the upper end
+of the injection-pipe, is a check-valve, to prevent leakage
+into the engine when the latter is not in operation. The
+little pipe, <i>f</i>, supplies water to the upper side of the piston,
+and, keeping it flooded, prevents the entrance of air when
+the packing is not perfectly tight.</p>
+
+<p>The &#8220;working-plug,&#8221; or plug-rod, <i>Q</i>, is a piece of timber
+slit vertically, and carrying pins which engage the
+handles of the valves, opening and closing them at the
+proper times. The steam-cock, or regulator, has a handle,
+<i>h</i>, by which it is moved. The iron rod, <i>i i</i>, or spanner, gives
+motion to the handle, <i>h</i>.</p>
+
+<p>The vibrating lever, <i>k l</i>, called the <i>Y</i>, or the &#8220;tumbling-bob,&#8221;
+moves on the pins, <i>m n</i>, and is worked by the levers,
+<i>o p</i>, which in turn are moved by the plug-tree. When <i>o</i>
+is depressed, the loaded end, <i>k</i>, is given the position seen in
+the sketch, and the leg <i>l</i> of the <i>Y</i> strikes the spanner, <i>i i</i>,
+and, opening the steam-valve, the piston at once rises as
+steam enters the cylinder, until another pin on the plug-rod
+raises the piece, <i>P</i>, and closes the regulator again. The
+lever, <i>q r</i>, connects with the injection-cock, and is moved,
+when, as the piston rises, the end, <i>q</i>, is struck by a pin on
+the plug-rod, and the cock is opened and a vacuum produced.
+The cock is closed on the descent of the plug-tree
+with the piston. An eduction-pipe, <i>R</i>, fitted with a clock,
+conveys away the water in the cylinder at the end of each
+down-stroke; the water thus removed is collected in the
+hot-well, <i>S</i>, and is used as feed-water for the boiler, to which
+it is conveyed by the pipe <i>T</i>. At each down-stroke, while
+the water passes out through <i>R</i>, the air which may have
+collected in the cylinder is driven out through the &#8220;snifting-valve,&#8221;
+<span class='pagenum'><a name="Page_67" id="Page_67">[67]</a></span>
+<i>s</i>. The steam-cylinder is supported on strong
+beams, <i>t t</i>; it has around its upper edge a guard, <i>v</i>, of lead,
+which prevents the overflow of the water on the top of the
+piston. The excess of this water flows away to the hot-well
+through the pipe <i>W</i>.</p>
+
+<p>Catch-pins, <i>x</i>, are provided, to prevent the beam descending
+too far should the engine make too long a stroke; two
+wooden springs, <i>y y</i>, receive the blow. The great beam is
+carried on sectors, <i>z z</i>, to diminish losses by friction.</p>
+
+<div class="figright"><a name="Fig22" id="Fig22"></a>
+<img src="images/illo094.png" alt="Newcomen Engine Boiler" width="230" height="350" />
+<p class="caption"><span class="smcap">Fig. 22.</span>&mdash;Boiler of Newcomen&#8217;s<br />Engine, 1768.</p></div>
+
+<p>The boilers of Newcomen&#8217;s earlier engines were made of
+copper where in contact with the products of combustion,
+and their upper parts were of lead. Subsequently, sheet-iron
+was substituted. The steam-space in the boiler was
+made of 8 or 10 times the capacity of the cylinder of the
+engine. Even in Smeaton&#8217;s time, a chimney-damper was
+not used, and the supply of steam was consequently very
+variable. In the earlier engines, the
+cylinder was placed on the boiler;
+afterward, they were placed separately,
+and supported on a foundation
+of masonry. The injection or
+&#8220;jack-head&#8221; cistern was placed from
+12 to 30 feet above the engine, the
+velocity due the greater altitude
+being found to give the most perfect
+distribution of the water and the
+promptest condensation.</p>
+
+<p>Smeaton covered the lower side
+of his steam-pistons with wooden
+plank about 2<span class="enum">1</span>&#8725;<span class="denom">4</span> inches thick, in order
+that it should absorb and waste less
+heat than when the iron was directly
+exposed to the steam. Mr. Beighton was the first to use the
+water of condensation for feeding the boiler, taking it directly
+from the eduction-pipe, or the &#8220;hot-well.&#8221; Where
+only a sufficient amount of pure water could be obtained for<span class='pagenum'><a name="Page_68" id="Page_68">[68]</a></span>
+feeding the boiler, and the injection-water was &#8220;hard,&#8221; Mr.
+Smeaton applied a heater, immersed in the hot-well, through
+which the feed passed, absorbing heat from the water of
+condensation <i>en route</i> to the boiler. Farey first proposed
+the use of the &#8220;coil-heater&#8221;&mdash;a pipe, or &#8220;worm,&#8221; which,
+forming a part of the feed-pipe, was set in the hot-well.</p>
+
+<p>As early as 1743, the metal used for the cylinders was cast-iron.
+The earlier engines had been fitted with brass cylinders.
+Desaguliers recommended the iron cylinders, as being
+smoother, thinner, and as having less capacity for heat than
+those of brass.</p>
+
+<p>In a very few years after the invention of Newcomen&#8217;s
+engine it had been introduced into nearly all large mines in
+Great Britain; and many new mines, which could not have
+been worked at all previously, were opened, when it was
+found that the new machine could be relied upon to raise
+the large quantities of water to be handled. The first engine
+in Scotland was erected in 1720 at Elphinstone, in
+Stirlingshire. One was put up in Hungary in 1723.</p>
+
+<p>The first mine-engine, erected in 1712 at Griff, was 22
+inches in diameter, and the second and third engines were
+of similar size. That erected at Ansthorpe was 23 inches
+in diameter of cylinder, and it was a long time before much
+larger engines were constructed. Smeaton and others
+finally made them as large as 6 feet in diameter.</p>
+
+<p>In calculating the lifting-power of his engines, Newcomen&#8217;s
+method was &#8220;to square the diameter of the cylinder
+in inches, and, cutting off the last figure, he called it
+&#8216;long hundredweights;&#8217; then writing a cipher on the right
+hand, he called the number on that side &#8216;odd pounds;&#8217; this
+he reckoned tolerably exact at a mean, or rather when the
+barometer was above 30 inches, and the air heavy.&#8221; In
+allowing for frictional and other losses, he deducted from
+one-fourth to one-third. Desaguliers found the rule quite
+exact. The usual mean pressure resisting the motion of
+the piston averaged, in the best engines, about 8 pounds per<span class='pagenum'><a name="Page_69" id="Page_69">[69]</a></span>
+square inch of its area. The speed of the piston was from
+150 to 175 feet per minute. The temperature of the hot-well
+was from 145&deg; to 175&deg; Fahr.</p>
+
+<p>Smeaton made a number of test-trials of Newcomen
+engines to determine their &#8220;duty&#8221;&mdash;i. e., to ascertain the
+expenditure of fuel required to raise a definite quantity of
+water to a stated height. He found an engine 10 inches in
+diameter of cylinder, and of 3 feet stroke, could do work
+equal to raising 2,919,017 pounds of water one foot high,
+with a bushel of coals weighing 84 pounds.</p>
+
+<p>One of Smeaton&#8217;s larger engines, erected at Long Benton,
+was 52 inches in diameter of cylinder and of 7 feet
+stroke of piston, and made 12 strokes per minute. Its load
+was equal to 7<span class="enum">1</span>&#8725;<span class="denom">2</span> pounds per square inch of piston-area, and
+its effective capacity about 40 horse-power. Its duty was
+9<span class="enum">1</span>&#8725;<span class="denom">2</span> millions of pounds raised one foot high per bushel of
+coals. Its boiler evaporated 7.88 pounds of water per
+pound of fuel consumed. It had 35 square feet of grate-surface
+and 142 square feet of heating-surface beneath the
+boilers, and 317 square feet in the flues&mdash;a total of 459
+square feet. The moving parts of this engine weighed
+8<span class="enum">1</span>&#8725;<span class="denom">2</span> tons.</p>
+
+<p>Smeaton erected one of these engines at the Chasewater
+mine, in Cornwall, in 1775, which was of very considerable
+size. It was 6 feet in diameter of steam-cylinder, and had
+a maximum stroke of piston of 9<span class="enum">1</span>&#8725;<span class="denom">2</span> feet. It usually worked
+9 feet. The pumps were in three lifts of about 100 feet
+each, and were 16<span class="enum">3</span>&#8725;<span class="denom">4</span> inches in diameter. Nine strokes were
+made per minute. This engine replaced two others, of 64
+and of 62 inches diameter of cylinder respectively, and both
+of 6 feet stroke. One engine at the lower lift supplied the
+second, which was set above it. The lower one had pumps
+18<span class="enum">1</span>&#8725;<span class="denom">2</span> inches in diameter, and raised the water 144 feet; the
+upper engine raised the water 156 feet, by pumps 17<span class="enum">1</span>&#8725;<span class="denom">2</span> inches
+in diameter. The later engine replacing them exerted 76<span class="enum">1</span>&#8725;<span class="denom">2</span>
+horse-power. There were three boilers, each 15 feet in<span class='pagenum'><a name="Page_70" id="Page_70">[70]</a></span>
+diameter, and having each 23 square feet of grate-surface.
+The chimney was 22 feet high. The great beam, or &#8220;lever,&#8221;
+of this engine was built up of 20 beams of fir in two sets,
+placed side by side, and ten deep, strongly bolted together.
+It was over 6 feet deep at the middle and 5 feet at the
+ends, and was 2 feet thick. The &#8220;main centres,&#8221; or journals,
+on which it vibrated were 8<span class="enum">1</span>&#8725;<span class="denom">2</span> inches in diameter and
+8<span class="enum">1</span>&#8725;<span class="denom">2</span> inches long. The cylinder weighed 6<span class="enum">1</span>&#8725;<span class="denom">2</span> tons, and was
+paid for at the rate of 28 shillings per hundredweight.</p>
+
+<p>By the end of the eighteenth century, therefore, the engine
+of Newcomen, perfected by the ingenuity of Potter
+and of Beighton, and by the systematic study and experimental
+research of Smeaton, had become a well-established
+form of steam-engine, and its application to raising water
+had become general. The coal-mines of Coventry and of
+Newcastle had adopted this method of drainage; and the tin
+and the copper mines of Cornwall had been deepened, using,
+for drainage, engines of the largest size.</p>
+
+<p>Some engines had been set up in and about London, the
+scene of Worcester&#8217;s struggles and disappointments, where
+they were used to supply water to large houses. Others
+were in use in other large cities of England, where water-works
+had been erected.</p>
+
+<p>Some engines had also been erected to drive mills indirectly
+by raising water to turn water-wheels. This is said
+by Farey to have been first practised in 1752, at a mill near
+Bristol, and became common during the next quarter of a
+century. Many engines had been built in England and
+sent across the channel, to be applied to the drainage of
+mines on the Continent. Belidor<a name="FNanchor_32_32" id="FNanchor_32_32"></a><a href="#Footnote_32_32" class="fnanchor">[32]</a>
+stated that the manufacture
+of these &#8220;fire-engines&#8221; was exclusively confined to
+England; and this remained true many years after his time.
+When used for the drainage of mines, the engine usually
+worked the ordinary lift or bucket pump; when employed<span class='pagenum'><a name="Page_71" id="Page_71">[71]</a></span>
+for water-supply to cities, the force or plunger pump was
+often employed, the engine being placed below the level of
+the reservoir. Dr. Rees states that this engine was in common
+use among the collieries of England as early as 1725.</p>
+
+<p>The Edmonstone colliery was licensed, in 1725, to erect
+an engine, not to exceed 28 inches diameter of cylinder and
+9 feet stroke of piston, paying a royalty of &pound;80 per annum
+for eight years. This engine was built in Scotland, by
+workmen sent from England, and cost about &pound;1,200. Its
+&#8220;great cost&#8221; is attributed to an extensive use of brass.
+The workmen were paid their expenses and 15<i>s.</i> per week
+as wages. The builders were John and Abraham Potter,
+of Durham. An engine built in 1775, having a steam-cylinder
+48 inches in diameter and of 7 feet stroke, cost about
+&pound;2,000.</p>
+
+<p>Smeaton found 57 engines at work near Newcastle in
+1767, ranging in size from 28 to 75 inches in diameter of
+cylinder, and of, collectively, about 1,200 horse-power. Fifteen
+of these engines gave an average of 98 square inches
+of piston to the horse-power, and the average duty was
+5,590,000 pounds raised 1 foot high by 1 bushel (84 pounds)
+of coal. The highest duty noted was 7.44 millions; the
+lowest was 3.22 millions. The most efficient engine had a
+steam-cylinder 42 inches in diameter; the load was equivalent
+to 9<span class="enum">1</span>&#8725;<span class="denom">4</span> pounds per square inch of piston-area, and the
+horse-power developed was calculated to be 16.7.</p>
+
+<p>Price, writing in 1778, says, in the Appendix to his
+&#8220;Mineralogia Cornubiensis:&#8221; &#8220;Mr. Newcomen&#8217;s invention
+of the fire-engine enabled us to sink our mines to twice the
+depth we could formerly do by any other machinery. Since
+this invention was completed, most other attempts at its
+improvement have been very unsuccessful; but the vast
+consumption of fuel in these engines is an immense drawback
+on the profit of our mines, for every fire-engine of
+magnitude consumes &pound;3,000 worth of coals per annum.
+This heavy tax amounts almost to a prohibition.&#8221;<span class='pagenum'><a name="Page_72" id="Page_72">[72]</a></span></p>
+
+<p>Smeaton was given the description, in 1773, of a <i>stone</i>
+boiler, which was used with one of these engines at a copper
+mine at Camborne, in Cornwall. It contained three copper
+flues 22 inches in diameter. The gases were passed through
+these flues successively, finally passing off to the chimney.
+This boiler was cemented with hydraulic mortar. It was
+20 feet long, 9 feet wide, and 8<span class="enum">1</span>&#8725;<span class="denom">2</span> feet deep. It was heated
+by the waste heat from the roasting-furnaces. This was
+one of the earliest flue-boilers ever made.</p>
+
+<p>In 1780, Smeaton had a list of 18 large engines working
+in Cornwall. The larger number of them were built
+by Jonathan Hornblower and John Nancarron. At this
+time, the largest and best-known pumping-engine for water-works
+was at York Buildings, in Villiers Street, Strand,
+London. It had been in operation since 1752, and was
+erected beside one of Savery&#8217;s engines, built in 1710. It
+had a steam-cylinder 45 inches in diameter, and a stroke
+of piston of 8 feet, making 7<span class="enum">1</span>&#8725;<span class="denom">2</span> strokes per minute, and developing
+35<span class="enum">1</span>&#8725;<span class="denom">2</span> horse-power. Its boiler was dome-shaped,
+of copper, and contained a large central fire-box and a
+spiral flue leading outward to the chimney. Another
+somewhat larger machine was built and placed beside this
+engine, some time previous to 1775. Its cylinder was 49
+inches in diameter, and its stroke 9 feet. It raised water
+102 feet. This engine was altered and improved by Smeaton
+in 1777, and continued in use until 1813.</p>
+
+<p>Smeaton, as early as 1765, designed a <i>portable</i> engine,<a name="FNanchor_33_33" id="FNanchor_33_33"></a><a
+href="#Footnote_33_33" class="fnanchor">[33]</a>
+in which he supported the machinery on a wooden frame
+mounted on short legs and strongly put together, so that
+the whole machine could be transported and set at work
+wherever convenient.</p>
+
+<div class="figcenter"><a name="Fig23" id="Fig23"></a>
+<img src="images/illo100.png" alt="Smeaton's Portable-Engine Boiler" width="350" height="344" />
+<p class="caption"><span class="smcap">Fig. 23.</span>&mdash;Smeaton&#8217;s Portable-Engine<br />Boiler, 1765.</p></div>
+
+<p>In place of the beam, a large pulley was used, over
+which a chain was carried, connecting the piston with the
+pump-rod, and the motion was similar to that given by the<span class='pagenum'><a name="Page_73" id="Page_73">[73]</a></span>
+discarded beam. The wheel was supported on A-frames,
+resembling somewhat the &#8220;gallows-frames&#8221; still used with
+the beam-engines of American river-boats. The sills carrying
+the two A&#8217;s supported the cylinder. The injection-cistern
+was supported above the great pulley-wheel. The
+valve-gearing and the injection-pump were worked by a
+smaller wheel, mounted on the same axis with the larger
+one. The boiler was placed apart from the engine, with
+which it was connected by a steam-pipe, in which was
+placed the &#8220;regulator,&#8221; or throttle-valve. The boiler (<a href="#Fig23">Fig.
+23</a>) &#8220;was shaped like a large tea-kettle,&#8221; and contained a
+fire-box, <i>B</i>, or internal furnace, of which the sides were
+made of cast-iron. The fire-door, <i>C</i>, was placed on one
+side and opposite the flue, <i>D</i>, through which the products of
+combustion were led to the chimney, <i>E</i>; a short, large pipe,
+<i>F</i>, leading downward from the furnace to the outside of the
+boiler, was the ash-pit. The shell of the boiler, <i>A</i>, was made
+of iron plate one-quarter of an inch thick. The steam-cylinder<span class='pagenum'><a name="Page_74" id="Page_74">[74]</a></span>
+of the engine was 18 inches in diameter, the stroke of
+piston 6 feet, the great wheel 6<span class="enum">1</span>&#8725;<span class="denom">2</span> feet in diameter, and the
+A-frames 9 feet high. The boiler was made 6 feet, the furnace
+34 inches, and the grate 18 inches in diameter. The
+piston was intended to make 10 strokes per minute, and the
+engine to develop 4<span class="enum">1</span>&#8725;<span class="denom">8</span> horse-power.</p>
+
+<p>In 1773, Smeaton prepared plans for a pumping-engine
+to be set up at Cronstadt, the port of St. Petersburg, to
+empty the great dry dock constructed by Peter the Great
+and Catherine, his successor. This great dock was begun
+in 1719. It was large enough to dock ten of the ships of
+that time, and had previously been imperfectly drained by
+two great windmills 100 feet high. So imperfectly did they
+do their work, that a <i>year</i> was required to empty the dock,
+and it could therefore only be used once in each summer.
+The engine was built at the Carron Iron Works, in England.
+It had a cylinder 66 inches in diameter, and a stroke
+of piston of 8<span class="enum">1</span>&#8725;<span class="denom">2</span> feet. The lift varied from 33 feet when
+the dock was full to 53 feet when it was cleared of water.
+The load on the engine averaged about 8<span class="enum">1</span>&#8725;<span class="denom">3</span> pounds per
+square inch of piston-area. There were three boilers, each
+10 feet in diameter, and 16 feet 4 inches high to the apex of
+its hemispherical dome. They contained internal fire-boxes
+with grates of 20 feet area, and were surrounded by flues
+helically traversing the masonry setting. The engine was
+started in 1777, and worked very successfully.</p>
+
+<p>The lowlands of Holland were, before the time of Smeaton,
+drained by means of windmills. The uncertainty and
+inefficiency of this method precluded its application to anything
+like the extent to which steam-power has since been
+utilized. In 1440, there were 150 inland lakes, or &#8220;<i>meers</i>,&#8221;
+in that country, of which nearly 100, having an extent of
+over 200,000 acres, have since been drained. The &#8220;Haarlemmer
+Meer&#8221; alone covers nearly 50,000 acres, and forms
+the basin of a drainage-area of between 200,000 and 300,000
+acres, receiving a rainfall of 54,000,000 tons, which<span class='pagenum'><a name="Page_75" id="Page_75">[75]</a></span>
+must be raised 16 feet in discharging it. The beds of these
+lakes are from 10 to 20 feet lower than the water-level in
+the adjacent canals. In 1840, 12,000 windmills were still
+employed in this work. In the following year, William II.,
+at the suggestion of a commission, decreed that only steam-engines
+should be employed to do this immense work. Up
+to this time the average consumption of fuel for the pumping-engines
+in use is said to have been 20 pounds per hour
+per horse-power.</p>
+
+<p>The first engine used was erected in 1777 and 1778, on
+the Newcomen plan, to assist the 34 windmills employed to
+drain a lake near Rotterdam. This lake covered 7,000
+acres, and its bed was 12 feet below the surface of the
+river Meuse, which passes it, and empties into the sea in the
+immediate neighborhood. The iron parts of the engine
+were built in England, and the machine was put together in
+Holland. The steam-cylinder was 52 inches in diameter,
+and the stroke of piston 9 feet. The boiler was 18 feet in
+diameter, and contained a double flue. The main beam was
+27 feet long. The pumps were 6 in number, 3 cylindrical
+and 3 having a square cross-section; 3 were of 6 feet and
+3 of 2<span class="enum">1</span>&#8725;<span class="denom">2</span> feet stroke. Two pumps only were worked at high-tide,
+and the others were added one at a time, as the tide
+fell, until, at low-tide, all 6 were at work.</p>
+
+<p>The size of this engine, and the magnitude of its
+work, seem insignificant when compared with the machinery
+installed 60 years later to drain the Haarlemmer Meer, and
+with the work done by the last. These engines are 12 feet
+in diameter of cylinder and 10 feet stroke of piston, and
+work&mdash;they are 3 in number&mdash;the one 11 pumps of 63 inches
+diameter and 10 feet stroke, the others 8 pumps of
+73 inches diameter and of the same length of stroke. The
+modern engines do a &#8220;duty&#8221; of 75,000,000 to 87,000,000
+with 94 pounds of coal, consuming 2<span class="enum">1</span>&#8725;<span class="denom">4</span> pounds of coal per
+hour and per horse-power.</p>
+
+<p>The first steam-engine applied to working the blowing-machinery<span class='pagenum'><a name="Page_76" id="Page_76">[76]</a></span>
+of a blast-furnace was erected at the Carron
+Iron-Works, in Scotland, near Falkirk, in 1765, and proved
+very unsatisfactory. Smeaton subsequently, in 1769 or
+1770, introduced better machinery into these works and
+improved the old engine, and this use of the steam-engine
+soon became usual. This engine did its work indirectly,
+furnishing water, by pumping, to drive the water-wheels
+which worked the blowing-cylinders. Its steam-cylinder
+was 6 feet in diameter, and the pump-cylinder 52 inches.
+The stroke was 9 feet.</p>
+
+<p>A direct-acting engine, used as a blowing-engine, was not
+constructed until about 1784, at which time a single-acting
+blowing-cylinder, or air-pump, was placed at the &#8220;out-board&#8221;
+end of the beam, where the pump-rod had been
+attached. The piston of the air-cylinder was loaded with
+the weights needed to force it down, expelling the air, and
+the engine did its work in raising the loaded piston, the air-cylinder
+filling as the piston rose. A large &#8220;accumulator&#8221;
+was used to equalize the pressure of the expelled air. This
+consisted of another air-cylinder, having a loaded piston
+which was left free to rise and fall. At each expulsion of
+air by the blowing-engine this cylinder was filled, the loaded
+piston rising to the top. While the piston of the former
+was returning, and the air-cylinder was taking in its charge
+of air, the accumulator would gradually discharge the
+stored air, the piston slowly falling under its load. This
+piston was called the &#8220;floating piston,&#8221; or &#8220;fly-piston,&#8221; and
+its action was, in effect, precisely that of the upper portion
+of the common blacksmith&#8217;s bellows.</p>
+
+<p>Dr. Robison, the author of &#8220;Mechanical Philosophy,&#8221;
+one of the very few works even now existing deserving such
+a title, describes one of these engines<a name="FNanchor_34_34" id="FNanchor_34_34"></a><a href="#Footnote_34_34" class="fnanchor">[34]</a>
+as working in Scotland
+in 1790. It had a steam-cylinder 40 or 44 inches in
+diameter, a blowing-cylinder 60 inches in diameter, and the<span class='pagenum'><a name="Page_77" id="Page_77">[77]</a></span>
+stroke of piston was 6 feet. The air-pressure was 2.77
+pounds per square inch as a maximum in the blowing-cylinder;
+and the floating piston in the regulating-cylinder was
+loaded with 2.63 pounds per square inch. Making 15 or
+18 strokes per minute, this engine delivered about 1,600
+cubic feet of air, or 120<span class="enum">1</span>&#8725;<span class="denom">2</span> pounds in weight, per minute,
+and developed 20 horse-power.</p>
+
+<p>At about the same date a change was made in the blowing-cylinder.
+The air entered at the bottom, as before, but
+was forced out at the top, the piston being fitted with
+valves, as in the common lifting-pump, and the engine thus
+being arranged to do the work of expulsion during the
+down-stroke of the steam-piston.</p>
+
+<p>Four years later, the regulating-cylinder, or accumulator,
+was given up, and the now familiar &#8220;water-regulator&#8221;
+was substituted for it. This consists of a tank, usually of
+sheet-iron, set open-end downward in a large vessel containing
+water. The lower edge of the inner tank is supported
+on piers a few inches above the bottom of the large
+one. The pipe carrying air from the blowing-engine passes
+above this water-regulator, and a branch-pipe is led down
+into the inner tank. As the air-pressure varies, the level of
+the water within the inverted tank changes, rising as pressure
+falls at the slowing of the motion of the piston, and
+falling as the pressure rises again while the piston is moving
+with an accelerated velocity. The regulator, thus receiving
+surplus air to be delivered when needed, greatly assists in
+regulating the pressure. The larger the regulator, the more
+perfectly uniform the pressure. The water-level outside
+the inner tank is usually five or six feet higher than within
+it. This apparatus was found much more satisfactory than
+the previously-used regulator, and, with its introduction, the
+establishment of the steam-engine as a blowing-engine for
+iron-works and at blast-furnaces may be considered as having
+been fully established.</p>
+
+<p>Thus, by the end of the third quarter of the eighteenth<span class='pagenum'><a name="Page_78" id="Page_78">[78]</a></span>
+century, the steam-engine had become generally introduced,
+and had been applied to nearly all of the purposes for which
+a single-acting engine could be used. The path which had
+been opened by Worcester had been fairly laid out by Savery
+and his contemporaries, and the builders of the Newcomen
+engine, with such improvements as they had been able to effect,
+had followed it as far as they were able. The real and
+practical introduction of the steam-engine is as fairly attributable
+to Smeaton as to any one of the inventors whose
+names are more generally known in connection with it. As
+a mechanic, he was unrivaled; as an engineer, he was head
+and shoulders above any constructor of his time engaged in
+general practice. There were very few important public
+works built in Great Britain at that time in relation to
+which he was not consulted; and he was often visited by
+foreign engineers, who desired his advice with regard to
+works in progress on the Continent.</p>
+
+<hr class="l05" />
+<div class="colleft">
+<div class="footnote"><p class="left"><a name="Footnote_30_30" id="Footnote_30_30"></a><a href="#FNanchor_30_30"><span class="label">[30]</span></a>
+It has been denied that a patent was issued, but there is no doubt
+that Savery claimed and received an interest in the new engine.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_31_31" id="Footnote_31_31"></a><a href="#FNanchor_31_31"><span class="label">[31]</span></a> A fac-simile of a sketch in Galloway&#8217;s &#8220;On the Steam-Engine,&#8221; etc.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_32_32" id="Footnote_32_32"></a><a href="#FNanchor_32_32"><span class="label">[32]</span></a>
+&#8220;Architecture Hydraulique,&#8221; 1734.</p></div>
+</div>
+
+<div class="footnote"><p class="left"><a name="Footnote_33_33" id="Footnote_33_33"></a><a href="#FNanchor_33_33"><span class="label">[33]</span></a>
+Smeaton&#8217;s &#8220;Reports,&#8221; vol. i., p. 223.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_34_34" id="Footnote_34_34"></a><a href="#FNanchor_34_34"><span class="label">[34]</span></a>
+&#8220;Encyclop&aelig;dia Britannica,&#8221; 1st edition.</p></div>
+
+<hr class="l05" />
+<p>&nbsp;</p>
+
+<div class="figcenter"><img src="images/illo105.png" alt="Ornament" width="250" height="284" /></div>
+<hr class="c40" />
+
+<p class='pagenum'><a name="Page_79" id="Page_79">[79]</a></p>
+<h2><a name="CHAPTER_III" id="CHAPTER_III"></a>CHAPTER III.</h2>
+
+<h3><i>THE DEVELOPMENT OF THE MODERN STEAM-ENGINE.
+JAMES WATT AND HIS CONTEMPORARIES.</i></h3>
+
+<hr class="c05" />
+
+<div class="blockquot"><p>The world is now entering upon the Mechanical Epoch. There is nothing
+in the future more sure than the great triumphs which that epoch is to
+achieve. It has already advanced to some glorious conquests. What miracles
+of invention now crowd upon us! Look abroad, and contemplate the
+infinite achievements of the steam-power.</p>
+
+<p>And yet we have only begun&mdash;we are but on the threshold of this
+epoch.... What is it but the setting of the great distinctive seal upon the
+nineteenth century?&mdash;an advertisement of the fact that society has risen to
+occupy a higher platform than ever before?&mdash;a proclamation from the high
+places, announcing honor, honor immortal, to the workmen who fill this
+world with beauty, comfort, and power&mdash;honor to be forever embalmed in
+history, to be perpetuated in monuments, to be written in the hearts of this
+and succeeding generations!&mdash;<span class="smcap">Kennedy.</span></p></div>
+
+<hr class="c05" />
+<h4><span class="smcap">Section I.&mdash;James Watt and his Inventions.</span></h4>
+<hr class="c05" />
+
+<p>The success of the Newcomen engine naturally attracted
+the attention of mechanics, and of scientific men as well, to
+the possibility of making other applications of steam-power.</p>
+
+<p>The best men of the time gave much attention to the
+subject, but, until James Watt began the work that has
+made him famous, nothing more was done than to improve
+the proportions and slightly alter the details of the Newcomen
+and Calley engine, even by such skillful engineers as
+Brindley and Smeaton. Of the personal history of the
+earlier inventors and improvers of the steam-engine, very
+little is ascertained; but that of Watt has become well
+known.</p>
+
+<div class="figcenter"><a name="Port4" id="Port4"></a>
+<img src="images/illo107.png" alt="James Watt" width="350" height="427" />
+<p class="caption">James Watt.</p></div>
+
+<p><span class='pagenum'><a name="Page_80" id="Page_80">[80]</a></span>
+<span class="smcap"><a href="#Port4">James Watt</a></span> was of an humble lineage, and was born
+at Greenock, then a little Scotch fishing village, but now
+a considerable and a busy town, which annually launches
+upon the waters of the Clyde a fleet of steamships whose
+engines are probably, in the aggregate, far more powerful
+than were all the engines in the world at the date of Watt&#8217;s
+birth, January 19, 1736. His grandfather, Thomas Watt,
+of Crawfordsdyke, near Greenock, was a well-known mathematician
+about the year 1700, and was for many years a
+schoolmaster at that place. His father was a prominent
+citizen of Greenock, and was at various times chief magistrate
+and treasurer of the town. James Watt was a bright
+boy, but exceedingly delicate in health, and quite unable to
+attend school regularly, or to apply himself closely to either
+study or play. His early education was given by his parents,
+who were respectable and intelligent people, and the
+tools borrowed from his father&#8217;s carpenter-bench served at<span class='pagenum'><a name="Page_81" id="Page_81">[81]</a></span>
+once to amuse him and to give him a dexterity and familiarity
+with their use that must undoubtedly have been of
+inestimable value to him in after-life.</p>
+
+<p>M. Arago, the eminent French philosopher, who wrote
+one of the earliest and most interesting biographies of
+Watt, relates anecdotes of him which, if correct, illustrate
+well his thoughtfulness and his intelligence, as well as the
+mechanical bent of the boy&#8217;s mind. He is said, at the age
+of six years, to have occupied himself during leisure hours
+with the solution of geometrical problems; and Arago discovers,
+in a story in which he is described as experimenting
+with the tea-kettle,<a name="FNanchor_35_35" id="FNanchor_35_35"></a><a href="#Footnote_35_35" class="fnanchor">[35]</a>
+his earliest investigations of the nature
+and properties of steam.</p>
+
+<p>When finally sent to the village school, his ill health
+prevented his making rapid progress; and it was only
+when thirteen or fourteen years of age that he began to
+show that he was capable of taking the lead in his class, and
+to exhibit his ability in the study, particularly, of mathematics.
+His spare time was principally spent in sketching
+with his pencil, in carving, and in working at the bench,
+both in wood and metal. He made many ingenious pieces
+of mechanism, and some beautiful models. His favorite
+work seemed to be the repairing of nautical instruments.
+Among other pieces of apparatus made by the boy was
+a very fine barrel-organ. In boyhood, as in after-life, he
+was a diligent reader, and seemed to find something to interest
+him in every book that came into his hands.</p>
+
+<p>At the age of eighteen, Watt was sent to Glasgow, there
+to reside with his mother&#8217;s relatives, and to learn the trade
+of a mathematical-instrument maker. The mechanic with
+whom he was placed was soon found too indolent, or was
+otherwise incapable of giving much aid in the project, and
+Dr. Dick, of the University of Glasgow, with whom Watt
+became acquainted, advised him to go to London. Accordingly,<span class='pagenum'><a name="Page_82" id="Page_82">[82]</a></span>
+he set out in June, 1755, for the metropolis, where, on
+his arrival, he arranged with Mr. John Morgan, in Cornhill,
+to work a year at his chosen business, receiving as compensation
+20 guineas. At the end of the year he was compelled,
+by serious ill-health, to return home.</p>
+
+<p>Having become restored to health, he went again to
+Glasgow in 1756, with the intention of pursuing his calling
+there. But, not being the son of a burgess, and not having
+served his apprenticeship in the town, he was forbidden by
+the guilds, or trades-unions, to open a shop in Glasgow.
+Dr. Dick came to his aid, and employed him to repair some
+apparatus which had been bequeathed to the college. He
+was finally allowed the use of three rooms in the University
+building, its authorities not being under the municipal rule.
+He remained here until 1760, when, the trades no longer
+objecting, he took a shop in the city; and in 1761 moved
+again, into a shop on the north side of the Trongate, where
+he earned a scanty living without molestation, and still
+kept up his connection with the college. He did some work
+as a civil engineer in the neighborhood of Glasgow, but
+soon gave up all other employment, and devoted himself
+entirely to mechanics.</p>
+
+<p>He spent much of his leisure time&mdash;of which he had, at
+first, more than was desirable&mdash;in making philosophical experiments
+and in the manufacture of musical instruments,
+in making himself familiar with the sciences, and in devising
+improvements in the construction of organs. In order
+to pursue his researches more satisfactorily, he studied German
+and Italian, and read Smith&#8217;s &#8220;Harmonics,&#8221; that he
+might become familiar with the principles of construction of
+musical instruments. His reading was still very desultory;
+but the introduction of the Newcomen engine in the neighborhood
+of Glasgow, and the presence of a model in the
+college collections, which was placed in his hands, in 1763,
+for repair, led him to study the history of the steam-engine,
+and to conduct for himself an experimental research<span class='pagenum'><a name="Page_83" id="Page_83">[83]</a></span>
+into the properties of steam, with a set of improvised apparatus.</p>
+
+<p>Dr. Robison, then a student of the University, who
+found Watt&#8217;s shop a pleasant place in which to spend his
+leisure, and whose tastes affiliated so strongly with those of
+Watt that they became friends immediately upon making
+acquaintance, called the attention of the instrument-maker
+to the steam-engine as early as 1759, and suggested that it
+might be applied to the propulsion of carriages. Watt was
+at once interested, and went to work on a little model, having
+tin steam-cylinders and pistons connected to the driving-wheels
+by an intermediate system of gearing. The scheme
+was afterwards given up, and was not revived by Watt for a
+quarter of a century.</p>
+
+<p>Watt studied chemistry, and was assisted by the advice
+and instruction of Dr. Black, who was then making the researches
+which resulted in the discovery of &#8220;latent heat.&#8221;
+His proposal to repair the model Newcomen engine in the
+college collections led to his study of Desaguliers&#8217;s treatise,
+and of the works of Switzer and others. He thus learned
+what had been done by Savery and by Newcomen, and
+by those who had improved the engine of the latter.</p>
+
+<p>In his own experiments he used, at first, apothecaries&#8217;
+phials and hollow canes for steam reservoirs and pipes, and
+later a Papin&#8217;s digester and a common syringe. The latter
+combination made a non-condensing engine, in which he
+used steam at a pressure of 15 pounds per square inch.
+The valve was worked by hand, and Watt saw that an
+automatic valve-gear only was needed to make a working
+machine. This experiment, however, led to no practical result.
+He finally took hold of the Newcomen model, which
+had been obtained from London, where it had been sent
+for repairs, and, putting it in good working order, commenced
+experiments with that.</p>
+
+<div class="figcenter"><a name="Fig24" id="Fig24"></a>
+<img src="images/illo111.png" alt="Newcomen Model" width="252" height="350" />
+<p class="caption"><span class="smcap">Fig. 24.</span>&mdash;The Newcomen Model.</p></div>
+
+<p>The Newcomen model, as it happened, had a boiler
+which, although made to a scale from engines in actual use,<span class='pagenum'><a name="Page_84" id="Page_84">[84]</a></span>
+was quite incapable of furnishing steam enough to work the
+engine. It was about nine inches in diameter; the steam-cylinder
+was two inches in diameter, and of six inches stroke
+of piston, arranged as in <a href="#Fig24">Fig. 24</a>, which is a picture of the
+model as it now appears. It is retained among the most
+carefully-preserved treasures of the University of Glasgow.</p>
+
+<p>Watt made a new boiler for the experimental investigation
+on which he was about to enter, and arranged it in such
+a manner that he could measure the quantity of water evaporated
+and of steam used at every stroke of the engine.</p>
+
+<p>He soon discovered that it required but a very small
+quantity of steam to heat a very large quantity of water,
+and immediately attempted to determine with precision the
+relative weights of steam and water in the steam-cylinder
+when condensation took place at the down-stroke of the<span class='pagenum'><a name="Page_85" id="Page_85">[85]</a></span>
+engine, and thus independently proved the existence of that
+&#8220;latent heat,&#8221; the discovery of which constitutes, also, one
+of the greatest of Dr. Black&#8217;s claims to distinction. Watt
+at once went to Dr. Black and related the remarkable fact
+which he had thus detected, and was, in turn, taught by
+Black the character of the phenomenon as it had been explained
+to his classes by the latter some little time previously.
+Watt found that, at the boiling-point, his steam, condensing,
+was capable of heating six times its weight of
+water such as was used for producing condensation.</p>
+
+<p>Perceiving that steam, weight for weight even, was a
+vastly greater absorbent and reservoir of heat than water,
+Watt saw plainly the importance of taking greater care to
+economize it than had previously been customary. He first
+attempted to economize in the boiler, and made boilers with
+wooden &#8220;shells,&#8221; in order to prevent losses by conduction
+and radiation, and used a larger number of flues to secure
+more complete absorption of the heat from the furnace-gases.
+He also covered his steam-pipes with non-conducting
+materials, and took every precaution that his ingenuity
+could devise to secure complete utilization of the heat of
+combustion. He soon found, however, that he was not
+working at the most important point, and that the great
+source of loss was to be found in defects which he noted in
+the action of the steam in the cylinder. He soon concluded
+that the sources of loss of heat in the Newcomen engine&mdash;which
+would be greatly exaggerated in a small model&mdash;were:</p>
+
+<p>First, the dissipation of heat by the cylinder itself,
+which was of brass, and was both a good conductor and a
+good radiator.</p>
+
+<p>Secondly, the loss of heat consequent upon the necessity
+of cooling down the cylinder at every stroke, in producing
+the vacuum.</p>
+
+<p>Thirdly, the loss of power due to the pressure of vapor
+beneath the piston, which was a consequence of the imperfect
+method of condensation.<span class='pagenum'><a name="Page_86" id="Page_86">[86]</a></span></p>
+
+<p>He first made a cylinder of non-conducting material&mdash;wood
+soaked in oil and then baked&mdash;and obtained a decided
+advantage in economy of steam. He then conducted
+a series of very accurate experiments upon the temperature
+and pressure of steam at such points on the scale as he could
+readily reach, and, constructing a curve with his results,
+the abscesses representing temperatures and the pressures
+being represented by the ordinates, he ran the curve backward
+until he had obtained closely-approximate measures of
+temperatures less than 212&deg;, and pressures less than atmospheric.
+He thus found that, with the amount of injection-water
+used in the Newcomen engine, bringing the temperature
+of the interior, as he found, down to from 140&deg; to 175&deg;
+Fahr., a very considerable back-pressure would be met with.</p>
+
+<p>Continuing his examination still further, he measured
+the amount of steam used at each stroke, and, comparing it
+with the quantity that would just fill the cylinder, he found
+that at least <i>three-fourths was wasted</i>. The quantity of
+cold water necessary to produce the condensation of a given
+weight of steam was next determined; and he found that
+one pound of steam contained enough heat to raise about
+six pounds of cold water, as used for condensation, from the
+temperature of 52&deg; to the boiling-point; and, going still
+further, he found that he was compelled to use, at each
+stroke of the Newcomen engine, <i>four times as much injection-water
+as should suffice to condense a cylinder full of
+steam</i>. This confirmed his previous conclusion that three-fourths
+of the heat supplied to the engine was wasted.</p>
+
+<p>Watt had now, therefore, determined by his own researches,
+as he himself enumerates them,<a name="FNanchor_36_36" id="FNanchor_36_36"></a><a href="#Footnote_36_36" class="fnanchor">[36]</a> the following
+facts:</p>
+
+<p>&#8220;1. The capacities for heat of iron, copper, and of
+some sorts of wood, as compared with water.</p>
+
+<p>&#8220;2. The bulk of steam compared with that of water.</p>
+
+<p><span class='pagenum'><a name="Page_87" id="Page_87">[87]</a></span>&#8220;3. The quantity of water evaporated in a certain
+boiler by a pound of coal.</p>
+
+<p>&#8220;4. The elasticities of steam at various temperatures
+greater than that of boiling water, and an approximation to
+the law which it follows at other temperatures.</p>
+
+<p>&#8220;5. How much water in the form of steam was required
+every stroke by a small Newcomen engine, with a
+wooden cylinder 6 inches in diameter and 12 inches stroke.</p>
+
+<p>&#8220;6. The quantity of cold water required in every stroke
+to condense the steam in that cylinder, so as to give it a
+working-power of about 7 pounds on the square inch.&#8221;</p>
+
+<p>After these well-devised and truly scientific investigations,
+Watt was enabled to enter upon his work of improving
+the steam-engine with an intelligent understanding of
+its existing defects, and with a knowledge of their cause.
+Watt soon saw that, in order to reduce the losses in the
+working of the steam in the steam-cylinder, it would be
+necessary to find some means, as he said, to keep the cylinder
+&#8220;always as hot as the steam that entered it,&#8221; notwithstanding
+the great fluctuations of temperature and pressure
+of the steam during the up and the down strokes. He has
+told us how, finally, the happy thought occurred to him
+which relieved him of all difficulty, and led to the series of
+modifications which at last gave to the world the modern
+type of steam-engine.</p>
+
+<p>He says:<a name="FNanchor_37_37" id="FNanchor_37_37"></a><a href="#Footnote_37_37" class="fnanchor">[37]</a>
+&#8220;I had gone to take a walk on a fine Sabbath
+afternoon. I had entered the Green by the gate at
+the foot of Charlotte street, and had passed the old washing-house.
+I was thinking upon the engine at the time,
+and had gone as far as the herd&#8217;s house, when the idea came
+into my mind that, as steam was an elastic body, it would
+rush into a vacuum, and, if a communication were made between
+the cylinder and an exhausted vessel, it would rush
+into it, and might be there condensed without cooling the<span class='pagenum'><a name="Page_88" id="Page_88">[88]</a></span>
+cylinder. I then saw that I must get rid of the condensed
+steam and injection-water if I used a jet, as in Newcomen&#8217;s
+engine. Two ways of doing this occurred to me: First,
+the water might be run off by a descending pipe, if an offlet
+could be got at the depth of 35 or 36 feet, and any air
+might be extracted by a small pump. The second was, to
+make the pump large enough to extract both water and air.&#8221;
+&#8220;I had not walked farther than the Golf-house, when the
+whole thing was arranged in my mind.&#8221;</p>
+
+<p>Referring to this invention, Watt said to Prof. Jardine:<a name="FNanchor_38_38" id="FNanchor_38_38"></a><a href="#Footnote_38_38"
+class="fnanchor">[38]</a>
+&#8220;When analyzed, the invention would not appear so great
+as it seemed to be. In the state in which I found the
+steam-engine, it was no great effort of mind to observe that
+the quantity of fuel necessary to make it work would
+forever prevent its extensive utility. The next step in
+my progress was equally easy&mdash;to inquire what was the
+cause of the great consumption of fuel. This, too, was
+readily suggested, viz., the waste of fuel which was necessary
+to bring the whole cylinder, piston, and adjacent parts
+from the coldness of water to the heat of steam, no fewer
+than from 15 to 20 times in a minute.&#8221; It was by pursuing
+this train of thought that he was led to devise the separate
+condenser.</p>
+
+<div class="figcenter"><a name="Fig25" id="Fig25"></a>
+<img src="images/illo116.png" alt="Watt's Experiment" width="311" height="350" />
+<p class="caption"><span class="smcap">Fig. 25.</span>&mdash;Watt&#8217;s Experiment.</p></div>
+
+<p>On Monday morning Watt proceeded to make an experimental
+test of his new invention, using for his steam-cylinder
+and piston a large brass surgeon&#8217;s-syringe, 1<span class="enum">3</span>&#8725;<span class="denom">4</span>-inch
+diameter and 10 inches long. At each end was a pipe leading
+steam from the boiler, and fitted with a cock to act as
+a steam-valve. A pipe led also from the top of the cylinder
+to the condenser, the syringe being inverted and the
+piston-rod hanging downward for convenience. The condenser
+was made of two pipes of thin tin plate, 10 or 12
+inches long, and about one-sixth of an inch in diameter,
+standing vertically, and having a connection at the top<span class='pagenum'><a name="Page_89" id="Page_89">[89]</a></span>
+with a horizontal pipe of larger size, and fitted with a
+&#8220;snifting-valve.&#8221; Another vertical pipe, about an inch in
+diameter, was connected to the condenser, and was fitted
+with a piston, with a view to using it as an &#8220;air-pump.&#8221;
+The whole was set in a cistern of cold water. The piston-rod
+of the little steam-cylinder was drilled from end to end
+to permit the water to be removed from the cylinder. This
+little model (<a href="#Fig25">Fig. 25</a>) worked very satisfactorily, and the
+perfection of the vacuum was such that the machine lifted
+a weight of 18 pounds hung upon the piston-rod, as in the
+sketch. A larger model was immediately afterward constructed,
+and the result of its test confirmed fully the anticipations
+which had been awakened by the first experiment.</p>
+
+<p>Having taken this first step and made such a radical
+improvement, the success of this invention was no sooner
+determined than others followed in rapid succession, as consequences
+of the exigencies arising from the first change in
+the old Newcomen engine. But in the working out of the
+forms and proportions of the details of the new engine,
+even Watt&#8217;s powerful mind, stored as it was with happily-combined
+scientific and practical information, was occupied<span class='pagenum'><a name="Page_90" id="Page_90">[90]</a></span>
+for years. In attaching the separate condenser, he first
+attempted surface-condensation; but this not succeeding
+well, he substituted the jet. Some provision became at
+once necessary for preventing the filling of the condenser
+with water.</p>
+
+<p>Watt at first intended adopting the expedient which had
+worked satisfactorily with the less effective condensation of
+Newcomen&#8217;s engine&mdash;i. e., leading a pipe from the condenser
+to a depth greater than the height of a column of water
+which could be counterbalanced by the pressure of the
+atmosphere; but he subsequently employed the air-pump,
+which relieves the condenser not only of the water, but of
+the air which also usually collects in considerable volume in
+the condenser, and vitiates the vacuum. He next substituted
+oil and tallow for water in the lubrication of the piston and
+keeping it steam-tight, in order to avoid the cooling of the
+cylinder incident to the use of the latter. Another cause
+of refrigeration of the cylinder, and consequent waste of
+power in its operation, was seen to be the entrance of the
+atmosphere, which followed the piston down the cylinder at
+each stroke, cooling its interior by its contact. This the
+inventor concluded to prevent by covering the top of the
+cylinder, allowing the piston-rod to play through a &#8220;stuffing-box&#8221;&mdash;which
+device had long been known to mechanics.</p>
+
+<p>He accordingly not only covered the top, but surrounded
+the whole cylinder with an external casing, or
+&#8220;steam-jacket,&#8221; and allowed the steam from the boiler to
+pass around the steam-cylinder and to press upon the upper
+surface of the piston, where its pressure was variable at
+pleasure, and therefore more manageable than that of the
+atmosphere. It also, besides keeping the cylinder hot,
+could do comparatively little harm should it leak by the
+piston, as it could be condensed, and thus readily disposed of.</p>
+
+<p>When he had concluded to build the larger experimental
+engine, Watt determined to give his whole time and attention
+to the work, and hired a room in an old deserted<span class='pagenum'><a name="Page_91" id="Page_91">[91]</a></span>
+pottery near the Broomielaw. Here he worked with a
+mechanic&mdash;John Gardiner, whom he had taken into his employ&mdash;uninterruptedly
+for many weeks. Meantime, through
+his friend Dr. Black, probably, he had made the acquaintance
+of Dr. Roebuck, a wealthy physician, who had, with
+other Scotch capitalists, just founded the celebrated Carron
+Iron-Works, and had opened a correspondence with him, in
+which he kept that gentleman informed of the progress of
+his work on the new engine.</p>
+
+<p>This engine had a steam-cylinder, Watt tells us, of &#8220;five
+or six&#8221; inches diameter, and of two feet stroke. It was of
+copper, smooth-hammered, but not bored out, and &#8220;not
+very true.&#8221; This was encased in another cylinder of wood.
+In August, 1765, he tried the small engine, and wrote Dr.
+Roebuck that he had had &#8220;good success,&#8221; although the
+machine was very imperfect. &#8220;On turning the exhausting-cock,
+the piston, when not loaded, ascended as quick as
+the blow of a hammer, and as quick when loaded with 18
+pounds (being 7 pounds on the inch) as it would have done
+if it had had an injection as usual.&#8221; He then tells his
+correspondent that he was about to make the larger model.
+In October, 1765, he finished the latter. The engine, when
+ready for trial, was still very imperfect. It nevertheless did
+good work for so rude a machine.</p>
+
+<p>Watt was now reduced to poverty, and, after borrowing
+considerable sums from friends, he was finally compelled to
+give up his scheme for the time, and to seek employment in
+order to provide for his family. During an interval of about
+two years he supported himself by surveying, and by the
+work of exploring coal-fields in the neighborhood of Glasgow
+for the magistrates of the city. He did not, however,
+entirely give up his invention.</p>
+
+<p>In 1767, Dr. Roebuck assumed Watt&#8217;s liabilities to the
+amount of &pound;1,000, and agreed to provide capital for the prosecution
+of his experiments and to introduce his invention;
+and, on the other hand, Watt agreed to surrender to Dr.<span class='pagenum'><a name="Page_92" id="Page_92">[92]</a></span>
+Roebuck two-thirds of the patent. Another engine was
+next built, having a steam-cylinder seven or eight inches
+in diameter, which was finished in 1768. This worked sufficiently
+well to induce the partners to ask for a patent, and
+the specifications and drawings were completed and presented
+in 1769.</p>
+
+<p>Watt also built and set up several Newcomen engines,
+partly, perhaps, to make himself thus thoroughly familiar
+with the practical details of engine-building. Meantime,
+also, he prepared the plans for, and finally had built, a moderately
+large engine of his own new type. Its steam-cylinder
+was 18 inches in diameter, and the stroke of piston was
+5 feet. This engine was built at Kinneil, and was finished
+in September, 1769. It was not all satisfactory in either
+its construction or its operation. The condenser was a
+surface-condenser composed of pipes somewhat like that
+used in his first little model, and did not prove to be satisfactorily
+tight. The steam-piston leaked seriously, and repeated
+trials only served to make more evident its imperfections.
+He was assisted in this time of need by both Dr. Black and
+Dr. Roebuck; but he felt strongly the risks which he ran
+of involving his friends in serious losses, and became very
+despondent. Writing to Dr. Black, he says: &#8220;Of all
+things in life, there is nothing more foolish than inventing;&#8221;
+and probably the majority of inventors have been led to the
+same opinion by their own experiences.</p>
+
+<p>&#8220;Misfortunes never come singly;&#8221; and Watt was borne
+down by the greatest of all misfortunes&mdash;the loss of a faithful
+and affectionate wife&mdash;while still unable to see a successful
+issue of his schemes. Only less disheartening than
+this was the loss of fortune of his steadfast friend, Dr. Roebuck,
+and the consequent loss of his aid. It was at about
+this time, in the year 1769, that negotiations were commenced
+which resulted in the transfer of the capitalized interest
+in Watt&#8217;s engine to the wealthy manufacturer whose
+name, coupled with that of Watt, afterward became known<span class='pagenum'><a name="Page_93" id="Page_93">[93]</a></span>
+throughout the civilized world, as the steam-engine in its
+new form was pushed into use by his energy and business
+tact.</p>
+
+<p>Watt met Mr. Boulton, who next became his partner, in
+1768, on his journey to London to procure his patent, and
+the latter had then examined Watt&#8217;s designs, and, at once
+perceiving their value, proposed to purchase an interest.
+Watt was then unable to reply definitely to Boulton&#8217;s proposition,
+pending his business arrangements with Dr. Roebuck;
+but, with Roebuck&#8217;s consent, afterwards proposed
+that Boulton should take a one-third interest with himself
+and partner, paying Roebuck therefor one-half of all expenses
+previously incurred, and whatever he should choose
+to add to compensate &#8220;for the risk he had run.&#8221; Subsequently,
+Dr. Roebuck proposed to transfer to Boulton and
+to Dr. Small, who was desirous of taking interest with
+Boulton, one-half of his proprietorship in Watt&#8217;s inventions,
+on receiving &#8220;a sum not less than one thousand pounds,&#8221;
+which should, after the experiments on the engine were
+completed, be deemed &#8220;just and reasonable.&#8221; Twelve
+months were allowed for the adjustment of the account.
+This proposal was accepted in November, 1769.</p>
+
+<div class="figcenter"><a name="Port5" id="Port5"></a>
+<img src="images/illo121.png" alt="Matthew Boulton" width="350" height="428" />
+<p class="caption">Matthew Boulton.</p></div>
+
+<p><span class="smcap"><a href="#Port5">Matthew Boulton</a></span>, who now became a partner with
+James Watt, was the son of a Birmingham silver stamper
+and piecer, and succeeded to his father&#8217;s business, building
+up a great establishment, which, as well as its proprietor,
+was well known in Watt&#8217;s time. Watt, writing to Dr.
+Roebuck before the final arrangement had been made,
+urged him to close with Boulton for &#8220;the following considerations:</p>
+
+<p>&#8220;1st. From Mr. Boulton&#8217;s own character as an ingenious,
+honest, and rich man. 2dly. From the difficulty and
+expense there would be of procuring accurate and honest
+workmen and providing them with proper utensils, and
+getting a proper overseer or overseers. If, to avoid this
+inconvenience, you were to contract for the work to be done<span class='pagenum'><a name="Page_94" id="Page_94">[94]</a></span>
+by a master-workman, you must give up a great share of
+the profit. 3dly. The success of the engine is far from
+being verified. If Mr. Boulton takes his chance of success
+from the account I shall write Dr. Small, and pays you
+any adequate share of the money laid out, it lessens your risk,
+and in a greater proportion than I think it will lessen your
+profits. 4thly. The assistance of Mr. Boulton&#8217;s and Dr.
+Small&#8217;s ingenuity (if the latter engage in it) in improving
+and perfecting the machine may be very considerable, and
+may enable us to get the better of the difficulties that might
+otherwise damn it. Lastly, consider my uncertain health,
+my irresolute and inactive disposition, my inability to bargain
+and struggle for my own with mankind: all which
+disqualify me for any great undertaking. On our side,
+consider the first outlay and interest, the patent, the present
+engine, about &pound;200 (though there would not be much loss<span class='pagenum'><a name="Page_95" id="Page_95">[95]</a></span>
+in making it into a common engine), two years of my time,
+and the expense of models.&#8221;</p>
+
+<p>Watt&#8217;s estimate of the value of Boulton&#8217;s ingenuity and
+talent was well-founded. Boulton had shown himself a good
+scholar, and had acquired considerable knowledge of the
+languages and of the sciences, particularly of mathematics,
+after leaving the school from which he graduated into the
+shop when still a boy. In the shop he soon introduced
+a number of valuable improvements, and he was always
+on the lookout for improvements made by others, with a
+view to their introduction in his business. He was a man
+of the modern style, and never permitted competitors to
+excel him in any respect, without the strongest efforts to
+retain his leading position. He always aimed to earn a
+reputation for good work, as well as to make money. His
+father&#8217;s workshop was at Birmingham; but Boulton, after a
+time, found that his rapidly-increasing business would compel
+him to find room for the erection of a more extensive
+establishment, and he secured land at Soho, two miles distant
+from Birmingham, and there erected his new manufactory,
+about 1762.</p>
+
+<p>The business was, at first, the manufacture of ornamental
+metal-ware, such as metal buttons, buckles, watch-chains,
+and light filigree and inlaid work. The manufacture of
+gold and silver plated-ware was soon added, and this branch
+of business gradually developed into a very extensive manufacture
+of works of art. Boulton copied fine work wherever
+he could find it, and often borrowed vases, statuettes,
+and bronzes of all kinds from the nobility of England, and
+even from the queen, from which to make copies. The
+manufacture of inexpensive clocks, such as are now well
+known throughout the world as an article of American trade,
+was begun by Boulton. He made some fine astronomical
+and valuable ornamental clocks, which were better appreciated
+on the Continent than in England. The business of
+the Soho manufactory in a few years became so extensive,<span class='pagenum'><a name="Page_96" id="Page_96">[96]</a></span>
+that its goods were known to every civilized nation, and its
+growth, under the management of the enterprising, conscientious,
+and ingenious Boulton, more than kept pace with
+the accumulation of capital; and the proprietor found himself,
+by his very prosperity, often driven to the most careful
+manipulation of his assets, and to making free use of
+his credit.</p>
+
+<p>Boulton had a remarkable talent for making valuable
+acquaintances, and for making the most of advantages accruing
+thereby. In 1758 he made the acquaintance of
+Benjamin Franklin, who then visited Soho; and in 1766
+these distinguished men, who were then unaware of the
+existence of James Watt, were corresponding, and, in their
+letters, discussing the applicability of steam-power to various
+useful purposes. Between the two a new steam-engine was
+designed, and a model was constructed by Boulton, which
+was sent to Franklin and exhibited by him in London.</p>
+
+<p>Dr. Darwin seems to have had something to do with
+this scheme, and the enthusiasm awakened by the promise
+of success given by this model may have been the origin of
+the now celebrated prophetic rhymes so often quoted from
+the works of that eccentric physician and poet. Franklin
+contributed, as his share in the plan, an idea of so arranging
+the grate as to prevent the production of smoke. He says:
+&#8220;All that is necessary is to make the smoke of fresh coals
+pass descending through those that are already ignited.&#8221;
+His idea has been, by more recent schemers, repeatedly
+brought forward as new. Nothing resulted from these experiments
+of Boulton, Franklin, and Darwin, and the plan
+of Watt soon superseded all less well-developed plans.</p>
+
+<p>In 1767, Watt visited Soho and carefully inspected
+Boulton&#8217;s establishment. He was very favorably impressed
+by the admirable arrangement of the workshops and the
+completeness of their outfit, as well as by the perfection of
+the organization and administration of the business. In
+the following year he again visited Soho, and this time met<span class='pagenum'><a name="Page_97" id="Page_97">[97]</a></span>
+Boulton, who had been absent at the previous visit. The
+two great mechanics were mutually gratified by the meeting,
+and each at once acquired for the other the greatest
+respect and esteem. They discussed Watt&#8217;s plans, and
+Boulton then definitely decided not to continue his own
+experiments, although he had actually commenced the construction
+of a pumping-engine. With Dr. Small, who was
+also at Soho, Watt discussed the possibility of applying his
+engine to the propulsion of carriages, and to other purposes.
+On his return home, Watt continued his desultory labors
+on his engines, as already described; and the final completion
+of the arrangement with Boulton, which immediately
+followed the failure of Dr. Roebuck, took place some time
+later.</p>
+
+<p>Before Watt could leave Scotland to join his partner at
+Soho, it was necessary that he should finish the work which
+he had in hand, including the surveys of the Caledonian
+canal, and other smaller works, which he had had in progress
+some months. He reached Birmingham in the spring of
+1774, and was at once domiciled at Soho, where he set at
+work upon the partly-made engines which had been sent
+from Scotland some time previously. They had laid, unused
+and exposed to the weather, at Kinneil three years, and
+were not in as good order as might have been desired. The
+<i>block-tin</i> steam-cylinder was probably in good condition,
+but the iron parts were, as Watt said, &#8220;perishing,&#8221; while
+he had been engaged in his civil engineering work. At
+leisure moments, during this period, Watt had not entirely
+neglected his plans for the utilization of steam. He had
+given much thought, and had expended some time, in experiments
+upon the plan of using it in a rotary or &#8220;wheel&#8221;
+engine. He did not succeed in contriving any plan which
+seemed to promise success.</p>
+
+<p>It was in November, 1774, that Watt finally announced
+to his old partner, Dr. Roebuck, the successful trial of the
+Kinneil engine. He did not write with the usual enthusiasm<span class='pagenum'><a name="Page_98" id="Page_98">[98]</a></span>
+and extravagance of the inventor, for his frequent disappointments
+and prolonged suspense had very thoroughly
+extinguished his vivacity. He simply wrote: &#8220;The fire-engine
+I have invented is now going, and answers much
+better than any other that has yet been made; and I expect
+that the invention will be very beneficial to me.&#8221;</p>
+
+<div class="figcenter"><a name="Fig26" id="Fig26"></a>
+<img src="images/illo125.png" alt="Watt's Engine" width="350" height="531" />
+<p class="caption"><span class="smcap">Fig. 26.</span>&mdash;Watt&#8217;s Engine, 1774.</p></div>
+
+<p>The change of the &#8220;atmospheric engine&#8221; of Newcomen
+into the modern steam-engine was now completed in its
+essential details. The first engine which was erected at
+Kinneil, near Boroughstoness, had a steam-cylinder 18
+inches in diameter. It is seen in the accompanying sketch.</p>
+
+<p>In <a href="#Fig26">Fig. 26</a>, the steam passes from the boiler through the
+pipe <i>d</i> and the valve <i>c</i> to the cylinder-casing or steam-jacket,
+<i>Y Y</i>, and above the piston, <i>b</i>, which it follows in its<span class='pagenum'><a name="Page_99" id="Page_99">[99]</a></span>
+descent in the cylinder, <i>a</i>, the valve <i>f</i> being at this time
+open, to allow the exhaust into the condenser, <i>h</i>.</p>
+
+<p>The piston now being at the lower end of the cylinder,
+and the pump-rods at the opposite end of the beam, <i>y</i>, being
+thus raised and the pumps filled with water, the valves <i>c</i>
+and <i>f</i> close, while <i>e</i> opens, allowing the steam which remains
+above the piston to flow beneath it, until, the pressures
+becoming equal above and below, the weight of the pump-rods
+overbalancing that of the piston, the latter is rapidly
+drawn to the top of the cylinder, while the steam is displaced
+above, passing to the under-side of the piston.</p>
+
+<p>The valve <i>e</i> is next closed, and <i>c</i> and <i>f</i> are again opened;
+the down-stroke is repeated. The water and air entering
+the condenser are removed at each stroke by the air-pump,
+<i>i</i>, which communicates with the condenser by the passage <i>s</i>.
+The pump <i>q</i> supplies condensing-water, and the pump <i>A</i>
+takes away a part of the water of condensation, which is
+thrown by the air-pump into the &#8220;hot-well,&#8221; <i>k</i>, and from
+it the feed-pump supplies the boiler. The valves are
+moved by valve-gear very similar to Beighton&#8217;s and Smeaton&#8217;s,
+by the pins, <i>m m</i>, in the &#8220;plug-frame&#8221; or &#8220;tappet-rod,&#8221;
+<i>n n</i>.</p>
+
+<p>The engine is mounted upon a substantial foundation,
+<i>B B</i>. <i>F</i> is an opening out of which, before starting the
+engine, the air is driven from the cylinder and condenser.</p>
+
+<p>The inventions covered by the patent of 1769 were described
+as follows:</p>
+
+<p>&#8220;My method of lessening the consumption of steam,
+and consequently fuel, in fire-engines, consists in the following
+principles:</p>
+
+<p>&#8220;1st. That the vessel in which the powers of steam are
+to be employed to work the engine&mdash;which is called &#8216;the
+cylinder&#8217; in common fire-engines, and which I call &#8216;the
+steam-vessel&#8217;&mdash;must, during the whole time that the engine
+is at work, be kept as hot as the steam which enters it; first,
+by inclosing it in a case of wood, or any other materials that<span class='pagenum'><a name="Page_100" id="Page_100">[100]</a></span>
+transmit heat slowly; secondly, by surrounding it with
+steam or other heated bodies; and thirdly, by suffering
+neither water nor other substances colder than the steam to
+enter or touch it during that time.</p>
+
+<p>&#8220;2dly. In engines that are to be worked, wholly or partially,
+by condensation of steam, the steam is to be condensed
+in vessels distinct from the steam-vessel or cylinder,
+though occasionally communicating with them. These vessels
+I call condensers; and while the engines are working,
+these <i>condensers</i> ought at least to be kept as cold as the air
+in the neighborhood of the engines, by application of water
+or other cold bodies.</p>
+
+<p>&#8220;3dly. Whatever air or other elastic vapor is not condensed
+by the cold of the condenser, and may impede the
+working of the engine, is to be drawn out of the steam-vessels
+or condensers by means of pumps, wrought by the engines
+themselves, or otherwise.</p>
+
+<p>&#8220;4thly. I intend in many cases to employ the expansive
+force of steam to press on the pistons, or whatever may be
+used instead of them, in the same manner as the pressure
+of the atmosphere is now employed in common fire-engines.
+In cases where cold water cannot be had in plenty, the
+engines may be wrought by this force of steam only, by
+discharging the steam into the open air after it has done its
+office.</p>
+
+<p>&#8220;5thly. Where motions round an axis are required, I
+make the steam-vessels in form of hollow rings or circular
+channels, with proper inlets and outlets for the steam,
+mounted on horizontal axles like the wheels of a water-mill.
+Within them are placed a number of valves that suffer any
+body to go round the channel in one direction only. In
+these steam-vessels are placed weights, so fitted to them as
+to fill up a part or portion of their channels, yet rendered
+capable of moving freely in them by the means hereinafter
+mentioned or specified. When the steam is admitted in
+these engines between these weights and the valves, it acts<span class='pagenum'><a name="Page_101" id="Page_101">[101]</a></span>
+equally on both, so as to raise the weight on one side of the
+wheel, and, by the reaction of the valves successively, to
+give a circular motion to the wheel, the valves opening in
+the direction in which the weights are pressed, but not in
+the contrary. As the vessel moves round, it is supplied
+with steam from the boiler, and that which has performed
+its office may either be discharged by means of condensers,
+or into the open air.</p>
+
+<p>&#8220;6thly. I intend in some cases to apply a degree of
+cold not capable of reducing the steam to water, but of contracting
+it considerably, so that the engines shall be worked
+by the alternate expansion and contraction of the steam.</p>
+
+<p>&#8220;Lastly, instead of using water to render the piston or
+other parts of the engine air or steam-tight, I employ oils,
+wax, resinous bodies, fat of animals, quicksilver, and other
+metals, in their fluid state.&#8221;</p>
+
+<p>In the construction and erection of his engines, Watt
+still had great difficulty in finding skillful workmen to make
+the parts with accuracy, to fit them with care, and to erect
+them properly when once finished. And the fact that both
+Newcomen and Watt met with such serious trouble, indicates
+that, even had the engine been designed earlier, it is
+quite unlikely that the world would have seen the steam-engine
+a success until this time, when mechanics were just
+acquiring the skill requisite for its construction. But, on
+the other hand, it is not at all improbable that, had the mechanics
+of an earlier period been as skillful and as well-educated
+in the manual niceties of their business, the steam-engine
+might have been much earlier brought into use.</p>
+
+<p>In the time of the Marquis of Worcester it would have
+probably been found impossible to obtain workmen to construct
+the steam-engine of Watt, had it been then invented.
+Indeed, Watt, upon one occasion, congratulated himself that
+one of his steam-cylinders only lacked <i>three-eighths</i> of an
+inch of being truly cylindrical.</p>
+
+<p>The history of the steam-engine is from this time a history<span class='pagenum'><a name="Page_102" id="Page_102">[102]</a></span>
+of the work of the firm of Boulton &amp; Watt. Newcomen
+engines continued to be built for years after Watt
+went to Soho, and by many builders. A host of inventors
+still worked on the most attractive of all mechanical combinations,
+seeking to effect further improvements. Some
+inventions were made by contemporaries of Watt, as will
+be seen hereafter, which were important as being the germs
+of later growths; but these were nearly all too far in advance
+of the time, and nearly every successful and important
+invention which marked the history of steam-power for
+many years originated in the fertile brain of James Watt.</p>
+
+<p>The defects of the Newcomen engine were so serious,
+that it was no sooner known that Boulton of Soho had
+become interested in a new machine for raising water by
+steam-power, than inquiries came to him from all sides,
+from mine-owners who were on the point of being drowned
+out, and from proprietors whose profits were absorbed by
+the expense of pumping, and who were glad to pay the &pound;5
+per horse-power per year finally settled upon as royalty.
+The London municipal water-works authorities were also
+ready to negotiate for pumping-engines for raising water to
+supply the metropolis. The firm was therefore at once
+driven to make preparations for a large business.</p>
+
+<p>The first and most important matter, however, was to
+secure an extension of the patent, which was soon to expire.
+If not renewed, the 15 years of study and toil, of poverty
+and anxiety, through which Watt had toiled, would
+prove profitless to the inventor, and the fruits of his genius
+would have become the unearned property of others. Watt
+saw, at one time, little hope of securing the necessary act of
+Parliament, and was greatly tempted to accept a position
+tendered him by the Russian Government, upon the solicitation
+of his old friend, Dr. Robison, then a Professor of
+Mathematics at the Naval School at Cronstadt. The salary
+was &pound;1,000&mdash;a princely income for a man in Watt&#8217;s circumstances,
+and a peculiar temptation to the needy mechanic.</p>
+
+<p><span class='pagenum'><a name="Page_103" id="Page_103">[103]</a></span>Watt, however, went to London, and, with the help of
+his own and of Boulton&#8217;s influential friends, succeeded in
+getting his bill through. His patent was extended 24
+years, and Boulton &amp; Watt set about the work of introducing
+their engines with the industry and enterprise which
+characterized their every act.</p>
+
+<p>In the new firm, Boulton took charge of the general
+business, and Watt superintended the design, construction,
+and erection of their engines. Boulton&#8217;s business capacity,
+with Watt&#8217;s wonderful mechanical ability&mdash;Boulton&#8217;s physical
+health, and his vigor and courage, offsetting Watt&#8217;s
+feeble health and depression of spirits&mdash;and, more than all,
+Boulton&#8217;s pecuniary resources, both in his own purse and in
+those of his friends, enabled the firm to conquer all difficulties,
+whether in finance, in litigation, or in engineering.</p>
+
+<p>It was only after the successful erection and operation
+of several engines that Boulton and Watt became legally
+partners. The understood terms were explicitly stated by
+Watt to include an assignment to Boulton of two-thirds
+the patent-right; Boulton paying all expenses, advancing
+stock in trade at an appraised valuation, on which it was to
+draw interest; Watt making all drawings and designs, and
+drawing one-third net profits.</p>
+
+<p>As soon as Watt was relieved of the uncertainties regarding
+his business connections, he married a second wife,
+who, as Arago says, by &#8220;her various talent, soundness of
+judgment, and strength of character,&#8221; made a worthy companion
+to the large-hearted and large-brained engineer.
+Thenceforward his cares were only such as every business-man
+expects to be compelled to sustain, and the next ten
+years were the most prolific in inventions of any period in
+Watt&#8217;s life.</p>
+
+<p>From 1775 to 1785 the partners acquired five patents,
+covering a large number of valuable improvements upon
+the steam-engine, and several independent inventions. The
+first of these patents covered the now familiar and universally-used<span class='pagenum'><a name="Page_104" id="Page_104">[104]</a></span>
+copying-press for letters, and a machine for drying
+cloth by passing it between copper rollers filled with
+steam of sufficiently high temperature to rapidly evaporate
+the moisture. This patent was issued February 14, 1780.</p>
+
+<div class="figcenter"><a name="Fig27" id="Fig27"></a>
+<img src="images/illo131.png" alt="Watt's Engine" width="400" height="488" />
+<p class="caption"><span class="smcap">Fig. 27.</span>&mdash;Watt&#8217;s Engine, 1781.</p></div>
+
+<p>In the following year, October 25, 1781, Watt patented
+five devices by which he obtained the rotary motion of the
+engine-shaft without the use of a crank. One of these was
+the arrangement shown in <a href="#Fig27">Fig. 27</a>, and known as the &#8220;sun-and-planet&#8221;<span class='pagenum'><a name="Page_105" id="Page_105">[105]</a></span>
+wheels. The crank-shaft carries a gear-wheel,
+which is engaged by another securely fixed upon the end of
+the connecting-rod. As the latter is compelled to revolve
+about the axis of the shaft by a tie which confines the connecting-rod
+end at a fixed distance from the shaft, the
+shaft-gear is compelled to revolve, and the shaft with it.
+Any desired velocity-ratio was secured by giving the two
+gears the necessary relative diameters. A fly-wheel was
+used to regulate the motion of the shaft.<a name="FNanchor_39_39"
+id="FNanchor_39_39"></a><a href="#Footnote_39_39" class="fnanchor">[39]</a> Boulton &amp; Watt
+used the sun-and-planet device on many engines, but finally
+adopted the crank, when the expiration of the patent held
+by Matthew Wasborough, and which had earlier date than
+Watt&#8217;s patent of 1781, permitted them. Watt had proposed
+the use of a crank, it is said, as early as 1771, but Wasborough
+anticipated him in securing the patent. Watt had made
+a model of an engine with a crank and fly-wheel, and he has
+stated that one of his workmen, who had seen the model,
+described it to Wasborough, thus enabling the latter to deprive
+Watt of his own property. The proceeding excited
+great indignation on the part of Watt; but no legal action
+was taken by Boulton &amp; Watt, as the overthrow of the
+patent was thought likely to do them injury by permitting
+its use by more active competitors and more ingenious men.</p>
+
+<p>The next patent issued to Watt was an exceedingly important
+one, and of especial interest in a history of the
+development of the economical application of steam. This
+patent included:</p>
+
+<p>1. The expansion of steam, and six methods of applying
+the principle and of equalizing the expansive power.</p>
+
+<p>2. The double-acting steam-engine, in which the steam
+acts on each side of the piston alternately, the opposite side
+being in communication with the condenser.</p>
+
+<p><span class='pagenum'><a name="Page_106" id="Page_106">[106]</a></span>3. The double or coupled steam-engine&mdash;two engines
+capable of working together, or independently, as may be
+desired.</p>
+
+<p>4. The use of a rack on the piston-rod, working into a
+sector on the end of the beam, thus securing a perfect rectilinear
+motion of the rod.</p>
+
+<p>5. A rotary engine, or &#8220;steam-wheel.&#8221;</p>
+
+<p>The efficiency to be secured by the expansion of steam
+had long been known to Watt, and he had conceived the
+idea of economizing some of that power, the waste of which
+was so plainly indicated by the violent rushing of the exhaust-steam
+into the condenser, as early as 1769. This was
+described in a letter to Dr. Small, of Birmingham, in May of
+that year. When experimenting at Kinneil, he had tried
+to determine the real value of the principle by trial on his
+small engine.</p>
+
+<p>Boulton had also recognized the importance of this improved
+method of working steam, and their earlier Soho
+engines were, as Watt said, made with cylinders &#8220;double
+the size wanted, and cut off the steam at half-stroke.&#8221; But,
+though &#8220;this was a great saving of steam, so long as the
+valves remained as at first,&#8221; the builders were so constantly
+annoyed by alterations of the valves by proprietors and
+their engineers, that they finally gave up that method of
+working, hoping ultimately to be able to resume it when
+workmen of greater intelligence and reliability could be
+found. The patent was issued July 17, 1782.</p>
+
+<p>Watt specified a cut-off at one-quarter stroke as usually
+best.</p>
+
+<p>Watt&#8217;s explanation of the method of economizing by
+expansive working, as given to Dr. Small,<a name="FNanchor_40_40" id="FNanchor_40_40"></a><a href="#Footnote_40_40" class="fnanchor">[40]</a> is worthy of reproduction.
+He says: &#8220;I mentioned to you a method of
+still doubling the effect of steam, and that tolerably easy,
+by using the power of steam rushing into a vacuum, at<span class='pagenum'><a name="Page_107" id="Page_107">[107]</a></span>
+present lost. This would do a little more than double the
+effect, but it would too much enlarge the vessels to use it
+all. It is peculiarly applicable to wheel-engines, and may
+supply the want of a condenser where force of steam is only
+used; for, open one of the steam-valves and admit steam,
+until one-fourth of the distance between it and the next
+valve is filled with steam, shut the valve, and the steam
+will continue to expand and to pass round the wheel with a
+diminishing power, ending in one-fourth its first exertion.
+The sum of this series you will find greater than one-half,
+though only one-fourth steam was used. The power will
+indeed be unequal, but this can be remedied by a fly, or in
+several other ways.&#8221;</p>
+
+<p>It will be noticed that Watt suggests, above, the now
+well-known non-condensing engine. He had already, as has
+been seen, described it in his patent of 1769, as also the
+rotary engine.</p>
+
+<div class="figcenter"><a name="Fig28" id="Fig28"></a>
+<img src="images/illo135.png" alt="Steam Expansion" width="233" height="400" />
+<p class="caption"><span class="smcap">Fig. 28.</span>&mdash;Expansion of Steam.</p></div>
+
+<p>Watt illustrates and explains his idea very neatly, by
+a sketch similar to that here given (<a href="#Fig28">Fig. 28</a>).</p>
+
+<p>Steam, entering the cylinder at <i>a</i>, is admitted until one-fourth
+the stroke has been made, when the steam-valve is
+closed, and the remainder of the stroke is performed without
+further addition of steam. The variation of steam-pressure
+is approximately inversely proportional to the variation
+of its volume. Thus, at half-stroke, the pressure becomes
+one-half that at which the steam was supplied to the
+cylinder. At the end of the stroke it has fallen to one-fourth
+the initial pressure. The pressure is always nearly
+equal to the product of the initial pressure and volume
+divided by the volume at the given instant. In symbols,</p>
+
+<table class="formula ind10" summary="Formula 107_1">
+
+<tr>
+<td rowspan="2"><i>P&#8242;&nbsp;=&nbsp;</i></td>
+<td class="padr1 padl1 bb"><i>PV</i></td>
+</tr>
+
+<tr>
+<td class="padr1 padl1"><i>V&#8242;</i></td>
+</tr>
+
+</table>
+
+<p>It is true that the condensation of steam doing work
+changes this law in a marked manner; but the condensation
+and re&euml;vaporation of steam, due to the transfer of heat to<span class='pagenum'><a name="Page_108" id="Page_108">[108]</a></span>
+and from the metal of the cylinder, tends to compensate
+the first variation by a reverse change of pressure with
+change of volume.</p>
+
+<p>The sketch shows this progressive variation of pressure
+as expansion proceeds. It is seen that the work done per
+unit of volume of steam as taken from the boiler is much
+greater than when working without expansion. The product
+of the mean pressure by the volume of the cylinder is
+less, but the quotient obtained by dividing this quantity by
+the volume or weight of steam taken from the boiler, is
+much greater with than without expansion. For the case
+assumed and illustrated, the work done during expansion is
+one and two-fifths times that done previous to cutting off
+the steam, and the work done per pound of steam is 2.4
+times that done without expansion.</p>
+
+<p>Were there no losses to be met with and to be exaggerated
+by the use of steam expansively, the gain would become<span class='pagenum'><a name="Page_109" id="Page_109">[109]</a></span>
+very great with moderate expansion, amounting to
+twice the work done when &#8220;following&#8221; full stroke, when
+the steam is cut off at one-seventh. The estimated gain is,
+however, never realized. Losses by friction, by conduction
+and radiation of heat, and by condensation and re&euml;vaporation
+in the cylinder&mdash;of which losses the latter are most
+serious&mdash;after passing a point which is variable, and which
+is determined by the special conditions in each case, augment
+with greater rapidity than the gain by expansion.</p>
+
+<p>In actual practice, it is rarely found, except where special
+precautions are taken to reduce these losses, that economy
+follows expansion to a greater number of volumes than
+about one-half the square root of the steam-pressure; i. e.,
+about twice for 15 or 20 pounds pressure, three times for
+about 30 pounds, and four and five times for 60 or 65 and
+for 100 to 125 pounds respectively. Watt very soon learned
+this general principle; but neither he, nor even many modern
+engineers, seem to have learned that too great expansion
+often gives greatly-reduced economy.</p>
+
+<p>The inequality of pressure due to expansion, to which
+he refers, was a source of much perplexity to Watt, as he
+was for a long time convinced that he must find some
+method of &#8220;equalizing&#8221; the consequent irregular effort of
+the steam upon the piston. The several methods of &#8220;equalizing
+the expansive power&#8221; which are referred to in the
+patent were attempts to secure this result. By one method,
+he shifted the centre as the beam vibrated, thus changing
+the lengths of the arms of that great lever, to compensate
+the change of moment consequent upon the change of pressure.
+He finally concluded that a fly-wheel, as first proposed
+by Fitzgerald, who advised its use on Papin&#8217;s engine, would
+be the best device on engines driving a crank, and trusted
+to the inertia of a balance-weight in his pumping-engines,
+or to the weight of the pump-rods, and permitted the piston
+to take its own speed so far as it was not thus controlled.</p>
+
+<p>The double-acting engine was a modification of the<span class='pagenum'><a name="Page_110" id="Page_110">[110]</a></span> single-acting
+engine, and was very soon determined upon after
+the successful working of the latter had become assured.</p>
+
+<p>Watt had covered in the top of his single-acting engine,
+to prevent cooling the interior of the cylinder by contact
+with the comparatively cold atmosphere. When this had
+been done, there was but a single step required to convert
+the machine into the double-acting engine. This alteration,
+by which the steam was permitted to act upon the upper
+and the lower sides of the piston alternately, had been proposed
+by Watt as early as 1767, and a drawing of the engine
+was laid before a committee of the House of Commons
+in 1774-&#8217;75. By this simple change Watt doubled the
+power of his engine. Although invented much earlier, the
+plan was not patented until he was, as he states, driven to
+take out the patent by the &#8220;plagiarists and pirates&#8221; who
+were always ready to profit by his ingenuity. This form
+of engine is now almost universally used. The single-acting
+pumping-engine remains in use in Cornwall, and in a few
+other localities, and now and then an engine is built for
+other purposes, in which steam acts only on one side of the
+piston; but these are rare exceptions to the general rule.</p>
+
+<p>The subject of his next invention was not less interesting.
+The double-cylinder or &#8220;compound&#8221; engine has now,
+after the lapse of nearly a century, become an important
+and usual type of engine. It is impossible to determine
+precisely to whom to award the credit of its first conception.
+Dr. Falk, in 1779, had proposed a double-acting engine,
+in which there were two single-acting cylinders, acting
+in opposite directions and alternately on opposite sides of a
+wheel, with which a rack on the piston-rod of each geared.</p>
+
+<p>Watt claimed that Hornblower, the patentee of the
+&#8220;compound engine,&#8221; was an infringer upon his patents; and,
+holding the patent on the separate condenser, he was able
+to prevent the engine of his competitor taking such form as
+to be successfully introduced. The Hornblower engine was
+soon given up.</p>
+
+<p><span class='pagenum'><a name="Page_111" id="Page_111">[111]</a></span>Watt stated that this form of engine had been invented
+by him as early as 1767, and that he had explained its peculiarities
+to Smeaton and others several years before Hornblower
+attempted to use it. He wrote to Boulton: &#8220;It is
+no less than our double-cylinder engine, worked upon our
+principle of expansion.&#8221; He never made use of the plan,
+however; and the principal object sought, apparently, in
+patenting this, as well as many other devices, was to secure
+himself against competition.</p>
+
+<p>The rack and sector patented at this time was soon superseded
+by the parallel-motion; and the last claim, the
+&#8220;steam-wheel&#8221; or rotary engine, although one was built of
+considerable size, was not introduced.</p>
+
+<p>After the patent of 1782 had been secured, Watt turned
+his attention, when not too hard-pressed by business, to
+other schemes, and to experimenting with still other modifications
+and applications of his engine. He had, as early
+as 1777, proposed to make a steam-hammer for Wilkinson&#8217;s
+forge; but he was too closely engaged with more important
+matters to take hold of the project with much earnestness
+until late in the year 1782, when, after some preliminary
+trials, he reported, December 13th: &#8220;We have tried our
+little tilting-forge hammer at Soho with success. The following
+are some of the particulars: Cylinder, 15 inches in
+diameter; 4 feet stroke; strokes per minute, 20. The
+hammer-head, 120 pounds weight, rises 8 inches, and strikes
+240 blows per minute. The machine goes quite regularly,
+and can be managed as easily as a water-mill. It requires
+a very small quantity of steam&mdash;not above half the contents
+of the cylinder per stroke. The power employed is not
+more than one-fourth of what would be required to raise
+the quantity of water which would enable a water-wheel to
+work the same hammer with the same velocity.&#8221;</p>
+
+<p>He immediately set about making a much heavier
+hammer, and on April 26, 1783, he wrote that he had
+done &#8220;a thing never done before&#8221;&mdash;making his hammer<span class='pagenum'><a name="Page_112" id="Page_112">[112]</a></span>
+strike 300 blows a minute. This hammer weighed 7<span class="enum">1</span>&#8725;<span class="denom">2</span> hundredweight,
+and had a drop of 2 feet. The steam-cylinder
+had a diameter of 42 inches and 6 feet stroke of piston, and
+was calculated to have sufficient power to drive four hammers
+weighing 7 hundredweight each. The engine made
+20 strokes per minute, the hammer giving 90 blows in the
+same time.</p>
+
+<p>This new application of steam-power proving successful,
+Watt next began to develop a series of minor inventions,
+which were finally secured by his patent of April 27, 1784,
+together with the steam tilt-hammer, and a steam-carriage,
+or &#8220;locomotive engine.&#8221;</p>
+
+<p>The contrivance previously used for guiding the head of
+the piston-rod&mdash;the sectors and chains, or rack&mdash;had never
+given satisfaction. The rudeness of design of the contrivance
+was only equalled by its insecurity. Watt therefore
+contrived a number of methods of accomplishing the purpose,
+the most beautiful and widely-known of which is the
+&#8220;parallel-motion,&#8221; although it has now been generally superseded
+by one of the other devices patented at the same
+time&mdash;the cross-head and guides. As originally proposed, a
+rod was attached to the head of the piston-rod, standing
+vertically when the latter was at quarter-stroke. The upper
+end of this rod was pivoted to the end of the beam, and the
+lower end to the extremity of a horizontal rod having a
+length equal to one-half the length of the beam. The other
+end of the horizontal rod was coupled to the frame of the
+engine. As the piston rose and fell, the upper and lower
+ends of the vertical rod were swayed in opposite directions,
+and to an equal extent, by the beam and the lower horizontal
+rod, the middle point at which the piston-rod was attached
+preserving its position in the vertical line. This
+form was objectionable, as the whole effort of the engine
+was transmitted through the parallel-motion rods. Another
+form is shown in the sketch given of the double-acting engine
+in <a href="#Fig31">Fig. 31</a>, which was free from this defect. The<span class='pagenum'><a name="Page_113" id="Page_113">[113]</a></span>
+head of the piston-rod, <i>g</i>, was guided by rods connecting it
+with the frame at <i>c</i>, and forming a &#8220;parallelogram,&#8221; <i>g d e b</i>,
+with the beam. Many varieties of &#8220;parallel-motion&#8221; have
+been devised since Watt&#8217;s invention was attached to his
+engines at Soho. They usually are more or less imperfect,
+guiding the piston-rod in a line only approximately straight.</p>
+
+<p>The cross-head and guides are now generally used, very
+much as described by Watt in this patent as his &#8220;second
+principle.&#8221; This device will be seen in the engravings
+given hereafter of more modern engines. The head of the
+piston-rod is fitted into a transverse bar, or cross-head,
+which carries properly-shaped pieces at its extremities, to
+which are bolted &#8220;gibs,&#8221; so made as to fit upon guides secured
+to the engine-frame. These guides are adjusted to
+precise parallelism with the centre line of the cylinder.
+The cross-head, sliding in or on these guides, moves in a
+perfectly straight line, and, compelling the piston-rod to
+move with it, the latter is even more perfectly guided than
+by a parallel-motion. This arrangement, where properly
+proportioned, is not necessarily subject to great friction,
+and is much more easily adjusted and kept in line than the
+parallel-motion when wear occurs or maladjustment takes
+place.</p>
+
+<p>By the same patent, Watt secured the now common
+&#8220;puppet-valve&#8221; with beveled seat, and the application of
+the steam-engine to driving rolling-mills and hammers for
+forges, and to &#8220;wheel-carriages for removing persons or
+goods, or other matters, from place to place.&#8221; For the latter
+purpose he proposes to use boilers &#8220;of wood, or of thin
+metal, strongly secured by hoops or otherwise,&#8221; and containing
+&#8220;internal fire-boxes.&#8221; He proposed to use a condenser
+cooled by currents of air.</p>
+
+<p>It would require too much space to follow Watt in all
+his schemes for the improvement and for the application of
+the steam-engine. A few of the more important and more
+ingenious only can be described. Many of the contracts of<span class='pagenum'><a name="Page_114" id="Page_114">[114]</a></span>
+Boulton &amp; Watt gave them, as compensation for their engines,
+a fraction&mdash;usually one-third&mdash;of the value of the
+fuel saved by the use of the Watt engine in place of the
+engine of Newcomen, the amount due being paid annually
+or semiannually, with an option of redemption on the part
+of the purchaser at ten years&#8217; purchase. This form of
+agreement compelled a careful determination, often, of the
+work done and fuel consumed by both the engine taken out
+and that put in its place. It was impossible to rely upon
+any determination by personal observation of the number
+of strokes made by the engine. Watt therefore made a
+&#8220;counter,&#8221; like that now familiar to every one as used on
+gas-meters. It consists of a train of wheels moving pointers
+on several dials, the first dial showing tens, the second
+hundreds, the third thousands, etc., strokes or revolutions.
+Motion was communicated to the train by means of a pendulum,
+the whole being mounted on the beam of the engine,
+where every vibration produced a swing of the pendulum.
+Eight dials were sometimes used, the counter being set and
+locked, and only opened once a year, when the time arrived
+for determining the work done during the preceding twelve-month.</p>
+
+<p>The application of his engine to purposes for which
+careful adjustment of speed was requisite, or where the load
+was subject to considerable variation, led to the use of a
+controlling-valve in the steam-pipe, called the &#8220;throttle-valve,&#8221;
+which was adjustable by hand, and permitted the
+supply of steam to the engine to be adjusted at any instant
+and altered to any desired extent. It is now given many
+forms, but it still is most usually made just as originally
+designed by Watt. It consists of a circular disk, which
+just closes up the steam-pipe when set directly across it, or
+of an elliptical disk, which closes the pipe when standing
+at an angle of somewhat less than 90&deg; with the line of
+the pipe. This disk is carried on a spindle extending
+through the pipe at one side, and carrying on its outer end<span class='pagenum'><a name="Page_115" id="Page_115">[115]</a></span>
+an arm by means of which it may be turned into any position.
+When placed with its face in line with the pipe, it
+offers very little resistance to the flow of steam to the engine.
+When set in the other position, it shuts off steam
+entirely and stops the engine. It is placed in such position
+at any time, that the speed of the engine is just that required
+at the time. In the engraving of the double-acting
+engine with fly-wheel (<a href="#Fig31">Fig. 31</a>), it is shown at <i>T</i>, as controlled
+by the governor.</p>
+
+<div class="figcenter"><a name="Fig29" id="Fig29"></a>
+<img src="images/illo142.png" alt="Fly-Ball Governor" width="282" height="350" />
+<p class="caption"><span class="smcap">Fig. 29.</span>&mdash;The Governor.</p></div>
+
+<p>The <a href="#Fig29">governor</a>, or &#8220;fly-ball governor,&#8221; as it is often
+distinctively called, was another of Watt&#8217;s minor but very
+essential inventions. Two heavy iron or brass balls, <i>B B&#8242;</i>,
+were suspended from pins, <i>C C&#8242;</i>, in a little cross-piece carried
+on the head of a vertical spindle, <i>A A&#8242;</i>, driven by the
+engine. The speed of the engine varying, that of the spindle
+changed correspondingly, and the faster the balls were swung
+the farther they separated. When the engine&#8217;s speed decreased,
+the period of revolution of the balls was increased,
+and they fell back toward the spindle. Whenever the velocity
+of the engine was uniform, the balls preserved their distance
+from the spindle and remained at the same height, their<span class='pagenum'><a name="Page_116" id="Page_116">[116]</a></span>
+altitude being determined by the relation existing between
+the force of gravity and centrifugal force in the temporary
+position of equilibrium. The distance from the point of suspension
+down to the level of the balls is always equal to 9.78
+inches divided by the square of the number of revolutions
+per second&mdash;i. e.,</p>
+
+<table class="ind10 formula" summary="Formula 116">
+
+<tr>
+<td rowspan="2"><i>h</i>&nbsp;=&nbsp;9.78&nbsp;</td>
+<td class="padr1 padl1 bb">1</td>
+<td rowspan="2">&nbsp;=&nbsp;0.248&nbsp;</td>
+<td class="padr1 padl1 bb">1</td>
+<td rowspan="2">meters.</td>
+</tr>
+
+<tr>
+<td class="padr1 padl1"><i>N<sup>2</sup></i></td>
+<td class="padr1 padl1"><i>N<sup>2</sup></i></td>
+</tr>
+
+</table>
+
+
+<p>The arms carrying the balls, or the balls themselves, are
+pinned to rods, <i>M M&#8242;</i>, which are connected to a piece, <i>N N&#8242;</i>,
+sliding loosely on the spindle. A score, <i>T</i>, cut in this piece
+engages a lever, <i>V</i>, and, as the balls rise and fall, a rod, <i>W</i>,
+is moved, closing and opening the throttle-valve, and thus
+adjusting the supply of steam in such a way as to preserve
+a nearly fixed speed of engine. The connection with the
+throttle-valve and with the cut-off valve-gear is seen not
+only in the engraving of the double-acting Watt engine, but
+also in those of the Greene and the Corliss engines. This
+contrivance had previously been used in regulating water-wheels
+and windmills. Watt&#8217;s invention consisted in its
+application to the regulation of the steam-engine.</p>
+
+<div class="figcenter"><a name="Fig30" id="Fig30"></a>
+<img src="images/illo144.png" alt="Steam and Water Gauge" width="350" height="300" />
+<p class="caption"><span class="smcap">Fig. 30.</span><br />Mercury Steam Gauge. Glass Water Gauge.</p></div>
+
+<p>Still another useful invention of Watt&#8217;s was his &#8220;mercury
+steam-gauge&#8221;&mdash;a barometer in which the height of the
+mercury was determined by the pressure of the steam instead
+of that of the atmosphere. This simple instrument
+consisted merely of a bent tube containing a portion of
+mercury. One leg, <i>B D</i>, of this U-tube was connected with
+the steam-pipe, or with the boiler by a small steam-pipe; the
+other end, <i>C</i>, was open to the atmosphere. The pressure of
+the steam on the mercury in <i>B D</i> caused it to rise in the
+other &#8220;leg&#8221; to a height exactly proportioned to the pressure,
+and causing very nearly two inches difference of level
+to the pound, or one inch to the pound actual rise in the
+outer leg. The rude sketch from Farey, here given (<a href="#Fig30">Fig.
+30</a>), indicates sufficiently well the form of this gauge. It is
+still considered by engineers the most reliable of all forms
+of steam-gauge. Unfortunately, it is not conveniently applicable<span class='pagenum'><a name="Page_117" id="Page_117">[117]</a></span>
+at high pressure. The scale, <i>A</i>, is marked with
+numbers indicating the pressure, which numbers are indicated
+by the head of a rod floating up with the mercury.</p>
+
+<p>A similar gauge was used to determine the degree of
+perfection of vacuum attained in the condenser, the mercury
+falling in the outer leg as the vacuum became more
+complete. A perfect vacuum would cause a depression of
+level in that leg to 30 inches below the level of the mercury
+in the leg connected with the condenser. In a more usual
+form, it consisted of a simple glass tube having its lower
+end immersed in a cistern of mercury, as in the ordinary
+barometer, the top of the tube being connected with a pipe
+leading to the condenser. With a perfect vacuum in the
+condenser, the mercury would rise in the tube very nearly
+30 inches. Ordinarily, the vacuum is not nearly perfect,
+and, a back pressure remaining in the condenser of one or
+two pounds per square inch, the atmospheric pressure remaining
+unbalanced is only sufficient to raise the mercury
+26 or 28 inches above the level of the liquid metal in the
+cistern.</p>
+
+<p>To determine the height of water in his boiler, Watt
+added to the gauge-cocks already long in use the &#8220;glass
+water-gauge,&#8221; which is still seen in nearly every well-arranged<span class='pagenum'><a name="Page_118" id="Page_118">[118]</a></span>
+boiler. This was a glass tube, <i>a a&#8242;</i> (<a href="#Fig30">Fig. 30</a>),
+mounted on a standard attached to the front of the boiler,
+and at such a height that its middle point was very little
+below the proposed water-level. It was connected by
+a small pipe, <i>r</i>, at the top to the steam-space, and another
+little pipe, <i>r&#8242;</i>, led into the boiler from its lower end
+below the water-line. As the water rose and fell within
+the boiler, its level changed correspondingly in the glass.
+This little instrument is especially liked, because the position
+of the water is at all times shown to the eye of the
+attendant. If carefully protected against sudden changes
+of temperature, it answers perfectly well with even very
+high pressures.</p>
+
+<div class="figcenter"><a name="Fig31" id="Fig31"></a>
+<img src="images/illo146.png" alt="Boulton &amp; Watt's Double Acting Engine" width="350" height="403" />
+<p class="caption"><span class="smcap">Fig. 31.</span>&mdash;Boulton &amp; Watt&#8217;s Double-Acting Engine, 1784.</p></div>
+
+<p>The engines built by Boulton &amp; Watt were finally fitted
+with the crank and fly-wheel for application to the driving
+of mills and machinery. The accompanying engraving
+(<a href="#Fig31">Fig. 31</a>) shows the engine as thus made, combining all of
+the essential improvements designed by its inventor.</p>
+
+<p>In the engraving, <i>C</i> is the steam-cylinder, <i>P</i> the piston,
+connected to the beam by the link, <i>g</i>, and guided by the
+parallel-motion, <i>g d c</i>. At the opposite end of the beam a
+connecting-rod, <i>O</i>, connects with the crank and fly-wheel
+shaft. <i>R</i> is the rod of the air-pump, by means of which
+the condenser is kept from being flooded by the water used
+for condensation, which water-supply is regulated by an
+&#8220;injection-handle,&#8221; <i>E</i>. A pump-rod, <i>N</i>, leads down from
+the beam to the cold-water pump, by which water is raised
+from the well or other source to supply the needed injection-water.
+The air-pump rod also serves as a &#8220;plug-rod,&#8221; to
+work the valves, the pins at <i>m</i> and <i>R</i> striking the lever, <i>m</i>,
+at either end of the stroke. When the piston reaches the
+top of the cylinder, the lever, <i>m</i>, is raised, opening the
+steam-valve, <i>B</i>, at the top, and the exhaust-valve, <i>E</i>, at the
+bottom, and at the same time closing the exhaust at the
+top and the steam at the bottom. When the entrance of
+steam at the top and the removal of steam-pressure below<span class='pagenum'><a name="Page_119" id="Page_119">[119]</a></span>
+the piston has driven the piston to the bottom, the pin, <i>R</i>,
+strikes the lever, <i>m</i>, opening the steam and closing the
+exhaust valve at the bottom, and similarly reversing the position
+of the valves at the top. The position of the valves is
+changed in this manner with every reversal of the motion
+of the piston as the crank &#8220;turns over the centre.&#8221;</p>
+
+<p>The earliest engines of the double-acting kind, and of
+any considerable size, which were built to turn a shaft, were
+those which were set up in the Albion Mills, near Blackfriars&#8217;
+Bridge, London, in 1786, and destroyed when the
+mills burned down in 1791. There were a pair of these
+engines (shown in <a href="#Fig27">Fig. 27</a>), of 50 horse-power each, and
+geared to drive 20 pairs of stones, making fine flour and
+meal. Previous to the erection of this mill the power
+in all such establishments had been derived from windmills
+and water-wheels. This mill was erected by Boulton<span class='pagenum'><a name="Page_120" id="Page_120">[120]</a></span>
+&amp; Watt, and capitalists working with them, not only
+to secure the profit anticipated from locating a flour-mill
+in the city of London, but also with a view to exhibiting
+the capacity of the new double-acting &#8220;rotating&#8221; engine.
+The plan was proposed in 1783, and work was commenced
+in 1784; but the mill was not set in operation until
+the spring of 1786. The capacity of the mill was, in ordinary
+work, 16,000 bushels of wheat ground into fine flour
+per week. On one occasion, the mill turned out 3,000 bushels
+in 24 hours. In the construction of the machinery of
+the mill, many improvements upon the then standard practice
+were introduced, including cast-iron gearing with carefully-formed
+teeth and iron framing. It was here that John
+Rennie commenced his work, after passing through his apprenticeship
+in Scotland, sending his chief assistant, Ewart,
+to superintend the erection of the milling machinery. The
+mill was a success as a piece of engineering, but a serious
+loss was incurred by the capitalists engaged in the enterprise,
+as it was set on fire a few years afterward and entirely
+destroyed. Boulton and Watt were the principal
+losers, the former losing &pound;6,000, and the latter &pound;3,000.</p>
+
+<div class="figcenter"><a name="Fig32" id="Fig32"></a>
+<img src="images/illo148.png" alt="Albion Mills Engine Valve Gear" width="294" height="500" />
+<p class="caption"><span class="smcap">Fig. 32.</span>&mdash;Valve-Gear of the Albion Mills Engine.</p></div>
+
+<p>The valve-gear of this engine, a view of which is given
+in <a href="#Fig27">Fig. 27</a>, was quite similar to that used on the Watt
+pumping-engine. The accompanying illustration (<a href="#Fig32">Fig. 32</a>)
+represents this valve-motion as attached to the Albion Mills
+engine.</p>
+
+<p>The steam-pipe, <i>a b d d e</i>, leads the steam from the boiler
+to the chambers, <i>b</i> and <i>e</i>. The exhaust-pipe, <i>g g</i>, leads
+from <i>h</i> and <i>i</i> to the condenser. In the sketch, the upper
+steam and the lower exhaust valves, <i>b</i> and <i>f</i>, are opened,
+and the steam-valve, <i>e</i>, and exhaust-valve, <i>c</i>, are closed, the
+piston being near the upper end of the cylinder and descending.
+<i>l</i> represents the plug-frame, which carries tappets,
+2 and 3, which engage the lever, <i>s</i>, at either end of its
+throw, and turn the shaft, <i>u</i>, thus opening and closing <i>c</i> and
+<i>e</i> simultaneously by means of the connecting-links, 13 and<span class='pagenum'><a name="Page_121" id="Page_121">[121]</a></span>
+14. A similar pair of tappets on the opposite side of the
+plug-rod move the valves, <i>b</i> and <i>f</i>, by means of the rods, 10
+and 11, the arm, <i>r</i>, when struck by those tappets, turning
+the shaft, <i>t</i>, and thus moving the arms to which those rods
+are attached. Counterbalance-weights, carried on the ends
+of the arms, 4 and 15, retain the valves on their seats when
+closed by the action of the tappets. When the piston
+nearly reaches the lower end of the cylinder, the tappet, 1,
+engages the arm, <i>r</i>, closing the steam-valve, <i>b</i>, and the next
+instant shutting the exhaust-valve, <i>f</i>. At the same time, the
+tappet, 3, by moving the arm, <i>s</i>, downward, opens the steam-valve,
+<i>e</i>, and the exhaust-valve, <i>c</i>. Steam now no longer
+issues from the steam-pipe into the space, <i>c</i>, and thence into
+the engine-cylinder (not shown in the sketch); but it now
+enters the engine through the valve, <i>e</i>, forcing the piston<span class='pagenum'><a name="Page_122" id="Page_122">[122]</a></span>
+upwards. The exhaust is simultaneously made to occur at
+the upper end, the rejected steam passing from the engine
+into the space, <i>c</i>, and thence through <i>c</i> and the pipe, <i>g</i>, into
+the condenser.</p>
+
+<p>This kind of valve-gear was subsequently greatly improved
+by Murdoch, Watt&#8217;s ingenious and efficient foreman,
+but it is now entirely superseded on engines of this
+class by the eccentric, and the various forms of valve-gear
+driven by it.</p>
+
+<div class="figcenter"><a name="Fig33" id="Fig33"></a>
+<img src="images/illo149.png" alt="Watt's Half-Trunk Engine" width="350" height="531" />
+<p class="caption"><span class="smcap">Fig. 33.</span>&mdash;Watt&#8217;s Half-Trunk Engine, 1784.</p></div>
+
+<p>The &#8220;trunk-engine&#8221; was still another of the almost innumerable
+inventions of Watt. A half-trunk engine is
+described in his patent of 1784, as shown in the accompanying
+sketch (<a href="#Fig33">Fig. 33</a>), in which <i>A</i> is the cylinder, <i>B</i> the
+piston, and <i>C</i> its rod, encased in the half-trunk, <i>D</i>. The
+plug-rod, <i>G</i>, moves the single pair of valves by striking the
+catches, <i>E</i> and <i>F</i>, as was usual with Watt&#8217;s earlier engines.</p>
+
+<p><span class='pagenum'><a name="Page_123" id="Page_123">[123]</a></span>Watt&#8217;s steam-hammer was patented at the same time.
+It is seen in <a href="#Fig34">Fig. 34</a>, in which <i>A</i> is the steam-cylinder and
+<i>B</i> its rod, the engine being evidently of the form just described.
+It works a beam, <i>C C</i>, which in turn, by the rod,
+<i>M</i>, works the hammer-helve, <i>L J</i>, and the hammer, <i>L</i>. The
+beam, <i>F G</i>, is a spring, and the block, <i>N</i>, the anvil.</p>
+
+<p>Watt found it impossible to determine the duty of his
+engines at all times by measurement of the work itself,
+and endeavored to find a way of ascertaining the power
+produced, by ascertaining the pressure of steam within
+the cylinder. This pressure was so variable, and subject
+to such rapid as well as extreme fluctuations, that
+he found it impossible to make use of the steam-gauge
+constructed for use on the boiler. He was thus driven to
+invent a special instrument for this work, which he called
+the &#8220;steam-engine indicator.&#8221; This consisted of a little
+steam-cylinder containing a nicely-fitting piston, which
+moved without noticeable friction through a range which
+was limited by the compression of a helical spring, by means
+of which the piston was secured to the top of its cylinder.
+The distance through which the piston rose was proportional
+to the pressure exerted upon it, and a pointer attached
+to its rod traversed a scale upon which the pressure
+per square inch could be read. The lower end of the instrument
+being connected with the steam-cylinder of the<span class='pagenum'><a name="Page_124" id="Page_124">[124]</a></span>
+engine by a small pipe fitted with a cock, the opening of
+the latter permitted steam from the engine-cylinder to fill
+the indicator-cylinder, and the pressure of steam was always
+the same in both cylinders. The indicator-pointer therefore
+traversed the pressure-scale, always exhibiting the
+pressure existing at the instant in the cylinder of the engine.
+When the engine was at rest and steam off, the indicator-piston
+stood at the same level as when detached from the
+engine, and the pointer stood at 0 on the scale. When
+steam entered, the piston rose and fell with the fluctuations
+of pressure; and when the exhaust-valve opened, discharging
+the steam and producing a vacuum in the steam-cylinder,
+the pointer of the indicator dropped below 0, showing
+the degree of exhaustion. Mr. Southern, one of Watt&#8217;s
+assistants, fitted the instrument with a sliding board, moved
+horizontally backward and forward by a cord or link-work
+connecting directly or indirectly with the engine-beam, and
+thus giving it a motion coincident with that of the piston.
+This board carried a piece of paper, upon which a pencil
+attached to the indicator piston-rod drew a curve. The
+vertical height of any point on this curve above the base-line
+measured the pressure in the cylinder at the moment
+when it was made, and the horizontal distance of the point
+from either end of the diagram determined the position, at
+the same moment, of the engine-piston. The curve thus
+inscribed, called the &#8220;indicator card,&#8221; or indicator diagram,
+exhibiting every minute change in the pressure of steam in
+the engine, not only enabled the mean pressure and the
+power of the engine to be determined by its measurement,
+but, to the eye of the expert engineer, it was a perfectly
+legible statement of the position of the valves of the engine,
+and revealed almost every defect in the action of the engine
+which could not readily be detected by external examination.
+It has justly been called the &#8220;engineers&#8217; stethoscope,&#8221;
+opening the otherwise inaccessible parts of the steam-engine
+to the inspection of the engineer even more satisfactorily<span class='pagenum'><a name="Page_125" id="Page_125">[125]</a></span>
+than the stethoscope of the physician gives him a knowledge
+of the condition and working of organs contained
+within the human body. This indispensable and now familiar
+engineers&#8217; instrument has since been modified and
+greatly improved in detail.</p>
+
+<div class="figcenter"><a name="Fig34" id="Fig34"></a>
+<img src="images/illo150.png" alt="Watt's Steam Hammer" width="350" height="229" />
+<p class="caption"><span class="smcap">Fig. 34.</span>&mdash;The Watt Hammer, 1784.</p></div>
+
+<p>The Watt engine had, by the construction of the improvements
+described in the patents of 1782-&#8217;85, been given
+its distinctive form, and the great inventor subsequently
+did little more than improve it by altering the forms and
+proportions of its details. As thus practically completed,
+it embodied nearly all the essential features of the modern
+engine; and, as we have seen, the marked features of our
+latest practice&mdash;the use of the double cylinder for expansion,
+the cut-off valve-gear, and surface-condensation&mdash;had
+all been proposed, and to a limited extent introduced. The
+growth of the steam-engine has here ceased to be rapid, and
+the changes which followed the completion of the work of
+James Watt have been minor improvements, and rarely, if
+ever, real developments.</p>
+
+<p>Watt&#8217;s mind lost none of its activity, however, for many
+years. He devised and patented a &#8220;smoke-consuming furnace,&#8221;
+in which he led the gases produced on the introduction
+of fresh fuel over the already incandescent coal, and
+thus burned them completely. He used two fires, which
+were coaled alternately. Even when busiest, also, he found
+time to pursue more purely scientific studies. With Boulton,
+he induced a number of well-known scientific men living
+near Birmingham to join in the formation of a &#8220;Lunar
+Society,&#8221; to meet monthly at the houses of its members, &#8220;at
+the full of the moon.&#8221; The time was thus fixed in order
+that those members who came from a distance should be
+able to drive home, after the meetings, by moonlight.
+Many such societies were then in existence in England; but
+that at Birmingham was one of the largest and most distinguished
+of them all. Boulton, Watt, Drs. Small, Darwin,
+and Priestley, were the leaders, and among their occasional<span class='pagenum'><a name="Page_126" id="Page_126">[126]</a></span>
+visitors were Herschel, Smeaton, and Banks. Watt
+called these meetings &#8220;Philosophers&#8217; meetings.&#8221; It was
+during the period of most active discussion at the &#8220;philosophers&#8217;
+meetings&#8221; that Cavendish and Priestley were experimenting
+with mixtures of oxygen and hydrogen, to determine
+the nature of their combustion. Watt took much
+interest in the subject, and, when informed by Priestley
+that he and Cavendish had both noticed a deposit of moisture
+invariably succeeding the explosion of the mixed gases,
+when contained in a cold vessel, and that the weight of this
+water was approximately equal to the weight of the mixed
+gases, he at once came to the conclusion that the union of
+hydrogen with oxygen produced water, the latter being a
+chemical compound, of which the former were constituents.
+He communicated this reasoning, and the conclusions to
+which it had led him, to Boulton, in a letter written in December,
+1782, and addressed a letter some time afterward
+to Priestley, which was to have been read before the Royal
+Society in April, 1783. The letter was not read, however,
+until a year later, and, three months after, a paper by Cavendish,
+making the same announcement, had been laid before
+the Society. Watt stated that both Cavendish and Lavoisier,
+to whom also the discovery is ascribed, received the
+idea from him.</p>
+
+<p>The action of chlorine in bleaching organic coloring-matters,
+by (as since shown) decomposing them and combining
+with their hydrogen, was made known to Watt by
+M. Berthollet, the distinguished French chemist, and the
+former immediately introduced its use into Great Britain,
+by inducing his father-in-law, Mr. Macgregor, to make a
+trial of it.</p>
+
+<p>The copartnership of Boulton &amp; Watt terminated by
+limitation, and with the expiration of the patents under
+which they had been working, in the first year of the present
+century; and both partners, now old and feeble, withdrew
+from active business, leaving their sons to renew the agreement<span class='pagenum'><a name="Page_127" id="Page_127">[127]</a></span>
+and to carry on the business under the same firm-style.</p>
+
+<p>Boulton, however, still interested himself in some
+branches of manufacture, especially in his mint, where he
+had coined many years and for several nations.</p>
+
+<p>Watt retired, a little later, to Heathfield, where he
+passed the remainder of his life in peaceful enjoyment of
+the society of his friends, in studies of all current matters
+of interest in science, as well as in engineering. One by
+one his old friends died&mdash;Black in 1799, Priestley, an exile
+to America, in 1803, and Robison a little later. Boulton
+died, at the age of eighty-one, August 17, 1809, and even
+the loss of this nearest and dearest of his friends outside the
+family was a less severe blow than that of his son Gregory,
+who died in 1804.</p>
+
+<p>Yet the great engineer and inventor was not depressed
+by the loneliness which was gradually coming upon him.
+He wrote: &#8220;I know that all men must die, and I submit
+to the decrees of Nature, I hope, with due reverence to
+the Disposer of events;&#8221; and neglected no opportunity to
+secure amusement or instruction, and kept body and mind
+constantly occupied. He still attended the weekly meetings
+of the club, meeting Rennie and Telford, and other
+distinguished men of his own and the succeeding generation.
+He lost nothing of his fondness for invention, and
+spent many months in devising a machine for copying
+statuary, which he had not perfected to his own satisfaction
+at the time of his death, ten years later. This machine
+was a kind of pentagraph, which could be worked
+in any plane, and in which the marking-pencil gave place
+to a cutting-tool. The tracing-point followed the surface
+of the pattern, while the cutting-point, following its motion
+precisely, formed a fac-simile in the material operated
+upon.</p>
+
+<p>In the year 1800 he invented the water-main which was
+laid down by the Glasgow Water-Works Company across<span class='pagenum'><a name="Page_128" id="Page_128">[128]</a></span>
+the Clyde. The joints were spherical and articulated, like
+those of the lobster&#8217;s tail.</p>
+
+<p>His workshop, of which a <a href="#Fig28">sketch</a> is hereafter given, as
+drawn by the artist Skelton, was in the garret of his house,
+and was well supplied with tools and all kinds of laboratory
+material. His lathe and his copying-machine were placed
+before the window, and his writing-desk in the corner.
+Here he spent the greater part of his leisure time, often
+even taking his meals in the little shop, rather than go to
+the table for them. Even when very old, he occasionally
+made a journey to London or Glasgow, calling on his old
+friends and studying the latest engineering devices and inspecting
+public works, and was everywhere welcomed by
+young and old as the greatest living engineer, or as the kind
+and wise friend of earlier days.</p>
+
+<p>He died August 19, 1819, in the eighty-third year of his
+age, and was buried in Handsworth Church. The sculptor
+Chantrey was employed to place a fitting monument above
+his grave, and the nation erected a statue of the great man
+in Westminster Abbey.</p>
+
+<p>This sketch of the greatest of all the inventors of the
+steam-engine has been given no greater length than its subject
+justifies. Whether we consider Watt as the inventor
+of the standard steam-engine of the nineteenth century, as
+the scientific investigator of the physical principles upon
+which the invention is based, or as the builder and introducer
+of the most powerful known instrument by which the
+&#8220;great sources of power in Nature are converted, adapted,
+and applied for the use and convenience of man,&#8221; he is fully
+entitled to pre&euml;minence. His character as a man was no
+less admirable than as an engineer.</p>
+
+<div class="figcenter"><a name="Fig35" id="Fig35"></a>
+<img src="images/illo156.png" alt="Watt's Workshop" width="400" height="260" />
+<p class="caption"><span class="smcap">Fig. 35.</span>&mdash;James Watt&#8217;s Workshop.<br />(From Smiles&#8217;s &#8220;Lives
+of Boulton and Watt.&#8221;)</p></div>
+
+<p>Smiles, Watt&#8217;s most conscientious and indefatigable
+biographer, writes:<a name="FNanchor_41_41" id="FNanchor_41_41"></a><a href="#Footnote_41_41" class="fnanchor">[41]</a></p>
+
+<p>&#8220;Some months since, we visited the little garret at<span class='pagenum'><a name="Page_129" id="Page_129">[129]</a></span>
+Heathfield in which Watt pursued the investigations
+of his later years. The room had been carefully locked
+up since his death, and had only once been swept out.
+Everything lay very much as he left it. The piece of<span class='pagenum'><a name="Page_130" id="Page_130">[130]</a></span>
+iron which he was last employed in turning, lay on the
+lathe. The ashes of the last fire were in the grate; the last
+bit of coal was in the scuttle. The Dutch oven was in its
+place over the stove, and the frying-pan in which he cooked
+his meals was hanging on its accustomed nail. Many objects
+lay about or in the drawers, indicating the pursuits
+which had been interrupted by death&mdash;busts, medallions,
+and figures, waiting to be copied by the copying-machine&mdash;many
+medallion-moulds, a store of plaster-of-Paris, and a
+box of plaster casts from London, the contents of which do
+not seem to have been disturbed. Here are Watt&#8217;s ladles
+for melting lead, his foot-rule, his glue-pot, his hammer.
+Reflecting mirrors, an extemporized camera with the lenses
+mounted on pasteboard, and many camera-glasses laid about,
+indicate interrupted experiments in optics. There are quadrant-glasses,
+compasses, scales, weights, and sundry boxes
+of mathematical instruments, once doubtless highly prized.
+In one place a model of the governor, in another of the
+parallel-motion, and in a little box, fitted with wooden cylinders
+mounted with paper and covered with figures, is what
+we suppose to be a model of his calculating-machine. On
+the shelves are minerals and chemicals in pots and jars, on
+which the dust of nearly half a century has settled. The
+moist substances have long since dried up; the putty has
+been turned to stone, and the paste to dust. On one shelf
+we come upon a dish in which lies a withered bunch of
+grapes. On the floor, in a corner, near to where Watt sat
+and worked, is a hair-trunk&mdash;a touching memorial of a long-past
+love and a long-dead sorrow. It contains all poor
+Gregory&#8217;s school-books, his first attempts at writing, his
+boy&#8217;s drawings of battles, his first school-exercises down to
+his college-themes, his delectuses, his grammars, his dictionaries,
+and his class-books&mdash;brought into this retired room,
+where the father&#8217;s eye could rest upon them. Near at hand
+is the sculpture-machine, on which he continued working to
+the last. Its wooden frame is worm-eaten, and dropping<span class='pagenum'><a name="Page_131" id="Page_131">[131]</a></span>
+into dust, like the hands that made it. But though the
+great workman is gone to rest, with all his griefs and cares,
+and his handiwork is fast crumbling to decay, the spirit of
+his work, the thought which he put into his inventions, still
+survives, and will probably continue to influence the destinies
+of his race for all time to come.&#8221;</p>
+
+<p>The visitor to Westminster Abbey will find neither monarch,
+nor warrior, nor statesman, nor poet, honored with a
+nobler epitaph than that which is inscribed on the pedestal
+of Chantrey&#8217;s monument to Watt:</p>
+
+<p class="center" style="line-height: 1.75em;">
+<span class="smcap">Not to perpetuate a Name</span>,<br />
+<span class="fsize80">WHICH MUST ENDURE WHILE THE PEACEFUL ARTS FLOURISH,<br />
+BUT TO SHOW<br />
+THAT MANKIND HAVE LEARNT TO HONOR THOSE WHO BEST DESERVE THEIR<br />
+GRATITUDE,</span><br />
+<span class="fsize125"><span class="gesp">THE KIN</span>G,</span><br />
+<span class="fsize80">HIS MINISTERS, AND MANY OF THE NOBLES AND COMMONERS OF THE REALM,<br />
+RAISED THIS MONUMENT TO</span><br />
+<span class="fsize150"><span class="gesp">JAMES WAT</span>T,</span><br />
+<span class="fsize80">WHO, DIRECTING THE FORCE OF AN ORIGINAL GENIUS,<br />
+EARLY EXERCISED IN PHILOSOPHIC RESEARCH,<br />
+TO THE IMPROVEMENT OF</span><br />
+<span class="fsize125"><span class="gesp">THE STEAM-ENGIN</span>E,</span><br />
+<span class="fsize80">ENLARGED THE RESOURCES OF HIS COUNTRY, INCREASED THE POWER OF MAN,<br />
+AND ROSE TO AN EMINENT PLACE<br />
+AMONG THE MOST ILLUSTRIOUS FOLLOWERS OF SCIENCE AND THE REAL<br />
+BENEFACTORS OF THE WORLD.</span><br />
+<span class="smcap">Born at Greenock, MDCCXXXVI.<br />
+Died at Heathfield, in Staffordshire, MDCCCXIX.</span></p>
+
+<p class='pagenum'><a name="Page_132" id="Page_132">[132]</a></p>
+
+<div class="figcenter"><a name="Fig_Watts_Tomb" id="Fig_Watts_Tomb"></a>
+<img src="images/illo159.png" alt="Watt's Tomb" width="365" height="350" />
+<p class="caption" >Tomb of James Watt.</p></div>
+
+<hr class="c05" />
+<h4><span class="smcap">Section II.&mdash;The Contemporaries of James Watt.</span></h4>
+<hr class="c05" />
+
+<p>In the chronology of the steam-engine, the contemporaries
+of Watt have been so completely overshadowed by the
+greater and more successful inventor, as to have been almost
+forgotten by the biographer and by the student of history.
+Yet, among the engineers and engine-builders, as well as
+among the inventors of his day, Watt found many enterprising
+rivals and keen competitors. Some of these men, had
+they not been so completely fettered by Watt&#8217;s patents,
+would have probably done work which would have entitled
+them to far higher honor than has been accorded them.</p>
+
+<p><span class="smcap">William Murdoch</span> was one of the men to whom Watt,
+no less than the world, was greatly indebted. For many years
+he was the assistant, friend, and coadjutor of Watt; and it
+is to his ingenuity that we are to give credit for not only<span class='pagenum'><a name="Page_133" id="Page_133">[133]</a></span>
+many independent inventions, but also for the suggestions
+and improvements which were often indispensable to the
+formation and perfection of some of Watt&#8217;s own inventions.</p>
+
+<p>Murdoch was employed by Boulton &amp; Watt in 1776,
+and was made superintendent of construction in the engine
+department, and given general charge of the erection of engines.
+He was sent into Cornwall, and spent in that district
+much of the time during which he served the firm, erecting
+pumping-engines, the construction of which for so
+many years constituted a large part of the business of the
+Soho establishment. He was looked upon by both Boulton
+and Watt as a sincere friend, as well as a loyal adherent,
+and from 1810 to 1830 was given a partner&#8217;s share of the
+income of the firm, and a salary of &pound;1,000. He retired from
+business at the last of the two dates named, and, dying in
+1839, was buried near the two partners in Handsworth
+Church.</p>
+
+<div class="figcenter"><a name="Fig36" id="Fig36"></a>
+<img src="images/illo161.png" alt="Murdoch's Oscillating Engine" width="270" height="350" />
+<p class="caption"><span class="smcap">Fig. 36.</span>&mdash;Murdoch&#8217;s Oscillating Engine, 1785.</p></div>
+
+<p>Murdoch made a model, in 1784, of the locomotive patented
+by Watt in that year. He devised the arrangement
+of &#8220;sun-and-planet wheels,&#8221; adopted for a time in all of
+Watt&#8217;s &#8220;rotative&#8221; engines, and invented the oscillating
+steam-engine (<a href="#Fig36">Fig. 36</a>) in 1785, using the &#8220;D-slide valves,&#8221;
+<i>G</i>, moved by the gear, <i>E</i>, which was driven by an eccentric
+on the shaft, without regard to the oscillation of the cylinder,
+<i>A</i>. He was the inventor of a rotary engine and of
+many minor machines for special purposes, and of many
+machine-tools used at Soho in building engines and machines.
+He seems, like Watt, to have had special fondness
+for the worm-gear, and introduced it wherever it could
+properly take the place of ordinary gearing. Some of the
+machines designed by Watt and Murdoch, who always
+worked well together, were found still in use and in good
+working condition by the author when visiting the works at
+Soho in 1873. The old mint in which, from 1797 to 1805,
+Boulton had coined 4,000 tons of copper, had then been
+pulled down, and a new mint had been erected in 1860.<span class='pagenum'><a name="Page_134" id="Page_134">[134]</a></span>
+Many old machines still remained about the establishment
+as souvenirs of the three great mechanics.</p>
+
+<p>Outside of Soho, Murdoch also found ample employment
+for his inventive talent. In 1792, while at Redruth, his
+residence before finally returning to Soho, he was led to
+speculate upon the possibility of utilizing the illuminating
+qualities of coal-gas, and, convinced of its practicability, he
+laid the subject before the Royal Society in 1808, and was
+awarded the Rumford gold medal. He had, ten years earlier,
+lighted a part of the Soho works with coal-gas, and in
+1803 Watt authorized him to extend his pipes throughout
+all the buildings. Several manufacturers promptly introduced
+the new light, and its use extended very rapidly.</p>
+
+<p>Still another of Murdoch&#8217;s favorite schemes was the
+transmission of power by the use of compressed air. He
+drove the pattern-shop engine at Soho by means of air from
+the blowing-engine in the foundery, and erected a pneumatic
+lift to elevate castings from the foundery-floor to the canal-bank.<span class='pagenum'><a name="Page_135" id="Page_135">[135]</a></span>
+He made a steam-gun, introduced the heating of
+buildings by the circulation of hot water, and invented the
+method of transmitting packages through tubes by the impulse
+of compressed air, as now practised by the &#8220;pneumatic
+dispatch&#8221; companies. He died at the age of eighty-five
+years.</p>
+
+<div class="figcenter"><a name="Fig37" id="Fig37"></a>
+<img src="images/illo163.png" alt="Hornblower's Compound Engine" width="400" height="476" />
+<p class="caption"><span class="smcap">Fig. 37.</span>&mdash;Hornblower&#8217;s Compound Engine, 1781.</p></div>
+
+<p>Among the most active and formidable of Watt&#8217;s business
+rivals was <span class="smcap">Jonathan Hornblower</span>, the patentee of
+the &#8220;compound&#8221; or double-cylinder engine. A sketch of
+this engine, as patented by Hornblower in 1781, is here
+given (<a href="#Fig37">Fig. 37</a>). It was first described by the inventor in
+the &#8220;Encyclop&aelig;dia Britannica.&#8221; It consists, as is seen by
+reference to the engraving, of two steam-cylinders, <i>A</i> and
+<i>B</i>&mdash;<i>A</i> being the low and <i>B</i> the high pressure cylinder&mdash;the
+steam leaving the latter being exhausted into the former,
+and, after doing its work there, passing into the condenser,
+as already described. The piston-rods, <i>C</i> and <i>D</i>, are both
+connected to the same part of the beam by chains, as in the
+other early engines. These rods pass through stuffing-boxes
+in the cylinder-heads, which are fitted up like those seen on
+the Watt engine. Steam is led to the engine through the
+pipe, <i>G Y</i>, and cocks, <i>a</i>, <i>b</i>, <i>c</i>, and <i>d</i>, are adjustable, as required,
+to lead steam into and from the cylinders, and are
+moved by the plug-rod, <i>W</i>, which actuates handles not
+shown. <i>K</i> is the exhaust-pipe leading to the condenser. <i>V</i>
+is the engine feed-pump rod, and <i>X</i> the great rod carrying
+the pump-buckets at the bottom of the shaft.</p>
+
+<p>The cocks <i>c</i> and <i>a</i> being open and <i>b</i> and <i>d</i> shut, the
+steam passes from the boiler into the upper part of the
+steam-cylinder, <i>B</i>; and the communication between the
+lower part of <i>B</i> and the top of <i>A</i> is also open. Before
+starting, steam being shut off from the engine, the great
+weight of the pump-rod, <i>X</i>, causes that end of the beam to
+preponderate, the pistons standing, as shown, at the top of
+their respective steam-cylinders.</p>
+
+<p>The engine being freed from all air by opening all the<span class='pagenum'><a name="Page_136" id="Page_136">[136]</a></span>
+valves and permitting the steam to drive it through the engine
+and out of the condenser through the &#8220;snifting-valve,&#8221;
+<i>O</i>, the valves <i>b</i> and <i>d</i> are closed, and the cock in the exhaust-pipe opened.</p>
+
+<p>The steam beneath the piston of the large cylinder is
+immediately condensed, and the pressure on the upper side
+of that piston causes it to descend, carrying that end of the
+beam with it, and raising the opposite end with the pump-rods
+and their attachments. At the same time, the steam
+from the lower end of the small high-pressure cylinder being
+let into the upper end of the larger cylinder, the completion
+of the stroke finds a cylinder full of steam transferred from
+the one to the other with corresponding increase of volume
+and decrease of pressure. While expanding and diminishing
+in pressure as it passes from the smaller into the larger<span class='pagenum'><a name="Page_137" id="Page_137">[137]</a></span>
+cylinder, this charge of steam gradually resists less and less
+the pressure of the steam from the boiler on the upper side
+of the piston of the small cylinder, <i>B</i>, and the net result is
+the movement of the engine by pressures exerted on the
+upper sides of both pistons and against pressures of less intensity
+on the under sides of both. The pressures in the
+lower part of the small cylinder, in the upper part of the
+large cylinder, and in the communicating passage, are evidently
+all equal at any given time.</p>
+
+<p>When the pistons have reached the bottoms of their respective
+cylinders, the valves at the top of the small cylinder,
+<i>B</i>, and at the bottom of the large cylinder, <i>A</i>, are
+closed, and the valves <i>c</i> and <i>d</i> are opened. Steam from
+the boiler now enters beneath the piston of the small cylinder;
+the steam in the larger cylinder is exhausted into
+the condenser, and the steam already in the small cylinder
+passes over into the large cylinder, following up the piston
+as it rises.</p>
+
+<p>Thus, at each stroke a small cylinder full of steam is
+taken from the boiler, and the same weight, occupying the
+volume of the larger cylinder, is exhausted into the condenser
+from the latter cylinder.</p>
+
+<p>Referring to the method of operation of this engine,
+Prof. Robison demonstrated that the effect produced was
+the same as in Watt&#8217;s single-cylinder engine&mdash;a fact which
+is comprehended in the law enunciated many years later by
+Rankine, that, &#8220;so far as the theoretical action of the steam
+on the piston is concerned, it is immaterial whether the
+expansion takes place in one cylinder, or in two or more
+cylinders.&#8221; It was found, in practice, that the Hornblower
+engine was no more economical than the Watt engine;
+and that erected at the Tin Croft Mine, Cornwall, in 1792,
+did even less work with the same fuel than the Watt engines.</p>
+
+<p>Hornblower was prosecuted by Boulton &amp; Watt for
+infringement. The suit was decided against him, and he<span class='pagenum'><a name="Page_138" id="Page_138">[138]</a></span>
+was imprisoned in default of payment of the royalty, and
+fine demanded. He died a disappointed and impoverished
+man. The plan thus unsuccessfully introduced by Hornblower
+was subsequently modified and adopted by others
+among the contemporaries of Watt; and, with higher steam
+and the use of the Watt condenser, the &#8220;compound&#8221; gradually
+became a standard type of steam-engine.</p>
+
+<p>Arthur Woolf, in 1804, re-introduced the Hornblower or
+Falck engine, with its two steam-cylinders, using steam of
+higher tension. His first engine was built for a brewery in
+London, and a considerable number were subsequently
+made. Woolf expanded his steam from six to nine times,
+and the pumping-engines built from his plans were said to
+have raised about 40,000,000 pounds one foot high per bushel
+of coals, when the Watt engine was raising but little more
+than 30,000,000. In one case, a duty of 57,000,000 was
+claimed.</p>
+
+<div class="figcenter"><a name="Fig38" id="Fig38"></a>
+<img src="images/illo166.png" alt="Bull's Pumping Engine" width="323" height="500" />
+<p class="caption"><span class="smcap">Fig. 38.</span>&mdash;Bull&#8217;s Pumping-Engine, 1798.</p>
+<p class="center fsize80"><a href="images/large166.png">Large scale image</a> (434 kB).</p></div>
+
+<p>The most successful of those competitors of Watt who
+endeavored to devise a peculiar form of pumping-engine,
+which should have the efficiency of that of Boulton &amp; Watt,
+and the necessary advantage in first cost, were <span class="smcap">William
+Bull</span> and <span class="smcap">Richard Trevithick</span>.<a name="FNanchor_42_42" id="FNanchor_42_42"></a><a
+href="#Footnote_42_42" class="fnanchor">[42]</a> The accompanying
+<a href="#Fig38">illustration</a> shows the design, which was then known as
+the &#8220;Bull Cornish Engine.&#8221;</p>
+
+<p>The steam-cylinder, <i>a</i>, is carried on wooden beams, <i>b</i>,
+extending across the engine-house directly over the pump-well.
+The piston-rod, <i>c</i>, is secured to the pump-rods,
+<i>d d</i>, the cylinder being inverted, and the pumps, <i>e</i>, in the
+shaft, <i>f</i>, are thus operated without the intervention of
+the beam invariably seen in Watt&#8217;s engines. A connecting-rod,
+<i>g</i>, attached to the pump-rod and to the end of a
+balance-beam, <i>h</i>, operates the latter, and is counterbalanced
+by a weight, <i>i</i>. The rod, <i>j</i>, serves both as a plug-rod and
+as an air-pump connecting-rod. A snifting-valve, <i>k</i>, opens<span class='pagenum'><a name="Page_139" id="Page_139">[139]</a></span>
+when the engine is blown through, and relieves the condenser
+and air-pump, <i>l</i>, of all air. The rod, <i>m</i>, operates a
+solid air-pump piston, the valves of the pump being placed
+on either side at the base, instead of in the pump-bucket, as<span class='pagenum'><a name="Page_140" id="Page_140">[140]</a></span>
+in Watt&#8217;s engines. The condensing-water cistern was a
+wooden tank, <i>n</i>. A jet &#8220;pipe-condenser,&#8221; <i>o</i>, was used
+instead of a jet condenser of the form adopted by other
+makers, and was supplied with water through the cock, <i>p</i>.
+The plug-rod, <i>q</i>, as it rises and falls with the pump-rods
+and balance-beam, operates the &#8220;gear-handles,&#8221; <i>r r</i>, and
+opens and closes the valves, <i>s s</i>, at the required points in
+the stroke. The attendant works these valves by hand, in
+starting, from the floor, <i>t</i>. The operation of the engine
+is similar to that of a Watt engine. It is still in use,
+with a few modifications and improvements, and is a very
+economical and durable machine. It has not been as generally
+adopted, however, as it would probably have been had
+not the legal proscription of Watt&#8217;s patents so seriously interfered
+with its introduction. Its simplicity and lightness are
+decided advantages, and its designers are entitled to great
+credit for their boldness and ingenuity, as displayed in their
+application of the minor devices which distinguish the engine.
+The design is probably to be credited to Bull originally;
+but Trevithick built some of these engines, and is
+supposed to have greatly improved them while working
+with Edward Bull, the son of the inventor, William Bull.
+One of these engines was erected by them at the Herland
+Mine, Cornwall, in 1798, which had a steam-cylinder
+60 inches in diameter, and was built on the plan just described.</p>
+
+<p>Another of the contemporaries of James Watt was a
+clergyman, <span class="smcap">Edward Cartwright</span>, the distinguished inventor
+of the power-loom, and of the first machine ever used in
+combing wool, who revived Watt&#8217;s plan of surface-condensation
+in a somewhat modified form. Watt had made a
+&#8220;pipe-condenser,&#8221; similar in plan to those now often used,
+but had simply immersed it in a tank of water, instead of in
+a constantly-flowing stream. Cartwright proposed to use
+two concentric cylinders or spheres, between which the
+steam entered when exhausted from the cylinder of the engine,<span class='pagenum'><a name="Page_141" id="Page_141">[141]</a></span>
+and was condensed by contact with the metal surfaces.
+Cold water within the smaller and surrounding the exterior
+vessel kept the metal cold, and absorbed the heat discharged
+by the condensing vapor.</p>
+
+<div class="figcenter"><a name="Fig39" id="Fig39"></a>
+<img src="images/illo168.png" alt="Cartwright's Engine" width="350" height="453" />
+<p class="caption"><span class="smcap">Fig. 39.</span>&mdash;Cartwright&#8217;s Engine, 1798.</p></div>
+
+<p>Cartwright&#8217;s engine is best described in the <i>Philosophical
+Magazine</i> of June, 1798, from which the accompanying
+<a href="#Fig39">sketch</a> is copied.</p>
+
+<p>The object of the inventor is stated to have been to
+remedy the defects of the Watt engine&mdash;imperfect vacuum,
+friction, and complication.</p>
+
+<p>In the figure, the steam-cylinder takes steam through
+the pipe, <i>B</i>. The piston, <i>R</i>, has a rod extending downward
+to the smaller pump-piston, <i>G</i>, and upward to the
+cross-head, which, in turn, drives the cranks above, by
+means of connecting-rods. The shafts thus turned are connected<span class='pagenum'><a name="Page_142" id="Page_142">[142]</a></span>
+by a pair of gears, <i>M L</i>, of which one drives a
+pinion on the shaft of the fly-wheel. <i>D</i> is the exhaust-pipe
+leading to the condenser, <i>F</i>; and the pump, <i>G</i>, removes
+the air and water of condensation, forcing it into
+the hot-well, <i>H</i>, whence it is returned to the boiler through
+the pipe, <i>I</i>. A float in <i>H</i> adjusts an air-valve, so as to
+keep a supply of air in the chamber, to serve as a cushion
+and to make an air-chamber of the reservoir, and permits
+the excess to escape. The large tank contains the water
+supplied for condensing the steam.</p>
+
+<p>The piston, <i>R</i>, is made of metal, and is packed with
+two sets of cut metal rings, forced out against the sides of
+the cylinder by steel springs, the rings being cut at three
+points in the circumference, and kept in place by the springs.
+The arrangement of the two cranks, with their shafts and
+gears, is intended to supersede Watt&#8217;s plan for securing a
+perfectly rectilinear movement of the head of the piston-rod,
+without friction.</p>
+
+<p>In the accounts given of this engine, great stress is laid
+upon the supposed important advantage here offered, by the
+introduction of the surface-condenser, of permitting the employment
+of a working-fluid other than steam&mdash;as, for example,
+alcohol, which is too valuable to be lost. It was
+proposed to use the engine in connection with a still, and
+thus to effect great economy by making the fuel do double
+duty. The only part of the plan which proved both novel
+and valuable was the metallic packing and piston, which
+has not yet been superseded. The engine itself never came
+into use.</p>
+
+<p>At this point, the history of the steam-engine becomes
+the story of its applications in several different directions,
+the most important of which are the raising of water&mdash;which
+had hitherto been its only application&mdash;the locomotive-engine,
+the driving of mill-machinery, and steam-navigation.</p>
+
+<p>Here we take leave of James Watt and of his contemporaries,<span class='pagenum'><a name="Page_143" id="Page_143">[143]</a></span>
+of the former of whom a French author<a name="FNanchor_43_43" id="FNanchor_43_43"></a><a href="#Footnote_43_43" class="fnanchor">[43]</a>
+says: &#8220;The
+part which he played in the mechanical applications of the
+power of steam can only be compared to that of Newton in
+astronomy and of Shakespeare in poetry.&#8221; Since the time
+of Watt, improvements have been made principally in matters
+of mere detail, and in the extension of the range of
+application of the steam-engine.</p>
+
+<hr class="l05" />
+<div class="colleft">
+
+<div class="footnote"><p class="left"><a name="Footnote_35_35" id="Footnote_35_35"></a><a href="#FNanchor_35_35"><span class="label">[35]</span></a> The same story is told of Savery and of Worcester.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_36_36" id="Footnote_36_36"></a><a href="#FNanchor_36_36"><span class="label">[36]</span></a> Robison&#8217;s &#8220;Mechanical Philosophy,&#8221; edited by Brewster.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_37_37" id="Footnote_37_37"></a><a href="#FNanchor_37_37"><span class="label">[37]</span></a> &#8220;Reminiscences of James Watt,&#8221; Robert Hart; &#8220;Transactions of the
+Glasgow Arch&aelig;ological Society,&#8221; 1859.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_38_38" id="Footnote_38_38"></a><a href="#FNanchor_38_38"><span class="label">[38]</span></a> &#8220;Lives of Boulton and Watt,&#8221; Smiles.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_39_39" id="Footnote_39_39"></a><a href="#FNanchor_39_39"><span class="label">[39]</span></a> For the privilege of using the fly-wheel to regulate the motion of the
+engine, Boulton &amp; Watt paid a royalty to Matthew Wasborough, who had
+patented it, and who held also the patent for its combination with a crank,
+as invented by Pickard and Steed.</p></div>
+</div>
+
+<div class="footnote"><p class="left"><a name="Footnote_40_40" id="Footnote_40_40"></a><a href="#FNanchor_40_40"><span class="label">[40]</span></a> &#8220;Lives of Boulton and Watt,&#8221; Smiles.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_41_41" id="Footnote_41_41"></a><a href="#FNanchor_41_41"><span class="label">[41]</span></a> &#8220;Life of Watt,&#8221; p. 512.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_42_42" id="Footnote_42_42"></a><a href="#FNanchor_42_42"><span class="label">[42]</span></a> For an exceedingly interesting and very faithful account of their
+work, <i>see</i> &#8220;Life of Richard Trevithick,&#8221; by F. Trevithick, London, 1872.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_43_43" id="Footnote_43_43"></a><a href="#FNanchor_43_43"><span class="label">[43]</span></a> Bataille. &#8220;Trait&eacute; des Machines &agrave; Vapeur,&#8221; Paris, 1847.</p></div>
+
+<hr class="l05" />
+
+<div class="figcenter"><img src="images/illo170.png" alt="Ornament" width="250" height="222" /></div>
+
+<hr class="c40" /><p><span class='pagenum'><a name="Page_144" id="Page_144">[144]</a></span></p>
+
+<h2><a name="CHAPTER_IV" id="CHAPTER_IV"></a>CHAPTER IV.</h2>
+
+<h3><i>THE MODERN STEAM-ENGINE.</i></h3>
+<hr class="c05" />
+
+<div class="blockquot"><p>&#8220;Those projects which abridge distance have done most for the civilization
+and happiness of our species.&#8221;&mdash;<span class="smcap">Macaulay.</span></p></div>
+
+<hr class="c05" />
+<h4><span class="smcap">The Second Period of Application&mdash;1800-&#8217;40.
+Steam-Locomotion on Railroads.</span></h4>
+<hr class="c05" />
+
+<div class="figcenter"><a name="Fig40" id="Fig40"></a>
+<img src="images/illo171.png" alt="First Railroad-Car" width="350" height="234" />
+<p class="caption"><span class="smcap">Fig. 40.</span>&mdash;The First Railroad-Car, 1825.</p></div>
+
+<p>Introductory.&mdash;The commencement of the nineteenth
+century found the modern steam-engine fully developed in
+all its principal features, and fairly at work in many departments
+of industry. The genius of Worcester, and Morland,
+and Savery, and Desaguliers, had, in the first period of the<span class='pagenum'><a name="Page_145" id="Page_145">[145]</a></span>
+application of the power of steam to useful work, effected a
+beginning which, looked upon from a point of view which
+exhibits its importance as the first step toward the wonderful
+results to-day familiar to every one, appears in its true
+light, and entitles those great men to even greater honor
+than has been accorded them. The results actually accomplished,
+however, were absolutely insignificant in comparison
+with those which marked the period of development
+just described. Yet even the work of Watt and of his contemporaries
+was but a mere prelude to the marvellous advances
+made in the succeeding period, to which we are now
+come, and, in extent and importance, was insignificant in
+comparison with that accomplished by their successors in
+the development of all mechanical industries by the application
+of the steam-engine to the movement of every kind
+of machine.</p>
+
+<p>The first of the two periods of application saw the steam-engine
+adapted simply to the elevation of water and the
+drainage of mines; during the second period it was adapted
+to every variety of useful work, and introduced wherever
+the muscular strength of men and animals, or the power of
+wind and of falling water, which had previously been the
+only motors, had found application. A history of the development
+of industries by the introduction of steam-power
+during this period, would be no less extended and hardly
+less interesting than that of the steam-engine itself.</p>
+
+<p>The way had been fairly opened by Boulton and Watt;
+and the year 1800 saw a crowd of engineers and manufacturers
+entering upon it, eager to reap the harvest of distinction
+and of pecuniary returns which seemed so promising to all.
+The last year of the eighteenth century was also the last of
+the twenty-five years of partnership of Boulton &amp; Watt,
+and, with it, the patents under which that firm had held the
+great monopoly of steam-engine building expired. The
+right to manufacture the modern steam-engine was common
+to all. Watt had, at the commencement of the new century,<span class='pagenum'><a name="Page_146" id="Page_146">[146]</a></span>
+retired from active business-life. Boulton remained
+in business; but he was not the inventor of the new engine,
+and could not retain, by the exercise of all his remaining
+power, the privileges previously held by legal authorization.</p>
+
+<p>The young Boulton and the young Watt were not the
+Boulton &amp; Watt of earlier years; and, had they possessed
+all of the business talent and all of the inventive genius of
+their fathers, they could not have retained control of a business
+which was now growing far more rapidly than the facilities
+for manufacturing could be extended in any single establishment.
+All over the country, and even on the Continent
+of Europe, and in America, thousands of mechanics, and
+many men of mechanical tastes in other professions, were
+familiar with the principles of the new machine, and were
+speculating upon its value for all the purposes to which it
+has since been applied; and a multitude of enthusiastic mechanics,
+and a larger multitude of visionary and ignorant
+schemers, were experimenting with every imaginable device,
+in the vain hope of attaining perpetual motion, and other
+hardly less absurd results, by its modification and improvement.
+Steam-engine building establishments sprang up
+wherever a mechanic had succeeded in erecting a workshop
+and in acquiring a local reputation as a worker in metal,
+and many of Watt&#8217;s workmen went out from Soho to take
+charge of the work done in these shops. Nearly all of the
+great establishments which are to-day most noted for their
+extent and for the importance and magnitude of the work
+done in them, not only in Great Britain, but in Europe and
+the United States, came into existence during this second
+period of the application of the steam-engine as a prime
+mover.</p>
+
+<p>The new establishments usually grew out of older shops
+of a less pretentious character, and were managed by men
+who had been trained by Watt, or who had had a still more
+awakening experience with those who vainly strove to make<span class='pagenum'><a name="Page_147" id="Page_147">[147]</a></span>
+up, by their ingenuity and by great excellence of workmanship,
+the advantages possessed at Soho in a legal monopoly
+and greater experience in the business.</p>
+
+<p>It was exceedingly difficult to find expert and conscientious
+workmen, and machine-tools had not become as thoroughly
+perfected as had the steam-engine itself. These
+difficulties were gradually overcome, however, and thenceforward
+the growth of the business was increasingly rapid.</p>
+
+<p>Every important form of engine had now been invented.
+Watt had perfected, with the aid of Murdoch, both the
+pumping-engine and the rotative steam-engine for application
+to mills. He had invented the trunk engine, and Murdoch
+had devised the oscillating engine and the ordinary
+slide-valve, and had made a model locomotive-engine, while
+Hornblower had introduced the compound engine. The
+application of steam to navigation had been often proposed,
+and had sometimes been attempted, with sufficient success
+to indicate to the intelligent observer an ultimate triumph.
+It only remained to extend the use of steam as a motor into
+all known departments of industry, and to effect such improvements
+in details as experience should prove desirable.</p>
+
+<div class="figcenter"><a name="Fig41" id="Fig41"></a>
+<img src="images/illo175.png" alt="Leupold's Engine" width="251" height="400" />
+<p class="caption"><span class="smcap">Fig. 41.</span>&mdash;Leupold&#8217;s Engine, 1720.</p></div>
+
+<p>The engines of Hero, of Porta, and of Branca were, it
+will be remembered, non-condensing; but the first plan of a
+non-condensing engine that could be made of any really
+practical use is given in the &#8220;Theatrum Machinarum&#8221; of
+Leupold, published in 1720. This sketch is copied in <a href="#Fig41">Fig.
+41</a>. It is stated by Leupold that this plan was suggested
+by Papin. It consists of two single-acting cylinders, <i>r s</i>, receiving
+steam alternately from the same steam-pipe through
+a &#8220;four-way cock,&#8221; <i>x</i>, and exhausting into the atmosphere.
+Steam is furnished by the boiler, <i>a</i>, and the pistons, <i>c d</i>,
+are alternately raised and depressed, depressing and raising
+the pump-rods, <i>k l</i>, to which they are attached by the beams,
+<i>h g</i>, vibrating on the centres, <i>i i</i>. The water from the
+pumps, <i>o p</i>, is forced up the stand-pipe, <i>q</i>, and discharged
+at its top. The alternate action of the steam-pistons is secured<span class='pagenum'><a name="Page_148" id="Page_148">[148]</a></span>
+by turning the &#8220;four-way cock,&#8221; <i>x</i>, first into the position
+shown, and then, at the completion of the stroke, into
+the reverse position, by which change the steam from the
+boiler is then led into the cylinder, <i>s</i>, and the steam in <i>r</i> is
+discharged into the atmosphere.<a name="FNanchor_44_44" id="FNanchor_44_44"></a><a href="#Footnote_44_44" class="fnanchor">[44]</a></p>
+
+<p>Leupold states that he is indebted to Papin for the suggestion
+of the peculiar valve here used. He also proposed
+to use a Savery engine without condensation in raising
+water. We have no evidence that this engine was ever
+built.</p>
+
+<div class="figcenter"><a name="Fig42" id="Fig42"></a>
+<img src="images/illo176.png" alt="Newton's Steam-Carriage" width="350" height="178" />
+<p class="caption"><span class="smcap">Fig.</span> 42.&mdash;Newton&#8217;s Steam-Carriage, 1680.</p></div>
+
+<p>The first rude scheme for applying steam to locomotion
+on land was probably that of Isaac Newton, who, in 1680,
+proposed the machine shown in the accompanying figure
+(<a href="#Fig42">42</a>), which will be recognized as representing the scientific
+<span class='pagenum'><a name="Page_149" id="Page_149">[149]</a></span>
+toy which is found in nearly every collection of illustrative
+philosophical apparatus. As described in the &#8220;Explanation
+of the Newtonian Philosophy,&#8221; it consists of a spherical
+boiler, <i>B</i>, mounted on a carriage. Steam issuing from the
+pipe, <i>C</i>, seen pointing directly backward, by its reaction
+upon the carriage, drives the latter ahead. The driver, sitting
+at <i>A</i>, controls the steam by the handle, <i>E</i>, and cock,
+<i>F</i>. The fire is seen at <i>D</i>.</p>
+
+<p>When, at the end of the eighteenth century, the steam-engine
+had been so far perfected that the possibility of its
+successful application to locomotion had become fully and
+very generally recognized, the problem of adapting it to
+locomotion on land was attacked by many inventors.</p>
+
+<p>Dr. Robison had, as far back as in 1759, proposed it to
+James Watt during one of their conferences, at a time
+when the latter was even more ignorant than the former of
+the principles which were involved in the construction of the
+steam-engine, and this suggestion may have had some influence
+in determining Watt to pursue his research; thus setting
+in operation that train of thoughtful investigation and
+experiment which finally earned for him his splendid fame.</p>
+
+<p>In 1765, that singular genius, Dr. Erasmus Darwin,
+whose celebrity was acquired by speculations in poetry and
+philosophy as well as in medicine, urged Matthew Boulton&mdash;subsequently
+Watt&#8217;s partner, and just then corresponding
+with our own Franklin in relation to the use of steam-power&mdash;to
+construct a steam-carriage, or &#8220;fiery chariot,&#8221; as he<span class='pagenum'><a name="Page_150" id="Page_150">[150]</a></span>
+poetically styled it, and of which he sketched a set of plans.
+A young man named Edgeworth became interested in
+the scheme, and, in 1768, published a paper which had secured
+for him a gold medal from the Society of Arts. In
+this paper he proposed railroads on which the carriages
+were to be drawn by horses, <i>or by ropes from steam-winding
+engines</i>.</p>
+
+<div class="figcenter"><a name="Fig43" id="Fig43"></a>
+<img src="images/illo177.png" alt="Read's Steam Carriage" width="350" height="467" />
+<p class="caption"><span class="smcap">Fig. 43.</span>&mdash;Read&#8217;s Steam-Carriage, 1790.</p></div>
+
+<p><a name="Read" id="Read"></a>Nathan Read, of whom an account will be given hereafter,
+when describing his attempt to introduce steam-navigation,
+planned, and in 1790 obtained a patent for, a steam-carriage,
+of which the sketch seen in <a href="#Fig43">Fig. 43</a> is copied from
+the rough drawing accompanying his application. In the
+figure, <i>A A A A</i> are the wheels; <i>B B</i>, pinions on the hubs
+of the rear wheels, which are driven by a ratchet arrangement
+on the racks, <i>G G</i>, connected with the piston-rods;
+<i>C o</i> is the boiler; <i>D D</i>, the steam-pipes carrying steam to
+the steam-cylinder, <i>E E</i>; <i>F F</i> are the engine-frames; <i>H</i> is
+the &#8220;tongue&#8221; or &#8220;pole&#8221; of the carriage, and is turned by a
+horizontal steering-wheel, with which it is connected by
+the ropes or chains, <i>I K</i>, <i>I K</i>; <i>W W</i> are the cocks, which
+serve to shut off steam from the engine when necessary, and<span class='pagenum'><a name="Page_151" id="Page_151">[151]</a></span>
+to determine the amount of steam to be admitted. The
+pipes <i>a a</i> are exhaust-pipes, which the inventor proposed
+to turn so that they should point backward, in order to secure
+the advantage of the effort of reaction of the expelled
+steam. (!)</p>
+
+<p>Read made a model steam-carriage, which he exhibited
+when endeavoring to secure assistance in furtherance of his
+schemes, but seems to have given more attention to steam-navigation,
+and nothing was ever accomplished by him in
+this direction.</p>
+
+<div class="figcenter"><a name="Fig44" id="Fig44"></a>
+<img src="images/illo178.png" alt="Cugnot's Steam-Carriage" width="400" height="176" />
+<p class="caption"><span class="smcap">Fig. 44.</span>&mdash;Cugnot&#8217;s Steam-Carriage, 1770.</p></div>
+
+<p>These were merely promising schemes, however. The
+first actual experiment was made, as is supposed, by a
+French army-officer, <span class="smcap">Nicholas Joseph Cugnot</span>, who in
+1769 built a steam-carriage, which was set at work in presence
+of the French Minister of War, the Duke de Choiseul.
+The funds required by him were furnished by the Compte
+de Saxe. Encouraged by the partial success of the first
+locomotive, he, in 1770, constructed a second (<a href="#Fig44">Fig. 44</a>),
+which is still preserved in the Conservatoire des Arts et
+M&eacute;tiers, Paris.</p>
+
+<p>This machine, when recently examined by the author,
+was still in an excellent state of preservation. The carriage
+and its machinery are substantially built and well-finished,
+and exceedingly creditable pieces of work in every respect.
+It surprises the engineer to find such evidence of the high<span class='pagenum'><a name="Page_152" id="Page_152">[152]</a></span>
+character of the work of the mechanic Brezin a century ago.
+The steam-cylinders were 13 inches in diameter, and the
+engine was evidently of considerable power. This locomotive
+was intended for the transportation of artillery. It
+consists of two beams of heavy timber extending from end
+to end, supported by two strong wheels behind, and one still
+heavier but smaller wheel in front. The latter carries on
+its rim blocks which cut into the soil as the wheel turns,
+and thus give greater holding power. The single wheel is
+turned by two single-acting engines, one on each side, supplied
+with steam by a boiler (seen in the sketch) suspended
+in front of the machine. The connection between the engines
+and the wheels was effected by means of pawls, as
+first proposed by Papin, which could be reversed when it
+was desired to drive the machine backward. A seat is
+mounted on the carriage-body for the driver, who steers the
+machine by a train of gearing, which turns the whole frame,
+carrying the machinery 15 or 20 degrees either way. This
+locomotive was found to have been built on a tolerably satisfactory
+general plan; but the boiler was too small, and
+the steering apparatus was incapable of handling the carriage
+with promptness.</p>
+
+<p>The death of one of Cugnot&#8217;s patrons, and the exile of
+the other, put an end to Cugnot&#8217;s experiments.</p>
+
+<p>Cugnot was a mechanic by choice, and exhibited great
+talent. He was a native of Vaud, in Lorraine, where he
+was born in 1725. He served both in the French and the
+German armies. While under the Mar&eacute;chal de Saxe, he
+constructed his first steam locomotive-engine, which only
+disappointed him, as he stated, in consequence of the inefficiency
+of the feed-pumps. The second was that built under
+the authority of the Minister Choiseul, and cost 20,000
+livres. Cugnot received from the French Government a
+pension of 600 livres. He died in 1804, at the age of seventy-nine
+years.</p>
+
+<div class="figcenter"><a name="Fig45" id="Fig45"></a>
+<img src="images/illo180.png" alt="Murdoch's Model" width="404" height="350" />
+<p class="caption"><span class="smcap">Fig. 45.</span>&mdash;Murdoch&#8217;s Model, 1784.</p></div>
+
+<p>Watt, at a very early period, proposed to apply his own<span class='pagenum'><a name="Page_153" id="Page_153">[153]</a></span>
+engine to locomotion, and contemplated using either a non-condensing
+engine or an air-surface condenser. He actually
+included the locomotive-engine in his patent of 1784; and
+his assistant, Murdoch, in the same year, made a working-model
+locomotive (<a href="#Fig45">Fig. 45</a>), which was capable of running
+at a rapid rate. This model, now deposited in the Patent
+Museum at South Kensington, London, had a flue-boiler,
+and its steam-cylinder was three-fourths of an inch in diameter,
+and the stroke of piston 2 inches. The driving-wheels
+were 9<span class="enum">1</span>&#8725;<span class="denom">2</span> inches diameter.</p>
+
+<p>Nothing was, however, done on a larger scale by either
+Watt or Murdoch, who both found more than enough to
+claim their attention in the construction and introduction
+of other engines. Murdoch&#8217;s model is said to have run
+from 6 to 8 miles an hour, its little driving-wheels making
+from 200 to 275 revolutions per minute. As is seen in the
+sketch, this model was fitted with the same form of engine,
+known as the &#8220;grasshopper-engine,&#8221; which was used in the
+United States by Oliver Evans.</p>
+
+<p>&#8220;To Oliver Evans,&#8221; says Dr. Ernest Alban, the distinguished
+German engineer, &#8220;was it reserved to show the true
+value of a long-known principle, and to establish thereon a
+new and more simple method of applying the power of
+steam&mdash;a method that will remain an eternal memorial to<span class='pagenum'><a name="Page_154" id="Page_154">[154]</a></span>
+its introducer.&#8221; Dr. Alban here refers to the earliest permanently
+successful introduction of the non-condensing
+high-pressure steam-engine.</p>
+
+<div class="figcenter"><a name="Port6" id="Port6"></a>
+<img src="images/illo181.png" alt="Evans" width="350" height="444" />
+<p class="caption">Oliver Evans.</p></div>
+
+<p><span class="smcap"><a href="#Port6">Oliver Evans</a></span>, one of the most ingenious mechanics
+that America has ever produced, was born at Newport,
+Del., in 1755 or 1756, the son of people in very humble
+circumstances.</p>
+
+<p>He was, in his youth, apprenticed to a wheelwright, and
+soon exhibited great mechanical talent and a strong desire
+to acquire knowledge. His attention was, at an early period,
+drawn to the possible application of the power of
+steam to useful purposes by the boyish pranks of one of his
+comrades, who, placing a small quantity of water in a gun-barrel,
+and ramming down a tight wad, put the barrel in
+the fire of a blacksmith&#8217;s forge. The loud report which<span class='pagenum'><a name="Page_155" id="Page_155">[155]</a></span>
+accompanied the expulsion of the wad was an evidence to
+young Evans of great and (as he supposed) previously undiscovered
+power.</p>
+
+<p>Subsequently meeting with a description of a Newcomen
+engine, he at once noticed that the elastic force of confined
+steam was not there utilized. He then designed the non-condensing
+engine, in which the power was derived exclusively
+from the tension of high-pressure steam, and proposed
+its application to the propulsion of carriages.</p>
+
+<p>About the year 1780, Evans joined his brothers, who
+were millers by occupation, and at once employed his inventive
+talent in improving the details of mill-work, and
+with such success as to reduce the cost of attendance one-half,
+and also to increase the fineness of the flour made. He
+proved himself a very expert millwright.</p>
+
+<p>In 1786 he applied to the Pennsylvania Legislature for
+a patent for the application of the steam-engine to driving
+mills, and to the steam-carriage, but was refused it. In 1800
+or 1801, Evans, after consultation with Professor Robert
+Patterson, of the University of Pennsylvania, and getting
+his approval of the plans, commenced the construction of a
+steam-carriage to be driven by a non-condensing engine.
+He soon concluded, however, that it would be a better
+scheme, pecuniarily, to adapt his engine, which was novel
+in form and of small first cost, to driving mills; and he
+accordingly changed his plans, and built an engine of 6
+inches diameter of cylinder and 18 inches stroke of piston,
+which he applied with perfect success to driving a plaster-mill.</p>
+
+<div class="figcenter"><a name="Fig46" id="Fig46"></a>
+<img src="images/illo183.png" alt="Evans's Non-Condensing Engine" width="600" height="339" />
+<p class="caption"><span class="smcap">Fig. 46.</span>&mdash;Evans&#8217;s Non-condensing Engine, 1800.</p></div>
+
+<p>This engine, which he called the &#8220;Columbian Engine,&#8221;
+was of a peculiar form, as seen in <a href="#Fig46">Fig. 46</a>. The beam is supported
+at one end by a rocking column; at the other, it is
+attached directly to the piston-rod, while the crank lies beneath
+the beam, the connecting-rod, 1, being attached to
+the latter at the extreme end. The head of the piston-rod is
+compelled to rise and fall in a vertical line by the &#8220;Evans&#8217;s<span class='pagenum'><a name="Page_156" id="Page_156">[156]</a></span>
+parallelogram&#8221;&mdash;a kind of parallel-motion very similar to
+one of those designed by Watt. In the sketch (<a href="#Fig46">Fig. 46</a>), 2
+is the crank, 3 the valve-motion, 4 the steam-pipe from the
+boiler, <i>E</i>, 5 6 7 the feed-pipe leading from the pump, <i>F</i>.
+<i>A</i> is the boiler. The flame from the fire on the grate, <i>H</i>,
+passes under the boiler between brick walls, and back
+through a central flue to the chimney, <i>I</i>.</p>
+
+<p>Subsequently, Evans continued to extend the applications
+of his engine and to perfect its details; and, others
+following in his track, the non-condensing engine is to-day
+fulfilling the predictions which he made 70 years ago, when
+he said:</p>
+
+<p>&#8220;I have no doubt that my engines will propel boats
+against the current of the Mississippi, and wagons on turnpike
+roads, with great profit....&#8221;</p>
+
+<p>&#8220;The time will come when people will travel in stages
+moved by steam-engines from one city to another, almost
+as fast as birds can fly, 15 or 20 miles an hour.... A carriage
+will start from Washington in the morning, the passengers
+will breakfast at Baltimore, dine at Philadelphia,
+and sup in New York the same day....</p>
+
+<p>&#8220;Engines will drive boats 10 or 12 miles an hour, and<span class='pagenum'><a name="Page_157" id="Page_157">[157]</a></span>
+there will be hundreds of steamers running on the Mississippi,
+as predicted years ago.&#8221;<a name="FNanchor_45_45" id="FNanchor_45_45"></a><a href="#Footnote_45_45" class="fnanchor">[45]</a></p>
+
+<div class="figcenter"><a name="Fig47" id="Fig47"></a>
+<img src="images/illo184.png" alt="Oruktor Amphibolis" width="400" height="251" />
+<p class="caption"><span class="smcap">Fig. 47.</span>&mdash;Evans&#8217;s &#8220;Oruktor Amphibolis,&#8221; 1804.</p></div>
+
+<p>In 1804, Evans applied one of his engines in the transportation
+of a large flat-bottomed craft, built on an order
+of the Board of Health of Philadelphia, for use in clearing
+some of the docks along the water-front of the city. Mounting
+it on wheels, he placed in it one of his 5-horse power
+engines, and named the odd machine (<a href="#Fig47">Fig. 47</a>) &#8220;Oruktor
+Amphibolis.&#8221; This steam dredging-machine, weighing
+about 40,000 pounds, was then propelled very slowly from
+the works, up Market Street, around to the Water-Works, and
+then launched into the Schuylkill. The engine was then
+applied to the paddle-wheel at the stern, and drove the
+craft down the river to its confluence with the Delaware.</p>
+
+<p>In September of the same year, Evans laid before the
+Lancaster Turnpike Company a statement of the estimated
+expenses and profits of steam-transportation on the common
+road, assuming the size of the carriage used to be sufficient
+for transporting 100 barrels of flour 50 miles in 24 hours,<span class='pagenum'><a name="Page_158" id="Page_158">[158]</a></span>
+and placed in competition with 10 wagons drawn by 5
+horses each.</p>
+
+<p>In the <a href="#Fig47">sketch</a> above given of the &#8220;Oruktor Amphibolis,&#8221;
+the engine is seen to resemble that previously described.
+The wheel, <i>A</i>, is driven by a rod depending from the end
+of a beam, <i>B&#8242; B</i>, the other end of which is supported at <i>E</i>
+by the frame, <i>E F G</i>. The body of the machine is carried
+on wheels, <i>K K</i>, driven by belts, <i>M M</i>, from the pulley on
+the shaft carrying <i>A</i>. The paddle-wheel is seen at <i>W</i>.
+Evans had some time previously sent Joseph Sampson to
+England with copies of his plans, and by him they were
+shown to Trevithick, Vivian, and other British engineers.</p>
+
+<p>Among other devices, the now familiar Cornish boiler,
+having a single internal flue, and the Lancashire boiler,
+having a pair of internal flues, were planned and used by
+Evans.</p>
+
+<p>At about the time that he was engaged on his steam
+dredging-machine, Evans communicated with Messrs. McKeever
+&amp; Valcourt, who contracted with him to build an
+engine for a steam-vessel to ply between New Orleans and
+Natchez on the Mississippi, the hull of the vessel to be built
+on the river, and the machinery to be sent to the first-named
+city to be set up in the boat. Financial difficulties
+and low water combined to prevent the completion of the
+steamer, and the engine was set at work driving a saw-mill,
+where, until the mill was destroyed by fire, it sawed lumber
+at the rate of 250 feet of boards per hour.</p>
+
+<p>Evans never succeeded in accomplishing in America as
+great a success as had rewarded Watt in Great Britain; but
+he continued to build steam-engines to the end of his life,
+April 19, 1819, and was succeeded by his sons-in-law, James
+Rush and David Muhlenberg.</p>
+
+<p>He exhibited equal intelligence and ingenuity in perfecting
+the processes of milling, and in effecting improvements
+in his own business, that of the millwright. When but
+twenty-four years old, he invented a machine for making<span class='pagenum'><a name="Page_159" id="Page_159">[159]</a></span>
+the wire teeth used in cotton and woolen cards, turning
+them out at the rate of 3,000 per minute. A little later he
+invented a card-setting machine, which cut the wire from
+the reel, bent the teeth, and inserted them. In milling, he
+invented a whole series of machines and attachments, including
+the elevator, the &#8220;conveyor,&#8221; the &#8220;hopper-box,&#8221; the
+&#8220;drill,&#8221; and the &#8220;descender,&#8221; and enabled the miller to
+make finer flour, gaining over 20 pounds to the barrel, and
+to do this at half the former cost of attendance. The introduction
+of his improvements into Ellicott&#8217;s mills, near
+Baltimore, where 325 barrels of flour were made per day,
+was calculated to have saved nearly $5,000 per year in cost
+of labor, and over $30,000 by increasing the production.
+He wrote &#8220;The Young Steam-Engineer&#8217;s Guide,&#8221; and a
+work which remained standard many years after his death,
+&#8220;The Young Millwright&#8217;s Guide.&#8221; Less fortunate than his
+transatlantic rival, he was nevertheless equally deserving
+of fame. He has sometimes been called &#8220;The Watt of
+America.&#8221;</p>
+
+<p>The application of steam to locomotion on the common
+road was much more successful in Great Britain than in the
+United States. As early as 1786, William Symmington,
+subsequently more successful in his efforts to introduce
+steam for marine propulsion, assisted by his father, made a
+working model of a steam-carriage, which did not, however,
+lead to important results.</p>
+
+<p>In 1802, Richard Trevithick, a pupil of Murdoch&#8217;s, who
+afterward became well known in connection with the introduction
+of railroads, made a model steam-carriage, which
+was patented in the same year. The model may still be
+seen in the Patent Museum at South Kensington.<a name="FNanchor_46_46" id="FNanchor_46_46"></a><a
+href="#Footnote_46_46" class="fnanchor">[46]</a></p>
+
+<p>In this engine, high-pressure steam was employed, and
+the condenser was dispensed with. The boiler was of the
+form devised by Evans, and was subsequently generally<span class='pagenum'><a name="Page_160" id="Page_160">[160]</a></span>
+used in Cornwall, where it was called the &#8220;Trevithick
+Boiler.&#8221; The engine had but one cylinder, and the piston-rod
+drove a &#8220;cross-tail,&#8221; working in guides, which was connected
+with a &#8220;cross-head&#8221; on the opposite side of the shaft
+by two &#8220;side-rods.&#8221; The connecting-rod was attached to
+the cross-head and the crank, &#8220;returning&#8221; toward the cylinder
+as the shaft lay between the latter and the cross-head.
+This was probably the first example of the now common
+&#8220;return connecting-rod engine.&#8221; The connection between
+the crank-shaft and the wheels of the carriage was effected
+by gearing. The valve-gear and the feed-pumps were
+worked from the engine-shaft. The inventor proposed to
+secure his wheels against slipping by projecting bolts, when
+necessary, through the rim of the wheel into the ground.
+The first carriage of full size was built by Trevithick and
+Vivian at Camborne, in 1803, and, after trial, was taken to
+London, where it was exhibited to the public. <i>En route</i>,
+it was driven by its own engines to Plymouth, 90 miles
+from Camborne, and then shipped by water. It is not
+known whether the inventor lost faith in his invention; but
+he very soon dismantled the machine, sold the engine and
+carriage separately, and returned to Cornwall, where he
+soon began work on a railroad-locomotive.</p>
+
+<p>In 1821, Julius Griffiths, of Brompton, Middlesex, England,
+patented a steam-carriage for the transportation of
+passengers on the highway. His first road-locomotive was
+built in the same year by Joseph Bramah, one of the ablest
+mechanics of his time. The frame of the carriage carried a
+large double coach-body between the two axles, and the
+machinery was mounted over and behind the rear axle.
+One man was stationed on a rear platform, to manage the
+engine and to attend to the fire, and another, stationed in
+front of the body of the coach, handled the steering-wheel.
+The boiler was composed of horizontal water-tubes and
+steam-tubes, the latter being so situated as to receive heat
+from the furnace-gases <i>en route</i> to the chimney, and thus to<span class='pagenum'><a name="Page_161" id="Page_161">[161]</a></span>
+act as a superheater. The wheels were driven, by means
+of intermediate gearing, by two steam-engines, which, with
+their attachments, were suspended on helical springs, to
+prevent injury by jars and shocks. An air-surface condenser
+was used, consisting of flattened thin metal tubes,
+cooled by the contact of the external air, and discharging
+the water of condensation, as it accumulated within them,
+into a feed-pump, which, in turn, forced it into the lowest
+row of tubes in the boiler.</p>
+
+<p>The boiler did not prove large enough for continuous
+work; but the carriage was used experimentally, now and
+then, for a number of years.</p>
+
+<p>During the succeeding ten years the adaptation of the
+steam-engine to land-transportation continued to attract
+more and more attention, and experimental road-engines
+were built with steadily-increasing frequency. The defects
+of these engines revealing themselves on trial, they were
+one by one remedied, and the road-locomotive gradually
+assumed a shape which was mechanically satisfactory. Their
+final introduction into general use seemed at one time only
+a matter of time; their non-success was due to causes over
+which the legislator and the general public, and not the engineer,
+had control, as well as to the development of steam-transportation
+on a rival plan.</p>
+
+<p>In 1822, David Gordon patented a road-engine, but it
+is not known whether it was ever built. At about the same
+time, Mr. Goldsworthy Gurney, who subsequently took an
+active part in their introduction, stated, in his lectures, that
+&#8220;elementary power is capable of being applied to propel
+carriages along common roads with great political advantage,
+and the floating knowledge of the day places the object
+within reach.&#8221; He made an ammonia-engine&mdash;probably
+the first ever made&mdash;and worked it so successfully, that
+he made use of it in driving a little locomotive.</p>
+
+<p>Two years later, Gordon patented a curious arrangement,
+which, however, had been proposed twelve years earlier by<span class='pagenum'><a name="Page_162" id="Page_162">[162]</a></span>
+Brunton, and was again proposed afterward by Gurney, and
+others. This consisted in fitting to the engine a set of
+jointed legs, imitating, as nearly as the inventor could make
+them, the action of a horse&#8217;s legs and feet. Such an arrangement
+was actually experimented with until it was
+found that they could not be made to work satisfactorily,
+when it was also found that they were not needed.</p>
+
+<p>During the same season, Burstall &amp; Hill made a steam-carriage,
+and made many unsuccessful attempts to introduce
+their plan. The engine used was like that of Evans, except
+that the steam-cylinder was placed at the end of the
+beam, and the crank-shaft under the middle. The front
+and rear wheels were connected by a longitudinal shaft and
+bevel gearing. The boiler was found to have the usual defect,
+and would only supply steam for a speed of three or
+four miles an hour. The result was a costly failure. W.
+H. James, of London, in 1824-&#8217;25, proposed several devices
+for placing the working parts, as well as the body of the
+carriage, on springs, without interfering with their operation,
+and the Messrs. Seaward patented similar devices.
+Samuel Brown, in 1826, introduced a gas-engine, in which
+the piston was driven by the pressure produced by the
+combustion of gas, and a vacuum was secured by the condensation
+of the resulting vapor. Brown built a locomotive
+which he propelled by this engine. He ascended Shooter&#8217;s
+Hill, near London, and the principal cause of his ultimate
+failure seems to have been the cost of operating the engine.</p>
+
+<p>From this date forward, during several years, a number
+of inventors and mechanics seem to have devoted their
+whole time to this promising scheme. Among them, Burstall
+&amp; Hill, Gurney, Ogle &amp; Summers, Sir Charles Dance,
+and Walter Hancock, were most successful.</p>
+
+<p>Gurney, in the year 1827, built a steam-carriage, which
+he kept at work nearly two years in and about London, and
+sometimes making long journeys. On one occasion he made
+the journey from Meksham to Cranford Bridge, a distance<span class='pagenum'><a name="Page_163" id="Page_163">[163]</a></span>
+of 85 miles, in 10 hours, including all stops. He used the
+mechanical legs previously adopted by Brunton and by
+Gordon, but omitted this rude device in those engines subsequently
+built.</p>
+
+<p>Gurney&#8217;s engine of 1828 is of interest to the engineer as
+exhibiting a very excellent arrangement of machinery, and
+as having one of the earliest of &#8220;sectional boilers.&#8221; The
+latter was of peculiar form, and differed greatly in design
+from the sectional boiler invented a quarter of a century
+earlier by John Stevens, in the United States.</p>
+
+<div class="figcenter"><a name="Fig48" id="Fig48"></a>
+<img src="images/illo190.png" alt="Gurney's Steam-Carriage" width="500" height="240" />
+<p class="caption"><span class="smcap">Fig. 48.</span>&mdash;Gurney&#8217;s Steam-Carriage.</p>
+<p class="center fsize80"><a href="images/large190.png">Large scale image</a> (241 kB).</p></div>
+
+<p>In the sketch (<a href="#Fig48">Fig. 48</a>) this boiler is seen at the right.
+It was composed of bent <span class="fsize125"><b>&#9665;</b></span>-shaped tubes, <i>a a</i>, connected to
+two cylinders, <i>b b</i>, the upper one of which was a steam-chamber.
+Vertical tubes connected these two chambers,
+and permitted a complete and regular circulation of the
+water. A separate reservoir, called a separator, <i>d</i>, was connected
+with these chambers by pipes, as shown. From the
+top of this separator a steam-pipe, <i>e e e</i>, conveyed steam to the
+engine-cylinders at <i>f</i>. The cranks, <i>g</i>, on the rear axle were
+turned by the engines, and the eccentric, <i>h</i>, on the axle drove
+the valve-gearing and the valve, <i>i</i>. The link, <i>k l</i>, being
+moved by a line, <i>l l</i>, led from the driver&#8217;s seat, the carriage
+was started, stopped, or reversed, by throwing the upper end<span class='pagenum'><a name="Page_164" id="Page_164">[164]</a></span>
+of the link into gear with the valve-stem, by setting the
+link midway between its upper and lower positions, or by
+raising it until the lower end, coming into action on the
+valve-stem, produced a reverse motion of the valve. The
+pin on which this link vibrated is seen at the centre of its
+elliptical strap. The throttle-valve, <i>o</i>, by which the supply
+of steam to the engine was adjusted, was worked by the lever,
+<i>n</i>. The exhaust-pipe, <i>p</i>, led to the tank, <i>q</i>, and the uncondensed
+vapor passed to the chimney, <i>s s</i>, by the pipe, <i>r r</i>.
+The force-pump, <i>u</i>, taking feed-water from the tank, <i>t</i>, supplied
+it to the boiler by the pipe, <i>x x x</i>, which, <i>en route</i>, was
+coiled up to form a &#8220;heater&#8221; directly above the boiler. The
+supply was regulated by the cock, <i>y</i>. The attendant had a
+seat at <i>z</i>. A blast-apparatus, 1, was driven by an independent
+engine, 2 3, and produced a forced blast, which was
+led to the boiler-furnace through the air-duct, 5 5; 4 4 represents
+the steam-pipe to the little blowing-engine. The
+steering-wheel, 6, was directed by a lever, 7, and the change
+of direction of the perch, 8, which turned about a king-bolt
+at 9, gave the desired direction to the forward wheels and
+to the carriage.</p>
+
+<p>This seems to have been one of the best designs brought
+out at that time. The boiler, built to carry 70 pounds, was
+safe and strong, and was tested up to 800 pounds pressure.
+A forced draught was provided. The engines were well
+placed, and of good design. The valve was arranged to
+work the steam with expansion from half-stroke. The feed-water
+was heated, and the steam slightly superheated. The
+boiler here used has been since reproduced under new names
+by later inventors, and is still used with satisfactory results.
+Modifications of the &#8220;pipe-boiler&#8221; were made by several
+other makers of steam-carriages also. Anderson &amp; James
+made their boilers of lap-welded iron tubes of one inch internal
+diameter and one-fifth inch thick, and claimed for
+them perfect safety. Such tubes should have sufficient
+strength to sustain a pressure of 20,000 pounds per square<span class='pagenum'><a name="Page_165" id="Page_165">[165]</a></span>
+inch. If made of such good iron as the makers claimed to
+have put into them, &#8220;which worked like lead,&#8221; they would,
+as was also claimed, when ruptured, open by tearing, and
+discharge their contents without producing the usual disastrous
+consequences of boiler explosions.</p>
+
+<p>The primary principle of the sectional boiler was then
+well understood. The boilers of Ogle &amp; Summers were
+made up of pairs of upright tubes, set one within the other,
+the intervening space being filled with water and steam, and
+the flame passing through the inner and around the outer
+tube of each pair.</p>
+
+<p>One of the engines of Sir James Anderson and W. H.
+James was built in 1829. It had two 3<span class="enum">1</span>&#8725;<span class="denom">2</span>-inch steam-cylinders,
+driving the rear wheels independently. In James&#8217;s
+earlier plan of 1824-&#8217;25, a pair of cylinders was attached to
+each of the two halves into which the rear axle was divided,
+and were arranged to drive cranks set at right-angles with
+each other. The later machine weighed 3 tons, and carried
+15 passengers, on a rough graveled road across the Epping
+Forest, at the rate of from 12 to 15 miles per hour. Steam
+was carried at 300 pounds. Several tubes gave way in the
+welds, but the carriage returned, carrying 24 passengers at
+the rate of 7 miles per hour. On a later trial, with new
+boilers, the carriage again made 15 miles per hour. It was,
+however, subject to frequent accidents, and was finally
+withdrawn.</p>
+
+<p><span class="smcap">Walter Hancock</span> was the most successful and persevering
+of all those who attempted the introduction of steam
+on the common road. He had, in 1827, patented a boiler
+of such peculiar form, that it deserves description. It consisted
+of a collection of flat chambers, of which the walls
+were of boiler-plate. These chambers were arranged side
+by side, and connected laterally by tubes and stays, and all
+were connected by short vertical tubes to a horizontal large
+pipe placed across the top of the boiler-casing, and serving
+as a steam-drum or separator. This earliest of &#8220;sheet flue-boilers&#8221;<span class='pagenum'><a name="Page_166" id="Page_166">[166]</a></span>
+did excellent service on Hancock&#8217;s steam-carriages,
+where experience showed that there was little or no danger
+of disruptive explosions.</p>
+
+<p>Hancock&#8217;s first steam-carriage was mounted on three
+wheels, the leading-wheel arranged to swivel on a king-bolt,
+and driven by a pair of oscillating cylinders connected with
+its axle, which was &#8220;cranked&#8221; for the purpose. The engines
+turned with the steering-wheel. This carriage was
+by no means satisfactory, but it was used for a long time,
+and traveled many hundreds of miles without once failing
+to do the work assigned it.</p>
+
+<p>By this time there were a half-dozen steam-carriages
+under construction for Hancock, for Ogle &amp; Summers, and
+for Sir Charles Dance.</p>
+
+<p>In 1831, Hancock placed a new carriage on a route between
+London and Stratford, where it ran regularly for
+hire. Dance, in the same season, started another on the
+line between Cheltenham and Gloucester, where it ran from
+February 21st to June 22d, traveling 3,500 miles and carrying
+3,000 passengers, running the 9 miles in 55 minutes
+usually, and sometimes in three-quarters of an hour, and
+never meeting with an accident, except the breakage of an
+axle in running over heaps of stones which had been purposely
+placed on the road by enemies of the new system of
+transportation. Ogle &amp; Summers&#8217;s carriage attained a
+speed, as testified by Ogle before a committee of the House
+of Commons, of from 32 to 35 miles an hour, and on a rising
+grade, near Southampton, at 24<span class="enum">1</span>&#8725;<span class="denom">2</span> miles per hour. They
+carried 250 pounds of steam, ran 800 miles, and met with
+no accident. Colonel Macerone, in 1833, ran a steam-carriage
+of his own design from London to Windsor and back,
+with 11 passengers, a distance of 23<span class="enum">1</span>&#8725;<span class="denom">2</span> miles, in 2 hours. Sir
+Charles Dance, in the same year, ran his carriage 16 miles
+an hour, and made long excursions at the rate of 9 miles an
+hour. Still another experimenter, Heaton, ascended Lickey
+Hill, between Worcester and Birmingham, on gradients of<span class='pagenum'><a name="Page_167" id="Page_167">[167]</a></span>
+one in eight and one in nine, in places; this was considered
+one of the worst pieces of road in England. The carriage
+towed a coach containing 20 passengers.</p>
+
+<p>Of all these, and many others, Hancock, however, had
+most marked success. His coach, called the &#8220;Infant,&#8221;
+which was set at work in February, 1831, was, a year later,
+plying between London &#8220;City&#8221; and Paddington. Another,
+called the &#8220;Era,&#8221; was built for the London and Greenwich
+Steam-Carriage Company, which was mechanically a success.
+The company, however, was financially unsuccessful.
+In October, 1832, the &#8220;Infant&#8221; ran to Brighton from London,
+carrying a party of 11, at the rate of 9 miles per hour,
+ascending Redhill at a speed of 5 miles. They steamed 38
+miles the first day, stopping at night at Hazledean, and
+reached Brighton next day, running 11 miles per hour.
+Returning with 15 passengers, the coach ran 1 mile in less
+than 4 minutes, and made 10 miles in 55 minutes. A run
+from Stratford to Brighton was made in less than 10 hours,
+at an average speed of 12 miles an hour running time, the
+actual running time being less than 6 hours. The next
+year another carriage, the &#8220;Enterprise,&#8221; was put on the
+road to Paddington by Hancock for another company, and
+ran regularly over two weeks; but this company was also
+unsuccessful. In the summer of 1833 he brought out still
+another steam-coach, the &#8220;Autopsy&#8221; (<a href="#Fig49">Fig. 49</a>), which he
+ran to Brighton, and then, returning to London, man&oelig;uvred
+the carriage in the crowded streets without difficulty or accident.
+He went about the streets of London at all times,
+and without hesitation. The coach next ran between Finsbury
+Square and Pentonville regularly for four weeks, without
+accident or delay. In the sketch, a part of the side is
+broken away to show the machinery. The boiler, <i>A B</i>,
+supplies steam through the steam-pipe, <i>H K</i>, to the steam-engine,
+<i>C D</i>, which is coupled to the crank-shaft, <i>F</i>. <i>E</i> is
+the feed-pump. The rear axle is turned by the endless
+chain seen connecting it with the engine-shaft, and the rear<span class='pagenum'><a name="Page_168" id="Page_168">[168]</a></span>
+wheels, <i>S</i>, are thus driven. A blower, <i>T</i>, gives a forced
+draught. The driver sits at <i>M</i>, steering by the wheel, <i>N</i>,
+which is coupled to the larger wheel, <i>P</i>, and thus turns the
+forward axle into any desired position. In 1834, Hancock
+built a steam &#8220;drag&#8221; on an Austrian order, which, carrying
+10 persons and towing a coach containing 6 passengers,
+was driven through the city beyond Islington, making 14
+miles an hour on a level, and 8 miles or more on rising
+ground. In the same year he built the &#8220;Era,&#8221; and, in August,
+put the &#8220;Autopsy&#8221; on with it, to make a steam-line
+to Paddington. These coaches ran until the end of November,
+carrying 4,000 passengers, at a usual rate of speed of
+12 miles per hour. He then sent the &#8220;Era&#8221; to Dublin,
+where, on one occasion, it ran 18 miles per hour.</p>
+
+<div class="figcenter"><a name="Fig49" id="Fig49"></a>
+<img src="images/illo195.png" alt="Hancock's Autopsy" width="400" height="183" />
+<p class="caption"><span class="smcap">Fig. 49.</span>&mdash;Hancock&#8217;s &#8220;Autopsy,&#8221; 1833.</p></div>
+
+<p>In 1835 a large carriage, the &#8220;Erin,&#8221; was completed,
+which was intended to carry 20 passengers. It towed three
+omnibuses and a stage-coach, with 50 passengers, on a level
+road, at the speed of 10 miles an hour. It drew an omnibus
+with 18 passengers through Whitehall, Charing Cross, and
+Regent Street, and out to Brentford, running 14 miles an
+hour. It ran also to Reading, making 38 miles, with the
+same load, in 3 hours and 8 minutes running time. The
+stops <i>en route</i> occupied a half-hour. The same carriage
+made 75 miles to Marlborough in 7<span class="enum">1</span>&#8725;<span class="denom">2</span>
+hours running time,<span class='pagenum'><a name="Page_169" id="Page_169">[169]</a></span>
+stopping 4<span class="enum">1</span>&#8725;<span class="denom">2</span> hours on the road, in consequence of having
+left the tender and supplies behind.</p>
+
+<p>In May, 1836, Hancock put all his carriages on the Paddington
+road, and ran regularly for over five months, running
+4,200 miles in 525 trips to Islington, 143 to Paddington,
+and 44 to Stratford, passing through the city over 200
+times. The carriages averaged 5 hours and 17 or 18 minutes
+daily running time. A light steam-phaeton, built in 1838,
+for his own use, made 20 miles an hour, and was driven
+about the city, and among horses and carriages, without
+causing annoyance or danger. Its usual speed was about
+10 miles an hour. Altogether, Hancock built nine steam-carriages,
+capable of carrying 116 passengers in addition
+to the regular attendants.<a name="FNanchor_47_47" id="FNanchor_47_47"></a><a href="#Footnote_47_47" class="fnanchor">[47]</a></p>
+
+<p>In December, 1833, about 20 steam-carriages and traction
+road-engines were running, or were in course of construction,
+in and near London. In our own country, the
+roughness of roads discouraged inventors; and in Great
+Britain even, the successful introduction of road-locomotives,
+which seemed at one time almost an accomplished
+fact, finally met with so many obstacles, that even Hancock,
+the most ingenious, persistent, and successful constructor,
+gave up in despair. Hostile legislation procured by opposing
+interests, and the rapid progress of steam-locomotion on
+railroads, caused this result.</p>
+
+<p>In consequence of this interruption of experiment, almost
+nothing was done during the succeeding quarter of a
+century, and it is only within a few years that anything like
+a business success has been founded upon the construction
+of road-locomotives, although the scheme seems to have
+been at no time entirely given up.</p>
+
+<p>The opposition of coach-proprietors, and of all classes
+having an interest in the old lines of coaches, was most determined,<span class='pagenum'><a name="Page_170" id="Page_170">[170]</a></span>
+and the feeling evinced by them was intensely
+bitter; but the advocates of the new system of transportation
+were equally determined and persevering, and, having
+right on their side, and the pecuniary advantage of the
+public as their object, they would probably have succeeded
+ultimately, except for the introduction of the still better
+method of transportation by rail.</p>
+
+<p>In the summer of 1831, when the war between the two
+parties was at its height, a committee of the British House
+of Commons made a very complete investigation of the
+subject. This committee reported that they had become
+convinced that &#8220;the substitution of inanimate for animal
+power, in draught on common roads, is one of the most important
+improvements in the means of internal communication
+ever introduced.&#8221; They considered its practicability
+to have been &#8220;fully established,&#8221; and predicted that its
+introduction would &#8220;take place more or less rapidly, in proportion
+as the attention of scientific men shall be drawn, by
+public encouragement, to further improvement.&#8221; The success
+of the system had, as they stated, been retarded by
+prejudice, adverse interests, and prohibitory tolls; and the
+committee remark: &#8220;When we consider that these trials
+have been made under the most unfavorable circumstances,
+at great expense, in total uncertainty, without any of those
+guides which experience has given to other branches of engineering;
+that those engaged in making them are persons
+looking solely to their own interests, and not theorists
+attempting the perfection of ingenious models; when we
+find them convinced, after long experience, that they are
+introducing such a mode of conveyance as shall tempt the
+public, by its superior advantages, from the use of the
+admirable lines of coaches which have been generally established,
+it surely cannot be contended that the introduction
+of steam-carriages on common roads is, as yet, an uncertain
+experiment, unworthy of legislative attention.&#8221;</p>
+
+<p>Farey, one of the most distinguished mechanical engineers<span class='pagenum'><a name="Page_171" id="Page_171">[171]</a></span>
+of the time, testified that he considered the practicability
+of such a system as fully established, and that the result
+would be its general adoption. Gurney had run his carriage
+between 20 and 30 miles an hour; Hancock could sustain a
+speed of 10 miles; Ogle had run his coach 32 to 35 miles
+an hour, and ascended a hill rising 1 in 6 at the speed of
+24<span class="enum">1</span>&#8725;<span class="denom">2</span> miles. Summers had traveled up a hill having a gradient
+of 1 in 12, with 19 passengers, at the rate of speed of
+15 miles per hour; he had run 4<span class="enum">1</span>&#8725;<span class="denom">2</span> hours at 30 miles an hour.
+Farey thought that steam-coaches would be found to cost
+one-third as much as the stage-coaches in use. The steam-carriages
+were reported to be safer than those drawn by
+horses, and far more manageable; and the construction of
+boilers adopted&mdash;the &#8220;sectional&#8221; boiler, as it is now called&mdash;completely
+insured against injury by explosion, and the
+dangers and inconveniences arising from the frightening of
+horses had proved to be largely imaginary. The wear and
+tear of roads were found to be less than with horses, while
+with broad wheel-tires the carriages acted beneficially as
+road-rollers. The committee finally concluded:</p>
+
+<p>&#8220;1. That carriages can be propelled by steam on common
+roads at an average rate of 10 miles per hour.</p>
+
+<p>&#8220;2. That at this rate they have conveyed upward of 14
+passengers.</p>
+
+<p>&#8220;3. That their weight, including engine, fuel, water,
+and attendants, may be under three tons.</p>
+
+<p>&#8220;4. That they can ascend and descend hills of considerable
+inclination with facility and safety.</p>
+
+<p>&#8220;5. That they are perfectly safe for passengers.</p>
+
+<p>&#8220;6. That they are not (or need not be, if properly constructed)
+nuisances to the public.</p>
+
+<p>&#8220;7. That they will become a speedier and cheaper mode
+of conveyance than carriages drawn by horses.</p>
+
+<p>&#8220;8. That, as they admit of greater breadth of tire than
+other carriages, and as the roads are not acted on so injuriously
+as by the feet of horses in common draught, such carriages<span class='pagenum'><a name="Page_172" id="Page_172">[172]</a></span>
+will cause less wear of roads than coaches drawn by
+horses.</p>
+
+<p>&#8220;9. That rates of toll have been imposed on steam-carriages,
+which would prohibit their being used on several
+lines of road, were such charges permitted to remain unaltered.&#8221;</p>
+
+<p><span class="smcap">The Railroad</span>, which now, by the adaptation of steam
+to the propulsion of its carriages, became the successful
+rival of the system of transportation of which an account
+has just been given, was not a new device. It, like all
+other important changes of method and great inventions,
+had been growing into form for ages. The ancients were
+accustomed to lay down blocks of stone as a way upon
+which their heavily-loaded wagons could be drawn with less
+resistance than on the common road. This practice was
+gradually so modified as to result in the adoption of the
+now universally-practised methods of paving and road-making.
+The old tracks, bearing the marks of heavy traffic, are
+still seen in the streets of the unearthed city of Pompeii.</p>
+
+<p>In the early days of mining in Great Britain, the coal
+or the ore was carried from the mine to the vessel in which
+it was to be embarked in sacks on the backs of horses.
+Later, the miners laid out wagon-roads, and used carts and
+wagons drawn by horses, and the roads were paved with
+stone along the lines traversed by the wheels of the vehicles.
+Still later (about 1630), heavy planks or squared timber
+took the place of the stone, and were introduced into
+the north of England by a gentleman of the name of Beaumont,
+who had transferred his property there from the
+south. A half century later, the system had become generally
+introduced. By the end of the eighteenth century the
+construction of these &#8220;tram-ways&#8221; had become well-understood,
+and the economy which justified the expenditure of
+considerable amounts of money in making cuts and in filling,
+to bring the road to a uniform grade, had become well-recognized.
+Arthur Young, writing at this time, says the<span class='pagenum'><a name="Page_173" id="Page_173">[173]</a></span>
+coal wagon-roads were &#8220;great works, carried over all sorts
+of inequalities of ground, so far as the distance of nine or
+ten miles,&#8221; and that, on these tram-ways of timber, &#8220;one
+horse is able to draw, and that with ease, fifty or sixty
+bushels of coals.&#8221; The wagon-wheels were of cast-iron, and
+made with grooved rims, which fitted the rounded tops of
+the wooden rails. But these wooden rails were found subject
+to rapid decay, and at Whitehaven, in 1738, they were
+protected from wear by cast-iron plates laid upon them, and
+this improvement rapidly became known and adopted. A
+tram-road, laid down at Sheffield for the Duke of Norfolk,
+in 1776, was made by laying angle-bars of cast-iron on longitudinal
+sleepers of timber; another, built by William
+Jessup in Leicestershire, in 1789, had an edge-rail, and the
+wheels were made with flanges, like those used to-day. The
+coned &#8220;tread&#8221; of the wheel, which prevents wear of flanges
+and reduces resistance, was the invention of James Wright,
+of Columbia, Pa., 40 years later. The modern railroad was
+simply the result of this gradual improvement of the permanent
+way, and the adaptation of the steam-engine to the
+propulsion of its wagons.</p>
+
+<p>At the beginning of the nineteenth century, therefore,
+the steam-engine had been given a form which permitted
+its use, and the railroad had been so far perfected that there
+were no difficulties to be anticipated in the construction of
+the permanent way, and inventors were gradually preparing,
+as has been seen, to combine these two principal elements
+into one system. Railroads had been introduced in
+all parts of Great Britain, some of them of considerable
+length, and involving the interests of so many private individuals
+that they were necessarily constructed under the
+authorization of legal enactments. In the year 1805 the
+Merstham Railway was opened to traffic, and it is stated
+that on that occasion one horse drew a train of 12 wagons,
+carrying 38 tons of stone, on a &#8220;down gradient&#8221; of 1 in 120,
+at the rate of 6 miles per hour.</p>
+
+<div class="figcenter"><a name="Port7" id="Port7"></a>
+<img src="images/illo201.png" alt="Trevithick" width="350" height="417" />
+<p class="caption">Richard Trevithick.</p></div>
+
+<p><span class='pagenum'><a name="Page_174" id="Page_174">[174]</a></span><span class="smcap"><a href="#Port7">Richard
+Trevithick</a></span> was the first engineer to apply
+steam-power to the haulage of loads on the railroad. Trevithick
+was a Cornishman by birth, a native of Redruth.
+He was naturally a skillful mechanic, and was placed by his
+father with Watt&#8217;s assistant, Murdoch, who was superintending
+the erection of pumping-engines in Cornwall; and
+from that ingenious and accomplished engineer young Trevithick
+probably acquired both the skill and the knowledge
+which, with his native talent, enterprise, and industry, enabled
+him to accomplish the work which has made him famous.
+He was soon intrusted with the erection and management
+of large pumping-engines, and subsequently went into the
+business of constructing steam-engines with another engineer,
+Edward Bull, who took an active part, with the<span class='pagenum'><a name="Page_175" id="Page_175">[175]</a></span>
+Hornblowers and others, in opposing the Boulton &amp; Watt
+patents. The termination of the suits which established the
+validity of Watt&#8217;s patent put an end to their business, and
+Trevithick looked about for other work, and, not long
+after, entered into partnership with a relative, Andrew
+Vivian, who was also a skillful mechanic; they together designed
+and patented the steam-carriage already referred to.
+Its success was sufficiently satisfactory to awaken strong
+confidence of a perfect success on the now common tram-roads;
+and Trevithick, in February, 1804, had completed a
+&#8220;locomotive&#8221; engine to work on the Welsh Pen-y-darran
+road. This engine (<a href="#Fig50">Fig. 50</a>) had a cylindrical flue-boiler,
+<i>A</i>, like that designed by Oliver Evans, and a single steam-cylinder,
+<i>B</i>, set vertically into the steam-space of the boiler,<span class='pagenum'><a name="Page_176" id="Page_176">[176]</a></span>
+and driving the outside cranks, <i>L</i>, on the rear axle of the
+engine by very long connecting-rods, <i>D</i>, attached to its
+cross-head at <i>E</i>. The guide-bars, <i>I</i>, were stayed by braces
+leading to the opposite end of the boiler. No attempt
+was made to condense the exhaust-steam, which was discharged
+into the smoke-pipe. The pressure of steam
+adopted was 40 pounds per square inch; but Trevithick
+had already made a number of non-condensing engines on
+which he carried from 50 to 145 pounds pressure.</p>
+
+<div class="figcenter"><a name="Fig50" id="Fig50"></a>
+<img src="images/illo202.png" alt="Trevithick's Locomotive" width="400" height="403" />
+<p class="caption"><span class="smcap">Fig. 50.</span>&mdash;Trevithick&#8217;s Locomotive, 1804.</p></div>
+
+<p>In the year 1808, Trevithick built a railroad in London,
+on what was known later as Torrington Square, or Euston
+Square, and set at work a steam-carriage, which he called
+&#8220;Catch-me-who-can.&#8221; This was a very plain and simple
+machine. The steam-cylinder was set vertically in the
+after-end of the boiler, and the cross-head was connected to
+two rods, one on either side, driving the hind pair of wheels.
+The exhaust-steam entered the chimney, aiding the draught.
+This engine, weighing about 10 tons, made from 12 to 15
+miles an hour on the circular railway in London, and was
+said by its builder to be capable of making 20 miles an hour.
+The engine was finally thrown from the track, after some
+weeks of work, by the breaking of a rail, and, Trevithick&#8217;s
+funds having been expended, it was never replaced. This
+engine had a steam-cylinder 14<span class="enum">1</span>&#8725;<span class="denom">2</span> inches in diameter, and a
+stroke of piston of 4 feet. Trevithick used no device to aid
+the friction of the wheels on the rails in giving pulling-power,
+and seems to have understood that none was needed.
+This plan of working a locomotive-engine without such
+complications as had been proposed by other engineers was,
+however, subsequently patented, in 1813, by Blackett &amp;
+Hedley. The latter was at one time Trevithick&#8217;s agent,
+and was director of Wylam Colliery, of which Mr. Blackett
+was proprietor.</p>
+
+<p>Trevithick applied his high-pressure non-conducting engine
+not only to locomotives, but to every purpose that opportunity
+offered him. He put one into the Tredegar Iron-Works,<span class='pagenum'><a name="Page_177" id="Page_177">[177]</a></span>
+to drive the puddle-train, in 1801. This engine had
+a steam-cylinder 28 inches in diameter, and 6 feet stroke of
+piston; a boiler of cast-iron, 6<span class="enum">3</span>&#8725;<span class="denom">4</span> feet in diameter and 20 feet
+long, with a wrought-iron internal tube, 3 feet in diameter
+at the furnace-end and 24 inches beyond the furnace. The
+steam-pressure ranged from 50 to 100 pounds per square
+inch. The valve was a four-way cock. The exhaust-steam
+was carried into the chimney, passing through a feed-water
+heater <i>en route</i>. This engine was taken down in 1856.<a name="FNanchor_48_48"
+id="FNanchor_48_48"></a><a href="#Footnote_48_48" class="fnanchor">[48]</a></p>
+
+<p>In 1803, Trevithick applied his engine to driving rock-drills,
+and three years later made a large contract with the
+Trinity Board for dredging in the Thames, and constructed
+steam dredging-machines for the work, of the form which
+is still most generally used in Great Britain, although rarely
+seen in the United States&mdash;the &#8220;chain-and-bucket dredger.&#8221;</p>
+
+<p>A little later, Trevithick was engaged upon the first and
+unsuccessful attempt to carry a tunnel under the Thames, at
+London; but no sooner had that costly scheme been given
+up, than he returned to his favorite pursuits, and continued
+his work on interrupted schemes for ship-propulsion. Trevithick
+at last left England, spent some years in South America,
+and finally returned home and died in extreme poverty,
+April, 1833, at the age of sixty-two, without having
+succeeded in accomplishing the general introduction of any
+of his inventions.</p>
+
+<p>Trevithick was characteristically an inventor of the typical
+sort. He invented many valuable devices, but brought
+but few into even experimental use, and reaped little advantage
+from any of them. He was ingenious, a thorough mechanic,
+bold, active, and indefatigable; but his lack of persistence
+made his whole life, as Smiles has said, &#8220;but a
+series of beginnings.&#8221;</p>
+
+<p>It is at about this period that we find evidence of the
+intelligent labors of another of our own countrymen&mdash;one<span class='pagenum'><a name="Page_178" id="Page_178">[178]</a></span>
+who, in consequence of the unobtrusive manner in which
+his work was done, has never received the full credit to
+which he is entitled.</p>
+
+<div class="center"><a name="Port8" id="Port8"></a>
+<img src="images/illo205.png" alt="Colonel Stevens" width="350" height="413" />
+<p class="caption">Colonel John Stevens.</p></div>
+
+<p><a name="Stevens" id="Stevens"></a><span class="smcap">Colonel John Stevens</span>, of Hoboken, as he is generally
+called, was born in the city of New York, in 1749; but
+throughout his business-life he was a resident of New Jersey.</p>
+
+<p>His attention is said to have been first called to the application
+of steam-power by seeing the experiments of John
+Fitch with his steamer on the Delaware, and he at once devoted
+himself to the introduction of steam-navigation with
+characteristic energy, and with a success that will be indicated
+when we come to the consideration of that subject.</p>
+
+<p>But this far-sighted engineer and statesman saw plainly<span class='pagenum'><a name="Page_179" id="Page_179">[179]</a></span>
+the importance of applying the steam-engine to land-transportation
+as well as to navigation; and not only that, but
+he saw with equal distinctness the importance of a well-devised
+and carefully-prosecuted scheme of internal communication
+by a complete system of railroads. In 1812 he
+published a pamphlet containing &#8220;Documents tending to
+prove the superior advantages of Railways and Steam-Carriages
+over Canal-Navigation.&#8221;<a name="FNanchor_49_49" id="FNanchor_49_49"></a><a
+href="#Footnote_49_49" class="fnanchor">[49]</a> At this time, the only
+locomotive in the world was that of Trevithick and Vivian,
+at Merthyr Tydvil, and the railroad itself had not grown
+beyond the old wooden tram-roads of the collieries. Yet
+Colonel Stevens says, in this paper: &#8220;I can see nothing to
+hinder a steam-carriage moving on its ways with a velocity
+of 100 miles an hour;&#8221; adding, in a foot-note: &#8220;This astonishing
+velocity is considered here merely possible. It is
+probable that it may not, in practise, be convenient to exceed
+20 or 30 miles per hour. Actual experiment can only
+determine this matter, and I should not be surprised at
+seeing steam-carriages propelled at the rate of 40 or 50
+miles an hour.&#8221;
+</p>
+
+<p>At a yet earlier date he had addressed a memoir to the
+proper authorities, urging his plans for railroads. He
+proposed rails of timber, protected, when necessary, by
+iron plates, or to be made wholly of iron; the car-wheels
+were to be of cast-iron, with inside flanges to keep them on
+the track. The steam-engine was to be driven by steam of
+50 pounds pressure and upward, and to be non-condensing.</p>
+
+<p>Answering the objections of Robert R. Livingston and
+of the State Commissioners of New York, he goes further into
+details. He gives 500 to 1,000 pounds as the maximum
+weight to be placed on each wheel; shows that the trains, or
+&#8220;suits of carriages,&#8221; as he calls them, will make their journeys
+with as much certainty and celerity in the darkest night
+as in the light of day; shows that the grades of proposed<span class='pagenum'><a name="Page_180" id="Page_180">[180]</a></span>
+roads would offer but little resistance; and places the whole
+subject before the public with such accuracy of statement
+and such evident appreciation of its true value, that every
+one who reads this remarkable document will agree fully
+with President Charles King, who said<a name="FNanchor_50_50" id="FNanchor_50_50"></a><a
+href="#Footnote_50_50" class="fnanchor">[50]</a> that &#8220;whosoever
+shall attentively read this pamphlet, will perceive that the
+political, financial, commercial, and military aspects of this
+great question were all present to Colonel Stevens&#8217;s mind,
+and that he felt that he was fulfilling a patriotic duty when
+he placed at the disposal of his native country these fruits
+of his genius. The offering was not then accepted. The
+&#8216;Thinker&#8217; was ahead of his age; but it is grateful to know
+that he lived to see his projects carried out, though not by
+the Government, and that, before he finally, in 1838, closed
+his eyes in death, at the great age of eighty-nine, he could
+justly feel assured that the name of Stevens, in his own
+person and in that of his sons, was imperishably enrolled
+among those which a grateful country will cherish.&#8221;</p>
+
+<p>Without having made any one superlatively great improvement
+in the mechanism of the steam-engine, like that
+which gave Watt his fame&mdash;without having the honor even
+of being the first to propose the propulsion of vessels by the
+modern steam-engine, or steam-transportation on land&mdash;he
+exhibited a far better knowledge of the science and the art
+of engineering than any man of his time; and he entertained
+and urged more advanced opinions and more statesmanlike
+views in relation to the economical importance of
+the improvement and the application of the steam-engine,
+both on land and water, than seem to be attributable to
+any other leading engineer of that time.</p>
+
+<p>Says Dr. King: &#8220;Who can estimate if, at that day, acting
+upon the well-considered suggestion of President Madison,
+&#8216;of the signal advantages to be derived to the United
+States from a general system of internal communication and<span class='pagenum'><a name="Page_181" id="Page_181">[181]</a></span>
+conveyance,&#8217; Congress had entertained Colonel Stevens&#8217;s
+proposal, and, after verifying by actual experiment upon a
+small scale the accuracy of his plan, had organized such a
+&#8216;general system of internal communication and conveyance;&#8217;
+who can begin to estimate the inappreciable benefits
+that would have resulted therefrom to the comfort, the
+wealth, the power, and, above all, to the absolutely impregnable
+union of our great Republic and all its component
+parts? All this Colonel Stevens embraced in his views,
+for he was a statesman as well as an experimental philosopher;
+and whoever shall attentively read his pamphlet, will
+perceive that the political, financial, commercial, and military
+aspects of this great question were all present to his
+mind, and he felt that he was fulfilling a patriotic duty
+when he placed at the disposal of his native country these
+fruits of his genius.&#8221;</p>
+
+<p><span class="smcap">William Hedley</span>, who has already been referred to,
+seems to have been the first to show, by carefully-conducted
+experiment, how far the adhesion of the wheels of the locomotive-engine
+could be relied upon for hauling-power in
+the transportation of loads.</p>
+
+<p>His employer, Blackett, had applied to Trevithick for a
+locomotive-engine to haul coal-trains at the Wylam collieries;
+but Trevithick was unable, or was disinclined, to build
+him one, and in October, 1812, Hedley was authorized to
+attempt the construction of an engine. It was at about
+this time that Blenkinsop (1811) was trying the toothed rail
+or rack, the Messrs. Chapman (December, 1812) were experimenting
+with a towing-chain, and (May, 1813) Brunton
+with movable legs.</p>
+
+<p>Hedley, who had known of the success met with in the
+experiments of Trevithick with smooth wheels hauling loads
+of considerable weight, in Cornwall, was confident that equal
+success might be expected in the north-country, and built
+a carriage to be moved by men stationed at four handles,
+by which its wheels were turned.</p>
+
+<p><span class='pagenum'><a name="Page_182" id="Page_182">[182]</a></span>This carriage was loaded with heavy masses of iron, and
+attached to trains of coal-wagons on the railway. By repeated
+experiment, varying the weight of the traction-carriage
+and the load hauled, Hedley ascertained the proportion
+of the weight required for adhesion to that of the loads
+drawn. It was thus conclusively proven that the weight of
+his proposed locomotive-engine would be sufficient to give
+the pulling-power necessary for the propulsion of the coal-trains
+which it was to haul.</p>
+
+<p>When the wheels slipped in consequence of the presence
+of grease, frost, or moisture on the rail, Hedley proposed to
+sprinkle ashes on the track, as sand is now distributed from
+the sand-box of the modern engine. This was in October,
+1812.</p>
+
+<p>Hedley now went to work building an engine with
+smooth wheels, and patented his design March 13, 1813, a
+month after he had put his engine at work. The locomotive
+had a cast-iron boiler, and a single steam-cylinder 6
+inches in diameter, with a small fly-wheel. This engine
+had too small a boiler, and he soon after built a larger engine,
+with a return-flue boiler made of wrought-iron. This
+hauled 8 loaded coal-wagons 5 miles an hour at first, and a
+little later 10, doing the work of 10 horses. The steam-pressure
+was carried at about 50 pounds, and the exhaust,
+led into the chimney, where the pipe was turned upward,
+thus secured a blast of considerable intensity in its small
+chimney. Hedley also contracted the opening of the exhaust-pipe
+to intensify the blast, and was subjected to some
+annoyance by proprietors of lands along his railway, who
+were irritated by the burning of their grass and hedges,
+which were set on fire by the sparks thrown out of the
+chimney of the locomotive. The cost of Hedley&#8217;s experiment
+was defrayed by Mr. Blackett.</p>
+
+<p>Subsequently, Hedley mounted his engine on eight
+wheels, the four-wheeled engines having been frequently
+stopped by breaking the light rails then in use. Hedley&#8217;s<span class='pagenum'><a name="Page_183" id="Page_183">[183]</a></span>
+engines continued in use at the Wylam collieries many
+years. The second engine was removed in 1862, and is now
+preserved at the South Kensington Museum, London.</p>
+
+<div class="figcenter"><a name="Port9" id="Port9"></a>
+<img src="images/illo210.png" alt="Stephenson" width="350" height="413" />
+<p class="caption">George Stephenson.</p></div>
+
+<p><span class="smcap"><a href="#Port9">George Stephenson</a></span>, to whom is generally accorded
+the honor of having first made the locomotive-engine a success,
+built his first engine at Killingworth, England, in 1814.</p>
+
+<p>At this time Stephenson was by no means alone in the
+field, for the idea of applying the steam-engine to driving
+carriages on common roads and on railroads was beginning,
+as has been seen, to attract considerable attention. Stephenson,
+however, combined, in a very fortunate degree,
+the advantages of great natural inventive talent and an
+excellent mechanical training, reminding one strongly of
+James Watt. Indeed, Stephenson&#8217;s portrait bears some
+resemblance to <a href="#Port4">that</a> of the earlier great inventor.</p>
+
+<p>George Stephenson was born June 9, 1781, at Wylam,<span class='pagenum'><a name="Page_184" id="Page_184">[184]</a></span>
+near Newcastle-upon-Tyne, and was the son of a &#8220;north-country
+miner.&#8221; When still a child, he exhibited great mechanical
+talent and unusual love of study. When set at
+work about the mines, his attention to duty and his intelligence
+obtained for him rapid promotion, until, when but
+seventeen years of age, he was made engineer, and took
+charge of the pumping-engine at which his father was fireman.</p>
+
+<p>When a mere child, and employed as a herd-boy, he
+amused himself making model engines in clay, and, as he
+grew older, never lost an opportunity to learn the construction
+and management of machinery. After having been
+employed at Newburn and Callerton, where he first became
+&#8220;engine-man,&#8221; he began to study with greater interest than
+ever the various steam-engines which were then in use; and
+both the Newcomen engine and the Watt pumping-engine
+were soon thoroughly understood by him. After having
+become a brakeman, he removed to Willington Quay,
+where he married, and commenced his wedded life on 18 or
+20 shillings per week. It was here that he became an intimate
+friend of the distinguished William Fairbairn, who
+was then working as an apprentice at the Percy Main
+Colliery, near by. The &#8220;father of the railroad&#8221; and the
+future President of the British Association were accustomed,
+at times, to &#8220;change works,&#8221; and were frequently
+seen in consultation over their numerous projects. It was
+at Willington Quay that his son Robert, who afterward
+became a distinguished civil engineer, was born, October
+16, 1803.</p>
+
+<p>In the following year Stephenson removed to Killingworth,
+and became brakeman at that colliery; but his
+wife soon died, and he gladly accepted an invitation to become
+engine-driver at a spinning-mill near Montrose, Scotland.
+At the end of a year he returned, on foot, to Killingworth
+with his savings (about &pound;28), expended over one-half
+of the amount in paying his father&#8217;s debts and in making<span class='pagenum'><a name="Page_185" id="Page_185">[185]</a></span>
+his parents comfortable, and then returned to his old
+station as brakeman at the pit.</p>
+
+<p>Here he made some useful improvements in the arrangement
+of the machinery, and spent his spare hours in studying
+his engine and planning new machines. He a little
+later distinguished himself by altering and repairing an
+old Newcomen engine at the High Pit, which had failed
+to give satisfaction, making it thoroughly successful after
+three days&#8217; work. The engine cleared the pit, at which it
+had been vainly laboring a long time, in two days after
+Stephenson started it up.</p>
+
+<p>In the year 1812, Stephenson was made engine-wright of
+the Killingworth High Pit, receiving &pound;100 a year, and it was
+made his duty to supervise the machinery of all the collieries
+under lease by the so-called &#8220;Grand Allies.&#8221; It was
+here, and at this period, that he commenced a systematic
+course of self-improvement and the education of his son,
+and here he first began to be recognized as an inventor.
+He was full of life and something of a wag, and often made
+most amusing applications of his inventive powers: as when
+he placed the watch, which a comrade had brought him as
+out of repairs, in the oven &#8220;to cook,&#8221; his quick eye having
+noted the fact that the difficulty arose simply from the
+clogging of the wheels by the oil, which had been congealed
+by cold.</p>
+
+<p>Smiles,<a name="FNanchor_51_51" id="FNanchor_51_51"></a><a href="#Footnote_51_51"
+class="fnanchor">[51]</a> his biographer, describes his cottage as a perfect
+curiosity-shop, filled with models of engines, machines of
+various kinds, and novel apparatus. He connected the cradles
+of his neighbors&#8217; wives with the smoke-jacks in their
+chimneys, and thus relieved them from constant attendance
+upon their infants; he fished at night with a submarine
+lamp, which attracted the fish from all sides, and gave him
+wonderful luck; he also found time to give colloquial instruction
+to his fellow-workmen.</p>
+
+<p><span class='pagenum'><a name="Page_186" id="Page_186">[186]</a></span>He built a self-acting inclined plane for his pit, on which
+the wagons, descending loaded, drew up the empty trains;
+and made so many improvements at the Killingworth pit,
+that the number of horses employed underground was reduced
+from 100 to 16.</p>
+
+<p>Stephenson now had more liberty than when employed
+at the brakes, and, hearing of the experiments of Blackett
+and Hedley at Wylam, went over to their colliery to study
+their engine. He also went to Leeds to see the Blenkinsop
+engine draw, at a trial, 70 tons at the rate of 3 miles
+an hour, and expressed his opinion in the characteristic remark,
+&#8220;I think I could make a better engine than that to
+go upon legs.&#8221; He very soon made the attempt.</p>
+
+<p>Having laid the subject before the proprietors of the
+lease under which the collieries were worked, and convinced
+Lord Ravensworth, the principal owner, of the advantages
+to be secured by the use of a &#8220;traveling engine,&#8221; that
+nobleman advanced the money required. Stephenson at
+once commenced his first locomotive-engine, building it in
+the workshops at West Moor, assisted mainly by John
+Thirlwall, the colliery blacksmith, during the years 1813
+and 1814, completing it in July of the latter year.</p>
+
+<p>This engine had a wrought-iron boiler 8 feet long and
+2 feet 10 inches in diameter, with a single flue 20 inches in
+diameter. The cylinders were vertical, 8 inches in diameter
+and of 2 feet stroke of piston, set in the boiler, and
+driving a set of wheels which geared with each other and
+with other cogged wheels on the two driving-axles. A feed-water
+heater surrounded the base of the chimney. This
+engine drew 30 tons on a rising gradient of 10 or 12 feet to
+the mile at the rate of 4 miles an hour. This engine proved
+in many respects defective, and the cost of its operation
+was found to be about as great as that of employing horse-power.</p>
+
+<p>Stephenson determined to build another engine on a
+somewhat different plan, and patented its design in February,<span class='pagenum'><a name="Page_187" id="Page_187">[187]</a></span>
+1815. It proved a much more efficient machine than
+the &#8220;Bl&uuml;cher,&#8221; the first engine.</p>
+
+<div class="figcenter"><a name="Fig51" id="Fig51"></a>
+<img src="images/illo214.png" alt="Stephenson's Locomotive of 1815" width="448" height="350" />
+<p class="caption"><span class="smcap">Fig. 51.</span>&mdash;Stephenson&#8217;s Locomotive of 1815. Section.</p></div>
+
+<p>This second engine (<a href="#Fig51">Fig. 51</a>) was also fitted with two
+vertical cylinders, <i>C c</i>, but the connecting-rods were attached
+directly to the four driving-wheels, <i>W W&#8242;</i>. To permit
+the necessary freedom of motion, &#8220;ball-and-socket&#8221;
+joints were adopted, to unite the rods with the cross-heads,
+<i>R r</i>, and with the cranks, <i>R&#8242; Y&#8242;</i>; and the two driving-axles
+were connected by an endless chain, <i>T t&#8242;</i>. The cranked axle
+and the outside connection of the wheels, as specified in the
+patent, were not used until afterward, it having been found
+impossible to get the cranked axles made. In this engine
+the forced draught obtained by the impulse of the exhaust-steam
+was adopted, doubling the power of the machine and
+permitting the use of coke as a fuel, and making it possible
+to adopt the multi-tubular boiler. Small steam-cylinders,
+<i>S S S</i>, took the weight of the engine and served as springs.</p>
+
+<p>It was at about this time that George Stephenson and<span class='pagenum'><a name="Page_188" id="Page_188">[188]</a></span>
+Sir Humphry Davy, independently and almost simultaneously,
+invented the &#8220;safety-lamp,&#8221; without which few mines
+of bituminous coal could to-day be worked. The former
+used small tubes, the latter fine wire gauze, to intercept the
+flame. Stephenson proved the efficiency of his lamp by
+going with it directly into the inflammable atmosphere of a
+dangerous mine, and repeatedly permitting the light to be
+extinguished when the lamp became surcharged with the
+explosive mixture which had so frequently proved fatal to
+the miners. This was in October and November, 1815, and
+Stephenson&#8217;s work antedates that of the great philosopher.<a name="FNanchor_52_52"
+id="FNanchor_52_52"></a><a href="#Footnote_52_52" class="fnanchor">[52]</a>
+The controversy which arose between the supporters of the
+rival claims of the two inventors was very earnest, and
+sometimes bitter. The friends of the young engineer raised
+a subscription, amounting to above &pound;1,000, and presented it
+to him as a token of their appreciation of the value of his
+simple yet important contrivance. Of the two forms of
+lamp, that of Stephenson is claimed to be safest, the Davy
+lamp being liable to produce explosions by igniting the explosive
+gas when, by its combustion within the gauze cylinder,
+the latter is made red-hot. Under similar conditions,
+the Stephenson lamp is simply extinguished, as was seen at
+Barnsley, in 1857, at the Oaks Colliery, where both kinds
+of lamp were in use, and elsewhere.</p>
+
+<p>Stephenson continued to study and experiment, with a
+view to the improvement of his locomotive and the railroad.
+He introduced better methods of track-laying and of
+jointing the rails, adopting a half-lap, or peculiar scarf-joint,
+in place of the then usual square-butt joint. He patented,
+with these modifications of the permanent way, several
+of his improvements of the engine. He had substituted
+forged for the rude cast wheels previously used,<a name="FNanchor_53_53" id="FNanchor_53_53"></a><a
+href="#Footnote_53_53" class="fnanchor">[53]</a> and had<span class='pagenum'><a name="Page_189" id="Page_189">[189]</a></span>
+made many minor changes of detail. The engines built
+at this time (1816) continued in use many years. Two
+years later, with a dynamometer which he designed for the
+purpose, he made experimental determinations of the resistance
+of trains, and showed that it was made up of several
+kinds, as the sliding friction of the axle-journals in their
+bearings, the rolling friction of the wheels on the rails, the
+resistance due to gravity on gradients, and that due to the
+resistance of the air.</p>
+
+<p>These experiments seemed to him conclusive against the
+possibility of the competition of engines on the common
+highway with locomotives hauling trains on the rail. Finding
+that the resistance, with his rolling-stock, and at all the
+speeds at which he made his experiments, was approximately
+invariable, and equivalent to about 10 pounds per ton,
+and estimating that a gradient rising but 1 foot in 100
+would decrease the hauling power of the engine 50 per
+cent., he saw at once the necessity of making all railroads
+as nearly absolutely level as possible, and, consequently, the
+radically distinctive character of this branch of civil engineering
+work. He persistently condemned the &#8220;folly&#8221; of
+attempting the general introduction of steam on the common
+road, where great changes of level and an impressible
+road-bed were certain to prove fatal to success, and was
+most strenuous in his advocacy of the policy of securing
+level tracks, even at very great expense.</p>
+
+<p>Taking part in the contest, which now became a serious
+one, between the advocates of steam on the common road
+and those urging the introduction of locomotives and their
+trains on an iron track, he calculated that a road-engine
+capable of carrying 20 or 30 passengers at 10 miles per hour,
+could, on the rail, carry ten times as many people at three
+or four times that speed. The railway-engine finally superseded
+its predecessor&mdash;the engine of the common road&mdash;almost
+completely.</p>
+
+<p>In 1817, Stephenson built an engine for the Duke of<span class='pagenum'><a name="Page_190" id="Page_190">[190]</a></span>
+Portland, to haul coal from Kilmarnock to Troon, which
+cost &pound;750, and, with some interruptions, this engine worked
+on that line until 1848, when it was broken up. On November
+18, 1822, the Hetton Railway, near Sunderland, was
+opened. George Stephenson was the engineer of the line&mdash;a
+short track, 8 miles long, built from the Hetton Colliery to
+the docks on the bank of the river Wear. On this line he
+put in five of the &#8220;self-acting inclines&#8221;&mdash;two inclines worked
+by stationary engines, the gradients being too heavy for
+locomotives&mdash;and used five locomotive-engines of his own
+design, which were called by the people of the neighborhood,
+possibly for the first time, &#8220;the iron horses.&#8221; These
+engines were quite similar to the Killingworth engine.
+They drew a train of 17 coal-cars&mdash;a total load of 64 tons&mdash;about
+4 miles an hour. Meantime, also, in 1823, Stephenson
+had been made engineer of the Stockton &amp; Darlington
+Railroad, which had been projected for the purpose
+of securing transportation to tide-water for the valuable
+coal-lands of Durham. This road was built without an expectation
+on the part of any of its promoters, Stephenson
+excepted, that steam would be used as a motor to the exclusion
+of horses.</p>
+
+<p>Mr. Edward Pearse, however, one of the largest holders
+of stock in the road, and one of its most earnest advocates,
+became so convinced, by an examination of the Killingworth
+engines and their work, of the immense advantage to
+be derived by their use, that he not only supported Stephenson&#8217;s
+arguments, but, with Thomas Richardson, advanced
+&pound;1,000 for the purpose of assisting Stephenson to
+commence the business of locomotive-engine construction at
+Newcastle. This workshop, which subsequently became a
+great and famous establishment, was commenced in 1824.</p>
+
+<div class="figcenter"><a name="Fig52" id="Fig52"></a>
+<img src="images/illo218.png" alt="Stephenson's No. 1 Engine" width="400" height="281" />
+<p class="caption"><span class="smcap">Fig. 52.</span>&mdash;Stephenson&#8217;s No. 1 Engine, 1825.</p></div>
+
+<p>For this road Stephenson recommended wrought-iron
+rails, which were then costing &pound;12 per ton&mdash;double the price
+of cast rails. The directors, however, stipulated that he
+should only buy one-half the rails required from the dealers<span class='pagenum'><a name="Page_191" id="Page_191">[191]</a></span>
+in &#8220;malleable&#8221; iron. These rails weighed 20 pounds to the
+yard. After long hesitation, in the face of a serious opposition,
+the directors finally concluded to order three locomotives
+of Stephenson. The first, or &#8220;No. 1,&#8221; engine (<a href="#Fig52">Fig. 52</a>)
+was delivered in time for the opening of the road, September
+27, 1825. It weighed 8 tons. Its boiler contained a single
+straight flue, one end of which was the furnace. The
+cylinders were vertical, like those of the earlier engines, and
+coupled directly to the driving-wheels. The crank-pins
+were set in the wheels at right angles, in order that, while
+one engine was &#8220;turning the centre,&#8221; the other might exert
+its maximum power. The two pairs of drivers were coupled
+by horizontal rods, as seen in the figure, which represents
+this engine as subsequently mounted on a pedestal at the Darlington
+station. A steam-blast in the chimney gave the
+requisite strength of draught. These engines were built for
+slow and heavy work, but were capable of making what was
+then thought the satisfactorily high speed of 16 miles per
+hour. The inclines on the road were worked by fixed engines.</p>
+
+<p>On the <a href="#Fig53">opening day</a>, which was celebrated as a holiday<span class='pagenum'><a name="Page_192" id="Page_192">[192]</a></span>
+by the people far and near, the No. 1 engine drew 90 tons
+at the rate of 12, and at times 15, miles an hour.</p>
+
+<div class="figcenter"><a name="Fig53" id="Fig53"></a>
+<img src="images/illo219.png" alt="Opening of Darlington Railroad" width="600" height="282" />
+<p class="caption"><span class="smcap">Fig. 53.</span>&mdash;Opening of the Stockton and Darlington
+Railroad, 1815.<br />(After an old engraving.)</p></div>
+
+<p>Stephenson&#8217;s engines were kept at work hauling coal-trains,<span class='pagenum'><a name="Page_193" id="Page_193">[193]</a></span>
+but the passenger-coaches were all drawn for some
+time by horses, and the latter system was a rude forerunner,
+in most respects, of modern street-railway transportation.
+Mixed passenger and freight trains were next introduced,
+and, soon after, separate passenger-trains drawn by faster
+engines were placed on the line, and the present system of
+railroad transportation was now fairly inaugurated.</p>
+
+<p>A railroad between Manchester and Liverpool had been
+projected at about the time that the Stockton &amp; Darlington
+road was commenced. The preliminary surveys had
+been made in the face of strong opposition, which did not
+always stop at legal action and verbal attack, but in
+some instances led to the display of force. The surveyors
+were sometimes driven from their work by a mob armed
+with sticks and stones, urged on by land-proprietors and
+those interested in the lines of coaches on the highway.
+Before the opening of the Stockton &amp; Darlington Railroad,
+the Liverpool &amp; Manchester bill had been carried
+through Parliament, after a very determined effort on the
+part of coach-proprietors and landholders to defeat it, and
+Stephenson urged the adoption of the locomotive to the
+exclusion of horses. It was his assertion, made at this
+time, that he could build a locomotive to run 20 miles an
+hour, that provoked the celebrated rejoinder of a writer in
+the <i>Quarterly Review</i>, who was, however, in favor of the
+construction of the road and of the use of the locomotive
+upon it: &#8220;What can be more palpably absurd and ridiculous,
+than the prospect held out of locomotives traveling
+<i>twice as fast</i> as stage-coaches? We would as soon expect
+the people of Woolwich to suffer themselves to be fired off
+upon one of Congreve&#8217;s ricochet-rockets, as trust themselves
+to the mercy of such a machine going at such a rate.&#8221;</p>
+
+<p>It was during his examination before a committee of
+the House of Commons, during this contest, that Stephenson,
+when asked, &#8220;Suppose, now, one of your engines to
+be going at the rate of 9 or 10 miles an hour, and that a<span class='pagenum'><a name="Page_194" id="Page_194">[194]</a></span>
+cow were to stray upon the line and get in the way of the
+engine, would not that be a very awkward circumstance?&#8221;
+replied, &#8220;Yes, <i>very</i> awkward&mdash;<i>for the coo!</i>&#8221; And when
+asked if men and animals would not be frightened by the
+red-hot smoke-pipe, answered, &#8220;But how would they know
+that it was not <i>painted?</i>&#8221; The line was finally built, with
+George Rennie as consulting, and Stephenson as principal
+constructing engineer.</p>
+
+<p>His work on this road became one of the important
+elements of the success, and one of the great causes
+of the distinction, which marked the life of these rising
+engineers. The successful construction of that part of
+the line which lay across &#8220;Chat Moss,&#8221; an unfathomable
+swampy deposit of peat, extending over an area of 12
+square miles, and the building of which had been repeatedly
+declared an impossibility, was in itself sufficient to
+prove that the engineer who had accomplished it was no
+common man. Stephenson adopted the very simple yet
+bold expedient of using, as a filling, compacted turf and peat,
+and building a road-bed of materials lighter than water,
+or the substance composing the bog, and thus forming a
+<i>floating</i> embankment, on which he laid his rails. To the
+surprise of every one but Stephenson himself, the plan
+proved perfectly successful, and even surprisingly economical,
+costing but little more than one-tenth the estimate of
+at least one engineer. Among the other great works on
+this remarkable pioneer-line were the tunnel, a mile and a
+half long, from the station at Liverpool to Edgehill; the
+Olive Mount deep-cut, two miles long, and in some places
+100 feet deep, through red sandstone, of which nearly
+500,000 yards were removed; the Sankey Viaduct, a brick
+structure of nine arches, of 50 feet span each, costing
+&pound;45,000; and a number of other pieces of work which are
+noteworthy in even these days of great works.</p>
+
+<p>Stephenson planned all details of the line, and even designed
+the bridges, machinery, engines, turn-tables, switches,<span class='pagenum'><a name="Page_195" id="Page_195">[195]</a></span>
+and crossings, and was responsible for every part of the
+work of their construction.</p>
+
+<p>Finally, the work of building the line approached completion,
+and it became necessary promptly to settle the long-deferred
+question of a method of applying motive-power.
+Some of the directors and their advisers still advocated the
+use of horses; many thought stationary hauling-engines
+preferable; and the remainder were, almost to a man, undecided.
+The locomotive had no outspoken advocate, and
+few had the slightest faith in it. George Stephenson was
+almost alone, and the opponents of steam had secured a
+provision in the Newcastle &amp; Carlisle Railroad concession,
+stipulating expressly that horses should there be exclusively
+employed. The directors did, however, in 1828, permit
+Stephenson to put on the line a locomotive, to be used, during
+its construction, in hauling gravel-trains. A committee
+was sent, at Stephenson&#8217;s request, to see the Stockton &amp;
+Darlington engines, but no decided expression of opinion
+seems to have been made by them. Two well-known professional
+engineers reported in favor of fixed engines, and
+advised the division of the line into 19 stages of about a
+mile and a half each, and the use of 21 fixed engines, although
+they admitted the excessive first-cost of that system.
+The board was naturally strongly inclined to adopt their
+plan. Stephenson, however, earnestly and persistently opposed
+such action, and, after long debate, it was finally determined
+&#8220;to give the traveling engine a chance.&#8221; The
+board decided to offer a reward of &pound;500 for the best locomotive-engine,
+and prescribed the following conditions:</p>
+
+<div class="blockquot"><p>1. The engine must consume its own smoke.</p>
+
+<p>2. The engine, if of 6 tons weight, must be able to draw after it, day
+by day, 20 tons weight (including the tender and water-tank) at 10 miles an
+hour, with a pressure of steam on the boiler not exceeding 50 pounds to the
+square inch.</p>
+
+<p>3. The boiler must have two safety-valves, neither of which must be fastened
+down, and one of them completely out of the control of the engine-man.</p>
+
+<p><span class='pagenum' style="font-size: 1em;"><a name="Page_196" id="Page_196">[196]</a></span>4.
+The engine and boiler must be supported on springs, and rest on 6
+wheels, the height of the whole not exceeding 15 feet to the top of the
+chimney.</p>
+
+<p>5. The engine, with water, must not weigh more than 6 tons; but an
+engine of less weight would be preferred, on its drawing a proportionate
+load behind it; if of only 4<span class="enum">1</span>&#8725;<span class="denom">2</span> tons, then it might be put only on 4 wheels.
+The company to be at liberty to test the boiler, etc., by a pressure of 150
+pounds to the square inch.</p>
+
+<p>6. A mercurial gauge must be affixed to the machine, showing the
+steam-pressure above 45 pounds to the square inch.</p>
+
+<p>7. The engine must be delivered, complete and ready for trial, at the
+Liverpool end of the railway, not later than the 1st of October, 1829.</p>
+
+<p>8. The price of the engine must not exceed &pound;550.</p></div>
+
+<p>This circular was printed and published throughout the
+kingdom, and a considerable number of engines were constructed
+to compete at the trial, which was proposed to
+take place October 1, 1829, but which was deferred to the
+6th of that month. Only four engines, however, were finally
+entered on the day of the trial. These were the &#8220;Novelty,&#8221;
+constructed by Messrs. Braithwaite &amp; Ericsson, the
+latter being the distinguished engineer who subsequently
+came to the United States to introduce screw-propulsion,
+and, later, the monitor system of iron-clads; the &#8220;Rocket,&#8221;
+built from Stephenson&#8217;s plans; and the &#8220;Sanspareil&#8221; and
+the &#8220;Perseverance,&#8221; built by Hackworth and Burstall, respectively.</p>
+
+<p>The &#8220;Sanspareil,&#8221; which was built under the direction
+of Timothy Hackworth, one of Stephenson&#8217;s earlier foremen,
+resembled the engine built by the latter for the Stockton
+&amp; Darlington road, but was heavier than had been stipulated,
+was not ready for work when called, and, when finally
+set at work, proved to be very extravagant in its use of
+fuel, partly in consequence of the extreme intensity of its
+blast, which caused the expulsion of unconsumed coals from
+the furnace.</p>
+
+<p>The &#8220;Perseverance&#8221; could not attain the specified speed,
+and was withdrawn.</p>
+
+<div class="figcenter"><a name="Fig54" id="Fig54"></a>
+<img src="images/illo224.png" alt="The 'Novelty'" width="450" height="278" />
+<p class="caption"><span class="smcap">Fig. 54.</span>&mdash;The &#8220;Novelty,&#8221; 1829.</p></div>
+
+<p><span class='pagenum'><a name="Page_197" id="Page_197">[197]</a></span>The &#8220;Novelty&#8221; was apparently a well-designed and for
+that time a remarkably well-proportioned machine. <i>A</i>, in
+<a href="#Fig54">Fig. 54</a>, is the boiler, <i>D</i> the steam-cylinders, <i>E</i> a heater.
+Its weight but slightly exceeded three tons, and it was a
+&#8220;tank engine,&#8221; carrying its own fuel and water at <i>B</i>. A
+forced draught was obtained by means of the bellows, <i>C</i>.
+This engine was run over the line at the rate of about 28
+miles an hour at times, but its blowing apparatus failed,
+and the &#8220;Rocket&#8221; held the track alone. A later trial still
+left the &#8220;Rocket&#8221; alone in the field.</p>
+
+<div class="figcenter"><a name="Fig55" id="Fig55"></a>
+<img src="images/illo225.png" alt="The 'Rocket'" width="350" height="283" />
+<p class="caption"><span class="smcap">Fig. 55.</span>&mdash;The &#8220;Rocket,&#8221; 1829.</p></div>
+
+<p>The &#8220;Rocket&#8221; (<a href="#Fig55">Fig. 55</a>) was built at the works of Robert
+Stephenson &amp; Co., at Newcastle-upon-Tyne. The boiler was
+given considerable heating-surface by the introduction of
+25 3-inch copper tubes, at the suggestion of Henry Booth,
+secretary of the railroad company. The blast was altered
+by gradually closing in the opening at the extremity of the
+exhaust-pipe, and thus &#8220;sharpening&#8221; it until it was found
+to have the requisite intensity. The effect of this modification
+of the shape of the pipe was observed carefully by
+means of syphon water-gauges attached to the chimney.
+The draft was finally given such an intensity as to raise the
+water 3 inches in the tube of the draught-gauge. The<span class='pagenum'><a name="Page_198" id="Page_198">[198]</a></span>
+total length of the boiler was 6 feet, its diameter 40 inches.
+The fire-box was attached to the rear of the boiler, and was
+3 feet high and 2 feet wide, with water-legs to protect its
+side-sheets from injury by overheating. The cylinders, as
+seen in the sketch, were inclined, and coupled to a single
+pair of driving-wheels. A tender, attached to the engine,
+carried the fuel and water. The engine weighed less than
+4<span class="enum">1</span>&#8725;<span class="denom">2</span> tons.</p>
+
+<p>The little engine does not seem to have been very prepossessing
+in appearance, and the &#8220;Novelty&#8221; is said to have
+been the general favorite, the Stephenson engine having
+few, if any, backers among the spectators. On its first
+trial, it ran 12 miles in less than an hour.</p>
+
+<p>After the accident which disabled the &#8220;Novelty,&#8221; the
+&#8220;Rocket&#8221; came forward again, and ran at the rate of from
+25 to 30 miles an hour, drawing a single carriage carrying 30
+passengers. Two days later, on the 8th of October, steam
+was raised in a little less than an hour from cold water, and<span class='pagenum'><a name="Page_199" id="Page_199">[199]</a></span>
+it then, with 13 tons of freight in the train, ran 35 miles in
+1 hour and 48 minutes, including stops, and attained a speed
+of 29 miles an hour. The average of all runs for the trial
+was 15 miles an hour.</p>
+
+<p>This success, far exceeding the expectation of the most
+sanguine of the advocates of the system, and greatly exceeding
+what had been asserted by opponents to be the
+bounds of possibility, settled completely the whole question,
+and the Manchester &amp; Liverpool road was at once
+equipped with locomotive engines.</p>
+
+<p>The &#8220;Rocket&#8221; remained on the line until 1837, when it
+was sold, and set at work by the purchasers on the Midgeholme
+Railway, near Carlisle. On one occasion, on this
+road, it was driven 4 miles in 4<span class="enum">1</span>&#8725;<span class="denom">2</span> minutes. It is now in the
+Patent Museum at South Kensington, London.</p>
+
+<p>In January, 1830, a single line of rails had been carried
+across Chat Moss, and, six months later, the first train,
+drawn by the &#8220;Arrow,&#8221; ran through, June 14th, from Liverpool
+to Manchester, making the trip in an hour and a
+half, and attaining a maximum speed of over 27 miles an
+hour. The line was formally opened to traffic September
+15, 1830.</p>
+
+<p>This was one of the most notable occasions in the history
+of the railroad, and the successful termination of the
+great work was celebrated, as so important an event should
+be, by impressive ceremonies. Among the distinguished
+spectators were Sir Robert Peel and the Duke of Wellington.
+Mr. Huskisson, a Member of Parliament for Liverpool,
+was also present. There had been built for the line, by Robert
+Stephenson &amp; Co., 7 locomotives besides the &#8220;Rocket,&#8221;
+and a large number of carriages. These were all brought
+out in procession, and 600 passengers entered the train,
+which started for Manchester, and ran at times, on smooth
+portions of the road, at the rate of 20 and 25 miles an hour.
+Crowds of people along the line cheered at this strange
+and to them incomprehensible spectacle, and the story of<span class='pagenum'><a name="Page_200" id="Page_200">[200]</a></span>
+the wonderful performances of that day on the new railroad
+was repeated in every corner of the land. A sad accident,
+the precursor of thousands to follow the introduction of the
+new method of transportation, while it repressed the rising
+enthusiasm of the people and dampened the ardor of the
+most earnest of the advocates of the railroad, occurring
+during this trip, assisted in making known the power of the
+new motor and the danger attending its use as well. The
+trains stopped for water at Parkside, and occasion was
+taken to send the &#8220;Northumbrian,&#8221; an engine driven by
+George Stephenson himself, on a side track, with the carriage
+containing the Duke of Wellington, and the other
+engines and trains were all directed to be sent along the
+main track in view of the Duke and his party. While this
+movement was in process of execution, Mr. Huskisson, who
+had carelessly stood on the main line until the &#8220;Rocket,&#8221;
+which led the column, had nearly reached him, attempted
+to enter the carriage of the Duke. He was too late, and
+was struck by the &#8220;Rocket,&#8221; thrown down across the rail,
+and the advancing engine crushed a leg so seriously that he
+died the same evening. Immediately after the accident, he
+was placed on the &#8220;Northumbrian,&#8221; and Stephenson made
+the 15 miles to the destination of the wounded man in 25
+minutes&mdash;a speed of 36 miles an hour. The news of this accident,
+and the statement of the velocity of the engine, were
+published throughout the kingdom and Europe; and the
+misfortune of this first victim of a railroad accident was one
+of the causes of the immediate adoption and rapid spread
+of the modern railway system.</p>
+
+<p>This road, which was built in the hope of securing 400
+passengers per day, almost immediately averaged 1,200, and
+in five years reported 500,000 passengers for the year.<a name="FNanchor_54_54" id="FNanchor_54_54"></a><a
+href="#Footnote_54_54" class="fnanchor">[54]</a> The
+success of this road insured the general introduction of
+railroads, and from this time forward there was never a<span class='pagenum'><a name="Page_201" id="Page_201">[201]</a></span>
+doubt of their ultimate adoption to the exclusion of every
+other system of general internal communication and transportation.</p>
+
+<p>For some years after this his first great triumph, George
+Stephenson gave his whole time to the building of railroads
+and the improvement of the engine. He was assisted by
+his son Robert, to whom he gradually surrendered his business,
+and retired to Tapton House, on the Midland Railway,
+and led a busy but pleasant life during the remaining years
+of his existence.</p>
+
+<p>Even as early as 1840, he seems to have projected many
+improvements which were only generally adopted many
+years later. He proposed self-acting and continuous systems
+of brake, and considered a good system of brake of so
+great importance, that he advocated their compulsory introduction
+by State legislation. He advised moderate speeds,
+from considerations both of safety and of expense.</p>
+
+<div class="figcenter"><a name="Fig56" id="Fig56"></a>
+<img src="images/illo229.png" alt="Atmospheric Railroad" width="332" height="400" />
+<p class="caption"><span class="smcap">Fig. 56.</span>&mdash;The Atmospheric Railroad.</p></div>
+
+<p>A few years after the opening of the Liverpool &amp;
+Manchester road, great numbers of schemes were proposed
+by ignorant or designing men, which had for their object
+the filling of the pockets of their proposers rather than the
+benefit of the stockholders and the public; and the Stephensons
+were often called upon to combat these crude and
+ill-digested plans. Among these was the pneumatic system
+of propulsion, already referred to as first proposed by Papin,
+in combination with his double-acting air-pump, in 1687.
+It had been again proposed in the early part of the present
+century by Medhurst, who proposed a method of pneumatic
+transmission of small parcels and of letters, which is now
+in use, and, 15 years later, a railroad to take the place of
+that of Stephenson and his coadjutors. The most successful
+of several attempts to introduce this method was that
+of Clegg &amp; Samuda, at West London, and on the London
+&amp; Croydon road, and again in Ireland, between Kingstown
+and Dalkey. A line of pipe, <i>B B</i>, seen in <a href="#Fig56">Fig. 56</a>,
+two feet in diameter, was laid between the rails, <i>A A</i>, of<span class='pagenum'><a name="Page_202" id="Page_202">[202]</a></span>
+the road. This pipe was fitted with a nicely-packed piston,
+carrying a strong arm, which rose through a slit made along
+the top of the pipe, and covered by a flexible strip of
+leather, <i>E E</i>. This arm was attached to the carriage, <i>C C</i>,
+to be propelled. The pressure of the atmosphere being removed,
+by the action of a powerful pump, from the side
+toward which the train was to advance, the pressure of the
+atmosphere on the opposite side drove the piston forward,
+carrying the train with it. Stephenson was convinced,
+after examining the plans of the projectors, that the scheme
+would fail, and so expressed himself. Those who favored
+it, however, had sufficient influence with capitalists to secure
+repeated trials, although each was followed by failure, and
+it was several years before the last was heard of this system.</p>
+
+<p>A considerable portion of several of the later years of
+Stephenson&#8217;s life was spent in traveling in Europe, partly
+on business and partly for pleasure. During a visit to Belgium
+in 1845, he was received everywhere, and by all<span class='pagenum'><a name="Page_203" id="Page_203">[203]</a></span>
+classes, from the king down to the humblest of his subjects,
+with such distinction as is rarely accorded even to the
+greatest men. He soon after visited Spain with Sir Joshua
+Walmsley, to report on a proposed railway from the capital
+to the Bay of Biscay. On this journey he was taken ill,
+and his health was permanently impaired. Thenceforward
+he devoted himself principally to the direction of his own
+property, which had become very considerable, and spent
+much of his time at the collieries and other works in which
+he had invested it. His son had now entirely relieved him
+of all business connected with railroads, and he had leisure
+to devote to self-improvement and social amusement. Among
+his friends he claimed Sir Robert Peel, his old acquaintance,
+now Sir William, Fairbairn, Dr. Buckland, and many others
+of the distinguished men of that time.</p>
+
+<p>In August, 1848, Stephenson was attacked with intermittent
+fever, succeeded by h&aelig;morrhage from the lungs, and
+died on the 12th of that month, at the age of sixty-six
+years, honored of all men, and secure of an undying fame.
+Soon after his death, statues were erected at Liverpool,
+London, and Newcastle, the cost of the second of which
+was defrayed by private subscriptions, including a contribution
+of about $1,500 by 3,150 workingmen&mdash;one of the
+finest tributes ever offered to the memory of a great man.</p>
+
+<p>But the noblest monument is that which he himself
+erected by the establishment of a system of education and
+protection of his working-people at Clay Cross. He made it
+a condition of employment that every employ&eacute; should contribute
+from five to twelve pence each fortnight to a fund,
+to which the works also made liberal contributions. From
+that fund it was directed that the expenses of free education
+of the children of the work-people, night-schools for those
+employed in the works, a reading-room and library, medical
+treatment, and a benevolent fund were to be defrayed.
+Music and cricket-clubs, and prize funds for the best garden,
+were also founded. The school, public hall, and the<span class='pagenum'><a name="Page_204" id="Page_204">[204]</a></span>
+church of Clay Cross, and this noble system of support, are
+together a nobler monument than any statue or similar
+structure could be.</p>
+
+<p>The character of George Stephenson was in every way
+admirable. Simple, earnest, and honorable; courageous,
+indomitable, and industrious; humorous, kind, and philanthropic,
+his memory will long be cherished, and will long
+prove an incentive to earnest effort and to the pursuit of an
+honorable fame with hundreds of the youth who, reading
+his simple yet absorbing story, as told by his biographer,
+shall in later years learn to know him.</p>
+
+<p>After the death of his father, Robert Stephenson continued,
+as he had already done for several years, to conduct
+the business of building locomotives, as well as of constructing
+railroads. The work of locomotive engine-building was
+done at Newcastle, and for many years those works were
+the principal engine-building establishment of the world.</p>
+
+<div class="figcenter"><a name="Fig57" id="Fig57"></a>
+<img src="images/illo231.png" alt="Stephenson's Locomotive" width="406" height="350" />
+<p class="caption"><span class="smcap">Fig. 57.</span>&mdash;Stephenson&#8217;s Locomotive, 1833.</p></div>
+
+<p><span class='pagenum'><a name="Page_205" id="Page_205">[205]</a></span>After their introduction on the Liverpool &amp; Manchester
+road, the engines of the firm of Robert Stephenson &amp;
+Co. were rapidly modified, until they assumed the form
+shown in <a href="#Fig57">Fig. 57</a>, which remained standard until their
+gradual increase in weight compelled the builders to place
+a larger number of wheels beneath them, and make those
+other changes which finally resulted in the creation of distinct
+types for special kinds of work. In the engine of
+1833, as shown above, the cylinders, <i>A</i>, are carried at the
+extreme forward end of the boiler, and the driving-wheels,
+<i>B</i>, are coupled directly to the connecting-rod of the engine
+and to each other. A buffer, <i>C</i>, extends in front, and the
+rear end of the boiler is formed into a rectangular fire-box,
+<i>D</i>, continuous with the shell, <i>E</i>, and the flame and gases
+pass to the connection and smoke-pipe, <i>F</i>, <i>G</i>, through a
+large number of small tubes, <i>a</i>. Steam is led to the cylinders
+by a steam-pipe, <i>H H</i>, to which it is admitted by the
+throttle-valve, <i>b</i>. A steam-dome, <i>I</i>, from which the steam
+is taken, assists by giving more steam-space far above the
+water-line, and thus furnishing dry steam. The exhaust
+steam issues with great velocity into the chimney from the
+pipe, <i>J</i>, giving great intensity of draught. The engine-driver
+stands on the platform, <i>K</i>, from which all the valves
+and handles are accessible. Feed-pumps, <i>L</i>, supply the
+boiler with water, which is drawn from the tender through
+the pipes, <i>e</i>, <i>f</i>.</p>
+
+<div class="figcenter"><a name="Fig58" id="Fig58"></a>
+<img src="images/illo233.png" alt="Stephenson Valve Gear" width="600" height="251" />
+<p class="caption"><span class="smcap">Fig. 58.</span>&mdash;The Stephenson Valve-Gear, 1833.</p></div>
+
+<p>The valve-gear was then substantially what it is to-day,
+the &#8220;Stephenson link&#8221; (<a href="#Fig58">Fig. 58</a>). On the driving-axle were
+keyed two eccentrics, <i>E</i>, so set that the motion of the one
+was adapted to driving the valve when the engine was moving
+forward, and the other was arranged to move the valve
+when running backward. The former was connected,
+through its strap and the rod, <i>B</i>, to the upper end of a
+&#8220;strap-link,&#8221; <i>A</i>, while the second was similarly connected
+with the lower end. By means of a handle, <i>L</i>, and the link,
+<i>n</i>, and its connections, including the counterweighted
+bell-crank,<span class='pagenum'><a name="Page_206" id="Page_206">[206]</a></span>
+<i>M</i>, this link could be raised or depressed, thus
+bringing the pin on the link-block, to which the valve-stem
+was connected, into action with either eccentric. Or,
+the link being set in mid-gear, the valve would cover both
+steam-ports of the cylinder, and the engine could move
+neither way. As shown, the engine is in position to run
+backward. A series of notches, <i>Z</i>, into either of which a
+catch on <i>L</i> could be dropped, enabled the driver to place
+the link where he chose. In intermediate positions, between
+mid-gear and full-gear, the motion of the valve is
+such as to produce expansion of the steam, and some gain
+in economy of working, although reducing the power of the
+engine.</p>
+
+<p>The success of the railroad and the locomotive in Great
+Britain led to its rapid introduction in other countries. In
+France, as early as 1823, M. Beaunier was authorized to
+construct a line of rails from the coal-mines of St. &Eacute;tienne
+to the Loire, using horses for the traction of his trains; and
+in 1826, MM. Seguin began a road from St. &Eacute;tienne to
+Lyons. In 1832, engines built at Lyons were substituted
+for horses on these roads, but internal agitations interrupted
+the progress of the new system in France, and, for 10 years
+after the opening of the Manchester &amp; Liverpool road,
+France remained without steam-transportation on land.</p>
+
+<p>In Belgium the introduction of the locomotive was more<span class='pagenum'><a name="Page_207" id="Page_207">[207]</a></span>
+promptly accomplished. Under the direction of Pierre
+Simon, an enterprising and well-informed young engineer,
+who had become known principally as an advocate of the
+even then familiar project of a canal across the Isthmus of
+Darien, very complete plans of railroad communication for
+the kingdom were prepared, in compliance with a decree
+dated July 31, 1834, and were promptly authorized. The
+road between Brussels and Mechlin was opened May 6,
+1837, and other roads were soon built; and the railway system
+of Belgium was the first on the Continent of Europe.</p>
+
+<p>The first German railroad worked with locomotive steam-engines
+was that between Nuremberg and F&uuml;rth, built under
+the direction of M. Denis. The other European countries
+soon followed in this rapid march of improvement.</p>
+
+<p>In the United States, public attention had been directed
+to this subject, as has already been stated, very early in the
+present century, by Evans and Stevens. At that time the
+people of the United States, as was natural, closely watched
+every important series of events in the mother-country;
+and so remarkable and striking a change as that which was
+taking place in the time of Stephenson, in methods of communication
+and transportation, could not fail to attract
+general attention and awaken universal interest.</p>
+
+<p>Notwithstanding the success of the early experiments of
+Evans and others, and in spite of the statesmanlike arguments
+of Stevens and Dearborn, and the earnest advocacy
+of the plan by all who were familiar with the revelations
+which were daily made of the power and capabilities of the
+steam-engine, it was not until after the opening of the Manchester
+&amp; Liverpool road that any action was taken looking
+to the introduction of the locomotive. Colonel John
+Stevens, in 1825, had built a small locomotive, which he
+had placed on a circular railway before his house&mdash;now
+Hudson Terrace&mdash;at Hoboken, to prove that his statements
+had a basis of fact. This engine had two &#8220;lantern&#8221; tubular
+boilers, each composed of small iron tubes, arranged<span class='pagenum'><a name="Page_208" id="Page_208">[208]</a></span>
+vertically in circles about the furnaces.<a name="FNanchor_55_55" id="FNanchor_55_55"></a><a
+href="#Footnote_55_55" class="fnanchor">[55]</a> This exhibition
+had no other effect, however, than to create some interest
+in the subject, which aided in securing a rapid adoption of
+the railroad when once introduced.</p>
+
+<p>The first line of rails in the New England States is
+said to have been laid down at Quincy, Mass., from the
+granite quarry to the Neponset River, three miles away, in
+1826 and 1827. That between the coal-mines of Mauch
+Chunk, Pa., and the river Lehigh, nine miles distant, was
+built in 1827. In the following year the Delaware &amp;
+Hudson Canal Company built a railroad from their mines
+to the termination of the canal at Honesdale. These roads
+were worked either by gravity or by horses and mules.</p>
+
+<p>The competition at Rainhill, on the Liverpool and Manchester
+Railroad, had been so widely advertised, and promised
+to afford such conclusive evidence relative to the value
+of the locomotive steam-engine and the railroad, that engineers
+and others interested in the subject came from all
+parts of the world to witness the trial. Among the strangers
+present were Mr. Horatio Allen, then chief-engineer of
+the Delaware &amp; Hudson Canal Company, and Mr. E. L.
+Miller, a resident of Charleston, S. C., who went from the
+United States for the express purpose of seeing the new
+machines tested.</p>
+
+<p>Mr. Allen had been authorized to purchase, for the company
+with which he was connected, three locomotives and
+the iron for the road, and had already shipped one engine
+to the United States, and had set it at work on the road.
+This engine was received in New York in May, 1829, and
+its trial took place in August at Honesdale, Mr. Allen himself
+driving the engine. But the track proved too light for
+the locomotive, and it was laid up and never set at regular
+work. This engine was called the &#8220;Stourbridge Lion&#8221;; it
+was built by Foster, Rastrick &amp; Co., of Stourbridge, England.<span class='pagenum'><a name="Page_209" id="Page_209">[209]</a></span>
+During the summer of the next year, a small experimental
+engine, which was built in 1829 by Peter Cooper,
+of New York, was successfully tried on the Baltimore &amp;
+Ohio Railroad, at Baltimore, making 13 miles in less than
+an hour, and moving, at some points on the road, at the rate
+of 18 miles an hour. One carriage carrying 36 passengers
+was attached. This was considered a working-model only,
+and was rated at one horse-power.</p>
+
+<p>Ross Winans, writing of this trial of Cooper&#8217;s engine,
+makes a comparison with the work done by Stephenson&#8217;s
+&#8220;Rocket,&#8221; and claims a decided superiority for the former.
+He concluded that the trial established fully the practicability
+of using locomotives on the Baltimore &amp; Ohio road
+at high speeds, and on all its curves and heavy gradients,
+without inconvenience or danger.</p>
+
+<p>This engine had a vertical tubular boiler, and the draught
+was urged, like that of the &#8220;Novelty&#8221; at Liverpool, by mechanical
+means&mdash;a revolving fan. The single steam-cylinder
+was 3<span class="enum">1</span>&#8725;<span class="denom">4</span>
+inches in diameter, and the stroke of piston 14<span class="enum">1</span>&#8725;<span class="denom">2</span>
+inches. The wheels were 30 inches in diameter, and connected
+to the crank-shaft by gearing. The engine, on the
+trial, worked up to 1.43 horse-power, and drew a gross
+weight of 4<span class="enum">1</span>&#8725;<span class="denom">2</span> tons. Mr. Cooper, unable to find such tubes
+as he needed for his boiler, used gun-barrels. The whole
+machine weighed less than a ton.</p>
+
+<p>Messrs. Davis &amp; Gartner, a little later, built the &#8220;York&#8221;
+for this road&mdash;a locomotive having also a vertical boiler, of
+very similar form to the modern steam fire-engine boiler, 51
+inches in diameter, and containing 282 fire-tubes, 16 inches
+long, and tapering from 1<span class="enum">1</span>&#8725;<span class="denom">2</span> inches diameter at the bottom
+to 1<span class="enum">1</span>&#8725;<span class="denom">4</span> at the top, where the gases were discharged through
+a combustion-chamber into a steam-chimney. This engine
+weighed 3<span class="enum">1</span>&#8725;<span class="denom">2</span> tons.</p>
+
+<div class="figcenter"><a name="Fig59" id="Fig59"></a>
+<img src="images/illo237.png" alt="The 'Atlantic'" width="372" height="350" />
+<p class="caption"><span class="smcap">Fig. 59.</span>&mdash;The &#8220;Atlantic,&#8221; 1882.</p></div>
+
+<p>They subsequently built several &#8220;grasshopper&#8221; engines
+(<a href="#Fig59">Fig. 59</a>), some of which ran many years, doing good work,
+and one or two of which are still in existence. The first&mdash;the<span class='pagenum'><a name="Page_210" id="Page_210">[210]</a></span>
+&#8220;Atlantic&#8221;&mdash;was set at work in September, 1832, and
+hauled 50 tons from Baltimore 40 miles, over gradients having
+a maximum rise of 37 feet to the mile, and on curves
+having a minimum radius of 400 feet, at the rate of 12 to
+15 miles an hour. This engine weighed 6<span class="enum">1</span>&#8725;<span class="denom">2</span> tons, carried 50
+pounds of steam&mdash;a pressure then common on both continents
+&mdash;and burned a ton of anthracite coal on the round trip.
+The blast was secured by a fan, and the valve-gear was
+worked by cams instead of eccentrics. This engine made
+the round trip at a cost of $16, doing the work of 42 horses,
+which had cost $33 per trip. The engine cost $4,500, and
+was designed by Phineas Davis, assisted by Ross Winans.</p>
+
+<p>Mr. Miller, on his return from the Liverpool &amp; Manchester
+trial, ordered a locomotive for the Charleston &amp;
+Hamburg Railroad from the West Point Foundery. This<span class='pagenum'><a name="Page_211" id="Page_211">[211]</a></span>
+engine was guaranteed by Mr. Miller to draw three times
+its weight at the rate of 10 miles an hour. It was built
+during the summer of 1830, from the plans of Mr. Miller,
+and reached Charleston in October. The trials were made
+in November and December.</p>
+
+<div class="figcenter"><a name="Fig60" id="Fig60"></a>
+<img src="images/illo238.png" alt="The 'Best Friend'" width="424" height="350" />
+<p class="caption"><span class="smcap">Fig. 60.</span>&mdash;The &#8220;Best Friend,&#8221; 1830.</p></div>
+
+<p>This engine (<a href="#Fig60">Fig. 60</a>) had a vertical tubular boiler, in
+which the gases rose through a very high fire-box, into
+which large numbers of rods projected from the sides and
+top, and passed out through tubes leading them laterally
+outward into an outside jacket, through which they rose to
+the chimney. The steam-cylinders were two in number,
+8 inches in diameter and of 16 inches stroke, inclined so as
+to connect with the driving-axle. The four wheels were all
+of the same size, 4<span class="enum">1</span>&#8725;<span class="denom">2</span> feet in diameter, and connected by
+coupling-rods. The engine weighed 4<span class="enum">1</span>&#8725;<span class="denom">2</span> tons. The &#8220;Best
+Friend,&#8221; as it was called, did excellent work until June,
+1831, when the explosion of the boiler, in consequence of the
+recklessness of the fireman, unexpectedly closed its career.</p>
+
+<div class="figcenter"><a name="Fig61" id="Fig61">
+</a><img src="images/illo239.png" alt="The 'West Point'" width="369" height="350" />
+<p class="caption"><span class="smcap">Fig. 61.</span>&mdash;The &#8220;West Point,&#8221; 1831.</p></div>
+
+<p><span class='pagenum'><a name="Page_212" id="Page_212">[212]</a></span>A second
+engine (<a href="#Fig61">Fig. 61</a>) was built for this road, at the
+West Point Foundery, from plans furnished by Horatio
+Allen, and was received and set at work early in the spring
+of 1831. The engine, called the &#8220;West Point,&#8221; had a horizontal
+tubular boiler, but was in other respects very similar
+to the &#8220;Best Friend.&#8221; It is said to have done very good
+work.</p>
+
+<p>The Mohawk &amp; Hudson Railroad ordered an engine
+at about this time, also, of the West Point Foundery, and
+the trials, made in July and August, 1831, proved thoroughly
+successful.</p>
+
+<p>This engine, the &#8220;De Witt Clinton,&#8221; was contracted for
+by John B. Jervis, and fitted up by David Matthew. It
+had two steam-cylinders, each 5<span class="enum">1</span>&#8725;<span class="denom">2</span> inches in diameter and 16
+inches stroke of piston. The connecting-rods were directly<span class='pagenum'><a name="Page_213" id="Page_213">[213]</a></span>
+attached to a cranked axle, and turned four coupled wheels
+4<span class="enum">1</span>&#8725;<span class="denom">2</span> feet in diameter. These wheels had cast-iron hubs and
+wrought-iron spokes and tires. The tubes were of copper,
+2<span class="enum">1</span>&#8725;<span class="denom">2</span> inches in diameter and 6 feet long. The engine weighed
+3<span class="enum">1</span>&#8725;<span class="denom">2</span> tons, and hauled 5 cars at the rate of 30 miles an hour.</p>
+
+<div class="figcenter"><a name="Fig62" id="Fig62"></a>
+<img src="images/illo240.png" alt="The 'South Carolina'" width="450" height="275" />
+<p class="caption"><span class="smcap">Fig. 62.</span>&mdash;The &#8220;South Carolina,&#8221; 1831.</p></div>
+
+<p>Another engine, the &#8220;South Carolina&#8221; (<a href="#Fig62">Fig. 62</a>), was
+designed by Horatio Allen for the South Carolina Railroad,
+and completed late in the year 1831. This was the first
+eight-wheeled engine, and the prototype, also, of a peculiar
+and lately-revived form of engine.</p>
+
+<p>In the summer of 1832, an engine built by Messrs. Davis
+&amp; Gartner, of York, Pa., was put on the Baltimore &amp;
+Ohio road, which at times attained a speed, unloaded, of 30
+miles an hour. The engine weighed 3<span class="enum">1</span>&#8725;<span class="denom">2</span> tons, and drew,
+usually, 4 cars, weighing altogether 14 tons, from Baltimore
+to Ellicott&#8217;s Mills, a distance of 13 miles, in the schedule-time,
+one hour.</p>
+
+<p>Horatio Allen&#8217;s engine on the South Carolina Railroad
+is said to have been the first eight-wheeled engine ever built.</p>
+
+<p>It was at about the time of which we are now writing
+that the first locomotive was built of what is now distinctively<span class='pagenum'><a name="Page_214" id="Page_214">[214]</a></span>
+known as the American type&mdash;an engine with a
+&#8220;truck&#8221; or &#8220;bogie&#8221; under the forward end of the boiler.
+This was the &#8220;American&#8221; No. 1, built at the West Point
+Foundery, from plans furnished by John B. Jervis, Chief
+Engineer, for the Mohawk &amp; Hudson Railroad. Ross
+Winans had already (1831) introduced the passenger-car
+with swiveling trucks.<a name="FNanchor_56_56" id="FNanchor_56_56"></a><a href="#Footnote_56_56"
+class="fnanchor">[56]</a> It was completed in August, 1832,
+and is said by Mr. Matthew to have been an extremely fast
+and smooth-running engine. A mile a minute was repeatedly
+attained, and it is stated by the same authority,<a name="FNanchor_57_57"
+id="FNanchor_57_57"></a><a href="#Footnote_57_57" class="fnanchor">[57]</a> that
+a speed of 80 miles an hour was sometimes made over a
+single mile. This engine had cylinders 9<span class="enum">1</span>&#8725;<span class="denom">2</span> inches diameter,
+16 inches stroke of piston, two pairs of driving-wheels,
+coupled, 5 feet in diameter each; and the truck had four
+33-inch wheels. The boiler contained tubes 3 inches in diameter,
+and its fire-box was 5 feet long and 2 feet 10 inches
+wide. Robert Stephenson &amp; Co. subsequently built a similar
+engine, from the plans of Mr. Jervis, and for the same
+road. It was set at work in 1833. In both engines the
+driving-wheels were behind the fire-box. This engine is
+another illustration of the fact&mdash;shown by the description
+already given of other and earlier engines&mdash;that the independence
+of the American mechanic, and the boldness and
+self-confidence which have to the present time distinguished
+him, were among the earliest of the fruits of our political
+independence and freedom.</p>
+
+<p>These American engines were all designed to burn anthracite
+coal. The English locomotives all burned bituminous
+coal.</p>
+
+<div class="figcenter"><a name="Fig63" id="Fig63"></a>
+<img src="images/illo242.png" alt="Stevens Rail" width="600" height="162" />
+<p class="caption"><span class="smcap">Fig. 63.</span>&mdash;The &#8220;Stevens&#8221; Rail. Enlarged Section.</p></div>
+
+<p>Robert L. Stevens, the President and Engineer of the
+Camden &amp; Amboy Railroad, and a distinguished son of
+Colonel John Stevens, of Hoboken, was engaged, at the
+time of the opening of the Liverpool &amp; Manchester Railroad,<span class='pagenum'><a name="Page_215" id="Page_215">[215]</a></span>
+in the construction of the Camden &amp; Amboy Railroad.
+It was here that the first of the now standard form
+of <i>T</i>-rail was laid down. It was of malleable iron, and of
+the form shown in the accompanying figure. It was designed
+by Mr. Stevens, and is known in the United States
+as the &#8220;Stevens&#8221; rail. In Europe, where it was introduced
+some years afterward, it is sometimes called the &#8220;Vignolles&#8221;
+rail. He purchased an engine of the Stephensons soon after
+the trial at Rainhill, and this engine, the &#8220;John Bull,&#8221; was
+set up on the then uncompleted road at Bordentown, in the
+year 1831. Its first public trial was made in November of
+that year. The road was opened for traffic, from end to
+end, two years later. This engine had steam-cylinders 9
+inches in diameter, 2 feet stroke of piston, one pair of drivers
+4<span class="enum">1</span>&#8725;<span class="denom">2</span> feet in diameter, and weighed 10 tons. This engine,
+and that built by Phineas Davis for the Baltimore &amp; Ohio
+Railroad, were exhibited at the Centennial Exhibition at
+Philadelphia, in the year 1876.</p>
+
+<div class="figcenter"><a name="Fig64" id="Fig64"></a>
+<img src="images/illo243.png" alt="'Old Ironsides'" width="450" height="293" />
+<p class="caption"><span class="smcap">Fig. 64.</span>&mdash;&#8220;Old Ironsides,&#8221; 1832.</p></div>
+
+<p>Engines supplied to the Camden &amp; Amboy Railroad
+subsequent to 1831 were built from the designs of Robert
+L. Stevens, in the shop of the Messrs. Stevens, at
+Hoboken. The other principal roads of the country, at
+first, very generally purchased their engines of the Baldwin
+Locomotive Works, then a small shop owned by Matthias
+W. Baldwin. Baldwin&#8217;s first engine was a little model
+built for Peale&#8217;s Museum, to illustrate to the visitors of that
+then well-known place of entertainment the character of the<span class='pagenum'><a name="Page_216" id="Page_216">[216]</a></span>
+new motor, the success of which, at Rainhill, had just then
+excited the attention of the world. This was in 1831, and
+the successful working of this little model led to his receiving
+an order for an engine from the Philadelphia &amp;
+Germantown Railroad. Mr. Baldwin, after studying the
+new engine of the Camden &amp; Amboy road, made his plans,
+and built an engine (<a href="#Fig64">Fig. 64</a>), completing it in the autumn
+of 1832, and setting it in operation November 23d of that
+year. It was kept at work on that line of road for a period
+of 20 years or more. This engine was of Stephenson&#8217;s
+&#8220;Planet&#8221; class, mounted on two driving-wheels 4<span class="enum">1</span>&#8725;<span class="denom">2</span> feet in
+diameter each, and two separate wheels of the same size,
+uncoupled. The steam-cylinders were 9<span class="enum">1</span>&#8725;<span class="denom">2</span> inches in diameter,
+18 inches stroke of piston, and were placed horizontally
+on each side of the smoke-box. The boiler, 2<span class="enum">1</span>&#8725;<span class="denom">2</span> feet in diameter,
+contained 72 copper tubes 1<span class="enum">1</span>&#8725;<span class="denom">2</span> inches in diameter and 7
+feet long. The engine cost the railroad company $3,500.
+On the trial, steam was raised in 20 minutes, and the maximum
+speed noted was 28 miles an hour. The engine subsequently
+attained a speed of over 30 miles. In 1834, Mr.<span class='pagenum'><a name="Page_217" id="Page_217">[217]</a></span>
+Baldwin completed for Mr. E. L. Miller, of Charleston, a
+six-wheeled engine, the &#8220;E. L. Miller&#8221; (<a href="#Fig65">Fig. 65</a>), with cylinders
+10 inches in diameter and 16 inches stroke of piston.
+He made the boiler of this engine of a form which remained
+standard many years, with a high dome over the fire-box.
+At about the same time, he built the &#8220;Lancaster,&#8221; an engine
+resembling the &#8220;Miller,&#8221; for the State road to Columbia,
+and several others were soon contracted for and built. By
+the end of 1834, 5 engines had been built by him, and the
+construction of locomotive-engines had become one of the
+leading and most promising industries of the United States.
+Mr. William Norris established a shop in Philadelphia in
+1832, which he gradually enlarged until it, like the Baldwin
+Works, became a large establishment. He usually
+built a six-wheeled engine, with a leading-truck or bogie,
+and placed his driving-wheels in front of the fire-box.</p>
+
+<div class="figcenter"><a name="Fig65" id="Fig65"></a>
+<img src="images/illo244.png" alt="The 'E.L. Miller'" width="400" height="287" />
+<p class="caption"><span class="smcap">Fig. 65.</span>&mdash;The &#8220;E. L. Miller,&#8221; 1834.</p></div>
+
+<p>At this time the English locomotives were built to carry
+60 pounds of steam. The American builders adopted pressures
+of 120 to 130 pounds per square inch, the now generally
+standard pressures throughout the world. In the years
+1836 and 1837, Baldwin built 80 engines. They were of
+three classes: 1st, with cylinders 12<span class="enum">1</span>&#8725;<span class="denom">2</span> inches in diameter
+and of 16 inches stroke, weighing 12 tons; 2d, with cylinders<span class='pagenum'><a name="Page_218" id="Page_218">[218]</a></span>
+12 by 16, and a weight of 10<span class="enum">1</span>&#8725;<span class="denom">2</span> tons; and 3d, engines
+weighing 9 tons, and having steam-cylinders of 10<span class="enum">1</span>&#8725;<span class="denom">2</span> inches
+diameter and of the same stroke. The driving-wheels were
+usually 4<span class="enum">1</span>&#8725;<span class="denom">2</span> feet in diameter, and the cylinder &#8220;inside-connected&#8221;
+to cranked axles. A few &#8220;outside-connected&#8221; engines
+were made, this plan becoming generally adopted at
+a later period.</p>
+
+<p>The railroads of the United States were very soon supplied
+with locomotive-engines built in America. In the
+year 1836, William Norris, who had two years before purchased
+the interest of Colonel Stephen H. Long, an army-officer
+who patented and built locomotives of his own design,
+built the &#8220;George Washington,&#8221; and set it at work.
+This engine, weighing 14,400 pounds, drew 19,200 pounds
+up an incline 2,800 feet long, rising 369 feet to the mile, at
+the speed of 15<span class="enum">1</span>&#8725;<span class="denom">2</span> miles an hour. This showed an adhesion
+not far from one-third the weight on the driving-wheels.
+This was considered a very wonderful performance, and it
+produced such an impression at the time, that several copies
+of the &#8220;George Washington&#8221; were made, on orders from
+British railroads, and the result was the establishment of
+the reputation of the locomotive-engine builders of the
+United States upon a foundation which has never since
+failed them. The engine had Jervis&#8217;s forward-truck, now
+always seen under standard engines, which had already been
+placed under railroad-cars by Ross Winans.</p>
+
+<p>In New England, the Locks &amp; Canals Company, of
+Lowell, began building engines as early as 1834, copying
+the Stephenson engine. Hinckley &amp; Drury, of Boston,
+commenced building an outside-connected engine in 1840,
+and their successors, the Boston Locomotive Works, became
+the largest manufacturing establishment of the kind in New
+England. Two years later, Ross Winans, the Baltimore
+builder, introduced some of his engines upon Eastern railroads,
+fitting them with upright boilers, and burning anthracite
+coal.</p>
+
+<p><span class='pagenum'><a name="Page_219" id="Page_219">[219]</a></span>The changes which have been outlined produced the
+now typical American locomotive. It was necessarily given
+such form that it would work safely and efficiently on rough,
+ill-ballasted, and often sharply-winding tracks; and thus it
+soon became evident that the two pairs of coupled driving-wheels,
+carrying two-thirds the weight of the whole engine,
+the forward-truck, and the system of &#8220;equalizing&#8221; suspension-bars,
+by which the weight is distributed fairly among
+all the wheels, whatever the position of the engine, or whatever
+the irregularity of the track, made it the very best of
+all known types of locomotive for the railroads of a new
+country. Experience has shown it equally excellent on the
+smoothest and best of roads. The &#8220;cow-catcher,&#8221; placed
+in front to remove obstacles from the track, the bell, and
+the heavy whistle, are characteristics of the American engine
+also. The severity of winter-storms compelled the
+adoption of the &#8220;cab,&#8221; or house, and the use of wood for
+fuel led to the invention of the &#8220;spark-arrester&#8221; for that
+class of engines. The heavy grades on many roads led to
+the use of the &#8220;sand-box,&#8221; from which sand was sprinkled
+on the track, to prevent the slipping of the wheels.</p>
+
+<p>In the year 1836, the now standard chilled wheel was
+introduced for cars and trucks; the single eccentric, which
+had been, until then, used on Baldwin engines, was displaced
+by the double eccentric, with hooks in place of the
+link; and, a year later, the iron frame took the place of
+the previously-used wooden frame on all engines.</p>
+
+<p>The year 1837 introduced a period of great depression
+in all branches of industry, which continued until the year
+1840, or later, and seriously checked all kinds of manufacturing,
+including the building of locomotives. On the revival
+of business, numbers of new locomotive-works were
+started, and in these establishments originated many new
+types of engine, each of the more successful of which was
+adapted to some peculiar set of conditions. This variety of
+type is still seen on nearly all of the principal roads.</p>
+
+<p><span class='pagenum'><a name="Page_220" id="Page_220">[220]</a></span>The direction of change in the construction of locomotive-engines
+at the period at which this division of the subject
+terminates is very well indicated in a letter from Robert
+Stephenson to Robert L. Stevens, dated 1833, which is
+now preserved at the Stevens Institute of Technology. He
+writes: &#8220;I am sorry that the feeling in the United States
+in favor of light railways is so general. In England we are
+making every succeeding railway stronger and more substantial.&#8221;
+He adds: &#8220;Small engines are losing ground,
+and large ones are daily demonstrating that powerful engines
+are the most economical.&#8221; He gives a sketch of his
+latest engine, weighing <i>nine tons</i>, and capable, as he states,
+of &#8220;taking 100 tons, gross load, at the rate of 16 or 17 miles
+an hour on a level.&#8221; To-day there are engines built weighing
+70 tons, and our locomotive-builders have standard sizes
+guaranteed to draw over 2,000 tons on a good and level
+track.</p>
+
+<hr class="l05" />
+<div class="colleft">
+
+<div class="footnote"><p class="left"><a name="Footnote_44_44" id="Footnote_44_44"></a><a href="#FNanchor_44_44"><span class="label">[44]</span></a> <i>Vide</i> &#8220;Theatrum Machinarum,&#8221; vol. iii., Tab. 30.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_45_45" id="Footnote_45_45"></a><a href="#FNanchor_45_45"><span class="label">[45]</span></a> Evans&#8217;s prediction is less remarkable than that of Darwin, <a href="#Darwin">elsewhere</a>
+quoted.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_46_46" id="Footnote_46_46"></a><a href="#FNanchor_46_46"><span class="label">[46]</span></a> <i>See</i> &#8220;Life of Trevithick.&#8221;</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_47_47" id="Footnote_47_47"></a><a href="#FNanchor_47_47"><span class="label">[47]</span></a> For a detailed account of the progress of steam on the highway, <i>see</i>
+&#8220;Steam on Common Roads,&#8221; etc., by Young, Holley, &amp; Fisher, London,
+1861.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_48_48" id="Footnote_48_48"></a><a href="#FNanchor_48_48"><span class="label">[48]</span></a> &#8220;Life of Trevithick.&#8221;</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_49_49" id="Footnote_49_49"></a><a href="#FNanchor_49_49"><span class="label">[49]</span></a> Printed by T. &amp; J. Swords, 160 Pearl Street, New York, 1812.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_50_50" id="Footnote_50_50"></a><a href="#FNanchor_50_50"><span class="label">[50]</span></a> &#8220;Progress of the City of New York.&#8221;</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_51_51" id="Footnote_51_51"></a><a href="#FNanchor_51_51"><span class="label">[51]</span></a> &#8220;<a href="http://www.gutenberg.org/ebooks/27710">Lives of
+George and Robert Stephenson</a>,&#8221; by Samuel Smiles. New
+York and London, 1868.</p></div>
+</div>
+
+<div class="footnote"><p class="left"><a name="Footnote_52_52" id="Footnote_52_52"></a><a href="#FNanchor_52_52"><span class="label">[52]</span></a> <i>Vide</i> &#8220;A Description of the Safety-Lamp invented by George Stephenson,&#8221;
+etc., London, 1817.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_53_53" id="Footnote_53_53"></a><a href="#FNanchor_53_53"><span class="label">[53]</span></a> The American chilled wheel of cast-iron, a better wheel than that above
+described, has never been generally and successfully introduced in Europe.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_54_54" id="Footnote_54_54"></a><a href="#FNanchor_54_54"><span class="label">[54]</span></a> Smiles.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_55_55" id="Footnote_55_55"></a><a href="#FNanchor_55_55"><span class="label">[55]</span></a> One of these sectional boilers is still preserved in the lecture-room
+of the author, at the Stevens Institute of Technology.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_56_56" id="Footnote_56_56"></a><a href="#FNanchor_56_56"><span class="label">[56]</span></a> &#8220;History of the First Locomotives in America,&#8221; Brown.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_57_57" id="Footnote_57_57"></a><a href="#FNanchor_57_57"><span class="label">[57]</span></a> &#8220;Ross Winans <i>vs.</i>
+The Eastern Railroad Company&mdash;Evidence.&#8221; Boston, 1854.</p></div>
+
+<hr class="l05" />
+
+<div class="figcenter"><img src="images/illo247.png" alt="Ornament" width="250" height="239" /></div>
+
+<hr class="c40" /><p class='pagenum'><a name="Page_221" id="Page_221">[221]</a></p>
+<h2><a name="CHAPTER_V" id="CHAPTER_V"></a>CHAPTER V.</h2>
+
+<h3><i>THE MODERN STEAM-ENGINE.</i></h3>
+
+<hr class="c05" />
+<div class="blockquot"><p>&#8220;Voil&agrave; la plus merveilleuse de toutes les Machines; le M&eacute;canisme ressemble
+&agrave; celui des animaux. La chaleur est le principe de son mouvement;
+il se fait dans ses diff&eacute;rens tuyaux une circulation, comme celle du sang
+dans les veines, ayant des valvules qui s&#8217;ouvrent et se ferment &agrave; propos;
+elles se nourrit, s&#8217;&eacute;vacue d&#8217;elle m&ecirc;me dans les temps r&eacute;gl&eacute;s, et tire de son travail
+tout ce qu&#8217;il lui faut pour subsister. Cette Machine a pris sa naissance
+en Angleterre, et toutes les Machines &agrave; feu qu&#8217;on a construites ailleurs
+que dans la Grande Br&eacute;tagne ont &eacute;t&eacute; ex&eacute;cut&eacute;es par des
+Anglais.&#8221;&mdash;<span class="smcap">Belidor.</span></p></div>
+<hr class="c05" />
+
+<h4><span class="smcap">The Second Period of Application&mdash;1800-1850 (continued).
+The Steam-Engine Applied to Ship-Propulsion.</span></h4>
+<hr class="c05" />
+
+<p>Among the most obviously important and most inconceivably
+fruitful of all the applications of steam which marked
+the period we are now studying, is that of the steam-engine
+to the propulsion of vessels. This direction of application
+has been that which has, from the earliest period in
+the history of the steam-engine, attracted the attention of
+the political economist and the historian, as well as the
+mechanician, whenever a new improvement, or the revival
+of an old device, has awakened a faint conception of the
+possibilities attendant upon the introduction of a machine
+capable of making so great a force available. The realization
+of the hopes, the prophecies, and the aspirations of
+earlier times, in the modern marine steam-engine, may be
+justly regarded as the greatest of all the triumphs of mechanical
+engineering. Although, as has already been stated,<span class='pagenum'><a name="Page_222" id="Page_222">[222]</a></span>
+attempts were made at a very early period to effect this
+application of steam-power, they were not successful, and
+the steamship is a product of the present century. No
+such attempts were commercially successful until after the
+time of Newcomen and Watt, and at the commencement of
+the nineteenth century. It is, indeed, but a few years since
+the passage across the Atlantic was frequently made in
+sailing-vessels, and the dangers, the discomforts, and the
+irregularities of their trips were most serious. Now, hardly
+a day passes that does not see several large and powerful
+steamers leaving the ports of New York and Liverpool to
+make the same voyages, and their passages are made with
+such regularity and safety, that travelers can anticipate with
+confidence the time of their arrival at the termination of
+their voyage to a day, and can cross with safety and with
+comparative comfort even amid the storms of winter. Yet all
+that we to-day see of the extent and the efficiency of steam-navigation
+has been the work of the present century, and it
+may well excite our wonder and our admiration.</p>
+
+<p>The history of this development of the use of steam-power
+illustrates most perfectly that process of growth of
+this invention which has been already referred to; and
+we can here trace it, step by step, from the earliest and
+rudest devices up to those most recent and most perfect designs
+which represent the most successful existing types of
+the heat-engine&mdash;whether considered with reference to its
+design and construction, or as the highest application of
+known scientific principles&mdash;that have yet been seen in even
+the present advanced state of the mechanic arts.</p>
+
+<p>The paddle-wheel was used as a substitute for oars at a
+very early date, and a description of paddle-wheels applied
+to vessels, curiously illustrated by a large wood-cut, may be
+found in the work of Fammelli, &#8220;De l&#8217;artificioses machines,&#8221;
+published in old French in 1588. Clark<a name="FNanchor_58_58" id="FNanchor_58_58"></a><a
+href="#Footnote_58_58" class="fnanchor">[58]</a> quotes from<span class='pagenum'><a name="Page_223" id="Page_223">[223]</a></span>
+Ogilby&#8217;s edition of the &#8220;Odyssey&#8221; a stanza which reads
+like a prophecy, and almost awakens a belief that the
+great poet had a knowledge of steam-vessels in those early
+times&mdash;a thousand years before the Christian era. The
+prince thus addresses Ulysses:</p>
+
+<div class="poem"><div class="stanza">
+<span class="i0">&#8220;We use nor Helm nor Helms-man. Our tall ships<br /></span>
+<span class="i2">Have Souls, and plow with Reason up the deeps;<br /></span>
+<span class="i2">All cities, Countries know, and where they list,<br /></span>
+<span class="i2">Through billows glide, veiled in obscuring Mist;<br /></span>
+<span class="i2">Nor fear they Rocks, nor Dangers on the way.&#8221;<br /></span>
+</div></div>
+
+<p><a href="http://www.gutenberg.org/ebooks/3160">Pope&#8217;s translation</a><a name="FNanchor_59_59" id="FNanchor_59_59"></a><a
+href="#Footnote_59_59" class="fnanchor">[59]</a> furnishes the following rendering of
+Homer&#8217;s prophecy:</p>
+
+<div class="poem"><div class="stanza">
+<span class="i0">&#8220;So shalt thou instant reach the realm assigned,<br /></span>
+<span class="i2">In wondrous ships, self-moved, instinct with mind;<br /></span>
+<span class="i2">...<br /></span>
+<span class="i2">Though clouds and darkness veil the encumbered sky,<br /></span>
+<span class="i2">Fearless, through darkness and through clouds they fly.<br /></span>
+<span class="i2">Though tempests rage, though rolls the swelling main,<br /></span>
+<span class="i2">The seas may roll, the tempests swell in vain;<br /></span>
+<span class="i2">E&#8217;en the stern god that o&#8217;er the waves presides,<br /></span>
+<span class="i2">Safe as they pass and safe repass the tide,<br /></span>
+<span class="i2">With fury burns; while, careless, they convey<br /></span>
+<span class="i2">Promiscuous every guest to every bay.&#8221;<br /></span>
+</div></div>
+
+<p>It is stated that the Roman army under Claudius Caudex
+was taken across to Sicily in boats propelled by paddle-wheels
+turned by oxen. Vulturius gives pictures of such
+vessels.</p>
+
+<p>This application of the force of steam was very possibly
+anticipated 600 years ago by Roger Bacon, the learned
+Franciscan monk, who, in an age of ignorance and intellectual
+torpor, wrote:</p>
+
+<p>&#8220;I will now mention some wonderful works of art and
+nature, in which there is nothing of magic, and which magic<span class='pagenum'><a name="Page_224" id="Page_224">[224]</a></span>
+could not perform. Instruments may be made by which
+the largest ships, with only one man guiding them, will be
+carried with greater velocity than if they were full of sailors,&#8221;
+etc., etc.</p>
+
+<p>Darwin&#8217;s <a href="#Darwin">poetical prophecy</a> was published long years
+before Watt&#8217;s engine rendered its partial fulfillment a possibility;
+and thus, for many years before even the first
+promising effort had been made, the minds of the more intelligent
+had been prepared to appreciate the invention
+when it should finally be brought forward.</p>
+
+<p>The earliest attempt to propel a vessel by steam is
+claimed by Spanish authorities, as has been stated, to have
+been made by Blasco de Garay, in the harbor of Barcelona,
+Spain, in 1543. The record, claimed as having been extracted
+from the Spanish archives at Simancas, states the
+vessel to have been of 200 tons burden, and to have been
+moved by paddle-wheels; and it is added that the spectators
+saw, although not allowed closely to inspect the apparatus,
+that one part of it was a &#8220;vessel of boiling water&#8221;;
+and it is also stated that objection was made to the use of
+this part of the machine, because of the danger of explosion.</p>
+
+<p>The account seems somewhat apocryphal, and it certainly
+led to no useful results.</p>
+
+<p>In an anonymous English pamphlet, published in 1651,
+which is supposed by Stuart to have been written by the
+Marquis of Worcester, an indefinite reference to what may
+probably have been the steam-engine is made, and it is
+there stated to be capable of successful application to propelling
+boats.</p>
+
+<p>In 1690, Papin proposed to use his piston-engine to
+drive paddle-wheels to propel vessels; and in 1707 he applied
+the steam-engine, which he had proposed as a pumping-engine,
+to driving a model boat on the Fulda at Cassel.
+In this trial he used the arrangement of which a sketch has
+been shown, his pumping-engine forcing up water to turn a
+water-wheel, which, in turn, was made to drive the paddles.<span class='pagenum'><a name="Page_225" id="Page_225">[225]</a></span>
+An account of his experiments is to be found in manuscript
+in the correspondence between Leibnitz and Papin, preserved
+in the Royal Library at Hanover. Professor Joy
+found there the following letter:<a name="FNanchor_60_60" id="FNanchor_60_60"></a><a
+href="#Footnote_60_60" class="fnanchor">[60]</a></p>
+
+<div class="blockquot"><p>&#8220;Dionysius Papin, Councillor and Physician to his Royal Highness the
+Elector of Cassel, also Professor of Mathematics at Marburg, is about to
+dispatch a vessel of singular construction down the river Weser to Bremen.
+As he learns that all ships coming from Cassel, or any point on the Fulda,
+are not permitted to enter the Weser, but are required to unload at M&uuml;nden,
+and as he anticipates some difficulty, although those vessels have a different
+object, his own not being intended for freight, he begs most humbly
+that a gracious order be granted that his ship may be allowed to pass unmolested
+through the Electoral domain; which petition I most humbly support.</p>
+
+<p class="smcap right">G. W. Leibnitz.</p>
+
+<p>&#8220;<span class="smcap">Hanover</span>, <i>July 13, 1707</i>.&#8221;</p></div>
+
+<p>This letter was returned to Leibnitz, with the following
+indorsement:</p>
+
+<div class="blockquot"><p>&#8220;The Electoral Councillors have found serious obstacles in the way of
+granting the above petition, and, without giving their reasons, have directed
+me to inform you of their decision, and that, in consequence, the request is
+not granted by his Electoral Highness.</p>
+
+<p class="smcap right">H. Reiche.</p>
+
+<p>&#8220;<span class="smcap">Hanover</span>, <i>July 25, 1707</i>.&#8221;</p></div>
+
+<p>This failure of Papin&#8217;s petition was the death-blow to
+his effort to establish steam-navigation. A mob of boatmen,
+who thought they saw in the embryo steamship the
+ruin of their business, attacked the vessel at night, and utterly
+destroyed it. Papin narrowly escaped with his life,
+and fled to England.</p>
+
+<p>In the year 1736, Jonathan Hulls took out an English
+patent for the use of a steam-engine for ship-propulsion,
+proposing to employ his steamboat in towing. In 1737 he
+published a well-written pamphlet, describing this apparatus,
+which is shown in <a href="#Fig66">Fig. 66</a>, a reduced fac-simile of
+the plate accompanying his paper.</p>
+
+<p><span class='pagenum'><a name="Page_226" id="Page_226">[226]</a></span>He proposed using the Newcomen engine, fitted with a
+counterpoise-weight and a system of ropes and grooved
+wheels, which, by a peculiar ratchet-like action, gave a continuous
+rotary motion. His vessel was to have been used
+as a tow-boat. He says, in his description: &#8220;In some convenient
+part of the Tow-boat there is placed a Vessel about
+two-3rds full of water, with the Top closed; and this Vessel
+being kept Boiling, rarifies the Water into a Steam, this
+Steam being convey&#8217;d thro&#8217; a large pipe into a cylindrical
+Vessel, and there condensed, makes a Vacuum, which causes
+the weight of the atmosphere to press down on this Vessel,
+and so presses down a Piston that is fitted into this Cylindrical
+Vessel, in the same manner as in Mr. Newcomen&#8217;s
+Engine, with which he raises Water by Fire.</p>
+
+<div class="figcenter"><a name="Fig66" id="Fig66"></a>
+<img src="images/illo253.png" alt="Hulls's Steamboat" width="600" height="275" />
+<p class="caption"><span class="smcap">Fig. 66.</span>&mdash;Hulls&#8217;s Steamboat, 1736.</p></div>
+
+<p>&#8220;<i>P</i>, the Pipe coming from the Furnace to the Cylinder.
+<i>Q</i>, the Cylinder wherein the steam is condensed. <i>R</i>, the
+Valve that stops the Steam from coming into the Cylinder,
+whilst the Steam within the same is condensed. <i>S</i>, the
+Pipe to convey the condensing Water into the Cylinder.
+<i>T</i>, a cock to let in the condensing Water when the Cylinder
+is full of Steam and the Valve, <i>P</i>, is shut. <i>U</i>, a Rope fixed
+to the Piston that slides up and down in the Cylinder.</p>
+
+<p>&#8220;<i>Note.</i> This Rope, <i>U</i>, is the same Rope that goes round
+the wheel, <i>D</i>, in the machine.&#8221;</p>
+
+<p>In the large division of his plate, <i>A</i> is the chimney;
+<i>B</i><span class='pagenum'><a name="Page_227" id="Page_227">[227]</a></span>
+is the tow-boat; <i>CC</i> is the frame carrying the engine;
+<i>Da</i>, <i>D</i>, and <i>Db</i> are three wheels carrying the ropes <i>M</i>,
+<i>Fb</i>, and <i>Fa</i>, <i>M</i> being the rope <i>U</i> of his smaller figure, 30.
+<i>Ha</i> and <i>Hb</i> are two wheels on the paddle-shafts, <i>II</i>, arranged
+with pawls so that the paddle-wheel, <i>II</i>, always
+turns the same way, though the wheels <i>Ha</i> and <i>Hb</i> are
+given a reciprocating motion; <i>Fb</i> is a rope connecting
+the wheels in the vessel, <i>Db</i>, with the wheels at the stern.
+Hulls says:</p>
+
+<p>&#8220;When the Weight, <i>G</i>, is so raised, while the wheels
+<i>Da</i>, <i>D</i>, and <i>Db</i> are moving backward, the Rope <i>Fa</i> gives
+way, and the Power of the Weight, <i>G</i>, brings the Wheel
+<i>Ha</i> forward, and the Fans with it, so that the Fans always
+keep going forward, notwithstanding the Wheels <i>Da</i>, <i>D</i>,
+and <i>Db</i> move backward and forward as the Piston moves
+up and down in the Cylinder. <i>LL</i> are Teeth for a Catch
+to drop in from the Axis, and are so contrived that they
+catch in an alternate manner, to cause the Fan to move
+always forward, for the Wheel <i>Ha</i>, by the power of the
+weight, <i>G</i>, is performing his Office while the other wheel,
+<i>Hb</i>, goes back in order to fetch another stroke.</p>
+
+<p>&#8220;<i>Note.</i> The weight, <i>G</i>, must contain but half the weight
+of the Pillar of Air pressing on the Piston, because the
+weight, <i>G</i>, is raised at the same time as the Wheel <i>Hb</i> performs
+its Office, so that it is in effect two Machines acting
+alternately, by the weight of one Pillar of Air, of such a
+Diameter as the Diameter of the Cylinder is.&#8221;</p>
+
+<p>The inventor suggests the use of timber guards to protect
+the wheels from injury, and, in shallow water, the attachment
+to the paddle-shafts of cranks &#8220;to strike a Shaft
+to the Bottom of the River, which will drive the Vessel
+forward with the greater Force.&#8221; He concludes: &#8220;Thus I
+have endeavoured to give a clear and satisfactory Account
+of my New-invented Machine, for carrying Vessels out of
+and into any Port, Harbour, or River, against Wind and
+Tide, or in a Calm; and I doubt not but whoever shall<span class='pagenum'><a name="Page_228" id="Page_228">[228]</a></span>
+give himself the Trouble to peruse this Essay, will be so
+candid as to excuse or overlook any Imperfections in the
+diction or manner of writing, considering the Hand it comes
+from, if what I have imagined may only appear as plain to
+others as it has done to me, viz., That the Scheme I now
+offer is Practicable, and if encouraged will be Useful.&#8221;</p>
+
+<p>There is no positive evidence that Hulls ever put his
+scheme to the test of experiment, although tradition does
+say that he made a model, which he tried with such ill success
+as to prevent his prosecution of the experiment further;
+and doggerel rhymes are still extant which were sung
+by his neighbors in derision of his folly, as they considered
+it.</p>
+
+<p>A prize was awarded by the French Academy of Sciences,
+in 1752, for the best essay on the manner of impelling
+vessels without wind. It was given to Bernouilli, who,
+in his paper, proposed a set of vanes like those of a windmill&mdash;a
+screw, in fact&mdash;one to be placed on each side of the
+vessel, and two more behind. For a vessel of 100 tons, he
+proposed a shaft 14 feet long and 2 inches in diameter, carrying
+&#8220;eight wheels, for acting on the water, to each of
+which it&#8221; (the shaft) &#8220;is perpendicular, and forms an axis
+for them all; the wheels should be at equal distances from
+each other. Each wheel consists of 8 arms of iron, each 3
+feet long, so that the whole diameter of the wheel is 6 feet.
+Each of these arms, at the distance of 20 inches from the
+centre, carries a sheet-iron plane (or paddle) 16 inches
+square, which is inclined so as to form an angle of 60 degrees,
+both with the arbor and keel of the vessel, to which
+the arbor is placed parallel. To sustain this arbor and
+the wheels, two strong bars of iron, between 2 and 3
+inches thick, proceed from the side of the vessel at right
+angles to it, about 2<span class="enum">1</span>&#8725;<span class="denom">2</span> feet below the surface of the water.&#8221;
+He proposed similar screw-propellers at the stern, and
+suggested that they could be driven by animal or by steam-power.</p>
+
+<p><span class='pagenum'><a name="Page_229" id="Page_229">[229]</a></span>
+But a more remarkable essay is quoted by Figuier<a name="FNanchor_61_61" id="FNanchor_61_61"></a><a
+href="#Footnote_61_61" class="fnanchor">[61]</a>&mdash;the
+paper of l&#8217;Abb&eacute; Gauthier, published in the &#8220;M&eacute;moires de
+la Soci&eacute;t&eacute; Royale des Sciences et Lettres de Nancy.&#8221; Bernouilli
+had expressed the belief that the best steam-engine
+then known&mdash;that of Newcomen&mdash;was not superior to some
+other motors. Gauthier proposed to use that engine in
+the propulsion of paddle-wheels placed at the side of
+the vessel. His plan was not brought into use, but his
+paper embodied a glowing description of the advantages
+to be secured by its adoption. He states that a
+galley urged by 26 oars on a side made but 4,320 toises
+(8,420 meters), or about 5 miles, an hour, and required
+a crew of 260 men. A steam-engine, doing the same
+work, would be ready for action at all times, could
+be applied, when not driving the vessel, to raising the
+anchor, working the pumps, and to ventilating the ship,
+while the fire would also serve to cook with. The engine
+would occupy less space and weight than the men, would
+require less aliment, and that of a less expensive kind, etc.
+He would make the boiler safe against explosions by bands
+of iron; would make the fire-box of iron, with a water-filled
+ash-pit and base-plate. His injection-water was to
+come from the sea, and return by a delivery-pipe placed
+above the water-line. The chains, usually leading from the
+end of the beam to the pump-rods, were to be carried
+around wheels on the paddle-shaft, which were to be provided
+with pawls entering a ratchet, and thus the paddles,
+having been given several revolutions by the descent of the
+piston and the unwinding of the chain, were to revolve
+freely while the return-stroke was made, the chain being
+hauled down and rewound by the wheel on the shaft, the
+latter being moved by a weight. The engine was proposed
+to be of 6 feet stroke, and to make 15 strokes per minute,
+with a force of 11,000 pounds.</p>
+
+<p>A little later (1760), a Swiss clergyman, J. A. Genevois,<span class='pagenum'><a name="Page_230" id="Page_230">[230]</a></span>
+published in London a paper relating to the improvement
+of navigation,<a name="FNanchor_62_62" id="FNanchor_62_62"></a><a href="#Footnote_62_62" class="fnanchor">[62]</a>
+in which his plan was proposed of compressing
+springs by steam or other power, and applying their
+effort while recovering their form to ship-propulsion.</p>
+
+<p>It was at this time that the first attempts were made in
+the United States to solve this problem, which had begun
+to be recognized as one of the greatest which had presented
+itself to the mechanic and the engineer.</p>
+
+<p><span class="smcap">William Henry</span> was a prominent citizen of the then little
+village of Lancaster, Pa., and was noted as an ingenious
+and successful mechanic.<a name="FNanchor_63_63" id="FNanchor_63_63"></a><a href="#Footnote_63_63"
+class="fnanchor">[63]</a> He was still living at the beginning
+of the present century. Mr. Henry was the first to make
+the &#8220;rag&#8221; carpet, and was the inventor of the screw-auger.
+He was of a Scotch and North-of-Ireland family, his father,
+John Henry, and his two older brothers, Robert and James,
+having come to the United States about 1720. Robert settled,
+finally, in Virginia, and it is said that Patrick Henry,
+the patriot and orator, was of his family. The others remained
+in Chester County, Pa., where William was born,
+in 1729. He learned the trade of a gunsmith, and, driven
+from his home during the Indian war (1755 to 1760), settled
+in Lancaster.</p>
+
+<p>In the year 1760 he went to England on business, where
+his attention was attracted to the invention&mdash;then new, and
+the subject of discussion in every circle&mdash;of James Watt.
+He saw the possibility of its application to navigation and to
+driving carriages, and, on his return home, commenced the
+construction of a steam-engine, and finished it in 1763.</p>
+
+<p>Placing it in a boat fitted with paddle-wheels, he made
+a trial of the new machine on the Conestoga River, near
+Lancaster, where the craft, by some accident, sank,<a name="FNanchor_64_64" id="FNanchor_64_64"></a><a href="#Footnote_64_64"
+class="fnanchor">[64]</a> and<span class='pagenum'><a name="Page_231" id="Page_231">[231]</a></span>
+was lost. He was not discouraged by this failure, but
+made a second model, adding some improvements. Among
+the records of the Pennsylvania Philosophical Society is, or
+was, a design, presented by Henry in 1782, of one of his
+steamboats. The German traveler Sch&ouml;pff visited the
+United States in 1783, and at Mr. Henry&#8217;s house, at Lancaster,
+was shown &#8220;a machine by Mr. Henry, intended for
+the propelling of boats, etc.; &#8216;but,&#8217; said Mr. Henry, &#8216;I am
+doubtful whether such a machine would find favor with
+the public, as every one considers it impracticable against
+wind and tide;&#8217; but that such a Boat <i>will</i> come into use
+and navigate on the waters of the Ohio and Mississippi,
+he had not the least doubt of, but the time had not yet
+arrived of its being appreciated and applied.&#8221;</p>
+
+<p>John Fitch, whose experiments will presently be referred
+to, was an acquaintance and frequent visitor to the
+house of Mr. Henry, and may probably have there received
+the earliest suggestions of the importance of this application
+of steam. About 1777, when Henry was engaged in
+making mathematical and philosophical instruments, and
+the screw-auger, which at that time could only be obtained
+of him, Robert Fulton, then twelve years old, visited him,
+to study the paintings of Benjamin West, who had long
+been a friend and prot&eacute;g&eacute; of Henry. He, too, not improbably
+received there the first suggestion which afterward led
+him to desert the art to which he at first devoted himself,
+and which made of the young portrait-painter a successful
+inventor and engineer. West&#8217;s acquaintance with Henry
+had no such result. The young painter was led by his
+patron and friend to attempt historical pictures,<a name="FNanchor_65_65" id="FNanchor_65_65"></a><a
+href="#Footnote_65_65" class="fnanchor">[65]</a> and probably
+owes his fame greatly to the kindly and discerning
+mechanic. Says Galt, in his &#8220;Memoirs of Sir Benjamin
+West&#8221; (London, 1816): &#8220;Towards his old friend, William
+Henry, of Lancaster City, he always cherished the most<span class='pagenum'><a name="Page_232" id="Page_232">[232]</a></span>
+grateful affection; he was the first who urged him to attempt
+historical composition.&#8221;</p>
+
+<p>When, after the invention of Watt, the steam-engine
+had taken such shape that it could really work the propelling
+apparatus of a paddle or screw vessel, a new impetus
+was given to the work of its adaptation. In France, the
+Marquis de Jouffroy was one of the earliest to perceive that
+the improvements of Watt, rendering the engine more compact,
+more powerful, and, at the same time, more regular
+and positive in its action, had made it, at last, readily applicable
+to the propulsion of vessels. The brothers P&eacute;rier
+had imported a Watt engine from Soho, and this was attentively
+studied by the marquis,<a name="FNanchor_66_66" id="FNanchor_66_66"></a><a
+href="#Footnote_66_66" class="fnanchor">[66]</a> and its application to the
+paddle-wheels of a steam-vessel seemed to him a simple
+problem. Comte d&#8217;Auxiron and Chevalier Charles Mounin,
+of Follenai, friends and companions of Jouffroy, were
+similarly interested, and the three are said to have often
+discussed the scheme together, and to have united in devising
+methods of applying the new motor.</p>
+
+<p>In the year 1770, D&#8217;Auxiron determined to attempt the
+realization of the plans which he had conceived. He resigned
+his position in the army, prepared his plans and
+drawings, and presented them to M. Bertin, the Prime
+Minister, in the year 1771 or 1772. The Minister was favorably
+impressed, and the King (May 22, 1772) granted
+D&#8217;Auxiron a monopoly of the use of steam in river-navigation
+for 15 years, provided he should prove his plans practicable,
+and they should be so adjudged by the Academy.</p>
+
+<p>A company had been formed, the day previous, consisting
+of D&#8217;Auxiron, Jouffroy, Comte de Dijon, the Marquis
+d&#8217;Yonne, and Follenai, which advanced the requisite
+funds. The first vessel was commenced in December, 1772.
+When nearly completed, in September, 1774, the boat
+sprung a leak, and, one night, foundered at the wharf.<span class='pagenum'><a name="Page_233" id="Page_233">[233]</a></span>
+After some angry discussion, during which d&#8217;Auxiron was
+rudely, and probably unjustly, accused of bad faith, the
+company declined to advance the money needed to recover
+and complete the vessel. They were, however, compelled
+by the court to furnish it; but, meantime, d&#8217;Auxiron died
+of apoplexy, the matter dropped, and the company dissolved.
+The cost of the experiment had been something
+more than 15,000 francs.</p>
+
+<p>The heirs of d&#8217;Auxiron turned the papers of the deceased
+inventor over to Jouffroy, and the King transferred
+to him the monopoly held by the former. Follenai retained
+all his interest in the project, and the two friends soon enlisted
+a powerful adherent and patron, the Marquis Ducrest,
+a well-known soldier, courtier, and member of the Academy,
+who took an active part in the prosecution of the
+scheme. M. Jacques P&eacute;rier, the then distinguished mechanic,
+was consulted, and prepared plans, which were
+adopted in place of those of Jouffroy. The boat was built
+by P&eacute;rier, and a trial took place in 1774, on the Seine.
+The result was unsatisfactory. The little craft could hardly
+stem the sluggish current of the river, and the failure caused
+the immediate abandonment of the scheme by P&eacute;rier.</p>
+
+<p>Still undiscouraged, Jouffroy retired to his country
+home, at Baume-les-Dames, on the river Doubs. There he
+carried on his experiments, getting his work done as best
+he could, with the rude tools and insufficient apparatus of a
+village blacksmith. A Watt engine and a chain carrying
+&#8220;duck-foot&#8221; paddles were his propelling apparatus. The
+boat, which was about 14 feet long and 6 wide, was started
+in June, 1776. The duck&#8217;s-foot system of paddles proved
+unsatisfactory, and Jouffroy gave it up, and renewed his
+experiments with a new arrangement. He placed on the
+paddle-wheel shaft a ratchet-wheel, and on the piston-rod
+of his engine, which was placed horizontally in the boat,
+a double rack, into the upper and the lower parts of which
+the ratchet-wheel geared. Thus the wheels turned in the<span class='pagenum'><a name="Page_234" id="Page_234">[234]</a></span>
+same direction, whichever way the piston was moving.
+The new engine was built at Lyons in 1780, by Messrs.
+Fr&egrave;res-Jean. The new boat was about 140 feet long and
+14 feet wide; the wheels were 14 feet in diameter, their
+floats 6 feet long, and the &#8220;dip,&#8221; or depth to which they
+reached, was about 2 feet. The boat drew 3 feet of water,
+and had a total weight of about 150 tons.</p>
+
+<p>At a public trial of the vessel at Lyons, July 15, 1783,
+the little steamer was so successful as to justify the publication
+of the fact by a report and a proclamation. The
+fact that the experiment was not made at Paris was made
+an excuse on the part of the Academy for withholding its
+indorsement, and on the part of the Government for declining
+to confirm to Jouffroy the guaranteed monopoly. Impoverished
+and discouraged, Jouffroy gave up all hope of
+prosecuting his plans successfully, and re&euml;ntered the army.
+Thus France lost an honor which was already within her
+grasp, as she had already lost that of the introduction of
+the steam-engine, in the time of Papin.</p>
+
+<p>About 1785, John Fitch and James Rumsey were engaged
+in experiments having in view the application of
+steam to navigation.</p>
+
+<p>Rumsey&#8217;s experiments began in 1774, and in 1786 he
+succeeded in driving a boat at the rate of four miles an hour
+against the current of the Potomac at Shepherdstown, W.
+Va., in presence of General Washington. His method of
+propulsion has often been reinvented since, and its adoption
+urged with that enthusiasm and persistence which is a peculiar
+characteristic of inventors.</p>
+
+<p>Rumsey employed his engine to drive a great pump
+which forced a stream of water aft, thus propelling the
+boat forward, as proposed earlier by Bernouilli. This
+same method has been recently tried again by the British
+Admiralty, in a gunboat of moderate size, using a centrifugal
+pump to set in motion the propelling stream, and with
+some other modifications which are decided improvements<span class='pagenum'><a name="Page_235" id="Page_235">[235]</a></span>
+upon Rumsey&#8217;s rude arrangements, but which have not
+done much more than his toward the introduction of
+&#8220;Hydraulic or Jet Propulsion,&#8221; as it is now called.</p>
+
+<p>In 1787 he obtained a patent from the State of Virginia
+for steam-navigation. He wrote a treatise &#8220;On the Application
+of Steam,&#8221; which was printed at Philadelphia, where
+a Rumsey society was organized for the encouragement of
+attempts at steam-navigation.</p>
+
+<p>Rumsey died of apoplexy, while explaining some of his
+schemes before a London society a short time later, December
+23, 1793, at the age of fifty years. A boat, then in
+process of construction from his plans, was afterward tried
+on the Thames, in 1793, and steamed at the rate of four
+miles an hour. The State of Kentucky, in 1839, presented
+his son with a gold medal, commemorative of his father&#8217;s
+services &#8220;in giving to the world the benefit of the steamboat.&#8221;</p>
+
+<p><span class="smcap">John Fitch</span> was an unfortunate and eccentric, but very
+ingenious, Connecticut mechanic. After roaming about
+until forty years of age, he finally settled on the banks of
+the Delaware, where he built his first steamboat.</p>
+
+<p>In April, 1785, as Fitch himself states, at Neshamony,
+Bucks County, Pa., he suddenly conceived the idea that a
+carriage might be driven by steam. After considering the
+subject a few days, his attention was led to the plan of
+using steam to propel vessels, and from that time to the
+day of his death he was a persistent advocate of the introduction
+of the steamboat. At this time, Fitch says, &#8220;I
+did not know that there was a steam-engine on the earth;&#8221;
+and he was somewhat disappointed when his friend, the
+Rev. Mr. Irwin, of Neshamony, showed him a sketch of
+one in &#8220;Martin&#8217;s Philosophy.&#8221;</p>
+
+<p>Fitch&#8217;s first model was at once built, and was soon after
+tried on a small stream near Davisville. The machinery
+was made of brass, and the boat was impelled by paddle-wheels.
+A rough model of his steamboat was shown to<span class='pagenum'><a name="Page_236" id="Page_236">[236]</a></span>
+Dr. John Ewing, Provost of the University of Pennsylvania,
+who, August 20, 1785, addressed a commendatory
+letter to an ex-Member of Congress, William C. Houston,
+asking him to assist Fitch in securing the aid of the General
+Government. The latter referred the inventor, by a letter
+of recommendation, to a delegate from New Jersey, Mr.
+Lambert Cadwalader. With this, and other letters, Fitch
+proceeded to New York, where Congress then met, and
+made his application in proper form. He was unsuccessful,
+and equally so in attempting to secure aid from the
+Spanish minister, who desired that the profits should be
+secured, by a monopoly of the invention, to the King of
+Spain. Fitch declined further negotiation, determined
+that, if successful at all, the benefit should accrue to his
+own countrymen.</p>
+
+<p>In September, 1785, Fitch presented to the American
+Philosophical Society, at Philadelphia, a model in which he
+had substituted an endless chain and floats for the paddle-wheels,
+with drawings and a descriptive account of his
+scheme. This model is shown in the <a href="#Fig67">accompanying figure</a>.</p>
+
+<div class="figcenter"><a name="Fig67" id="Fig67"></a>
+<img src="images/illo263.png" alt="Fitch's Model" width="400" height="108" />
+<p class="caption"><span class="smcap">Fig. 67.</span>&mdash;Fitch&#8217;s Model, 1785.</p></div>
+
+<p>In March, 1786, Fitch was granted a patent by the
+State of New Jersey, for the exclusive right to the navigation
+of the waters of the State by steam, for 14 years. A
+month later, he was in Philadelphia, seeking a similar
+patent from the State of Pennsylvania. He did not at once
+succeed, but in a few days he had formed a company, raised
+$300, and set about finding a place in which to construct
+his engine. Henry Voight, a Dutch watchmaker, a good
+mechanic, and a very ingenious man, took an interest in the<span class='pagenum'><a name="Page_237" id="Page_237">[237]</a></span>
+company, and with him Fitch set about his work with great
+enthusiasm. After making a little model, having a steam-cylinder
+but one inch in diameter, they built a model boat
+and engine, the latter having a diameter of cylinder of three
+inches. They tried the endless chain, and other methods of
+propulsion, without success, and finally succeeded with a set
+of oars worked by the engine. In August, 1786, it was determined
+by the company to authorize the construction of a
+larger vessel; but the money was not readily obtained.
+Meantime, Fitch continued his efforts to secure a patent
+from the State, and was finally, March 28, 1787, successful.
+He also obtained a similar grant from the State of
+Delaware, in February of the same year, and from New
+York, March 19.</p>
+
+<p>Money was now subscribed more freely, and the work
+on the boat continued uninterruptedly until May, 1787,
+when a trial was made, which revealed many defects in the
+machinery. The cylinder-heads were of wood, and leaked
+badly; the piston leaked; the condenser was imperfect;
+the valves were not tight. All these defects were remedied,
+and a condenser invented by Voight&mdash;the &#8220;pipe-condenser&#8221;&mdash;was
+substituted for that defective detail as previously
+made.</p>
+
+<p>The steamboat was finally placed in working order, and
+was found capable, on trial, of making three or four miles
+an hour. But now the boiler proved to be too small to furnish
+steam steadily in sufficient quantity to sustain the
+higher speed. After some delay, and much distress on the
+part of the sanguine inventor, who feared that he might be
+at last defeated when on the very verge of success, the
+necessary changes were finally made, and a trial took place
+at Philadelphia, in presence of the members of the Convention&mdash;then
+in session at Philadelphia framing the Federal
+Constitution&mdash;August 22, 1787. Many of the distinguished
+spectators gave letters to Fitch certifying his success. Fitch
+now went to Virginia, where he succeeded in obtaining a<span class='pagenum'><a name="Page_238" id="Page_238">[238]</a></span>
+patent, November 7, 1787, and then returned to ask a patent
+of the General Government.</p>
+
+<p>A controversy with Rumsey now followed, in which
+Fitch asserted his claims to the invention of the steamboat,
+and denied that Rumsey had done more than to revive the
+scheme which Bernouilli, Franklin, Henry, Paine, and
+others, had previously proposed, and that Rumsey&#8217;s <i>steamboat</i>
+was not made until 1786.</p>
+
+<div class="figcenter"><a name="Fig68" id="Fig68"></a>
+<img src="images/illo265a.png" alt="Fitch and Voight's Boiler" width="291" height="350" />
+<p class="caption"><span class="smcap">Fig. 68.</span>&mdash;Fitch and Voight&#8217;s Boiler, 1787.</p></div>
+
+<p>The boiler adopted in Fitch&#8217;s boat of 1787 was a &#8220;pipe-boiler,&#8221;
+which he had described in a communication to the
+Philosophical Society, in September, 1785. It consisted
+(<a href="#Fig68">Fig. 68</a>) of a small water-pipe, winding backward and forward
+in the furnace, and terminating at one end at the
+point at which the feed-water was introduced, and at the
+other uniting with the steam-pipe leading to the engine.
+Voight&#8217;s condenser was similarly constructed. Rumsey
+claimed that this boiler was copied from his designs. Fitch
+brought evidence to prove that Rumsey had not built such
+a boiler until after his own.</p>
+
+<div class="figcenter"><a name="Fig69" id="Fig69"></a>
+<img src="images/illo265b.png" alt="Fitch's First Boat" width="286" height="400" />
+<p class="caption"><span class="smcap">Fig. 69.</span>&mdash;Fitch&#8217;s First Boat, 1787.</p></div>
+
+<p>Fitch&#8217;s first boat-engine had a steam-cylinder 12 inches
+in diameter. A second engine was now built (1788) with a<span class='pagenum'><a name="Page_239" id="Page_239">[239]</a></span>
+cylinder 18 inches in diameter, and a new boat. The first
+vessel was 45 feet long and 12 feet wide; the new boat was
+60 feet long and of but 8 feet breadth of beam. The first
+boat (<a href="#Fig69">Fig. 69</a>) had paddles worked at the sides, with the
+motion given the Indian paddle in propelling a canoe; in
+the second boat (<a href="#Fig70">Fig. 70</a>) they were similarly worked, but
+were placed at the stern. There were three of these paddles.
+The boat was finally finished in July, 1788, and made
+a trip to Burlington, 20 miles from Philadelphia. When
+just reaching their destination, their boiler gave out, and
+they made their return-trip to Philadelphia floating with
+the tide. Subsequently, the boat made a number of excursions
+on the Delaware River, making three or four miles an
+hour.</p>
+
+<div class="figcenter"><a name="Fig70" id="Fig70"></a>
+<img src="images/illo266.png" alt="Fitch's Second Boat" width="422" height="300" />
+<p class="caption"><span class="smcap">Fig. 70.</span>&mdash;John Fitch, 1788.</p></div>
+
+<p>Another of Fitch&#8217;s boats, in April, 1790, made seven
+miles an hour. Fitch, writing of this boat, says that &#8220;on
+the 16th of April we got our work completed, and tried
+our boat again; and, although the wind blew very fresh at
+the east, we reigned lord high admirals of the Delaware,<span class='pagenum'><a name="Page_240" id="Page_240">[240]</a></span>
+and no boat on the river could hold way with us.&#8221; In
+June of that year it was placed as a passenger-boat on a
+line from Philadelphia to Burlington, Bristol, Bordentown,
+and Trenton, occasionally leaving that route to take excursions
+to Wilmington and Chester. During this period, the
+boat probably ran between 2,000 and 3,000 miles,<a name="FNanchor_67_67"
+id="FNanchor_67_67"></a><a href="#Footnote_67_67" class="fnanchor">[67]</a> and with
+no serious accident. During the winter of 1790-&#8217;91, Fitch
+commenced another steamboat, the &#8220;Perseverance,&#8221; and
+gave considerable time to the prosecution of his claim for a
+patent from the United States. The boat was never completed,
+although he received his patent, after a long and
+spirited contest with other claimants, on the 26th of August,
+1791, and Fitch lost all hope of success. He went to
+France in 1793, hoping to obtain the privilege of building
+steam-vessels there, but was again disappointed, and worked
+his passage home in the following year.</p>
+
+<div class="figcenter"><a name="Fig71" id="Fig71"></a>
+<img src="images/illo267.png" alt="Fitch 1796" width="450" height="284" />
+<p class="caption"><span class="smcap">Fig. 71.</span>&mdash;John Fitch, 1796.</p></div>
+
+<p>In the year 1796, Fitch was again in New York City,
+experimenting with a little <i>screw</i> <a href="#Fig71">steamboat</a> on the &#8220;Collect&#8221;
+Pond, which then covered that part of the city now<span class='pagenum'><a name="Page_241" id="Page_241">[241]</a></span>
+occupied by the &#8220;Tombs,&#8221; the city prison. This little boat
+was a ship&#8217;s yawl fitted with a screw, like that adopted later
+by Woodcroft, and driven by a rudely-made engine.</p>
+
+<p>Fitch, while in the city of Philadelphia at about this
+time, met Oliver Evans, and discussed with him the probable
+future of steam-navigation, and proposed to form a
+company in the West, to promote the introduction of steam
+on the great rivers of that part of the country. He settled
+at last in Kentucky, on his land-grant, and there amused
+himself with a model steamboat, which he placed in a small
+stream near Bardstown. His death occurred there in July,
+1798, and his body still lies in the village cemetery, with
+only a rough stone to mark the spot.</p>
+
+<p>Both Rumsey and Fitch endeavored to introduce their
+methods in Great Britain; and Fitch, while urging the importance
+and the advantages of his plan, confidently stated
+his belief that the ocean would soon be crossed by steam-vessels,
+and that the navigation of the Mississippi would
+also become exclusively a steam-navigation. His reiterated
+assertion, &#8220;The day will come when some more
+powerful man will get fame and riches from my invention;
+but no one will believe that poor John Fitch can do anything
+worthy of attention,&#8221; now almost sounds like a
+prophecy.</p>
+
+<p>During this period, an interest which had never diminished
+in Great Britain had led to the introduction of experimental
+steamboats in that country. <span class="smcap">Patrick Miller</span>, of
+Dalswinton, had commenced experimenting, in 1786-&#8217;87,
+with boats having double or triple hulls, and propelled by
+paddle-wheels placed between the parts of the compound
+vessel. James Taylor, a young man who had been engaged
+as tutor for Mr. Miller&#8217;s sons, suggested, in 1787, the substitution
+of steam for the manual power which had been,
+up to that time, relied upon in their propulsion. Mr. Miller,
+in 1787, printed a description of his plan of propelling
+apparatus, and in it stated that he had &#8220;reason to believe<span class='pagenum'><a name="Page_242" id="Page_242">[242]</a></span>
+that the power of the Steam-Engine may be applied to work
+the wheels.&#8221;</p>
+
+<div class="figcenter"><a name="Fig72" id="Fig72"></a>
+<img src="images/illo269.png" alt="Miller, Taylor and Symmington" width="400" height="309" />
+<p class="caption"><span class="smcap">Fig. 72.</span>&mdash;Miller, Taylor, and Symmington, 1788.</p></div>
+
+<p>In the winter of 1787-&#8217;88, William Symmington, who
+had planned a new form of steam-engine, and made a successful
+working-model, was employed by Mr. Miller to construct
+an engine for a new boat. This was built; the little engine,
+having two cylinders of but four inches in diameter, was
+placed on board, and a trial was made October 14, 1788.
+The vessel (<a href="#Fig72">Fig. 72</a>) was 25 feet long, of 7 feet beam, and
+made 5 miles an hour.</p>
+
+<p>In the year 1789, a large vessel was built, with an engine
+having a steam-cylinder 18 inches in diameter, and this vessel
+was ready for trial in November of that year. On the
+first trial, the paddle-wheels proved too slight, and broke
+down; they were replaced by stronger wheels, and, in December,
+the boat, on trial, made seven miles an hour.</p>
+
+<p>Miller, like many other inventors, seems to have lost his
+interest in the matter as soon as success seemed assured,
+and dropped it to take up other incomplete plans. More
+than a quarter of a century later, the British Government
+gave Taylor a pension of &pound;50 per annum, and, in 1837, his<span class='pagenum'><a name="Page_243" id="Page_243">[243]</a></span>
+four daughters were each given a similar annuity. Mr.
+Miller received no reward, although he is said to have expended
+over &pound;30,000. The engine of Symmington was
+condemned by Miller as &#8220;the most improper of all steam-engines
+for giving motion to a vessel.&#8221; Nothing more was
+done in Great Britain until early in the succeeding century.</p>
+
+<p>In the United States, several mechanics were now at
+work besides Fitch. Samuel Morey and Nathan Read were
+among these. Nicholas Roosevelt was another. It had
+just been found that American mechanics were able to do
+the required shop-work. The first experimental steam-engine
+built in America is stated to have been made in 1773
+by Christopher Colles, a lecturer before the American Philosophical
+Society at Philadelphia. The first steam-cylinder
+of any considerable size is said<a name="FNanchor_68_68" id="FNanchor_68_68"></a><a
+href="#Footnote_68_68" class="fnanchor">[68]</a> to have been made by
+Sharpe &amp; Curtenius, of New York City.</p>
+
+<p><span class="smcap">Samuel Morey</span> was the son of one of the first settlers
+of Orford, N. H. He was naturally fond of science and
+mechanics, and became something of an inventor. He began
+experimenting with the steamboat in 1790 or earlier,
+building a small vessel, and fitting it with paddle-wheels
+driven by a steam-engine of his own design, and constructed
+by himself.<a name="FNanchor_69_69" id="FNanchor_69_69"></a><a
+href="#Footnote_69_69" class="fnanchor">[69]</a> He made a trial-trip one Sunday morning in
+the summer of 1790, a friend to accompany him, from Oxford,
+up the Connecticut River, to Fairlee, Vt., a distance
+of several miles, and returned safely. He then went to
+New York, and spent the summer of each year until 1793
+in experimenting with his boat and modifications of his
+engine. In 1793 he made a trip to Hartford, returning to
+New York the next summer. His boat was a &#8220;stern-wheeler,&#8221;
+and is stated to have been capable of steaming
+five miles an hour. He next went to Bordentown, N. J.,
+where he built a larger boat, which is said to have been a<span class='pagenum'><a name="Page_244" id="Page_244">[244]</a></span>
+side-wheel boat, and to have worked satisfactorily. His
+funds finally gave out, and he gave up his project after
+having, in 1797, made a trip to Philadelphia. Fulton,
+Livingston, and Stevens met Morey at New York, inspected
+his boat, and made an excursion to Greenwich with him.<a name="FNanchor_70_70" id="FNanchor_70_70"></a><a
+href="#Footnote_70_70" class="fnanchor">[70]</a>
+Livingston is said<a name="FNanchor_71_71" id="FNanchor_71_71"></a><a href="#Footnote_71_71" class="fnanchor">[71]</a>
+to have offered to assist Morey if he
+should succeed in attaining a speed of eight miles an hour.</p>
+
+<p>Morey&#8217;s experiments seem to have been conducted very
+quietly, however, and almost nothing is known of them.
+The author has not been able to learn any particulars of
+the engines used by him, and nothing definite is known of
+the dimensions of either boat or machinery. Morey never,
+like Fitch and Rumsey, sought publicity for his plans or
+notoriety for himself.</p>
+
+<p><span class="smcap">Nathan Read</span>, who has already been <a href="#Read">mentioned</a>, a native
+of Warren, Mass., where he was born in the year 1759,
+and a graduate of Harvard College, was a student of medicine,
+and subsequently a manufacturer of chain-cables and
+other iron-work for ships. He invented, and in 1798 patented,
+a nail-making machine. He was at one time (1800-1803)
+a Member of Congress, and, later, a Justice of the
+Court of Common Pleas, and Chief Justice in Hancock
+County, Me., after his removal to that State in 1807. He
+died in Belfast, Me., in 1849, at the age of ninety years.</p>
+
+<div class="figleft"><a name="Fig73" id="Fig73"></a>
+<img src="images/illo272a.png" alt="Read's Boiler Section" width="170" height="400" />
+<p class="caption"><span class="smcap">Fig. 73.</span>&mdash;Read&#8217;s Boiler in<br />Section, 1788.</p></div>
+
+<div class="figright"><a name="Fig74" id="Fig74"></a>
+<img src="images/illo272b.png" alt="Read's Multi-Tubular Boiler" width="167" height="400" />
+<p class="caption"><span class="smcap">Fig. 74.</span>&mdash;Read&#8217;s Multi-Tubular<br />Boiler, 1788.</p></div>
+
+<p>In the year 1788 he became interested in the problem
+of steam-navigation, and learned something of the work of
+Fitch. He first attempted to design a boiler that should be
+strong, light, and compact, as well as safe. His first plan
+was that of the &#8220;Portable Furnace-Boiler,&#8221; as he called it;
+it was patented August 26, 1791. As designed, it consisted,
+as seen in <a href="#Fig73">Figs. 73</a> and <a href="#Fig74">74</a>, which are reduced from his
+patent drawings, of a shell of cylindrical form, like the
+now common vertical tubular boiler. <i>A</i> is the furnace-door,
+<i>B</i> a heater and feed-water reservoir, <i>D</i> a pipe leading<span class='pagenum'><a name="Page_245" id="Page_245">[245]</a></span>
+the feed-water into the boiler,<a name="FNanchor_72_72" id="FNanchor_72_72"></a><a href="#Footnote_72_72"
+class="fnanchor">[72]</a> <i>E</i> the smoke-pipe, and <i>F</i>
+the steam-pipe leading to the engine. <i>G</i> is the &#8220;shell&#8221; of
+the boiler, and <i>H</i> the fire-box. The crown-sheet, <i>I I</i>, has
+depending from it, in the furnace, a set of water-tubes, <i>b b</i>,
+closed at their lower ends, and another set, <i>a a</i>, which connect
+the water-space above the furnace with the water-bottom,
+<i>K K</i>. <i>L</i> is the furnace, and <i>M</i> the draught-space
+between the boiler and the ash-pit, in which the grates
+are set.</p>
+
+<p>This boiler was intended to be used in both steamboats
+and steam-carriages. The first drawings were made in
+1788 or 1789, as were those of a peculiar form of steam-engine
+which also resembled very closely that afterward
+constructed in Great Britain by Trevithick.<a name="FNanchor_73_73" id="FNanchor_73_73"></a><a href="#Footnote_73_73"
+class="fnanchor">[73]</a> He built a<span class='pagenum'><a name="Page_246" id="Page_246">[246]</a></span>
+boat in 1789, which he fitted with paddle-wheels and a
+crank, which was turned by hand, and, by trial, satisfied
+himself that the system would work satisfactorily.</p>
+
+<p>He then applied for his patent, and spent the greater
+part of the winter of 1789-&#8217;90 in New York, where Congress
+then met, endeavoring to secure it. In January, 1791,
+Read withdrew his petitions for patents, proposing to incorporate
+accounts of new devices, and renewed them a few
+months later. His patents were finally issued, dated August
+26, 1791. John Fitch, James Rumsey, and John Stevens,
+also, all received patents at the same date, for various
+methods of applying steam to the propulsion of vessels.</p>
+
+<p>Read appears to have never succeeded in even experimentally
+making his plans successful. He deserves credit
+for his early and intelligent perception of the importance
+of the subject, and for the ingenuity of his devices. As
+the inventor of the vertical multi-tubular fire-box boiler, he
+has also entitled himself to great distinction. This boiler
+is now in very general use, and is a standard form.</p>
+
+<p>In 1792, Elijah Ormsbee, a Rhode Island mechanic,
+assisted pecuniarily by David Wilkinson, built a small
+steamboat at Winsor&#8217;s Cove, Narragansett Bay, and made
+a successful trial-trip on the Seekonk River. Ormsbee
+used an &#8220;atmospheric engine&#8221; and &#8220;duck&#8217;s-foot&#8221; paddles.
+His boat attained a speed of from three to four miles an
+hour.</p>
+
+<p>In Great Britain, Lord Dundas and William Symmington,
+the former as the purveyor of funds and the latter as
+engineer, followed by Henry Bell, were the first to make
+the introduction of the steam-engine for the propulsion of
+ships so completely successful that no interruption subsequently
+took place in the growth of the new system of
+water-transportation.</p>
+
+<p>Thomas, Lord Dundas, of Kerse, had taken great interest
+in the experiments of Miller, and had hoped to be able
+to apply the new motor on the Forth and Clyde Canal, in<span class='pagenum'><a name="Page_247" id="Page_247">[247]</a></span>
+which he held a large interest. After the failure of the
+earlier experiments, he did not forget the matter; but subsequently,
+meeting with Symmington, who had been Miller&#8217;s
+constructing engineer, he engaged him to continue
+the experiments, and furnished all required capital, about
+&pound;7,000. This was ten years after Miller had abandoned
+his scheme.</p>
+
+<p>Symmington commenced work in 1801. The first boat
+built for Lord Dundas, which has been claimed to have
+been the &#8220;first practical steamboat,&#8221; was finished ready for
+trial early in 1802. The vessel was called the &#8220;Charlotte
+Dundas,&#8221; in honor of a daughter of Lord Dundas, who became
+Lady Milton.</p>
+
+<p>The vessel (<a href="#Fig75">Fig. 75</a>) was driven by a Watt double-acting
+engine, turning a crank on the paddle-wheel shaft.
+The sectional sketch below exhibits the arrangement of the
+machinery. <i>A</i> is the steam-cylinder, driving, by means of
+the connecting-rod, <i>B C</i>, a stern-wheel, <i>E E</i>. <i>F</i> is the
+boiler, and <i>G</i> the tall smoke-pipe. An air-pump and condenser,
+<i>H</i>, is seen under the steam-cylinder.</p>
+
+<div class="figcenter"><a name="Fig75" id="Fig75"></a>
+<img src="images/illo274.png" alt="The 'Charlotte Dundas'" width="400" height="205" />
+<p class="caption"><span class="smcap">Fig. 75.</span>&mdash;The &#8220;Charlotte Dundas,&#8221; 1801.</p></div>
+
+<p>In March, 1802, the boat was brought to Lock No. 20
+on the Forth and Clyde Canal, and two vessels of 70 tons
+burden each taken in tow. Lord Dundas, William Symmington,
+and a party of invited guests, were taken on board,<span class='pagenum'><a name="Page_248" id="Page_248">[248]</a></span>
+and the boat steamed down to Port Glasgow, a distance of
+about 20 miles, against a strong head-wind, in six hours.</p>
+
+<p>The proprietors of the canal were now urged to adopt
+the new plan of towing; but, fearing injury to the banks
+of the canal, they declined to do so. Lord Dundas then
+laid the matter before the Duke of Bridgewater, who gave
+Symmington an order for eight boats like the Charlotte
+Dundas, to be used on his canal. The death of the Duke,
+however, prevented the contract from being carried into
+effect, and Symmington again gave up the project in despair.
+A quarter of a century later, Symmington received
+from the British Government &pound;100, and, a little later, &pound;50
+additional, as an acknowledgment of his services. The
+Charlotte Dundas was laid up, and we hear nothing more
+of that vessel.</p>
+
+<div class="figcenter"><a name="Fig76" id="Fig76"></a>
+<img src="images/illo275.png" alt="The 'Comet'" width="400" height="279" />
+<p class="caption"><span class="smcap">Fig. 76.</span>&mdash;The &#8220;Comet,&#8221; 1812.</p></div>
+
+<p>Among those who saw the Charlotte Dundas, and who
+appreciated the importance of the success achieved by Symmington,
+was <span class="smcap">Henry Bell</span>, who, 10 years afterward, constructed
+the Comet (<a href="#Fig76">Fig. 76</a>), the first passenger-vessel
+built<span class='pagenum'><a name="Page_249" id="Page_249">[249]</a></span>
+in Europe. This vessel was built in 1811, and completed
+January 18, 1812. The craft was of 30 tons burden, 40 feet
+in length, and 10<span class="enum">1</span>&#8725;<span class="denom">2</span> feet breadth of beam. There were <i>two</i>
+paddle-wheels on each side, driven by engines rated at
+three horse-power.</p>
+
+<p>Bell had, it is said, been an enthusiastic believer in the
+advantages to be secured by this application of steam, from
+about 1786. In 1800, and again in 1803, he applied to the
+British Admiralty for aid in securing those advantages by
+experimentally determining the proper form and proportions
+of machinery and vessel; but was not able to convince
+the Admiralty of &#8220;the practicability and great utility
+of applying steam to the propelling of vessels against
+winds and tides, and every obstruction on rivers and seas
+where there was depth of water.&#8221; He also wrote to the
+United States Government, urging his views in a similar
+strain.</p>
+
+<p>Bell&#8217;s boat was, when finished, advertised as a passenger-boat,
+to leave Greenock, where the vessel was built, on
+Mondays, Wednesdays, and Fridays, for Glasgow, 24 miles
+distant, returning Tuesdays, Thursdays, and Saturdays.
+The fare was made &#8220;four shillings for the best cabin, and
+three shillings for the second.&#8221; It was some months before
+the vessel became considered a trustworthy means of conveyance.
+Bell, on the whole, was at first a heavy loser by
+his venture, although his boat proved itself a safe, stanch
+vessel.</p>
+
+<p>Bell constructed several other boats in 1815, and with
+his success steam-navigation in Great Britain was fairly
+inaugurated. In 1814 there were five steamers, all Scotch,
+regularly working in British waters; in 1820 there were
+34, one-half of which were in England, 14 in Scotland, and
+the remainder in Ireland. Twenty years later, at the close
+of the period to which this chapter is especially devoted,
+there were about 1,325 steam-vessels in that kingdom, of
+which 1,000 were English and 250 Scotch.</p>
+
+<p><span class='pagenum'><a name="Page_250" id="Page_250">[250]</a></span>But we must return to America, to witness the first and
+most complete success, commercially, in the introduction of
+the steamboat.</p>
+
+<p>The Messrs. Stevens, Livingston, Fulton, and Roosevelt
+were there the most successful pioneers. The latter is said
+to have built the &#8220;Polacca,&#8221; a small steamboat launched on
+the Passaic River in 1798. The vessel was 60 feet long,
+and had an engine of 20 inches diameter of cylinder and
+2 feet stroke, which drove the boat 8 miles an hour, carrying
+a party of invited guests, which included the Spanish
+Minister. Livingston and John Stevens had induced Roosevelt
+to try their plans still earlier,<a name="FNanchor_74_74" id="FNanchor_74_74"></a><a
+href="#Footnote_74_74" class="fnanchor">[74]</a> paying the expense of
+the experiments. The former adopted the plan of Bernouilli
+and Rumsey, using a centrifugal pump to force a jet of
+water from the stern; the latter used the screw. Livingston
+going to France as United States Minister, Barlow
+carried over the plans of the &#8220;Polacca,&#8221; and Roosevelt&#8217;s
+friends state that a boat built by them, in conjunction with
+Fulton, was a &#8220;sister-ship&#8221; to that vessel. In 1798, Roosevelt
+patented a double engine, having cranks set at right
+angles. As late as 1814 he received a patent for a steam-vessel,
+fitted with paddle-wheels having adjustable floats.
+His boat of 1798 is stated by some writers to have been
+made by him on joint account of himself, Livingston, and
+Stevens. Roosevelt, some years later, was again at work,
+associating himself with Fulton in the introduction of
+steam-navigation of the rivers of the West.<a name="FNanchor_75_75" id="FNanchor_75_75"></a><a
+href="#Footnote_75_75" class="fnanchor">[75]</a></p>
+
+<p>In 1798, the Legislature of New York passed a law giving
+Chancellor Livingston the exclusive right to steam-navigation
+in the waters of the State for a period of 20
+years, <i>provided</i> that he should succeed, within a twelve-month,
+in producing a boat that should steam four miles
+an hour.</p>
+
+<p><span class='pagenum'><a name="Page_251" id="Page_251">[251]</a></span>Livingston did not succeed in complying with the terms
+of the act, but, in 1803, he procured the re&euml;nactment of the
+law in favor of himself and Robert Fulton, who was then
+experimenting in France, after having, in England, watched
+the progress of steam-navigation there, and then taken a
+patent in this country.</p>
+
+<div class="figcenter"><a name="Port10" id="Port10"></a>
+<img src="images/illo278.png" alt="Fulton" width="350" height="427" />
+<p class="caption">Robert Fulton.</p></div>
+
+<p><span class="smcap"><a href="#Port10">Robert Fulton</a></span> was a native of Little Britain, Lancaster
+County, Pa., born 1765. He commenced experimenting
+with paddle-wheels when a mere boy, in 1779, visiting an
+aunt living on the bank of the Conestoga.<a name="FNanchor_76_76" id="FNanchor_76_76"></a><a
+href="#Footnote_76_76" class="fnanchor">[76]</a> During his
+youth he spent much of his time in the workshops of his
+neighborhood, and learned the trade of a watchmaker; but
+he adopted, finally, the profession of an artist, and exhibited
+great skill in portrait-painting. While his tastes were<span class='pagenum'><a name="Page_252" id="Page_252">[252]</a></span>
+at this time taking a decided bent, he is said to have visited
+frequently the house of William Henry, already mentioned,
+to see the paintings of Benjamin West, who in his youth
+had been a kind of prot&eacute;g&eacute; of Mr. Henry; and he may
+probably have seen there the model steamboats which Mr.
+Henry exhibited, in 1783 or 1784, to the German traveler
+Sch&ouml;pff. In later years, Thomas Paine, the author of
+&#8220;<a href="http://www.gutenberg.org/ebooks/3755">Common Sense</a>,&#8221; at one time lived with Mr. Henry, and
+afterward, in 1788, proposed that Congress take up the
+subject for the benefit of the country.</p>
+
+<p>Fulton went to England when he came of age, and
+studied painting with Benjamin West. He afterward
+spent two years in Devonshire, where he met the Duke of
+Bridgewater, who afterward so promptly took advantage
+of the success of the &#8220;Charlotte Dundas.&#8221;</p>
+
+<p>While in England and in France&mdash;where he went in
+1797, and resided some time&mdash;he may have seen something
+of the attempts which were beginning to be made to introduce
+steam-navigation in both of those countries.</p>
+
+<p>At about this time&mdash;perhaps in 1793&mdash;Fulton gave up
+painting as a profession, and became a civil engineer. In
+1797 he went to Paris, and commenced experimenting with
+submarine torpedoes and torpedo-boats. In 1801 he had
+succeeded so well with them as to create much anxiety in
+the minds of the English, then at war with France.</p>
+
+<p>He had, as early as 1793, proposed plans for steam-vessels,
+both to the United States and the British Governments,
+and seems never entirely to have lost sight of the
+subject.<a name="FNanchor_77_77" id="FNanchor_77_77"></a><a href="#Footnote_77_77" class="fnanchor">[77]</a>
+While in France he lived with Joel Barlow, who
+subsequently became known as a poet, and as Embassador
+to France from the United States, but who was then engaged
+in business in Paris.</p>
+
+<p>When about leaving the country, Fulton met Robert
+Livingston (Chancellor Livingston, as he is often called),<span class='pagenum'><a name="Page_253" id="Page_253">[253]</a></span>
+who was then (1801) Embassador of the United States at
+the court of France. Together they discussed the project
+of applying steam to navigation, and determined to attempt
+the construction of a steamboat on the Seine; and in the
+early spring of the year 1802, Fulton having attended Mrs.
+Barlow to Plombi&egrave;res, where she had been sent by her physician,
+he there made drawings and models, which were
+sent or described to Livingston. In the following winter
+Fulton completed a model side-wheel boat.</p>
+
+<div class="figcenter"><a name="Fig77" id="Fig77"></a>
+<img src="images/illo280.png" alt="Fulton's Experiments" width="442" height="350" />
+<p class="caption"><span class="smcap">Fig. 77.</span>&mdash;Fulton&#8217;s Experiments.</p></div>
+
+<p>January 24, 1803, he delivered this model to MM.
+Molar, Bordel, and Montgolfier, with a descriptive memoir,
+in which he stated that he had, by experiment, proven that
+side-wheels were better than the &#8220;chaplet&#8221; (paddle-floats
+set on an endless chain).<a name="FNanchor_78_78" id="FNanchor_78_78"></a><a
+href="#Footnote_78_78" class="fnanchor">[78]</a> These gentlemen were then
+building for Fulton and Livingston their first boat, on
+L&#8217;Isle des Cygnes, in the Seine. In planning this boat, Fulton<span class='pagenum'><a name="Page_254" id="Page_254">[254]</a></span>
+had devised many different methods of applying steam
+to its propulsion, and had made some experiments to determine
+the resistance of fluids. He therefore had been
+able to calculate, more accurately than had any earlier inventor,
+the relative size and proportions of boat and machinery.</p>
+
+<div class="figcenter"><a name="Fig78" id="Fig78"></a>
+<img src="images/illo281.png" alt="Fulton's Table of Resistances" width="724" height="350" />
+<p class="caption"><span class="smcap">Fig. 78.</span>&mdash;Fulton&#8217;s Table of Resistances.</p></div>
+
+<p>The author has examined a large collection of Fulton&#8217;s
+drawings, among which are sketches, very neatly executed,
+of many of these plans, including the chaplet, side-wheel,
+and stern-wheel boats, driven by various forms of steam-engine,
+some working direct, and some geared to the paddle-wheel
+shaft. <a href="#Fig77">Figs. 77</a> and <a href="#Fig78">78</a> are engraved from
+two of these sheets. The first represents the method
+adopted by Fulton to determine the resistance of masses of
+wood of various forms and proportions, when towed through
+water. The other is &#8220;A Table of the resistance of bodies
+moved through water, taken from experiments made in
+England by a society for improving Naval architecture, between
+the years 1793 and 1798&#8221; (<a href="#Fig78">Fig. 78</a>). This latter is
+from a certified copy of &#8220;The Original Drawing on file in
+the Office of the Clerk of the New York District, making
+a part of the Demonstration of the patent granted to Robert
+Fulton, Esqr., on the 11th day of February, 1809. Dated<span class='pagenum'><a name="Page_255" id="Page_255">[255]</a></span>
+this 3rd March, 1814,&#8221; and is signed by Theron Rudd, Clerk
+of the New York District. Resistances are given in pounds
+per square foot.</p>
+
+<p>Guided by these experiments and calculations, therefore,
+Fulton directed the construction of his vessel. It was completed
+in the spring of 1803. But, unfortunately, the hull
+of the little vessel was too weak for its heavy machinery,
+and it broke in two and sank to the bottom of the Seine.
+Undiscouraged, Fulton at once set about repairing damages.
+He was compelled to direct the rebuilding of the
+hull. The machinery was little injured. In June, 1803,
+the reconstruction was completed, and the vessel was set
+afloat in July. The hull was 66 feet long, of 8 feet beam,
+and of light draught.</p>
+
+<p>August 9, 1803, this boat was cast loose, and steamed
+up the Seine, in presence of an immense concourse of spectators.
+A committee of the National Academy, consisting
+of Bougainville, Bossuet, Carnot, and P&eacute;rier, were present
+to witness the experiment. The boat moved but slowly,
+making only between 3 and 4 miles an hour against the
+current, the speed through the water being about 4<span class="enum">1</span>&#8725;<span class="denom">2</span> miles;
+but this was, all things considered, a great success.</p>
+
+<div class="figcenter"><a name="Fig79" id="Fig79"></a>
+<img src="images/illo283.png" alt="Barlow's Water-Tube Boiler" width="400" height="228" />
+<p class="caption"><span class="smcap">Fig. 79.</span>&mdash;Barlow&#8217;s Water-Tube Boiler, 1793.</p></div>
+
+<p>The experiment was successful, but it attracted little
+attention, notwithstanding the fact that its success had
+been witnessed by the committee of the Academy and by
+many well-known savants and mechanics, and by officers on
+Napoleon&#8217;s staff. The boat remained a long time on the
+Seine, near the palace. The water-tube boiler of this vessel
+(<a href="#Fig79">Fig. 79</a>) is still preserved at the Conservatoire des Arts et
+M&eacute;tiers at Paris, where it is known as Barlow&#8217;s boiler. Barlow
+patented it in France as early as 1793, as a steamboat-boiler,
+and states that the object of his construction was to
+obtain the greatest possible extent of heating-surface.</p>
+
+<p>Fulton endeavored to secure the pecuniary aid and the
+countenance of the First Consul, but in vain.</p>
+
+<p>Livingston wrote home, describing the trial of this steamboat<span class='pagenum'><a name="Page_256" id="Page_256">[256]</a></span>
+and its results, and procured the passage of an act by
+the Legislature of the State of New York, extending a
+monopoly granted him in 1798 for the term of 20 years
+from April 5, 1803, the date of the new law, and extending
+the time allowed for proving the practicability of driving
+a boat four miles an hour by steam to two years from the
+same date. A later act further extended the time to April,
+1807.</p>
+
+<p>In May, 1804, Fulton went to England, giving up all
+hope of success in France with either his steamboats or his
+torpedoes. Fulton had already written to Boulton &amp; Watt,
+ordering an engine to be built from plans which he furnished
+them; but he had not informed them of the purpose
+to which it was to be applied. This engine was to have a
+steam-cylinder 2 feet in diameter and of 4 feet stroke. The
+engine of the Charlotte Dundas was of very nearly the
+same size; and this fact, and the visit of Fulton to Symmington
+in 1801, as described by the latter, have been made
+the basis of a claim that Fulton was a copyist of the plans
+of others. The general accordance of the dimensions of
+his boat on the Seine with those of the &#8220;Polacca&#8221; of Roosevelt
+is also made the basis of similar claims by the friends<span class='pagenum'><a name="Page_257" id="Page_257">[257]</a></span>
+of the latter. It would appear, however, that Symmington&#8217;s
+statement is incorrect, as Fulton was in France, experimenting
+with torpedoes, at the time (July, 1801<a name="FNanchor_79_79"
+id="FNanchor_79_79"></a><a href="#Footnote_79_79" class="fnanchor">[79]</a>) when
+he is accused of having obtained from the English engineer
+the dimensions and a statement of the performance of his
+vessel. Yet a fireman employed by Symmington has made
+an affidavit to the same statement. It is evident, however,
+from what has preceded, that those inventors and builders
+who were at that time working with the object of introducing
+the steamboat were usually well acquainted with what
+had been done by others, and with what was being done
+by their contemporaries; and it is undoubtedly the fact
+that each profited, so far as he was able, by the experience
+of others.</p>
+
+<p>While in England, however, Fulton was certainly not
+so entirely absorbed in the torpedo experiments with which
+he was occupied in the years 1804-&#8217;6 as to forget his plans
+for a steamboat; and he saw the engine ordered by him in
+1804 completed in the latter year, and preceded it to New
+York, sailing from Falmouth in October, 1806, and reaching
+the United States December 13, 1806.</p>
+
+<p>The engine was soon received, and Fulton immediately
+contracted for a hull in which to set it up. Meantime, Livingston
+had also returned to the United States, and the two
+enthusiasts worked together on a larger steamer than any
+which had yet been constructed.</p>
+
+<div class="figcenter"><a name="Fig80" id="Fig80"></a>
+<img src="images/illo285a.png" alt="The Clermont" width="400" height="254" />
+<p class="caption"><span class="smcap">Fig. 80.</span>&mdash;The Clermont, 1807.</p></div>
+
+<p>In the spring of 1807, the &#8220;Clermont&#8221; (<a href="#Fig80">Fig. 80</a>), as the
+new boat was christened, was launched from the ship-yard of
+Charles Brown, on the East River, New York. In August
+the machinery was on board and in successful operation.
+The hull of this boat was 133 feet long, 18 wide, and 9
+deep. The boat soon made a trip to Albany, running the
+distance of 150 miles in 32 hours running time, and returning
+in 30 hours. The sails were not used on either occasion.<span class='pagenum'><a name="Page_258" id="Page_258">[258]</a></span></p>
+
+<p>This was the first voyage of considerable length ever
+made by a steam-vessel; and Fulton, though not to be
+classed with James Watt as an inventor, is entitled to the
+great honor of having been the first to make steam-navigation
+an every-day commercial success, and of having thus
+made the first application of the steam-engine to ship-propulsion,
+which was not followed by the retirement of the
+experimenter from the field of his labors before success
+was permanently insured.</p>
+
+<div class="figcenter"><a name="Fig81" id="Fig81"></a>
+<img src="images/illo285b.png" alt="Engine of the Clermont" width="600" height="264" />
+<p class="caption"><span class="smcap">Fig. 81.</span>&mdash;Engine of the Clermont, 1808.</p></div>
+
+<p>The engine of the Clermont (<a href="#Fig81">Fig. 81</a>)
+was of rather peculiar<span class='pagenum'><a name="Page_259" id="Page_259">[259]</a></span>
+form, the piston, <i>E</i>, being coupled to the crank-shaft,
+<i>O</i>, by a bell-crank, <i>I H P</i>, and a connecting-rod, <i>P Q</i>, the
+paddle-wheel shaft, <i>M N</i>, being separate from the crank-shaft,
+and connected with the latter by gearing, <i>O O</i>. The
+cylinders were 24 inches in diameter by 4 feet stroke. The
+paddle-wheels had buckets 4 feet long, with a dip of 2 feet.
+Old drawings, made by Fulton&#8217;s own hand, and showing
+the engine as it was in 1808, and the engine of a later
+steamer, the Chancellor Livingston, are in the lecture-room
+of the author at the Stevens Institute of Technology.</p>
+
+<p>The voyage of the Clermont to Albany was attended
+by some ludicrous incidents, which found their counterparts
+wherever, subsequently, steamers were for the first time
+introduced. Mr. Colden, the biographer of Fulton, says
+that she was described, by persons who had seen her passing
+by night, &#8220;as a monster moving on the waters, defying
+wind and tide, and breathing flames and smoke.&#8221;</p>
+
+<p>This first steamboat used dry pine wood for fuel, and
+the flames rose to a considerable distance above the smoke-pipe.
+When the fires were disturbed, mingled smoke and
+sparks would rise high in the air. &#8220;This uncommon light,&#8221;
+says Colden, &#8220;first attracted the attention of the crews of
+other vessels. Notwithstanding the wind and tide were
+averse to its approach, they saw with astonishment that it
+was rapidly coming toward them; and when it came so
+near that the noise of the machinery and paddles was
+heard, the crews (if what was said in the newspapers of the
+time be true), in some instances, shrank beneath their decks
+from the terrific sight, and left their vessels to go on shore;
+while others prostrated themselves, and besought Providence
+to protect them from the approach of the horrible
+monster which was marching on the tides, and lighting its
+path by the fires which it vomited.&#8221;</p>
+
+<p>In the Clermont, Fulton used several of the now characteristic
+features of the American river steamboat, and
+subsequently introduced others. His most important and<span class='pagenum'><a name="Page_260" id="Page_260">[260]</a></span>
+creditable work, aside from that of the introduction of the
+steamboat into every-day use, was the experimental determination
+of the magnitude and the laws of ship-resistance,
+and the systematic proportioning of vessel and machinery
+to the work to be done by them.</p>
+
+<p>The success of the Clermont on the trial-trip was such
+that Fulton soon after advertised the vessel as a regular
+passenger-boat between New York and Albany.<a name="FNanchor_80_80"
+id="FNanchor_80_80"></a><a href="#Footnote_80_80" class="fnanchor">[80]</a></p>
+
+<p>During the next winter the Clermont was repaired and
+enlarged, and in the summer of 1808 was again on the
+route to Albany; and, meantime, two new steamboats&mdash;the
+Raritan and the Car of Neptune&mdash;had been built by Fulton.
+In the year 1811 he built the Paragon. Both of the<span class='pagenum'><a name="Page_261" id="Page_261">[261]</a></span>
+two vessels last named were of nearly double the size of the
+Clermont. A steam ferry-boat was built to ply between
+New York and Jersey City in 1812, and the next year two
+others, to connect the metropolis with Brooklyn. These
+were &#8220;twin-boats,&#8221; the two parallel hulls being connected
+by a &#8220;bridge&#8221; or deck common to both. The Jersey ferry
+was crossed in fifteen minutes, the distance being a mile
+and a half. To-day, the time occupied at the same ferry
+is about ten minutes. Fulton&#8217;s ferry-boat carried, at one
+load, 8 carriages, and about 30 horses, and still had room
+for 300 or 400 foot-passengers. Fulton also designed steam-vessels
+for use on the Western rivers, and, in 1815, some of
+his boats were started as &#8220;packets&#8221; on the line between
+New York and Providence, R. I.</p>
+
+<p>Meantime, the War of 1812 was in progress, and Fulton
+designed a steam vessel-of-war, which was then considered
+a wonderfully formidable craft. His plans were submitted
+to a commission of experienced naval officers, among whom
+were Commodores Decatur and Perry, Captain John Paul
+Jones, Captain Evans, and others whose names are still familiar,
+and were favorably commended. Fulton proposed
+to build a steam-vessel capable of carrying a heavy battery,
+and of steaming four miles an hour. The ship was to be
+fitted with furnaces for red-hot shot. Some of her guns
+were to be discharged below the water-line. The estimated
+cost was $320,000.</p>
+
+<div class="figcenter"><a name="Fig82" id="Fig82"></a>
+<img src="images/illo289.png" alt="Launch of the Fulton 1st" width="600" height="301" />
+<p class="caption"><span class="smcap">Fig. 82.</span>&mdash;Launch of the &#8220;Fulton the First,&#8221; 1804.</p></div>
+
+<p>The construction of the vessel was authorized by Congress
+in March, 1814; the keel was laid June 20, 1814, and
+the vessel was <a href="#Fig82">launched</a> October 29th of the same year.</p>
+
+<p>The &#8220;Fulton the First,&#8221; as she was called, was considered
+an enormous vessel at that time. The hull was double, 156
+feet long, 56 feet wide, and 20 feet deep, measuring 2,475
+tons. In the following May the ship was ready for her
+engine, and in July was so far completed as to steam, on
+a trial-trip, to the ocean at Sandy Hook and back&mdash;53 miles&mdash;in
+8 hours and 20 minutes. In September of the same<span class='pagenum'><a name="Page_262" id="Page_262">[262]</a></span>
+year, with armament and stores on board, the same route
+was traversed again, the vessel making 5<span class="enum">1</span>&#8725;<span class="denom">2</span> miles an hour.
+The vessel, as thus completed, had a double hull, each
+about 20 feet longer than the Clermont, and separated by a
+space 15 feet across. Her engine, having a steam-cylinder
+48 inches in diameter and of 5 feet stroke of piston, was
+furnished with steam by a copper boiler 22 feet long, 12
+feet wide, and 8 feet high, and turned a wheel between the
+two hulls which was 16 feet in diameter, and carried
+&#8220;floats&#8221; or &#8220;buckets&#8221; 14 feet long, and with a dip of 4
+feet. The engine was in one of the two hulls, and the
+boiler in the other. The sides, at the gun-deck, were 4 feet
+10 inches thick, and her spar-deck was surrounded by heavy
+musket-proof bulwarks. The armament consisted of 30
+32-pounders, which were intended to discharge red-hot
+shot. There was one heavy mast for each hull, fitted with
+large latteen sails. Each end of each hull was fitted with
+a rudder. Large pumps were carried, which were intended
+to throw heavy streams of water upon the decks of the enemy,
+with a view to disabling the foe by wetting his ordnance
+and ammunition. A submarine gun was to have
+been carried at each bow, to discharge shot weighing 100
+pounds, at a depth of 10 feet below the water-line.</p>
+
+<p><span class='pagenum'><a name="Page_263" id="Page_263">[263]</a></span>This was the first application of the steam-engine to
+naval purposes, and, for the time, it was an exceedingly
+creditable one. Fulton, however, did not live to see the
+ship completed. He was engaged in a contest with Livingston,
+who was then endeavoring to obtain permission
+from the State of New Jersey to operate a line of steamboats
+in the waters of the Hudson River and New York
+Bay, and, while returning from attending a session of the
+Legislature at Trenton, in January, 1815, was exposed to
+the weather on the bay at a time when he was ill prepared
+to withstand it. He was taken ill, and died February 24th of
+that year. His death was mourned as a national calamity.</p>
+
+<p>From the above brief sketch of this distinguished man
+and his work, it is seen that, although Robert Fulton is not
+entitled to distinction as an inventor, he was one of the
+ablest, most persistent, and most successful of those who
+have done so much for the world by the introduction of the
+inventions of others. He was an intelligent engineer and
+an enterprising business-man, whose skill, acuteness, and
+energy have given the world the fruits of the inventive
+genius of all who preceded him, and have thus justly
+earned for him a fame that can never be lost.</p>
+
+<p>Fulton had some active and enterprising rivals.</p>
+
+<p>Oliver Evans had, in 1801 or 1802, sent one of his engines,
+of about 150 horse-power, to New Orleans, for the
+purpose of using it to propel a vessel owned by Messrs.
+McKeever and Valcourt, which was there awaiting it. The
+engine was actually set up in the boat, but at a low stage
+of the river, and no trial could be made until the river
+should again rise, some months later. Having no funds to
+carry them through so long a period, Evans&#8217;s agents were
+induced to remove the engine again, and to set it up in a
+saw-mill, where it created great astonishment by its extraordinary
+performance in sawing lumber.</p>
+
+<p>Livingston and Roosevelt were also engaged in experiments
+quite as early as Fulton, and perhaps earlier.</p>
+
+<p><span class='pagenum'><a name="Page_264" id="Page_264">[264]</a></span>The prize gained by Fulton was, however, most closely
+contested by Colonel <span class="smcap">John Stevens</span>, of Hoboken, who has
+been <a href="#Stevens">already mentioned</a> in connection with the early history
+of railroads, and who had been since 1791 engaged in
+similar experiments. In 1789 he had petitioned the Legislature
+of the State of New York for a grant similar to that
+accorded to Livingston, and he then stated that his plans
+were complete, and on paper.</p>
+
+<div class="figcenter"><a name="Fig83" id="Fig83"></a>
+<img src="images/illo291.png" alt="Section of Steam-Boiler" width="350" height="220" />
+<p class="caption"><span class="smcap">Fig. 83.</span>&mdash;Section of Steam-Boiler, 1804.</p></div>
+
+<p>In 1804, while Fulton was in Europe, Stevens had completed
+a steamboat, 68 feet long and of 14 feet beam, which
+combined novelties and merits of design in a manner that
+exhibited the best possible evidence of remarkable inventive
+talent, as well as of the most perfect appreciation of the
+nature of the problem which he had proposed to himself to
+solve. Its boiler (<a href="#Fig83">Fig. 83</a>) was of what is now known as the
+water-tubular variety. It was quite similar to some now
+known as sectional boilers, and contained 100 tubes 2 inches
+in diameter and 18 inches long, each fastened at one end to
+a central water-leg and steam-drum, and plugged at the
+other end. The flames from the furnace passed around and
+among the tubes, the water being inside them. The engine
+(<a href="#Fig84">Fig. 84</a>) was a <i>direct-acting high-pressure</i> condensing engine,
+having a 10-inch cylinder, 2 feet stroke of piston, and
+drove a <i>screw</i> having four blades, and of a form which, even
+to-day, appears quite good. The whole is a most remarkable
+piece of early engineering.</p>
+
+<div class="figcenter"><a name="Fig84" id="Fig84"></a>
+<img src="images/illo292a.png" alt="Stevens's Engine, Boiler, Screw-Propeller" width="500" height="281" />
+<p class="caption"><span class="smcap">Fig. 84.</span>&mdash;Engine, Boiler, and Screw-Propellers used by Stevens, 1804.</p></div>
+
+<p><span class='pagenum'><a name="Page_265" id="Page_265">[265]</a></span>A model of this little steamer, built in 1804, is preserved
+in the lecture-room of the Department of Mechanical Engineering
+at the Stevens Institute of Technology; and the
+machinery itself, consisting of the high-pressure &#8220;sectional&#8221;
+or &#8220;safety&#8221; tubular boiler, as it would be called to-day, the
+high-pressure condensing engine, with rotating valves, and
+twin screw-propellers, as just described, is given a place of
+honor in the model-room, or museum, where it contrasts
+singularly with the mechanism contributed to the collection
+by manufacturers and inventors of our own time. The hub
+and blade of a single screw, also used with the same machinery,
+is likewise to be seen there.</p>
+
+<div class="figcenter"><a name="Fig85" id="Fig85"></a>
+<img src="images/illo292b.png" alt="Stevens's Screw Steamer" width="500" height="350" />
+<p class="caption"><span class="smcap">Fig. 85.</span>&mdash;Stevens&#8217;s Screw Steamer, 1804.</p></div>
+
+<p><span class='pagenum'><a name="Page_266" id="Page_266">[266]</a></span>Stevens seems to have been the first to fully recognize
+the importance of the principle involved in the construction
+of the sectional steam-boiler. His eldest son, John Cox
+Stevens, was in Great Britain in the year 1805, and, while
+there, patented another modification of this type of boiler.
+In his specification, he details both the method of construction
+and the principles which determine its form. He says
+that he describes this invention as it was made known to
+him by his father, and adds:</p>
+
+<p>&#8220;From a series of experiments made in France, in 1790,
+by M. Belamour, under the auspices of the Royal Academy
+of Sciences, it has been found that, within a certain range
+the elasticity of steam is nearly doubled by every addition
+of temperature equal to 30&deg; of Fahrenheit&#8217;s thermometer.
+These experiments were carried no higher than 280&deg;, at
+which temperature the elasticity of steam was found equal
+to about four times the pressure of the atmosphere. By
+experiments which have lately been made by myself, the
+elasticity of steam at the temperature of boiling oil, which
+has been estimated at about 600&deg;, was found to equal 40
+times the pressure of the atmosphere.</p>
+
+<p>&#8220;To the discovery of this principle or law, which obtains
+when water assumes a state of vapor, I certainly
+can lay no claim; but to the application of it, upon certain
+principles, to the improvement of the steam-engine, I do
+claim exclusive right.</p>
+
+<p>&#8220;It is obvious that, to derive advantage from an application
+of this principle, it is absolutely necessary that
+the vessel or vessels for generating steam should have
+strength sufficient to withstand the great pressure from an
+increase of elasticity in the steam; but this pressure is increased
+or diminished in proportion to the capacity of the
+containing vessel. The principle, then, of this invention
+consists in forming a boiler by means of a system, or combination
+of a number of small vessels, instead of using, as
+in the usual mode, one large one; the relative strength of<span class='pagenum'><a name="Page_267" id="Page_267">[267]</a></span>
+the materials of which these vessels are composed increasing
+in proportion to the diminution of capacity. It will
+readily occur that there are an infinite variety of possible
+modes of effecting such combinations; but, from the nature
+of the case, there are certain limits beyond which it becomes
+impracticable to carry on improvement. In the boiler I am
+about to describe, I apprehend that the improvement is carried
+to the utmost extent of which the principle is capable.
+Suppose a plate of brass of one foot square, in which a
+number of holes are perforated; into each of which holes is
+fixed one end of a copper tube, of about an inch in diameter
+and two feet long; and the other ends of these tubes
+inserted in like manner into a similar piece of brass; the
+tubes, to insure their tightness, to be cast in the plates;
+these plates are to be inclosed at each end of the pipes by
+a strong cap of cast-iron or brass, so as to leave a space of
+an inch or two between the plates or ends of the pipes and
+the cast-iron cap at each end; the caps at each end are to
+be fastened by screw-bolts passing through them into the
+plates; the necessary supply of water is to be injected by
+means of a forcing-pump into the cap at one end, and
+through a tube inserted into the cap at the other end the
+steam is to be conveyed to the cylinder of the steam-engine;
+the whole is then to be encircled in brickwork or masonry
+in the usual manner, placed either horizontally or perpendicularly,
+at option.</p>
+
+<p>&#8220;I conceive that the boiler above described embraces
+the most eligible mode of applying the principle before
+mentioned, and that it is unnecessary to give descriptions
+of the variations in form and construction that may be
+adopted, especially as these forms may be diversified in
+many different modes.&#8221;</p>
+
+<p>Boilers of the character of those described in the specification
+given above were used on the locomotive built by
+John Stevens in 1824-&#8217;25, and one of them remains in the
+collections of the Stevens Institute of Technology.</p>
+
+<p><span class='pagenum'><a name="Page_268" id="Page_268">[268]</a></span>The use of such a boiler 70 years ago is even more remarkable
+than the adoption of the screw-propeller, in such
+excellent proportions, 30 years before the labors of Smith
+and of Ericsson brought the screw into general use; and
+we have, in this strikingly original combination, as good
+evidence of the existence of unusual engineering talent in
+this great engineer as we found of his political and statesmanlike
+ability in his efforts to forward the introduction of
+railways.</p>
+
+<p>Colonel John Stevens designed a peculiar form of iron-clad
+in the year 1812, which has been since reproduced by
+no less distinguished and successful an engineer than the
+late John Elder, of Glasgow, Scotland. It consisted of a
+saucer-shaped hull, carrying a heavy battery, and plated
+with iron of ample thickness to resist the shot fired from
+the heaviest ordnance then known. This vessel was secured
+to a swivel, and was anchored in the channel to be defended.
+A set of screw-propellers, driven by steam-engines, and situated
+beneath the vessel, where they were safe against
+injury by shot, were so arranged as to permit the vessel to
+be rapidly revolved about its centre. As each gun was
+brought into line of fire, it was discharged, and was then
+reloaded before coming around again. This was probably
+the earliest embodiment of the now well-established &#8220;Monitor&#8221;
+principle. It was probably the first iron-clad ever
+designed. It has recently been again brought out and introduced
+into the Russian navy, and is there called the
+&#8220;Popoffka.&#8221;</p>
+
+<p>The first of Stevens&#8217;s boats performed so well, that he
+immediately built another one, using the same engine as
+before, but employing a larger boiler, and propelling the
+vessel by <i>twin screws</i>, the latter being another instance of
+his use of a device brought forward long afterward as new,
+and frequently adopted. This boat was sufficiently successful
+to prove the practicability of making steam-navigation a
+commercial success; and Stevens, assisted by his sons, built<span class='pagenum'><a name="Page_269" id="Page_269">[269]</a></span>
+a boat which he named the &#8220;Ph&oelig;nix,&#8221; and made the first
+trial in 1807, but just too late to anticipate Fulton. This
+boat was driven by paddle-wheels.</p>
+
+<div class="figcenter"><a name="Fig86" id="Fig86"></a>
+<img src="images/illo296.png" alt="Stevens's Twin-Screw Steamer" width="500" height="278" />
+<p class="caption"><span class="smcap">Fig. 86.</span>&mdash;Stevens&#8217;s Twin-Screw Steamer, 1805.</p></div>
+
+<p>The Ph&oelig;nix, being shut out of the waters of the State
+of New York by the monopoly held by Fulton and Livingston,
+was used for a time between New York and New
+Brunswick, and then, anticipating a better pecuniary return,
+it was concluded to send her to Philadelphia, to ply on the
+Delaware.</p>
+
+<p>At that time no canal offered the opportunity to make
+an inland passage; and in June, 1808, Robert L. Stevens,
+a son of John, started with her to make the passage by sea.
+Although meeting a gale of wind, he arrived at Philadelphia
+safely, having been the first to trust himself on the
+open sea in a vessel relying entirely upon steam-power.</p>
+
+<p>From this time forward the Stevenses, father and sons,
+continued to construct steam-vessels; and, after the breaking
+down of the Fulton monopoly by the courts, they built
+the most successful steamboats that ran on the Hudson
+River.</p>
+
+<p>After Fulton and Stevens had thus led the way, steam-navigation
+was introduced very rapidly on both sides of the
+ocean; and on the Mississippi the number of boats set afloat
+was soon large enough to fulfill Evans&#8217;s prediction that the<span class='pagenum'><a name="Page_270" id="Page_270">[270]</a></span>
+navigation of that river would ultimately be effected by
+steam-vessels.</p>
+
+<div class="figcenter"><a name="Port11" id="Port11"></a>
+<img src="images/illo297.png" alt="R. L. Stevens" width="350" height="444" />
+<p class="caption">Robert L. Stevens.</p></div>
+
+<p>The changes and improvements which, during the 20
+years succeeding the time of Fulton and of John Stevens,
+gradually led to the adoption of the now recognized type
+of &#8220;American river-boat&#8221; and its steam-engine, were principally
+made by that son of the senior Stevens, who has
+already been mentioned&mdash;<span class="smcap"><a href="#Port11">Robert L. Stevens</a></span>&mdash;and who
+became known later as the designer and builder of the first
+well-planned iron-clad ever constructed, the Stevens Battery.
+Much of his best work was done during his father&#8217;s
+lifetime.</p>
+
+<p>He made many extended and most valuable, as well
+as interesting, experiments on ship-propulsion, expending
+much time and large sums of money upon them; and many
+years before they became generally understood, he had arrived<span class='pagenum'><a name="Page_271" id="Page_271">[271]</a></span>
+at a knowledge not only of the laws governing the
+variation of resistance at excessive speeds, but he had determined,
+and had introduced into his practice, those forms
+of least resistance and those graceful water-lines which have
+only recently distinguished the practice of other successful
+naval architects.</p>
+
+<p>Referring to his invaluable services, President King,
+who seems to have been the first to thoroughly appreciate
+the immense amount of original invention and the surprising
+excellence of the engineering of this family, in a lecture
+delivered in New York in 1851, gave, for the first time, a
+connected and probably accurate description of their work,
+upon which nearly all later accounts have been based.</p>
+
+<p>Young Stevens began working in his father&#8217;s machine-shop
+in 1804 or 1805, when a mere boy, and thus acquired
+at a very early age that familiarity with practical details of
+work and of business which is essential to perfect success.
+It was he who introduced the now common &#8220;hollow water-line&#8221;
+in the Ph&oelig;nix, and thus anticipated the claims of the
+builders of the once famous &#8220;Baltimore clippers,&#8221; and of
+the inventors of the &#8220;wave-line&#8221; form of vessels. In the
+same vessel he adopted a feathering paddle-wheel and the
+guard-beam now universally seen in our river steamboats.</p>
+
+<div class="figcenter"><a name="Fig87" id="Fig87"></a>
+<img src="images/illo299.png" alt="Feathering Paddle-Wheel" width="408" height="400" />
+<p class="caption"><span class="smcap">Fig. 87.</span>&mdash;The Feathering Paddle-Wheel.</p></div>
+
+<p>As usually constructed, this arrangement of float is as
+shown in <a href="#Fig87">Fig. 87</a>. The rods, <i>F F</i>, connect the eccentrically-set
+collar, <i>G</i>, carried on <i>H</i>, a pin mounted on the paddle-beam
+outside the wheel, or an eccentric secured to the
+vessel, with the short arms, <i>D D</i>, by which the paddles are
+turned upon the pins, <i>E E</i>. <i>A</i> is the centre of the paddle-wheel,
+and <i>C C</i> are arms. Circular hoops, or bands, connect
+all of the arms, each of which carries a float. They
+are all thus tied together, forming a very firm and powerful
+combination to resist external forces.</p>
+
+<p>The steamboat Philadelphia was built in the year 1813,
+and the young naval architect took advantage of the opportunity
+to introduce several new devices, including screw-bolts<span class='pagenum'><a name="Page_272" id="Page_272">[272]</a></span>
+in place of tree-nails, and diagonal knees of wood and
+of iron. Two years later he altered the engines of this boat,
+and arranged them to work steam expansively. A little
+later he commenced using anthracite coal, which had been
+discovered in 1791 by Philip Ginter, and introduced at
+Wilkesbarre, Pa., in the smith-shops, some years before the
+Revolution. It had been used in a peculiar grate devised by
+Judge Fell, of that town, in 1808. Oliver Evans also had
+used it in stoves even earlier than the latter date, and at
+about the same time it had been used in the blast-furnace<a name="FNanchor_81_81"
+id="FNanchor_81_81"></a><a href="#Footnote_81_81" class="fnanchor">[81]</a>
+at Kingston. Stevens was the first of whom we have record
+who was thoroughly successful in using, as a steam-coal,
+the new and almost unmanageable fuel. He fitted up the<span class='pagenum'><a name="Page_273" id="Page_273">[273]</a></span>
+boiler of the steamboat Passaic for it in 1818, and adopted
+anthracite as a steaming-coal. He used it in a cupola-furnace
+in the same year, and its use then rapidly became general
+in the Eastern States.</p>
+
+<p>Stevens continued his work of improving the beam-engine
+for many years. He designed the now universally-used
+&#8220;skeleton-beam,&#8221; which is one of the characteristic features
+of the American engine, and placed the first example of this
+light and elegant, yet strong, construction on the steamer
+Hoboken in the year 1822. He built the Trenton, which was
+then considered an extraordinarily powerful, fast, and handsome
+vessel, two years afterward, and placed the two boilers
+on the guards&mdash;a custom which is still general on the river
+steamboats of the Eastern States. In this vessel he also
+adopted the plan of making the paddle-wheel floats in two
+parts, placing one above the other, and securing the upper
+half on the forward and the lower half on the after side of
+the arm, thus obtaining a smoother action of the wheel,
+and less loss by oblique pressures.</p>
+
+<div class="figcenter"><a name="Fig88" id="Fig88"></a>
+<img src="images/illo301.png" alt="The North America and The Albany" width="585" height="269" />
+<p class="caption"><span class="smcap">Fig. 88.</span>&mdash;The North America and Albany, 1827-&#8217;30.</p></div>
+
+<p>In 1827 he built the North America (<a href="#Fig88">Fig. 88</a>), one of
+his largest and most successful steamers, a vessel fitted with
+a pair of engines each 44<span class="enum">1</span>&#8725;<span class="denom">2</span> inches in diameter of cylinder
+and 8 feet stroke of piston, making 24 revolutions per minute,
+driving the boat 15 to 16 miles an hour. Anticipating
+difficulty in keeping the long, light, shallow vessel in shape
+when irregularly laden, and when steaming at the high
+speed expected to be obtained when her powerful engine
+was exerting its maximum effort, he adopted the expedient
+of stiffening the hull by means of a truss of simple form.
+This proved thoroughly satisfactory, and the &#8220;hog-frame,&#8221;
+as it has since been inelegantly but universally called, is
+still one of the peculiar features of every American river-steamer
+of any considerable size. It was in the North
+America, also, that he first introduced the artificial blast
+for forcing the fires, which is still another detail of now
+usual practice.<span class='pagenum'><a name="Page_274" id="Page_274">[274]</a></span></p>
+
+<p>Stevens next turned his attention to the engine again,
+and adopted spring bearings under the paddle-shaft of the<span class='pagenum'><a name="Page_275" id="Page_275">[275]</a></span>
+New Philadelphia in 1828, and fitted the steam-cylinder
+with the &#8220;double-poppet&#8221; valve, which is now universally
+used on beam-engines. This consists of two disk-valves,
+connected by the valve-spindle. The disks are of unequal
+sizes, the smaller passing through the seat of the larger.
+When seated, the pressure of the steam is, in the steam-valve,
+taken on the upper side of the larger and the lower
+side of the smaller disk, thus producing a partial balancing
+of the valve, and rendering it easy to work the heaviest engine
+by the hand-gear. The two valve-seats are formed in
+the top and the bottom, respectively, of the steam-passage
+leading to the cylinder; and when the valve is raised, the
+steam enters at the top and the bottom at the same time,
+and the two currents, uniting, flow together into the steam-cylinder.
+The same form of valve is used as an exhaust-valve.</p>
+
+<div class="figcenter"><a name="Fig89" id="Fig89"></a>
+<img src="images/illo302.png" alt="Stevens's Return Tubular Boiler" width="391" height="350" />
+<p class="caption"><span class="smcap">Fig. 89.</span>&mdash;Stevens&#8217;s Return Tubular Boiler, 1832.</p></div>
+
+<p>At about the same time he built the now standard form
+of return tubular boilers for moderate pressures. In the
+<a href="#Fig89">figure</a>, <i>S</i> is the steam and <i>W</i> the water space, and <i>F</i> the
+furnace. The direction of the currents of smoke and gas
+are shown by the arrows.</p>
+
+<p>Some years later (1840), Stevens commenced using
+steam-packed pistons on the Trenton, in which steam was<span class='pagenum'><a name="Page_276" id="Page_276">[276]</a></span>
+admitted by self-adjusting valves behind the metallic packing-rings,
+setting them out more effectively than did the
+steel springs then (and still) usually employed.</p>
+
+<p>His pistons, thus fitted, worked well for many years. A
+set of the small brass check-valves used in a piston of this
+kind, built by Stevens, and preserved in the cabinets of the
+Stevens Institute of Technology, are good evidence of the
+ingenuity and excellent workmanship which distinguished
+the machinery constructed under the direction of this great
+engineer.</p>
+
+<div class="figleft"><a name="Fig90" id="Fig90"></a>
+<img src="images/illo303.png" alt="Stevens's Valve-Motion" width="300" height="271" />
+<p class="caption"><span class="smcap">Fig. 90.</span>&mdash;Stevens&#8217;s Valve-Motion.</p></div>
+
+<p>The now familiar &#8220;Stevens cut-off,&#8221; a peculiar device
+for securing the expansion of steam in the steam-cylinder,
+was the invention (1841) of Robert L. Stevens and a nephew,
+who inherited the same constructive talent which distinguished
+the first of these great men&mdash;Mr. Francis B. Stevens.
+In this form of valve-gear, the steam and exhaust
+valves are independently worked by separate eccentrics, the
+latter being set in the usual manner, opening and closing
+the exhaust-passages just before the crank passes its centre.
+The steam-eccentric is so placed that the steam-valve is
+opened as usual, but closed when but about one-half the
+stroke has been made. This result is accomplished by giving
+the eccentric a greater throw than
+is required by the motion of the valve,
+and permitting it to move through a
+portion of its path without moving the
+valve. Thus, in <a href="#Fig90">Fig. 90</a>, if <i>A B</i> be the
+direction of motion of the eccentric-rod,
+the valve would ordinarily open
+the steam-port when the eccentric assumes
+the position <i>O C</i>, closing when
+the eccentric has passed around to <i>O D</i>. With the Stevens
+valve-gear, the valve is opened when the eccentric reaches
+<i>O E</i>, and closes when it arrives at <i>O F</i>. The steam-valve
+of the opposite end of the cylinder is open while the eccentric
+is moving from <i>O M</i> to <i>O K</i>. Between <i>K</i> and <i>E</i>,
+and<span class='pagenum'><a name="Page_277" id="Page_277">[277]</a></span>
+between <i>F</i> and <i>M</i>, both valves are seated. <i>H B</i> is proportional
+to the lift of the valve, and <i>O H</i> to the motion of
+the valve-gear when out of contact with the valve-lifters.
+While the crank is moving through an arc, <i>E F</i>, steam is
+entering the cylinder; from <i>F</i> to <i>M</i> the steam is expanding.
+At <i>M</i> the stroke is completed, and the other steam-valve
+opens. The ratio <span class="enum">E M</span>&#8725;<span class="denom">E L</span> is the ratio of expansion.</p>
+
+<p>This form of cut-off motion is still a very usual one,
+and can be seen in nearly all steamers in the United States
+not using the device of Sickles. It was at about this time,
+also, that Stevens, having succeeded his father in the business
+of introducing the steam-engine in land-transportation,
+as well as on the water, adopted the use of steam expansively
+on the locomotives of the Camden &amp; Amboy Railroad,
+which was controlled and built by capital furnished principally
+by the Messrs. Stevens. He at the same time constructed
+eight-wheeled engines for heavy work, and adopted
+anthracite coal as fuel. In the latter change he was thoroughly
+successful, and the same improvement was made
+with engines built for fast traffic in 1848.</p>
+
+<p>The most remarkable of all the applications of steam-power
+proposed by Robert L. Stevens was that known as
+the Stevens Steam Iron-Clad Battery. As has already been
+stated, Colonel John Stevens had proposed, as early as 1812,
+to build a circular or saucer-shaped iron-clad, like those
+built 60 years later for the Russian Navy. Nothing was
+done, however, although the son revived the idea in a modified
+form 20 years afterward. In the years 1813-&#8217;14, the
+war with England being then in progress, he invented,
+after numerous and hazardous experiments, an <i>elongated
+shell</i>, to be fired from ordinary smooth-bored cannon. Having
+perfected this invention, he sold the secret to the
+United States, after making experiments to prove their destructiveness
+so decisive as to leave no doubt of the efficacy
+of such projectiles.</p>
+
+<p><span class='pagenum'><a name="Page_278" id="Page_278">[278]</a></span>As early as 1837 he had perfected a plan of an iron-clad
+war-vessel, and in August, 1841, his brothers, James C. and
+Edwin A. Stevens, representing Robert L., addressed a
+letter to the Secretary of the Navy, proposing to build an
+iron-clad vessel of high speed, with all its machinery below
+the water-line, and having submerged screw-propellers.
+The armament was to consist of the most powerful rifled
+guns, loading at the breech, and provided with elongated
+shot and shell. In the year 1842, having contracted to build
+for the United States Government a large war-steamer on
+this plan, which should be shot and shell proof, Robert L.
+Stevens built a steamboat at Bordentown, for the sole purpose
+of experimenting on the forms and curves of propeller-blades,
+as compared with side-wheels, and continued his experiments
+for many months. After some delay, during
+which Mr. Stevens and his brothers were engaged with their
+experiments and in perfecting their plans, the keel of an
+iron-clad was laid down in a dry-dock which had been constructed
+for the purpose at great cost. This vessel was to
+have been 250 feet long, of 40 feet beam, and 28 feet deep.
+The machinery was designed to furnish 700 indicated horse-power.
+The plating was proposed to be 4<span class="enum">1</span>&#8725;<span class="denom">2</span> inches thick&mdash;the
+same thickness of armor as was adopted 10 years later
+by the French for their comparatively rude constructions.</p>
+
+<p>In 1854, such marked progress had been made in the
+construction of ordnance that Mr. Stevens was no longer
+willing to proceed with the original plans, fearing that,
+were the ship completed, it might prove not invulnerable,
+and might throw some discredit upon its designer, as well
+as upon the navy of which it was to form a part. The
+work, which had, in those years of peace, progressed very
+slowly and intermittently, was therefore stopped entirely,
+the vessel given up, and in 1854 the keel of a ship of vastly
+greater size and power was laid down. The new design
+was 415 feet long, of 45 feet beam, and of something over
+5,000 tons displacement. The thickness of armor proposed<span class='pagenum'><a name="Page_279" id="Page_279">[279]</a></span>
+was 6<span class="enum">3</span>&#8725;<span class="denom">4</span>
+inches&mdash;2<span class="enum">1</span>&#8725;<span class="denom">4</span> inches thicker than that of the first
+French and British iron-clads&mdash;and the machinery was designed
+by Mr. Stevens to be of 8,624 indicated horse-power,
+driving twin-screws, and propelling the vessel 20 miles or
+more an hour. As with the preceding design, the progress
+of construction was intermittent and very slow. Government
+advanced funds, and then refused to continue the
+work; successive administrations alternately encouraged
+and discouraged the engineer; and he finally, cutting loose
+entirely from all official connections, went on with the work
+at his own expense.</p>
+
+<p>The remarkable genius of the elder Stevens was well
+reflected in the character of his son, and is in no way better
+exemplified than by the accuracy with which, in this great
+ship, those forms and proportions, both of hull and machinery,
+were adopted which are now, twenty-five years later,
+recognized as most correct under similar conditions. The
+lines of the vessel are beautifully fair and fine, and are what
+J. Scott Russell has called &#8220;wave-lines,&#8221; or trochoidal lines,
+such as Rankine has shown to be the best possible for easy
+propulsion. The proportion of length to midship dimensions
+is such as to secure the speed proposed with a minimum
+resistance, and to accord closely with the proportions
+arrived at and adopted by common consent in present
+transoceanic navigation by the best&mdash;not to say radical&mdash;builders.</p>
+
+<p>The death of Robert L. Stevens occurred in April, 1856,
+when this larger vessel had advanced so far toward completion
+that the hull and machinery were practically finished,
+and it only remained to add the armor-plating, and to decide
+upon the form of fighting-house and upon the number
+and size of guns. The construction of the vessel, which had
+proceeded slowly and intermittently during the years of
+peace, as successive administrations had considered it necessary
+to continue the payment of appropriations, or had
+stopped temporarily in the absence of any apparent immediate<span class='pagenum'><a name="Page_280" id="Page_280">[280]</a></span>
+necessity for continuance of the work, was again interrupted
+by his death.</p>
+
+<p>The name of Robert L. Stevens will be long remembered
+as that of one of the greatest of American mechanics, the
+most intelligent of naval architects, and as the first, and
+one of the greatest, of those to whom we are indebted for
+the commencement of the mightiest of revolutions in the
+methods and implements of modern naval warfare. American
+mechanical genius and engineering skill have rarely
+been too promptly recognized, and no excuse will be required
+for an attempt (which it is hoped may yet be made)
+to place such splendid work as that of the Messrs. Stevens
+in a light which shall reveal both its variety and extent and
+its immense importance.</p>
+
+<p>While Fulton was introducing the steamboat upon the
+waters of New York Bay and the Hudson River, and while
+the Stevenses, father and sons, were rapidly bringing out a
+fleet of steamers on the Delaware River and Bay, other
+mechanics were preparing to contest the field with them as
+opportunity offered, and as legislative acts authorizing monopoly
+expired by limitation or were repealed.</p>
+
+<p>About 1821, Robert L. Thurston, John Babcock, and
+Captain Stephen T. Northam, of Newport, R. I., commenced
+building steamboats, beginning with a small craft
+intended for use at Slade&#8217;s Ferry, on an arm of Narragansett
+Bay, near Fall River. They afterward built vessels to
+ply on Long Island Sound. One of their earliest boats was
+the Babcock, built at Newport in 1826. The engine was
+built by Thurston and Babcock, at Portsmouth, R. I.
+They were assisted in their work by Richard Sanford, and
+with funds by Northam. The engine was of 10 or 12
+inches diameter of cylinder, and 3 or 4 feet stroke of piston.
+The boiler was a form of &#8220;pipe-boiler,&#8221; subsequently
+(1824) patented by Babcock. The water used was injected
+into the hot boiler as fast as required to furnish steam, no
+water being retained in the steam-generator. This boat<span class='pagenum'><a name="Page_281" id="Page_281">[281]</a></span>
+was succeeded, in 1827-&#8217;28, by a larger vessel, the Rushlight,
+for which the engine was built by James P. Allaire,
+at New York, while the boat was built at Newport. The
+boilers of both vessels had tubes of cast-iron. The smaller
+of these boats was of 80 tons burden; it steamed from
+Newport to Providence, 30 miles, in 3<span class="enum">1</span>&#8725;<span class="denom">2</span> hours, and to New
+York, a distance of 175 miles, in 25 hours, using 1<span class="enum">3</span>&#8725;<span class="denom">4</span> cord
+of wood.<a name="FNanchor_82_82" id="FNanchor_82_82"></a><a href="#Footnote_82_82" class="fnanchor">[82]</a>
+Thurston and Babcock subsequently removed
+to Providence, where the latter soon died. Thurston continued
+to build steam-engines at this place until nearly a
+half-century later, dying in 1874.<a name="FNanchor_83_83" id="FNanchor_83_83"></a><a
+href="#Footnote_83_83" class="fnanchor">[83]</a> The establishment
+founded by him, after various changes, became the Providence
+Steam-Engine Works.</p>
+
+<p>James P. Allaire, of New York, the West Point Iron
+Foundery, at West Point, on the Hudson River, and Daniel
+Copeland and his son, Charles W. Copeland, on the
+Connecticut River, were also early builders of engines for
+steam-vessels. Daniel Copeland was probably the first
+(1850) to adopt a slide-valve working with a lap to secure
+the expansion of steam. His steamboats were then usually
+stern-wheel vessels, and were built to ply on several routes
+on the Connecticut River and Long Island Sound. The
+son, Charles W. Copeland, went to West Point, and while
+there designed some heavy marine steam-machinery, and
+subsequently designed several steam vessels-of-war for the
+United States Navy. He was the earliest designer of iron
+steamers in the United States, building the Siamese in 1838.
+This steamer was intended for use on Lake Pontchartrain
+and the canal to New Orleans. It had two hulls, was 110
+feet long, and drew but 22 inches of water, loaded. The
+two horizontal non-condensing engines turned a single
+paddle-wheel placed between the two hulls, driving the
+boat 10 miles an hour. The hull was constructed of plates<span class='pagenum'><a name="Page_282" id="Page_282">[282]</a></span>
+of iron 10 feet long, formed on blocks after having been
+heated in a furnace constructed especially for the purpose.
+The frames were of T-iron, which was probably here used
+for the first time. The same engineer, associated with Samuel
+Hart, a well-known naval constructor, built, in 1841, for
+the United States Navy, the iron steamer Michigan, a war-vessel
+intended for service on the great northern lakes.
+This vessel is still in service, and in good order. The hull
+is 162<span class="enum">1</span>&#8725;<span class="denom">2</span> feet in length, 27 feet in breadth,
+and 12<span class="enum">1</span>&#8725;<span class="denom">2</span> feet in
+depth, measuring 500 tons. The frames were made of
+T-iron, stiffened by reverse bars of L-iron. The keel-plate
+was <span class="enum">5</span>&#8725;<span class="denom">8</span> inch thick, the bottom plates
+<span class="enum">3</span>&#8725;<span class="denom">8</span>, and the sides
+<span class="enum">3</span>&#8725;<span class="denom">16</span> inch.
+The deck-beams were of iron, and the vessel, as a whole,
+was a good specimen of iron-ship building.</p>
+
+<p>During the period from 1830 to 1840, a considerable
+number of the now standard details of steam-engine and
+steamboat construction were devised or introduced by Copeland.
+He was probably the first to use (on the Fulton, 1840)
+an independent engine to drive the blowing-fans where an
+artificial draught was required. He made a practice of
+fitting his steamers with a &#8220;bilge-injection,&#8221; by means of
+which the vessel could be freed of water, through the condenser
+and air-pump, when leaking seriously; the condensing-water
+is, in such a case, taken from inside the vessel,
+instead of from the sea. This is probably an American device.
+It was in use in the United States previously to 1835,
+as was the use of anthracite coal on steamers, which was continued
+by Copeland in manufacturing and in air-furnaces, as
+well as on steamboats. He also modified the form of Stevens&#8217;s
+double-poppet valve, giving it such shape that it was comparatively
+easy to grind it tight and to keep it in order.</p>
+
+<p>In 1825, James P. Allaire, of New York, built compound
+engines for the Henry Eckford, and subsequently
+constructed similar engines for several other steamers, one
+of which, the Sun, made the trip from New York to Albany
+in 12 hours 18 minutes. He used steam at 100 pounds<span class='pagenum'><a name="Page_283" id="Page_283">[283]</a></span>
+pressure. Erastus W. Smith afterward introduced this
+form of engine on the Great Lakes, and still later they were
+introduced into British steamers. The machinery of the
+steamer Buckeye State was constructed at the Allaire
+Works, New York, in 1850, from the designs of John
+Baird and Erastus W. Smith, the latter being the designing
+and constructing engineer. The steamer was placed
+on the route between Buffalo, Cleveland, and Detroit, in
+1851, and gave most satisfactory results, consuming less
+than two-thirds the fuel required by a similar vessel of the
+same line fitted with the single-cylinder engine. The steam-cylinders
+of this engine were placed one within the other,
+the low-pressure exterior cylinder being annular. They
+were 37 and 80 inches in diameter respectively, and the
+stroke was 11 feet. Both pistons were connected to one
+cross-head, and the general arrangement of the engine was
+similar to that of the common form of beam-engine. The
+steam-pressure was from 70 to 75 pounds&mdash;about the maximum
+pressure adopted a quarter of a century later on transatlantic
+lines. This steamer was of high speed, as well as
+economical of fuel.</p>
+
+<p>In the year 1830, there were 86 steamers on the Hudson
+River and in Long Island Sound.</p>
+
+<p>During the early part of the nineteenth century, the
+introduction of the steamboat upon the waters of the great
+rivers of the interior of the United States was one of the
+most notable details of its history. Inaugurated by the
+unsuccessful experiment of Evans, the building of steamboats
+on those waters, once commenced, never ceased; and
+a generation after Fitch&#8217;s burial on the shore of the Ohio,
+his last wish&mdash;that he might lie &#8220;where the song of the
+boatman would enliven the stillness of his resting-place, and
+the music of the steam-engine soothe his spirit&#8221;&mdash;was fulfilled
+day by day unceasingly.</p>
+
+<p>Nicholas J. Roosevelt was, as has been already stated,
+the first to take a steamboat down the great rivers. His<span class='pagenum'><a name="Page_284" id="Page_284">[284]</a></span>
+boat was built at Pittsburgh in 1811, under an arrangement
+with Fulton and Livingston, from Fulton&#8217;s plans. It was
+called the &#8220;New Orleans,&#8221; was of about 200 tons burden,
+and was propelled by a stern-wheel, assisted, when the
+winds were favorable, by sails carried on two masts. The
+hull was 138 feet long, 30 feet beam, and the cost of the
+whole, including engines, was about $40,000. The builder,
+with his family, an engineer, a pilot, and six &#8220;deck-hands,&#8221;
+left Pittsburgh in October, 1811, reaching Louisville in 70
+hours (steaming about 10 miles an hour), and New Orleans
+in 14 days, steaming from Natchez.</p>
+
+<p>The next steamers built on Western waters were probably
+the Comet and the Vesuvius, both of which were in
+service some time. The Comet was finally laid aside, and
+the engine used to drive a mill, and the Vesuvius was destroyed
+by the explosion of her boilers. As early as 1813
+there were two shops at Pittsburgh building steam-engines.
+Steamboat-building now became an important and lucrative
+business in the West; and it is stated that as early as 1840
+there were a thousand steamers on the Mississippi and its
+tributaries.</p>
+
+<p>In the Washington, built at Wheeling, Va., in 1816,
+under the direction of Captain Henry M. Shreve, the boilers,
+which had previously been placed in the hold, were
+carried on the main-deck, and a &#8220;hurricane-deck&#8221; was
+built over them. Shreve substituted two horizontal direct-acting
+engines for the single upright engine used by Fulton,
+drove them by high-pressure steam without condensation,
+and attached them, one on each side the boat, to
+cranks placed at right angles. He adopted a cam cut-off
+expanding the steam considerably, and the flue-boiler of
+Evans. At that time the voyage from New Orleans to
+Louisville occupied three weeks, and Shreve was made the
+subject of many witticisms when he predicted that the time
+would ultimately be shortened to ten days. It is now made
+in four days. The Washington was seized at New Orleans,<span class='pagenum'><a name="Page_285" id="Page_285">[285]</a></span>
+in 1817, by order of Livingston, who claimed that his rights
+included the monopoly of the navigation of the Mississippi
+and its tributaries. The courts decided adversely on this
+claim, and the release of the Washington was the act which
+removed every obstacle to the introduction of steam-navigation
+throughout the United States.</p>
+
+<p>The first steamer on the Great Lakes was the Ontario,
+built in 1816, at Sackett&#8217;s Harbor. Fifteen years later,
+Western steamboats had taken the peculiar form which has
+since usually distinguished them.</p>
+
+<p>The use of the steam-engine for ocean-navigation kept
+pace with its introduction on inland waters. Begun by
+Robert L. Stevens in the United States, in the year 1808,
+and by his contemporaries, Bell and Dodd, in Great Britain,
+it steadily and rapidly advanced in effectiveness and importance,
+and has now nearly driven the sailing fleet from the
+ocean. Transatlantic steam-navigation began with the voyage
+of the American steamer Savannah from Savannah, Ga.,
+to St. Petersburg, Russia, <i>via</i> Great Britain and the North-European
+ports, in the year 1819. Fulton, not long before
+his death, planned a vessel, which it was proposed to place
+in service in the Baltic Sea; but circumstances compelled a
+change of plan finally, and the steamer was placed on a
+line between Newport, R. I., and the city of New York;
+and the Savannah, several years later, made the voyage then
+proposed for Fulton&#8217;s ship. The Savannah measured 350
+tons, and was constructed by Crocker &amp; Fickett, at Corlears
+Hook, N. Y. She was purchased by Mr. Scarborough, of
+Savannah, who placed Captain Moses Rogers, previously in
+command of the Clermont and of Stevens&#8217;s boat, the Ph&oelig;nix,
+in charge. The ship was fitted with steam-machinery
+and paddle-wheels, and sailed for Savannah April 27, 1819,
+making the voyage successfully in seven days. From Savannah,
+the vessel sailed for Liverpool May 26th, and arrived
+at that port June 20th. During this trip the engines
+were used 18 days, and the remainder of the voyage was<span class='pagenum'><a name="Page_286" id="Page_286">[286]</a></span>
+made under sail. From Liverpool the Savannah sailed,
+July 23d, for the Baltic, touching at Copenhagen, Stockholm,
+St. Petersburg, and other ports. At St. Petersburg,
+Lord Lyndock, who had been a passenger, was landed; and,
+on taking leave of the commander of the steamer, the distinguished
+guest presented him with a silver tea-kettle, suitably
+inscribed with a legend referring to the importance of
+the event which afforded him the opportunity. The Savannah
+left St. Petersburg in November, passing New York
+December 9th, and reaching Savannah in 50 days from the
+date of departure, stopping four days at Copenhagen, Denmark,
+and an equal length of time at Arundel, Norway.
+Several severe gales were met in the Atlantic, but no serious
+injury was done to the ship.</p>
+
+<p>The Savannah was a full-rigged ship. The wheels
+were turned by an inclined direct-acting low-pressure engine,
+having a steam-cylinder 40 inches in diameter and 6
+feet stroke of piston. The paddle-wheels were of wrought-iron,
+and were so attached that they could be detached and
+hoisted on board when it was desired. After the return of
+the ship to the United States, the machinery was removed
+and was sold to the Allaire Works, of New York. The
+steam-cylinder was exhibited by the purchasers at the
+&#8220;World&#8217;s Fair&#8221; at New York thirty years later. The vessel
+was employed, as a sailing-vessel, on a line between
+New York and Savannah, and was finally lost in the year
+1822. Under sail, with a moderate breeze, this ship is said
+to have sailed about three knots, and to have steamed five
+knots. Pine-wood was used as the fuel, which fact accounts
+for the necessity of making the transatlantic voyage partly
+under sail.</p>
+
+<p>Renwick states that another vessel, ship-rigged and
+fitted with a steam-engine, was built at New York in 1819,
+to ply between New York and Charleston, and to New Orleans
+and Havana, and that it proved perfectly successful
+as a steamer, having good speed, and proving an excellent<span class='pagenum'><a name="Page_287" id="Page_287">[287]</a></span>
+sea-boat. The enterprise was, however, pecuniarily a failure,
+and the vessel was sold to the Brazilian Government
+after the removal of the engine. In 1825 the steamer Enterprise
+made a voyage to India, sailing and steaming as
+the weather and the supply of fuel permitted. The voyage
+occupied 47 days.</p>
+
+<p>Notwithstanding these successful passages across the
+ocean, and the complete success of the steamboat in rivers
+and harbors, it was asserted, as late as 1838, by many who
+were regarded as authority, that the passage of the ocean
+by steamers was quite impracticable, unless possibly they
+could steam from the coasts of Europe to Newfoundland or
+to the Azores, and, replenishing their coal-bunkers, resume
+their voyages to the larger American ports. The voyage
+was, however, actually accomplished by two steamers in
+the year just mentioned. These were the Sirius, a ship of
+700 tons and of 250 horse-power, and the Great Western,
+of 1,340 tons and 450 horse-power. The latter was built
+for this service, and was a large ship for that time, measuring
+236 feet in length. Her wheels were 28 feet in diameter,
+and 10 feet in breadth of face. The Sirius sailed from
+Cork April 4, 1838, and the Great Western from Bristol
+April 8th, both arriving at New York on the same day&mdash;April
+23d&mdash;the Sirius in the morning, and the Great Western
+in the afternoon.</p>
+
+<p>The Great Western carried out of Bristol 660 tons of
+coal. Seven passengers chose to take advantage of the opportunity,
+and made the voyage in one-half the time usually
+occupied by the sailing-packets of that day. Throughout
+the voyage the wind and sea were nearly ahead, and
+the two vessels pursued the same course, under very similar
+conditions. Arriving at New York, they were received
+with the greatest possible enthusiasm. They were saluted
+by the forts and the men-of-war in the harbor; the merchant-vessels
+dipped their flags, and the citizens assembled
+on the Battery, and, coming to meet them in boats of all<span class='pagenum'><a name="Page_288" id="Page_288">[288]</a></span>
+kinds and sizes, cheered heartily. The newspapers of the
+time were filled with the story of the voyage and with descriptions
+of the steamers themselves and of their machinery.</p>
+
+<p>A few days later the two steamers started on their return
+to Great Britain, the Sirius reaching Falmouth safely
+in 18 days, and the Great Western making the voyage to
+Bristol in 15 days, the latter meeting with head-winds and
+working, during a part of the time, against a heavy gale
+and in a high sea, at the rate of but two knots an hour. The
+Sirius was thought too small for this long and boisterous
+route, and was withdrawn and replaced on the line between
+London and Cork, where the ship had previously been employed.
+The Great Western continued several years in
+the transatlantic trade.</p>
+
+<p>Thus these two voyages inaugurated a transoceanic
+steam-service, which has steadily grown in extent and in
+importance. The use of steam-power for this work of extended
+ocean-transportation has never since been interrupted.
+During the succeeding six years the Great Western
+made 70 passages across the Atlantic, occupying on the
+voyages to the westward an average of 15<span class="enum">1</span>&#8725;<span class="denom">2</span> days, and eastward
+13<span class="enum">1</span>&#8725;<span class="denom">2</span>. The quickest passage to New York was made
+in May, 1843, in 12 days and 18 hours, and the fastest
+steaming was logged 12 months earlier, when the voyage
+from New York was made in 12 days and 7 hours.</p>
+
+<p>Meantime, several other steamers were built and placed
+in the transatlantic trade. Among these were the Royal
+William, the British Queen, the President, the Liverpool,
+and the Great Britain. The latter, the finest of the fleet,
+was launched in 1843. This steamer was 300 feet long, 50
+feet beam, and of 1,000 horse-power. The hull was of iron,
+and the whole ship was an example of the very best work
+of that time. After several voyages, this vessel went
+ashore on the coast of Ireland, and there remained several
+weeks, but was finally got off, without having suffered serious
+injury&mdash;a remarkable illustration of the stanchness<span class='pagenum'><a name="Page_289" id="Page_289">[289]</a></span>
+of an iron hull when well built and of good material. The
+vessel was repaired, and many years afterward was still
+afloat, and engaged in the transportation of passengers and
+merchandise to Australia.</p>
+
+<p>The &#8220;Cunard Line&#8221; of transatlantic steamers was established
+in the year 1840. The first of the line&mdash;the Britannia&mdash;sailed
+from Liverpool for New York, July 4th of
+that year, and was followed, on regular sailing-days, by the
+other three of the four ships with which the company commenced
+business. These four vessels had an aggregate tonnage
+of 4,600 tons, and their speed was less than eight
+knots. To-day, the tonnage of a single vessel of the fleet
+exceeds that of the four; the total tonnage has risen to
+many times that above given. There are 50 steamers in
+the line, aggregating nearly 50,000 horse-power. The
+speed of the steamships of the present time is double that
+of the vessels of that date, and passages are not infrequently
+made in eight days.</p>
+
+<p>The form of steam-engine in most general use at this
+time, on transatlantic steamers, was that known as the
+&#8220;side-lever engine.&#8221; It was first given the standard form
+by Messrs. Maudsley &amp; Co., of London, about 1835, and
+was built by them for steamers supplied to the British Government
+for general mail service.</p>
+
+<div class="figcenter"><a name="Fig91" id="Fig91"></a>
+<img src="images/illo317.png" alt="The Atlantic" width="400" height="283" />
+<p class="caption"><span class="smcap">Fig. 91.</span>&mdash;The Atlantic, 1851.</p></div>
+
+<p>The steam-vessels of the time are well represented in
+the accompanying engraving (<a href="#Fig91">Fig. 91</a>) of the steamship
+Atlantic&mdash;a vessel which was shortly afterward (1851) built
+as the pioneer steamer of the American &#8220;Collins Line.&#8221;
+This steamship was one of several which formed the earliest
+of American steamship-lines, and is one of the finest examples
+of the type of paddle-steamers which was finally superseded
+by the later screw-fleets. The &#8220;Collins Line&#8221; existed
+but a very few years, and its failure was probably determined
+as much by the evident and inevitable success of
+screw-propulsion as by the difficulty of securing ample capital,
+complete organization, and efficient general management.<span class='pagenum'><a name="Page_290" id="Page_290">[290]</a></span>
+This steamer was built at New York&mdash;the hull
+by William Brown, and the machinery by the Novelty
+Iron-Works. The length of the hull was 276 feet, its
+breadth 45 feet, and the depth of hold 31<span class="enum">1</span>&#8725;<span class="denom">2</span> feet. The
+width over the paddle-boxes was 75 feet. The ship measured
+2,860 tons. The form of the hull was then peculiar
+in the fineness of its lines; the bow was sharp, and the
+stern fine and smooth, and the general outline such as best
+adapted the ship for high speed. The main saloon was
+about 70 feet long, and the dining-room was 60 feet in
+length and 20 feet wide. The state-rooms were arranged
+on each side the dining &#8220;saloon,&#8221; and accommodated 150
+passengers. These vessels were beautifully fitted up, and
+with them was inaugurated that wonderful system of passenger-transportation
+which has since always been distinguished
+by those comforts and conveniences which the
+American traveler has learned to consider his by right.</p>
+
+<div class="figcenter"><a name="Fig92" id="Fig92"></a>
+<img src="images/illo318.png" alt="Side-Lever Engine" width="400" height="391" />
+<p class="caption"><span class="smcap">Fig. 92.</span>&mdash;The Side-Lever Engine, 1849.</p></div>
+
+<p>The machinery of these ships was, for that time, remarkably
+powerful and efficient. The engines were of the<span class='pagenum'><a name="Page_291" id="Page_291">[291]</a></span>
+side-lever type, as illustrated in <a href="#Fig92">Fig. 92</a>, which represents
+the engine of the Pacific, designed by Mr. Charles W.
+Copeland, and built by the Allaire Works.</p>
+
+<p>In this type of engine, as is seen, the piston-rod was
+attached to a cross-head working vertically, from which, at
+each side, links, <i>B C</i>, connected with the &#8220;side-lever,&#8221;
+<i>D E F</i>. The latter vibrated about a &#8220;main centre&#8221; at <i>E</i>,
+like the overhead beam of the more common form of engine;
+from its other end, a &#8220;connecting-rod,&#8221; <i>H</i>, led to the
+&#8220;cross-tail,&#8221; <i>W</i>, which was, in turn, connected to the crank-pin,
+<i>I</i>. The condenser, <i>M</i>, and air-pump, <i>Q</i>, were constructed
+in the same manner as those of other engines, their
+only peculiarities being such as were incident to their location
+between the cylinder, <i>A</i>, and the crank, <i>I J</i>. The<span class='pagenum'><a name="Page_292" id="Page_292">[292]</a></span>
+paddle-wheels were of the common &#8220;radial&#8221; form, covered
+in by paddle-boxes so strongly built that they were rarely
+injured by the heaviest seas.</p>
+
+<p>These vessels surpassed, for a time, all other sea-going
+steamers in speed and comfort, and made their passages
+with great regularity. The minimum length of voyage
+of the Baltic and Pacific, of this line, was 9 days 19
+hours.</p>
+
+<p>During the latter part of the period the history of which
+has been here given, the marine steam-engine became subject
+to very marked changes in type and in details, and a
+complete revolution was effected in the method of propulsion.
+This change has finally resulted in the universal
+adoption of a new propelling instrument, and in driving the
+whole fleet of paddle-steamers from the ocean. The Great
+Britain was a screw-steamer.</p>
+
+<p>The screw-propeller, which, as has been stated, was
+probably first proposed by Dr. Hooke in 1681, and by Dr.
+Bernouilli, of Groningen, at about the middle of the eighteenth
+century, and by Watt in 1784, was, at the end of the
+century, tried experimentally in the United States by David
+Bushnell, an ingenious American, who was then conducting
+the experiments with torpedoes which were the cause of the
+incident which originated that celebrated song by Francis
+Hopkinson, the &#8220;Battle of the Kegs,&#8221; using the screw to
+propel one of his submarine boats, and by John Fitch, and
+by Dallery in France.</p>
+
+<p>Joseph Bramah, of Great Britain, May 9, 1785, patented
+a screw-propeller identical in general arrangement with
+those used to-day. His sketch exhibits a screw, apparently
+of very fair shape, carried on an horizontal shaft, which
+passes out of the vessel through a stuffing-box, the screw
+being wholly submerged. Bramah does not seem to have
+put his plan in practice. It was patented again in England,
+also, by Littleton in 1794, and by Shorter in 1800.</p>
+
+<p>John Stevens, however, first gave the screw a practically<span class='pagenum'><a name="Page_293" id="Page_293">[293]</a></span>
+useful form, and used it successfully, in 1804 and 1805, on the
+single and the twin screw boats which he built at that time.
+This propelling instrument was also tried by Trevithick,
+who planned a vessel to be propelled by a steam-engine
+driving a screw, at about this time, and his scheme was laid
+before the Navy Board in the year 1812. His plans included
+an iron hull. Francis Pettit Smith tried the screw also in
+the year 1808, and subsequently.</p>
+
+<p>Joseph Ressel, a Bohemian, proposed to use a screw in
+the propulsion of balloons, about 1812, and in the year
+1826 proposed its use for marine propulsion. He is said to
+have built a screw-boat in the year 1829, at Trieste, which
+he named the Civetta. The little craft met with an accident
+on the trial-trip, and nothing more was done.</p>
+
+<p>The screw was finally brought into general use through
+the exertions of John Ericsson, a skillful Swedish engineer,
+who was residing in England in the year 1836, and of Mr.
+F. P. Smith, an English farmer. Ericsson patented a peculiar
+form of screw-propeller, and designed a steamer 40
+feet in length, of 8 feet beam, and drawing 3 feet of water.
+The screw was double, two shafts being placed the one
+within the other, revolving in opposite directions, and carrying
+the one a right-hand and the other a left-hand
+screw. These screws were 5<span class="enum">1</span>&#8725;<span class="denom">4</span> feet in diameter. On her
+trial-trip this little steamer attained a speed of 10 miles an
+hour. Its power as a &#8220;tug&#8221; was found to be very satisfactory;
+it towed a schooner of 140 tons burden at the rate of
+7 miles, and the large American packet-ship Toronto was
+towed on the Thames at a speed of 5 miles an hour.</p>
+
+<p>Ericsson endeavored to interest the British Admiralty
+in his improvements, and succeeded only so far as to induce
+the Lords of the Admiralty to make an excursion with him
+on the river. No interest was awakened in the new system,
+and nothing was done by the naval authorities. A note to
+the inventor from Captain Beaufort&mdash;one of the party&mdash;was
+received shortly afterward, in which it was stated that the<span class='pagenum'><a name="Page_294" id="Page_294">[294]</a></span>
+excursionists had not found the performance of the little
+vessel to equal their hopes and expectations. All the interests
+of the then existing engine-building establishments
+were opposed to the innovation, and the proverbial conservatism
+of naval men and naval administrations aided in
+procuring the rejection of Ericsson&#8217;s plans.</p>
+
+<p>Fortunately for the United States, it happened, at that
+time, that we had in Great Britain both civil and naval representatives
+of greater intelligence, or of greater boldness
+and enterprise. The consul at Liverpool was Mr. Francis
+B. Ogden, of New Jersey, a gentleman who was somewhat
+familiar with the steam-engine and with steam-navigation.
+He had seen Ericsson&#8217;s plans at an earlier period, and had
+at once seen their probable value. He was sufficiently confident
+of success to place capital at the disposal of the inventor.
+The little screw-boat just described was built with
+funds of which he furnished a part, and was named, in his
+honor, the Francis B. Ogden.</p>
+
+<p>Captain Robert F. Stockton, an officer of the United
+States Navy, and also a resident of New Jersey, was in
+London at the time, and made an excursion with Ericsson
+on the Ogden. He was also at once convinced of the value
+of the new method of application of steam-power to ship-propulsion,
+and gave the engineer an order to build two
+iron screw-steamboats for use in the United States. Ericsson
+was induced, by Messrs. Ogden and Stockton, to take up
+his residence in the United States.<a name="FNanchor_84_84" id="FNanchor_84_84"></a><a
+href="#Footnote_84_84" class="fnanchor">[84]</a> The Stockton was sent
+over to the United States in April, 1839, under sail, and
+was sold to the Delaware &amp; Raritan Canal Company. Her
+name was changed, and, as the New Jersey, she remained
+in service many years.</p>
+
+<p>The success of the boat built by Ericsson was so evident
+that, although the naval authorities remained inactive,
+a private company was formed, in 1839, to work the patents<span class='pagenum'><a name="Page_295" id="Page_295">[295]</a></span>
+of F. P. Smith, and this &#8220;Ship-Propeller Company&#8221; built
+an experimental craft called the Archimedes, and its trial-trip
+was made October 14th of the same year. The speed
+attained was 9.64 miles an hour. The result was in every
+respect satisfactory, and the vessel, subsequently, made
+many voyages from port to port, and finally circumnavigated
+the island of Great Britain. The proprietors of
+the ship were not pecuniarily successful in their venture,
+however, and the sale of the vessel left the company a
+heavy loser. The Archimedes was 125 feet long, of 21 feet
+10 inches beam, and 10 feet draught, registering 232 tons.
+The engines were rated at 80 horse-power. Smith&#8217;s earlier
+experiments (1837) were made with a little craft of 6 tons
+burden, driven by an engine having a steam-cylinder 6
+inches in diameter and 15 inches stroke of piston. The
+funds needed were furnished by a London banker&mdash;Mr.
+Wright.</p>
+
+<p>Bennett Woodcroft had also used the screw experimentally
+as early as 1832, on the Irwell, near Manchester, England,
+in a boat of 55 tons burden. Twin-screws were used,
+right and left handed respectively; they were each two feet
+in diameter, and were given an expanding pitch. The boat
+attained a speed of four miles an hour.</p>
+
+<p>Experiments made subsequently (1843) with this form of
+screw, and in competition with the &#8220;true&#8221; screw of Smith,
+brought out very distinctly the superiority of the former,
+and gave some knowledge of the proper proportions for
+maximum efficiency. In later examples of the Woodcroft
+screw, the blades were made detachable and adjustable&mdash;a
+plan which is still a usual one, and which has proved to be,
+in some respects, very convenient.</p>
+
+<p>When Ericsson reached the United States, he was almost
+immediately given an opportunity to build the Princeton&mdash;a
+large screw-steamer&mdash;and at about the same time the
+English and French Governments also had screw-steamers
+built from his plans, or from those of his agent in England,<span class='pagenum'><a name="Page_296" id="Page_296">[296]</a></span>
+the Count de Rosen. In these latter ships&mdash;the Amphion
+and the Pomona&mdash;the first horizontal direct-acting engines
+ever built were used, and they were fitted with double-acting
+air-pumps, having canvas valves and other novel
+features. The great advantages exhibited by these vessels
+over the paddle-steamers of the time did for screw-propulsion
+what Stephenson&#8217;s locomotive&mdash;the Rocket&mdash;did for
+railroad locomotion ten years earlier.</p>
+
+<p>Congress, in 1839, had authorized the construction of
+three war-vessels, and the Secretary of the Navy ordered
+that two be at once built in the succeeding year. Of these,
+one was the Princeton, the screw-steamer of which the machinery
+was designed by Ericsson. The length of this vessel
+was 164 feet, beam 30<span class="enum">1</span>&#8725;<span class="denom">2</span>
+feet, and depth 21<span class="enum">1</span>&#8725;<span class="denom">2</span> feet. The
+ship drew from 16<span class="enum">1</span>&#8725;<span class="denom">2</span> to 18 feet of water, displacing at those
+draughts 950 and 1,050 tons. The hull had a broad, flat
+floor, with sharp entrance and fine run, and the lines were
+considered at that time remarkably fine.</p>
+
+<p>The screw was of gun-bronze, six-bladed, and was 14
+feet in diameter and of 35 feet pitch; i. e., were there no
+slip, the screw working as if in a solid nut, the ship would
+have been driven forward 35 feet at each revolution.</p>
+
+<p>The engines were two in number, and very peculiar in
+form; the cylinder was, in fact, a <i>semi</i>-cylinder, and the
+place of the piston-rod, as usually built, was taken by a vibrating
+shaft, or &#8220;rock-shaft,&#8221; which carried a piston of
+rectangular form, and which vibrated like a door on its
+hinges as the steam was alternately let into and exhausted
+from each side of it. The great rock-shaft carried, at the
+outer end, an arm from which a connecting-rod led to the
+crank, thus forming a &#8220;direct-acting engine.&#8221;</p>
+
+<p>The draught in the boilers was urged by blowers.
+Ericsson had adopted this method of securing an artificial
+draught ten years before, in one of his earlier vessels, the
+Corsair. The Princeton carried a XII-inch wrought-iron
+gun. This gun exploded after a few trials, with terribly<span class='pagenum'><a name="Page_297" id="Page_297">[297]</a></span>
+disastrous results, causing the death of several distinguished
+men, including members of the President&#8217;s cabinet.</p>
+
+<p>The Princeton proved very successful as a screw-steamer,
+attaining a speed of 13 knots, and was then considered
+very remarkably fast. Captain Stockton, who commanded
+the vessel, was most enthusiastic in praise of her.</p>
+
+<p>Immediately there began a revolution in both civil and
+naval ship-building, which progressed with great rapidity.
+The Princeton was the first of the screw-propelled navy
+which has now entirely displaced the older type of steam-vessel.
+The introduction of the screw now took place with
+great rapidity. Six steamers were fitted with Ericsson&#8217;s
+screw in 1841, 9 in 1842, and nearly 30 in the year 1843.</p>
+
+<p>In Great Britain, France, Germany, and other European
+countries, the revolution was also finally effected, and was
+equally complete. Nearly all sea-going vessels built toward
+the close of the period here considered were screw-steamers,
+fitted with direct-acting, quick-working engines. It was,
+however, many years before the experience of engineers in
+the designing and in the construction and management of
+this new machinery enabled them to properly proportion it
+for the various kinds of service to which they were called
+upon to adapt it. Among other modifications of earlier practice
+introduced by Ericsson was the surface-condenser with
+a circulating pump driven by a small independent engine.</p>
+
+<p>The screw was found to possess many advantages over
+the paddle-wheel as an instrument for ship-propulsion.
+The cost of machinery was greatly reduced by its use; the
+expense of maintenance in working order was, however,
+somewhat increased. The latter disadvantage was, nevertheless,
+much more than compensated by an immense increase
+in the economy of ship-propulsion, which marked
+the substitution of the new instrument and its impelling
+machinery.</p>
+
+<p>When a ship is propelled by paddles, the motion of the
+vessel creates, in consequence of the friction of the fluid<span class='pagenum'><a name="Page_298" id="Page_298">[298]</a></span>
+against the sides and bottom, a current of water which
+flows in the direction in which the ship is moving, and
+forms a current following the ship for a time, and finally
+losing all motion by contact with the surrounding mass of
+water. All the power expended in the production of this
+great stream is, in the case of the paddle-steamer, entirely
+lost. In screw-steamers, however, the propelling instrument
+works in this following current, and the tendency of
+its action is to bring the agitated fluid to rest, taking up
+and thus restoring, usefully, a large part of that energy
+which would otherwise have been lost. The screw is also
+completely covered by the water, and acts with comparative
+efficiency in consequence of its submersion. The rotation
+of the screw is comparatively rapid and smooth, also,
+and this permits the use of small, light, fast-running engines.
+The latter condition leads to economy of weight
+and space, and consequently saves not only the cost of
+transportation of the excess of weight of the larger kind of
+engine, but, leaving so much more room for paying cargo,
+the gain is found to be a double one. Still further, the
+quick-running engine is, other things being equal, the most
+economical of steam; and thus some expense is saved not
+only in the purchase of fuel, but in its transportation, and
+some still additional gain is derived from the increased
+amount of paying cargo which the vessel is thus enabled to
+carry. The change here described was thus found to be
+productive of enormous direct gain. Indirectly, also, some
+advantage was derived from the greater convenience of a
+deck clear from machinery and the great paddle-shaft, in
+the better storage of the lading, the greater facility with
+which the masts and sails could be fitted and used; and
+directly, again, in clear sides unencumbered by great paddle-boxes
+which impeded the vessel by catching both sea
+and wind.</p>
+
+<p>The screw was, for some years, generally regarded as
+simply auxiliary in large vessels, assisting the sails. Ultimately<span class='pagenum'><a name="Page_299" id="Page_299">[299]</a></span>
+the screw became the essential feature, and vessels
+were lightly sparred and were given smaller areas of sail,
+the latter becoming the auxiliary power.</p>
+
+<p>In November of the year 1843, the screw-steamer Midas,
+Captain Poor, a small schooner-rigged craft, left New
+York for China, on probably the first voyage of such length
+ever undertaken by a steamer; and in the following January
+the Edith, Captain Lewis, a bark-rigged screw-vessel,
+sailed from the same port for India and China. The Massachusetts,
+Captain Forbes, a screw-steamship of about 800
+tons, sailed for Liverpool September 15, 1845, the first voyage
+of an American transatlantic passenger-steamer since
+the Savannah&#8217;s pioneer adventure a quarter of a century
+before. Two years later, American enterprise had placed
+both screw and paddle steamers on the rivers of China&mdash;principally
+through the exertions of Captain R. B. Forbes&mdash;and
+steam-navigation was fairly established throughout
+the world.</p>
+
+<p>On comparing the screw-steamer of the present time
+with the best examples of steamers propelled by paddle-wheels,
+the superiority of the former is so marked that it
+may cause some surprise that the revolution just described
+should have progressed no more rapidly. The reason of
+this slow progress, however, was probably that the introduction
+of the rapidly-revolving screw, in place of the slow-moving
+paddle-wheel, necessitated a complete revolution in
+the design of their steam-engines; and the unavoidable
+change from the heavy, long-stroked, low-speed engines
+previously in use, to the light engines, with small cylinders
+and high piston-speed, called for by the new system of propulsion,
+was one that necessarily occurred slowly, and was
+accompanied by its share of those engineering blunders and
+accidents that invariably take place during such periods of
+transition. Engineers had first to learn to design such engines
+as should be reliable under the then novel conditions
+of screw-propulsion, and their experience could only be<span class='pagenum'><a name="Page_300" id="Page_300">[300]</a></span>
+gained through the occurrence of many mishaps and costly
+failures. The best proportions of engines and screws, for a
+given ship, were determined only by long experience, although
+great assistance was derived from the extensive series
+of experiments made with the French steamer Pelican.
+It also became necessary to train up a body of engine-drivers
+who should be capable of managing these new engines; for
+they required the exercise of a then unprecedented amount
+of care and skill. Finally, with the accomplishment of
+these two requisites to success must simultaneously occur
+the enlightenment of the public, professional as well as
+non-professional, in regard to their advantages. Thus it
+happens that it is only after a considerable time that the
+screw attained its proper place as an instrument of propulsion,
+and finally drove the paddle-wheel quite out of use,
+except in shoal water.</p>
+
+<p>Now our large screw-steamers are of higher speed than
+any paddle-steamers on the ocean, and develop their power
+at far less cost. This increased economy is due not only to
+the use of a more efficient propelling instrument, and to
+changes already described, but also, in a great degree, to
+the economy which has followed as a consequence of other
+changes in the steam-engine driving it. The earliest days
+of screw-propulsion witnessed the use of steam of from 5
+to 15 pounds pressure, in a geared engine using jet-condensation,
+and giving a horse-power at an expense of perhaps
+7 to 10, or even more, pounds of coal per hour. A little
+later came direct-acting engines with jet-condensation and
+steam at 20 pounds pressure, costing about 5 or 6 pounds
+per horse-power per hour. The steam-pressure rose a little
+higher with the use of greater expansion, and the economy
+of fuel was further improved. The introduction of the surface-condenser,
+which began to be generally adopted some
+ten years ago, brought down the cost of power to from 3
+to 4 pounds in the better class of engines. At about the
+same time, this change to surface-condensation helping<span class='pagenum'><a name="Page_301" id="Page_301">[301]</a></span>
+greatly to overcome those troubles arising from boiler-incrustation
+which had prevented the rise of steam-pressure
+above about 25 pounds per square inch, and as, at the same
+time, it was learned by engineers that the deposit of lime-scale
+in the marine boiler was determined by temperature
+rather than by the degree of concentration, and that all the
+lime entering the boiler was deposited at the pressure just
+mentioned, a sudden advance took place. Careful design,
+good workmanship, and skillful management, made the surface-condenser
+an efficient apparatus; and, the dangers of
+incrustation being thus lessened, the movement toward
+higher pressures recommenced, and progressed so rapidly
+that now 75 pounds per square inch is very usual, and
+more than 125 pounds has since been attained.</p>
+
+<p>The close of this period was marked by the construction
+of the most successful types of paddle-steamers, the
+complete success of transoceanic steam-transportation, the
+introduction of the screw-propeller and the peculiar engine
+appropriate to it, and, finally, a general improvement, which
+had finally become marked both in direction and in rapidity
+of movement, leading toward the use of higher steam-pressure,
+greater expansion, lighter and more rapidly-working
+machinery, and decidedly better design and construction,
+and the use of better material. The result of these
+changes was seen in economy of first cost and maintenance,
+and the ability to attain greater speed, and to assure greater
+safety to passengers and less risk to cargo.</p>
+
+<p>The introduction of the changes just noted finally led
+to the last great change in the form of the marine steam-engine,
+and a revolution was inaugurated, which, however,
+only became complete in the succeeding period. The non-success
+of Hornblower and of Wolff, and others who had
+attempted to introduce the &#8220;compound&#8221; or double-cylinder
+engine on land, had not convinced all engineers that it
+might not yet be made a successful rival of the then standard
+type; and the three or four steamers which were built<span class='pagenum'><a name="Page_302" id="Page_302">[302]</a></span>
+for the Hudson River at the end of the first quarter of the
+nineteenth century are said to have been very successful
+vessels. Carrying 75 to 100 pounds of steam in their boilers,
+the Swiftsure and her contemporaries were by that circumstance
+well fitted to make that form of engine economically
+a success. This form of engine was built occasionally
+during the succeeding quarter of a century, but only became
+a recognized standard type after the close of the epoch to
+the history of which this chapter is devoted. That latest
+and greatest advance in the direction of increased efficiency
+in the marine steam-engine was, however, commenced very
+soon after Watt&#8217;s death, and its completion was the work
+of nearly a half-century.</p>
+
+<hr class="l05" />
+<div class="colleft">
+
+<div class="footnote"><p class="left"><a name="Footnote_58_58" id="Footnote_58_58"></a><a
+href="#FNanchor_58_58"><span class="label">[58]</span></a> &#8220;Steam and the Steam-Engine.&#8221;</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_59_59" id="Footnote_59_59"></a><a href="#FNanchor_59_59"><span class="label">[59]</span></a> &#8220;<a href="http://www.gutenberg.org/ebooks/3160">Odyssey</a>,&#8221; Book VIII., p. 175.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_60_60" id="Footnote_60_60"></a><a href="#FNanchor_60_60"><span class="label">[60]</span></a> <a href="http://www.gutenberg.org/ebooks/19406"><i>Scientific
+American</i>, February 24, 1877</a>.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_61_61" id="Footnote_61_61"></a><a href="#FNanchor_61_61"><span class="label">[61]</span></a> &#8220;Les Merveilles de la Science.&#8221;</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_62_62" id="Footnote_62_62"></a><a href="#FNanchor_62_62"><span class="label">[62]</span></a> &#8220;Some New Enquiries tending to the Improvement of Navigation.&#8221;
+London, 1760.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_63_63" id="Footnote_63_63"></a><a href="#FNanchor_63_63"><span class="label">[63]</span></a> <i>Lancaster Daily Express</i>, December 10, 1872. This account is collated
+from various manuscripts and letters in the possession of the author.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_64_64" id="Footnote_64_64"></a><a href="#FNanchor_64_64"><span class="label">[64]</span></a> Bowen&#8217;s &#8220;Sketches,&#8221; p. 56.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_65_65" id="Footnote_65_65"></a><a href="#FNanchor_65_65"><span class="label">[65]</span></a> Some of West&#8217;s portraits, including those of Mr. and Mrs. Henry,
+were lately in the possession of Mr. John Jordan, of Philadelphia.</p></div>
+
+<div class="footnote"><p><a name="Footnote_66_66" id="Footnote_66_66"></a><a href="#FNanchor_66_66"><span class="label">[66]</span></a> Figuier.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_67_67" id="Footnote_67_67"></a><a href="#FNanchor_67_67"><span class="label">[67]</span></a> &#8220;Life of John Fitch,&#8221; Westcott.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_68_68" id="Footnote_68_68"></a><a href="#FNanchor_68_68"><span class="label">[68]</span></a> <i>Rivington&#8217;s Gazette</i>, February 16, 1775.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_69_69" id="Footnote_69_69"></a><a href="#FNanchor_69_69"><span class="label">[69]</span></a> <i>Providence Journal</i>, May 7, 1874. Coll., N. H. Antiquar. Soc., No. 1;
+&#8220;Who invented the Steamboat?&#8221; William A. Mowry, 1874.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_70_70" id="Footnote_70_70"></a><a href="#FNanchor_70_70"><span class="label">[70]</span></a> Rev. Cyrus Mann, in the <i>Boston Recorder</i>, 1858.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_71_71" id="Footnote_71_71"></a><a href="#FNanchor_71_71"><span class="label">[71]</span></a> Westcott.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_72_72" id="Footnote_72_72"></a><a href="#FNanchor_72_72"><span class="label">[72]</span></a> This is substantially an arrangement that has recently become common.
+It has been repatented by later inventors.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_73_73" id="Footnote_73_73"></a><a href="#FNanchor_73_73"><span class="label">[73]</span></a> &#8220;Nathan Read and the Steam-Engine.&#8221;</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_74_74" id="Footnote_74_74"></a><a href="#FNanchor_74_74"><span class="label">[74]</span></a> &#8220;Encyclop&aelig;dia Americana.&#8221;</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_75_75" id="Footnote_75_75"></a><a href="#FNanchor_75_75"><span class="label">[75]</span></a> &#8220;A Lost Chapter in the History of the Steamboat,&#8221; J. H. B. Latrobe,
+1871.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_76_76" id="Footnote_76_76"></a><a href="#FNanchor_76_76"><span class="label">[76]</span></a> <i>Vide</i> &#8220;Life of Fulton,&#8221; Reigart.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_77_77" id="Footnote_77_77"></a><a href="#FNanchor_77_77"><span class="label">[77]</span></a> <i>Vide</i> &#8220;Life of Fulton,&#8221; Colden.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_78_78" id="Footnote_78_78"></a><a href="#FNanchor_78_78"><span class="label">[78]</span></a> A French inventor, a watchmaker of Tr&eacute;voux, named Desblancs, had
+already deposited at the Conservatoire a model fitted with &#8220;chaplets.&#8221;</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_79_79" id="Footnote_79_79"></a><a href="#FNanchor_79_79"><span class="label">[79]</span></a> Woodcroft, p. 64.</p></div>
+</div>
+
+<div class="footnote"><p class="left"><a name="Footnote_80_80" id="Footnote_80_80"></a><a href="#FNanchor_80_80"><span class="label">[80]</span></a> A newspaper-slip in the scrap-book of the author has the following:</p>
+
+<p>&#8220;The traveler of today, as he goes on board the great steamboats St.
+John or Drew, can scarcely imagine the difference between such floating
+palaces and the wee-bit punts on which our fathers were wafted 60 years
+ago. We may, however, get some idea of the sort of thing then in use by
+a perusal of the steamboat announcements of that time, two of which are as
+follows:</p>
+
+<p class="center">[&#8220;<i>Copy of an Advertisement taken from the Albany Gazette, dated September,
+1807.</i>]</p>
+
+<p>&#8220;The North River Steamboat will leave Pauler&#8217;s Hook Ferry [now Jersey
+City] on Friday, the 4th of September, at 9 in the morning, and arrive
+at Albany on Saturday, at 9 in the afternoon. Provisions, good berths,
+and accommodations are provided.
+</p>
+
+<p>&#8220;The charge to each passenger is as follows:</p>
+
+<table summary="Price List">
+
+<tr>
+<td class="left">&#8220;To</td>
+<td class="lr05">Newburg</td>
+<td class="center">dols.</td>
+<td class="right">3</td>
+<td class="left">,</td>
+<td class="center">time</td>
+<td class="right">14</td>
+<td class="center">hours.</td>
+</tr>
+
+<tr>
+<td class="center">&#8222;</td>
+<td class="lr05">Poughkeepsie</td>
+<td class="center">&#8222;</td>
+<td class="right">4</td>
+<td class="left">,</td>
+<td class="center">&#8222;</td>
+<td class="center">17</td>
+<td class="center">&#8222;</td>
+</tr>
+
+<tr>
+<td class="center">&#8222;</td>
+<td class="lr05">Esopus</td>
+<td class="center">&#8222;</td>
+<td class="right">5</td>
+<td class="left">,</td>
+<td class="center">&#8222;</td>
+<td class="center">20</td>
+<td class="center">&#8222;</td>
+</tr>
+
+<tr>
+<td class="center">&#8222;</td>
+<td class="lr05">Hudson</td>
+<td class="center">&#8222;</td>
+<td class="right">5</td>
+<td class="left"><span class="enum">1</span>&#8725;<span class="denom">2</span>,</td>
+<td class="center">&#8222;</td>
+<td class="center">30</td>
+<td class="center">&#8222;</td>
+</tr>
+
+<tr>
+<td class="center">&#8222;</td>
+<td class="lr05">Albany</td>
+<td class="center">&#8222;</td>
+<td class="right">7</td>
+<td class="left">,</td>
+<td class="center">&#8222;</td>
+<td class="center">36</td>
+<td class="center">&#8222;</td>
+</tr>
+
+</table>
+
+<p>&#8220;For places, apply to William Vandervoort, No. 48 Courtlandt Street,
+on the corner of Greenwich Street.</p>
+
+<p>&#8220;<i>September 2, 1807.</i></p>
+
+<p class="center">[&#8220;<i>Extract from the New York Evening Post, dated October 2, 1807.</i>]</p>
+
+<p>&#8220;Mr. Fulton&#8217;s new-invented <i>Steamboat</i>, which is fitted up in a neat style
+for passengers, and is intended to run from New York to Albany as a
+Packet, left here this morning with 90 passengers, against a strong head-wind.
+Notwithstanding which, it was judged she moved through the waters
+at the rate of six miles an hour.&#8221;</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_81_81" id="Footnote_81_81"></a><a href="#FNanchor_81_81"><span class="label">[81]</span></a> Bishop.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_82_82" id="Footnote_82_82"></a><a href="#FNanchor_82_82"><span class="label">[82]</span></a> <i>American Journal of Science</i>, March, 1827; <i>London Mechanics&#8217; Magazine</i>,
+June 16, 1827.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_83_83" id="Footnote_83_83"></a><a href="#FNanchor_83_83"><span class="label">[83]</span></a> &#8220;New Universal Cyclop&aelig;dia,&#8221; vol. iv., 1878.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_84_84" id="Footnote_84_84"></a><a href="#FNanchor_84_84"><span class="label">[84]</span></a> This distinguished inventor is still a resident of New York (1878).</p></div>
+
+<hr class="l05" />
+
+<div class="figcenter"><img src="images/illo329.png" alt="Ornament" width="250" height="270" /></div>
+
+<hr class="c40" /><p class='pagenum'><a name="Page_303" id="Page_303">[303]</a></p>
+
+<h2><a name="CHAPTER_VI" id="CHAPTER_VI"></a>CHAPTER VI.</h2>
+
+<h3><i>THE STEAM-ENGINE OF TO-DAY.</i></h3>
+<hr class="c05" />
+
+<div class="blockquot"><p>... &#8220;And, last of all, with inimitable power, and &#8216;with whirlwind
+sound,&#8217; comes the potent agency of steam. In comparison with the past,
+what centuries of improvement has this single agent comprised in the short
+compass of fifty years! Everywhere practicable, everywhere efficient, it has
+an arm a thousand times stronger than that of Hercules, and to which human
+ingenuity is capable of fitting a thousand times as many hands as
+belonged to Briareus. Steam is found in triumphant operation on the seas;
+and, under the influence of its strong propulsion, the gallant ship&mdash;</p>
+
+<div class="poem"><div class="stanza">
+<span class="i0">&#8216;Against the wind, against the tide,<br /></span>
+<span class="i2">Still steadies with an upright keel.&#8217;<br /></span>
+</div></div>
+
+<p>It is on the rivers, and the boatman may repose on his oars; it is on highways,
+and exerts itself along the courses of land-conveyance; it is at the
+bottom of mines, a thousand feet below the earth&#8217;s surface; it is in the
+mills, and in the workshops of the trades. It rows, it pumps, it excavates,
+it carries, it draws, it lifts, it hammers, it spins, it weaves, it prints. It
+seems to say to men, at least to the class of artisans: &#8216;Leave off your manual
+labor; give over your bodily toil; bestow but your skill and reason to the
+directing of my power, and I will bear the toil, with no muscle to grow weary,
+no nerve to relax, no breast to feel faintness!&#8217; What further improvement
+may still be made in the use of this astonishing power it is impossible to
+know, and it were vain to conjecture. What we do know is, that it has most
+essentially altered the face of affairs, and that no visible limit yet appears
+beyond which its progress is seen to be impossible.&#8221;&mdash;<span class="smcap">Daniel Webster.</span></p></div>
+<hr class="c05" />
+
+<h4><span class="smcap">The Period of Refinement&mdash;1850 to Date.</span></h4>
+<hr class="c05" />
+
+<p>By the middle of the present century, as we have now
+seen, the steam-engine had been applied, and successfully,
+to every great purpose for which it was fitted. Its first
+application was to the elevation of water; it next was applied
+to the driving of mills and machinery; and it finally<span class='pagenum'><a name="Page_304" id="Page_304">[304]</a></span>
+became the great propelling power in transportation by
+land and by sea.</p>
+
+<p>At the beginning of the period to which we are now
+come, these applications of steam-power had become familiar
+both to the engineer and to the public. The forms of
+engine adapted to each purpose had been determined, and
+had become usually standard. Every type of the modern
+steam-engine had assumed, more or less closely, the form
+and proportions which are now familiar; and the most
+intelligent designers and builders had been taught&mdash;by experience
+rather than by theory, for the theory of the steam-engine
+had then been but little investigated, and the principles
+and laws of thermo-dynamics had not been traced in
+their application to this engine&mdash;the principles of construction
+essential to successful practice, and were gradually
+learning the relative standing of the many forms of steam-engine,
+from among which have been preserved a few specially
+fitted for certain specific methods of utilization of
+power.</p>
+
+<p>During the years succeeding the date 1850, therefore,
+the growth of the steam-engine had been, not a change of
+standard type, or the addition of new parts, but a gradual
+improvement in forms, proportions, and arrangements of
+details; and this period has been marked by the dying out
+of the forms of engine least fitted to succeed in competition
+with others, and the retention of the latter has been an example
+of &#8220;the survival of the fittest.&#8221; This has therefore
+been a Period of Refinement.</p>
+
+<p>During this period invention has been confined to details;
+it has produced new forms of parts, new arrangements
+of details; it has devised an immense variety of
+valves, valve-motions, regulating apparatus, and a still
+greater variety of steam-boilers and of attachments, essential
+and non-essential, to both engines and boilers. The
+great majority of these peculiar devices have been of no
+value, and very many of the best of them have been found<span class='pagenum'><a name="Page_305" id="Page_305">[305]</a></span>
+to have about equal value. All the well-known and successful
+forms of engine, when equally well designed and constructed
+and equally well managed, are of very nearly equal
+efficiency; all of the best-known types of steam-boiler,
+where given equal proportions of grate to heating-surface
+and equally well designed, with a view to securing a good
+draught and a good circulation of water, have been found
+to give very nearly equally good results; and it has become
+evident that a good knowledge of principles and of
+practice, on the part of the designer, the constructor, and
+the manager of the boiler, is essential in the endeavor to
+achieve economical success; that good engineering is demanded,
+rather than great ingenuity. The inventor has
+been superseded here by the engineer.</p>
+
+<p>The knowledge acquired in the time of Watt, of the
+essential principles of steam-engine construction, has since
+become generally familiar to the better class of engineers.
+It has led to the selection of simple, strong, and durable
+forms of engine and boiler, to the introduction of various
+kinds of valves and of valve-gearing, capable of adjustment
+to any desired range of expansive working, and to the attachment
+of efficient forms of governor to regulate the speed of
+the engine, by determining automatically the point of cut-off
+which will, at any instant, best adjust the energy exerted
+by the expanding steam to the demand made by the work
+to be done.</p>
+
+<p>The value of high pressures and considerable expansion
+was recognized as long ago as in the early part of the present
+century, and Watt, by combining skillfully the several
+principal parts of the steam-engine, gave it very nearly
+the shape which it has to-day. The compound engine,
+even, as has been seen, was invented by contemporaries of
+Watt, and the only important modifications since his time
+have occurred in details. The introduction of the &#8220;drop
+cut-off,&#8221; the attachment of the governor to the expansion-apparatus
+in such a manner as to determine the degree of<span class='pagenum'><a name="Page_306" id="Page_306">[306]</a></span>
+expansion, the improvement of proportions, the introduction
+of higher steam and greater expansion, the improvement of
+the marine engine by the adoption of surface-condensation,
+in addition to these other changes, and the introduction of
+the double-cylinder engine, after the elevation of steam-pressure
+and increase of expansion had gone so far as to
+justify its use, are the changes, therefore, which have taken
+place during this last quarter-century. It began then to be
+generally understood that expansion of steam produced
+economy, and mechanics and inventors vied with each other
+in the effort to obtain a form of valve-gear which should
+secure the immense saving which an abstract consideration
+of the expansion of gases according to Marriotte&#8217;s law
+would seem to promise. The counteracting phenomena of
+internal condensation and re&euml;vaporation, of the losses of
+heat externally and internally, and of the effect of defective
+vacuum, defective distribution of steam, and of back-pressure,
+were either unobserved or were entirely overlooked.</p>
+
+<p>It was many years, therefore, before engine-builders became
+convinced that no improvement upon existing forms
+of expansion-gear could secure even an approximation to
+theoretical efficiency.</p>
+
+<p>The fact thus learned, that the benefit of expansive
+working has a limit which is very soon reached in ordinary
+practice, was not then, and has only recently become, generally
+known among our steam-engine builders, and for
+several years, during the period upon which we now enter,
+there continued the keenest competition between makers of
+rival forms of expansion-gear, and inventors were continually
+endeavoring to produce something which should far
+excel any previously-existing device.</p>
+
+<p>In Europe, as in the United States, efforts to &#8220;improve&#8221;
+standard designs have usually resulted in injuring their
+efficiency, and in simply adding to the first cost and running
+expense of the engines, without securing a marked
+increase in economy in the consumption of steam.</p>
+
+<hr class="c05" />
+<p class='pagenum'><a name="Page_307" id="Page_307">[307]</a></p>
+<h4><span class="smcap">Section I.&mdash;Stationary Engines.</span></h4>
+<hr class="c05" />
+
+<p>&#8220;<span class="smcap">Stationary Engines</span>&#8221; had been applied to the operation
+of mill-machinery, as has been seen, by Watt and by
+Murdoch, his assistant and pupil; and Watt&#8217;s competitors,
+in Great Britain and abroad, had made considerable progress
+before the death of the great engineer, in its adaptation to
+its work. In the United States, Oliver Evans had introduced
+the non-condensing high-pressure stationary engine,
+which was the progenitor of the standard engine of that type
+which is now used far more generally than any other form.
+These engines were at first rude in design, badly proportioned,
+rough and inaccurate as to workmanship, and uneconomical
+in their consumption of fuel. Gradually, however,
+when made by reputable builders, they assumed neat and
+strong shapes, good proportions, and were well made and
+of excellent materials, doing their work with comparatively
+little waste of heat or of fuel.</p>
+
+<div class="figcenter"><a name="Fig93" id="Fig93"></a>
+<img src="images/illo335.png" alt="Vertical Stationary Engine" width="263" height="500" />
+<p class="caption"><span class="smcap">Fig. 93.</span>&mdash;Vertical Stationary Steam-Engine.</p></div>
+
+<p>One of the neatest and best modern designs of stationary
+engine for small powers is seen in <a href="#Fig93">Fig. 93</a>, which represents
+a &#8220;vertical direct-acting engine,&#8221; with base-plate&mdash;a
+form which is a favorite with many engineers.</p>
+
+<p>The engine shown in the engraving consists of two principal
+parts, the cylinder and the frame, which is a tapering
+column having openings in the sides, to allow free access
+to all the working parts within. The slides and pillow-blocks
+are cast with the column, so that they cannot become
+loose or out of line; the rubbing surfaces are large
+and easily lubricated. Owing to the vertical position, there
+is no tendency to side wear of cylinder or piston. The
+packing-rings are self-adjusting, and work free but tight.
+The crank is counterbalanced; the crank-pin, cross-head pin,
+piston-rod, valve-stem, etc., are made of steel; all the bearing
+surfaces are made extra large, and are accurately fitted;
+and the best quality of Babbitt-metal only used for the
+journal-bearings.</p>
+
+<p><span class='pagenum'><a name="Page_308" id="Page_308">[308]</a></span>The smaller sizes of these engines, from 2 to 10 horse-power,
+have both pillow-blocks cast in the frame, giving a
+bearing each side of the double cranks. They are built by
+some constructors in quantities, and parts duplicated by<span class='pagenum'><a name="Page_309" id="Page_309">[309]</a></span>
+special machinery (as in fire-arms and sewing-machines),
+which secures great accuracy and uniformity of workmanship,
+and allows of any part being quickly and cheaply
+replaced, when worn or broken by accident. The next figure
+is a vertical section through the same engine.</p>
+
+<div class="figcenter"><a name="Fig94" id="Fig94"></a>
+<img src="images/illo336.png" alt="Vertical Stationary Engine, Section" width="350" height="454" />
+<p class="caption"><span class="smcap">Fig. 94.</span>&mdash;Vertical Stationary Steam-Engine. Section.</p></div>
+
+<p>Engines fitted with the ordinary rigid bearings require
+to be erected on a firm foundation, and to be kept in perfect
+line. If, by the settling of the foundation, or from any
+other cause, they get out of line, heating, cutting, and
+thumping result. To obviate this, modern engines are often
+fitted with self-adjusting bearings throughout; this gives
+the engine great flexibility and freedom from friction. The
+accompanying cuts show clearly how this is accomplished.<span class='pagenum'><a name="Page_310" id="Page_310">[310]</a></span>
+The pillow-block has a spherical shell turned and fitted into
+the spherically-bored pillow-block, thus allowing a slight
+angular motion in any direction. The connecting-rod is
+forged in a single piece, without straps, gibs, or key, and is
+mortised through at each end for the reception of the brass
+boxes, which are curved on their backs, and fit the cheek-pieces,
+between which they can turn to adjust themselves
+to the pins, in the plane of the axis of the rod. The adjustment
+for wear is made by wedge-blocks and set screws,
+as shown, and they are so constructed that the parts cannot
+get loose and cause a break-down. The cross-head has
+adjustable gibs on each side, turned to fit the slides, which
+are cast solidly in the frame, and bored out exactly in the
+line with the cylinder. This permits it freely to turn on its
+axis, and, in connection with the adjustable boxes in the
+connecting-rod, allows a perfect self-adjustment to the line of
+the crank-pin. The out-board bearing may be moved an inch
+or more out of position in any direction, without detriment to
+the running of the engine, all bearings accommodating themselves
+perfectly to whatever position the shaft may assume.</p>
+
+<p>The ports and valve-passages are proportioned as in
+locomotive practice. The valve-seat is adapted to the ordinary
+plain slide or D-valve, should it be preferred, but the
+balanced piston slide-valve works with equal ease whether
+the steam-pressure is 10 or 100 pounds, and at the same time
+gives double steam and exhaust openings, which greatly facilitates
+the entrance of the steam to, and its escape from, the
+cylinder, thus securing a nearer approach to boiler-pressure
+and a less back-pressure, saving the power required to work
+an ordinary valve, and reducing the wear of valve-gear.</p>
+
+<p>This is a type of engine frequently seen in the United
+States, but more rarely in Europe. It is an excellent form
+of engine. The vertical direct-acting engine is sometimes,
+though rarely, built of very considerable size, and these
+large engines are more frequently seen in rolling-mills than
+elsewhere.<span class='pagenum'><a name="Page_311" id="Page_311">[311]</a></span></p>
+
+<p>Where much power is required, the stationary engine is
+usually an horizontal direct-acting engine, having a more
+or less effective cut-off valve-gear, according to the size of
+engine and the cost of fuel. A good example of the simpler
+form of this kind of engine is the small horizontal
+slide-valve engine, with independent cut-off valve riding on
+the back of the main valve&mdash;a combination generally known
+among engineers as the Meyer system of valve-gear. This
+form of steam-engine is a very effective machine, and does
+excellent work when properly proportioned to yield the required
+amount of power. It is well adapted to an expansion
+of from four to five times. Its disadvantages are the
+difficulty which it presents in the attachment of the regulator,
+to determine the point of cut-off by the heavy work
+which it throws upon the governor when attached, and the
+rather inflexible character of the device as an expansive
+valve-gear. The best examples of this class of engine have
+neat heavy bed-plates, well-designed cylinders and details,
+smooth-working valve-gear, the expansion-valve adjusted
+by a right and left hand screw, and regulation secured by
+the attachment of the governor to the throttle-valve.</p>
+
+<div class="figcenter"><a name="Fig95" id="Fig95"></a>
+<img src="images/illo339.png" alt="Horizontal Stationary Steam-Engine" width="484" height="300" />
+<p class="caption"><span class="smcap">Fig. 95.</span>&mdash;Horizontal Stationary Steam-Engine.</p></div>
+
+<p>The engine shown in the accompanying illustration
+(<a href="#Fig95">Fig. 95</a>) is an example of an excellent British stationary
+steam-engine. It is simple, strong, and efficient. The
+frame, front cylinder-head, cross-head guides, and crank-shaft
+&#8220;plumber-block,&#8221; are cast in one piece, as has so
+generally been done in the United States for a long time
+by some of our manufacturers. The cylinder is secured
+against the end of the bed-plate, as was first done by Corliss.
+The crank-pin is set in a counterbalanced disk. The
+valve-gear is simple, and the governor effective, and provided
+with a safety-device to prevent injury by the breaking
+of the governor-belt. An engine of this kind of 10
+inches diameter of cylinder, 20 inches stroke of piston, is
+rated by the builders at about 25 horse-power; a similar
+engine 30 inches in diameter of cylinder would yield from<span class='pagenum'><a name="Page_312" id="Page_312">[312-313]</a></span>
+<span class='pagenum'><a name="Page_313" id="Page_313"></a></span>225 to 250 horse-power. In this example, all parts are made
+to exact size by gauges standardized to Whitworth&#8217;s sizes.</p>
+
+<div class="figcenter"><a name="Fig96" id="Fig96"></a>
+<img src="images/illo340.png" alt="Horizontal Stationary Steam-Engine" width="550" height="300" />
+<p class="caption"><span class="smcap">Fig. 96.</span>&mdash;Horizontal Stationary Steam-Engine.</p></div>
+
+<p>In American engines (as is seen in <a href="#Fig96">Fig. 96</a>), usually, two
+supports are placed&mdash;the one under the latter bearing, and
+the other under the cylinder&mdash;to take the weight of the engine;
+and through them it is secured to the foundation.
+As in the vertical engine already described, a valve is
+sometimes used, consisting of two pistons connected by a<span class='pagenum'><a name="Page_314" id="Page_314">[314]</a></span>
+rod, and worked by an ordinary eccentric. By a simple
+arrangement these pistons have always the same pressure inside
+as out, which prevents any leakage or blowing through;
+and they are said always to work equally as well and free
+from friction under 150 pounds pressure as under 10 pounds
+per square inch, and to require no adjustment. It is more
+usual, however, to adopt the three-ported valve used on
+locomotives, with (frequently) a cut-off valve on the back
+of this main valve, which cut-off valve is adjusted either
+by hand or by the governor.</p>
+
+<p>Engines of the class just described are especially well
+fitted, by their simplicity, compactness, and solidity, to
+work at the high piston-speeds which are gradually becoming
+generally adopted in the effort to attain increased
+economy of fuel by the reduction of the immense losses of
+heat which occur in the expansion of steam in the metallic
+cylinders through which we are now compelled to work it.</p>
+
+<p>One of the best known of recent engines is the Allen
+engine, a steam-engine having the same general arrangement
+of parts seen in the above illustration, but fitted with
+a peculiar valve-gear, and having proportions of parts which
+are especially calculated to secure smoothness of motion
+and uniformity of pressure on crank-pin and journals, at
+speeds so high that the inertia of the reciprocating parts
+becomes a seriously-important element in the calculation of
+the distribution of stresses and their effect on the dynamics
+of the machine.</p>
+
+<p>In the Allen engine,<a name="FNanchor_85_85" id="FNanchor_85_85"></a><a href="#Footnote_85_85" class="fnanchor">[85]</a> the cylinder and frame are connected
+as in the engine seen above, and the crank-disk,
+shaft-bearings, and other principal details, are not essentially
+different. The valve-gear<a name="FNanchor_86_86" id="FNanchor_86_86"></a><a href="#Footnote_86_86" class="fnanchor">[86]</a> differs in having four valves,
+one at each end on the steam as well as on the exhaust side,
+all of which are balanced and work with very little resistance.
+These valves are not detachable, but are driven by<span class='pagenum'><a name="Page_315" id="Page_315">[315]</a></span>
+a link attached to and moved by an eccentric on the main
+shaft, the position of the valve-rod attachment to which
+link is determined by the governor, and the degree of expansion
+is thus adjusted to the work of the engine. The
+engine has usually a short stroke, not exceeding twice the
+diameter of cylinder, and is driven at very high speed, generally
+averaging from 600 to 800 feet per minute.<a name="FNanchor_87_87" id="FNanchor_87_87"></a><a href="#Footnote_87_87" class="fnanchor">[87]</a> This
+high piston-speed and short stroke give very great velocity
+of rotation. The effect is, therefore, to produce an exceptional
+smoothness of motion, while permitting the use of
+small fly-wheels. Its short stroke enables entire solidity to
+be attained in a bed of rigid form, making it a very completely
+self-contained engine, adapted to the heaviest work,
+and requiring only a small foundation.</p>
+
+<p>The journals of the shaft, and all cylindrical wearing
+surfaces, are finished by grinding in a manner that leaves
+them perfectly round. The crank-pin and cross-head pin
+are hardened before being ground. The joints of the valve-gear
+consist of pins turning in solid ferrules in the rod-ends,
+both hardened and ground. After years of constant use
+thus, no wear occasioning lost time in the valve-movements
+has been detected.</p>
+
+<p>High speed and short strokes are essential elements of
+economy. It is now well understood that all the surfaces
+with which the steam comes in contact condense it.</p>
+
+<p>Obviously, one way to diminish this loss is to reduce the
+extent of surface to which the steam is exposed. In engines
+of high speed and short stroke, the surfaces with which the
+steam comes in contact, while doing a given amount of
+work, present less area than in ordinary engines running at
+low speed. Where great steadiness of motion is desired,
+the expense of coupled engines is often incurred. Quick-running
+engines do not require to be coupled; a single
+engine may give greater uniformity of motion than is usually<span class='pagenum'><a name="Page_316" id="Page_316">[316]</a></span>
+obtained with coupled engines at ordinary speeds. The
+ports and valve-movements, the weight of the reciprocating
+parts, and the size and weight of the fly-wheels, should be
+calculated expressly for the speeds chosen.</p>
+
+<p>The economy of the engine here described is unexcelled
+by the best of the more familiar &#8220;drop cut-off&#8221; engines.</p>
+
+<p>An engine reported upon by a committee of the American
+Institute, of which Dr. Barnard was chairman, was
+non-condensing, 16 inches in diameter of cylinder, 30 inches
+stroke, making 125 revolutions per minute, and developed
+over 125 horse-power with 75 pounds of steam in the boiler,
+using 25<span class="enum">3</span>&#8725;<span class="denom">4</span> pounds of steam per indicated horse-power, and
+2.87 pounds of coal&mdash;an extraordinarily good performance
+for an engine of such small power.</p>
+
+<p>The governor used on this engine is known as the Porter
+governor. It is given great power and delicacy by
+weighting it down, and thus obtaining a high velocity of
+rotation, and by suspending the balls from forked arms,
+which are given each two bearing-pins separated laterally
+so far as to permit considerable force to be exerted in
+changing speeds without cramping those bearings sufficiently
+to seriously impair the sensitiveness of the governor.
+This engine as a whole may be regarded as a good representative
+of the high-speed engine of to-day.</p>
+
+<p>Since this change in the direction of high speeds has
+already gone so far that the &#8220;drop cut-off&#8221; is sometimes
+inapplicable, in consequence of the fact that the piston
+would, were such a valve-gear adopted, reach the end of
+its stroke before the detached valve could reach its seat;
+and since this progress is only limited by our attainments
+in mechanical skill and accuracy, it seems probable that
+the &#8220;positive-motion expansion-gear&#8221; type of engine will
+ultimately supersede the now standard &#8220;drop cut-off engine.&#8221;</p>
+
+<p>The best known and most generally used class of stationary
+engines at the present time is, however, that which<span class='pagenum'><a name="Page_317" id="Page_317">[317]</a></span>
+has the so-called &#8220;drop cut-off,&#8221; or &#8220;detachable valve-gear.&#8221;
+The oldest well-known form of valve-motion of this description
+now in use is that known as the Sickels cut-off,
+patented by Frederick E. Sickels, an American mechanic,
+about the year 1841, and also built by Hogg, of New York,
+who placed it upon the engine of the steamer South America.
+The invention is claimed for both Hogg and Sickels.
+It was introduced by the inventor in a form which especially
+adapted it to use with the beam-engine used on the
+Eastern waters of the United States, and was adapted to
+stationary engines by Messrs. Thurston, Greene &amp; Co., of
+Providence, R. I., who made use of it for some years before
+any other form of &#8220;drop cut-off&#8221; came into general use.
+The Sickels cut-off consisted of a set of steam-valves, usually
+independent of the exhaust-valves, and each raised by
+a catch, which could be thrown out, at the proper moment,
+by a wedge with which it came in contact as it rose with
+the opening valve. This wedge, or other equivalent device,
+was so adjusted that the valve should be detached and fall to
+its seat when the piston reached that point in its movement,
+after taking steam, at which expansion was to commence.
+From this point, no steam entering the cylinder, the piston
+was impelled by the expanding vapor. The valve was usually
+the double-poppet. Sickels subsequently invented what
+was called the &#8220;beam-motion,&#8221; to detach the valve at any
+point in the stroke. As at first arranged, the valve could
+only be detached during the earlier half-stroke, since at
+mid-stroke the direction of motion of the eccentric rod was
+reversed and the valve began to descend. By introducing a
+&#8220;wiper&#8221; having a motion transverse to that of the valve
+and its catch, and by giving this wiper a motion coincident
+with that of the piston by connecting it with the beam or
+other part of the engine moving with the piston, he obtained
+a kinematic combination which permitted the valve
+to be detached at any point in the stroke, adding a very
+simple contrivance which enabled the attendant to set the<span class='pagenum'><a name="Page_318" id="Page_318">[318]</a></span>
+wiper so that it should strike the catch at any time during
+the forward movement of the &#8220;beam-motion.&#8221;</p>
+
+<p>On stationary engines, the point of cut-off was afterward
+determined by the governor, which was made to operate
+the detaching mechanism, the combination forming what
+is sometimes called an &#8220;automatic&#8221; cut-off. The attachment
+of the governor so as to determine the degree of expansion
+had been proposed before Sickels&#8217;s time. One of
+the earliest of these contrivances was that of Zachariah
+Allen, in 1834, using a cut-off valve independent of the
+steam-valve. The first to so attach the governor to a <i>drop
+cut-off</i> valve-motion was George H. Corliss, who made it
+a feature of the Corliss valve-gear in 1849. In the year
+1855, N. T. Greene introduced a form of expansion-gear,
+in which he combined the range of the Sickels beam-motion
+device with the expansion-adjustment gained by the attachment
+of the governor, and with the advantages of flat slide-valves
+at all ports&mdash;both steam and exhaust.</p>
+
+<p>Many other ingenious forms of expansion valve-gear
+have been invented, and several have been introduced,
+which, properly designed and proportioned to well-planned
+engines, and with good construction and management,
+should give economical results little if at all inferior to
+those just named. Among the most ingenious of these
+later devices is that of Babcock &amp; Wilcox, in which a very
+small auxiliary steam-cylinder and piston is employed to
+throw the cut-off valve over its port at the instant at which
+the steam is to be cut off. A very beautiful form of isochronous
+governor is used on this engine, to regulate the
+speed of the engine by determining the point of cut-off.</p>
+
+<p>In Wright&#8217;s engine, the expansion is adjusted by the
+movement, by the regulator, of cams which operate the
+steam-valves so that they shall hold the valve open a longer
+or shorter time, as required.</p>
+
+<p>Since compactness and lightness are not as essential as
+in portable, locomotive, and marine engines, the parts are<span class='pagenum'><a name="Page_319" id="Page_319">[319]</a></span>
+arranged, in stationary engines, with a view simply to securing
+efficiency, and the design is determined by circumstances.
+It was formerly usual to adopt the condensing
+engine in mills, and wherever a stationary engine was required.
+In Europe generally, and to some extent in the
+United States, where a supply of condensing water is obtainable,
+condensing engines and moderate steam-pressures
+are still employed. But this type of engine is gradually
+becoming superseded by the high-pressure condensing engine,
+with considerable expansion, and with an expansion-gear
+in which the point of cut-off is determined by the
+governor.</p>
+
+<div class="figcenter"><a name="Fig97" id="Fig97"></a>
+<img src="images/illo346.png" alt="Corliss Engine" width="476" height="350" />
+<p class="caption"><span class="smcap">Fig. 97.</span>&mdash;Corliss Engine.</p></div>
+
+<div class="figcenter"><a name="Fig98" id="Fig98"></a>
+<img src="images/illo347.png" alt="Corliss Engine Valve-Motion" width="350" height="378" />
+<p class="caption"><span class="smcap">Fig. 98</span>&mdash;Corliss Engine Valve-Motion.</p></div>
+
+<p>The best-known engine of this class is the Corliss engine,
+which is very extensively used in the United States,
+and which has been copied very generally by European
+builders. <a href="#Fig97">Fig. 97</a> represents the Corliss engine. The
+horizontal steam-cylinder is bolted firmly to the end of the
+frame, which is so formed as to transmit the strain to the
+main journal with the greatest directness. The frame carries
+the guides for the cross-head, which are both in the
+same vertical plane. The valves are four in number, a
+steam and an exhaust valve being placed at each end of the
+steam-cylinder. Short steam-passages are thus secured, and<span class='pagenum'><a name="Page_320" id="Page_320">[320]</a></span>
+this diminution of clearance is a source of some economy.
+Both sets of valves are driven by an eccentric operating a
+disk or wrist-plate, <i>E</i> (<a href="#Fig98">Fig. 98</a>), which vibrates on a pin projecting
+from the cylinder. Short links reaching from this
+wrist-plate to the several valves, <i>D D</i>, <i>F F</i>, move them with
+a peculiarly varying motion, opening and closing them rapidly,
+and moving them quite slowly when the port is either
+nearly open or almost closed. This effect is ingeniously
+secured by so placing the pins on the wrist-plate that their
+line of motion becomes nearly transverse to the direction of
+the valve-links when the limit of movement is approached.
+The links connecting the wrist-plate with the arms moving
+the steam-valves have catches at their extremities, which
+are disengaged by coming in contact, as the arm swings
+around with the valve-stem, with a cam adjusted by the
+governor. This adjustment permits the steam to follow the
+piston farther when the engine is caused to &#8220;slow down,&#8221;
+and thus tends to restore the proper speed. It disengages
+the steam-valve earlier, and expands the steam to a greater<span class='pagenum'><a name="Page_321" id="Page_321">[321]</a></span>
+extent, when the engine begins to run above the proper
+speed. When the catch is thrown out, the valve is closed
+by a weight or a strong spring. To prevent jar when the
+motion of the valve is checked, a &#8220;dash-pot&#8221; is used, invented
+originally by F. E. Sickels. This is a vessel having
+a nicely-fitted piston, which is received by a &#8220;cushion&#8221; of
+water or air when the piston suddenly enters the cylinder
+at the end of the valve-movement. In the original water
+dash-pot of Sickels, the cylinder is vertical, and the plunger
+or piston descends upon a small body of water confined in
+the base of the dash-pot. Corliss&#8217;s air dash-pot is now often
+set horizontally.</p>
+
+<div class="figcenter"><a name="Fig99" id="Fig99"></a>
+<img src="images/illo348.png" alt="Greene Engine" width="350" height="460" />
+<p class="caption"><span class="smcap">Fig. 99.</span>&mdash;Greene Engine.</p></div>
+
+<p>In the Greene steam-engine (<a href="#Fig99">Fig. 99</a>), the valves
+are<span class='pagenum'><a name="Page_322" id="Page_322">[322]</a></span>
+four in number, as in the Corliss. The cut-off gear consists
+of a bar, <i>A</i>, moved by the steam-eccentric in a direction
+parallel with the centre-line of the cylinder and nearly coincident
+as to time with the piston. On this bar are tappets,
+<i>C C</i>, supported by springs and adjustable in height by
+the governor, <i>G</i>. These tappets engage the arms <i>B B</i>, on
+the ends of rock-shafts, <i>E E</i>, which move the steam-valves
+and remain in contact with them a longer or shorter time,
+and holding the valve open during a greater or less part of
+the piston-stroke, as the governor permits the tappets to
+rise with diminishing engine-speed, or forces them down as
+speed increases. The exhaust-valves are moved by an independent
+eccentric rod, which is itself moved by an eccentric
+set, as is usual with the Corliss and with other engines
+generally, at right angles with the crank. This engine, in
+consequence of the independence of the steam-eccentric,
+and of the contemporary movement of steam valve-motion
+and steam-piston, is capable of cutting off at any point
+from beginning to nearly the end of the stroke. The usual
+arrangement, by which steam and exhaust valves are moved
+by the same eccentric, only permits expansion with the
+range from the beginning to half-stroke. In the Corliss
+engine the latter construction is retained, with the object,
+in part, of securing a means of closing the valve by a &#8220;positive
+motion,&#8221; should, by any accident, the closing not be
+effected by the weight or spring usually relied upon.</p>
+
+<div class="figcenter"><a name="Fig100" id="Fig100"></a>
+<img src="images/illo349.png" alt="Greene-Engine Valve-Gear" width="350" height="235" />
+<p class="caption"><span class="smcap">Fig. 100.</span>&mdash;Thurston&#8217;s Greene-Engine Valve-Gear.</p></div>
+
+<p><span class='pagenum'><a name="Page_323" id="Page_323">[323]</a></span>The steam-valve of the Greene engine, as designed by
+the author, is seen in <a href="#Fig100">Fig. 100</a>, where the valve, <i>G H</i>, covering
+the port, <i>D</i>, in the steam-cylinder, <i>A B</i>, is moved by
+the rod, <i>J J</i>, connected to the rock-shaft, <i>M</i>, by the arm,
+<i>L K</i>. The line, <i>K I</i>, should, when carried out, intersect
+the valve-face at its middle point, under <i>G</i>.</p>
+
+<p>The characteristics of the American stationary engine,
+therefore, are high steam-pressure without condensation, an
+expansion valve-gear with drop cut-off adjustable by the
+governor, high piston-speed, and lightness combined with
+strength of construction. The pressure most commonly
+adopted in the boilers which furnish steam to this type of
+engine is from 75 to 80 pounds per square inch; but a
+pressure of 100 pounds is not infrequently carried, and the
+latter pressure may be regarded as a &#8220;mean maximum,&#8221;
+corresponding to a pressure of 60 pounds at about the
+commencement of the period here considered&mdash;1850.</p>
+
+<p>Very much greater pressures have, however, been adopted
+by some makers, and immensely &#8220;higher steam&#8221; has
+been experimented with by several engineers. As early as
+1823, Jacob Perkins<a name="FNanchor_88_88" id="FNanchor_88_88"></a><a
+href="#Footnote_88_88" class="fnanchor">[88]</a> commenced experimenting with steam
+of very great tension. As has already been stated, the usual
+pressure at the time of Watt was but a few pounds&mdash;5 or
+7&mdash;in excess of that of the atmosphere. Evans, Trevithick,
+and Stevens, had previously worked steam at pressures of
+from 50 to 75 pounds per square inch, and pressures on the
+Western rivers and elsewhere in the United States had already
+been raised to 100 or 150 pounds, and explosions were
+becoming alarmingly frequent.</p>
+
+<p>Perkins&#8217;s experimental apparatus consisted of a copper
+boiler, of a capacity of about one cubic foot, having sides
+3 inches in thickness. It was closed at the bottom and
+top, and had five small pipes leading from the upper head.<span class='pagenum'><a name="Page_324" id="Page_324">[324]</a></span>
+This was placed in a furnace kept at a high temperature by
+a forced combustion. Safety-valves loaded respectively to
+425 and 550 pounds per square inch were placed on each of
+two of the steam-pipes.</p>
+
+<p>Perkins used the steam generated under these great
+pressures in a little engine having a piston 2 inches in diameter
+and a stroke of 1 foot. It was rated at 10 horse-power.<a name="FNanchor_89_89"
+id="FNanchor_89_89"></a><a href="#Footnote_89_89" class="fnanchor">[89]</a></p>
+
+<p>In the year 1827, Perkins had attained working pressures,
+in a single-acting, single-cylinder engine, of upward
+of 800 pounds per square inch. At pressures exceeding 200
+pounds, he had much trouble in securing effective lubrication,
+as all oils charred and decomposed at the high temperatures
+then unavoidably encountered, and he finally succeeded
+in evading this seemingly insurmountable obstacle
+by using for rubbing parts a peculiar alloy which required
+no lubrication, and which became so beautifully polished,
+after some wear, that the friction was less than where lubricants
+were used. At these high pressures Perkins seems
+to have met with no other serious difficulty. He condensed
+the exhaust-steam and returned it to the boiler, but did not
+attempt to create a vacuum in his condenser, and therefore
+needed no air-pump. Steam was cut off at one-eighth
+stroke.</p>
+
+<p>In the same year, Perkins made a compound engine on
+the Woolf plan, and adopted a pressure of 1,400 pounds, expanding<span class='pagenum'><a name="Page_325" id="Page_325">[325]</a></span>
+eight times. In still another engine, intended for a
+steam-vessel, Perkins adopted, or proposed to adopt, 2,000
+pounds pressure, cutting off the admission at one-sixteenth,
+in single-acting engines of 6 inches diameter of cylinder
+and 20 inches stroke of piston. The steam did not retain
+boiler-pressure at the cylinder, and this engine was only
+rated at 30 horse-power.<a name="FNanchor_90_90" id="FNanchor_90_90"></a><a href="#Footnote_90_90" class="fnanchor">[90]</a></p>
+
+<p>Stuart follows a description of Perkins&#8217;s work in the
+improvement of the steam-engine and the introduction of
+steam-artillery by the remark:</p>
+
+<p>&#8220; ... No other mechanic of the day has done more
+to illustrate an obscure branch of philosophy by a series of
+difficult, dangerous, and expensive experiments; no one&#8217;s
+labors have been more deserving of cheering encouragement,
+and no one has received less. Even in their present
+state, his experiments are opening new fields for philosophical
+research, and his mechanism bids fair to introduce a
+new style into the proportions, construction, and form, of
+steam-machinery.&#8221;</p>
+
+<p>Perkins&#8217;s experience was no exception to the general
+rule, which denies to nearly all inventors a fair return for
+the benefits which they confer upon mankind.</p>
+
+<p>Another engineer, a few years later, was also successful
+in controlling and working steam under much higher pressures
+than are even now in use. This was Dr. Ernst Alban,
+a distinguished German engine-builder, of Plau, Mecklenburg,
+and an admirer of Oliver Evans, in whose path he, a
+generation later, advanced far beyond that great pioneer.
+Writing in 1843, he describes a system of engine and boiler
+construction, with which he used steam under pressures
+about equal to those experimentally worked by Jacob Perkins,
+Evans&#8217;s American successor. Alban&#8217;s treatise was
+translated and printed in Great Britain,<a name="FNanchor_91_91"
+id="FNanchor_91_91"></a><a href="#Footnote_91_91" class="fnanchor">[91]</a> four years later.</p>
+
+<p><span class='pagenum'><a name="Page_326" id="Page_326">[326]</a></span>Alban, on one occasion, used steam of 1,000 pounds
+pressure. His boilers were similar in general form to the
+boiler patented by Stevens in 1805, but the tubes were horizontal
+instead of vertical. He evaporated from 8 to 10
+pounds of water into steam of 600 to 800 pounds pressure
+with each pound of coal. He states that the difficulty met
+by Perkins&mdash;the decomposition of lubricants in the steam-cylinder&mdash;did
+not present itself in his experiments, even
+when working steam at a pressure of 600 pounds on the
+square inch, and he found that less lubrication was needed
+at such high pressures than in ordinary practice. Alban
+expanded his steam about as much as Evans, in his usual
+practice, carrying a pressure of 150 pounds, and cutting off
+at one-third; he adopted greatly increased piston-speed, attaining
+300 feet per minute, at a time when common practice
+had only reached 200 feet. He usually built an oscillating
+engine, and rarely attached a condenser. The valve was the
+locomotive-slide.<a name="FNanchor_92_92" id="FNanchor_92_92"></a><a
+href="#Footnote_92_92" class="fnanchor">[92]</a> The stroke was made short to secure
+strength, compactness, cheapness, and high speed of rotation;
+but Alban does not seem to have understood the
+principles controlling the form and proportions of the expansive
+engine, or the necessity of adopting considerable
+expansion in order to secure economy in working steam of
+great tension, and therefore was, apparently, not aware of
+the advantages of a long stroke in reducing losses by &#8220;dead-space,&#8221;
+in reducing risk of annoyance by hot journals, or in
+enabling high piston-speeds to be adopted. He seems
+never to have attained a sufficiently high speed of piston to
+become aware that the oscillating cylinder cannot be used
+at speeds perfectly practicable with the fixed cylinder.</p>
+
+<p>Alban states that one of his smallest engines, having a
+cylinder 4<span class="enum">1</span>&#8725;<span class="denom">2</span> inches in diameter and 1 foot stroke of piston,
+with a piston-speed of but 140 to 160 feet per minute, developed
+4 horse-power, with a consumption of 5.3 pounds<span class='pagenum'><a name="Page_327" id="Page_327">[327]</a></span>
+of coal per hour. This is a good result for so small an
+amount of work, and for an engine working at so low a
+speed of piston. An engine of 30 horse-power, also working
+very slowly, required but 4.1 pounds of coal per hour
+per horse-power.</p>
+
+<p>The work of Perkins and of Alban, like that of their
+predecessors, Evans, Stevens, and Trevithick, was, however,
+the work of engineers who were far ahead of their time.
+The general practice, up to the time which marked the
+beginning of the modern &#8220;period of refinement,&#8221; had been
+but gradually approximating that just described. Higher
+pressures were slowly approached; higher piston-speeds
+came slowly into use; greater expansion was gradually
+adopted; the causes of losses of heat were finally discovered,
+and steam-jacketing and external non-conducting coverings
+were more and more generally applied as builders
+became more familiar with their work. The &#8220;compound
+engine&#8221; was now and then adopted; and each experiment,
+made with higher steam and greater expansion, was more
+nearly successful than the last.</p>
+
+<p>Finally, all these methods of securing economy became
+recognized, and the reasons for their adoption became
+known. It then remained, as the final step in this progression,
+to combine all these requisites of economical working
+in a double-cylinder engine, steam-jacketed, well protected
+by non-conducting coverings, working steam of high pressure,
+and with considerable expansion at high piston-speed.
+This is now done by the best builders.</p>
+
+<p>One of the best examples of this type of engine is that
+constructed by the sons of Jacob Perkins, who continued
+the work of their father after his death. Their engines are
+single-acting, and the small or high-pressure cylinder is
+placed on the top of the larger or low-pressure cylinder.
+The valves are worked by rotating stems, and the loss of
+heat and burning of packing incident to the use of the common
+method are thus avoided. The stuffing-boxes are<span class='pagenum'><a name="Page_328" id="Page_328">[328]</a></span>
+placed at the end of long sleeves, closely surrounding the
+vertical valve-stems also, and the water of condensation
+which collects in these sleeves is an additional and thorough
+protection against excessively high temperature at the packing.
+The piston-rings are made of the alloy which has been
+found to require no lubrication.</p>
+
+<p>Steam is usually worked at from 250 to 450 pounds, and
+is generated in boilers composed of small tubes three inches
+in diameter and three-eighths of an inch thick, which are
+tested under a pressure of 2,500 pounds per square inch.
+The safety-valve is usually loaded to 400 pounds. The
+boiler is fed with distilled water, obtained principally by
+condensation of the exhaust-steam, any deficiency being
+made up by the addition of water from a distilling apparatus.
+Under these conditions, but 1<span class="enum">1</span>&#8725;<span class="denom">4</span> pound of coal is
+consumed per hour and per horse-power.</p>
+
+<p><span class="smcap">The Pumping-Engine</span> in use at the present time has
+passed through a series of changes not differing much from
+that which has been traced with the stationary mill-engine.
+The Cornish engine is still used to some extent for supplying
+water to towns, and is retained at deep mines. The
+modern Cornish engine differs very little from that of the
+time of Watt, except in the proportions of parts and the
+form of its details. Steam-pressures are carried which were
+never reached during the preceding period, and, by careful
+adjustment of well-set and well-proportioned valves and
+gearing, the engine has been made to work rather more rapidly,
+and to do considerably more work. It still remains,
+however, a large, costly, and awkward contrivance, requiring
+expensive foundations, and demanding exceptional care,
+skill, and experience in management. It is gradually going
+out of use. This engine, as now constructed by good
+builders, is shown in section in <a href="#Fig101">Fig. 101</a>.</p>
+
+<p>A comparison with the Watt engine of a century earlier
+will at once enable any one to appreciate the extent to
+which changes may be made in perfecting a machine, even<span class='pagenum'><a name="Page_329" id="Page_329">[329]</a></span>
+after it has become complete, so far as supplying it with
+all essential parts can complete it.</p>
+
+<div class="figcenter"><a name="Fig101" id="Fig101"></a>
+<img src="images/illo356.png" alt="Cornish Pumping-Engine" width="400" height="447" />
+<p class="caption"><span class="smcap">Fig. 101.</span>&mdash;Cornish Pumping-Engine, 1880.</p></div>
+
+<p>In the figure, <i>A</i> is the cylinder, taking steam from the
+boiler through the steam-passage, <i>M</i>. The steam is first
+admitted above the piston, <i>B</i>, driving it rapidly downward
+and raising the pump-rod, <i>E</i>. At an early period in the
+stroke the admission of steam is checked by the sudden
+closing of the induction-valve at <i>M</i>, and the stroke is completed
+under the action of expanding steam assisted by the
+inertia of the heavy parts already in motion. The necessary
+weight and inertia is afforded, in many cases, where
+the engine is applied to the pumping of deep mines, by the<span class='pagenum'><a name="Page_330" id="Page_330">[330]</a></span>
+immensely long and heavy pump-rods. Where this weight
+is too great, it is counterbalanced, and where too small,
+weights are added. When the stroke is completed, the
+&#8220;equilibrium valve&#8221; is opened, and the steam passes from
+above to the space below the piston, and an equilibrium of
+pressure being thus produced, the pump-rods descend, forcing
+the water from the pumps and raising the steam-piston.
+The absence of the crank, or other device which might determine
+absolutely the length of stroke, compels a very
+careful adjustment of steam-admission to the amount of
+load. Should the stroke be allowed to exceed the proper
+length, and should danger thus arise of the piston striking
+the cylinder-head, <i>N</i>, the movement is checked by buffer-beams.
+The valve-motion is actuated by a plug-rod, <i>J K</i>,
+as in Watt&#8217;s engine. The regulation is effected by a &#8220;cataract,&#8221;
+a kind of hydraulic governor, consisting of a plunger-pump,
+with a reservoir attached. The plunger is raised by
+the engine, and then automatically detached. It falls with
+greater or less rapidity, its velocity being determined by
+the size of the eduction-orifice, which is adjustable by hand.
+When the plunger reaches the bottom of the pump-barrel,
+it disengages a catch, a weight is allowed to act upon the
+steam-valve, opening it, and the engine is caused to make a
+stroke. When the outlet of the cataract is nearly closed,
+the engine stands still a considerable time while the plunger
+is descending, and the strokes succeed each other at long
+intervals. When the opening is greater, the cataract acts
+more rapidly, and the engine works faster. This has been
+regarded until recently as the most economical of pumping-engines,
+and it is still generally used in freeing mines of
+water, and in situations where existing heavy pump-rods
+may be utilized in counterbalancing the steam-pressure,
+and, by their inertia, in continuing the motion after the
+steam, by its expansion, has become greatly reduced in
+pressure.</p>
+
+<p>In this engine a gracefully-shaped and strong beam, <i>D</i>,<span class='pagenum'><a name="Page_331" id="Page_331">[331]</a></span>
+has taken the place of the ruder beam of the earlier period,
+and is carried on a well-built wall of masonry, <i>R</i>. <i>F</i> is the
+exhaust-valve, by which the steam passes to the condenser,
+<i>G</i>, beside which is the air-pump, <i>H</i>, and the hot-well, <i>I</i>.
+The cylinder is steam-jacketed, <i>P</i>, and protected against
+losses of heat by radiation by a brick wall, <i>O</i>, the whole
+resting on a heavy foundation, <i>Q</i>.</p>
+
+<p>The Bull Cornish engine is also still not infrequently
+seen in use. The Cornish engine of Great Britain averages
+a duty of about 45,000,000 pounds raised one foot high per
+100 pounds of coal. More than double this economy has
+sometimes been attained.</p>
+
+<div class="figcenter"><a name="Fig102" id="Fig102"></a>
+<img src="images/illo358.png" alt="Steam Pump" width="400" height="297" />
+<p class="caption"><span class="smcap">Fig. 102.</span>&mdash;Steam-Pump.</p></div>
+
+<p>A vastly simpler form of pumping-engine without fly-wheel
+is the now common &#8220;direct-acting steam-pump.&#8221;
+This engine is generally made use of in feeding steam-boilers,
+as a forcing and fire pump, and wherever the<span class='pagenum'><a name="Page_332" id="Page_332">[332]</a></span>
+amount of water to be moved is not large, and where the
+pressure is comparatively great. The steam-cylinder, <i>A R</i>,
+and feed-pump, <i>B Q</i> (<a href="#Fig102">Fig. 102</a>), are in line, and the two
+pistons have usually one rod, <i>D</i>, in common. The two cylinders
+are connected by a strong frame, <i>N</i>, and two standards
+fitted with lugs carry the whole, and serve as a means
+of bolting the pump to the floor or to its foundation.</p>
+
+<p>The method of working the steam-valve of the modern
+steam-pump is ingenious and peculiar. As shown, the pistons
+are moving toward the left; when they reach the end
+of their stroke, the face of the piston strikes a pin or other
+contrivance, and thus moves a small auxiliary valve, <i>I</i>,
+which opens a port, <i>E</i>, and causes steam to be admitted behind
+a piston, or permits steam to be exhausted, as in the
+figure, from before the auxiliary piston, <i>F</i>, and the pressure
+within the main steam-chest then forces that piston over,
+moving the main steam-valve, <i>G</i>, to which it is attached,
+admitting steam to the left-hand side of the main piston,
+and exhausting on the right-hand side, <i>A</i>. Thus the motion
+of the engine operates its own valves in such a manner
+that it is never liable to stop working at the end of the stroke,
+notwithstanding the absence of the crank and fly-wheel, or
+of independent mechanism, like the cataract of the Cornish
+engine. There is a very considerable variety of pumps of
+this class, all differing in detail, but all presenting the distinguishing
+feature of auxiliary valve and piston, and a
+connection by which it and the main engine each works the
+valve of the other combination.</p>
+
+<div class="figcenter"><a name="Fig103" id="Fig103"></a>
+<img src="images/illo360.png" alt="Section Worthinton Pumping-Engine" width="547" height="390" />
+<p class="caption"><span class="smcap">Fig. 103.</span>&mdash;The Worthington Pumping-Engine, 1876. Section.</p></div>
+
+<p>In some cases these pumps are made of considerable
+size, and are applied to the elevation of water in situations
+to which the Cornish engine was formerly considered exclusively
+applicable. The accompanying <a href="#Fig103">figure</a> illustrates such
+a pumping-engine, as built for supplying cities with water.
+This is a &#8220;compound&#8221; direct-acting pumping-engine. The
+cylinders, <i>A B</i>, are placed in line, working one pump, <i>F</i>,
+and operating their own air-pumps, <i>D D</i>, by a bell-crank<span class='pagenum'><a name="Page_333" id="Page_333">[333]</a></span>
+lever, <i>L H</i>, connected to the pump-buckets by links, <i>I K</i>.
+Steam exhausted from the small cylinder, <i>A</i>, is further expanded
+in the large cylinder, <i>B</i>, and thence goes to the
+condenser, <i>C</i>. The valves, <i>N M</i>, are moved by the valve-gear,
+<i>L</i>, which is actuated by the piston-rod of a similar
+pair of cylinders placed by the side of the first. These<span class='pagenum'><a name="Page_334" id="Page_334">[334]</a></span>
+valves are balanced, and the balance-plates, <i>R Q</i>, are suspended
+from the rods, <i>O P</i>, which allow them to move with
+the valves. By connecting the valves of each engine with<span class='pagenum'><a name="Page_335" id="Page_335">[335]</a></span>
+the piston-rod of the other, it is seen that the two engines
+must work alternately, the one making a stroke while the
+other is still, and then itself stopping a moment while the
+latter makes its stroke.</p>
+
+<p>Water enters the pump through the induction-pipe, <i>E</i>,
+passes into the pump-barrel through the valves, <i>V V</i>, and
+issues through the eduction-valves, <i>T T</i>, and goes on to the
+&#8220;mains&#8221; by the pipe, <i>G</i>, above which is seen an air-chamber,
+which assists to preserve a uniform pressure on that
+side the pump. This engine works very smoothly and
+quietly, is cheap and durable, and has done excellent duty.</p>
+
+<div class="figcenter"><a name="Fig104" id="Fig104"></a>
+<img src="images/illo361.png" alt="Worthington Pumping-Engine" width="575" height="343" />
+<p class="caption"><span class="smcap">Fig. 104.</span>&mdash;The Worthington Pumping-Engine.</p>
+<p class="center fsize80"><a href="images/large361.png">Large scale image</a> (362 kB).</p></div>
+
+<p>Beam pumping-engines are now almost invariably built
+with crank and fly-wheel, and very frequently are compound
+engines. The accompanying <a href="#Fig105">illustration</a> represents
+an engine of the latter form.</p>
+
+<div class="figcenter"><a name="Fig105" id="Fig105"></a>
+<img src="images/illo362.png" alt="Double-Cylinder Pumping-Engine" width="460" height="350" />
+<p class="caption"><span class="smcap">Fig. 105.</span>&mdash;Double-Cylinder Pumping-Engine, 1878.</p></div>
+
+<p><i>A</i> and <i>B</i> are the two steam-cylinders, connected by
+links and parallel motion, <i>C D</i>, to the great cast-iron beam,
+<i>E F</i>. At the opposite end of the beam, the connecting-rod,<span class='pagenum'><a name="Page_336" id="Page_336">[336]</a></span>
+<i>G</i>, turns a crank, <i>H</i>, and fly-wheel, <i>L M</i>, which regulates
+the motion of the engine and controls the length of
+stroke, averting all danger of accident occurring in consequence
+of the piston striking either cylinder-head. The
+beam is carried on handsomely-shaped iron columns, which,
+with cylinders, pump, and fly-wheel, are supported by a<span class='pagenum'><a name="Page_337" id="Page_337">[337]</a></span>
+substantial stone foundation. The pump-rod, <i>I</i>, works a
+double-acting pump, <i>J</i>, and the resistance to the issuing
+water is rendered uniform by an air-chamber, <i>K</i>, within
+which the water rises and falls when pressures tend to vary
+greatly. A revolving shaft, <i>N</i>, driven from the fly-wheel
+shaft, carries cams, <i>O P</i>, which move the lifting-rods seen
+directly over them and the valves which they actuate. Between
+the steam-cylinders and the columns which carry the
+beams is a well, in which are placed the condenser and air-pump.
+Steam is carried at 60 or 80 pounds pressure, and
+expanded from 6 to 10 times.</p>
+
+<div class="figcenter"><a name="Fig106" id="Fig106"></a>
+<img src="images/illo363.png" alt="Lawrence Water Works Engine" width="332" height="450" />
+<p class="caption"><span class="smcap">Fig. 106.</span>&mdash;The Lawrence Water-Works Engine.</p></div>
+
+<div class="figcenter"><a name="Fig107" id="Fig107">
+</a><img src="images/illo364.png" alt="Leavitt Pumping-Engine" width="350" height="413" />
+<p class="caption"><span class="smcap">Fig. 107.</span>&mdash;The Leavitt Pumping-Engine.</p></div>
+
+<p>A later form of double-cylinder beam pumping-engine
+is that invented and designed by E. D. Leavitt, Jr., for the
+Lawrence Water-Works, and shown in <a href="#Fig106">Figs. 106</a> and <a href="#Fig107">107</a>.
+The two cylinders are placed one on each side the centre of
+the beam, and are so inclined that they may be coupled to<span class='pagenum'><a name="Page_338" id="Page_338">[338]</a></span>
+opposite ends of it, while their lower ends are placed close
+together. At their upper ends a valve is placed at each
+end of the connecting steam-pipe. At their lower ends a
+single valve serves as exhaust-valve to the high-pressure
+and as steam-valve to the low-pressure cylinder. The pistons
+move in opposite directions, and steam is exhausted
+from the high-pressure cylinder directly into the nearer end
+of the low-pressure cylinder. The pump, of the &#8220;Thames-Ditton&#8221;
+or &#8220;bucket-and-plunger&#8221; variety, takes a full supply
+of water on the down-stroke, and discharges half when
+rising and half when descending again. The duty of this
+engine is reported by a board of engineers as 103,923,215
+foot-pounds for every 100 pounds of coal burned. The
+duty of a moderately good engine is usually considered to
+be from 60 to 70 millions. This engine has steam-cylinders
+of 17<span class="enum">1</span>&#8725;<span class="denom">2</span> and 36 inches diameter respectively, with a stroke of
+7 feet. The pump had a capacity of about 195 gallons,
+and delivered 96 per cent. Steam was carried at a pressure
+of 75 pounds above the atmosphere, and was expanded
+about 10 times. Plain horizontal tubular boilers were used,
+evaporating 8.58 pounds of water from 98&deg; Fahr. per pound
+of coal.</p>
+
+<p><span class="smcap">Steam-boilers.</span>&mdash;The steam supplied to the forms of
+stationary engine which have been described is generated in
+steam-boilers of exceedingly varied forms. The type used
+is determined by the extent to which their cost is increased
+in the endeavor to economize fuel by the pressure of steam
+carried, by the greater or less necessity of providing against
+risk of explosion, by the character of the feed-water to be
+used, by the facilities which may exist for keeping in good
+repair, and even by the character of the men in whose
+hands the apparatus is likely to be placed.</p>
+
+<p>As has been seen, the changes which have marked the
+growth and development of the steam-engine have been
+accompanied by equally marked changes in the forms of
+the steam-boiler. At first, the same vessel served the distinct<span class='pagenum'><a name="Page_339" id="Page_339">[339]</a></span>
+purposes of steam-generator and steam-engine. Later,
+it became separated from the engine, and was then specially
+fitted to perform its own peculiar functions; and its form
+went through a series of modifications under the action of
+the causes already stated.</p>
+
+<p>When steam began to be usefully applied, and considerable
+pressures became necessary, the forms given to boilers
+were approximately spherical, ellipsoidal, or cylindrical.
+Thus the boilers of De Caus (1615) and of the Marquis of
+Worcester (1663) were spherical and cylindrical; those of
+Savery (1698) were ellipsoidal and cylindrical. After the
+invention of the steam-engine of Newcomen, the pressures
+adopted were again very low, and steam-boilers were given
+irregular forms until, at the beginning of the present century,
+they were again of necessity given stronger shapes.
+The material was at first frequently copper; it is now usually
+wrought-iron, and sometimes steel.</p>
+
+<p>The present forms of steam-boilers may be classified as
+plain, flue, and tubular boilers. The plain cylindrical or
+common cylinder boiler is the only representative of the first
+class in common use. It is perfectly cylindrical, with heads
+either flat or hemispherical. There is usually attached
+to the boiler a &#8220;steam-drum&#8221; (a small cylindrical vessel),
+from which the steam is taken by the steam-pipe. This enlargement
+of the steam-space permits the mist, held in suspension
+by the steam when it first rises from the surface of
+the water, to separate more or less completely before the
+steam is taken from the boiler.</p>
+
+<div class="figcenter"><a name="Fig108" id="Fig108"></a>
+<img src="images/illo368.png" alt="Babcock &amp; Wilcox's Vertical Boiler" width="350" height="537" />
+<p class="caption"><span class="smcap">Fig. 108.</span>&mdash;Babcock &amp; Wilcox&#8217;s Vertical Boiler.</p></div>
+
+<p>Flue-boilers are frequently cylindrical, and contain one
+or more cylindrical flues, which pass through from end to
+end, beneath the water-line, conducting the furnace-gases,
+and affording a greater area of heating-surface than can be
+obtained in the plain boiler. They are usually from 30 to
+48 inches in diameter, and one foot or less in length for
+each inch of diameter. Some are, however, made 100 feet
+and more in length. The boiler is made of iron
+<span class="enum">1</span>&#8725;<span class="denom">4</span>
+to <span class="enum">3</span>&#8725;<span class="denom">8</span>
+of an<span class='pagenum'><a name="Page_340" id="Page_340">[340]</a></span>
+inch in thickness, with hemispherical or carefully stayed
+flat heads, and without flues. The whole is placed in a
+brickwork setting. These boilers are used where fuel is
+inexpensive, where the cost of repairing would be great, or
+where the feed-water is impure. A cylindrical boiler, having
+one flue traversing it longitudinally, is called a Cornish
+boiler, as it is generally supposed to have been first used in
+Cornwall. It was probably first invented by Oliver Evans
+in the United States, previous to 1786, at which time he
+had it in use. The flue has usually a diameter 0.5 or 0.6
+the diameter of the boiler. A boiler containing two longitudinal
+flues is called the Lancashire boiler. This form
+was also introduced by Oliver Evans. The flues have one-third
+the diameter of the boiler. Several flues of smaller
+diameter are often used, and when a still greater proportional
+area of heating-surface is required, tubes of from 1<span class="enum">1</span>&#8725;<span class="denom">4</span>
+inch to 4 or 5 inches in diameter are substituted for flues.
+The flues are usually constructed by riveting sheets together,
+as in making the shell or outer portion. They are
+sometimes welded by British manufacturers, but rarely if
+ever in the United States. Tubes are always &#8220;lap-welded&#8221;
+in the process of rolling them. Small tubes were first used
+in the United States, about 1785. In portable, locomotive,
+and marine steam-boilers, the fire must be built within the
+boiler itself, instead of (as in the above described stationary
+boilers) in a furnace of brickwork exterior to the boiler.
+The flame and gases from the furnace or fire-box in these
+kinds of boiler are never led through brick passages en
+route to the chimney, as often in the preceding case, but
+are invariably conducted through flues or tubes, or both, to
+the smoke-stack. These boilers are also sometimes used as
+stationary boilers. <a href="#Fig108">Fig. 108</a> represents such a steam-boiler
+in section, as it is usually exhibited in working drawings.
+Provision is made to secure a good circulation of water in
+these boilers by means of the &#8220;baffle-plates,&#8221; seen in the
+sketch, which compel the water to flow as indicated by the<span class='pagenum'><a name="Page_341" id="Page_341">[341]</a></span>
+arrows. The tubes are frequently made of brass or of copper,
+to secure rapid transmission of heat to the water, and
+thus to permit the use of a smaller area of heating-surface
+and a smaller boiler. The steam-space is made as large as
+possible, to secure immunity from &#8220;priming&#8221; or the &#8220;entrainment&#8221;
+of water with the steam. This type of steam-boiler,
+invented by Nathan Read, of Salem, Mass., in 1791,
+and patented in April of that year, was the earliest of the
+tubular boilers. In the locomotive boiler (<a href="#Fig109">Fig. 109</a>), as in
+the preceding, the characteristics are a fire-box at one end
+of the shell and a set of tubes through which the gases pass<span class='pagenum'><a name="Page_342" id="Page_342">[342]</a></span>
+directly to the smoke-stack. Strength, compactness, great
+steaming capacity, fair economy, moderate cost, and convenience
+of combination with the running parts, are secured
+by the adoption of this form. It is frequently used also
+for portable and stationary engines. It was invented in
+France by M. Seguin, and in England by Booth, and used
+by George Stephenson at about the same time&mdash;1828 or
+1829.</p>
+
+<div class="figcenter"><a name="Fig109" id="Fig109"></a>
+<img src="images/illo369.png" alt="Stationary 'Locomotive' Boiler" width="498" height="350" />
+<p class="caption"><span class="smcap">Fig. 109.</span>&mdash;Stationary &#8220;Locomotive&#8221; Boiler.</p></div>
+
+<p>Since the efficiency of a steam-boiler depends upon the
+extent of effective heating-surface per unit of weight of
+fuel burned in any given time&mdash;or, ordinarily, upon the
+ratio of the areas of heating and grate surface&mdash;peculiar
+expedients are sometimes adopted, having for their object
+the increase of heating-surface, without change of form of
+boiler and without proportionate increase of cost.</p>
+
+<div class="figright"><a name="Fig110" id="Fig110">
+</a><img src="images/illo370.png" alt="Galloway Conical Tube" width="300" height="153" />
+<p class="caption"><span class="smcap">Fig. 110.</span></p></div>
+
+<p>One of these methods is that of the use of Galloway
+conical tubes (<a href="#Fig110">Fig. 110</a>). These are very largely
+used in<span class='pagenum'><a name="Page_343" id="Page_343">[343]</a></span>
+Great Britain, but are seldom if ever seen in the United
+States. The Cornish boiler, to which they are usually applied,
+consists of a large cylindrical shell, 6 feet or more in
+diameter, containing one tube of
+about one-half as great dimensions,
+or sometimes two of one-third
+the diameter of the shell
+each. Such boilers have a very
+small ratio of heating to grate
+surface, and their large tubes are
+peculiarly liable to collapse. To remove these objections,
+the Messrs. Galloway introduced stay-tubes into the flues,
+which tubes are conical in form, and are set in either a vertical
+or an inclined position, the larger end uppermost.
+The area of heating-surface is thus greatly increased, and,
+at the same time, the liability to collapse is reduced. The
+same results are obtained by another device of Galloway,
+which is sometimes combined with that just described in
+the same boiler. Several sheets in the flue have &#8220;pockets&#8221;
+worked into them, which pockets project into the flue-passage.</p>
+
+<p>Another device is that of an American engineer, Miller,
+who surrounds the furnace of cylindrical and other boilers
+with water-tubes. The &#8220;fuel-economizers&#8221; of Greene and
+others consist of similar collections of tubes set in the flues,
+between the boiler and the chimney.</p>
+
+<p>&#8220;<i>Sectional</i>&#8221; boilers are gradually coming into use with
+high pressures, on account of their greater safety against
+disastrous explosions. The earliest practicable example of
+a boiler of this class was probably that of Colonel John Stevens,
+of Hoboken, N. J. Dr. Alban, who, forty years later,
+attempted to bring this type into general use, and constructed
+a number of such boilers, did not succeed. Their
+introduction, like that of all radical changes in engineering,
+has been but slow, and it has been only recently that their
+manufacture has become an important branch of industry.<span class='pagenum'><a name="Page_344" id="Page_344">[344]</a></span></p>
+
+<p>A committee of the American Institute, of which the
+author was chairman, in 1871, examined several boilers of
+this and the ordinary type, and tested them very carefully.
+They reported that they felt &#8220;confident that the introduction
+of this class of steam-boilers will do much toward the
+removal of the cause of that universal feeling of distrust
+which renders the presence of a steam-boiler so objectionable
+in every locality. The difficulties in thoroughly inspecting
+these boilers, in regulating their action, and other
+faults of the class, are gradually being overcome, and the
+committee look forward with confidence to the time when
+their use will become general, to the exclusion of older and
+more dangerous forms of steam-boilers.&#8221;</p>
+
+<p>The economical performance of these boilers with a similar
+ratio of heating to grate surface is equal to that of
+other kinds. In fact, they are usually given a somewhat
+higher ratio, and their economy of fuel frequently exceeds
+that of the other types. Their principal defect is their
+small capacity for steam and water, which makes it extremely
+difficult to obtain steady steam-pressure. Where
+they are employed, the feed and draught should be, if possible,
+controlled by automatic attachments, and the feed-water
+heated to the highest attainable temperature. Their
+satisfactory working depends, more than in other cases, on
+the ability of the fireman, and can only be secured by the
+exercise of both care and skill.</p>
+
+<p>Many forms of these boilers have been devised. Walter
+Hancock constructed boilers for his steam-carriage of
+flat plates connected by stay-bolts, several such sections
+composing the boiler; and about the same time (1828) Sir
+Goldsworthy Gurney constructed for a similar purpose boilers
+consisting of a steam and a water reservoir, placed one
+above the other, and connected by triangularly-bent water-tubes
+exposed to the heat of the furnace-gases. Jacob Perkins
+made many experiments looking to the employment of
+very high steam-pressures, and in 1831 patented a boiler of<span class='pagenum'><a name="Page_345" id="Page_345">[345]</a></span>
+this class, in which the heating-surfaces nearest the fire were
+composed of iron tubes, which tubes also served as grate-bars.
+The steam and water space was principally comprised
+within a comparatively large chamber, of which the
+walls were secured by closely distributed stay-bolts. For
+extremely high pressures, boilers composed only of tubes
+were used. Dr. Ernst Alban described the boiler already
+referred to, and its construction and operation, and stated
+that he had experimented with pressures as high as 1,000
+pounds to the square inch.</p>
+
+<div class="figcenter"><a name="Fig111" id="Fig111"></a>
+<img src="images/illo372.png" alt="Harrison's Sectional Boiler" width="385" height="350" />
+<p class="caption"><span class="smcap">Fig. 111.</span>&mdash;Harrison&#8217;s Sectional Boiler.</p></div>
+
+<p>The Harrison steam-boiler, which has been many years
+in use in the United States, consists of several sections, each
+of which is made up of hollow globes of cast-iron, communicating
+with each other by necks cast upon the spheres,
+and fitted together with faced joints. Long bolts, extending
+from end to end of each row, bind the spheres together.
+(<i>See</i> <a href="#Fig111">Fig. 111</a>.)</p>
+
+<div class="figcenter"><a name="Fig112" id="Fig112"></a>
+<img src="images/illo373.png" alt="Babcock &amp; Wilcock's Sectionasl Boiler" width="450" height="286" />
+<p class="caption"><span class="smcap">Fig. 112.</span>&mdash;Babcock and Wilcox&#8217;s Sectional Boiler.</p></div>
+
+<p>An example of another modern type in extensive use is
+given in <a href="#Fig112">Fig. 112</a>, a semi-sectional boiler, which consists of
+a series of inclined wrought-iron tubes, connected by T-heads,<span class='pagenum'><a name="Page_346" id="Page_346">[346]</a></span>
+which form the vertical water-channels, at each end.
+The joints are faced by milling them, and then ground so
+perfectly tight that a pressure of 500 pounds to the square
+inch is insufficient to produce leakage. No packing is used.
+The fire is made under the front and higher end of the
+tubes, and the products of combustion pass up between the
+tubes into a combustion-chamber under the steam and water
+drum; hence they pass down between the tubes, then once
+more up through the space between the tubes, and off to
+the chimney. The steam is taken out at the top of the
+steam-drum near the back end of the boiler. The rapid
+circulation prevents to some extent the formation of deposits
+or incrustations upon the heating-surfaces, sweeping
+them away and depositing them in the mud-drum, whence
+they are blown out. Rapid circulation of water, as has
+been shown by Prof. Trowbridge, also assists in the extraction
+of the heat from the gases, by the presentation
+of fresh water continually, as well as by the prevention of
+incrustation.</p>
+
+<div class="figcenter"><a name="Fig113" id="Fig113"></a>
+<img src="images/illo374.png" alt="Root Sectional Boiler" width="350" height="389" />
+<p class="caption"><span class="smcap">Fig. 113.</span>&mdash;Root Sectional Boiler.</p></div>
+
+<p><span class='pagenum'><a name="Page_347" id="Page_347">[347]</a></span>Attempts have been made to adapt sectional boilers to
+marine engines; but very little progress has yet been made
+in their introduction. The Root sectional boiler (<a href="#Fig113">Fig. 113</a>),
+an American design, which is in extensive use in the United
+States and Europe, has also been experimentally placed in
+service on shipboard. Its heating-surface consists wholly
+of tubes, which are connected by a peculiarly formed
+series of caps; the joints are made tight with rubber
+&#8220;grummets.&#8221;</p>
+
+
+<hr class="c05" />
+<h4><span class="smcap">Section II.&mdash;Portable and Locomotive Engines.</span></h4>
+<hr class="c05" />
+
+<p>Engines and boilers, when of small size, are now often
+combined in one structure which may be readily transported.
+Where they have a common base-plate simply, as in
+<a href="#Fig114">Fig. 114</a>, they are called, usually, &#8220;semi-portable engines.&#8221;
+These little engines have some decided advantages. Being
+attached to one base, the combined engine and boiler is<span class='pagenum'><a name="Page_348" id="Page_348">[348]</a></span>
+easily transported, occupies little space, and may very
+readily be mounted upon wheels, rendering it peculiarly
+well adapted for agricultural purposes.</p>
+
+<div class="figcenter"><a name="Fig114" id="Fig114"></a>
+<img src="images/illo375.png" alt="Semi-Portable Engine" width="350" height="431" />
+<p class="caption"><span class="smcap">Fig. 114.</span>&mdash;Semi-Portable Engine, 1878.</p></div>
+
+<p>The example here shown differs in its design from those
+usually seen in the market. The engine is not fastened to
+or upon the boiler, and is therefore not affected by expansion,
+nor are the bearings overheated by conduction or by
+ascending heat from the boiler. The fly-wheel is at the
+base, which arrangement secures steadiness at the high
+speed which is a requisite for economy of fuel. The boilers
+are of the upright tubular style, with internal fire-box,<span class='pagenum'><a name="Page_349" id="Page_349">[349]</a></span>
+and are intended to be worked at 150 pounds pressure per
+inch. They are fitted with a baffle-plate and circulating-pipe,
+to prevent priming, and also with a fusible plug, which will
+melt and prevent the crown-sheet of the boiler burning, if
+the water gets low.</p>
+
+<p>Another illustration of this form of engine, as built in
+small sizes, is seen <a href="#Fig115">below</a>. The peculiarity of this engine
+is, that the cylinder is placed in the top of the boiler, which
+is upright. By this arrangement the engine is constantly
+drawing from the boiler the hottest and driest steam, and
+there is thus no liability of serious loss by condensation,
+which is rapid, even in a short pipe, when the engine is
+separate from the boiler.</p>
+
+<div class="figcenter"><a name="Fig115" id="Fig115"></a>
+<img src="images/illo376.png" alt="Semi-Portable Engine" width="208" height="350" />
+<p class="caption"><span class="smcap">Fig. 115.</span>&mdash;Semi-Portable Engine, 1878.</p></div>
+
+<p>The engine illustrated is rated at 10 horse-power, and
+makers are always expected to guarantee their machines to<span class='pagenum'><a name="Page_350" id="Page_350">[350]</a></span>
+work up to the rated power. The cylinder is 7 by 7 inches,
+and the main shaft is directly over it. On this shaft are
+three eccentrics, one working the pump, one moving the
+valves, and the third one operating the cut-off. The driving-pulley
+is 20 inches in diameter, and the balance-wheel
+30 inches. The boiler has 15 1<span class="enum">1</span>&#8725;<span class="denom">4</span>-inch flues. It is furnished
+with a heater in its lower portion. The boiler of this engine
+is tested up to 200 pounds, and is calculated to carry
+100 pounds working pressure, though that is not necessary
+to develop the full power of the engine. The compactness
+of the whole machine is exceptional. It can be set up in a
+space 5 feet square and 8 feet high. The weight of the 10
+horse-power engine is 1,540 pounds, and of the whole machine
+4,890 pounds, boxed for shipment. Every part of the
+mechanism usually fits and works with the exactness of a
+gun-lock, as each piece is carefully made to gauge.</p>
+
+<p>Portable engines are those which are especially intended
+to be moved conveniently from place to place. The engine
+is usually attached to the boiler, and the feed-pump is generally
+attached to the engine. The whole machine is carried
+on wheels, and is moved from one place to another,
+usually by horses, but sometimes by its own engine, which
+is coupled by an engaging and disengaging apparatus to
+the rear-wheels. English builders have usually excelled in
+the construction of this class of steam-engine, although it is
+probable that the best American engines are fully equal to
+them in design, material, and construction.</p>
+
+<p>The later work of the best-known English builders has
+given economical results that have surprised engineers.
+The annual &#8220;shows&#8221; of the Royal Agricultural Society
+have elicited good evidence of skill in management as well
+as of excellence of design and construction. Some little
+portable engines have exhibited an economical efficiency
+superior to that of the largest marine engines of any but
+the compound type, and even closely competing with that
+form. The causes of this remarkable economy are readily<span class='pagenum'><a name="Page_351" id="Page_351">[351]</a></span>
+learned by an inspection of these engines, and by observation
+of the method of managing them at the test-trial.
+The engines are usually very carefully designed. The cylinders
+are nicely proportioned to their work, and their pistons
+travel at high speed. Their valve-gear consists usually
+of a plain slide-valve, supplemented by a separate expansion-slide,
+driven by an independent eccentric, and capable
+of considerable variation in the point of cut-off. This form
+of expansion-gear is very effective&mdash;almost as much so as a
+drop cut-off&mdash;at the usual grade of expansion, which is not
+far from four times. The governor is usually attached to a
+throttle-valve in the steam-pipe, an arrangement which is
+not the best possible under variable loads, but which produces
+no serious loss of efficiency when the engine is driven,
+as at competitive trials, under the very uniform load of a
+Prony strap-brake and at very nearly the maximum capacity
+of the machine. The most successful engines have had
+steam-jacketed cylinders&mdash;always an essential to maximum
+economy&mdash;with high steam and a considerable expansion.
+The boilers are strongly made, and are, as are also
+all other heated surfaces, carefully clothed with non-conducting
+material, and well lagged over all. The details
+are carefully proportioned, the rods and frames are strong
+and well secured together, and the bearings have large rubbing-surfaces.
+The connecting-rods are long and easy-working,
+and every part is capable of doing its work without
+straining and with the least friction.</p>
+
+<p>In handling the engines at the competitive trial, most
+experienced and skillful drivers are selected. The difference
+between the performances of the same engine in different
+hands has been found to amount to from 10 to 15 per cent.,
+even where the competitors were both considered exceptionally
+skillful men. In manipulating the engine, the fires
+are attended to with the utmost care; coal is thrown upon
+them at regular and frequent intervals, and a uniform depth
+of fuel and a perfectly clean fire are secured. The sides<span class='pagenum'><a name="Page_352" id="Page_352">[352]</a></span>
+and corners of the fire are looked after with especial care.
+The fire-doors are kept open the least possible time; not a
+square inch of grate-surface is left unutilized, and every
+pound of coal gives out its maximum of calorific power, and
+in precisely the place where it is needed. Feed-water is
+supplied as nearly as possible continuously, and with the
+utmost regularity. In some cases the engine-driver stands
+by his engine constantly, feeding the fire with coal in handfuls,
+and supplying the water to the heater by hand by
+means of a cup. Heaters are invariably used in such cases.
+The exhaust is contracted no more than is absolutely necessary
+for draught. The brake is watched carefully, lest
+irregularity of lubrication should cause oscillation of speed
+with the changing resistance. The load is made the maximum
+which the engine is designed to drive with economy.
+Thus all conditions are made as favorable as possible to
+economy, and they are preserved as invariable as the utmost
+care on the part of the attendant can make them.</p>
+
+<p>These trials are usually of only three or five hours&#8217; duration,
+and thus terminate before it becomes necessary to
+clean fires. The following are results obtained at the trial
+of engines which took place in July, 1870, at the Oxford
+Agricultural Fair:</p>
+
+<table class="fsize80" summary="Oxford Agric. Fair Results">
+
+<tr>
+<td rowspan="2" class="center bt br">MAKER&#8217;S NAME AND<br />RESIDENCE</td>
+<td colspan="3" class="center bt br bb smcap">Cylinders.</td>
+<td rowspan="2" class="center bt br padr1 padl1">Stroke.</td>
+<td colspan="2" class="center bt br bb smcap">Horse-Power.</td>
+<td rowspan="2" class="center bt br padr1 padl1">Point of<br />cut off.</td>
+<td colspan="2" rowspan="2" class="center bt br padr1 padl1">Revolutions<br />per minute.</td>
+<td rowspan="2" class="center bt padr1 padl1">Pounds coal<br />per horse-power<br />per hour.</td>
+</tr>
+
+<tr>
+<td class="center padr1 padl1 bt br">Number.</td>
+<td colspan="2" class="center padr1 padl1 bt br">Diameter.</td>
+<td class="center padr1 padl1 bt br">Nominal.</td>
+<td class="center padr1 padl1 bt br">Dynamo-<br />metric.</td>
+</tr>
+
+<tr>
+<td class="bt br">&nbsp;</td>
+<td class="bt br">&nbsp;</td>
+<td colspan="2" class="center bt br">Inches.</td>
+<td class="center bt br">In.</td>
+<td class="bt br">&nbsp;</td>
+<td class="bt br">&nbsp;</td>
+<td class="bt br">&nbsp;</td>
+<td colspan="2" class="bt br">&nbsp;</td>
+<td class="bt">&nbsp;</td>
+</tr>
+
+<tr>
+<td class="left br">Clayton, Shuttleworth &amp; Co., Lincoln</td>
+<td class="center br">1</td>
+<td class="right padl1">7</td>
+<td class="br">&nbsp;</td>
+<td class="center br">12</td>
+<td class="center br">4</td>
+<td class="center br">4.42</td>
+<td class="center br">.....</td>
+<td class="right padr0">121.6</td>
+<td class="left br padl0 padr1">5</td>
+<td class="center">3.73</td>
+</tr>
+
+<tr>
+<td class="left br">Brown &amp; May, Devizes</td>
+<td class="center br">1</td>
+<td class="right">7</td>
+<td class="left br"><span class="enum">3</span>&#8725;<span class="denom">16</span></td>
+<td class="center br">12</td>
+<td class="center br">4</td>
+<td class="center br">4.19</td>
+<td class="center br">11.48</td>
+<td class="right padr0">125.6</td>
+<td class="left br padl0">5</td>
+<td class="center">4.44</td>
+</tr>
+
+<tr>
+<td class="left br bb padr1">Reading Iron-Works Company, Reading</td>
+<td class="center br bb">1</td>
+<td class="right bb">5</td>
+<td class="left br bb"><span class="enum">3</span>&#8725;<span class="denom">4</span></td>
+<td class="center br bb">14</td>
+<td class="center br bb">4</td>
+<td class="center br bb">4.16</td>
+<td class="center br bb">.....</td>
+<td class="right padr0 bb">145.7</td>
+<td class="br bb">&nbsp;</td>
+<td class="center bb">4.65</td>
+</tr>
+
+</table>
+
+<p><span class='pagenum'><a name="Page_353" id="Page_353">[353]</a></span>These were horizontal engines, attached to locomotive
+boilers.</p>
+
+<p>At a similar exhibition held at Bury, in 1867, considerably
+better results even than these were reported, as below,
+from engines of similar size and styles:</p>
+
+<table class="fsize80" summary="Bury Results">
+
+<tr>
+<td rowspan="2" class="center bt br">MAKER&#8217;S NAME AND<br />RESIDENCE</td>
+<td colspan="3" class="center bt br bb smcap">Cylinders.</td>
+<td rowspan="2" class="center bt br padr1 padl1">Stroke.</td>
+<td colspan="2" class="center bt br bb smcap">Horse-Power.</td>
+<td colspan="2" rowspan="2" class="center bt br padr1 padl1">Point of<br />cut off.</td>
+<td rowspan="2" class="center bt br padr1 padl1">Revolutions<br />per minute.</td>
+<td rowspan="2" class="center bt padr1 padl1">Pounds coal<br />per horse-power<br />per hour.</td>
+</tr>
+
+<tr>
+<td class="center padr1 padl1 bt br">Number.</td>
+<td colspan="2" class="center padr1 padl1 bt br">Diameter.</td>
+<td class="center padr1 padl1 bt br">Nominal.</td>
+<td class="center padr1 padl1 bt br">Dynamo-<br />metric.</td>
+</tr>
+
+<tr>
+<td class="bt br">&nbsp;</td>
+<td class="bt br">&nbsp;</td>
+<td colspan="2" class="center bt br">Inches.</td>
+<td class="center bt br">In.</td>
+<td class="bt br">&nbsp;</td>
+<td class="bt br">&nbsp;</td>
+<td colspan="2" class="bt br">&nbsp;</td>
+<td class="bt br">&nbsp;</td>
+<td class="bt">&nbsp;</td>
+</tr>
+
+<tr>
+<td class="left br">Clayton, Shuttleworth &amp; Co., Lincoln.</td>
+<td class="center br">1</td>
+<td class="right">10</td>
+<td class="br">&nbsp;</td>
+<td class="center br">20</td>
+<td class="center br">10</td>
+<td class="center br">11.00</td>
+<td class="right">3.1</td>
+<td class="left padl0 br">0</td>
+<td class="right padr4 br">&nbsp;71.5</td>
+<td class="center">4.13</td>
+</tr>
+
+<tr>
+<td class="left br bb padr1">Reading Iron-Works Company, Reading.</td>
+<td class="center br bb">1</td>
+<td class="right bb">8</td>
+<td class="left br bb"><span class="enum">5</span>&#8725;<span class="denom">8</span></td>
+<td class="center br bb">20</td>
+<td class="center br bb">10</td>
+<td class="center br bb">10.43</td>
+<td class="right bb">1.4</td>
+<td class="br bb">&nbsp;</td>
+<td class="right padr4 br bb">109.4</td>
+<td class="center bb">4.22</td>
+</tr>
+
+</table>
+
+<p>With all these engines steam-jackets were used; the
+feed-water was highly and uniformly heated by exhaust-steam;
+the coal was selected, finely broken, and thrown on
+the fire with the greatest care; the velocity of the engines,
+the steam-pressure, and the amount of feed-water,
+were very carefully regulated, and all bearings were run
+quite loose; the engine-drivers were usually expert &#8220;jockeys.&#8221;</p>
+
+<p>The next <a href="#Fig116">illustration</a> represents the portable steam-engine
+as built by one of the oldest and most experienced
+manufacturers of such engines in the United States.</p>
+
+<div class="figcenter"><a name="Fig116" id="Fig116"></a>
+<img src="images/illo381.png" alt="Portable Steam-Engine" width="459" height="350" />
+<p class="caption"><span class="smcap">Fig. 116.</span>&mdash;The Portable Steam-Engine, 1878.</p></div>
+
+<p>In the boilers of these engines the heating-surface is
+given less extent than in the stationary engine-boiler, but
+much greater than in the locomotive, and varies from 10 to
+20 square feet per horse-power. The boilers are made very
+strong, to enable them to withstand the strains due to the
+attached engine, which are estimated as equivalent to from
+one-tenth to one-fifth that due to the steam-pressure. The<span class='pagenum'><a name="Page_354" id="Page_354">[354]</a></span>
+boiler is sometimes given even double the strength usual
+with stationary boilers of similar capacity. The engine is
+mounted, in this example, directly over the boiler, and all
+parts are in sight and readily accessible to the engineer.</p>
+
+<p>One of these engines, of 20 horse-power, has a steam-cylinder
+10 inches in diameter and 18 inches stroke of piston,<span class='pagenum'><a name="Page_355" id="Page_355">[355]</a></span>
+making 125 revolutions per minute, and has 9 square
+feet of grate-surface and 288 feet of heating-surface. It
+weighs about 4<span class="enum">1</span>&#8725;<span class="denom">2</span> tons. Steam is carried at 125 pounds.</p>
+
+<p>In the class of engines just described, the draught is
+obtained by the blast of the exhaust-steam which is led
+into the chimney. Such engines are now sold at from $120
+to $150 per horse-power, according to size and quality, the
+smaller engines costing most. The usual consumption of
+fuel is from 4 to 6 pounds per hour and per horse-power,
+burning from 15 to 20 pounds on each square foot of grate,
+and each pound evaporating about 8 pounds of water. A
+usual weight is, for the larger sizes, 500 pounds per horse-power.</p>
+
+<div class="figcenter"><a name="Fig117" id="Fig117"></a>
+<img src="images/illo382.png" alt="Thrashers' Road Engine" width="448" height="350" />
+<p class="caption"><span class="smcap">Fig. 117.</span>&mdash;The Thrashers&#8217; Road-Engine, 1878.</p></div>
+
+<p>These engines are sometimes arranged to propel themselves,<span class='pagenum'><a name="Page_356" id="Page_356">[356]</a></span>
+as in the Mills &#8220;Thrashers&#8217;&#8221; road-engine or locomotive,
+of which the accompanying <a href="#Fig117">engraving</a> is a good representation.
+This engine is proportioned for hauling a tank
+containing 10 barrels, or more, of water and a grain-separator
+over all ordinary roads, and to drive a thrashing-machine
+or saw-mill, developing 20 or 25 horse-power. This
+example of the road-engine has a boiler built to work at
+250 pounds of steam; the engine is designed for a maximum
+power of 30 horses.</p>
+
+<p>This engine has a balanced valve and automatic cut-off,
+and is fitted with a reversing-gear for use on the road.
+The driving-wheels are of wrought-iron, 56 inches diameter
+and 8 inches wide, with cast-iron driving-arms. Both
+wheels are drivers on curves as well as on straight lines.
+The engine is guided and fired by one man, and the total
+weight is so small that it will pass safely over any good
+country bridge. A brake is attached, to insure safety when
+going down-hill. Although designed to move at a speed
+of about three miles per hour, the velocity of the piston
+may be increased so that four miles per hour may be accomplished
+when necessary.</p>
+
+<p>This is an excellent example of this kind of engine as
+constructed at the present time. The strongly-built boiler,
+with its heater, the jacketed cylinder, and light, strong
+frame of the engine, the steel running-gear, the carefully-covered<span class='pagenum'><a name="Page_357" id="Page_357">[357]</a></span>
+surfaces of cylinder and boiler, and excellent proportions
+of details, are illustrations of good modern engineering,
+and are in curious contrast with the first of the
+class, built a century earlier by Smeaton.</p>
+
+<div class="figcenter"><a name="Fig118" id="Fig118"></a>
+<img src="images/illo383.png" alt="Fisher's Steam Carriage" width="500" height="242" />
+<p class="caption"><span class="smcap">Fig. 118.</span>&mdash;Fisher&#8217;s Steam-Carriage.</p></div>
+
+<p>Steam-carriages for passengers are now rarely built.
+<a href="#Fig118">Fig. 118</a> represents that designed by Fisher about 1870
+or earlier. It was only worked experimentally.</p>
+
+<div class="figcenter"><a name="Fig119" id="Fig119"></a>
+<img src="images/illo384.png" alt="Road and Farm Engine" width="504" height="350" />
+<p class="caption"><span class="smcap">Fig. 119.</span>&mdash;Road and Farm Locomotive.</p></div>
+
+<p>The <a href="#Fig119">above</a> is an engraving of a road and farm locomotive
+as built by one of the most successful among several
+British firms engaged in this work.</p>
+
+<p>The capacity of these engines has been determined by
+experiment by the author in the United States, and abroad
+by several distinguished engineers.</p>
+
+<p>The author made a trial of one of these engines at South
+Orange, N. J., to determine its power, speed, and convenience
+of working and man&oelig;uvring. The following were
+the principal dimensions:</p>
+
+<p class='pagenum'><a name="Page_358" id="Page_358">[358]</a></p>
+
+<table class="fsize80" summary="Principal Dimensions">
+
+<tr style="line-height: .1em;">
+<td style="width: 3.5em;">&nbsp;</td>
+<td style="width: 4em;">&nbsp;</td>
+<td style="width: 12em;">&nbsp;</td>
+<td style="width: 2em;">&nbsp;</td>
+<td style="width: 1em;">&nbsp;</td>
+<td style="width: 4em;">&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="3" class="left">Weight of engine, complete, 5 tons 4 cwt.</td>
+<td class="right">11,648</td>
+<td>&nbsp;</td>
+<td class="left padl1">pounds.</td>
+</tr>
+
+<tr>
+<td colspan="3" class="left">Steam-cylinder&mdash;diameter</td>
+<td class="right">7</td>
+<td class="left"><span class="enum">3</span>&#8725;<span class="denom">4</span></td>
+<td class="left padl1">inches.</td>
+</tr>
+
+<tr>
+<td colspan="3" class="left">Stroke of piston</td>
+<td class="right">10</td>
+<td>&nbsp;</td>
+<td class="left padl1">inches.</td>
+</tr>
+
+<tr>
+<td colspan="3" class="left">Revolution of crank to one of driving-wheels</td>
+<td class="right">17</td>
+<td colspan="2">&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="2" class="left">Driving-wheels&mdash;</td>
+<td class="left">diameter</td>
+<td class="right">60</td>
+<td>&nbsp;</td>
+<td class="left padl1">inches.</td>
+</tr>
+
+<tr>
+<td colspan="2" class="center">&#8222;</td>
+<td class="left">breadth of tire</td>
+<td class="right">10</td>
+<td>&nbsp;</td>
+<td class="left padl1">inches.</td>
+</tr>
+
+<tr>
+<td colspan="2" class="center">&#8222;</td>
+<td class="left">weight, each</td>
+<td class="right">450</td>
+<td>&nbsp;</td>
+<td class="left padl1">pounds.</td>
+</tr>
+
+<tr>
+<td class="left">Boiler&mdash;</td>
+<td colspan="2" class="left">length over all</td>
+<td class="right">8</td>
+<td>&nbsp;</td>
+<td class="left padl1">feet.</td>
+</tr>
+
+<tr>
+<td class="center">&#8222;</td>
+<td colspan="2" class="left">diameter of shell</td>
+<td class="right">30</td>
+<td>&nbsp;</td>
+<td class="left padl1">feet.</td>
+</tr>
+
+<tr>
+<td class="center">&#8222;</td>
+<td colspan="2" class="left">thickness of shell</td>
+<td class="right"><span class="enum">7</span>&#8725;<span class="denom">16</span></td>
+<td>&nbsp;</td>
+<td class="left padl1">inch.</td>
+</tr>
+
+<tr>
+<td class="center">&#8222;</td>
+<td colspan="2" class="left padr1">fire-box sheets, outside, thickness</td>
+<td class="right"><span class="enum">1</span>&#8725;<span class="denom">2</span></td>
+<td>&nbsp;</td>
+<td class="left padl1">inch.</td>
+</tr>
+
+<tr>
+<td colspan="3" class="left">Load on driving-wheels, 4 tons 10 cwt.</td>
+<td class="right">10,080</td>
+<td>&nbsp;</td>
+<td class="left padl1">pounds.</td>
+</tr>
+
+</table>
+
+<p>The boiler was of the ordinary locomotive type, and
+the engine was mounted upon it, as is usual with portable
+engines.</p>
+
+<p>The steam-cylinder was steam-jacketed, in accordance
+with the most advanced practice here and abroad. The
+crank-shaft and other wrought-iron parts subjected to heavy
+strains were strong and plainly finished. The gearing was
+of malleableized cast-iron, and all bearings, from crank-shaft
+to driving-wheel, on each side, were carried by a single
+sheet of half-inch plate, which also formed the sides of
+the fire-box exterior.</p>
+
+<p>The following is a summary of the conclusions deduced
+by the author from the trial, and published in the <i>Journal
+of the Franklin Institute</i>: A traction-engine may be so
+constructed as to be easily and rapidly man&oelig;uvred on the
+common road; and an engine weighing over 5 tons may be
+turned continuously without difficulty on a circle of 18 feet
+radius, or even on a road but little wider than the length
+of the engine. A locomotive of 5 tons 4 hundredweight
+has been constructed, capable of drawing on a good road
+23,000 pounds up a grade of 533 feet to the mile, at the rate
+of four miles an hour; and one might be constructed to
+draw more than 63,000 pounds up a grade of 225 feet to
+the mile, at the rate of two miles an hour.</p>
+
+<p>It was further shown that the coefficient of traction<span class='pagenum'><a name="Page_359" id="Page_359">[359]</a></span>
+with heavily-laden wagons on a good macadamized road
+is not far from .04; the traction-power of this engine is
+equal to that of 20 horses; the weight, exclusive of the
+weight of the engine, that could be drawn on a level road,
+was 163,452 pounds; and the amount of fuel required is
+estimated at 500 pounds a day. The advantages claimed
+for the traction-engine over horse-power are: no necessity
+for a limitation of working-hours; a difference in first cost
+in favor of steam; and in heavy work on a common road
+the expense by steam is less than 25 per cent. of the average
+cost of horse-power, a traction-engine capable of doing the
+work of 25 horses being worked at as little expense as 6 or
+8 horses. The cost of hauling heavy loads has been estimated
+at 7 cents per ton per mile.</p>
+
+<p>Such engines are gradually becoming useful in steam-ploughing.
+Two systems are adopted. In the one the engine
+is stationary, and hauls a &#8220;gang&#8221; of ploughs by means
+of a windlass and wire rope; in the other the engine traverses
+a field, drawing behind it a plough or a gang of
+ploughs. The latter method has been proposed for breaking
+up prairie-land.</p>
+
+<p>Thus, thirty years after the defeat of the intelligent,
+courageous, and persistent Hancock and his coworkers in
+the scheme of applying the steam-engine usefully on the
+common road, we find strong indications that, in a new
+form, the problem has been again attacked, and at least
+partially solved.</p>
+
+<p>One of the most important of the prerequisites to ultimate
+success in the substitution of steam for animal power
+on the highway is that our roads shall be well made. As
+the greatest care and judgment are exercised, and an immense
+outlay of capital is considered justifiable, in securing
+easy grades and a smooth track on our railroad routes, we
+may readily believe that similar precaution and outlay will
+be found advisable in adapting the common road to the
+road-locomotive. It would seem to the engineer that the<span class='pagenum'><a name="Page_360" id="Page_360">[360]</a></span>
+natural obstacles generally supposed to stand in the way
+have, after all, no real existence. The principal inconvenience
+that may be anticipated will probably arise from the
+carelessness or avarice of proprietors, which may sometimes
+cause them to appoint ignorant and inefficient engine-drivers,
+giving them charge of what are always excellent servants,
+but terrible masters. Nevertheless, as the transportation
+of passengers on railroads is found to be attended
+with less liability to loss of life or injury of person than
+their carriage by stage-coach, it will be found, very probably,
+that the general use of steam in transporting freight
+on common roads may be attended with less risk to life or
+property than to-day attends the use of horse-power.</p>
+
+<p>The <span class="smcap">Steam Fire-Engine</span> is still another form of portable
+engine. It is also one of the latest of all applications of
+steam-power. The steam fire-engine is peculiarly an American
+production. Although previously attempted, their
+permanently successful introduction has only occurred within
+the last fifteen years.</p>
+
+<div class="figcenter"><a name="Fig120" id="Fig120"></a>
+<img src="images/illo388.png" alt="Latta Steam Fire-Engine" width="474" height="350" />
+<p class="caption"><span class="smcap">Fig. 120.</span>&mdash;The Latta Steam Fire-Engine.</p></div>
+
+<p>As early as 1830, Braithwaite and Ericsson, of London,
+England, built an engine with steam and pump cylinders of
+7 and 6<span class="enum">1</span>&#8725;<span class="denom">2</span> inches diameter, respectively, with 16 inches stroke
+of piston. This machine weighed 2<span class="enum">1</span>&#8725;<span class="denom">2</span> tons, and is said to have
+thrown 150 gallons of water per minute to a height of between
+80 and 100 feet. It was ready for work in about 20
+minutes after lighting the fire. Braithwaite afterward supplied
+a more powerful engine to the King of Prussia, in
+1832. The first attempt made in the United States to construct
+a steam fire-engine was probably that of Hodge, who
+built one in New York in 1841. It was a strong and very effective
+machine, but was far too heavy for rapid transportation.
+The late J. K. Fisher, who throughout his life persistently
+urged the use of steam-carriages and traction-engines,
+designing and building several, also planned a steam fire-engine.
+Two were built from his design by the Novelty
+Works, New York, about 1860, for Messrs. Lee &amp; Larned.<span class='pagenum'><a name="Page_361" id="Page_361">[361]</a></span>
+They were &#8220;self-propellers,&#8221; and one of them, built for the
+city of Philadelphia, was sent to that city over the highway,
+driven by its own engines. The other was built for and used
+by the New York Fire Department, and did good service for
+several years. These engines were heavy, but very powerful,
+and were found to move at good speed under steam<span class='pagenum'><a name="Page_362" id="Page_362">[362]</a></span>
+and to man&oelig;uvre well. The Messrs. Latta, of Cincinnati,
+soon after succeeded in constructing comparatively light
+and very effective engines, and the fire department of that
+city was the first to adopt steam fire-engines definitely as
+their principal reliance. This change has now become general.</p>
+
+<p>The steam fire-engine has now entirely displaced the old
+hand-engine in all large cities. It does its work at a fraction
+of the cost of the latter. It can force its water to a
+height of 225 feet, and to a distance of more than 300 feet
+horizontally, while the hand-engine can seldom throw it
+one-third these distances; and the &#8220;steamer&#8221; may be relied
+upon to work at full power many hours if necessary, while
+the men at the hand-engine soon become fatigued, and require
+frequent relief. The city of New York has 40 steam
+fire-engines. One engine to every 10,000 inhabitants is a
+proper proportion.</p>
+
+<div class="figcenter"><a name="Fig121" id="Fig121"></a>
+<img src="images/illo390.png" alt="Amoskeag Engine, Section" width="484" height="350" />
+<p class="caption"><span class="smcap">Fig. 121.</span>&mdash;The Amoskeag Engine. Section.</p></div>
+
+<p>In the standard steam fire-engine (<a href="#Fig120">Fig. 120</a>) reciprocating
+engines and pumps are adopted, as seen in section in
+<a href="#Fig121">Fig. 121</a>, in which <i>A</i> is the furnace, and <i>B</i> the set of closely-set
+vertical fire-tubes in the boiler. <i>C</i> is the combustion-chamber,
+<i>D</i> the smoke-pipe, and <i>R</i> the steam-space.
+<i>E</i> is the steam-cylinder, and <i>F</i> the pump, which is seen to
+be double-acting. There are two pairs of engines and
+pumps, working on cranks, set at right angles, and turning
+a balance-wheel seen behind them. <i>G</i> is the feed-pump
+which supplies water to the boiler, <i>H</i> the air-chamber which
+equalizes the water-pressure, which reaches it through the
+pipe, <i>I J</i>. <i>K</i> is the feed-water tank, under the driver&#8217;s
+seat, <i>L</i>, which, with the engines and boiler, are carried on
+the frame, <i>M M</i>. The fireman stands on the platform, <i>N</i>.
+When it is necessary to move the machine, an endless
+chain connects the crank-shaft with the rear-wheels, and
+the engine, with pumps shut off, is thus made to drive the
+wheels at any desired speed.</p>
+
+<p>A self-propelling engine by the Amoskeag Company<span class='pagenum'><a name="Page_363" id="Page_363">[363]</a></span>
+had the following dimensions and performance: Weight, 4
+tons; speed, 8 miles per hour; steam-pressure, 75 pounds
+per square inch; height of stream from 1<span class="enum">1</span>&#8725;<span class="denom">4</span>-inch nozzle, 225
+feet; 1<span class="enum">3</span>&#8725;<span class="denom">4</span>-inch nozzle,
+150 feet; distance horizontally, 1<span class="enum">1</span>&#8725;<span class="denom">4</span>-inch<span
+class='pagenum'><a name="Page_365" id="Page_365">[364-365]</a></span><span class='pagenum'><a
+name="Page_364" id="Page_364"></a></span>
+nozzle, 300 feet; 1<span class="enum">3</span>&#8725;<span class="denom">4</span>-inch, 250 feet&mdash;a performance
+which contrasts wonderfully with that of the hand-worked
+fire-engine which these engines have now superseded.</p>
+
+<div class="figcenter"><a name="Fig122" id="Fig122"></a>
+<img src="images/illo391.png" alt="Silsby Rotary Steam Fire-Engine" width="553" height="350" />
+<p class="caption"><span class="smcap">Fig. 122.</span>&mdash;The Silsby Rotary Steam Fire-Engine.</p></div>
+
+<p>It has recently become common to construct the steam
+fire-engine with rotary engine and pump (<a href="#Fig122">Fig. 122</a>). The
+superiority of a rotary motion for a steam-engine is apparently
+so evident that many attempts have been made to
+overcome the practical difficulties to which it is subject.
+One of these difficulties, and the principal one, has been the
+packing of the part which performs the office of the piston
+in the straight cylinder. Robert Stephenson once expressed
+the opinion that a rotary engine would never be made to
+work successfully, on account of this difficulty of packing.
+The most palpable of the advantages of the rotary engine
+are the reduction in the size of the engine, claimed to result
+from the great velocity of the piston; the avoidance
+of great accidental strains, especially noticed in propelling
+ships; and a great saving of the power which is asserted to
+be expended in the reciprocating engine in overcoming the
+inertia while changing the direction of the motions. These
+advantages adapt the rotary engine, in an especial manner,
+to the driving of a locomotive or steam fire-engine.</p>
+
+<div class="figcenter"><a name="Fig123" id="Fig123"></a>
+<img src="images/illo392.png" alt="Rotary Steam-Engine" width="350" height="221" />
+<p class="caption"><span class="smcap">Fig. 123.</span>&mdash;Rotary Steam-Engine.</p></div>
+
+<div class="figcenter"><a name="Fig124" id="Fig124"></a>
+<img src="images/illo393.png" alt="Rotary Pump" width="350" height="241" />
+<p class="caption"><span class="smcap">Fig. 124.</span>&mdash;Rotary Pump.</p></div>
+
+<p>In the Holly rotary engine, seen in <a href="#Fig123">Fig. 123</a>, eccentrics
+and sliding-cams, which are frequently used in rotary engines,<span class='pagenum'><a name="Page_366" id="Page_366">[366]</a></span>
+and which are objectionable on account of their great
+friction, are avoided. Corrugated pistons, or irregular
+cams, <i>C D</i>, are adopted, forming chambers within the cases.
+In the engine the steam enters at <i>A</i>, at the bottom of the
+case, and presses the cams apart. The only packing used
+is in the ends of the long metal cogs, which are ground to
+fit the case and are kept out by the momentum of the cams,
+assisted by a slight spring back of the packing-pieces. The
+friction on the pump (<a href="#Fig124">Fig. 124</a>) is said to be less than in
+the engine. This is the reason given in support of the
+claim that the rotary engine forces water to a given distance
+with from one-fourth to one-third the steam-pressure
+necessary to drive all reciprocating engines. The smaller
+amount of power necessary to do the work, the less strain
+and consequent wear and tear upon the whole machine, are
+said to make it more durable and reliable. The pump being
+chambered, its liability to injury by the use of dirty or
+gritty water is lessened, and it is stated that it will last for
+years, pumping gritty water that would soon cut out a piston-pump.
+The pump used with this engine is, as shown in the
+above illustration, somewhat similar to the rotary engine
+driving it. Each of the revolving pistons has three long
+teeth bearing against the cylinder, and packed, to prevent
+leakage, like the engine-cams. They are carried on steel<span class='pagenum'><a name="Page_367" id="Page_367">[367]</a></span>
+shafts coupled to the engine-shafts. The water enters at
+<i>E</i> and is discharged at <i>F</i>, and the passages are purposely
+made large in order that sand, chips, and dirt, which may
+enter with the water, may pass through.</p>
+
+<p>The rotary engine is gradually coming into use for various
+special purposes, where small power is called for, and
+where economy of fuel is not important; but it has never
+yet competed, and may perhaps never in the future compete,
+with the reciprocating-piston engine where large engines
+are required, or where even moderate economy of fuel is
+essential. This form of engine has assumed so little importance,
+in fact, in the application of the steam-engine,
+that comparatively little is known of its history. Watt invented
+a rotary engine, and Yule many years afterward
+(1836) constructed such engines at Glasgow. Lamb patented
+another in 1842, Behrens still another in 1847. Napier,
+Hall, Massey, Holly, La France, and others, have
+built engines of this class in later times. Nearly all consist
+either of cams rotating in gear, as in those above
+sketched, or of a piston set radially in a cylinder of small
+diameter, which turns on its axis within a much larger cylinder
+set eccentrically, the piston, as the former turns, sliding
+in and out of the smaller cylinder as its outer edge
+slides in contact with the inner surface of the larger. In
+some forms of rotary engine, a piston revolves on a central
+shaft, and a sliding abutment in the external cylinder serves
+to separate the steam from the exhaust side and to confine
+the steam expanding while doing work. Nearly all of
+these combinations are also used as pumps.</p>
+
+<p>Fire-engines, made by the best-known American builders
+of engines, with reciprocating engines and pumps, such
+as are in general use in the United States, have become
+standard in general plan and arrangement of details. These
+are probably the best illustrations of extreme lightness,
+combined with strength of parts and working power, which
+have ever been produced in any branch of mechanical engineering.<span class='pagenum'><a name="Page_368" id="Page_368">[368]</a></span>
+By using a small boiler crowded with heating-surface,
+very carefully proportioned and arranged, and
+with small water-spaces; by adopting steel for running-gear
+and working parts wherever possible; by working at
+high piston-speed and with high steam-pressure; by selecting
+fuel with extreme care&mdash;by all these expedients, the
+steam fire-engine has been brought, in this country, to a
+state of efficiency far superior to anything seen elsewhere.
+Steam is raised with wonderful promptness, even from cold
+water, and water is thrown from the nozzle at the end of
+long lines of hose to great distances. But this combination
+of lightness with power is only attained at the expense of
+a certain regularity of action which can only be secured by
+greater water and steam capacity in the boiler. The small
+quantity of water contained within the boiler makes it necessary
+to give constant attention to the feed, and the tendency,
+almost invariably observed, to serious foaming and
+priming not only compels unintermitted care while running,
+but even introduces an element of danger which is not to
+be despised, even though the machine be in charge of the
+most experienced and skillful attendants. Even the greatest
+care, directed by the utmost skill, would not avail to prevent
+frequent explosions, were it not for the fact that it rarely,
+if ever, happens that accidents to such boilers occur from
+low water, unless the boiler is actually completely emptied
+of water. In driving them at fires, they frequently foam so
+violently that it is utterly impossible to obtain any clew to
+the amount of water present, and the attendant usually
+keeps his feed-pump on and allows the foaming to go on.
+As long as water is passing into the boiler it is very unlikely
+that any portion will become overheated and that accident
+will occur. Such management appears very reckless, and
+yet accident from such a cause is exceedingly rare.</p>
+
+<div class="figcenter"><a name="Fig125" id="Fig125"></a>
+<img src="images/illo396.png" alt="Tank-Engine, N. Y. Elevated Railroad" width="444" height="350" />
+<p class="caption"><span class="smcap">Fig. 125.</span>&mdash;Tank-Engine, New York Elevated Railroad.</p></div>
+
+<p>The changes which have been made in <span class="smcap">Locomotive-Construction</span>
+during the past few years have also been in
+the direction of the refinement of the earlier designs, and<span class='pagenum'><a name="Page_369" id="Page_369">[369]</a></span>
+have been accompanied by corresponding changes in all
+branches of railroad-work. The adjustment of parts to
+each other and proportioning them to their work, the
+modification of the minor details to suit changes of general
+dimensions, the improvement of workmanship, and the
+use of better material, have signalized this latest period.
+Special forms of engine have been devised for special
+kinds of work. Small, light tank-engines (<a href="#Fig125">Fig. 125</a>), carrying
+their own fuel and water without &#8220;tenders,&#8221; are used
+for moving cars about terminal stations and for making up
+trains; powerful, heavy, slow-moving engines, of large
+boiler-capacity and with small wheels, are used on steep
+gradients and for hauling long trains laden with coal and
+heavy merchandise; and hardly less powerful but quite
+differently proportioned &#8220;express&#8221;-engines are used for
+passenger and mail service.</p>
+
+<div class="figcenter"><a name="Fig126" id="Fig126"></a>
+<img src="images/illo397.png" alt="Forney's Tank-Locomotive" width="600" height="237" />
+<p class="caption"><span class="smcap">Fig. 126.</span>&mdash;Forney&#8217;s Tank-Locomotive.</p></div>
+
+<p>A peculiar form of engine (<a href="#Fig126">Fig. 126</a>) has been designed
+by Forney, in which the whole weight of engine, tender,
+coal, and water, is carried by one frame and on one set of
+wheels, the permanent weight falling on the driving-wheels
+and the variable load on the truck. These engines have also
+a comparatively short wheel-base and high pulling-power.
+The lightest tank-engines of the first class mentioned
+weigh 8 or 10 tons; but engines much lighter than these,<span class='pagenum'><a name="Page_370" id="Page_370">[370]</a></span>
+even, are built for mines, where they are sent into the galleries
+to bring out the coal-laden wagons. The heaviest
+engines of this class attain weights of 20 or 30 tons. The
+heaviest engine yet constructed in the United States is said
+to be one in use on the Philadelphia &amp; Reading Railroad,<span class='pagenum'><a name="Page_371" id="Page_371">[371]</a></span>
+having a weight of about 100,000 pounds, which is carried
+on 12 driving-wheels.</p>
+
+<div class="figcenter"><a name="Fig127" id="Fig127"></a>
+<img src="images/illo398.png" alt="British Express Engine" width="553" height="350" />
+<p class="caption"><span class="smcap">Fig. 127.</span>&mdash;British Express Engine.</p></div>
+
+<div class="figcenter"><a name="Fig128" id="Fig128"></a>
+<img src="images/illo399.png" alt="Baldwin Locomotive" width="600" height="259" />
+<p class="caption"><span class="smcap">Fig. 128.</span>&mdash;The Baldwin Locomotive. Section.</p></div>
+
+<p>A locomotive has two steam-cylinders, either side by
+side within the frame, and immediately beneath the forward
+end of the boiler, or on each side and exterior to the frame.
+The engines are non-condensing, and of the simplest possible
+construction. The whole machine is carried upon strong but
+flexible steel springs. The steam-pressure is usually more
+than 100 pounds. The pulling-power is generally about one-fifth
+the weight under most favorable conditions, and becomes
+as low as one-tenth on wet rails. The fuel employed
+is wood in new countries, coke in bituminous coal districts,
+and anthracite coal in the eastern part of the United States.
+The general arrangement and the proportions of locomotives
+differ somewhat in different localities. In <a href="#Fig127">Fig. 127</a>, a British
+express-engine, <i>O</i> is the boiler, <i>N</i> the fire-box, <i>X</i> the
+grate, <i>G</i> the smoke-box, and <i>P</i> the chimney. <i>S</i> is a spring
+and <i>R</i> a lever safety-valve, <i>T</i> is the whistle, <i>L</i> the throttle
+or regulator valve, <i>E</i> the steam-cylinder, and <i>W</i> the driving-wheel.
+The force-pump, <i>B C</i>, is driven from the cross-head,
+<i>D</i>. The frame is the base of the whole system, and
+all other parts are firmly secured to it. The boiler is made
+fast at one end, and provision is made for its expansion
+when heated. Adhesion is secured by throwing a proper<span class='pagenum'><a name="Page_372" id="Page_372">[372]</a></span>
+proportion of the weight upon the driving-wheel, <i>W</i>. This
+is from about 6,000 pounds on standard freight-engines,<span class='pagenum'><a name="Page_373" id="Page_373">[373]</a></span>
+having several pairs of drivers, to 10,000 pounds on passenger-engines,
+per axle. The peculiarities of the American
+type (<a href="#Fig128">Fig. 128</a>) are the truck, <i>I J</i>, or bogie, supporting the
+forward part of the engine, the system of equalizers, or
+beams which distribute the weight of the machine equally
+over the several axles, and minor differences of detail. The
+cab or house, <i>r</i>, protecting the engine-driver and fireman, is
+an American device, which is gradually coming into use
+abroad also. The American locomotive is distinguished by
+its flexibility and ease of action upon even roughly-laid
+roads. In the sketch, which shows a standard American
+engine in section, <i>A B</i> is the boiler, <i>C</i> one of the steam-cylinders,
+<i>D</i> the piston, <i>E</i> the cross-head, connected to the
+crank-shaft, <i>F</i>, by the connecting-rod, <i>G H</i> the driving-wheels,
+<i>I J</i> the truck-wheels, carrying the truck, <i>K L</i>;
+<i>N N</i> is the fire-box, <i>O O</i> the tubes, of which but four are
+shown. The steam-pipe, <i>R S</i>, leads the steam to the valve-chest,
+<i>T</i>, in which is seen the valve, moved by the valve-gear,
+<i>U V</i>, and the link, <i>W</i>. The link is raised or depressed
+by a lever, <i>X</i>, moved from the cab. The safety-valve
+is seen at the top of the dome, at <i>Y</i>, and the spring-balance
+by which the load is adjusted is shown at <i>Z</i>. At <i>a</i> is the
+cone-shaped exhaust-pipe, by which a good draught is secured.
+The attachments <i>b</i>, <i>c</i>, <i>d</i>, <i>e</i>, <i>f</i>, <i>g</i>&mdash;whistle, steam-gauge,
+sand-box, bell, head-light, and &#8220;cow-catcher&#8221;&mdash;are
+nearly all peculiar, either in construction or location, to the
+American locomotive. The cost of passenger-locomotives
+of ordinary size is about $12,000; heavier engines sometimes
+cost $20,000. The locomotive is usually furnished
+with a tender, which carries its fuel and water. The standard
+passenger-engine on the Pennsylvania Railroad has four
+driving-wheels, 5<span class="enum">1</span>&#8725;<span class="denom">2</span> feet diameter; steam-cylinders, 17 inches
+diameter and 2 feet stroke; grate-surface 15<span class="enum">1</span>&#8725;<span class="denom">2</span> square feet,
+and heating-surface 1,058 square feet. It weighs 63,100
+pounds, of which 39,000 pounds are on the drivers and
+24,100 on the truck. The freight-engine has six driving-wheels,<span class='pagenum'><a name="Page_374" id="Page_374">[374]</a></span>
+54<span class="enum">5</span>&#8725;<span class="denom">8</span> inches in diameter. The steam-cylinders are
+18 inches in diameter, stroke 22 inches, grate-surface 14.8
+square feet, heating-surface 1,096 feet. It weighs 68,500
+pounds, of which 48,000 are on the drivers and 20,500 on
+the truck. The former takes a train of five cars up an
+average grade of 90 feet to the mile. The latter is attached<span class='pagenum'><a name="Page_375" id="Page_375">[375]</a></span>
+to a train of 11 cars. On a grade of 50 feet to the mile,
+the former takes 7 and the latter 17 cars. Tank-engines
+for very heavy work, such as on grades of 320 feet to the
+mile, which are found on some of the mountain lines of
+road, are made with five pairs of driving-wheels, and with
+no truck. The steam-cylinders are 20<span class="enum">1</span>&#8725;<span class="denom">8</span> inches in diameter,
+2 feet stroke; grate-area, 15<span class="enum">3</span>&#8725;<span class="denom">4</span> feet; heating-surface, 1,380
+feet; weight with tank full, and full supply of wood,
+112,000 pounds; average weight, 108,000 pounds. Such
+an engine has hauled 110 tons up this grade at the speed
+of 5 miles an hour, the steam-pressure being 145 pounds.
+The adhesion was about 23 per cent. of the weight.</p>
+
+<div class="figcenter"><a name="Fig129" id="Fig129"></a>
+<img src="images/illo401.png" alt="American Type of Express-Engine" width="566" height="250" />
+<p class="caption"><span class="smcap">Fig. 129.</span>&mdash;The American Type of Express-Engine, 1878.</p></div>
+
+<p>In checking a train in motion, the inertia of the engine
+itself absorbs a seriously large portion of the work of the
+brakes. This is sometimes reduced by reversing the engine
+and allowing the steam-pressure to act in aid of the brakes.
+To avoid injury by abrasion of the surfaces of piston, cylinder,
+and the valves and valve-seats, M. Le Chatelier introduces
+a jet of steam into the exhaust-passages when
+reversing, and thus prevents the ingress of dust-laden air
+and the drying of the rubbing surfaces. This method of
+checking a train is rarely resorted to, however, except in
+case of danger. The introduction of the &#8220;continuous&#8221; or
+&#8220;air&#8221; brake, which can be thrown into action in an instant
+on every car of the train by the engine-driver, is so efficient
+that it is now almost universally adopted. It is one of the
+most important safeguards which American ingenuity has
+yet devised. In drawing a train weighing 150 tons at the
+rate of 60 miles an hour, about 800 effective horse-power is
+required. A speed of 80 miles an hour has been often
+attained, and 100 miles has probably been reached.</p>
+
+<p>The American locomotive-engine has a maximum life
+which may be stated at about 30 years. The annual cost
+of repairs is from 10 to 15 per cent. of its first cost. On
+moderately level roads, the engine requires a pint of oil to
+each 25 miles, and a ton of coal to each 40 or 50 miles run.<span class='pagenum'><a name="Page_376" id="Page_376">[376]</a></span>
+One of the best-managed railroads in the United States reports
+expenses as follows for one month:</p>
+
+<table class="fsize80" summary="Monthly Railroad Expenses">
+
+<tr>
+<td class="lr05">Number &#8220;train-miles&#8221; run per ton of coal burned</td>
+<td class="right">53.95</td>
+</tr>
+
+<tr>
+<td class="lr05">Number &#8220;train-miles&#8221; run per quart of oil used</td>
+<td class="right">34.44</td>
+</tr>
+
+<tr>
+<td class="lr05">Passenger-cars hauled 1 mile per ton of coal</td>
+<td class="right">275.7</td>
+</tr>
+
+<tr>
+<td class="lr05">Other cars hauled 1 mile per ton of coal</td>
+<td class="right">634.8</td>
+</tr>
+
+<tr>
+<td class="lr05">Cost repairs per mile run</td>
+<td class="right">$2&nbsp;43</td>
+</tr>
+
+<tr>
+<td class="lr05">Cost fuel per mile run</td>
+<td class="right">3&nbsp;64</td>
+</tr>
+
+<tr>
+<td class="lr05">Cost oil and waste per mile run</td>
+<td class="right">62</td>
+</tr>
+
+<tr>
+<td class="lr05">Cost wages of engine-men per mile run</td>
+<td class="right">6&nbsp;22</td>
+</tr>
+
+<tr>
+<td class="lr05">All other expenses per mile</td>
+<td class="right">1&nbsp;91</td>
+</tr>
+
+<tr>
+<td class="lr05">Total cost per &#8220;train-mile&#8221; run</td>
+<td class="right">14&nbsp;82</td>
+</tr>
+
+</table>
+
+<p>Although the above sketch and description represent
+the construction and performance of the standard locomotive
+of the present time, there are indications that the compound
+arrangement of engines will ultimately be adopted.
+This will involve a considerable change of proportions,
+greatly increasing the volume and weight of steam-cylinders,
+but enabling the designer to more than proportionally
+decrease the weight of boiler and the quantity of
+fuel carried. There is no serious objection to their use,
+however, and no insuperable difficulty in the construction
+of the &#8220;double-cylinder&#8221; type of engine for the locomotive.
+A few such engines have already been put in service.
+In these engines the high-pressure cylinder is placed
+on one side and the larger low-pressure cylinder on the other
+side of the locomotive, thus having but two cylinders, as in
+the older plan. The valve-gear is the Stephenson link, as
+in the ordinary engine. At starting, the steam is allowed
+to act on both pistons; but after a few revolutions the
+course of the steam is changed, and the exhaust from the
+smaller cylinder, instead of passing into the chimney, is
+sent to the larger cylinder, which is at the same time
+cut off from the main steam-pipe. When the engine is
+ascending a steep gradient the steam may, if necessary, be
+taken from the boiler into both cylinders, as when starting.<span class='pagenum'><a name="Page_377" id="Page_377">[377]</a></span>
+Compound engines of this kind have been used on the
+French line of railroad from Bayonne to Biarritz. They
+were designed by Mallet and built at Le Creuzot. The
+steam-cylinders are of 9<span class="enum">1</span>&#8725;<span class="denom">2</span> and
+15<span class="enum">3</span>&#8725;<span class="denom">4</span> inches diameter, and of
+17<span class="enum">3</span>&#8725;<span class="denom">4</span> inches stroke of piston. The four driving-wheels are
+4 feet in diameter, and the total weight of engine is 20
+tons. The boiler has 484<span class="enum">1</span>&#8725;<span class="denom">2</span> square feet of heating-surface,
+and is built to carry 10 atmospheres pressure. When hauling
+trains of 50 tons at 25 miles an hour, these engines require
+about 15 pounds of good coal per mile.</p>
+
+<p>The total length of the railways in operation in the
+United States on the 1st day of January, 1877, was 76,640
+miles,<a name="FNanchor_93_93" id="FNanchor_93_93"></a><a href="#Footnote_93_93" class="fnanchor">[93]</a>
+being an average of one mile of railway for every
+600 inhabitants. The railways are as follows:</p>
+
+<table class="fsize80" summary="U. S. Railroads 1877">
+
+<tr>
+<td>&nbsp;</td>
+<td class="right br padr1">Miles.</td>
+<td>&nbsp;</td>
+<td class="right br padr1">Miles.</td>
+<td>&nbsp;</td>
+<td class="right">Miles.</td>
+</tr>
+
+<tr>
+<td class="left padl1 padr1">Alabama</td>
+<td class="right br padr1">1,722</td>
+<td class="left padl1 padr1">Kentucky</td>
+<td class="right br padr1">1,464</td>
+<td class="left padl1 padr1">Ohio</td>
+<td class="right">4,680</td>
+</tr>
+
+<tr>
+<td class="left padl1 padr1">Alaska</td>
+<td class="right br padr1">0</td>
+<td class="left padl1 padr1">Louisiana</td>
+<td class="right br padr1">539</td>
+<td class="left padl1 padr1">Oregon</td>
+<td class="right">251</td>
+</tr>
+
+<tr>
+<td class="left padl1 padr1">Arizona</td>
+<td class="right br padr1">0</td>
+<td class="left padl1 padr1">Maine</td>
+<td class="right br padr1">987</td>
+<td class="left padl1 padr1">Pennsylvania</td>
+<td class="right">5,896</td>
+</tr>
+
+<tr>
+<td class="left padl1 padr1">Arkansas</td>
+<td class="right br padr1">787</td>
+<td class="left padl1 padr1">Maryland</td>
+<td class="right br padr1">1,092</td>
+<td class="left padl1 padr1">Rhode Island</td>
+<td class="right">182</td>
+</tr>
+
+<tr>
+<td class="left padl1 padr1">California</td>
+<td class="right br padr1">1,854</td>
+<td class="left padl1 padr1">Massachusetts</td>
+<td class="right br padr1">1,825</td>
+<td class="left padl1 padr1">South Carolina</td>
+<td class="right">1,352</td>
+</tr>
+
+<tr>
+<td class="left padl1 padr1">Colorado</td>
+<td class="right br padr1">950</td>
+<td class="left padl1 padr1">Michigan</td>
+<td class="right br padr1">3,437</td>
+<td class="left padl1 padr1">Tennessee</td>
+<td class="right">1,638</td>
+</tr>
+
+<tr>
+<td class="left padl1 padr1">Connecticut</td>
+<td class="right br padr1">925</td>
+<td class="left padl1 padr1">Minnesota</td>
+<td class="right br padr1">2,024</td>
+<td class="left padl1 padr1">Texas</td>
+<td class="right">2,072</td>
+</tr>
+
+<tr>
+<td class="left padl1 padr1">Dakota</td>
+<td class="right br padr1">290</td>
+<td class="left padl1 padr1">Mississippi</td>
+<td class="right br padr1">1,028</td>
+<td class="left padl1 padr1">Utah</td>
+<td class="right">486</td>
+</tr>
+
+<tr>
+<td class="left padl1 padr1">Delaware</td>
+<td class="right br padr1">285</td>
+<td class="left padl1 padr1">Missouri</td>
+<td class="right br padr1">3,016</td>
+<td class="left padl1 padr1">Vermont</td>
+<td class="right">810</td>
+</tr>
+
+<tr>
+<td class="left padl1 padr1">Florida</td>
+<td class="right br padr1">484</td>
+<td class="left padl1 padr1">Montana</td>
+<td class="right br padr1">0</td>
+<td class="left padl1 padr1">Virginia</td>
+<td class="right">1,648</td>
+</tr>
+
+<tr>
+<td class="left padl1 padr1">Georgia</td>
+<td class="right br padr1">2,308</td>
+<td class="left padl1 padr1">Nebraska</td>
+<td class="right br padr1">1,181</td>
+<td class="left padl1 padr1">Washington</td>
+<td class="right">110</td>
+</tr>
+
+<tr>
+<td class="left padl1 padr1">Idaho</td>
+<td class="right br padr1">0</td>
+<td class="left padl1 padr1">Nevada</td>
+<td class="right br padr1">714</td>
+<td class="left padl1 padr1">West Virginia</td>
+<td class="right">576</td>
+</tr>
+
+<tr>
+<td class="left padl1 padr1">Illinois</td>
+<td class="right br padr1">6,980</td>
+<td class="left padl1 padr1">New Hampshire</td>
+<td class="right br padr1">942</td>
+<td class="left padl1 padr1">Wisconsin</td>
+<td class="right">2,575</td>
+</tr>
+
+<tr>
+<td class="left padl1 padr1">Indiana</td>
+<td class="right br padr1">4,072</td>
+<td class="left padl1 padr1">New Jersey</td>
+<td class="right br padr1">1,594</td>
+<td class="left padl1 padr1">Wyoming</td>
+<td class="right">459</td>
+</tr>
+
+<tr>
+<td class="left padl1 padr1">Indian Territory</td>
+<td class="right br padr1">281</td>
+<td class="left padl1 padr1">New Mexico</td>
+<td class="right br padr1">0</td>
+<td colspan="2">&nbsp;</td>
+</tr>
+
+<tr>
+<td class="left padl1 padr1">Iowa</td>
+<td class="right br padr1">3,937</td>
+<td class="left padl1 padr1">New York</td>
+<td class="right br padr1">5,520</td>
+<td class="left padl1 padr1">Total</td>
+<td class="right bt">76,640</td>
+</tr>
+
+<tr>
+<td class="left padl1 padr1">Kansas</td>
+<td class="right br padr1">3,226</td>
+<td class="left padl1 padr1">North Carolina</td>
+<td class="right br padr1">1,371</td>
+<td>&nbsp;</td>
+<td>&nbsp;</td>
+</tr>
+
+</table>
+
+<p>In 1873 came the great financial crisis, with its terrible
+results of interrupted production, poverty, and starvation,
+and an almost total cessation of the work of building new
+railroads. The largest number of miles ever built in any
+one year were constructed in 1872. The greatest mileage
+is in Illinois, reaching 6,589; the smallest in Rhode
+Island, 136, and in Washington Territory, 110. The
+State of Massachusetts has one mile of railroad to 4.86<span class='pagenum'><a name="Page_378" id="Page_378">[378]</a></span>
+miles of territory, this ratio being the greatest in the country.
+The longest road in operation is the Chicago &amp; Northwestern,
+extending 1,500 miles; the shortest, the Little
+Saw-Mill Run Road in Pennsylvania, which is but three
+miles in length. The total capital of railways in the country
+is $6,000,000,000, or an average of $100,000 per mile.
+The earnings for the year 1872 amounted to $454,969,000,
+or $7,500 per mile. The largest net earnings recorded as
+made on any road were gained by the New York Central
+&amp; Hudson River, $8,260,827; the smallest on several
+roads which not only earned nothing, but incurred a loss.</p>
+
+<p>The catastrophe of 1873-&#8217;74 revealed the fact that the
+latter condition of railroad finances was vastly more common
+than had been suspected; and it is still doubtful
+whether the existing immense network of railroads which
+covers the United States can be made, as a whole, to pay
+even a moderate return on the money invested in their construction.
+At the period of maximum rate of extension of
+railroads in the United States&mdash;1873&mdash;the reported lengths
+of the railroads of Europe and America were as follows:<a name="FNanchor_94_94"
+id="FNanchor_94_94"></a><a href="#Footnote_94_94" class="fnanchor">[94]</a></p>
+
+<p class="center smcap">Railroads in Europe and America in 1873.</p>
+
+<table class="fsize80" summary="Railroads in Europe and America">
+
+<tr>
+<td class="center bt br">COUNTRIES.</td>
+<td class="center bt br padl1 padr1">Railroads,<br />Miles.</td>
+<td class="center bt br padl1 padr1">Population</td>
+<td class="center bt padl1 padr1">Area,<br />Sq. Miles.</td>
+</tr>
+
+<tr>
+<td class="left bt br">United States</td>
+<td class="right bt br padr2">71,565</td>
+<td class="right bt br padr1">40,232,000</td>
+<td class="right bt padr1">2,492,316</td>
+</tr>
+
+<tr>
+<td class="left br">Germany</td>
+<td class="right br padr2">12,207</td>
+<td class="right br padr1">40,111,265</td>
+<td class="right padr1">212,091</td>
+</tr>
+
+<tr>
+<td class="left br">Austria</td>
+<td class="right br padr2">5,865</td>
+<td class="right br padr1">35,943,592</td>
+<td class="right padr1">227,234</td>
+</tr>
+
+<tr>
+<td class="left br">France</td>
+<td class="right br padr2">10,333</td>
+<td class="right br padr1">36,469,875</td>
+<td class="right padr1">201,900</td>
+</tr>
+
+<tr>
+<td class="left br">Russia in Europe</td>
+<td class="right br padr2">7,044</td>
+<td class="right br padr1">71,207,794</td>
+<td class="right padr1">1,992,574</td>
+</tr>
+
+<tr>
+<td class="left br">Great Britain, 1872</td>
+<td class="right br padr2">15,814</td>
+<td class="right br padr1">31,817,108</td>
+<td class="right padr1">120,769</td>
+</tr>
+
+<tr>
+<td class="left br">Belgium</td>
+<td class="right br padr2">1,301</td>
+<td class="right br padr1">4,839,094</td>
+<td class="right padr1">11,412</td>
+</tr>
+
+<tr>
+<td class="left br">Netherlands</td>
+<td class="right br padr2">886</td>
+<td class="right br padr1">3,858,055</td>
+<td class="right padr1">13,464</td>
+</tr>
+
+<tr>
+<td class="left br">Switzerland</td>
+<td class="right br padr2">820</td>
+<td class="right br padr1">2,669,095</td>
+<td class="right padr1">15,233</td>
+</tr>
+
+<tr>
+<td class="left br">Italy</td>
+<td class="right br padr2">3,667</td>
+<td class="right br padr1">26,273,776</td>
+<td class="right padr1">107,961</td>
+</tr>
+
+<tr>
+<td class="left br">Denmark</td>
+<td class="right br padr2">420</td>
+<td class="right br padr1">1,784,741</td>
+<td class="right padr1">14,453</td>
+</tr>
+
+<tr>
+<td class="left br">Spain</td>
+<td class="right br padr2">3,401</td>
+<td class="right br padr1">16,301,850</td>
+<td class="right padr1">182,758</td>
+</tr>
+
+<tr>
+<td class="left br">Portugal</td>
+<td class="right br padr2">453</td>
+<td class="right br padr1">3,987,867</td>
+<td class="right padr1">36,510</td>
+</tr>
+
+<tr>
+<td class="left br padr1">Sweden and Norway</td>
+<td class="right br padr2">1,049</td>
+<td class="right br padr1">5,860,122</td>
+<td class="right padr1">188,771</td>
+</tr>
+
+<tr>
+<td class="left br bb">Greece</td>
+<td class="right br bb padr2">100</td>
+<td class="right br bb padr1">1,332,508</td>
+<td class="right bb padr1">19,941</td>
+</tr>
+
+</table>
+
+<p><span class='pagenum'><a name="Page_379" id="Page_379">[379]</a></span>The railroads in Great Britain comprise over 15,000 miles
+of track now being worked in the United Kingdom, on which
+have been expended $2,800,000,000. This sum is equal to five
+times the amount of the annual value of all the real property
+in Great Britain, and two-thirds of the national debt.
+After deducting all the working expenses, the gross net
+annual revenue of all the roads exceeds by $110,000,000 the
+total revenue from all sources of Belgium, Holland, Portugal,
+Denmark, Sweden and Norway. An army of 100,000
+officers and servants is in the employ of the companies,
+and the value of the rolling-stock exceeds $150,000,000.</p>
+
+
+<h4><span class="smcap">Section III.&mdash;Marine Engines.</span></h4>
+
+<p>The changes which have now become completed in the
+marine steam-engine have been effected at a later date than
+those which produced the modern locomotive. On the
+American rivers the modification of the beam-engine since
+the time of Robert L. Stevens has been very slight. The
+same general arrangement is retained, and the details are
+little, if at all, altered. The pressure of steam is sometimes
+as high as 60 pounds per square inch.</p>
+
+<div class="figcenter"><a name="Fig130" id="Fig130"></a>
+<img src="images/illo407.png" alt="BeamEngine" width="350" height="457" />
+<p class="caption"><span class="smcap">Fig. 130.</span>&mdash;Beam-Engine.</p></div>
+
+<p>The valves are of the disk or poppet variety, rising and
+falling vertically. They are four in number, two steam
+and two exhaust valves being placed at each end of the
+steam-cylinder. The beam-engine is a peculiarly American
+type, seldom if ever seen abroad. <a href="#Fig130">Fig. 130</a> is an outline
+sketch of this engine as built for a steamer plying on the
+Hudson River. This class of engine is usually adopted in
+vessels of great length, light draught, and high speed.
+But one steam-cylinder is commonly used. The cross-head
+is coupled to one end of the beam by means of a pair of
+links, and the motion of the opposite end of the beam is
+transmitted to the crank by a connecting-rod of moderate
+length. The beam has a cast-iron centre surrounded by a
+wrought-iron strap of lozenge shape, in which are forged<span class='pagenum'><a name="Page_380" id="Page_380">[380]</a></span>
+the bosses for the end-centres, or for the pins to which the
+connecting-rod and the links are attached. The main centre
+of the beam is supported by a &#8220;gallows-frame&#8221; of timbers
+so arranged as to receive all stresses longitudinally.
+The crank and shaft are of wrought-iron. The valve-gear
+is usually of the form already mentioned as the Stevens
+valve-gear, the invention of Robert L. and Francis B. Stevens.
+The condenser is placed immediately beneath the<span class='pagenum'><a name="Page_381" id="Page_381">[381]</a></span>
+steam-cylinder. The air-pump is placed close beside it, and
+worked by a rod attached to the beam. Steam-vessels on
+the Hudson River have been driven by such engines at the
+rate of 20 miles an hour. This form of engine is remarkable
+for its smoothness of operation, its economy and durability,
+its compactness, and the latitude which it permits in
+the change of shape of the long, flexible vessels in which it
+is generally used, without injury by &#8220;getting out of line.&#8221;</p>
+
+<div class="figcenter"><a name="Fig131" id="Fig131"></a>
+<img src="images/illo408.png" alt="Oscillating Engine and Feathering Paddle Wheel" width="382" height="350" />
+<p class="caption"><span class="smcap">Fig. 131.</span>&mdash;Oscillating Engine and Feathering Paddle-Wheel.</p></div>
+
+<p>For paddle-engines of large vessels, the favorite type,
+which has been the side-lever engine, is now rarely built. For
+smaller vessels, the oscillating engine with feathering paddle-wheels
+is still largely employed in Europe. This style
+of engine is shown in <a href="#Fig131">Fig. 131</a>. It is very compact, light,
+and moderately economical, and excels in simplicity. The
+usual arrangement is such that the feathering-wheel has the
+same action upon the water as a radial wheel of double
+diameter. This reduction of the diameter of the wheel,
+while retaining maximum effectiveness, permits a high
+speed of engine, and therefore less weight, volume, and
+cost. The smaller wheel-boxes, by offering less resistance
+to the wind, retard the progress of the vessel less than those<span class='pagenum'><a name="Page_382" id="Page_382">[382]</a></span>
+of radial wheels. Inclined engines are sometimes used for
+driving paddle-wheels. In these the steam-cylinder lies in
+an inclined position, and its connecting-rod directly connects
+the crank with the cross-head. The condenser and
+air-pump usually lie beneath the cross-head guides, and are
+worked by a bell-crank driven by links on each side the
+connecting-rod, attached to the cross-head. Such engines
+are used to some extent in Europe, and they have been
+adopted in the United States navy for side-wheel gunboats.
+They are also used on the ferry-boats plying between New
+York and Brooklyn.</p>
+
+<div class="figcenter"><a name="Fig132" id="Fig132"></a>
+<img src="images/illo410.png" alt="The Two Rhode Islands" width="500" height="242" />
+<p class="caption"><span class="smcap">Fig. 132.</span>&mdash;The Two Rhode Islands, 1836-1876.</p></div>
+
+<p>Among the finest illustrations of recent practice in the
+construction of side-wheel steamers are those built for the
+several routes between New York and the cities of New
+England which traverse Long Island Sound. Our <a href="#Fig132">illustration</a>
+exhibits the form of these vessels, and also shows well
+the modifications in structure and size which have been
+made during this generation. The later vessel is 325 feet
+long, 45 feet beam, 80 feet wide over the &#8220;guards,&#8221; and 16
+feet deep, drawing 10 feet of water. The &#8220;frames&#8221; upon
+which the planking of the hull is fastened are of white-oak,
+and the lighter and &#8220;top&#8221; timbers of cedar and locust.
+The engine has a steam-cylinder 90 inches in diameter and
+12 feet stroke of piston.<a name="FNanchor_95_95" id="FNanchor_95_95"></a><a href="#Footnote_95_95"
+class="fnanchor">[95]</a> On each side the great saloons
+which extend from end to end of the upper deck are state-rooms,
+containing each two berths and elegantly furnished.
+The engine of this vessel is capable of developing about
+2,500 horse-power. The great wheels, of which the paddle-boxes
+are seen rising nearly to the height of the hurricane-deck,
+are 37<span class="enum">1</span>&#8725;<span class="denom">2</span> feet in diameter and 12 in breadth. The hull
+of this vessel, including all wood-work, weighs over 1,200
+tons. The weight of the machinery is about 625 tons.
+The steamer makes 16 knots an hour when the engine is at
+its best speed&mdash;about 17 revolutions per minute&mdash;and its<span class='pagenum'><a name="Page_383" id="Page_383">[383]</a></span>
+average speed is about 14 knots on its route of 160 miles.
+The coal required to supply the furnaces of such a vessel
+and with such machinery would be about 3 tons per hour.<span class='pagenum'><a name="Page_384" id="Page_384">[384]</a></span>
+or a little over 2<span class="enum">1</span>&#8725;<span class="denom">2</span> pounds per horse-power. The construction
+of such a vessel occupies, usually, about a year, and
+costs a quarter of a million dollars.</p>
+
+<div class="figcenter"><a name="Fig133" id="Fig133"></a>
+<img src="images/illo411.png" alt="Mississippi Steamboat" width="374" height="350" />
+<p class="caption"><span class="smcap">Fig. 133.</span>&mdash;A Mississippi Steamboat.</p></div>
+
+<p>The non-condensing direct-acting engine is used principally
+on the Western rivers, driven by steam of from 100
+to 150 pounds pressure, and exhausts its steam into the atmosphere.
+It is the simplest possible form of direct-acting
+engine. The valves are usually of the &#8220;poppet&#8221; variety,
+and are operated by cams which act at the ends of long
+levers having their fulcra on the opposite side of the valve,
+the stem of which latter is attached at an intermediate
+point. The engine is horizontal, and the connecting-rod
+directly attached to cross-head and crank-pin without intermediate
+mechanism. The paddle-wheel is used, sometimes
+as a stern-wheel, as in the plan of Jonathan Hulls of one and<span class='pagenum'><a name="Page_385" id="Page_385">[385]</a></span>
+a half century ago, sometimes as a side-wheel, as is most
+usual elsewhere. One of the most noted of these steamers,
+plying on the Mississippi, is shown in the preceding <a href="#Fig133">sketch</a>.</p>
+
+<p>One of the largest of these steamers was the Grand
+Republic,<a name="FNanchor_96_96" id="FNanchor_96_96"></a><a href="#Footnote_96_96" class="fnanchor">[96]</a>
+a vessel 340 feet long, 56 feet beam, and 10<span class="enum">1</span>&#8725;<span class="denom">4</span> feet
+depth. The draught of water of this great craft was 3<span class="enum">1</span>&#8725;<span class="denom">2</span>
+feet forward and 4<span class="enum">1</span>&#8725;<span class="denom">2</span> aft. The two sets of compound engines,
+28 and 56 inches diameter and of 10 feet stroke, drive
+wheels 38<span class="enum">1</span>&#8725;<span class="denom">2</span> feet in diameter and 18 feet wide. The boilers
+were steel. A steamer built still later on the Ohio has the
+following dimensions: Length, 225 feet; breadth, 35<span class="enum">1</span>&#8725;<span class="denom">2</span> feet;
+depth, 5 feet; cylinders, 17<span class="enum">3</span>&#8725;<span class="denom">8</span> inches in diameter, 6 feet
+stroke; three boilers. The hull and cabin were built at
+Jeffersonville, Ind. She has 40 large state-rooms. The
+cost of the steamer was $40,000.</p>
+
+<p>These vessels have now opened to commerce the whole
+extent of the great Mississippi basin, transporting a large
+share of the products of a section of country measuring a
+million and a half square miles&mdash;an area equal to many
+times that of New York State, and twelve times that of
+the island of Great Britain&mdash;an area exceeding that of the
+whole of Europe, exclusive of Russia and Turkey, and capable,
+if as thoroughly cultivated as the Netherlands, of supporting
+a population of between three and four hundred
+millions of people.</p>
+
+<p>The steam-engine and propelling apparatus of the modern
+ocean-steamer have now become almost exclusively the
+compound or double-cylinder engine, driving the screw.
+The form and the location of the machinery in the vessel
+vary with the size and character of the ship which it drives.
+Very small boats are fitted with machinery of quite a different
+kind from that built for large steamers, and war-vessels
+have usually been supplied with engines of a design
+radically different from that adopted for merchant-steamers.</p>
+
+<div class="figcenter"><a name="Fig134" id="Fig134"></a>
+<img src="images/illo413.png" alt="Steam-Launch" width="550" height="262" />
+<p class="caption"><span class="smcap">Fig. 134.</span>&mdash;Steam-Launch, New York Steam-Power Company.</p></div>
+
+<p>The introduction of <i><a href="#Fig134">Steam-Launches</a></i> and small pleasure-boats<span class='pagenum'><a name="Page_386" id="Page_386">[386]</a></span>
+driven by steam-power is of comparatively recent
+date, but their use is rapidly increasing. Those first built
+were heavy, slow, and complicated; but, profiting by experience,
+light and graceful boats are now built, of remarkable
+swiftness, and having such improved and simplified
+machinery that they require little fuel and can be easily<span class='pagenum'><a name="Page_387" id="Page_387">[387]</a></span>
+managed. Such boats have strong, carefully-modeled hulls,
+light and strong boilers, capable of making a large amount
+of dry steam with little fuel, and a light, quick-running engine,
+working without shake or jar, and using steam economically.</p>
+
+<div class="figcenter"><a name="Fig135" id="Fig135"></a>
+<img src="images/illo414.png" alt="Launch-Engine" width="292" height="550" />
+<p class="caption"><span class="smcap">Fig. 135.</span>&mdash;Launch-Engine.</p></div>
+
+<p>The above <a href="#Fig135">sketch</a> represents the engine built by a New
+York firm for such little craft. This is the smallest size
+made for the market. It has a steam-cylinder 3 inches in
+diameter and a stroke of piston of 5 inches, driving a screw
+26 inches in diameter and of 3 feet pitch. The maximum<span class='pagenum'><a name="Page_388" id="Page_388">[388]</a></span>
+power of the engine is four or five times the nominal power.
+The boiler is of the form shown in the illustrations of semi-portable
+engines, and has a heating-surface, in this case,
+of 75 square feet. The boat itself is like that seen on page
+386, and is 25 feet long, of 5 feet 8 inches beam, and draws
+2<span class="enum">1</span>&#8725;<span class="denom">4</span> feet of water. These little machines weigh about 150
+pounds per nominal horse-power, and the boilers about 300.</p>
+
+<p>Some of these little vessels have attained wonderful
+speed. A British steam-yacht, the Miranda, 45<span class="enum">1</span>&#8725;<span class="denom">2</span> feet in
+length, 5<span class="enum">3</span>&#8725;<span class="denom">4</span> feet wide, and drawing 2<span class="enum">1</span>&#8725;<span class="denom">2</span> feet of water, with a
+total weight of 3<span class="enum">3</span>&#8725;<span class="denom">4</span>
+tons, has steamed nearly 18<span class="enum">1</span>&#8725;<span class="denom">2</span> miles an
+hour for short runs. The boat was driven by an engine of
+6 inches diameter of cylinder and 8 inches stroke of piston,
+making 600 revolutions per minute, driving a two-bladed
+screw 2<span class="enum">1</span>&#8725;<span class="denom">2</span> feet in diameter and of
+3<span class="enum">1</span>&#8725;<span class="denom">3</span> feet pitch. Its machinery
+had a total weight of two tons. Another English
+yacht, the Firefly, is said to have made 18.94 miles an hour.
+A little French yacht, the Hirondelle, has attained a speed
+of 16 knots, equal to about 18<span class="enum">1</span>&#8725;<span class="denom">2</span> miles, an hour. This was,
+however, a much larger vessel than the preceding. One of
+the most remarkable of these little steamers is a torpedo-boat
+built for the United States navy. This vessel is 60
+feet long, 6 feet wide, and 5 feet deep; its screw is 38
+inches in diameter and of 5 feet pitch, two-bladed, and is
+driven, by a very light engine and boiler, 400 revolutions
+per minute, the boat attaining a speed of 19 to 20 miles an
+hour. Another little vessel, the Vision, made nearly as
+great speed, developing 20 horse-power with engine and
+boiler weighing but about 400 pounds.</p>
+
+<p>Yachts of high speed require such weight and bulk of
+engine that but little space is left for cabins, and they are
+usually exceedingly uncomfortable vessels. In the Miranda
+the weight of machinery is more than one-half the total
+weight of the whole. An illustration of the more comfortable
+and more generally liked pleasure-yacht is the Day
+Dream. The length is 105 feet, and the boat draws 5<span class="enum">1</span>&#8725;<span class="denom">2</span><span class='pagenum'><a name="Page_389" id="Page_389">[389]</a></span>
+feet of water. There are two engines, having steam-cylinders
+14 inches in diameter and of the same length of stroke,
+direct-acting, condensing, and driving a screw, of 7 feet
+diameter and of 10<span class="enum">1</span>&#8725;<span class="denom">2</span> feet pitch, 135 revolutions a minute,
+giving the yacht a speed of 13<span class="enum">1</span>&#8725;<span class="denom">2</span> knots an hour.</p>
+
+<div class="figcenter"><a name="Fig136" id="Fig136"></a>
+<img src="images/illo416.png" alt="Horizontal Direct-Acting Naval Screw-Engine" width="550" height="319" />
+<p class="caption"><span class="smcap">Fig. 136.</span>&mdash;Horizontal, Direct-acting Naval Screw-Engine.</p></div>
+
+<p>In larger vessels, as in yachts, in nearly all cases, the
+ordinary screw-engine is direct-acting. Two engines are
+placed side by side, with cranks on the shaft at an angle
+of 90&deg; with each other. In merchant-steamers the
+steam-cylinders are usually vertical and directly over the
+crank-pins, to which the cross-heads are coupled. The condenser
+is placed behind the engine-frame, or, where a jet-condenser
+is used, the frame itself is sometimes made hollow,
+and serves as a condenser. The air-pump is worked by
+a beam connected by links with the cross-head. The general
+arrangement is like that shown in <a href="#Fig137">Figs. 137</a> and <a href="#Fig138">138</a>.
+For naval purposes such a form is objectionable, since its
+height is so great that it would be exposed to injury by
+shot. In naval engineering the cylinder is placed horizontally,
+as in <a href="#Fig136">Fig. 136</a>, which is a sectional view, representing
+an horizontal, direct-acting naval screw-engine, with jet-condenser
+and double-acting air and circulating pumps. <i>A</i>
+is the steam-cylinder, <i>B</i> the piston, which is connected to
+the crank-pin by the piston-rod, <i>D</i>, and connecting-rod, <i>E</i>.<span class='pagenum'><a
+name="Page_390" id="Page_390">[390]</a></span>
+<i>F</i> is the cross-head guide. The eccentrics, <i>G</i>, operate the
+valve, which is of the &#8220;three-ported variety,&#8221; by a Stephenson
+link. Reversing is effected by the hand-wheel, <i>C</i>,
+which, by means of a gear, <i>m</i>, and a rack, <i>k</i>, elevates and
+depresses the link, and thus reverses the valve.</p>
+
+<p>The trunk-engine, in which the connecting-rod is attached
+directly to the piston and vibrates within a trunk or
+cylinder secured to the piston, moving with it, and extending
+outside the cylinder, like an immense hollow piston-rod,
+is frequently used in the British navy. It has rarely
+been adopted in the United States.</p>
+
+<div class="figcenter"><a name="Fig137" id="Fig137"></a>
+<img src="images/illo417.png" alt="Compound Marine Engine, Side Elevation" width="350" height="481" />
+<p class="caption"><span class="smcap">Fig. 137.</span>&mdash;Compound Marine Engine. Side Elevation.</p></div>
+
+<div class="figcenter"><a name="Fig138" id="Fig138"></a>
+<img src="images/illo418.png" alt="Compound Marine Engine, Front Elevation and Section" width="350" height="411" />
+<p class="caption"><span class="smcap">Fig. 138.</span>&mdash;Compound Marine Engine. Front Elevation and Section.</p></div>
+
+<p><span class='pagenum'><a name="Page_391" id="Page_391">[391]</a></span>In nearly all steam-vessels which have been built for
+the merchant service recently, and in some naval vessels,
+the compound engine has been adopted. <a href="#Fig137">Figs. 137</a> and <a href="#Fig138">138</a>
+represent the usual form of this engine. Here <i>A A</i>, <i>B B</i>
+are the small and the large, or the high-pressure and the
+low-pressure cylinders respectively. <i>C C</i> are the valve-chests.
+<i>G G</i> is the condenser, which is invariably a surface-condenser.
+The condensing water is sometimes directed
+around the tubes contained within the casing, <i>G G</i>,
+while the steam is exhausted around them and among them,<span class='pagenum'><a name="Page_392" id="Page_392">[392]</a></span>
+and sometimes the steam is condensed within the tubes,
+while the injection-water which is sent into the condenser
+to produce condensation passes around the exterior of the
+tubes. In either case, the tubes are usually of small diameter,
+varying from five-eighths to half an inch, and in length
+from four to seven feet. The extent of heating-surface is
+usually from one-half to three-fourths that of the heating-surface
+of the boilers.</p>
+
+<p>The air and circulating pumps are placed on the lower
+part of the condenser-casting, and are operated by a crank
+on the main shaft at <i>N</i>; or they are sometimes placed as
+in the style of engine last described, and driven by a beam
+worked by the cross-head. The piston-rods, <i>T S</i>, are guided
+by the cross-heads, <i>V V</i>, working in slipper-guides, and to
+these cross-heads are attached the connecting-rods, <i>X X</i>,
+driving the cranks, <i>M M</i>. The cranks are now usually set
+at right angles; in some engines this angle is increased to
+120&deg;, or even 180&deg;. Where it is arranged as here shown,
+an intermediate reservoir, <i>P O</i>, is placed between the two
+cylinders to prevent the excessive variations of pressure
+that would otherwise accompany the varying relative motions
+of the pistons, as the steam passes from the high-pressure
+to the low-pressure cylinder. Steam from the
+boilers enters the high-pressure steam-chest, <i>x</i>, and is admitted
+by the steam-valve alternately above and below the
+piston as usual. The exhaust steam is conducted through
+the exhaust passage around into the reservoir, <i>P</i>, whence it
+it is taken by the low-pressure cylinder, precisely as the
+smaller cylinder drew its steam from the boiler. From the
+large or low-pressure cylinder the steam is exhausted into
+the condenser. The valve-gear is usually a Stephenson
+link, <i>g e</i>, the position of which is determined, and the reversal
+of which is accomplished, by a hand-wheel, <i>o</i>, and
+screw, <i>m n p</i>, which, by the bell-crank, <i>k i</i>, are attached to
+the link, <i>g e</i>. The &#8220;box-framing&#8221; forms also the hot-well.
+The surface-condenser is cleared by a single-acting air-pump,<span class='pagenum'><a name="Page_393" id="Page_393">[393]</a></span>
+inside the frame, at <i>T</i>. The feed-pump and the bilge-pumps
+are driven from the cross-head of the air-pump.</p>
+
+<div class="figcenter"><a name="Port12" id="Port12"></a>
+<img src="images/illo420.png" alt="Elder" width="350" height="417" />
+<p class="caption">John Elder.</p></div>
+
+<p>The successful introduction of the double-cylinder engine
+was finally accomplished by the exertions of a few
+engineers, who were at once intelligent enough to understand
+its advantages, and energetic and enterprising enough
+to push it forward in spite of active opposition, and powerful
+enough, pecuniarily and in influence, to succeed.
+The most active and earnest of these eminent men was
+<a href="#Port12">John Elder</a>, of the firm of Randolph, Elder &amp; Co., subsequently
+John Elder &amp; Co., of Glasgow.<a name="FNanchor_97_97" id="FNanchor_97_97"></a><a href="#Footnote_97_97" class="fnanchor">[97]</a></p>
+
+<p>Elder was of Scotch descent. His ancestors had, for<span class='pagenum'><a name="Page_394" id="Page_394">[394]</a></span>
+generations, shown great skill and talent in construction,
+and had always been known as successful millwrights. John
+Elder was born at Glasgow, March 8, 1824, and died in
+London, September 17, 1869. He was educated at the
+Glasgow High-School and in the College of Engineering at
+the University of Glasgow, where, however, his attendance
+was but for a short time. He learned the trade under his
+father in the workshops of the Messrs. Napier, and became
+an unusually expert draughtsman. After spending three
+years in charge of the drawing-office at the engine-building
+works of Robert Napier, where his father had been manager,
+Elder became a partner in the firm which had previously
+been known as Randolph, Elliott &amp; Co., in the year 1852.
+The firm commenced building iron vessels in 1860.</p>
+
+<p>In the mean time, the experiments of Hornblower and
+Wolff, of Allaire and Smith, and of McNaught, Craddock,
+and Nicholson, together with the theoretical investigations
+of Thompson, Rankine, Clausius, and others, had shown
+plainly in what direction to look for improvement upon
+then standard engines, and what direction practice was
+taking with all types. The practical deductions which were
+becoming evident were recognized very early by Elder, and
+he promptly began to put in practice the principles which
+his knowledge of thermo-dynamics and of mechanics enabled
+him to appreciate. He adopted the compound engine,
+and coupled his cranks at angles of 180&deg;, in order to avoid
+losses due to the friction of the crank-shaft in its bearings,
+by effecting a partial counterbalancing of pressures on the
+journals. Elder was one of the first to point out the fact that
+the compound engine had proved itself more efficient than
+the single-cylinder engine, only when the pressure of steam
+carried and the extent to which expansion was adopted exceeded
+the customary practice of his time. His own practice
+was, from the first, successful, and from 1853 to 1867 he
+and his partners were continually engaged in the construction
+of steamers and fitting them with compound engines.</p>
+
+<p><span class='pagenum'><a name="Page_395" id="Page_395">[395]</a></span>The engines of their first vessel, the Brandon, required
+but 3<span class="enum">1</span>&#8725;<span class="denom">4</span> pounds of coal per hour and per horse-power, in
+1854, when the usual consumption was a third more. Five
+years later, they had built engines which consumed a third
+less than those of the Brandon; and thenceforward, for
+many years, their engines, when of large size, exhibited
+what was then thought remarkable economy, running on a
+consumption of from 2<span class="enum">1</span>&#8725;<span class="denom">4</span> to
+2<span class="enum">1</span>&#8725;<span class="denom">2</span> pounds.</p>
+
+<p>In the year 1865 the British Government ordered a
+competitive trial of three naval vessels, which only differed
+in the form of their engines. The Arethusa was
+fitted with trunk-engines of the ordinary kind; the Octavia
+had three steam-cylinders, coupled to three cranks placed
+at angles of 120&deg; with each other; and the Constance was
+fitted with compound engines, two sets of three cylinders
+each, and each taking steam from the boiler into one cylinder,
+passing it through the other two with continuous expansion,
+and finally exhausting from the third into the condenser.
+These vessels, during one week&#8217;s steaming at sea,
+averaged, respectively, 3.64, 3.17, and 2.51 pounds of coal
+per hour and per horse-power, and the Constance showed a
+marked superiority in the efficiency of the mechanism of
+her engines, when the losses by friction were compared.</p>
+
+<p>The change from the side-lever single-cylinder engine,
+with jet-condenser and paddle-wheels, to the direct-acting
+compound engine, with surface-condenser and screw-propellers,
+has occurred within the memory and under the observation
+of even young engineers, and it may be considered
+that the revolution has not been completely effected. This
+change in the design of engine is not as great as it at first
+seemed likely to become. Builders have but slowly learned
+the principles stated above in reference to expansion in one
+or more cylinders, and the earlier engines were made with
+a high and low pressure cylinder working on the same connecting-rod,
+and each machine consisted of four steam-cylinders.
+It was at last discovered that a high-pressure single-cylinder<span class='pagenum'><a name="Page_396" id="Page_396">[396]</a></span>
+engine exhausting into a separate larger low-pressure
+engine might give good results, and the compound
+engine became as simple as the type of engine which it
+displaced. This independence of high and low pressure engines
+is not in itself novel, for the plan of using the exhaust
+of a high-pressure engine to drive a low-pressure condensing
+engine was one of the earliest of known combinations.</p>
+
+<p>The advantage of introducing double engines at sea is
+considerably greater than on land. The coal carried by a
+steam-vessel is not only an item of great importance in consequence
+of its first cost, but, displacing its weight or bulk
+of freight which might otherwise be carried, it represents so
+much non-paying cargo, and is to be charged with the full
+cost of transportation in addition to first cost. The best of
+steam-coal is therefore usually chosen for steamers making
+long voyages, and the necessity of obtaining the most economical
+engines is at once seen, and is fully appreciated by
+steamship proprietors. Again, an economy of one-fourth of
+a pound per horse-power per hour gives, on a large transatlantic
+steamer, a saving of about 100 tons of coal for a
+single voyage. To this saving of cost is to be added the
+gain in wages and sustenance of the labor required to handle
+that coal, and the gain by 100 tons of freight carried in
+place of the coal.</p>
+
+<p>For many years the change which has here been outlined,
+in the forms of engine and the working of steam expansively,
+was retarded by the inefficiency of methods and
+tools used in construction. With gradual improvement in
+tools and in methods of doing work, it became possible to
+control higher steam and to work it successfully; and the
+change in this direction has been steadily going on up to
+the present time with all types of steam-engine. At sea
+this rise of pressure was for a considerable time retarded
+by the serious difficulty encountered in the tendency of the
+sulphate of lime to deposit in the boiler. When steam-pressure
+had risen to 25 pounds per square inch, it was<span class='pagenum'><a name="Page_397" id="Page_397">[397]</a></span>
+found that no amount of &#8220;blowing out&#8221; would prevent the
+deposition of seriously large quantities of this salt, while at
+the lower pressures at first carried at sea no troublesome
+precipitation occurred, and the only precaution necessary
+was to blow out sufficient brine to prevent the precipitation
+of common salt from a supersaturated solution. The
+introduction of surface-condensation was promptly attempted
+as the remedy for this evil, but for many years
+it was extremely doubtful whether its disadvantages were
+not greater than its advantages. It was found very difficult
+to keep the condensers tight, and boilers were injured
+by some singular process of corrosion, evidently due to the
+presence of the surface-condenser. The simple expedient
+of permitting a very thin scale to form in the boiler was,
+after a time, hit upon as a means of overcoming this difficulty,
+and thenceforward the greatest obstacle to the general
+introduction was the conservative disposition found
+among those who had charge of marine machinery, which
+conservatism regarded with suspicion every innovation.
+Another trouble arose from the difficulty of finding men
+neither too indolent nor too ignorant to take charge of the
+new condenser, which, more complicated and more readily
+disarranged than the old, demanded a higher class of attendants.
+Once introduced, however, the surface-condenser
+removed the obstacle to further elevation of steam-pressure,
+and the rise from 20 to 60 pounds pressure soon occurred.
+Elder and his competitors on the Clyde were the first to
+take advantage of the fact when these higher pressures became
+practicable.</p>
+
+<p>The lightness of engine and the smaller weight of boiler
+secured when the simpler type of &#8220;compound&#8221; engine is
+used are great advantages, and, when coupled with the
+fact that by no other satisfactory device can great expansion
+and consequent economy of fuel be obtained at sea,
+the advantages are such as to make the adoption of this
+style of engine imperative for ship-propulsion.</p>
+
+<p><span class='pagenum'><a name="Page_398" id="Page_398">[398]</a></span>This extreme lightness in machinery has been largely,
+also, the result of very careful and skillful designing, of
+intelligent construction, and of care in the selection and
+use of material. British builders had, until after the introduction
+of these later types of vessels-of-war, been distinguished
+rather by the weight of their machinery than for
+nice calculation and proportioning of parts. Now the engines
+of the heavy iron-clads are models of good proportions,
+excellence in materials, and of workmanship, which
+are well worthy of study. The weight per indicated horse-power
+has been reduced from 400 or 500 pounds to less
+than half that amount within the last ten years. This has
+been accomplished by forcing the boilers&mdash;although thus,
+to some extent, losing economy&mdash;by higher steam-pressure,
+a very much higher piston-speed, reduction of friction of
+parts, reduction of capacity for coal-stowage, and exceedingly
+careful proportioning. The reduction of coal-bunker
+capacity is largely compensated by the increase of economy
+secured by superheating, by increased expansion, elevation
+of piston-speed, and the introduction of surface-condensation.</p>
+
+<p>A good marine steam-engine of the form which was
+considered standard 15 or 20 years ago, having low-pressure
+boilers carrying steam at 20 or 25 pounds pressure as
+a maximum, expanding twice or three times, and having a
+jet-condenser, would require about 30 or 35 pounds of feed-water
+per horse-power per hour; substituting surface-condensation
+for that produced by the jet brought down the
+weight of steam used to from 25 to 30 pounds; increasing
+steam-pressure to 60 pounds, expanding from five to eight
+times, and combining the special advantages of the superheater
+and the compound engine with surface-condensation,
+has reduced the consumption of steam to 20, or even, in
+some cases, 15 pounds of steam per horse-power per hour.
+Messrs. Perkins, of London, guarantee, as has already
+been stated, to furnish engines capable of giving a horse-power
+with a consumption of but 1<span class="enum">1</span>&#8725;<span class="denom">4</span> pound of coal. Mr.<span class='pagenum'><a name="Page_399" id="Page_399">[399]</a></span>
+C. E. Emery reports the United States revenue-steamer
+Hassler, designed by him, to have given an ordinary sea-going
+performance which is probably fully equal to anything
+yet accomplished. The Hassler is a small steamer, of
+but 151 feet in length, 24<span class="enum">1</span>&#8725;<span class="denom">2</span> feet beam, and 10 feet draught.
+The engines have steam-cylinders 18.1 and 28 inches diameter,
+respectively, and of 28 inches stroke of piston, indicating
+125 horse-power; with steam at 75 pounds pressure,
+and at a speed of but 7 knots, the coal consumed was but
+1.87 pound per horse-power per hour.</p>
+
+<p>The committee of the British Admiralty on designs of
+ships-of-war have reported recently: &#8220;The carrying-power
+of ships may certainly be to some extent increased by the
+adoption of compound engines in her Majesty&#8217;s service.
+Its use has recently become very general in the mercantile
+marine, and the weight of evidence in favor of the large
+economy of fuel thereby gained is, to our minds, overwhelming
+and conclusive. We therefore beg earnestly to
+recommend that the use of compound engines may be generally
+adopted in ships-of-war hereafter to be constructed,
+and applied, whenever it can be done with due regard to
+economy and to the convenience of the service, to those
+already built.&#8221;</p>
+
+<p>The forms of screws now employed are exceedingly
+diverse, but those in common use are not numerous. In
+naval vessels it is common to apply screws of two blades,
+that they may be hoisted above water into a &#8220;well&#8221; when
+the vessel is under sail, or set with the two blades directly
+behind the stern-post, when their resistance to the forward
+motion of the vessel will be comparatively small. In other
+vessels, and in the greater number of full-power naval vessels,
+screws of three or four blades are used.</p>
+
+<div class="figcenter"><a name="Fig139" id="Fig139">
+</a><img src="images/illo427.png" alt="Screw-Propeller" width="500" height="499" />
+<p class="caption"><span class="smcap">Fig. 139.</span>&mdash;Screw-Propeller.</p></div>
+
+<p>The usual form of screw (<a href="#Fig139">Fig. 139</a>) has blades of nearly
+equal breadth from the hub to the periphery, or slightly
+widening toward their extremities, as is seen in an exaggerated
+degree in <a href="#Fig140">Fig. 140</a>, representing the form adopted
+for<span class='pagenum'><a name="Page_400" id="Page_400">[400]</a></span>
+tug-boats, where large surface near the extremity is more
+generally used than in vessels of high speed running free.
+In the Griffith screw, which has been much used, the hub
+is globular and very large. The blades are secured to the
+hub by flanges, and are bolted on in such a manner that
+their position may be changed slightly if desired. The
+blades are shaped like the section of a pear, the wider part
+being nearest the hub, and the blades tapering rapidly
+toward their extremities. A usual form is intermediate
+between the last, and is like that shown in <a href="#Fig141">Fig. 141</a>, the
+hub being sufficiently enlarged to permit the blades to be
+attached as in the Griffith screw, but more nearly cylindrical,
+and the blades having nearly uniform width from end
+to end.</p>
+
+<div class="figcenter"><a name="Fig140" id="Fig140"></a>
+<img src="images/illo428a.png" alt="Tug-Boat Screw" width="269" height="350" />
+<p class="caption"><span class="smcap">Fig. 140.</span>&mdash;Tug-boat Screw.</p></div>
+
+<p><span class='pagenum'><a name="Page_401" id="Page_401">[401]</a></span>The pitch of a screw is the distance which would be
+traversed by the screw in one revolution were it to move
+through the water without slip; i. e., it is double the distance
+<i>C D</i>, <a href="#Fig140">Fig. 140</a>. <i>C D&#8242;</i> represents the helical path of
+the extremity of the blade <i>B</i>, and <i>O E F H K</i> is that of
+the blade <i>A</i>. The proportion of diameter to the pitch of
+the screw is determined by the speed of the vessel. For
+low speed the pitch may be as small as 1<span class="enum">1</span>&#8725;<span class="denom">4</span> the diameter.
+For vessels of high speed the pitch is frequently double the
+diameter. The diameter of the screw is made as great as
+possible, since the slip decreases with the increase of the
+area of screw-disk. Its length is usually about one-sixth of
+the diameter. A greater length produces loss by increase
+of surface causing too great friction, while a shorter screw
+does not fully utilize the resisting power of the cylinder of
+water within which it works, and increased slip causes
+waste of power. An empirical value for the probable slip
+in vessels of good shape, which is closely approximate usually,
+is <i>S</i> = 4<i>M</i>&#8725;<i>A</i>,
+in which <i>S</i> is the slip per cent., and <i>M</i> and
+<i>A</i> are the areas of the midship section and of the screw-disk
+in square feet.</p>
+
+<div class="figcenter"><a name="Fig141" id="Fig141"></a>
+<img src="images/illo428b.png" alt="Hirsch Screw" width="350" height="333" />
+<p class="caption"><span class="smcap">Fig. 141.</span>&mdash;Hirsch Screw.</p></div>
+
+<p><span class='pagenum'><a name="Page_402" id="Page_402">[402]</a></span>The most effective screws have slightly greater pitch at
+the periphery than at the hub, and an increasing pitch from
+the forward to the rear part of the screw. The latter
+method of increasing pitch is more generally adopted alone.
+The thrust of the screw is the pressure which it exerts in
+driving the vessel forward. In well-formed vessels, with
+good screws, about two-thirds of the power applied to the
+screw is utilized in propulsion, the remainder being wasted
+in slip and other useless work. Its efficiency is in such a
+case, therefore, 66 per cent. Twin screws, one on each side
+of the stern-post, are sometimes used in vessels of light
+draught and considerable breadth, whereby decreased slip
+is secured.</p>
+
+<p>As has already been stated, the introduction of the compound
+engine has been attempted, but with less success
+than in Europe, by several American engineers.</p>
+
+<p>The most radical change in the methods of ship-propulsion
+which has been successfully introduced in some localities
+has been the adoption of a system of &#8220;wire-rope towage.&#8221;
+It is only well adapted for cases in which the steamer
+traverses the same line constantly, moving backward and
+forward between certain points, and is never compelled to
+deviate to any considerable extent from the path selected.
+A similar system is in use in Canada, but it has not yet
+come into use in the United States, notwithstanding the
+fact that, wherever its adoption is practicable, it has a
+marked superiority in economy over the usual methods of
+propulsion. With chain or rope traction there is no loss by
+slip or oblique action, as in both screw and paddle-wheel
+propulsion. In the latter methods these losses amount to
+an important fraction of the total power; they rarely, if
+ever, fall below a total of 25 per cent., and probably in
+towage exceed 50 per cent. The objection to the adoption
+of chain-propulsion, as it is also often called, is the necessity
+of following closely the line along which the chain or the
+rope is laid. There is, however, much less difficulty than<span class='pagenum'><a name="Page_403" id="Page_403">[403]</a></span>
+would be anticipated in following a sinuous route or in
+avoiding obstacles in the channel or passing other vessels.
+The system is particularly well adapted for use on canals.</p>
+
+<p>The steam-boilers in use in the later and best marine
+engineering practice are of various forms, but the standard
+types are few in number. That used on river-steamers in
+the United States has already been described.</p>
+
+<div class="figcenter"><a name="Fig142" id="Fig142"></a>
+<img src="images/illo430.png" alt="Marine Fire-Tubular Boiler, Section" width="350" height="313" />
+<p class="caption"><span class="smcap">Fig. 142.</span>&mdash;Marine Fire-tubular Boiler. Section.</p></div>
+
+<p><a href="#Fig142">Fig. 142</a> is a type of marine tubular boiler which is in
+most extensive use in sea-going steamers for moderate
+pressure, and particularly for naval vessels. Here the gases
+pass directly into the back connection from the fire, and
+thence forward again, through horizontal tubes, to the front
+connection and up the chimney. In naval vessels the steam-chimney
+is omitted, as it is there necessary to keep all parts
+of the boiler as far below the water-line as possible. Steam
+is taken from the boiler by pipes which are carried from
+end to end of the steam-space, near the top of the boiler,
+the steam entering these pipes through small holes drilled
+on the other side. Steam is thus taken from the boiler
+&#8220;wet,&#8221; but no large quantity of water can usually be &#8220;entrained&#8221;
+by the steam.</p>
+
+<p>A marine boiler has been quite extensively introduced<span class='pagenum'><a name="Page_404" id="Page_404">[404]</a></span>
+into the United States navy, in which the gases are led
+from the back connection through a tube-box around and
+among a set of upright water-tubes, which are filled with
+water, circulation taking place freely from the water-space
+immediately above the crown-sheet of the furnace up
+through these tubes into the water-space above them.
+These &#8220;water-tubular&#8221; boilers have a slight advantage
+over the &#8220;fire-tubular&#8221; boilers already described in compactness,
+in steaming capacity, and in economical efficiency.
+They have a very marked advantage in the facility with
+which the tubes may be scraped or freed from the deposit
+when a scale of sulphate of lime or other salt has formed
+within them by precipitation from the water. The fire-tubular
+boiler excels in convenience of access for plugging
+up leaking tubes, and is much less costly than the water-tubular.
+The water-tube class of boilers still remain in
+extensive use in the United States naval steamers. They
+have never been much used in the merchant service, although
+introduced by James Montgomery in the United
+States and by Lord Dundonald in Great Britain twenty
+years earlier. Opinion still remains divided among engineers
+in regard to their relative value. They are gradually
+reassuming prominence by their introduction in the modified
+form of sectional boilers.</p>
+
+<div class="figcenter"><a name="Fig143" id="Fig143"></a>
+<img src="images/illo431.png" alt="Marine High-Pressure Boiler, Section" width="350" height="254" />
+<p class="caption"><span class="smcap">Fig. 143.</span>&mdash;Marine High-Pressure Boiler. Section.</p></div>
+
+<p>Marine boilers are now usually given the form shown in
+section in <a href="#Fig143">Fig. 143</a>. This form of
+boiler is adopted where<span class='pagenum'><a name="Page_405" id="Page_405">[405]</a></span>
+steam-pressures of 60 pounds and upward are carried, as in
+steam-vessels supplied with compound engines, cylindrical
+forms being considered the best with high pressures. The
+large cylindrical flues, therefore, form the furnaces as
+shown in the transverse sectional view. The gases rise, as
+shown in the longitudinal section, through the connection,
+and pass back to the end of the boiler through the tubes,
+and thence, instead of entering a steam-chimney, they are
+conducted by a smoke-connection, not shown in the sketch,
+to the smoke funnel or stack. In merchant-steamers, a
+steam-drum is often mounted horizontally above the boiler.
+In other cases a separator is attached to the steam-pipe
+between boilers and engines. This usually consists of an
+iron tank, divided by a vertical partition extending from the
+top nearly to the bottom. The steam, entering the top at
+one side of this partition, passes underneath it, and up to
+the top on the opposite side, where it issues into a steam-pipe
+leading directly to the engine. The sudden reversal
+of its course at the bottom causes it to leave the suspended
+water in the bottom of the separator, whence it is drained
+off by pipes.</p>
+
+<p>The most interesting illustrations of recent practice in
+marine engineering and naval architecture are found in the
+steamers which are now seen on transoceanic routes for the
+merchant service, and, in the naval service, in the enormous
+iron-clads which have been built in Great Britain.</p>
+
+<p>The City of Peking is one of the finest examples of
+American practice. This vessel was constructed for the
+Pacific Mail Company. The hull is 423 feet long, of 48
+feet beam, and 38<span class="enum">1</span>&#8725;<span class="denom">2</span> feet deep. Accommodations are furnished
+for 150 cabin and 1,800 steerage passengers, and the
+coal-bunkers &#8220;stow&#8221; 1,500 tons of coal. The iron plates
+of which the sides and bottom are made are from <span class="enum">11</span>&#8725;<span class="denom">16</span> to one
+inch in thickness. The weight of iron used in construction
+was about 5,500,000 pounds. The machinery weighed nearly
+2,000,000 pounds, with spare gear and accessory apparatus.<span class='pagenum'><a name="Page_406" id="Page_406">[406]</a></span>
+The engines are compound, with two steam-cylinders of
+51 inches and two of 88 inches diameter, and a stroke of
+piston of 4<span class="enum">1</span>&#8725;<span class="denom">2</span> feet. The condensing water is sent through
+the surface-condensers by circulating-pumps driven by their
+own engines. Ten boilers furnish steam to these engines,
+each having a diameter of 13 feet, a length of 13<span class="enum">1</span>&#8725;<span class="denom">2</span> feet, and
+a thickness of &#8220;shell&#8221; of 1<span class="enum">3</span>&#8725;<span class="denom">16</span> inch. Each has three furnaces,
+and contains 204 tubes of an outside diameter of 3<span class="enum">1</span>&#8725;<span class="denom">4</span> inches.
+All together, they have 520 square feet of grate-surface and
+17,000 square feet of heating-surface. The area of cooling-surface
+in the condensers is 10,000 square feet. The City
+of Rome, a ship of later design, is 590 feet long, &#8220;over all,&#8221;
+52 feet beam, 52 feet deep, and measures 8,300 tons. The
+engines, of 8,500 horse-power, will drive the vessel 18 knots
+(21 miles) an hour; they have six steam-cylinders (three
+high and three low pressure), and are supplied with steam
+by 8 boilers heated by 48 furnaces. The hull is of steel, the
+bottom double, and the whole divided into ten compartments
+by transverse bulkheads. Two longitudinal bulkheads
+in the engine and boiler compartments add greatly to the
+safety of the vessel.</p>
+
+<p>The most successful steam-vessels in general use are these
+screw-steamers of transoceanic lines. Those of the transatlantic
+lines are now built from 350 to 550 feet long, generally
+propelled from 12 to 18 knots (14 to 21 miles) an hour,
+by engines of from 3,000 to 8,000 horse-power, consuming
+from 70 to 250 tons of coal a day, and crossing the Atlantic
+in from eight to ten days. These vessels are now invariably
+fitted with the compound engine and surface-condensers.
+One of these vessels, the Germanic, has been reported at
+Sandy Hook, the entrance to New York Harbor, in 7 days 11
+hours 37 minutes from Queenstown&mdash;a distance, as measured
+by the log and by observation, of 2,830 miles. Another
+steamer, the Britannic, has crossed the Atlantic in 7 days 10
+hours and 53 minutes. These vessels are of 5,000 tons burden,
+of 750 &#8220;nominal&#8221; horse-power (probably 5,000 actual).</p>
+
+<div class="figcenter"><a name="Fig144" id="Fig144"></a>
+<img src="images/illo434.png" alt="The Modern Steamship" width="474" height="275" />
+<p class="caption"><span class="smcap">Fig. 144.</span>&mdash;The Modern Steamship.</p></div>
+
+<p><span class='pagenum'><a name="Page_407" id="Page_407">[407-408]</a></span>The <a href="#Fig144">modern steamship</a>
+is as wonderful an illustration of
+ingenuity and skill in all interior arrangements as in size,<span class='pagenum'><a name="Page_408" id="Page_408"></a></span>
+power, and speed. The size of sea-going steamers has become
+so great that it is unsafe to intrust the raising of the anchor
+or the steering of the vessel to manual power and skill; and
+these operations, as well as the loading and unloading of the
+vessel, are now the work of the same great motor&mdash;steam.</p>
+
+<p>The now common form of auxiliary engine for controlling
+the helm is one of the inventions of the American engineer
+F. E. Sickels, who devised the &#8220;Sickels cut-off,&#8221; and
+was first invented about 1850. It was exhibited at London
+at the International Exhibition of 1851. It consists<a name="FNanchor_98_98" id="FNanchor_98_98"></a><a
+href="#Footnote_98_98" class="fnanchor">[98]</a> principally
+of two cylinders working at right angles upon a shaft
+geared into a large wheel fastened by a friction-plate lined
+with wood, and set by a screw to any desired pressure on
+the steering-apparatus. The wheel turned by the steersman
+is connected with the valve-gear of the cylinders, so
+that the steam, or other motor, will move the rudder precisely
+as the helmsman moves the wheel adjusting the
+steam-valves. This wheel thus becomes the steering-wheel.
+The apparatus is usually so arranged that it may be connected
+or disconnected in an instant, and hand-steering
+adopted if the smoothness of the sea and the low speed of
+the vessel make it desirable or convenient. This method
+was first adopted in the United States on the steamship
+Augusta.</p>
+
+<p>The same inventor and others have contrived &#8220;steam-windlasses,&#8221;
+some of which are in general use on large vessels.
+The machinery of these vessels is also often fitted
+with a steam &#8220;reversing-gear,&#8221; by means of which the engines
+are as easily man&oelig;uvred as are those of the smallest
+vessels, to which hand-gear is always fitted. In one of these
+little auxiliary engines, as devised by the author, a small
+handle being adjusted to a marked position, as to the point
+marked &#8220;stop&#8221; on an index-plate, the auxiliary engine at
+once starts, throws the valve-gear into the proper position&mdash;as,<span class='pagenum'><a name="Page_409" id="Page_409">[409]</a></span>
+if a link-motion, into &#8220;middle-gear&#8221;&mdash;thus stopping the
+large engines, and then it itself stops. Setting the handle
+so that its pointer shall point to &#8220;ahead,&#8221; the little engine
+starts again, sets the link in position to go ahead, thus
+starting the large engines, and again stops itself. If set at
+&#8220;back,&#8221; the same series of operations occurs, leaving the
+main engines backing and the little &#8220;reversing engine&#8221;
+stopped. A number of forms of reversing engine are in
+use, each adapted to some one type of engine.</p>
+
+<p>The hull of the transatlantic steamer is now always of
+iron, and is divided into a number of &#8220;compartments,&#8221; each
+of which is water-tight and separated from the adjacent
+compartments by iron &#8220;bulkheads,&#8221; in which are fitted
+doors which, when closed, are also water-tight. In some
+cases these doors close automatically when the water rises
+in the vessel, thus confining it to the leaking portion.</p>
+
+<p>Thus we have already seen a change in transoceanic
+lines from steamers like the Great Western (1837), 212 feet
+in length, of 35<span class="enum">1</span>&#8725;<span class="denom">2</span> feet beam, and 23 feet depth, driven by
+engines of 450 horse-power, and requiring 15 days to cross
+the Atlantic, to steamships over 550 feet long, 55 feet beam,
+and 55 feet deep, with engines of 10,000 horse-power, crossing
+the Atlantic in 7 days; iron substituted for wood in
+construction, the cost of fuel reduced one-half, and the
+speed raised from 8 to 18 knots and over. In the earlier
+days of steamships they were given a proportion of length
+to breadth of from 5 to 6 to 1; in forty years the proportion
+increased until 11 to 1 was reached.</p>
+
+<p>The whole naval establishment of every country has
+been greatly modified by the recent changes in methods of
+attack and defense; but the several classes of ships which
+still form the naval marine are all as dependent upon their
+steam-machinery as ever.</p>
+
+<table style="width: 500px;" summary="Fig. 145">
+
+<tr>
+<td colspan="4" class="figcenter"><a name="Fig145" id="Fig145"></a>
+<img src="images/illo437.png" alt="Modern Iron-Clads" width="474" height="275" /></td>
+</tr>
+
+<tr>
+<td class="center fsize80">H. B. M. Iron-Clad Captain.</td>
+<td class="center fsize80">H. B. M. Iron-Clad Thunderer.</td>
+<td class="center fsize80">U. S. Iron-Clad Dictator.</td>
+<td class="center fsize80">U. S. Iron-Clad Monitor.</td>
+</tr>
+
+<tr>
+<td colspan="4" style="line-height: .5em;">&nbsp;</td>
+</tr>
+
+<tr>
+<td colspan="2" class="center fsize80">H. B. M. Iron-Clad Giatton.</td>
+<td colspan="2" class="center fsize80">French Iron-Clad Dunderberg.</td>
+</tr>
+
+</table>
+
+<p class="caption"><span class="smcap">Fig. 145.</span>&mdash;Modern Iron-Clads.</p>
+
+<p>It is only recently that the attempt seems to have been
+made to determine a classification of war-vessels and to
+plan a naval establishment which shall be likely to meet<span class='pagenum'><a name="Page_410" id="Page_410">[410]</a></span>
+fully the requirements of the immediate future. It has
+hitherto been customary simply to make each ship a little
+stronger, faster, or more powerful to resist or to make<span class='pagenum'><a name="Page_411" id="Page_411">[411]</a></span>
+attack than was the last. The fact that the direction of
+progress in naval science and architecture is plainly perceivable,
+and that upon its study may be based a fair estimate
+of the character and relative distribution of several classes
+of vessels, seems to have been appreciated by very few.</p>
+
+<p>In the year 1870 the writer proposed<a name="FNanchor_99_99" id="FNanchor_99_99"></a><a
+href="#Footnote_99_99" class="fnanchor">[99]</a> a classification of
+vessels other than torpedo-vessels, which has since been also
+proposed in a somewhat modified form by Mr. J. Scott
+Russell.<a name="FNanchor_100_100" id="FNanchor_100_100"></a><a href="#Footnote_100_100" class="fnanchor">[100]</a>
+The author then remarked that the increase so
+rapidly occurring in weight of ordnance and of armor, and
+in speed of war-vessels, would probably soon compel a division
+of the vessels of every navy into three classes of
+ships, exclusive of torpedo-vessels, one for general service
+in time of peace, the others for use only in time of war.</p>
+
+<p>&#8220;The first class may consist of unarmored vessels of
+moderate size, fair speed under steam, armed with a few
+tolerably heavy guns, and carrying full sail-power.</p>
+
+<p>&#8220;The second class may be vessels of great speed under
+steam, unarmored, carrying light batteries and as great
+spread of canvas as can readily be given them; very much
+such vessels as the Wampanoag class of our own navy were
+intended to be&mdash;calculated expressly to destroy the commerce
+of an enemy.</p>
+
+<p>&#8220;The third class may consist of ships carrying the
+heaviest possible armor and armament, with strongly-built
+bows, the most powerful machinery that can be given them,
+of large coal-carrying capacity, and unencumbered by sails,
+everything being made secondary to the one object of obtaining
+victory in contending with the most powerful of
+possible opponents. Such vessels could never go to sea
+singly, but would cruise in couples or in squadrons. It
+seems hardly doubtful that attempts to combine the qualities
+of all classes in a single vessel, as has hitherto been<span class='pagenum'><a name="Page_412" id="Page_412">[412]</a></span>
+done, will be necessarily given up, although the classification
+indicated will certainly tend largely to restrict naval
+operations.&#8221;</p>
+
+<p>The introduction of the stationary, the floating, and the
+automatic classes of torpedoes, and of torpedo-vessels, has
+now become accomplished, and this element, which it was
+predicted by Bushnell and by Fulton three-quarters of a
+century ago would at some future time become important
+in warfare, is now well recognized by all nations. How far
+it may modify future naval establishments cannot be yet
+confidently stated, but it seems sufficiently evident that the
+attack, by any navy, of stationary defenses protected by
+torpedoes is now quite a thing of the past. It may be perhaps
+looked upon as exceedingly probable that torpedo-ships
+of very high speed will yet drive all heavily-armored
+vessels from the ocean, thus completing the historic parallel
+between the man-in-armor of the middle ages and the armored
+man-of-war of our own time.<a name="FNanchor_101_101" id="FNanchor_101_101"></a><a href="#Footnote_101_101" class="fnanchor">[101]</a></p>
+
+<p>Of these classes, the third is of most interest, as exhibiting
+most perfectly the importance and variety of the work
+which the steam-engine is made to perform. On the later
+of these vessels, the anchor is raised by a steam anchor-hoisting
+apparatus; the heavier spars and sails are handled
+by the aid of a steam-windlass; the helm is controlled by a
+steering-engine, and the helmsman, with his little finger,
+sets in motion a steam-engine, which adjusts the rudder
+with a power which is unimpeded by wind or sea, and with
+an exactness that could not be exceeded by the hand-steering
+gear of a yacht; the guns are loaded by steam, are elevated
+or depressed, and are given lateral training, by the
+same power; the turrets in which the guns are incased are
+turned, and the guns are whirled toward every point of the
+compass, in less time than is required to sponge and reload<span class='pagenum'><a name="Page_413" id="Page_413">[413]</a></span>
+them; and the ship itself is driven through the water by
+the power of ten thousand horses, at a speed which is only
+excelled on land by that of the railroad-train.</p>
+
+<p>The British Minotaur was one of the earlier iron-clads.
+The great length and consequent difficulty of man&oelig;uvring,
+the defect of speed, and the weakness of armor of these
+vessels have led to the substitution of far more effective
+designs in later constructions. The Minotaur is a four-masted
+screw iron-clad, 400 feet long, of 59 feet beam and
+26<span class="enum">1</span>&#8725;<span class="denom">2</span> feet draught of water.
+Her speed at sea is about 12<span class="enum">1</span>&#8725;<span class="denom">2</span>
+knots, and her engines develop, as a maximum, nearly 6,000
+indicated horse-power. Her heaviest armor-plates are but
+6 inches in thickness. Her extreme length and her unbalanced
+rudder make it difficult to turn rapidly. With <i>eighteen
+men at the steering-wheel</i> and sixty others on the tackle,
+the ship, on one occasion, was 7<span class="enum">1</span>&#8725;<span class="denom">2</span> minutes in turning completely
+around. These long iron-clads were succeeded by
+the shorter vessels designed by Mr. E. J. Reed, of which
+the first, the Bellerophon, was of 4,246 tons burden, 300
+feet long by 56 feet beam, and 24<span class="enum">1</span>&#8725;<span class="denom">2</span> feet draught, of the 14-knot
+speed, with 4,600 horse-power; and having the &#8220;balanced
+rudder&#8221; used many years earlier in the United States
+by Robert L. Stevens,<a name="FNanchor_102_102" id="FNanchor_102_102"></a><a
+href="#Footnote_102_102" class="fnanchor">[102]</a> it can turn in four minutes with
+eight men at the wheel. The cost of construction was some
+$600,000 less than that of the Minotaur. A still later vessel,
+the Monarch, was constructed on a system quite similar
+to that known in the United States as the Monitor type, or
+as a turreted iron-clad. This vessel is 330 feet long, 57<span class="enum">1</span>&#8725;<span class="denom">2</span>
+feet wide, and 36 feet deep, drawing 24<span class="enum">1</span>&#8725;<span class="denom">2</span> feet of water.
+The total weight of ship and contents is over 8,000 tons,
+and the engines are of over 8,500 horse-power. The armor
+is 6 and 7 inches thick on the hull, and 8 inches on the two
+turrets, over a heavy teak backing. The turrets contain
+each two 12-inch rifled guns, weighing 25 tons each, and,<span class='pagenum'><a name="Page_414" id="Page_414">[414]</a></span>
+with a charge of 70 pounds of powder, throwing a shot of
+600 pounds weight with a velocity of 1,200 feet per second,
+and giving it a <i>vis viva</i> equivalent to the raising of
+over 6,100 tons one foot high, and equal to the work of penetrating
+an iron plate 13<span class="enum">1</span>&#8725;<span class="denom">2</span> inches thick. This immense vessel
+is driven by a pair of &#8220;single-cylinder&#8221; engines having
+steam-cylinders <i>ten feet</i> in diameter and of 4<span class="enum">1</span>&#8725;<span class="denom">2</span> feet stroke
+of piston, driving a two-bladed Griffith screw of 23<span class="enum">1</span>&#8725;<span class="denom">2</span> feet
+diameter and 26<span class="enum">1</span>&#8725;<span class="denom">2</span> feet pitch, 65 revolutions, at the maximum
+speed of 14.9 knots, or about 17<span class="enum">1</span>&#8725;<span class="denom">2</span> miles, an hour.
+To drive these powerful engines, boilers having an aggregate
+of about 25,000 square feet (or more than a half-acre)
+of heating-surface are required, with 900 square feet
+of grate-surface. The refrigerating surface in the condensers
+has an area of 16,500 square feet&mdash;over one-third of an
+acre. The cost of these engines and boilers was &pound;66,500.</p>
+
+<p>Were all this vast steam-power developed, giving the
+vessel a speed of 15 knots, the ship, if used as a &#8220;ram,&#8221;
+would strike an enemy at rest with the tremendous &#8220;energy&#8221;
+of 48,000 foot-tons&mdash;equal to the shock of the projectiles
+of eight or nine such guns as are carried by the iron-clad
+itself, simultaneously discharged upon one spot.</p>
+
+<p>But even this great vessel is less formidable than later
+vessels. One of the latter, the Inflexible, is a shorter but
+wider and deeper ship than the Monarch, measuring 320
+feet long, 75 feet beam, and 25 draught, displacing over
+10,000 tons. The great rifles carried by this vessel weigh
+81 tons each, throwing shot weighing a half-ton from behind
+iron-plating two feet in thickness. The steam-engines
+are of about the same power as those of the Monarch,
+and give this enormous hull a speed of 14 knots an hour.</p>
+
+<p>The navy of the United States does not to-day possess
+iron-clads of power even approximating that of either of
+several classes of British and other foreign naval vessels.</p>
+
+<div class="figcenter"><a name="Fig146" id="Fig146"></a>
+<img src="images/illo442.png" alt="The Great Eastern" width="556" height="350" />
+<p class="caption"><span class="smcap">Fig. 146.</span>&mdash;The Great Eastern.</p></div>
+
+<p>The largest vessel of any class yet constructed is the
+Great Eastern (<a href="#Fig146">Fig. 146</a>), begun in 1854 and completed
+in<span class='pagenum'><a name="Page_415" id="Page_415">[415]</a></span>
+1859, by J. Scott Russell, on the Thames, England. This ship
+is 680 feet long, 83 feet wide, 58 feet deep, 28 feet draught,
+and of 24,000 tons measurement. There are four paddle and
+four screw engines, the former having steam-cylinders 74
+inches in diameter, with 14 feet stroke, the latter 84 inches in
+diameter and 4 feet stroke. They are collectively of 10,000
+actual horse-power. The paddle-wheels are 56 feet in diameter,
+the screw 24 feet. The steam-boilers supplying the
+paddle-engines have 44,000 square feet (more than an acre)
+of heating-surface. The boilers supplying the screw-engines
+are still larger. At 30 feet draught, this great vessel
+displaces 27,000 tons. The engines were designed to develop
+10,000 horse-power, driving the ship at the rate of
+16<span class="enum">1</span>&#8725;<span class="denom">2</span> statute miles an hour.</p>
+
+<p>The figures quoted in the descriptions of these great
+steamships do not enable the non-professional reader to form
+a conception of the wonderful power which is concentrated
+within so small a space as is occupied by their steam-machinery.
+The &#8220;horse-power&#8221; of the engines is that determined<span class='pagenum'><a name="Page_416" id="Page_416">[416]</a></span>
+by James Watt as the maximum obtainable for eight
+hours a day from the strongest London draught-horses.
+The ordinary average draught-horse would hardly be able
+to exert two-thirds as much during the eight hours&#8217; steady
+work of a working-day. The working-day of the steam-engine,
+on the other hand, is twenty-four hours in length.</p>
+
+<div class="figcenter"><a name="Fig147" id="Fig147"></a>
+<img src="images/illo443.png" alt="The Great Eastern At Sea" width="400" height="316" />
+<p class="caption"><span class="smcap">Fig. 147.</span>&mdash;The Great Eastern at Sea.</p></div>
+
+<p>The work of the 10,000 horse-power engines of the
+Great Eastern could be barely equaled by the efforts of
+15,000 horses; but to continue their work uninterruptedly,
+day in and day out, for weeks together, as when done by
+steam, would require at least three relays, or 45,000 horses.
+Such a stud would weigh 25,000 tons, and if harnessed
+&#8220;tandem&#8221; would extend thirty miles. It is only by such a
+comparison that the mind can begin to comprehend the
+utter impossibility of accomplishing by means of animal<span class='pagenum'><a name="Page_417" id="Page_417">[417]</a></span>
+power the work now done for the world by steam. The
+cost of the greater power is but about one-tenth that of
+horse-power, and by its means tasks are accomplished with
+ease which are absolutely impossible of accomplishment by
+animal power.</p>
+
+<p>It is estimated that the total steam-power of the world
+is about 15,000,000 horse-power, and that, were horses actually
+employed to do the work which these engines would
+be capable of doing were they kept constantly in operation,
+the number required would exceed 60,000,000.</p>
+
+<p>Thus, from the small beginnings of the Comte d&#8217;Auxiron
+and the Marquis de Jouffroy in France, of Symmington
+in Great Britain, and of Henry, Rumsey, and Fitch, and of
+Fulton and Stevens, in the United States, steam-navigation
+has grown into a great and inestimable aid and blessing to
+mankind.</p>
+
+<p>We to-day cross the ocean with less risk, and transport
+ourselves and our goods at as little cost in either time
+or money as, at the beginning of the century, our parents
+experienced in traveling one-tenth the distance.</p>
+
+<p>It is largely in consequence of this ingenious application
+of a power that reminds one of the fabled genii of Eastern
+romance, that the mechanic and the laborer of to-day enjoy
+comforts and luxuries that were denied to wealth, and to
+royalty itself, a century ago.</p>
+
+<p>The magnitude of our modern steamships excites the
+wonder and admiration of even the people of our own time;
+and there is certainly no creation of art that can be grander
+in appearance than a transatlantic steamer a hundred and
+fifty yards in length, and weighing, with her stores, five or
+six thousand tons, as she starts on her voyage, moved by
+engines equal in power to the united strength of thousands
+of horses; none can more fully awaken a feeling of awe
+than an immense structure like the great modern iron-clads
+(<a href="#Fig145">Fig. 145</a>), vessels having a total weight of 8,000 to 10,000
+tons, and propelled by steam-engines of as many horse-power,<span class='pagenum'><a name="Page_418" id="Page_418">[418]</a></span>
+carrying guns whose shot penetrate solid iron 20
+inches thick, and having a power of impact, when steaming
+at moderate speed, sufficient to raise 35,000 tons a foot high.</p>
+
+<p>Far more huge than the Monarch among the iron-clads
+even is that prematurely-built monster, the Great Eastern
+(<a href="#Fig147">Fig. 147</a>), already described, an eighth of a mile long, and
+with steam doing the work of a stud of 45,000 horses.</p>
+
+<p><a name="Darwin" id="Darwin"></a>Thus we are to-day witnessing the literal fulfillment of
+the predictions of Oliver Evans and of John Stevens, and
+almost that contained in the couplets written by the poet
+Darwin, who, more than a century ago, before even the
+earliest of Watt&#8217;s improvements had become generally
+known, sang:</p>
+
+<div class="poem"><div class="stanza">
+<span class="i0">&#8220;Soon shall thy arm, unconquered Steam, afar<br /></span>
+<span class="i2">Drag the slow barge, or drive the rapid car;<br /></span>
+<span class="i2">Or, on wide-waving wings expanded, bear<br /></span>
+<span class="i2">The flying chariot through the fields of air.&#8221;<br /></span>
+</div></div>
+
+<p>&nbsp;</p>
+<hr class="l05" />
+<div class="colleft">
+
+<div class="footnote"><p class="left"><a name="Footnote_85_85" id="Footnote_85_85"></a><a href="#FNanchor_85_85"><span class="label">[85]</span></a> The invention of Messrs. Charles T. Porter and John F. Allen.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_86_86" id="Footnote_86_86"></a><a href="#FNanchor_86_86"><span class="label">[86]</span></a> Invented by Mr. John F. Allen.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_87_87" id="Footnote_87_87"></a><a href="#FNanchor_87_87"><span class="label">[87]</span></a> Or not far from 600 times the cube root of the length of stroke, measured
+in feet.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_88_88" id="Footnote_88_88"></a><a href="#FNanchor_88_88"><span class="label">[88]</span></a> Perkins was a native of Newburyport, Mass. He was born July 9,
+1766, and died in London, July 30, 1849. He went to England when fifty-two
+years of age, to introduce his inventions.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_89_89" id="Footnote_89_89"></a><a href="#FNanchor_89_89"><span class="label">[89]</span></a> It was when writing of this engine that Stuart wrote, in 1824: &#8220;Judging
+from the rapid strides the steam-engine has made <i>during the last forty
+years</i> to become a universal first-mover, and from the experience that has
+arisen from that extension, we feel convinced that every invention which
+diminishes its size without impairing its power brings it a step nearer to the
+assistance of the &#8216;world&#8217;s great laborers,&#8217; the husbandman and the peasant,
+for whom, as yet, it performs but little. At present, it is made occasionally
+to tread out the corn. What honors await not that man who may
+yet direct its mighty power to plough, to sow, to harrow, and to reap!&#8221; The
+progress of the steam-engine during those forty years does not to-day appear
+so astounding. The sentiment here expressed has lost none of its
+truth, nevertheless.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_90_90" id="Footnote_90_90"></a><a href="#FNanchor_90_90"><span class="label">[90]</span></a> Galloway and Hebert, on the Steam-Engine. London, 1836.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_91_91" id="Footnote_91_91"></a><a href="#FNanchor_91_91"><span class="label">[91]</span></a> &#8220;The High-Pressure Steam-Engine,&#8221; etc. By Dr. Ernst
+Alban. Translated by William Pole, F. R. A. S. London, 1847.</p></div>
+</div>
+
+<div class="footnote"><p><a name="Footnote_92_92" id="Footnote_92_92"></a><a href="#FNanchor_92_92"><span class="label">[92]</span></a> Invented by Joseph Maudsley, of London, 1827.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_93_93" id="Footnote_93_93"></a><a href="#FNanchor_93_93"><span class="label">[93]</span></a> January, 1884, over 120,000 miles.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_94_94" id="Footnote_94_94"></a><a href="#FNanchor_94_94"><span class="label">[94]</span></a> <i>Railroad Gazette.</i></p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_95_95" id="Footnote_95_95"></a><a href="#FNanchor_95_95"><span class="label">[95]</span></a> The steam-cylinders of the engines of steamers Bristol and Providence
+are 110 inches in diameter and of 12 feet stroke.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_96_96" id="Footnote_96_96"></a><a href="#FNanchor_96_96"><span class="label">[96]</span></a> Burned in 1877.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_97_97" id="Footnote_97_97"></a><a href="#FNanchor_97_97"><span class="label">[97]</span></a> <i>Vide</i> &#8220;Memoir of John Elder,&#8221; W. J. M. Rankine, Glasgow, 1871.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_98_98" id="Footnote_98_98"></a><a href="#FNanchor_98_98"><span class="label">[98]</span></a> &#8220;Official Catalogue,&#8221; 1862, vol. iv., Class viii., p. 123.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_99_99" id="Footnote_99_99"></a><a href="#FNanchor_99_99"><span class="label">[99]</span></a> <i>Journal Franklin Institute</i>, 1870. H. B. M. S. Monarch.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_100_100" id="Footnote_100_100"></a><a href="#FNanchor_100_100"><span class="label">[100]</span></a> London <i>Engineering</i>, 1875.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_101_101" id="Footnote_101_101"></a><a href="#FNanchor_101_101"><span class="label">[101]</span></a> <i>Vide</i> &#8220;Report on Machinery and Manufactures, etc., at Vienna,&#8221; by
+the author, Washington, 1875.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_102_102" id="Footnote_102_102"></a><a href="#FNanchor_102_102"><span class="label">[102]</span></a> Still in use on the Hoboken ferry-boats.</p></div>
+
+<hr class="l05" />
+
+<div class="figcenter"><img src="images/illo445.png" alt="Ornament" width="200" height="249" /></div>
+
+
+<hr class="c40" />
+<p class='pagenum'><a name="Page_419" id="Page_419">[419]</a></p>
+<h2><a name="CHAPTER_VII" id="CHAPTER_VII"></a>CHAPTER VII.</h2>
+
+<h3><i>THE PHILOSOPHY OF THE STEAM-ENGINE.</i></h3>
+
+<hr class="c05" />
+<h4><span class="smcap">The History of its Growth; Energetics and Thermo-dynamics.</span></h4>
+<hr class="c05" />
+
+<div class="blockquot"><p>&#8220;Of all the features which characterize this progressive economical
+movement of civilized nations, that which first excites attention, through
+its intimate connection with the phenomena of production, is the perpetual
+and, so far as human foresight can extend, the unlimited growth of man&#8217;s
+power over Nature. Our knowledge of the properties and laws of physical
+objects shows no sign of approaching its ultimate boundaries; it is advancing
+more rapidly, and in a greater number of directions at once, than in any
+previous age or generation, and affording such frequent glimpses of unexplored
+fields beyond as to justify the belief that our acquaintance with
+Nature is still almost in its infancy.&#8221;&mdash;<span class="smcap">Mill.</span></p></div>
+<hr class="c05" />
+
+<p>The growth of the philosophy of the steam-engine presents
+as interesting a study as that of the successive changes
+which have occurred in its mechanism.</p>
+
+<p>In the operation of the steam-engine we find illustrated
+many of the most important principles and facts which constitute
+the physical sciences. The steam-engine is an exceedingly
+ingenious, but, unfortunately, still very imperfect,
+machine for transforming the heat-energy obtained by the
+chemical combination of a combustible with the supporter
+of combustion into mechanical energy. But the original
+source of all this energy is found far back of its first appearance
+in the steam-boiler. It had its origin at the beginning,
+when all Nature came into existence. After the solar
+system had been formed from the nebulous chaos of creation,
+the glowing mass which is now called the sun was the<span class='pagenum'><a name="Page_420" id="Page_420">[420]</a></span>
+depository of a vast store of heat-energy, which was thence
+radiated into space and showered upon the attendant worlds
+in inconceivable quantity and with unmeasured intensity.
+During the past life of the globe, the heat-energy received
+from the sun upon the earth&#8217;s surface was partly expended
+in the production of great forests, and the storage, in the
+trunks, branches, and leaves of the trees of which they were
+composed, of an immense quantity of carbon, which had
+previously existed in the atmosphere, combined with oxygen,
+as carbonic acid. The great geological changes which
+buried these forests under superincumbent strata of rock
+and earth resulted in the formation of coal-beds, and the
+storage, during many succeeding ages, of a vast amount of
+carbon, of which the affinity for oxygen remained unsatisfied
+until finally uncovered by the hand of man. Thus we
+owe to the heat and light of the sun, as was pointed out by
+George Stephenson, the incalculable store of potential energy
+upon which the human race is so dependent for life
+and all its necessaries, comforts, and luxuries.</p>
+
+<p>This coal, thrown upon the grate in the steam-boiler,
+takes fire, and, uniting again with the oxygen, sets free
+heat in precisely the same quantity that it was received
+from the sun and appropriated during the growth of the
+tree. The actual energy thus rendered available is transferred,
+by conduction and radiation, to the water in the
+steam-boiler, converts it into steam, and its mechanical
+effect is seen in the expansion of the liquid into vapor
+against the superincumbent pressure. Transferred from
+the boiler to the engine, the steam is there permitted to
+expand, doing work, and the heat-energy with which it is
+charged becomes partly converted into mechanical energy,
+and is applied to useful work in the mill or to driving the
+locomotive or the steamboat.</p>
+
+<p>Thus we may trace the store of energy received from
+the sun and contained in our coal through its several changes
+until it is finally set at work; and we might go still further<span class='pagenum'><a name="Page_421" id="Page_421">[421]</a></span>
+and observe how, in each case, it is again usually re-transformed
+and again set free as heat-energy.</p>
+
+<p>The transformation which takes place in the furnace is
+a chemical change; the transfer of heat to the water and
+the subsequent phenomena accompanying its passage
+through the engine are physical changes, some of which
+require for their investigation abstruse mathematical operations.
+A thorough comprehension of the principles governing
+the operation of the steam-engine, therefore, can only
+be attained after studying the phenomena of physical
+science with sufficient minuteness and accuracy to be able
+to express with precision the laws of which those sciences
+are constituted. The study of the philosophy of the steam-engine
+involves the study of chemistry and physics, and of
+the new science of energetics, of which the now well-grown
+science of thermo-dynamics is a branch. This sketch of the
+growth of the steam-engine may, therefore, be very properly
+concluded by an outline of the growth of the several
+sciences which together make up its philosophy, and
+especially of the science of thermo-dynamics, which is peculiarly
+the science of the steam-engine and of the other
+heat-engines.</p>
+
+<p>These sciences, like the steam-engine itself, have an origin
+which antedates the commencement of the Christian
+era; but they grew with an almost imperceptible growth
+for many centuries, and finally, only a century ago, started
+onward suddenly and rapidly, and their progress has never
+since been checked. They are now fully-developed and
+well-established systems of natural philosophy. Yet, like
+that of the steam-engine and of its companion heat-engines,
+their growth has by no means ceased; and, while the student
+of science cannot do more than indicate the direction
+of their progress, he can readily believe that the beginning
+of the end is not yet reached in their movement toward
+completeness, either in the determination of facts or in the
+codification of their laws.</p>
+
+<p><span class='pagenum'><a name="Page_422" id="Page_422">[422]</a></span>When Hero lived at Alexandria, the great &#8220;Museum&#8221;
+was a most important centre, about which gathered the
+teachers of all then known philosophies and of all the then
+recognized but unformed sciences, as well as of all those
+technical branches of study which had already been so far
+developed as to be capable of being systematically taught.
+Astronomical observations had been made regularly and
+uninterruptedly by the Chaldean astrologers for two thousand
+years, and records extending back many centuries had
+been secured at Babylon by Calisthenes and given to Aristotle,
+the father of our modern scientific method. Ptolemy
+had found ready to his hand the records of Chaldean observers
+of eclipses extending back nearly 650 years, and
+marvelously accurate.<a name="FNanchor_103_103" id="FNanchor_103_103"></a><a href="#Footnote_103_103" class="fnanchor">[103]</a></p>
+
+<p>A rude method of printing with an engraved roller on
+plastic clay, afterward baked, thus making up ceramic libraries,
+was practised long previous to this time; and in
+the alcoves in which Hero worked were many of these
+books of clay.</p>
+
+<p>This great Library and Museum of Alexandria was
+founded three centuries before the birth of Christ, by Ptolemy
+Soter, who established as his capital that great Egyptian
+city when the death of his brother, the youthful but
+famous conqueror whose name he gave it, placed him upon
+the throne of the colossal successor of the then fallen
+Persian Empire. The city itself, embellished with every
+ornament and provided with every luxury that the wealth
+of a conquered world or the skill, taste, and ingenuity of
+the Greek painters, sculptors, architects, and engineers
+could provide, was full of wonders; it was a wonder in itself.
+This rich, populous, and magnificent city was the
+metropolis of the then civilized world. Trade, commerce,
+manufactures, and the fine arts were all represented in this<span class='pagenum'><a name="Page_423" id="Page_423">[423]</a></span>
+splendid exchange, and learning found its most acceptable
+home and noblest field within the walls of Ptolemy&#8217;s Museum;
+its disciples found themselves welcomed and protected
+by its founder and his successors, Philadelphus and
+the later Ptolemies.</p>
+
+<p>The Alexandrian Museum was founded with the declared
+object of collecting all written works of authority,
+of promoting the study of literature and art, and of stimulating
+and assisting experimental and mathematical scientific
+investigation and research. The founders of modern
+libraries, colleges, and technical schools have their prototype
+in intelligence, public spirit, and liberality, in the first
+of the Ptolemies, who not only spent an immense sum in
+establishing this great institution, but spared no expense
+in sustaining it. Agents were sent out into all parts of
+the world, purchasing books. A large staff of scribes was
+maintained at the museum, whose duty it was to multiply
+copies of valuable works, and to copy for the library
+such works as could not be purchased.</p>
+
+<p>The faculty of the museum was as carefully organized
+as was the plan of its administration. The four principal
+faculties of astronomy, literature, mathematics, and medicine
+were subdivided into sections devoted to the several
+branches of each department. The collections of the museum
+were as complete as the teachers of the undeveloped
+sciences of the time could make them. Lectures were given
+in all branches of study, and the number of students was
+sometimes as great as twelve or thirteen thousand. The
+number of books which were collected here, when the barbarian
+leaders of the Roman troops under C&aelig;sar burned
+the greater part of it, was stated to be 700,000. Of these,
+400,000 were within the museum itself, and were all destroyed;
+the rest were in the temple of Serapis, and, for
+the time, escaped destruction.</p>
+
+<p>The greatest of all the great men who lived at Alexandria
+at the time of the establishment of the museum was<span class='pagenum'><a name="Page_424" id="Page_424">[424]</a></span>
+Aristotle, the teacher of Alexander and the friend of Ptolemy.
+It is to Aristotle that we owe the systematization of
+the philosophical ideas of Plato and the creation of the
+inductive method, in which has originated all modern science.
+It is to the learned men of Alexandria that we are
+indebted for so effective an application of the Aristotelian
+philosophy that all the then known sciences were given
+form, and were so thoroughly established that the work of
+modern science has been purely one of development.</p>
+
+<p>The inductive method, which built up all the older
+sciences, and which has created all those of recent development,
+consists, first, in the discovery and quantitative
+determination of facts; secondly, when a sufficient number
+of facts have been thus observed and defined, in the grouping
+of those facts, and the detection, by a study of their
+mutual relations, of the natural laws which give rise to or
+regulate them. This simple method is that&mdash;and the only&mdash;method
+by which science advances. By this method, and
+by it only, do we acquire connected and systematic knowledge
+of all the phenomena of Nature of which the physical
+sciences are cognizant. It is only by the application of this
+Aristotelian method and philosophy that we can hope to
+acquire exact scientific knowledge of existing phenomena,
+or to become able to anticipate the phenomena which are
+to distinguish the future. The Aristotelian method of observing
+facts, and of inductive reasoning with those facts
+as a basis, has taught the chemist the properties of the
+known elementary substances and their characteristic behavior
+under ascertained conditions, and has taught him
+the laws of combination and the effects of their union, enabling
+him to predict the changes and the phenomena,
+chemical and physical, which inevitably follow their contact
+under any specified set of conditions.</p>
+
+<p>It is this process which has enabled the physicist to ascertain
+the methods of molecular motion which give us
+light, heat, or electricity, and the range of action and the<span class='pagenum'><a name="Page_425" id="Page_425">[425]</a></span>
+laws which govern the transfer of energy from one of these
+modes of motion to another. It was this method of study
+which enabled James Watt to detect and to remedy the
+defects of the Newcomen engine, and it is by the Aristotelian
+philosophy that the engineer of to-day is taught to construct
+the modern steamship, and to predict, before the keel
+is laid or a blow struck in the workshop or the ship-yard,
+what will be the weight of the vessel, its cargo-carrying
+capacity, the necessary size and power of its engines, the
+quantity of coal which they will require per day while
+crossing the ocean, the depth at which the great hull will
+float in the water, and the exact speed that the vessel will
+attain when the engines are exerting their thousand or their
+ten thousand horse-power.</p>
+
+<p>It was at Alexandria that this mighty philosophy was
+first given a field in which to work effectively. Here Ptolemy
+studied astronomy and &#8220;natural philosophy;&#8221; Archimedes
+applied himself to the studies which attract the
+mathematician and engineer; Euclid taught his royal pupil
+those elements of geometry which have remained standard
+twenty-two centuries; Eratosthenes and Hipparchus studied
+and taught astronomy, and inaugurated the existing system
+of quantitative investigation, proving the spherical form of
+the earth; and Ctesibius and Hero studied pneumatics and
+experimented with the germs of the steam-engine and of
+less important machines.</p>
+
+<p>When, seven centuries later, the destruction of this
+splendid institution was signalized by the death of that
+brilliant scholar and heathen teacher of philosophy, Hypatia,
+at the hands of the more heathenish fanatics who tore
+her in pieces at the foot of the cross, and by the dispersion
+of the library left by C&aelig;sar&#8217;s soldiers in the Serapeum, a true
+philosophy had been created, and the inductive method was
+destined to live and to overcome every obstacle in the path
+of enlightenment and civilization. The fall of the Alexandrian
+Museum, sad as was the event, could not destroy the<span class='pagenum'><a name="Page_426" id="Page_426">[426]</a></span>
+new philosophical method. Its fruits ripened slowly but
+surely, and we are to-day gathering a plentiful harvest.</p>
+
+<p>Science, literature, and the arts, all remained dormant
+for several centuries after the catastrophe which deprived
+them of the light in which they had flourished so many
+centuries. The armies of the caliphs made complete the
+shameful work of destruction begun by the armies of C&aelig;sar,
+and the Alexandrian Library, partly destroyed by the
+Romans, was completely dispersed by the Patriarchs and
+their ignorant and fanatical followers; and finally all the
+scattered remnants were burned by the Saracens. But
+when the thirst for conquest had become satiated or appeased,
+the followers of the caliphs turned their attention
+to intellectual pursuits, and the ninth century of the Christian
+era saw once more such a collection of philosophical
+writings, collected at Bagdad, as could only be gathered by
+the power and wealth of the later conquerors of the world.
+Philosophy once again resumed its empire, and another race
+commenced the study of the mathematics of India and of
+Greece, the astronomy of Chaldea, and of all the sciences
+which originated in Greece and in Egypt. By the conquest
+of Spain by the Saracens, the new civilization was imported
+into Western Europe and libraries were gathered together
+under the Moorish rulers, one of which numbered more
+than a half-million volumes. Wherever Saracen armies
+had extended Mohammedan rule, schools and colleges, libraries
+and collections of philosophical apparatus, were
+scattered in strange profusion; and students, teachers, philosophers,
+of all&mdash;the speculative as well as the Aristotelian&mdash;schools,
+gathered together at these intellectual
+ganglia, as enthusiastic in their work as were their Alexandrian
+predecessors. The endowment of colleges, that
+truest gauge of the intelligence of the wealthy classes of
+any community, became as common&mdash;perhaps more so&mdash;as
+at the present time, and provision was made for the education
+of rich and poor alike. The mathematical sciences,<span class='pagenum'><a name="Page_427" id="Page_427">[427]</a></span>
+and the wonderful and beautiful phenomena which&mdash;but a
+thousand years later&mdash;were afterward grouped into a science
+and called chemistry, were especially attractive to the Arabian
+scholars, and technical applications of discovered facts
+and laws assisted in a wonderfully rapid development of
+arts and manufactures.</p>
+
+<p>When, a thousand years after Christ, the centre of intellectual
+activity and of material civilization had drifted
+westward into Andalusia, the foundation of every modern
+physical science except that now just taking shape&mdash;the
+all-grasping science of energetics&mdash;had been laid with experimentally
+derived facts; and in mathematics there had
+been erected a symmetrical and elegant superstructure.
+Even that underlying principle of all the sciences, the principle
+of the persistence of energy, had been, perhaps unwittingly,
+enunciated.</p>
+
+<p>Distinguished historians have shown how the progress
+of civilization in Europe resulted in the creation, during
+the middle ages, of the now great middle class, which, holding
+the control of political power, governs every civilized
+nation, and has come into power so gradually that it was
+only after centuries that its influence was seen and felt.
+This, which Buckle<a name="FNanchor_104_104" id="FNanchor_104_104"></a><a
+href="#Footnote_104_104" class="fnanchor">[104]</a> calls the intellectual class, first became
+active, independently of the military and of the clergy, in
+the fourteenth century. In the two succeeding centuries
+this class gained power and influence; and in the seventeenth
+century we find a magnificent advance in all branches
+of science, literature, and art, marking the complete emancipation
+of the intellect from the artificial conditions which
+had so long repressed its every effort at advancement.</p>
+
+<p>Another great social revolution thus occurred, following
+another period of centuries of intellectual stagnation.
+The Saracen invaders were driven from Europe; the Crusaders
+invaded Palestine, in the vain effort to recover from
+the hands of the infidels the Holy Sepulchre and the Holy<span class='pagenum'><a name="Page_428" id="Page_428">[428]</a></span>
+Land; and intestine broils and inter-state conflicts, as well
+as these greater social movements, withdrew the minds of
+men once more from the arts of peace and the pursuits of
+scholars. It is not, then, until the beginning of the seventeenth
+century&mdash;the time of Galileo and of Newton&mdash;that we
+find the nations of Europe sufficiently quiet and secure to
+permit general attention to intellectual vocations, although it
+was a half-century earlier (1543) that Copernicus left to the
+world that legacy which revolutionized the theories of the
+astronomers and established as correct the hypothesis which
+made the sun the centre of the solar system.</p>
+
+<p>Galileo now began to overturn the speculations of the
+deductive philosophers, and to proclaim the still disputed
+principle that the book of Nature is a trustworthy commentary
+in the study of theological and revealed truths, so
+far as they affect or are affected by science; he suffered
+martyrdom when he proclaimed the fact that God&#8217;s laws,
+as they now stand, had been instituted without deference
+to the preconceived notions of the most ignorant of men.
+Bruno had a few years earlier (1600) been burned at the
+stake for a similar offense.</p>
+
+<p>Galileo was perhaps the first, too, to combine invariably
+in application the idea of Plato, the philosophy of Aristotle,
+and the methods of modern experimentation, to form
+the now universal scientific method of experimental philosophy.
+He showed plainly how the grouping of ascertained
+facts, in natural sequence, leads to the revelation of the law
+of that sequence, and indicated the existence of a principle
+which is now known as the law of continuity&mdash;the law that
+in all the operations of Nature there is to be seen an unbroken
+chain of effect leading from the present back into a
+known or an unknown past, toward a cause which may or
+may not be determinable by science or known to history.</p>
+
+<p>Galileo, the Italian, was worthily matched by Newton,
+the prince of English philosophers. The science of theoretical
+mechanics was hardly beginning to assume the position<span class='pagenum'><a name="Page_429" id="Page_429">[429]</a></span>
+which it was afterward given among the sciences; and
+the grand work of collating facts already ascertained, and
+of definitely stating principles which had previously been
+vaguely recognized, was splendidly done by Newton. The
+needs of physical astronomy urged this work upon him.</p>
+
+<p>Da Vinci had, in the latter half of the fifteenth century,
+summarized as much of the statics of mechanical philosophy
+as had, up to his time, been given shape; he also rewrote
+and added very much to what was known on the subject of
+friction, and enunciated its laws. He had evidently a good
+idea of the principle of &#8220;virtual velocities,&#8221; that simple
+case of equivalence of work, in a connected system, which
+has done such excellent service since; and with his mechanical
+philosophy this versatile engineer and artist curiously
+mingled much of physical science. Then Stevinus, the
+&#8220;brave engineer of Bruges,&#8221; a hundred years later (1586),
+alternating office and field work, somewhat after the manner
+of the engineer of to-day, wrote a treatise on mechanics,
+which showed the value of practical experience and judgment
+in even scientific work. And thus the path had been
+cleared for Newton.</p>
+
+<p>Meantime, also, Kepler had hit upon the true relations
+of the distances of the planets and their periodic times,
+after spending half a generation in blindly groping for them,
+thus furnishing those great landmarks of fact in the mechanics
+of astronomy; and Galileo had enunciated the laws
+of motion. Thus the foundation of the science of dynamics,
+as distinguished from statics, was laid, and the beginning
+was made of that later science of energetics, of which
+the philosophy of the steam-engine is so largely constituted.</p>
+
+<p>Hooke, Huyghens, and others, had already seen some of
+the principal consequences of these laws; but it remained for
+Newton to enunciate them with the precision of a true mathematician,
+and to base upon them a system of dynamical laws,
+which, complemented by his announcement of the existence
+of the force of gravitation, and his statement of its laws,<span class='pagenum'><a name="Page_430" id="Page_430">[430]</a></span>
+gave a firm basis for all that the astronomer has since done
+in those quantitative determinations of size, weight, and distance,
+and of the movements of the heavenly bodies, which
+compel the wonder and admiration of mankind.</p>
+
+<p>The Arabians and Greeks had noticed that the direction
+taken by a body falling under the action of gravitation was
+directly toward the centre of the earth, wherever its fall
+might occur; Galileo had shown, by his experiments at
+Pisa, that the velocity of fall, second after second, varied
+as the numbers 1, 3, 5, 7, 9, etc., and that the distances
+varied as the squares of the total periods of time during
+which the body was falling, and that it was, in British
+feet, very nearly sixteen times the square of that time in
+seconds. Kepler had proved that the movements of the
+heavenly bodies were just such as would occur under the
+action of central attractive forces and of centrifugal force.</p>
+
+<p>Putting all these things together, Newton was led to
+believe that there existed a &#8220;force of gravity,&#8221; due to the
+attraction, by the great mass of the earth, of its own particles
+and of neighboring bodies, like the moon, of which
+force the influence extended as far, at least, as the latter.
+He calculated the motion of the earth&#8217;s satellite, on the
+assumption that his theory and the then accepted measurements
+of the earth&#8217;s dimensions were correct, and obtained
+a roughly approximate result. Later, in 1679, he revised
+his calculations, using Picard&#8217;s more accurate determination
+of the dimensions of the earth, and obtained a result
+which precisely tallied with careful measurements, made by
+the astronomers, of the moon&#8217;s motion.</p>
+
+<p>The science of mechanics had now, with the publication
+of Newton&#8217;s &#8220;<a href="http://www.gutenberg.org/ebooks/28233">Principia</a>,&#8221; become thoroughly consistent and
+logically complete, so far as was possible without a knowledge
+of the principles of energetics; and Newton&#8217;s enunciations
+of the laws of motion, concise and absolutely perfect
+as they still seem, were the basis of the whole science
+of dynamics, as applied to bodies moving freely under the<span class='pagenum'><a name="Page_431" id="Page_431">[431]</a></span>
+action of applied forces, either constant or variable. They
+are as perfect a basis for that science as are the primary
+principles of geometry for the whole beautiful structure
+which is built up on them.</p>
+
+<p>The three perfect qualitative expressions of dynamical
+law are:</p>
+
+<p>1. Every free body continues in the state in which it
+may be, whether of rest or of rectilinear uniform motion,
+until compelled to deviate from that state by impressed
+forces.</p>
+
+<p>2. Change of motion is proportional to the force impressed,
+and in the direction of the right line in which that
+force acts.</p>
+
+<p>3. Action is always opposed by reaction; action and
+reaction are equal, and in directly contrary directions.</p>
+
+<p>We may add to these principles a definition of a force,
+which is equally and absolutely complete:</p>
+
+<p><i>Force</i> is that which produces, or tends to produce, motion,
+or change of motion, in bodies. It is measured statically
+by the weight that will counterpoise it, or by the
+pressure which it will produce, and dynamically by the velocity
+which it will produce, acting in the unit of time on
+the unit of mass.</p>
+
+<p>The quantitative determinations of dynamic effects of
+forces are always readily made when it is remembered that
+the effect of a force equal to its own weight, when the body
+is free to move, is to produce in one second a velocity of
+32.2 feet per second, which quantity is the unit of dynamic
+measurement.</p>
+
+<p><i>Work</i> is the product of the resistance met in any instance
+of the exertion of a force, into the distance through
+which that force overcomes the resistance.</p>
+
+<p><i>Energy</i> is the work which a body is capable of doing,
+by its weight or inertia, under given conditions. The energy
+of a falling body, or of a flying shot, is about <span class="enum">1</span>&#8725;<span class="denom">64</span> its
+weight multiplied by the square of its velocity, or, which<span class='pagenum'><a name="Page_432" id="Page_432">[432]</a></span>
+is the same thing, the product of its weight into the height
+of fall or height due its velocity. These principles and
+definitions, with the long-settled definitions of the primary
+ideas of space and time, were all that were needed to lead
+the way to that grandest of all physical generalizations,
+the doctrine of the persistence or conservation of all energy,
+and to its corollary declaring the equivalence of all forms
+of energy, and also to the experimental demonstration of
+the transformability of energy from one mode of existence
+to another, and its universal existence in the various modes
+of motion of bodies and of their molecules.</p>
+
+<p>Experimental physical science had hardly become acknowledged
+as the only and the proper method of acquiring
+knowledge of natural phenomena at the time of Newton;
+but it soon became a generally accepted principle. In
+physics, Gilbert had made valuable investigations before
+Newton, and Galileo&#8217;s experiments at Pisa had been examples
+of similarly useful research. In chemistry, it was only
+when, a century later, Lavoisier showed by his splendid example
+what could be done by the skillful and intelligent
+use of quantitative measurements, and made the balance
+the chemist&#8217;s most important tool, that a science was formed
+comprehending all the facts and laws of chemical change
+and molecular combination. We have already seen how
+astronomy and mathematics together led philosophers to
+the creation and the study of what finally became the science
+of mechanics, when experiment and observation were finally
+brought to their aid. We can now see how, in all these
+physical sciences, four primitive ideas are comprehended:
+matter, force, motion, and space&mdash;which latter two terms
+include all relations of position.</p>
+
+<p>Based on these notions, the science of mechanics comprehends
+four sections, which are of general application in
+the study of all physical phenomena. These are:</p>
+
+<p><i>Statics</i>, which treats of the action and effect of forces.</p>
+
+<p><i>Kinematics</i>, which treats of relations of motion simply.<span class='pagenum'><a name="Page_433" id="Page_433">[433]</a></span></p>
+
+<p><i>Dynamics</i>, or kinetics, which treats of simple motion as
+an effect of the action of forces.</p>
+
+<p><i>Energetics</i>, which treats of modifications of energy
+under the action of forces, and of its transformation from
+one mode of manifestation to another, and from one body
+to another.</p>
+
+<p>Under the latter of these four divisions of mechanical
+philosophy is comprehended that latest of the minor sciences,
+of which the heat-engines, and especially the steam-engine,
+illustrate the most important applications&mdash;<i>Thermo-dynamics</i>.
+This science is simply a wider generalization
+of principles which, as we have seen, have been established
+one at a time, and by philosophers widely separated both
+geographically and historically, by both space and time,
+and which have been slowly aggregated to form one after
+another of the sciences, and out of which, as we now are
+beginning to see, we are slowly evolving wider generalizations,
+and thus tending toward a condition of scientific
+knowledge which renders more and more probable the truth
+of Cicero&#8217;s declaration: &#8220;One eternal and immutable law
+embraces all things and all times.&#8221; At the basis of the
+whole science of energetics lies a principle which was enunciated
+before Science had a birthplace or a name:</p>
+
+<p><i>All that exists, whether matter or force, and in whatever
+form, is indestructible, except by the Infinite Power
+which has created it.</i></p>
+
+<p>That matter is indestructible by finite power became
+admitted as soon as the chemists, led by their great teacher
+Lavoisier, began to apply the balance, and were thus able
+to show that in all chemical change there occurs only a
+modification of form or of combination of elements, and
+no loss of matter ever takes place. The &#8220;persistence&#8221; of
+energy was a later discovery, consequent largely upon the
+experimental determination of the convertibility of heat-energy
+into other forms and into mechanical work, for
+which we are indebted to Rumford and Davy, and to the<span class='pagenum'><a name="Page_434" id="Page_434">[434]</a></span>
+determination of the quantivalence anticipated by Newton,
+shown and calculated approximately by Colding and Mayer,
+and measured with great probable accuracy by Joule.</p>
+
+<div class="figcenter"><a name="Port13" id="Port13"></a>
+<img src="images/illo461.png" alt="Thompson" width="350" height="410" />
+<p class="caption">Benjamin Thompson, Count Rumford.</p></div>
+
+<p>The great fact of the conservation of energy was loosely
+stated by Newton, who asserted that the work of friction
+and the <i>vis viva</i> of the system or body arrested by friction
+were equivalent. In 1798, Benjamin Thompson, Count
+Rumford, an American who was then in the Bavarian service,
+presented a paper<a name="FNanchor_105_105" id="FNanchor_105_105"></a><a href="#Footnote_105_105"
+class="fnanchor">[105]</a> to the Royal Society of Great
+Britain, in which he stated the results of an experiment
+which he had recently made, proving the immateriality of
+heat and the transformation of mechanical into heat energy.<span class='pagenum'><a name="Page_435" id="Page_435">[435]</a></span>
+This paper is of very great historical interest, as the now
+accepted doctrine of the persistence of energy is a generalization
+which arose out of a series of investigations, the
+most important of which are those which resulted in the
+determination of the existence of a definite quantivalent
+relation between these two forms of energy and a measurement
+of its value, now known as the &#8220;mechanical equivalent
+of heat.&#8221; His experiment consisted in the determination
+of the quantity of heat produced by the boring of a
+cannon at the arsenal at Munich.</p>
+
+<p>Rumford, after showing that this heat could not have
+been derived from any of the surrounding objects, or by
+compression of the materials employed or acted upon, says:
+&#8220;It appears to me extremely difficult, if not impossible, to
+form any distinct idea of anything capable of being excited
+and communicated in the manner that heat was excited and
+communicated in these experiments, except it be motion.&#8221;<a name="FNanchor_106_106"
+id="FNanchor_106_106"></a><a href="#Footnote_106_106" class="fnanchor">[106]</a>
+He then goes on to urge a zealous and persistent investigation
+of the laws which govern this motion. He estimates
+the heat produced by a power which he states could easily
+be exerted by one horse, and makes it equal to the &#8220;combustion
+of nine wax candles, each three-quarters of an inch
+in diameter,&#8221; and equivalent to the elevation of &#8220;25.68
+pounds of ice-cold water&#8221; to the boiling-point, or 4,784.4
+heat-units.<a name="FNanchor_107_107" id="FNanchor_107_107"></a><a href="#Footnote_107_107"
+class="fnanchor">[107]</a> The time was stated at &#8220;150 minutes.&#8221; Taking
+the actual power of Rumford&#8217;s Bavarian &#8220;one horse&#8221;
+as the most probable figure, 25,000 pounds raised one foot
+high per minute,<a name="FNanchor_108_108" id="FNanchor_108_108"></a><a
+href="#Footnote_108_108" class="fnanchor">[108]</a> this
+gives the &#8220;mechanical equivalent&#8221;<span class='pagenum'><a name="Page_436" id="Page_436">[436]</a></span>
+of the foot-pound as 783.8 heat-units, differing but 1.5 per
+cent. from the now accepted value.</p>
+
+<p>Had Rumford been able to eliminate all losses of heat
+by evaporation, radiation, and conduction, to which losses
+he refers, and to measure the power exerted with accuracy,
+the approximation would have been still closer. Rumford
+thus made the experimental discovery of the real nature
+of heat, proving it to be a form of energy, and, publishing
+the fact a half-century before the now standard determinations
+were made, gave us a very close approximation to
+the value of the heat-equivalent. Rumford also observed
+that the heat generated was &#8220;exactly proportional to the
+force with which the two surfaces are pressed together,
+and to the rapidity of the friction,&#8221; which is a simple statement
+of equivalence between the quantity of work done, or
+energy expended, and the quantity of heat produced. This
+was the first great step toward the formation of a Science
+of Thermo-dynamics. Rumford&#8217;s work was the corner-stone
+of the science.</p>
+
+<p>Sir Humphry Davy, a little later (1799), published the
+details of an experiment which conclusively confirmed these
+deductions from Rumford&#8217;s work. He rubbed two pieces
+of ice together, and found that they were melted by the
+friction so produced. He thereupon concluded: &#8220;It is evident
+that ice by friction is converted into water.... Friction,
+consequently, does not diminish the capacity of bodies
+for heat.&#8221;</p>
+
+<p>Bacon and Newton, and Hooke and Boyle, seem to
+have anticipated&mdash;long before Rumford&#8217;s time&mdash;all later
+philosophers, in admitting the probable correctness of that
+modern dynamical, or vibratory, theory of heat which considers
+it a mode of motion; but Davy, in 1812, for the first<span class='pagenum'><a name="Page_437" id="Page_437">[437]</a></span>
+time, stated plainly and precisely the real nature of heat,
+saying: &#8220;The immediate cause of the phenomenon of heat,
+then, is motion, and the laws of its communication are precisely
+the same as the laws of the communication of motion.&#8221;
+The basis of this opinion was the same that had
+previously been noted by Rumford.</p>
+
+<p>So much having been determined, it became at once evident
+that the determination of the exact value of the mechanical
+equivalent of heat was simply a matter of experiment;
+and during the succeeding generation this determination
+was made, with greater or less exactness, by several
+distinguished men. It was also equally evident that the
+laws governing the new science of thermo-dynamics could
+be mathematically expressed.</p>
+
+<p>Fourier had, before the date last given, applied mathematical
+analysis in the solution of problems relating to the
+transfer of heat without transformation, and his &#8220;Th&eacute;orie
+de la Chaleur&#8221; contained an exceedingly beautiful treatment
+of the subject. Sadi Carnot, twelve years later (1824),
+published his &#8220;R&eacute;flexions sur la Puissance Motrice du Feu,&#8221;
+in which he made a first attempt to express the principles
+involved in the application of heat to the production of
+mechanical effect. Starting with the axiom that a body
+which, having passed through a series of conditions modifying
+its temperature, is returned to &#8220;its primitive physical
+state as to density, temperature, and molecular constitution,&#8221;
+must contain the same quantity of heat which it had
+contained originally, he shows that the efficiency of heat-engines
+is to be determined by carrying the working fluid
+through a complete cycle, beginning and ending with the
+same set of conditions. Carnot had not then accepted the
+vibratory theory of heat, and consequently was led into
+some errors; but, as will be seen hereafter, the idea just
+expressed is one of the most important details of a theory
+of the steam-engine.</p>
+
+<p>Seguin, who has already been mentioned as one of the<span class='pagenum'><a name="Page_438" id="Page_438">[438]</a></span>
+first to use the fire-tubular boiler for locomotive engines,
+published in 1839 a work, &#8220;Sur l&#8217;Influence des Chemins de
+Fer,&#8221; in which he gave the requisite data for a rough determination
+of the value of the mechanical equivalent of
+heat, although he does not himself deduce that value.</p>
+
+<p>Dr. Julius R. Mayer, three years later (1842), published
+the results of a very ingenious and quite closely approximate
+calculation of the heat-equivalent, basing his
+estimate upon the work necessary to compress air, and on
+the specific heats of the gas, the idea being that the work
+of compression is the equivalent of the heat generated.
+Seguin had taken the converse operation, taking the loss of
+heat of expanding steam as the equivalent of the work done
+by the steam while expanding. The latter also was the
+first to point out the fact, afterward experimentally proved
+by Hirn, that the fluid exhausted from an engine should
+heat the water of condensation less than would the same
+fluid when originally taken into the engine.</p>
+
+<p>A Danish engineer, Colding, at about the same time
+(1843), published the results of experiments made to determine
+the same quantity; but the best and most extended
+work, and that which is now almost universally accepted as
+standard, was done by a British investigator.</p>
+
+<div class="figcenter"><a name="Port14" id="Port14"></a>
+<img src="images/illo466.png" alt="Joule" width="350" height="408" />
+<p class="caption">James Prescott Joule.</p></div>
+
+<p><a href="#Port14">James Prescott Joule</a> commenced the experimental investigations
+which have made him famous at some time
+previous to 1843, at which date he published, in the
+<i>Philosophical Magazine</i>, his earliest method. His first determination
+gave 770 foot-pounds. During the succeeding
+five or six years Joule repeated his work, adopting a considerable
+variety of methods, and obtaining very variable
+results. One method was to determine the heat produced
+by forcing air through tubes; another, and his usual plan,
+was to turn a paddle-wheel by a definite power in a known
+weight of water. He finally, in 1849, concluded these
+researches.</p>
+
+<p>The method of calculating the mechanical equivalent of<span class='pagenum'><a name="Page_439" id="Page_439">[439]</a></span>
+heat which was adopted by Dr. Mayer, of Heilbronn, is as
+beautiful as it is ingenious: Conceive two equal portions of
+atmospheric air to be inclosed, at the same temperature&mdash;as
+at the freezing-point&mdash;in vessels each capable of containing
+one cubic foot; communicate heat to both, retaining the
+one portion at the original volume, and permitting the other
+to expand under a constant pressure equal to that of the
+atmosphere. In each vessel there will be inclosed 0.08073
+pound, or 1.29 ounce, of air. When, at the same temperature,
+the one has doubled its pressure and the other has
+doubled its volume, each will be at a temperature of 525.2&deg;
+Fahr., or 274&deg; C, and each will have double the original
+temperature, as measured on the absolute scale from the<span class='pagenum'><a name="Page_440" id="Page_440">[440]</a></span>
+zero of heat-motion. But the one will have absorbed but
+6<span class="enum">3</span>&#8725;<span class="denom">4</span> British thermal units, while the other will have absorbed
+9<span class="enum">1</span>&#8725;<span class="denom">2</span>. In the first case, all of this heat will have been employed
+in simply increasing the temperature of the air; in
+the second case, the temperature of the air will have been
+equally increased, and, besides, a certain amount of work&mdash;2,116.3
+foot-pounds&mdash;must have been done in overcoming
+the resistance of the air; it is to this latter action that we
+must debit the additional heat which has disappeared. Now,
+(2,116.3/2<span class="enum">3</span>&#8725;<span class="denom">4</span>) = 770 foot-pounds per heat-unit&mdash;almost precisely
+the value derived from Joule&#8217;s experiments. Had Mayer&#8217;s
+measurement been absolutely accurate, the result of his
+calculation would have been an exact determination of the
+heat-equivalent, provided no heat is, in this case, lost by
+internal work.</p>
+
+<p>Joule&#8217;s most probably accurate measure was obtained
+by the use of a paddle-wheel revolving in water or other
+fluid. A copper vessel contained a carefully weighed portion
+of the fluid, and at the bottom was a step, on which
+stood a vertical spindle carrying the paddle-wheel. This
+wheel was turned by cords passing over nicely-balanced
+grooved wheels, the axles of which were carried on friction-rollers.
+Weights hung at the ends of these cords were
+the moving forces. Falling to the ground, they exerted an
+easily and accurately determinable amount of work, <i>W</i> &times; <i>H</i>,
+which turned the paddle-wheel a definite number of revolutions,
+warming the water by the production of an amount
+of heat exactly equivalent to the amount of work done.
+After the weight had been raised and this operation repeated
+a sufficient number of times, the quantity of heat
+communicated to the water was carefully determined and
+compared with the amount of work expended in its development.
+Joule also used a pair of disks of iron rubbing
+against each other in a vessel of mercury, and measured
+the heat thus developed by friction, comparing it with the<span class='pagenum'><a name="Page_441" id="Page_441">[441]</a></span>
+work done. The average of forty experiments with water
+gave the equivalent 772.692 foot-pounds; fifty with mercury
+gave 774.083; twenty with cast-iron gave 774.987&mdash;the
+temperature of the apparatus being from 55&deg; to 60&deg;
+Fahr.</p>
+
+<p>Joule also determined, by experiment, the fact that the
+expansion of air or other gas without doing work produces
+no change of temperature, which fact is predicable from
+the now known principles of thermo-dynamics. He stated
+the results of his researches relating to the mechanical
+equivalent of heat as follows:</p>
+
+<p>1. The heat produced by the friction of bodies, whether
+solid or liquid, is always proportional to the quantity of
+work expended.</p>
+
+<p>2. The quantity required to increase the temperature of
+a pound of water (weighed <i>in vacuo</i> at 55&deg; to 60&deg; Fahr.) by
+one degree requires for its production the expenditure of a
+force measured by the fall of 772 pounds from a height of
+one foot. This quantity is now generally called &#8220;Joule&#8217;s
+equivalent.&#8221;</p>
+
+<p>During this series of experiments, Joule also deduced
+the position of the &#8220;absolute zero,&#8221; the point at which heat-motion
+ceases, and stated it to be about 480&deg; Fahr. below
+the freezing-point of water, which is not very far from the
+probably true value,-493.2&deg; Fahr. (-273&deg; C.), as deduced
+afterward from more precise data.</p>
+
+<p>The result of these, and of the later experiments of
+Hirn and others, has been the admission of the following
+principle:</p>
+
+<p>Heat-energy and mechanical energy are mutually convertible
+and have a definite equivalence, the British thermal
+unit being equivalent to 772 foot-pounds of work, and the
+metric <i>calorie</i> to 423.55, or, as usually taken, 424 kilogrammetres.
+The exact measure is not fully determined, however.</p>
+
+<p>It has now become generally admitted that all forms of<span class='pagenum'><a name="Page_442" id="Page_442">[442]</a></span>
+energy due to physical forces are mutually convertible with
+a definite quantivalence; and it is not yet determined that
+even vital and mental energy do not fall within the same
+great generalization. This quantivalence is the sole basis
+of the science of Energetics.</p>
+
+<p>The study of this science has been, up to the present
+time, principally confined to that portion which comprehends
+the relations of heat and mechanical energy. In the
+study of this department of the science, thermo-dynamics,
+Rankine, Clausius, Thompson, Hirn, and others have acquired
+great distinction. In the investigations which have
+been made by these authorities, the methods of transfer of
+heat and of modification of physical state in gases and vapors,
+when a change occurs in the form of the energy considered,
+have been the subjects of especial study.</p>
+
+<p>According to the law of Boyle and Marriotte, the expansion
+of such fluids follows a law expressed graphically
+by the hyperbola, and algebraically by the expression
+PV<sup><i>x</i></sup> = A, in which, with unchanging temperature, <i>x</i> is equal
+to 1. One of the first and most evident deductions from the
+principles of the equivalence of the several forms of energy
+is that the value of x must increase as the energy expended
+in expansion increases. This change is very marked with
+a vapor like steam&mdash;which, expanded without doing work,
+has an exponent less than unity, and which, when doing
+work by expanding behind a piston, partially condenses, the
+value of <i>x</i> increases to, in the case of steam, 1.111 according
+to Rankine, or, probably more correctly, to 1.135 or more,
+according to Zeuner and Grashof. This fact has an important
+bearing upon the theory of the steam-engine, and
+we are indebted to Rankine for the first complete treatise
+on that theory as thus modified.</p>
+
+<div class="figcenter"><a name="Port15" id="Port15"></a>
+<img src="images/illo470.png" alt="Rankine" width="350" height="409" />
+<p class="caption">Prof. W. J. M. Rankine.</p></div>
+
+<p><a href="#Port15">Prof. Rankine</a> began his investigations as early as 1849,
+at which time he proposed his theory of the molecular constitution
+of matter, now well known as the theory of molecular
+vortices. He supposes a system of whirling rings or<span class='pagenum'><a name="Page_443" id="Page_443">[443]</a></span>
+vortices of heat-motion, and bases his philosophy upon that
+hypothesis, supposing sensible heat to be employed in changing
+the velocity of the particles, latent heat to be the work
+of altering the dimensions of the orbits, and considering the
+effort of each vortex to enlarge its boundaries to be due to
+centrifugal force. He distinguished between real and apparent
+specific heat, and showed that the two methods of
+absorption of heat, in the case of the heating of a fluid, that
+due to simple increase of temperature and that due to increase
+of volume, should be distinguished; he proposed, for
+the latter quantity, the term heat-potential, and for the sum
+of the two, the name of thermo-dynamic function.</p>
+
+<p>Carnot had stated, a quarter of a century earlier, that
+the efficiency of a heat-engine is a function of the two limits
+of temperature between which the machine is worked, and<span class='pagenum'><a name="Page_444" id="Page_444">[444]</a></span>
+not of the nature of the working substance&mdash;an assertion
+which is quite true where the material does not change its
+physical state while working. Rankine now deduced that
+&#8220;general equation of thermo-dynamics&#8221; which expresses
+algebraically the relations between heat and mechanical
+energy, when energy is changing from the one state to the
+other, in which equation is given, for any assumed change
+of the fluids, the quantity of heat transformed. He showed
+that steam in the engine must be partially liquefied by the
+process of expanding against a resistance, and proved that
+the total heat of a perfect gas must increase with rise of
+temperature at a rate proportional to its specific heat under
+constant pressure.</p>
+
+<p>Rankine, in 1850, showed the inaccuracy of the then
+accepted value, 0.2669, of the specific heat of air under constant
+pressure, and calculated its value as 0.24. Three
+years later, the experiments of Regnault gave the value
+0.2379, and Rankine, recalculating it, made it 0.2377. In
+1851, Rankine continued his discussion of the subject, and,
+by his own theory, corroborated Thompson&#8217;s law giving the
+efficiency of a perfect heat-engine as the quotient of the
+range of working temperature to the temperature of the
+upper limit, measured from the absolute zero.</p>
+
+<p>During this period, Clausius, the German physicist, was
+working on the same subject, taking quite a different
+method, studying the mechanical effects of heat in gases,
+and deducing, almost simultaneously with Rankine (1850),
+the general equation which lies at the beginning of the
+theory of the equivalence of heat and mechanical energy.
+He found that the probable zero of heat-motion is at such a
+point that the Carnot function must be approximately the
+reciprocal of the &#8220;absolute&#8221; temperature, as measured with
+the air thermometer, or, stated exactly, that quantity as determined
+by a perfect gas thermometer. He confirmed Rankine&#8217;s
+conclusion relative to the liquefaction of saturated
+vapors when expanding against resistance, and, in 1854,<span class='pagenum'><a name="Page_445" id="Page_445">[445]</a></span>
+adapted Carnot&#8217;s principle to the new theory, and showed
+that his idea of the reversible engine and of the performance
+of a cycle in testing the changes produced still held good,
+notwithstanding Carnot&#8217;s ignorance of the true nature of
+heat. Clausius also gave us the extremely important principle:
+It is impossible for a self-acting machine, unaided, to
+transfer heat from one body at a low temperature to another
+having a higher temperature.</p>
+
+<p>Simultaneously with Rankine and Clausius, Prof. William
+Thomson was engaged in researches in thermo-dynamics
+(1850). He was the first to express the principle of
+Carnot as adapted to the modern theory by Clausius in the
+now generally quoted propositions:<a name="FNanchor_109_109" id="FNanchor_109_109"></a><a
+href="#Footnote_109_109" class="fnanchor">[109]</a></p>
+
+<p>1. When equal mechanical effects are produced by purely
+thermal action, equal quantities of heat are produced or
+disappear by transformation of energy.</p>
+
+<p>2. If, in any engine, a reversal effects complete inversion
+of all the physical and mechanical details of its operation,
+it is a perfect engine, and produces maximum effect with
+any given quantity of heat and with any fixed limits of
+range of temperature.</p>
+
+<p>William Thomson and James Thompson showed, among
+the earliest of their deductions from these principles, the fact,
+afterward confirmed by experiment, that the melting-point
+of ice should be lowered by pressure 0.0135&deg; Fahr, for each
+atmosphere, and that a body which contracts while being
+heated will always have its temperature decreased by sudden
+compression. Thomson applied the principles of energetics
+in extended investigations in the department of electricity,
+while Helmholtz carried some of the same methods
+into his favorite study of acoustics.</p>
+
+<p>The application of now well-settled principles to the
+physics of gases led to many interesting and important deductions:<span class='pagenum'><a name="Page_446" id="Page_446">[446]</a></span>
+Clausius explained the relations between the volume,
+density, temperature, and pressure of gases, and their
+modifications; Maxwell re&euml;stablished the experimentally
+determined law of Dalton and Charles, known also as that
+of Gay-Lussac (1801), which asserts that all masses of equal
+pressure, volume, and temperature, contain equal numbers
+of molecules. On the Continent of Europe, also, Hirn,
+Zeuner, Grashof, Tresca, Laboulaye, and others have, during
+the same period and since, continued and greatly extended
+these theoretical researches.</p>
+
+<p>During all this time, a vast amount of experimental
+work has also been done, resulting in the determination of
+important data without which all the preceding labor would
+have been fruitless. Of those who have engaged in such
+work, Cagniard de la Tour, Andrews, Regnault, Hirn, Fairbairn
+and Tate, Laboulaye, Tresca, and a few others have
+directed their researches in this most important direction
+with the special object of aiding in the advancement of the
+new-born sciences. By the middle of the present century,
+the time which we are now studying, this set of data was
+tolerably complete. Boyle had, two hundred years before,
+discovered and published the law, which is now known by
+his name<a name="FNanchor_110_110" id="FNanchor_110_110"></a><a
+href="#Footnote_110_110" class="fnanchor">[110]</a> and by that of Marriotte,<a
+name="FNanchor_111_111" id="FNanchor_111_111"></a><a href="#Footnote_111_111" class="fnanchor">[111]</a> that the pressure of a
+gas varies inversely as its volume and directly as its density;
+Dr. Black and James Watt discovered, a hundred years
+later (1760), the latent heat of vapors, and Watt determined
+the method of expansion of steam; Dalton, in England, and
+Gay-Lussac, in France, showed, at the beginning of the
+nineteenth century, that all gaseous fluids are expanded by
+equal fractions of their volume by equal increments of temperature;
+Watt and Robison had given tables of the elastic
+force of steam, and Gren had shown that, at the temperature<span class='pagenum'><a name="Page_447" id="Page_447">[447]</a></span>
+of boiling water, the pressure of steam was equal
+to that of the atmosphere; Dalton, Ure, and others proved
+(1800-1818) that the law connecting temperatures and pressures
+of steam was expressed by a geometrical ratio; and
+Biot had already given an approximate formula, when
+Southern introduced another, which is still in use.</p>
+
+<p>The French Government established a commission in
+1823 to experiment with a view to the institution of legislation
+regulating the working of steam-engines and boilers;
+and this commission, MM. de Prony, Arago, Girard, and
+Dulong, determined quite accurately the temperatures of
+steam under pressures running up to twenty-four atmospheres,
+giving a formula for the calculation of the one
+quantity, the other being known. Ten years later, the Government
+of the United States instituted similar experiments
+under the direction of the Franklin Institute.</p>
+
+<p>The marked distinction between gases, like oxygen and
+hydrogen, and condensible vapors, like steam and carbonic
+acid, had been, at this time, shown by Cagniard de la Tour,
+who, in 1822, studied their behavior at high temperatures
+and under very great pressures. He found that, when a
+vapor was confined in a glass tube in presence of the same
+substance in the liquid state, as where steam and water were
+confined together, if the temperature was increased to a
+certain definite point, the whole mass suddenly became of
+uniform character, and the previously existing line of demarkation
+vanished, the whole mass of fluid becoming, as
+he inferred, gaseous. It was at about this time that Faraday
+made known his then novel experiments, in which gases
+which had been before supposed permanent were liquefied,
+simply by subjecting them to enormous pressures. He then
+also first stated that, above certain temperatures, liquefaction
+of vapors was impossible, however great the pressure.</p>
+
+<p>Faraday&#8217;s conclusion was justified by the researches of
+Dr. Andrews, who has since most successfully extended the
+investigation commenced by Cagniard de la Tour, and who has<span class='pagenum'><a name="Page_448" id="Page_448">[448]</a></span>
+shown that, at a certain point, which he calls the &#8220;critical
+point,&#8221; the properties of the two states of the fluid fade into
+each other, and that, at that point, the two become continuous.
+With carbonic acid, this occurs at 75 atmospheres,
+about 1,125 pounds per square inch, a pressure which would
+counterbalance a column of mercury 60 yards, or nearly as
+many metres, high. The temperature at this point is about
+90&deg; Fahr., or 31&deg; Cent. For ether, the temperature is 370&deg;
+Fahr., and the pressure 38 atmospheres; for alcohol, they
+are 498&deg; Fahr., and 120 atmospheres; and for bisulphide of
+carbon, 505&deg; Fahr., and 67 atmospheres. For water, the
+pressure is too high to be determined; but the temperature
+is about 775&deg; Fahr., or 413&deg; Cent.</p>
+
+<p>Donny and Dufour have shown that these normal properties
+of vapors and liquids are subject to modification by
+certain conditions, as previously (1818) noted by Gay-Lussac,
+and have pointed out the bearing of this fact upon the
+safety of steam-boilers. It was discovered that the boiling-point
+of water could be elevated far above its ordinary temperature
+of ebullition by expedients which deprive the
+liquid of the air usually condensed within its mass, and
+which prevent contact with rough or metallic surfaces.
+By suspension in a mixture of oils which is of nearly the
+same density, Dufour raised drops of water under atmospheric
+pressure to a temperature of 356&deg; Fahr.&mdash;180&deg; Cent.&mdash;the
+temperature of steam of about 150 pounds per square
+inch. Prof. James Thompson has, on theoretical grounds,
+indicated that a somewhat similar action may enable vapor,
+under some conditions, to be cooled below the normal temperature
+of condensation, without liquefaction.</p>
+
+<p>Fairbairn and Tate repeated the attempt to determine
+the volume and temperature of water at pressures extending
+beyond those in use in the steam-engine, and incomplete
+determinations have also been made by others.</p>
+
+<p>Regnault is the standard authority on these data. His
+experiments (1847) were made at the expense of the French<span class='pagenum'><a name="Page_449" id="Page_449">[449]</a></span>
+Government, and under the direction of the French Academy.
+They were wonderfully accurate, and extended through
+a very wide range of temperatures and pressures. The results
+remain standard after the lapse of a quarter of a century,
+and are regarded as models of precise physical work.<a name="FNanchor_112_112"
+id="FNanchor_112_112"></a><a href="#Footnote_112_112" class="fnanchor">[112]</a></p>
+
+<p>Regnault found that the total heat of steam is not constant,
+but that the latent heat varies, and that the sum of
+the latent and sensible heats, or the total heat, increases
+0.305 of a degree for each degree of increase in the sensible
+heat, making 0.305 the specific heat of saturated steam. He
+found the specific heat of superheated steam to be 0.4805.</p>
+
+<p>Regnault promptly detected the fact that steam was not
+subject to Boyle&#8217;s law, and showed that the difference is
+very marked. In expressing his results, he not only tabulated
+them but also laid them down graphically; he further
+determined exact constants for Biot&#8217;s algebraic expression,</p>
+
+<p class="ind10">log. <i>p</i> = <i>a</i> - <i>b</i>A<sup><i>x</i></sup> - <i>c</i>B<sup><i>x</i></sup>;</p>
+
+<p>making <i>x</i> = 20 + <i>t</i>&deg; Cent.; <i>a</i> = 6.264035; log. <i>b</i> =
+0.1397743; log. <i>c</i> = 0.6924351; log. A = <span class="bt">1</span>.9940493, and
+log. B = <span class="bt">1</span>.9983439; <i>p</i> is the pressure in atmospheres.
+Regnault, in the expression for the total heat, H = A + <i>bt</i>,
+determined on the centigrade scale <i>&#952;</i> = 606.5 + 0.305 <i>t</i> Cent.
+For the Fahrenheit scale, we have the following equivalent
+expressions:</p>
+
+<table class="ind10 left" summary="Formulae 449-1">
+
+<tr>
+<td>H</td>
+<td>&nbsp;=&nbsp;</td>
+<td colspan="4">1,113.44&deg;&nbsp;+&nbsp;0.305&nbsp;<i>t</i>&deg;&nbsp;Fahr.,&nbsp;if&nbsp;measured&nbsp;from&nbsp;0&deg;&nbsp;Fahr.</td>
+</tr>
+
+<tr>
+<td>&nbsp;</td>
+<td>&nbsp;=&nbsp;</td>
+<td>1,091.9&deg;&nbsp;</td>
+<td>+&nbsp;0.305&nbsp;(<i>t</i>&deg;&nbsp;-&nbsp;32)&nbsp;Fahr.,</td>
+<td rowspan="2"><span class="fsize180">&nbsp;}&nbsp;</span></td>
+<td>if&nbsp;measured&nbsp;from</td>
+</tr>
+
+<tr>
+<td>&nbsp;</td>
+<td>&nbsp;=&nbsp;</td>
+<td>1,081.94&deg;&nbsp;</td>
+<td>+&nbsp;0.305&nbsp;<i>t</i>&deg;&nbsp;Fahr.,</td>
+<td>the&nbsp;freezing-point.</td>
+</tr>
+
+</table>
+
+<p>For latent heat, we have:</p>
+
+<table class="ind10 left" summary="Formulae 449-2">
+
+<tr>
+<td>L</td>
+<td>&nbsp;=&nbsp;</td>
+<td>606.5&deg;&nbsp;</td>
+<td>-&nbsp;0.695&nbsp;<i>t</i>&deg;&nbsp;Cent.</td>
+</tr>
+
+<tr>
+<td>&nbsp;</td>
+<td>&nbsp;=&nbsp;</td>
+<td>1,091.7&deg;&nbsp;</td>
+<td>-&nbsp;0.695&nbsp;(<i>t</i>&deg;&nbsp;-&nbsp;32)&nbsp;Fahr.</td>
+</tr>
+
+<tr>
+<td>&nbsp;</td>
+<td>&nbsp;=&nbsp;</td>
+<td>1,113.94&deg;&nbsp;</td>
+<td>-&nbsp;0.695&nbsp;<i>t</i>&deg;&nbsp;Fahr.</td>
+</tr>
+
+</table>
+
+<p><span class='pagenum'><a name="Page_450" id="Page_450">[450]</a></span>Since Regnault&#8217;s time, nothing of importance has been
+done in this direction. There still remains much work to
+be done in the extension of the research to higher pressures,
+and under conditions which obtain in the operation of the
+steam-engine. The volumes and densities of steam require
+further study, and the behavior of steam in the engine is
+still but little known, otherwise than theoretically. Even
+the true value of Joule&#8217;s equivalent is not undisputed.</p>
+
+<p>Some of the most recent experimental work bearing
+directly upon the philosophy of the steam-engine is that of
+Hirn, whose determination of the value of the mechanical
+equivalent was less than two per cent. below that of Joule.
+Hirn tested by experiment, in 1853, and repeatedly up to
+1876, the analytical work of Rankine, which led to the conclusion
+that steam doing work by expansion must become
+gradually liquefied. Constructing a glass steam-engine
+cylinder, he was enabled to see plainly the clouds of mist
+which were produced by the expansion of steam behind the
+piston, where Regnault&#8217;s experiments prove that the steam
+should become drier and superheated, were no heat transformed
+into mechanical energy. As will be seen hereafter,
+this great discovery of Rankine is more important in its
+bearing upon the theory of the steam-engine than any made
+during the century. Hirn&#8217;s confirmation stands, in value,
+beside the original discovery. In 1858 Hirn confirmed the
+work of Mayer and Joule by determining the work done
+and the carbonic acid produced, as well as the increased
+temperature due to their presence, where men were set at
+work in a treadmill; he found the elevation of temperature
+to be much greater in proportion to gas produced when the
+men were resting than when they were at work. He thus
+proved conclusively the conversion of heat-energy into mechanical
+work. It was from these experiments that Helmholtz
+deduced the &#8220;modulus of efficiency&#8221; of the human
+machine at one-fifth, and concluded that the heart works
+with eight times the efficiency of a locomotive-engine, thus<span class='pagenum'><a name="Page_451" id="Page_451">[451]</a></span>
+confirming a statement of Rumford, who asserted the higher
+efficiency of the animal.</p>
+
+<p>Hirn&#8217;s most important experiments in this department
+were made upon steam-engines of considerable size, including
+simple and compound engines, and using steam sometimes
+saturated and sometimes superheated to temperatures
+as high, on some occasions, as 340&deg; Cent. He determined the
+work done, the quantity of heat entering, and the amount
+rejected from, the steam-cylinder, and thus obtained a
+coarse approximation to the value of the heat-equivalent.
+His figure varied from 296 to 337 kilogrammetres. But, in
+all cases, the loss of heat due to work done was marked,
+and, while these researches could not, in the nature of the
+case, give accurate quantitative results, they are of great
+value as qualitatively confirming Mayer and Joule, and
+proving the transformation of energy.</p>
+
+<p>Thus, as we have seen, experimental investigation and
+analytical research have together created a new science,
+and the philosophy of the steam-engine has at last been
+given a complete and well-defined form, enabling the intelligent
+engineer to comprehend the operation of the machine,
+to perceive the conditions of efficiency, and to look
+forward in a well-settled direction for further advances in
+its improvement and in the increase of its efficiency.</p>
+
+<p>A very concise <i>r&eacute;sum&eacute;</i> of the principal facts and laws
+bearing upon the philosophy of the steam-engine will form
+a fitting conclusion to this historical sketch.</p>
+
+<p>The term &#8220;energy&#8221; was first used by Dr. Young as the
+equivalent of the work of a moving body, in his hardly yet
+obsolete &#8220;Lectures on Natural Philosophy.&#8221;</p>
+
+<p>Energy is the capacity of a moving body to overcome
+resistance offered to its motion; it is measured either by
+the product of the mean resistance into the space through
+which it is overcome, or by the half-product of the mass of
+the body into the square of its velocity. Kinetic energy is
+the actual energy of a moving body; potential energy is<span class='pagenum'><a name="Page_452" id="Page_452">[452]</a></span>
+the measure of the work which a body is capable of doing
+under certain conditions which, without expending energy,
+may be made to affect it, as by the breaking of a cord by
+which a weight is suspended, or by firing a mass of explosive
+material. The British measure of energy is the foot-pound;
+the metric measure is the kilogrammetre.</p>
+
+<p>Energy, whether kinetic or potential, may be observable
+and due to mass-motion; or it may be invisible and due to
+molecular movements. The energy of a heavenly body or
+of a cannon-shot, and that of heat or of electrical action, are
+illustrations of the two classes. In Nature we find utilizable
+potential energy in fuel, in food, in any available head of
+water, and in available chemical affinities. We find kinetic
+energy in the motion of the winds and the flow of running
+water, in the heat-motion of the sun&#8217;s rays, in heat-currents
+on the earth, and in many intermittent movements of bodies
+acted on by applied forces, natural or artificial. The potential
+energy of fuel and of food has already been seen to
+have been derived, at an earlier period, from the kinetic
+energy of the sun&#8217;s rays, the fuel or the food being thus
+made a storehouse or reservoir of energy. It is also seen
+that the animal system is simply a &#8220;mechanism of transmission&#8221;
+for energy, and does not create but simply diverts
+it to any desired direction of application.</p>
+
+<p>All the available forms of energy can be readily traced
+back to a common origin in the potential energy of a universe
+of nebulous substance (chaos), consisting of infinitely
+diffused matter of immeasurably slight density, whose &#8220;energy
+of position&#8221; had been, since the creation, gradually
+going through a process of transformation into the several
+forms of kinetic and potential energy above specified,
+through intermediate methods of action which are usually
+still in operation, such as the potential energy of chemical
+affinity, and the kinetic forms of energy seen in solar radiation,
+the rotation of the earth, and the heat of its interior.</p>
+
+<p>The <i>measure</i> of any given quantity of energy, whatever<span class='pagenum'><a name="Page_453" id="Page_453">[453]</a></span>
+may be its form, is the product of the resistance which it
+is capable of overcoming into the space through which it
+can move against that resistance, i. e., by the product RS.
+Or it is measured by the equivalent expressions <span class="enum">1</span>&#8725;<span class="denom">2</span>MV<span class="enum">2</span>, or
+WV<span class="enum">2</span>/2<i>g</i>, in which W is the weight, M is the &#8220;mass&#8221; of matter
+in motion, V the velocity, and <i>g</i> the dynamic measure
+of the force of gravity, 32<span class="enum">1</span>&#8725;<span class="denom">6</span> feet, or 9.8 metres, per second.</p>
+
+<p>There are three great laws of energetics:</p>
+
+<p>1. The sum total of the energy of the universe is invariable.</p>
+
+<p>2. The several forms of energy are interconvertible,
+and possess an exact quantitative equivalence.</p>
+
+<p>3. The tendency of all forms of kinetic energy is continually
+toward reduction to forms of molecular motion,
+and to their final dissipation uniformly throughout space.</p>
+
+<p>The history of the first two of these laws has already
+been traced. The latter was first enunciated by Prof. Sir
+William Thomson in 1853. Undissipated energy is called
+&#8220;Entrophy.&#8221;</p>
+
+<p>The science of thermo-dynamics is, as has been stated, a
+branch of the science of energetics, and is the only branch
+of that science in the domain of the physicist which has
+been very much studied. This branch of science, which is
+restricted to the consideration of the relations of heat-energy
+to mechanical energy, is based upon the great fact
+determined by Rumford and Joule, and considers the behavior
+of those fluids which are used in heat-engines as the
+media through which energy is transferred from the one
+form to the other. As now accepted, it assumes the correctness
+of the hypothesis of the dynamic theory of fluids,
+which supposes their expansive force to be due to the motion
+of their molecules.</p>
+
+<p>This idea is as old as Lucretius, and was distinctly expressed
+by Bernouilli, Le Sage and Pr&eacute;vost, and Herapath.
+Joule recalled attention to this idea, in 1848, as explaining<span class='pagenum'><a name="Page_454" id="Page_454">[454]</a></span>
+the pressure of gases by the impact of their molecules upon
+the sides of the containing vessels. Helmholtz, ten years
+later, beautifully developed the mathematics of media composed
+of moving, frictionless particles, and Clausius has
+carried on the work still further.</p>
+
+<p>The general conception of a gas, as held to-day, including
+the vortex-atom theory of Thomson and Rankine,
+supposes all bodies to consist of small particles called molecules,
+each of which is a chemical aggregation of its ultimate
+parts or atoms. These molecules are in a state of
+continual agitation, which is known as heat-motion. The
+higher the temperature, the more violent this agitation;
+the total quantity of motion is measured as <i>vis viva</i> by the
+half-product of the mass into the square of the velocity of
+molecular movement, or in heat-units by the same product
+divided by Joule&#8217;s equivalent. In solids, the range of motion
+is circumscribed, and change of form cannot take place.
+In fluids, the motion of the molecules has become sufficiently
+violent to enable them to break out of this range,
+and their motion is then no longer definitely restricted.</p>
+
+<p>The laws of thermo-dynamics are, according to Rankine:</p>
+
+<p>1. Heat-energy and mechanical energy are mutually
+convertible, one British thermal unit being the equivalent
+in heat-energy of 772 foot-pounds of mechanical energy,
+and one metric <i>calorie</i> equal to 423.55 kilogrammetres of
+work.</p>
+
+<p>2. The energy due to the heat of each of the several
+equal parts into which a uniformly hot substance may be
+divided is the same; and the total heat-energy of the mass
+is equal to the sum of the energies of its parts.<a name="FNanchor_113_113"
+id="FNanchor_113_113"></a><a href="#Footnote_113_113" class="fnanchor">[113]</a></p>
+
+<p>It follows that the work performed by the transformation
+of the energy of heat, during any indefinitely small<span class='pagenum'><a name="Page_455" id="Page_455">[455]</a></span>
+variation of the state of a substance as respects temperature,
+is measured by the product of the absolute temperature
+into the variation of a &#8220;function,&#8221; which function is
+the rate of variation of the work so done with temperature.
+This function is the quantity called by Rankine the &#8220;heat-potential&#8221;
+of the substance for the given kind of work. A
+similar function, which comprehends the total heat-variation,
+including both heat transformed and heat needed to
+effect accompanying physical changes, is called the &#8220;thermo-dynamic
+function.&#8221; Rankine&#8217;s expression for the general
+equation of thermo-dynamics includes the latter, and is
+given by him as follows:</p>
+
+<p class="ind10">J<i>dh</i> = <i>d</i>H = <i>kd&#964;</i> + <i>&#964;d</i>F = <i>&#964;d&#966;</i>,</p>
+
+<p>in which J is Joule&#8217;s equivalent, <i>dh</i> the variation of total
+heat in the substance, <i>kd&#964;</i> the product of the &#8220;dynamic
+specific heat&#8221; into the variation of temperature, or the total
+heat demanded to produce other changes than a transformation
+of energy, and <i>&#964;d</i>F is the work done by the transformation
+of heat-energy, or the product of the absolute
+temperature, <i>&#964;</i>, into the differential of the heat-potential.
+<i>&#966;</i> is the thermo-dynamic function, and <i>&#964;d&#966;</i> measures the
+whole heat needed to produce, simultaneously, a certain
+amount of work or of mechanical energy, and, at the same
+time, to change the temperature of the working substance.</p>
+
+<p>Studying the behavior of gases and vapors, it is found
+that the work done when they are used, like steam, in heat-engines,
+consists of three parts:</p>
+
+<p>(<i>a.</i>) The change effected in the total actual heat-motion
+of the fluid.</p>
+
+<p>(<i>b.</i>) That heat which is expended in the production of
+internal work.</p>
+
+<p>(<i>c.</i>) That heat which is expended in doing the external
+work of expansion.</p>
+
+<p>In any case in which the total heat expended exceeds
+that due the production of work on external bodies, the excess<span class='pagenum'><a name="Page_456" id="Page_456">[456]</a></span>
+so supplied is so much added to the intrinsic energy of
+the substance absorbing it.</p>
+
+<p>The application of these laws to the working of steam
+in the engine is a comparatively recent step in the philosophy
+of the steam-engine, and we are indebted to Rankine
+for the first, and as yet only, extended and in any respect
+complete treatise embodying these now accepted principles.</p>
+
+<p>It was fifteen years after the publication of the first
+logical theory of the steam-engine, by Pambour,<a name="FNanchor_114_114" id="FNanchor_114_114"></a><a
+href="#Footnote_114_114" class="fnanchor">[114]</a> before
+Rankine, in 1859, issued the most valuable of all his works,
+&#8220;The Steam-Engine and other Prime Movers.&#8221; The work
+is far too abstruse for the general reader, and is even difficult
+reading for many accomplished engineers. It is excellent
+beyond praise, however, as a treatise on the thermo-dynamics
+of heat-engines. It will be for his successors the
+work of years to extend the application of the laws which
+he has worked out, and to place the results of his labors
+before students in a readily comprehended form.</p>
+
+<p>William J. Macquorn Rankine, the Scotch engineer and
+philosopher, will always be remembered as the author of
+the modern philosophy of the steam-engine, and as the
+greatest among the founders of the science of thermo-dynamics.
+His death, while still occupying the chair of engineering
+at the University of Glasgow, December 24, 1872,
+at the early age of fifty-two, was one of the greatest losses
+to science and to the profession which have occurred during
+the century.</p>
+
+<hr class="l05" />
+<div class="colleft">
+
+<div class="footnote"><p class="left"><a name="Footnote_103_103" id="Footnote_103_103"></a><a href="#FNanchor_103_103"><span class="label">[103]</span></a> Their estimate of the length of the Saros, or cycle of eclipses&mdash;over 19
+years&mdash;was &#8220;within 19<span class="enum">1</span>&#8725;<span class="denom">2</span> minutes
+of the truth.&#8221;&mdash;<span class="smcap">Draper.</span></p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_104_104" id="Footnote_104_104"></a><a href="#FNanchor_104_104"><span class="label">[104]</span></a> &#8220;History of Civilization in England,&#8221;
+vol. i., p. 208. London, 1868.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_105_105" id="Footnote_105_105"></a><a
+href="#FNanchor_105_105"><span class="label">[105]</span></a> &#8220;Philosophical Transactions,&#8221; 1798.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_106_106" id="Footnote_106_106"></a><a
+href="#FNanchor_106_106"><span class="label">[106]</span></a> This idea was not by any means original with Rumford. Bacon seems
+to have had the same idea; and Locke says, explicitly enough: &#8220;Heat is a
+very brisk agitation of the insensible parts of the object ... so that
+what in our sensation is heat, in the object is nothing but motion.&#8221;</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_107_107" id="Footnote_107_107"></a><a
+href="#FNanchor_107_107"><span class="label">[107]</span></a> The British heat-unit is the quantity of heat required to heat one
+pound of water 1&deg; Fahr. from the temperature of maximum density.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_108_108" id="Footnote_108_108"></a><a
+href="#FNanchor_108_108"><span class="label">[108]</span></a> Rankine
+gives 25,920 foot-pounds per minute&mdash;or 432 per second&mdash;for
+the average draught-horse in Great Britain, which is probably too high
+for Bavaria. The engineer&#8217;s &#8220;horse-power&#8221;&mdash;33,000 foot-pounds per
+minute&mdash;is far in excess of the average power of even a good draught-horse,
+which latter is sometimes taken as two-thirds the former.</p></div>
+</div>
+
+<div class="footnote"><p class="left"><a name="Footnote_109_109" id="Footnote_109_109"></a><a href="#FNanchor_109_109"><span
+class="label">[109]</span></a> <i>Vide</i> Tait&#8217;s admirable &#8220;Sketch of Thermodynamics,&#8221; second edition,
+Edinburgh, 1877.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_110_110" id="Footnote_110_110"></a><a
+href="#FNanchor_110_110"><span class="label">[110]</span></a> &#8220;New Experiments, Physico-Mechanical, etc., touching the Spring of
+Air,&#8221; 1662.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_111_111" id="Footnote_111_111"></a><a
+href="#FNanchor_111_111"><span class="label">[111]</span></a> &#8220;De la Nature de l&#8217;Air,&#8221; 1676.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_112_112" id="Footnote_112_112"></a><a
+href="#FNanchor_112_112"><span class="label">[112]</span></a> <i>See</i> Porter on the Steam-Engine
+Indicator for the best set of Regnault&#8217;s
+tables generally accessible.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_113_113" id="Footnote_113_113"></a><a
+href="#FNanchor_113_113"><span class="label">[113]</span></a> This uniformity is not seen where a substance is changing its physical
+state while developing its heat-energy, as occurs with steam doing work
+while expanding.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_114_114" id="Footnote_114_114"></a><a
+href="#FNanchor_114_114"><span class="label">[114]</span></a> &#8220;Th&eacute;orie de la Machine &agrave;
+Vapeur,&#8221; par le Chevalier F. M. G. de Pambour, Paris, 1844.</p></div>
+
+<hr class="c40" /><p class='pagenum'><a name="Page_457" id="Page_457">[457]</a></p>
+<h2><a name="CHAPTER_VIII" id="CHAPTER_VIII"></a>CHAPTER VIII.</h2>
+<h3><i>THE PHILOSOPHY OF THE STEAM-ENGINE.</i></h3>
+
+<hr class="c05" />
+<h4><span class="smcap">Its Application; its Teachings respecting the Construction of the Engine and its Improvement.</span></h4>
+<hr class="c05" />
+
+<div class="blockquot"><p>&#8220;Oftentimes an Uncertaintie hindered our going on so merrily, but by
+persevering the Difficultie was mastered, and the new Triumph gave
+stronger Heart unto us.&#8221;&mdash;<span class="smcap">Raleigh.</span></p></div>
+
+<div class="blockquot"><p>&#8220;If everything which we cannot comprehend is to be called an impossibility,
+how many are daily presented to our eyes! and in contemning as
+false that which we consider to be impossible, may we not be depreciating
+a giant&#8217;s effort to give an importance to our own weakness?&#8221;&mdash;<span class="smcap">Montaigne.</span></p></div>
+
+<div class="blockquot"><p>&#8220;They who aim vigorously at perfection will come nearer to it than
+those whose laziness or despondency makes them give up its pursuit from
+the feeling of its being unattainable.&#8221;&mdash;<span class="smcap">Chesterfield.</span></p></div>
+<hr class="c05" />
+
+<p>As has been already stated, the steam-engine is a machine
+which is especially designed to transform energy,
+originally dormant or potential, into active and usefully
+available kinetic energy.</p>
+
+<p>When, millions of years ago, in that early period which
+the geologists call the carboniferous, the kinetic energy of
+the sun&#8217;s rays, and of the glowing interior of the earth,
+was expended in the decomposition of the vast volumes of
+carbonic acid with which air was then charged, and in the
+production of a life-sustaining atmosphere and of the immense
+forests which then covered the earth with their almost<span class='pagenum'><a name="Page_458" id="Page_458">[458]</a></span>
+inconceivably luxuriant vegetation, there was stored up
+for the benefit of the human race, then uncreated, an inconceivably
+great treasure of potential energy, which we are
+now just beginning to utilize. This potential energy becomes
+kinetic and available wherever and whenever the
+powerful chemical affinity of oxygen for carbon is permitted
+to come into play; and the fossil fuel stored in our coal-beds
+or the wood of existing forests is, by the familiar process
+of combustion, permitted to return to the state of combination
+with oxygen in which it existed in the earliest geological
+periods.</p>
+
+<p>The philosophy of the steam-engine, therefore, traces
+the changes which occur from this first step, by which, in
+the furnace of the steam-boiler, this potential energy which
+exists in the tendency of carbon and oxygen to combine to
+form carbonic acid is taken advantage of, and the utilizable
+kinetic energy of heat is produced in equivalent amount,
+to the final application of resulting mechanical energy to
+machinery of transmission, through which it is usefully
+applied to the elevation of water, to the driving of mills
+and machinery of all kinds, or to the hauling of &#8220;lightning&#8221;
+trains on our railways, or to the propulsion of the
+Great Eastern.</p>
+
+<p>The kinetic heat-energy developed in the furnace of the
+steam-boiler is partly transmitted through the metallic
+walls which inclose the steam and water within the boiler,
+there to evaporate water, and to assume that form of energy
+which exists in steam confined under pressure, and is
+partly carried away into the atmosphere in the discharged
+gaseous products of combustion, serving, however, a useful
+purpose, <i>en route</i>, by producing the draught needed to keep
+up combustion.</p>
+
+<p>The steam, with its store of heat-energy, passes through
+tortuous pipes and passages to the steam-cylinder of the
+engine, losing more or less heat on the way, and there expands,
+driving the piston before it, and losing heat by the<span class='pagenum'><a name="Page_459" id="Page_459">[459]</a></span>
+transformation of that form of energy while doing mechanical
+work of equivalent amount. But this steam-cylinder is
+made of metal, a material which is one of the best conductors
+of heat, and therefore one of the very worst possible
+substances with which to inclose anything as subtile and
+difficult of control as the heat pervading a condensible
+vapor like steam. The process of internal condensation and
+re&euml;vaporation, which is the great enemy of economical
+working, thus has full play, and is only partly checked by
+the heat from the steam-jacket, which, penetrating the cylinder,
+assists by keeping up the temperature of the internal
+surface and checking the first step, condensation, which is
+an essential preliminary to the final waste by re&euml;vaporation.
+The piston, too, is of metal, and affords a most excellent
+way of exit for the heat escaping to the exhaust side.</p>
+
+<p>Finally, all unutilized heat rejected from the steam-cylinder
+is carried away from the machine, either by the water
+of condensation, or, in the non-condensing engine, by the
+atmosphere into which it is discharged.</p>
+
+<p>Having traced the method of operation of the steam-engine,
+it is easy to discover what principles are comprehended
+in its philosophy, to learn what are known facts
+bearing upon its operation, and to determine what are the
+directions in which improvement must take place, what are
+the limits beyond which improvement cannot possibly be
+carried, and, in some directions, to determine what is the
+proper course to pursue in effecting improvements. The
+general direction of change in the past, as well as at present,
+is easily seen, and it may usually be assumed that there
+will be no immediate change of direction in a course which
+has long been preserved, and which is well defined. We
+may, therefore, form an idea of the probable direction in
+which to look for improvement in the near future.</p>
+
+<p>Reviewing the operations which go on in this machine
+during the process of transformation of energy which has
+been outlined, and studying it more in detail, we may deduce<span class='pagenum'><a name="Page_460" id="Page_460">[460]</a></span>
+the principles which govern its design and construction,
+guide us in its management, and determine its efficiency.</p>
+
+<p>In the furnace of the boiler, the quantity of heat developed
+in available form is proportional to the amount of
+fuel burned. It is available in proportion to the temperature
+attained by the products of combustion; were this
+temperature no higher than that of the boiler, the heat
+would all pass off unutilized. But the temperature produced
+by a given quantity of heat, measured in heat-units,
+is greater as the volume of gas heated is less. It follows
+that, at this point, therefore, the fuel should be perfectly
+consumed with the least possible air-supply, and the least
+possible abstraction of heat before combustion is complete.
+High temperature of furnace, also, favors complete combustion.
+We hence conclude that, in the steam-boiler furnace,
+fuel should be burned completely in a chamber having non-conducting
+walls, and with the smallest air-supply compatible
+with thorough combustion; and, further, that the air
+should be free from moisture, that greatest of all absorbents
+of heat, and that the products of combustion should
+be removed from the furnace before beginning to drain
+their heat into the boiler. A fire-brick furnace, a large
+combustion-chamber with thorough intermixture of gases
+within it, good fuel, and a restricted and carefully-distributed
+supply of air, seem to be the conditions which meet
+these requisites best.</p>
+
+<p>The heat generated by combustion traverses the walls
+which separate the gases of the furnace from the steam and
+water confined within the boiler, and is then taken up by
+those fluids, raising their temperature from that of the entering
+&#8220;feed-water&#8221; to that due the steam-pressure, and
+expanding the liquid into steam occupying a greatly-increased
+volume, thus doing a certain amount of work, besides
+increasing temperature. The extent to which heat
+may thus be usefully withdrawn from the furnace-gases
+depends upon the conductivity of the metallic wall, the<span class='pagenum'><a name="Page_461" id="Page_461">[461]</a></span>
+rate at which the water will take heat from the metal, and
+the difference of temperature on the two sides of the metal.
+Extended &#8220;heating-surface,&#8221; therefore, a metal of high conducting
+power, and a maximum difference of temperature
+on the two sides of the separating wall of metal, are the
+essential conditions of economy here. The heating-surface
+is sometimes made of so great an area that the temperature
+of the escaping gases is too low to give good chimney-draught,
+and a &#8220;mechanical draught&#8221; is resorted to, revolving
+&#8220;fan-blowers&#8221; being ordinarily used for its production.
+It is most economical to adopt this method. The
+steam-boiler is generally constructed of iron&mdash;sometimes,
+but rarely, of cast-iron, although &#8220;steel,&#8221; where not hard
+enough to harden or temper, is better in consequence of its
+greater strength and homogeneousness of structure, and its
+better conductivity. The maximum conductivity of flow
+of heat for any given material is secured by so designing
+the boiler as to secure rapid, steady, and complete circulation
+of the water within it. The maximum rapidity of
+transfer throughout the whole area of heating-surface is
+secured, usually, by taking the feed-water into the boiler
+as nearly as possible at the point where the gases are discharged
+into the chimney-flue, withdrawing the steam nearer
+the point of maximum temperature of flues, and securing
+opposite directions of flow for the gases on the one side
+and the water on the other. Losses of heat from the boiler,
+by conduction and radiation to surrounding bodies, are
+checked as far as possible by non-conducting coverings.</p>
+
+<p>The mechanical equivalent of the heat generated in the
+boiler is easily calculated when the conditions of working
+are known. A pound of pure carbon has been found to be
+capable of liberating by its perfect combustion, resulting in
+the formation of carbonic acid, 14,500 British thermal units,
+equivalent to 14,500 &times; 772 = 11,194,000 foot-pounds of work,
+and, if burned in one hour, to <span class="enum">11194000</span>&#8725;<span class="denom">1980000</span> = 5.6 horse-power.
+In other words, with perfect utilization, but <span class="enum">10</span>&#8725;<span class="denom">56</span> = 0.177,
+or<span class='pagenum'><a name="Page_462" id="Page_462">[462]</a></span>
+about one-sixth, of a pound of carbon would be needed
+per hour for each horse-power of work done. But even
+good coal is not nearly all carbon, and has but about nine-tenths
+this heat-producing power, and it is usually rated as
+yielding about 10,000,000 foot-pounds of work per pound.
+The evaporative power of pure carbon being rated at 15
+pounds of water, that of good coal may be stated at 13<span class="enum">1</span>&#8725;<span class="denom">2</span>.
+In metric measures, one gramme of good coal should evaporate
+about 13<span class="enum">1</span>&#8725;<span class="denom">2</span> grammes of water from the boiling-point,
+producing the equivalent of about 3,000,000 kilogrammetres
+of work from the 7,272 <i>calories</i> of heat thus generated. A
+gramme of pure carbon generates in its combustion 8,080
+<i>calories</i> of heat. Per hour and per horse-power, 0.08, or
+less than one-twelfth, of a kilogram of carbon burned
+per hour evolves heat-energy equal to one horse-power.</p>
+
+<p>Of the coal burned in a steam-boiler, it rarely happens
+that more than three-fourths is utilized in making steam;
+7,500,000 foot-pounds (1,036,898 kilogrammetres) is, therefore,
+as much energy as is usually sent to the engine per
+pound of good coal burned in the steam-boiler. The
+&#8220;efficiency&#8221; of a good steam-boiler is therefore usually
+not far from 0.75 as a maximum. Rankine estimates this
+quantity for ordinary boilers of good design and with
+chimney-draught at</p>
+
+<table class="ind10" summary="formula_462">
+
+<tr>
+<td rowspan="2">E&nbsp;=&nbsp;</td>
+<td colspan="2" class="center bb">0.92</td>
+<td rowspan="2">&nbsp;;</td>
+</tr>
+
+<tr>
+<td>1&nbsp;+&nbsp;0.5</td>
+<td><table class="fsize80" style="line-height: .5em;" summary="F/S"><tr>
+<td class="bb">&nbsp;F&nbsp;</td></tr><tr><td class="center">S</td></tr></table></td>
+</tr>
+
+</table>
+
+<p>in which <span class="enum">F</span>&#8725;<span class="denom">S</span> is the ratio of weight of fuel burned per square
+foot of grate to the ratio of heating to grate surface; this is
+a formula of fairly close approximation for general practice.</p>
+
+<p>The steam in the engine first drives the piston some distance
+before the induction or steam valve is closed, and it
+then expands, doing work, and condensing in proportion to
+work done as the expansion proceeds, until it is finally released
+by the opening of the exhaust or eduction valve.
+Saturated steam is modified in its action by a process which<span class='pagenum'><a name="Page_463" id="Page_463">[463]</a></span>
+has already been described, condensing at the beginning
+and re&euml;vaporating at the end of the stroke, thus carrying
+into the condenser considerable quantities of heat which
+should have been utilized in the development of power.
+Whether this operation takes place in one cylinder or in
+several is only of importance in so far as it modifies the losses
+due to conduction and radiation of heat, to condensation
+and re&euml;vaporation of steam, and to the friction of the
+machine. It has already been seen how these losses are
+modified by the substitution of the compound for the single-cylinder
+engine.</p>
+
+<p>The laws of thermo-dynamics teach, as has been stated,
+that the proportion of the heat-energy contained in the steam
+or other working fluid which may be transformed into
+mechanical energy is a fraction <span class="enum">(H<sub>1</sub> - H<sub>2</sub>)</span>&#8725;<span
+class="denom">H<sub>1</sub></span>, of the total, in
+which H<span class="denom">1</span> and H<span class="denom">2</span> are the quantities of heat contained in the
+steam at the beginning and at the end of its operation,
+measuring from the absolute zero of heat-motion. In perfect
+gases,</p>
+
+<table class="center ind10" summary="Formula_463">
+
+<tr>
+<td class="bb">&nbsp;H<span class="denom">1</span>&nbsp;-&nbsp;H<span class="denom">2</span>&nbsp;</td>
+<td rowspan="2">&nbsp;=&nbsp;</td>
+<td class="bb"><span class="fsize125">&#964;</span><span class="denom">1</span>&nbsp;-&nbsp;<span
+class="fsize125">&#964;</span><span class="denom">2</span></td>
+<td rowspan="2">&nbsp;=&nbsp;</td>
+<td class="bb">T<span class="denom">1</span>&nbsp;-&nbsp;T<span class="sub">2</span></td>
+<td rowspan="2">&nbsp;;</td>
+</tr>
+
+<tr>
+<td>H<span class="sub">1</span></td>
+<td><span class="fsize125">&#964;</span><span class="sub">1</span></td>
+<td>T<span class="sub">1</span> + 461.2&deg; Fahr.</td>
+</tr>
+
+</table>
+
+<p>but in imperfect gases, and especially in vapors which, like
+steam, condense, or otherwise change their physical state,
+this equality may still exist, <span class="enum">(H<span class="sub">1</span> - H<span class="sub">2</span>)</span>&#8725;<span
+class="denom">H<span class="sub">1</span></span> = <span
+class="enum">(&#964;<span class="sub">1</span> - &#964;<span class="sub">2</span>)</span>&#8725;<span
+class="denom">&#964;<span class="sub">1</span></span>; and the
+fluid is equally efficient with the perfect gas as a working
+substance in a heat-engine. In any case it is seen that the
+efficiency is greatest when the whole of the heat is received
+at the maximum and rejected at the minimum attainable
+temperatures.</p>
+
+<p>Assuming this expression strictly accurate, a hot-air
+engine working from 413.6&deg; Fahr, or 874.8&deg; absolute temperature,
+down to 122&deg; Fahr, or 583.2&deg; absolute, should have
+an efficiency of 0.263, transforming that proportion of<span class='pagenum'><a name="Page_464" id="Page_464">[464]</a></span>
+available heat into mechanical work. The engines of the
+steamer Ericsson closely approached this figure, and gave a
+horse-power for each 1.87 pound of coal burned per hour.</p>
+
+<p>Steam expands in the steam-cylinder quite differently
+under different circumstances. If no heat is either communicated
+to it or abstracted from it, however, it expands in
+an hyperbolic curve, losing its tension much more rapidly
+than when expanded without doing work, in consequence
+both of its change of volume and its condensation. The
+algebraic expression for this method of expansion is, according
+to Rankine, PV<span class="enum">1.111</span> = C, a constant, or, according to
+other authorities, from PV<span class="enum">1.135</span> = C to PV<span class="enum">1.140</span> = C. The
+greater the value of the exponent of V, the greater the efficiency
+of the fluid between any two temperatures. The
+maximum value has been found to be given where the
+steam is saturated, but perfectly dry, at the commencement
+of its expansion. The loss due to condensation on the
+cooled interior surface of the cylinder at the commencement
+of the stroke and the subsequent re&euml;vaporation as
+expansion progresses is least when the cylinder is kept hot
+by its steam-jacket and when least time is given during
+the stroke for this transfer of heat between the metal and
+the vapor.</p>
+
+<p>It may be said that, all things considered, therefore,
+losses of heat in the steam-cylinder are least when the steam
+enters dry, or moderately superheated, where the interior
+surfaces are kept hottest by the steam-jacket or by the
+hot-air jacket sometimes used, and where piston-speed and
+velocity of rotation are highest.<a name="FNanchor_115_115" id="FNanchor_115_115"></a><a
+href="#Footnote_115_115" class="fnanchor">[115]</a> The best of compound
+engines, using steam of seventy-five pounds pressure and
+condensing, usually require about two pounds of coal per
+hour&mdash;20,000,000 foot-pounds of energy at the furnace&mdash;to
+develop a horse-power, i. e., about ten times the heat-equivalent<span class='pagenum'><a name="Page_465" id="Page_465">[465]</a></span>
+of the mechanical work which they accomplish.
+Were the steam to expand like the permanent gases, they
+would have a theoretical efficiency of about one-quarter;
+actually, the efficiency is only one-tenth. The steam-engine,
+therefore, utilizes about two-fifths the heat-energy theoretically
+available with the best type of engine in general
+use. By far the greater part, nearly all, in fact, of the nine-tenths
+wasted is rejected in the exhaust steam, and can only
+be saved by some such method as is hereafter to be suggested
+of retaining that heat and returning it to the boiler.</p>
+
+<p>The mechanical power which has now been communicated
+to the mechanism of the engine by the transfer of the
+kinetic energy of the hot steam to the piston is finally usefully
+applied to whatever &#8220;mechanism of transmission&#8221;
+forms the connection with the machinery driven by the engine.
+In this transfer, there is some loss in the engine itself,
+by friction. This is an extremely variable amount, and
+it can be made very small by skillful design and good workmanship
+and management. It may be taken at one-half
+pound per square inch of piston for good engines of 100
+horse-power and upward, but is often several pounds in very
+small engines. It is least when the rubbing surfaces are of
+different materials, but both of smooth, hard, close-grained
+metal, well lubricated, and where advantage is taken of any
+arrangement of parts which permits the equilibration of
+pressure, as on the shaft-bearings of double and triple engines.
+The friction of a steam-engine of large size and
+good design is usually between five and seven per cent. of
+its total power. It increases rapidly as the size of engine
+decreases.</p>
+
+<p>Having now traced somewhat minutely the growth of
+the steam-engine from the beginning of the Christian era to
+the present time, having rapidly outlined the equally gradual,
+though intermittent, growth of its philosophy, and having
+shown how the principles of science find application in the
+operation of this wonderful machine, we are now prepared<span class='pagenum'><a name="Page_466" id="Page_466">[466]</a></span>
+to study the conditions which control the intelligent designer,
+and to endeavor to learn what are the lessons taught us
+by science and by experience in regard to the essential requisites
+of efficient working of steam and economy in the
+consumption of fuel. We may even venture to point out
+definitely the direction in which improvement is now progressing
+as indicated by a study of these requisites, and may
+be able to perceive the natural limits to such progress, and
+possibly to conjecture what must be the character of that
+change of type which only can take the engineer beyond
+the limit set to his advance so long as he is confined to the
+construction of the present type of engine.</p>
+
+<p>First, we must consider the question: <i>What is the
+problem, stated precisely and in its most general form, that
+engineers have been here attempting to solve?</i></p>
+
+<p>After stating the problem, we will examine the record
+with a view to determine what direction the path of improvement
+has taken hitherto, to learn what are the conditions
+of efficiency which should govern the construction of
+the modern steam-engine, and, so far as we may judge the
+future by the past, by inference, to ascertain what appears
+to be the proper course for the present and for the immediate
+future. Still further, we will inquire, what are the
+conditions, physical and intellectual, which best aid our
+progress in perfecting the steam-engine.</p>
+
+<p>This most important problem may be stated in its most
+general, yet definite, form as follows:</p>
+
+<p><i>To construct a machine which shall, in the most perfect
+manner possible, convert the kinetic energy of heat into
+mechanical power, the heat being derived from the combustion
+of fuel, and steam being the receiver and the conveyer
+of that heat.</i></p>
+
+<p>The problem, as we have already seen, embodies two
+distinct and equally important inquiries:</p>
+
+<p>The first: What are the scientific principles involved in
+the problem as stated?</p>
+
+<p><span class='pagenum'><a name="Page_467" id="Page_467">[467]</a></span>The second: How shall a machine be constructed that
+shall most efficiently embody, and accord with, not only
+those scientific principles, but also all of those principles of
+engineering practice that so vitally affect the economical
+value of every machine?</p>
+
+<p>The one question is addressed to the man of science, the
+other to the engineer. They can be satisfactorily answered,
+even so far as our knowledge at present permits, after studying
+with care the scientific principles involved in the theory
+of the steam-engine under the best light that science can
+afford us, and by a careful study of the various steps of improvement
+that have taken place and of accompanying variations
+of structure, analyzing the effect of each change, and
+tracing the reasons for them.</p>
+
+<p>The theory of the steam-engine is too important and
+too extensive a subject to be satisfactorily treated here in
+even the most concise possible manner. I can only attempt
+a plain statement of the course which seems to be pointed
+out by science as the proper one to pursue in the endeavor
+to increase the economical efficiency of steam-engines.</p>
+
+<p>The teachings of science indicate that <i>success in economically
+deriving mechanical power from the energy of heat-motion
+will, in all cases, be the greater as we work between
+more widely separated limits of temperature, and as we
+more perfectly provide against losses by dissipation of heat
+in directions in which it is unavailable for the production
+of power</i>.</p>
+
+<p>Scientific research, as we have seen, has proved that, in
+all known varieties of heat-engine, a large loss of effect is
+unavoidable from the fact that we cannot, in the ordinary
+steam-engine, reduce the lower limit of temperature, in
+working, below a point which is far above the absolute
+zero of temperature&mdash;far above that point at which bodies
+have no heat-motion. The point corresponding to the mean
+temperature of the surface of the earth is above the ordinary
+lower limit.</p>
+
+<p><span class='pagenum'><a name="Page_468" id="Page_468">[468]</a></span>The higher the temperature of the steam when it enters
+the steam cylinder, and the lower that which it reaches before
+the exhaust occurs, the greater, science tells us, will be
+our success, provided we at the same time avoid waste of
+heat and power.</p>
+
+<p>Now, looking back over the history of the steam-engine,
+we may briefly note the prominent improvements and the
+most striking changes of form, and may thus endeavor to
+obtain some idea of the general direction in which we are
+to look for further advance.</p>
+
+<p>Beginning with the machine of Porta, at which point we
+may first take up an unbroken thread, it will be remembered
+that we there found a single vessel performing the functions
+of all the parts of a modern pumping-engine; it was, at
+once, boiler, steam-cylinder, and condenser, as well as both
+a lifting and a forcing pump.</p>
+
+<p>The Marquis of Worcester divided the engine into two
+parts, using a separate boiler.</p>
+
+<p>Savery duplicated that part of the engine of Worcester
+which performed the several parts of pump, steam-cylinder,
+and condenser, and added the use of water to effect rapid
+condensation, perfecting, so far as it was ever perfected, the
+steam-engine as a simple machine.</p>
+
+<p>Newcomen and Calley next separated the pump from
+the steam-engine proper, producing the modern steam-engine&mdash;the
+engine as a train of mechanism; and in their engine,
+as in Savery&#8217;s, we noticed the use of surface condensation
+first, and subsequently that of the jet thrown into the
+midst of the steam to be condensed.</p>
+
+<p>Watt finally effected the crowning improvements, and
+completed the movement o&pound; &#8220;differentiation&#8221; by separating
+the condenser from the steam-cylinder. Here this process
+of change ceased, the several important operations of the
+steam-engine now being conducted each in a separate vessel.
+The boiler furnished the steam, the cylinder derived from it
+mechanical power, and it was finally condensed in a separate<span class='pagenum'><a name="Page_469" id="Page_469">[469]</a></span>
+vessel, while the power which had been obtained from it in
+the steam-cylinder was transmitted through still other parts,
+to the pumps, or wherever work was to be done.</p>
+
+<p>Watt, also, took the initiative in another direction. He
+continually increased the efficiency of the machine by improving
+the proportions of its parts and the character of its
+workmanship, thus making it possible to render available
+many of those improvements in detail upon which effectiveness
+is so greatly dependent and which are only useful when
+made by a skillful workman.</p>
+
+<p>Watt and his contemporaries also commenced that movement
+toward higher pressures of steam and greater expansion
+which has been the most striking feature noticed in the
+progress of steam-engineering since his time. Newcomen
+used steam of barely more than atmospheric pressure and
+raised 105,000 pounds of water one foot high with a pound
+of coal consumed. Smeaton raised the pressure somewhat
+and increased the duty considerably. Watt started with a
+duty double that of Newcomen and raised it to 320,000
+foot-pounds per pound of coal, with steam at 10 pounds
+pressure. To-day, Cornish engines of the same general plan
+as those of Watt, but worked with 40 to 60 pounds of steam
+and expanding three or four times, do a duty probably
+averaging, with the better class of engines, 600,000 foot-pounds
+per pound of coal. The compound pumping-engine
+runs the figure up to above 1,000,000.</p>
+
+<p>The increase in steam-pressure and in expansion since
+Watt&#8217;s time has been accompanied by a very great improvement
+in workmanship&mdash;a consequence, very largely,
+of the rapid increase in perfection, and in the wide range
+of adaptation of machine-tools&mdash;by higher skill and intelligence
+in designing engines and boilers, by increased piston-speed,
+greater care in obtaining dry steam, and in keeping
+it dry until thrown out of the cylinder, either by steam-jacketing
+or by superheating, or both combined; it has
+further been accompanied by a greater attention to the important<span class='pagenum'><a name="Page_470" id="Page_470">[470]</a></span>
+matter of providing carefully against losses by
+radiation and conduction of heat. We use, finally, the
+compound or double-cylinder engine for the purpose of saving
+some of the heat usually lost in internal condensation
+and re&euml;vaporation, and precipitation of condensed vapor
+from great expansion.</p>
+
+<p>It is evident that, although there is a limit, tolerably
+well defined, in the scale of temperature, below which we
+cannot expect to pass, a degree gained in approaching this
+lower limit is more remunerative than a degree gained in
+the range of temperature available by increasing temperatures.<a name="FNanchor_116_116" id="FNanchor_116_116"></a><a
+href="#Footnote_116_116" class="fnanchor">[116]</a></p>
+
+<p>Hence the attempt made by the French inventor, Du
+Trembly, about the year 1850, and by other inventors since,
+to utilize a larger proportion of heat by approaching more
+closely the lower limit, was in accordance with known scientific
+principles.</p>
+
+<p>We may summarize the result of our examination of the
+growth of the steam-engine thus:</p>
+
+<p><i>First.</i> The process of improvement has been one, primarily,
+of &#8220;differentiation;&#8221;<a name="FNanchor_117_117" id="FNanchor_117_117"></a><a
+href="#Footnote_117_117" class="fnanchor">[117]</a> the number of parts has been
+continually increased; while the work of each part has been
+simplified, a separate organ being appropriated to each process
+in the cycle of operations.</p>
+
+<p><i>Secondly.</i> A kind of secondary process of differentiation<span class='pagenum'><a name="Page_471" id="Page_471">[471]</a></span>
+has, to some extent, followed the completion of the
+primary one, in which secondary process one operation is
+conducted partly in one and partly in another portion of the
+machine. This is illustrated by the two cylinders of the
+compound engine and by the duplication noticed in the
+binary engine.</p>
+
+<p><i>Thirdly.</i> The direction of improvement has been marked
+by a continual increase of steam-pressure, greater expansion,
+provision for obtaining dry steam, high piston-speed, careful
+protection against loss of heat by conduction or radiation,
+and, in marine engines, by surface condensation.</p>
+
+<p>The direction which improvement seems now to be taking,
+and the proper direction, as indicated by an examination
+of the principles of science, as well as by our review of the
+steps already taken, would seem to be: working between
+the widest attainable limits of temperature.</p>
+
+<p>Steam must enter the machine at the highest possible
+temperature, must be protected from waste, and must retain,
+at the moment before exhaust, the least possible amount of
+heat. He whose inventive genius, or mechanical skill, contributes
+to effect either the use of higher steam with safety
+and without waste, or the reduction of the temperature of
+discharge, confers a boon upon mankind.</p>
+
+<p>In detail: In the engine, the tendency is, and may probably
+be expected to continue, in the near future at least,
+toward higher steam-pressure, greater expansion in more
+than one cylinder, steam-jacketing, superheating, a careful
+use of non-conducting protectors against waste, and the
+adoption of still higher piston-speeds.</p>
+
+<p>In the boiler: more complete combustion without excess
+of air passing through the furnace, and more thorough absorption
+of heat from the furnace-gases. The latter will
+probably be ultimately effected by the use of a mechanically
+produced draught, in place of the far more wasteful
+method of obtaining it by the expenditure of heat in the
+chimney.</p>
+
+<p><span class='pagenum'><a name="Page_472" id="Page_472">[472]</a></span>In construction we may anticipate the use of better materials,
+and more careful workmanship, especially in the
+boiler, and much improvement in forms and proportions of
+details.</p>
+
+<p>In management, there is a wide field for improvement,
+which improvement we may feel assured will rapidly take
+place, as it has now become well understood that great care,
+skill, and intelligence are important essentials to the economical
+management of the steam-engine, and that they
+repay, liberally, all of the expense in time and money that
+is requisite to secure them.</p>
+
+<p>In attempting improvements in the directions indicated,
+it would be the height of folly to assume that we have
+reached a limit in any one of them, or even that we have
+approached a limit. If further progress seems checked by
+inadequate returns for efforts made, in any case, to advance
+beyond present practice, it becomes the duty of the
+engineer to detect the cause of such hinderance, and, having
+found it, to remove it.</p>
+
+<p>A few years ago, the movement toward the expansive
+working of high steam was checked by experiments seeming
+to prove positive disadvantage to follow advance beyond
+a certain point. A careful revision of results, however,
+showed that this was true only with engines built, as
+was then common, in utter disregard of all the principles
+involved in such a use of steam, and of the precautions
+necessary to be taken to insure the gain which science
+taught us should follow. The hinderances are mechanical,
+and it is for the engineer to remove them.</p>
+
+<p>The last remark is especially applicable to the work of
+the engineer who is attempting to advance in the direction
+in which, as already intimated, an unmistakable revolution
+is now progressing, the modification of the modern steam-engine
+to adapt it safely and successfully to run at the
+high piston-speed, and great velocity of rotation which have
+been already attained and which must undoubtedly be<span class='pagenum'><a name="Page_473" id="Page_473">[473]</a></span>
+greatly exceeded in the future. As there is no known and
+definite limit to the economical increase of speed, and as
+the limit set by practical conditions is continually being set
+farther back as the builder acquires greater skill and attains
+greater accuracy of workmanship and the power to
+insure greater rigidity of parts and durability of wearing
+surfaces, we must anticipate a continued and indefinite
+progress in this direction&mdash;a progress which must evidently
+be of advantage, whatever may be the direction that other
+changes may take.</p>
+
+<p>It is evident that this adaptation of the steam-engine to
+great speed of piston is the work now to be done by the
+engineer. The requisites to success are obvious, and may be
+concisely stated as follows:</p>
+
+<p>1. Extreme accuracy in proportions.</p>
+
+<p>2. Perfect accuracy in fitting parts to each other.</p>
+
+<p>3. Absolute symmetry of journals.</p>
+
+<p>4. Ample area and maximum durability of rubbing surfaces.</p>
+
+<p>5. Perfect certainty of an ample and continuous lubrication.</p>
+
+<p>6. A nicely calculated and adjusted balance of reciprocating
+parts.</p>
+
+<p>7. Security against injury by shock, whether due to the
+presence of water in the cylinder or to looseness of running
+parts.</p>
+
+<p>8. A &#8220;positive-motion&#8221; cut-off gear.</p>
+
+<p>9. A powerful but sensitive and accurately-working
+governor determining the degree of expansion.<a name="FNanchor_118_118" id="FNanchor_118_118"></a><a
+href="#Footnote_118_118" class="fnanchor">[118]</a></p>
+
+<p><span class='pagenum'><a name="Page_474" id="Page_474">[474]</a></span>10. Well-balanced valves and an easy-working valve-gear.</p>
+
+<p>11. Small volume of &#8220;dead-space,&#8221; or &#8220;clearance,&#8221; and
+properly adjusted &#8220;compression.&#8221;</p>
+
+<p>It would seem sufficiently evident that the engine with
+detachable (&#8220;drop&#8221;) cut-off valve-gear must, sooner or later,
+become an obsolete type, although the substitution of springs
+or of steam-pressure for gravity in the closing of the detached
+valve may defer greatly this apparently inevitable
+change. The &#8220;engine of the future&#8221; will not probably be
+a &#8220;drop cut-off engine.&#8221;</p>
+
+<p>As regards the construction of the engine as a piece of
+mechanism, the principles and practice of good engineering
+are precisely the same, whether applied in the designing of
+the compound or of the ordinary type of steam-engine.
+The proportioning of the two machines to each other in
+such manner as to form an effective whole, by procuring
+approximately equal amounts of work from both, is the
+only essential peculiarity of compound-engine design which
+calls for especial care, and the method of securing success
+in practice may be stated to be, for both forms of engines,
+as follows:</p>
+
+<p>1. A good design, by which is meant&mdash;</p>
+
+<p><i>a.</i> Correct proportions, both in general dimensions and
+in arrangement of parts, and proper forms and sizes of details
+to withstand safely the forces which may be expected
+to come upon them.</p>
+
+<p><i>b.</i> A general plan which embodies the recognized practice
+of good engineering.</p>
+
+<p><i>c.</i> Adaptation to the specific work which it is intended
+to perform, in size and in efficiency. It sometimes happens
+that good practice dictates the use of a comparatively uneconomical
+design.</p>
+
+<p>2. Good construction, by which is meant&mdash;</p>
+
+<p><i>a.</i> The use of good material.</p>
+
+<p><i>b.</i> Accurate workmanship.</p>
+
+<p><i>c.</i> Skillful fitting and a proper &#8220;assemblage&#8221; of parts.</p>
+
+<p><span class='pagenum'><a name="Page_475" id="Page_475">[475]</a></span>3. Proper connection with its work, that it may do that
+work under the conditions assumed in its design.</p>
+
+<p>4. Skillful management by those in whose hands it is
+placed.</p>
+
+<p><i>In general</i>, it may be stated that, to secure maximum
+economical efficiency, steam should be worked at as high a
+pressure as possible, and the expansion should be fixed as
+nearly as possible at the point of maximum economy for
+that pressure. In general, the number of times which the
+volume of steam may be expanded in the standard single-cylinder,
+high-pressure engine with maximum economy, is
+not far from <span class="enum">1</span>&#8725;<span class="denom">2</span>&#8730;<span class="bt">P</span>,
+where P is the pressure in pounds per
+square inch; it rarely exceeds 0.75&#8730;<span class="bt">P</span>. This may be exceeded
+in double-cylinder engines. It is even more disadvantageous
+to cut off too short than to &#8220;&#8216;follow&#8217; too far.&#8221;
+With considerable expansion, steam-jacketing and moderate
+superheating should be adopted, to prevent excessive
+losses by internal condensation and re&euml;vaporation; and
+expansion should take place in double cylinders, to avoid
+excessive weight of parts, irregularity of motion, and great
+loss by friction.</p>
+
+<p>To secure this vitally important economy, it is advisable
+to seek some practicable method of lining the cylinder with
+a non-conducting material. This plan, as has been seen,
+was adopted by Smeaton, in constructing Newcomen engines
+a century ago. Smeaton used wood on his pistons,
+and Watt tried wood as a material for steam-cylinder linings.
+That material is too perishable at temperatures now
+common, and no metal has yet been substituted, or even
+discovered, which answers the same purpose. The loss will
+also be reduced by increasing the speed of rotation and velocity
+of piston. Where no effectual means can be found
+of preventing contact of the steam with a good absorbent
+and conductor of heat, it will be found best to sacrifice
+some of the efficiency due to the change of state of the
+vapor, by superheating it and sending it into the cylinder<span class='pagenum'><a name="Page_476" id="Page_476">[476]</a></span>
+at a temperature considerably exceeding that of saturation.
+With low steam and slowly-moving pistons, it is better to
+pursue the latter course than to attempt to increase the efficiency
+of the engine by greater expansion.</p>
+
+<p>External surfaces should be carefully covered by non-conductors
+and non-radiators, to prevent losses by conduction
+and radiation of heat. It is especially necessary to
+reduce back-pressure and to obtain the most perfect vacuum
+possible without overloading the air-pump, if it is desired
+to obtain the maximum efficiency by expansion, and it then
+becomes also very necessary to reduce losses by &#8220;dead-spaces&#8221;
+and by badly-adjusted valves.</p>
+
+<p>The piston-speed should be as great as can be sustained
+with safety.</p>
+
+<p>Good engines should not require more than W = <span class="enum">200</span>&#8725;<span
+class="denom">&#8730;<span class="bt">P</span></span>
+where W = the weight of steam per hour and per horse-power;
+the best practice gives about W = <span class="enum">180</span>&#8725;<span
+class="denom">&#8730;<span class="bt">P</span></span> in large engines
+with dry steam, high piston-speed, and good design,
+construction, and management.</p>
+
+<p>The expansion-valve gear should be simple. The point
+of cut-off is perhaps best determined by the governor. The
+valve should close rapidly, but without shock, and should
+be balanced, or some other device should be adopted to
+make it easy to move and free from liability to cutting or
+rapid wear.</p>
+
+<p>The governor should act promptly and powerfully, and
+should be free from liability to oscillate, and to thus introduce
+irregularities which are sometimes not less serious than
+those which the instrument is intended to prevent.</p>
+
+<p>Friction should be reduced as much as possible, and careful
+provision should be made to economize lubricants as
+well as fuel.</p>
+
+<p>The Principles of Steam-Boiler Construction are exceedingly
+simple; and although attempts are almost daily made<span class='pagenum'><a name="Page_477" id="Page_477">[477]</a></span>
+to obtain improved results by varying the design and arrangement
+of heating-surface, the best boilers of nearly all
+makers of acknowledged standing are practically equal in
+merit, although of very diverse forms.</p>
+
+<p>In making boilers, the effort of the engineer should
+evidently be:</p>
+
+<p>1. To secure complete combustion of the fuel without
+permitting dilution of the products of combustion by excess
+of air.</p>
+
+<p>2. To secure as high temperature of furnace as possible.</p>
+
+<p>3. To so arrange heating-surfaces that, without checking
+draught, the available heat shall be most completely
+taken up and utilized.</p>
+
+<p>4. To make the form of boiler such that it shall be
+constructed without mechanical difficulty or excessive expense.</p>
+
+<p>5. To give it such form that it shall be durable, under
+the action of the hot gases and of the corroding elements
+of the atmosphere.</p>
+
+<p>6. To make every part accessible for cleaning and repairs.</p>
+
+<p>7. To make every part as nearly as possible uniform in
+strength, and in liability to loss of strength by wear and
+tear, so that the boiler when old shall not be rendered useless
+by local defects.</p>
+
+<p>8. To adopt a reasonably high &#8220;factor of safety&#8221; in
+proportioning parts.</p>
+
+<p>9. To provide efficient safety-valves, steam-gauges, and
+other appurtenances.</p>
+
+<p>10. To secure intelligent and very careful management.</p>
+
+<p>In securing complete combustion, the first of these desiderata,
+an ample supply of air and its thorough intermixture
+with the combustible elements of the fuel are essential;
+for the second&mdash;high temperature of furnace&mdash;it is necessary
+that the air-supply shall not be in excess of that absolutely<span class='pagenum'><a name="Page_478" id="Page_478">[478]</a></span>
+needed to give complete combustion. The efficiency of a
+furnace in making heat available is measured by</p>
+
+<table class="center ind10" cellspacing="0" cellpadding="0" summary="Formula_478">
+
+<tr>
+<td rowspan="2">E&nbsp;=&nbsp;</td>
+<td class="center bb">T&nbsp;-&nbsp;T&#8242;</td>
+<td rowspan="2">&nbsp;;</td>
+</tr>
+
+<tr>
+<td>T&nbsp;-&nbsp;<i>t</i></td>
+</tr>
+
+</table>
+
+<p>in which E represents the ratio of heat utilized to the whole
+calorific value of the fuel, T is the furnace-temperature,
+T&#8242; the temperature of the chimney, and <i>t</i> that of the external
+air. The higher the furnace-temperature and the lower
+that of the chimney, the greater the proportion of heat
+available. It is further evident that, however perfect the
+combustion, no heat can be utilized if either the temperature
+of the chimney approximates to that of the furnace, or
+if the temperature of the furnace is reduced by dilution
+approximately to that of the boiler. Concentration of
+heat in the furnace is secured, in some cases, by special
+expedients, as by heating the entering air, or as in the Siemens
+gas-furnace, heating both the combustible gases and
+the supporter of combustion. Detached fire-brick furnaces
+have an advantage over the &#8220;fire-boxes&#8221; of steam-boilers
+in their higher temperature; surrounding the fire with non-conducting
+and highly heated surfaces is an effective method
+of securing high furnace-temperature.</p>
+
+<p>In arranging heating-surface, the effort should be to impede
+the draught as little as possible, and so to place them
+that the circulation of water within the boiler should be
+free and rapid at every part reached by the hot gases. The
+directions of circulation of water on the one side and of gas
+on the other side of the sheet should, whenever possible, be opposite.
+The cold water should enter where the cooled gases
+leave, and the steam should be taken off farthest from that
+point. The temperature of chimney-gases has thus been
+reduced in practice to less than 300&deg; Fahr., and an efficiency
+equal to 0.75 to 0.80 the theoretical has been attained.</p>
+
+<p>The extent of heating-surface simply, in all of the best
+forms of boiler, determines the efficiency, and in them the
+disposition of that surface seldom affects it to any great<span class='pagenum'><a name="Page_479" id="Page_479">[479]</a></span>
+extent. The area of heating-surface may also be varied
+within very wide limits without very greatly modifying
+efficiency. A ratio of 25 to 1 in flue and 30 to 1 in tubular
+boilers represents the relative area of heating and grate
+surfaces as chosen in the practice of the best-known builders.</p>
+
+<p>The material of the boiler should be tough and ductile
+iron, or, better, a soft steel containing only sufficient carbon
+to insure melting in the crucible or on the hearth of the
+melting-furnace, and so little that no danger may exist of
+hardening and cracking under the action of sudden and
+great changes of temperature.</p>
+
+<p>Where iron is used, it is necessary to select a somewhat
+hard, but homogeneous and tough, quality for the fire-box
+sheets or any part exposed to flames.</p>
+
+<p>The factor of safety is invariably too low in this country,
+and is never too high in Europe. Foreign builders are
+more careful in this matter than our makers in the United
+States. The boiler should be built strong enough to bear a
+pressure at least six times the proposed working-pressure;
+as the boiler grows weak with age, it should be occasionally
+tested to a pressure far above the working-pressure, which
+latter should be reduced gradually to keep within the bounds
+of safety. In the United States, the factor of safety is
+seldom more than four in the new boilers, frequently much
+less, and even this is reduced practically to one and a third
+by the operation of our inspection-laws.</p>
+
+<p>The principles just enunciated are those generally, perhaps
+universally, accepted principles which are stated in all
+text-books of science and of steam-engineering, and are accepted
+by both engineers and men of science.</p>
+
+<p>These principles are correct, and the deductions which
+have been here formulated are rigidly exact, as applied to
+all types of heat-engine in use; and they lead us to the determination,
+in all cases, of the &#8220;modulus&#8221; of efficiency of
+the engine, i. e., to the calculation of the ratio of its actual
+efficiency to that efficiency which it would have, were it<span class='pagenum'><a name="Page_480" id="Page_480">[480]</a></span>
+absolutely free from loss of heat by conduction or radiation,
+or other method of loss of heat or waste of power, by friction
+of parts or by shock.</p>
+
+<p>The best modern marine compound engines sometimes,
+as we have seen, consume as little as two pounds of coal per
+horse-power and per hour; but this is but about one-tenth
+the power derivable from the fuel, were all its heat thoroughly
+utilized. This loss may be divided thus: 70 per
+cent. rejected in exhausted steam; 20 per cent. lost by conduction
+and radiation and by faults of mechanism and design;
+and only the 10 per cent. remaining is utilized. Thirty
+per cent. of the heat generated in the furnace is usually lost
+in the chimney, and of the remainder, which enters the engine,
+20 per cent. at most is all which we can hope to save
+any portion of by improvements effected in our best existing
+type of steam-engine. It has already been shown how
+the engineer can best proceed in attempting this economy.</p>
+
+<p>The direction in which further improvement must take
+place in the standard type of engine is plainly that which
+shall most efficiently check losses by internal condensation
+and re&euml;vaporation by the transfer of heat to and from the
+metal of the steam-cylinder. The condensation of steam
+doing work is evidently not a disadvantage, but, on the contrary,
+a decided advantage.</p>
+
+<p>A new type of engine can, if at all, probably only
+supersede the common form when engineers can employ
+steam of very high pressure, and adopt much greater range
+of expansion than is now usual. Great velocity of piston
+and high speed of rotation are also essential in the attempt to
+make any revolution in steam-engine construction a success.</p>
+
+<p>When a new form of steam-engine is likely to be introduced,
+if at all, can be scarcely even conjectured. It
+seems evident that its success is to be secured, if a revolution
+is ever to occur, by the adoption of high steam-pressures,
+of great piston speeds, by care and skill in design,
+by the use of exceptionally excellent materials of construction,<span class='pagenum'><a name="Page_481" id="Page_481">[481]</a></span>
+by great perfection of workmanship, and by intelligence
+in its management.</p>
+
+<p>Experiment and experience will probably lead gradually
+to the general and safe employment of much higher steam-pressures
+and very greatly increased piston-speeds, and may
+ultimately reveal and remove all those difficulties which
+must invariably be expected to be met here, as in all other
+attempts to effect radical changes, however important they
+may be.</p>
+
+<hr class="l05" />
+<div class="colleft">
+
+<div class="footnote"><p class="left"><a name="Footnote_115_115" id="Footnote_115_115"></a><a
+href="#FNanchor_115_115"><span class="label">[115]</span></a> In some cases, as in the Allen engine, the speed of piston has become
+very high, approaching 800&nbsp;<sup>3</sup>&#8730;<span class="bt">stroke</span>.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_116_116" id="Footnote_116_116"></a><a href="#FNanchor_116_116"><span
+class="label">[116]</span></a> The fact here referred to is easily seen if it is supposed that an engine
+is supplied with steam at a temperature of 400&deg; above absolute zero
+and works it, without waste, down to a temperature of 200&deg;. Suppose one
+inventor to adapt the engine to the use of steam of a range from 500&deg;
+down to 200&deg;, while another works his engine, with equally effective provision
+against losses, between the limits of 400&deg; and 100&deg;, an equal range
+with a lower mean. The first case gives an efficiency of one-half, the
+second three-fifths, and the third three-fourths, the last giving the highest
+effect.</p></div>
+</div>
+
+<div class="footnote"><p class="left"><a name="Footnote_117_117" id="Footnote_117_117"></a><a
+href="#FNanchor_117_117"><span class="label">[117]</span></a> This term, though perhaps not familiar to engineers, expresses the idea
+perfectly.</p></div>
+
+<div class="footnote"><p class="left"><a name="Footnote_118_118" id="Footnote_118_118"></a><a
+href="#FNanchor_118_118"><span class="label">[118]</span></a> The author is not absolutely confident on the latter point. It may be
+found more economical and satisfactory, ultimately, to determine the point
+of cut-off by an automatic apparatus adjusting the expansion-gear <i>by reference
+to the steam-pressure</i>, regulating the speed by attaching the governor
+elsewhere. The author has devised several forms of apparatus of the kind
+referred to.</p></div>
+
+<hr class="l05" />
+
+<div class="figcenter"><img src="images/illo508.png" alt="Ornament" width="250" height="300" /></div>
+
+
+<hr class="c40" />
+<div class="ind20 bbox">
+<h2><i>Scientific Publications.</i></h2>
+<hr class="c40" />
+
+<p><b>THE HUMAN SPECIES.</b> By <span class="smcap">A. De Quatrefages</span>, Professor of Anthropology
+in the Museum of Natural History, Paris. 12mo, cloth, $2.00.</p>
+
+<div class="blockquot"><p>The work treats of the unity, origin, antiquity, and original localization of
+the human species, peopling of the globe, acclimatization, primitive man, formation
+of the human races, fossil human races, present human races, and the physical
+and psychological characters of mankind.</p></div>
+
+
+<p><b>STUDENTS&#8217; TEXT-BOOK OF COLOR; or, MODERN CHROMATICS.</b>
+With Applications to Art and Industry. With 130 Original Illustrations,
+and Frontispiece in Colors. By <span class="smcap">Ogden N. Rood</span>, Professor of
+Physics in Columbia College. 12mo, cloth, $2.00.</p>
+
+<div class="blockquot"><p>&#8220;In this interesting book Professor Rood, who, as a distinguished Professor
+of Physics in Columbia College, United States, must be accepted as a competent
+authority on the branch of science of which he treats, deals briefly and succinctly
+with what may be termed the scientific <i>rationale</i> of his subject. But the chief
+value of his work is to be attributed to the fact that he is himself an accomplished
+artist as well as an authoritative expounder of science.&#8221;&mdash;<i>Edinburgh
+Review, October, 1879, in an article on &#8220;The Philosophy of Color.</i>&#8221;</p></div>
+
+
+<p><b>EDUCATION AS A SCIENCE.</b> By <span class="smcap">Alexander Bain, LL. D.</span> 12mo, cloth,
+$1.75.</p>
+
+<div class="blockquot"><p>&#8220;This work must be pronounced the most remarkable discussion of educational
+problems which has been published in our day. We do not hesitate to
+bespeak for it the widest circulation and the most earnest attention. It should
+be in the hands of every school-teacher and friend of education throughout the
+land.&#8221;&mdash;<i>New York Sun.</i></p></div>
+
+
+<p><b>A HISTORY OF THE GROWTH OF THE STEAM-ENGINE.</b> By
+<span class="smcap">Robert H. Thurston, A. M., C. E.</span>, Professor of Mechanical Engineering
+in the Stevens Institute of Technology, Hoboken, N. J., etc. With 163
+Illustrations, including 15 Portraits. 12mo, cloth, $2.50.</p>
+
+<div class="blockquot"><p>&#8220;Professor Thurston almost exhausts his subject; details of mechanism are
+followed by interesting biographies of the more important inventors. If, as is
+contended, the steam-engine is the most important physical agent in civilizing
+the world, its history is a desideratum, and the readers of the present work will
+agree that it could have a no more amusing and intelligent historian than our
+author.&#8221;&mdash;<i>Boston Gazette.</i></p></div>
+
+
+<p><b>STUDIES IN SPECTRUM ANALYSIS.</b> By <span class="smcap">J. Norman Lockyer, F. R. S.</span>,
+Correspondent of the Institute of France, etc. With 60 Illustrations. 12mo,
+cloth, $2.50.</p>
+
+<div class="blockquot"><p>&#8220;The study of spectrum analysis is one fraught with a peculiar fascination,
+and some of the author&#8217;s experiments are exceedingly picturesque in their results.
+They are so lucidly described, too, that the reader keeps on, from page
+to page, never flagging in interest in the matter before him, nor putting down
+the book until the last page is reached.&#8221;&mdash;<i>New York Evening Express.</i></p></div>
+
+
+
+<p><b>GENERAL PHYSIOLOGY OF MUSCLES AND NERVES.</b> By Dr. <span class="smcap">I.
+Rosenthal</span>, Professor of Physiology at the University of Erlangen. With
+seventy-five Woodcuts. (&#8220;International Scientific Series.&#8221;) 12mo, cloth,
+$1.50.</p>
+
+<div class="blockquot"><p>&#8220;The attempt at a connected account of the general physiology of muscles
+and nerves is, as far as I know, the first of its kind. The general data for this
+branch of science have been gained only within the past thirty years.&#8221;&mdash;<i>Extract
+from Preface.</i></p></div>
+
+
+<p><b>SIGHT</b>: An Exposition of the Principles of Monocular and Binocular Vision
+By <span class="smcap">Joseph Le Conte, LL. D.</span>, author of &#8220;Elements of Geology&#8221;; &#8220;Religion
+and Science&#8221;; and Professor of Geology and Natural History in the
+University of California. With numerous Illustrations. 12mo, cloth, $1.50.</p>
+
+<div class="blockquot"><p>&#8220;It is pleasant to find an American book which can rank with the very best
+of foreign works on this subject. Professor Le Conte has long been known as
+an original investigator in this department; all that he gives us is treated with
+a master-hand.&#8221;&mdash;<i>The Nation.</i></p></div>
+
+
+<p><b>ANIMAL LIFE</b>, as affected by the Natural Conditions of Existence. By
+<span class="smcap">Karl Semper</span>, Professor of the University of W&uuml;rzburg. With 2 Maps
+and 106 Woodcuts, and Index. 12mo, cloth, $2.00.</p>
+
+<div class="blockquot"><p>&#8220;This is in many respects one of the most interesting contributions to
+zo&ouml;logical literature which has appeared for some time.&#8221;&mdash;<i>Nature.</i></p></div>
+
+
+<p><b>THE ATOMIC THEORY.</b> By <span class="smcap">Ad. Wurtz</span>, Membre de l&#8217;Institut; Doyen
+Honoraire de la Facult&eacute; de M&eacute;decine; Professeur &agrave; la Facult&eacute; des Sciences
+de Paris. Translated by <span class="smcap">E. Cleminshaw, M. A., F. C. S., F. I. C.</span>, Assistant
+Master at Sherborne School. 12mo, cloth, $1.50.</p>
+
+<div class="blockquot"><p>&#8220;There was need for a book like this, which discusses the atomic theory both
+in its historic evolution and in its present form. And perhaps no man of this
+age could have been selected so able to perform the task in a masterly way as
+the illustrious French chemist, Adolph Wurtz. It is impossible to convey to the
+reader, in a notice like this, any adequate idea of the scope, lucid instructiveness,
+and scientific interest of Professor Wurtz&#8217;s book. The modern problems of
+chemistry, which are commonly so obscure from imperfect exposition, are here
+made wonderfully clear and attractive.&#8221;&mdash;<i>The Popular Science Monthly.</i></p></div>
+
+
+<p><b>THE CRAYFISH.</b> An Introduction to the Study of Zo&ouml;logy. By Professor
+<span class="smcap">T. H. Huxley, F. R. S.</span> With 82 Illustrations. 12mo, cloth, $1.75.</p>
+
+<div class="blockquot"><p>&#8220;Whoever will follow these pages, crayfish in hand, and will try to verify for
+himself the statements which they contain, will find himself brought face to face,
+with all the great zo&ouml;logical questions which excite so lively an interest at the
+present day.&#8221;</p>
+
+<p>&#8220;The reader of this valuable monograph will lay it down with a feeling of
+wonder at the amount and variety of matter which has been got out of so seemingly
+slight and unpretending a subject.&#8221;&mdash;<i>Saturday Review.</i></p></div>
+
+
+<p><b>SUICIDE</b>: An Essay In Comparative Moral Statistics. By <span class="smcap">Henry Morselli</span>, Professor
+of Psychological Medicine in Royal University, Turin. 12mo, Cloth, $1.75.</p>
+
+<div class="blockquot"><p>&#8220;Suicide&#8221; is a scientific inquiry, on the basis of the statistical method, into the laws
+of suicidal phenomena. Dealing with the subject as a branch of social science, it considers
+the increase of suicide in different countries, and the comparison of nations,
+races, and periods in its manifestation. The influences of age, sex, constitution, climate,
+season, occupation, religion, prevailing ideas, the elements of character, and the
+tendencies of civilization, are comprehensively analyzed in their bearing upon the propensity
+to self-destruction. Professor Morselli is an eminent European authority on
+this subject. It is accompanied by colored maps illustrating pictorially the results of
+statistical inquiries.</p></div>
+
+
+<p><b>VOLCANOES: What they Are and what they Teach.</b> By <span class="smcap">J. W. Judd</span>,
+Professor of Geology in the Royal School of Mines (London). With Ninety-six
+Illustrations. 12mo. Cloth, $2.00.</p>
+
+<div class="blockquot"><p>&#8220;In no field has modern research been more fruitful than in that of which Professor
+Judd gives a popular account in the present volume. The great lines of dynamical,
+geological, and meteorological inquiry converge upon the grand problem of the interior
+constitution of the earth, and the vast influence of subterranean agencies.... His
+book is very far from being a mere dry description of volcanoes and their eruptions; it
+is rather a presentation of the terrestrial facts and laws with which volcanic phenomena
+are associated.&#8221;&mdash;<i>Popular Science Monthly.</i></p>
+
+<p>&#8220;The volume before us is one of the pleasantest science manuals we have read for
+some time.&#8221;&mdash;<i>Athen&aelig;um.</i></p>
+
+<p>&#8220;Mr. Judd&#8217;s summary is so full and so concise that it is almost impossible to give
+a fair idea in a short review.&#8221;&mdash;<i>Pall Mall Gazette.</i></p></div>
+
+
+<p><b>THE SUN.</b> By <span class="smcap">C. A. Young,</span> Ph. D., LL. D., Professor of Astronomy in the College
+of New Jersey. With numerous Illustrations. 12mo. Cloth, $2.00.</p>
+
+<div class="blockquot"><p>&#8220;Professor Young is an authority on &#8216;The Sun,&#8217; and writes from intimate knowledge.
+He has studied that great luminary all his life, invented and improved instruments
+for observing it, gone to all quarters of the world in search of the best places
+and opportunities to watch it, and has contributed important discoveries that have
+extended our knowledge of it.</p>
+
+<p>&#8220;It would take a cyclop&aelig;dia to represent all that has been done toward clearing up
+the solar mysteries. Professor Young has summarized the information, and presented
+it in a form completely available for general readers. There is no rhetoric in his book;
+he trusts the grandeur of his theme to kindle interest and impress the feelings. His
+statements are plain, direct, clear, and condensed, though ample enough for his purpose,
+and the substance of what is generally wanted will be found accurately given in his
+pages.&#8221;&mdash;<i>Popular Science Monthly.</i></p></div>
+
+
+<p><b><a href="http://www.gutenberg.org/ebooks/17815">ILLUSIONS: A Psychological Study.</a></b>
+By <span class="smcap">James Sully</span>, author of &#8220;Sensation
+and Intuition,&#8221; etc. 12mo. Cloth. $1.50.</p>
+
+<div class="blockquot"><p>This volume takes a wide survey of the field of error, embracing in its view not only
+the illusions commonly regarded as of the nature of mental aberrations or hallucinations,
+but also other illusions arising from that capacity for error which belongs essentially
+to rational human nature. The author has endeavored to keep to a strictly scientific
+treatment&mdash;that is to say, the description and classification of acknowledged errors,
+and the exposition of them by a reference to their psychical and physical conditions.</p>
+
+<p>&#8220;This is not a technical work, but one of wide popular interest, in the principles and
+results of which every one is concerned. The illusions of perception of the senses and
+of dreams are first considered, and then the author passes to the illusions of introspection,
+errors of insight, illusions of memory, and illusions of belief. The work is a noteworthy
+contribution to the original progress of thought, and may be relied upon as
+representing the present state of knowledge on the important subject to which it is
+devoted.&#8221;&mdash;<i>Popular Science Monthly.</i></p></div>
+
+
+<p><b>THE BRAIN AND ITS FUNCTIONS.</b> By <span class="smcap">J. Luys</span>, Physician to the
+Hospice de la Salp&ecirc;tri&egrave;re. With Illustrations. 12mo. Cloth, $1.50.</p>
+
+<div class="blockquot"><p>&#8220;No living physiologist is better entitled to speak with authority upon the
+structure and functions of the brain than Dr. Luys. His studies on the anatomy
+of the nervous system are acknowledged to be the fullest and most systematic
+ever undertaken. Dr. Luys supports his conclusions not only by his own anatomical
+researches, but also by many functional observations of various other
+physiologists, including of course Professor Ferrier&#8217;s now classical experiments.&#8221;&mdash;<i>St.
+James&#8217;s Gazette.</i></p>
+
+<p>&#8220;Dr. Luys, at the head of the great French Insane Asylum, is one of the most
+eminent and successful investigators of cerebral science now living; and he has
+given unquestionably the clearest and most interesting brief account yet made of
+the structure and operations of the brain. We have been fascinated by this volume
+more than by any other treatise we have yet seen on the machinery of sensibility
+and thought; and we have been instructed not only by much that is new,
+but by many sagacious practical hints such as it is well for everybody to understand.&#8221;&mdash;<i>The
+Popular Science Monthly.</i></p></div>
+
+
+<p><b>THE CONCEPTS AND THEORIES OF MODERN PHYSICS.</b> By
+<span class="smcap">J. B. Stallo.</span> 12mo. Cloth, $1.75.</p>
+
+<div class="blockquot"><p>&#8220;Judge Stallo&#8217;s work is an inquiry into the validity of those mechanical conceptions
+of the universe which are now held as fundamental in physical science.
+He takes up the leading modern doctrines which are based upon this mechanical
+conception, such as the atomic constitution of matter, the kinetic theory of gases,
+the conservation of energy, the nebular hypothesis, and other views, to find how
+much stands upon solid empirical ground, and how much rests upon metaphysical
+speculation. Since the appearance of Dr. Draper&#8217;s
+&#8216;<a href="http://www.gutenberg.org/ebooks/1185">Religion and Science</a>,&#8217;
+no book has been published in the country calculated to make so deep an impression
+on thoughtful and educated readers as this volume.... The range and
+minuteness of the author&#8217;s learning, the acuteness of his reasoning, and the
+singular precision and clearness of his style, are qualities which very seldom
+have been jointly exhibited in a scientific treatise.&#8221;&mdash;<i>New York Sun.</i></p></div>
+
+
+<p><b><a href="http://www.gutenberg.org/ebooks/2355">THE FORMATION OF VEGETABLE MOULD, THROUGH THE
+ACTION OF WORMS, WITH OBSERVATIONS ON THEIR
+HABITS.</a></b> By <span class="smcap">Charles Darwin</span>, LL. D., F. R. S., author of &#8220;<a
+href="http://www.gutenberg.org/ebooks/1228">On the
+Origin of Species</a>,&#8221; etc., etc. With Illustrations. 12mo, cloth. Price, $1.50.</p>
+
+<div class="blockquot"><p>&#8220;Mr. Darwin&#8217;s little volume on the habits and instincts of earth-worms is no
+less marked than the earlier or more elaborate efforts of his genius by freshness
+of observation, unfailing power of interpreting and correlating facts, and logical
+vigor in generalizing upon them. The main purpose of the work is to point out
+the share which worms have taken in the formation of the layer of vegetable
+mould which covers the whole surface of the land in every moderately humid
+country. All lovers of nature will unite in thanking Mr. Darwin for the new and
+interesting light he has thrown upon a subject so long overlooked, yet so full of
+interest and instruction, as the structure and the labors of the earth-worm.&#8221;&mdash;<i>Saturday
+Review.</i></p>
+
+<p>&#8220;Respecting worms as among the most useful portions of animate nature,
+Dr. Darwin relates, in this remarkable book, their structure and habits, the part
+they have played in the burial of ancient buildings and the denudation of the
+land, in the disintegration of rocks, the preparation of soil for the growth of
+plants, and in the natural history of the world.&#8221;&mdash;<i>Boston Advertiser.</i></p></div>
+
+
+<p><b>ANTS, BEES, AND WASPS.</b> A Record of Observations on the Habits of the
+Social Hymenoptera. By Sir <span class="smcap">John Lubbock</span>, Bart., M. P., F. R. S., etc., author
+of &#8220;Origin of Civilization, and the Primitive Condition of Man,&#8221; etc., etc. With
+Colored Plates. 12mo, cloth, $2.00.</p>
+
+<div class="blockquot"><p>&#8220;This volume contains the record of various experiments made with ants, bees, and
+wasps during the last ten years, with a view to test their mental condition and powers
+of sense. The principal point in which Sir John&#8217;s mode of experiment differs from
+those of Huber, Forel, McCook, and others, is that he has carefully watched and
+marked particular insects, and has had their nests under observation for long periods&mdash;one
+of his ants&#8217; nests having been under constant inspection ever since 1874. His
+observations are made principally upon ants because they show more power and flexibility
+of mind; and the value of his studies is that they belong to the department of
+original research.&#8221;</p>
+
+<p>&#8220;We have no hesitation in saying that the author has presented us with the most
+valuable series of observations on a special subject that has ever been produced, charmingly
+written, full of logical deductions, and, when we consider his multitudinous engagements,
+a remarkable illustration of economy of time. As a contribution to insect
+psychology, it will be long before this book finds a parallel.&#8221;&mdash;<i>London Athen&aelig;um.</i></p></div>
+
+
+<p><b>DISEASES OF MEMORY</b>: An Essay in the Positive Psychology. By <span class="smcap">Th.
+Ribot</span>, author of &#8220;Heredity,&#8221; etc. Translated from the French by William
+Huntington Smith. 12mo, cloth, $1.50.</p>
+
+<div class="blockquot"><p>&#8220;M. Ribot reduces diseases of memory to law, and his treatise is of extraordinary
+interest.&#8221;&mdash;<i>Philadelphia Press.</i></p>
+
+<p>&#8220;Not merely to scientific, but to all thinking men, this volume will prove
+intensely interesting.&#8221;&mdash;<i>New York Observer.</i></p>
+
+<p>&#8220;M. Ribot has bestowed the most painstaking attention upon his theme,
+and numerous examples of the conditions considered greatly increase the value
+and interest of the volume.&#8221;&mdash;<i>Philadelphia North American.</i></p>
+
+<p>&#8220;To the general reader the work is made entertaining by many illustrations
+connected with such names as Linn&aelig;us, Newton, Sir Walter Scott, Horace Vernet,
+Gustave Dor&eacute;, and many others.&#8221;&mdash;<i>Harrisburg Telegraph.</i></p>
+
+<p>&#8220;The whole subject is presented with a Frenchman&#8217;s vivacity of style.&#8221;&mdash;<i>Providence
+Journal.</i></p>
+
+<p>&#8220;It is not too much to say that in no single work have so many curious
+cases been brought together and interpreted in a scientific manner.&#8221;&mdash;<i>Boston
+Evening Traveller.</i></p></div>
+
+
+<p><b><a href="http://www.gutenberg.org/ebooks/17802">MYTH AND SCIENCE.</a></b>
+By <span class="smcap">Tito Vignoli.</span> 12mo, cloth, price, $1.50.</p>
+
+<div class="blockquot"><p>&#8220;His book is ingenious; ... his theory of how science gradually differentiated
+from and conquered myth is extremely well wrought out, and is probably in
+essentials correct.&#8221;&mdash;<i>Saturday Review.</i></p>
+
+<p>&#8220;The book is a strong one, and far more interesting to the general reader than its
+title would indicate. The learning, the acuteness, the strong reasoning power, and the
+scientific spirit of the author, command admiration.&#8221;&mdash;<i>New York Christian Advocate.</i></p>
+
+<p>&#8220;An attempt made, with much ability and no small measure of success, to trace the
+origin and development of the myth. The author has pursued his inquiry with much
+patience and ingenuity, and has produced a very readable and luminous treatise.&#8221;&mdash;<i>Philadelphia
+North American.</i></p>
+
+<p>&#8220;It is a curious if not startling contribution both to psychology and to the early
+history of man&#8217;s development.&#8221;&mdash;<i>New York World.</i></p></div>
+
+
+<p><b>MAN BEFORE METALS.</b> By <span class="smcap">N. Joly</span>, Professor at the Science Faculty
+of Toulouse; Correspondent of the Institute. With 148 Illustrations, 12mo.
+Cloth, $1.75.</p>
+
+<div class="blockquot"><p>&#8220;The discussion of man&#8217;s origin and early history, by Professor De Quatrefages,
+formed one of the most useful volumes in the &#8216;International Scientific Series,&#8217; and
+the same collection is now further enriched by a popular treatise on paleontology, by
+M. N. Joly, Professor in the University of Toulouse. The title of the book, &#8216;Man
+before Metals,&#8217; indicates the limitations of the writer&#8217;s theme. His object is to bring
+together the numerous proofs, collected by modern research, of the great age of the
+human race, and to show us what man was, in respect of customs, industries, and
+moral or religious ideas, before the use of metals was known to him.&#8221;&mdash;<i>New York
+Sun.</i></p>
+
+<p>&#8220;An interesting, not to say fascinating volume.&#8221;&mdash;<i>New York Churchman.</i></p></div>
+
+
+<p><b>ANIMAL INTELLIGENCE.</b> By <span class="smcap">George J. Romanes</span>, F. R. S., Zo&ouml;logical
+Secretary of the Linn&aelig;an Society, etc. 12mo. Cloth, $1.75.</p>
+
+<div class="blockquot"><p>&#8220;My object in the work as a whole is twofold: First, I have thought it desirable
+that there should be something resembling a text-book of the facts of Comparative
+Psychology, to which men of science, and also metaphysicians, may turn whenever
+they have occasion to acquaint themselves with the particular level of intelligence
+to which this or that species of animal attains. My second and much more important
+object is that of considering the facts of animal intelligence in their relation to the
+theory of descent.&#8221;&mdash;<i>From the Preface.</i></p>
+
+<p>&#8220;Unless we are greatly mistaken, Mr. Romanes&#8217;s work will take its place as one
+of the most attractive volumes of the &#8216;International Scientific Series.&#8217; Some persons
+may, indeed, be disposed to say that it is too attractive, that it feeds the popular taste
+for the curious and marvelous without supplying any commensurate discipline in
+exact scientific reflection; but the author has, we think, fully justified himself in his
+modest preface. The result is the appearance of a collection of facts which will be a
+real boon to the student of Comparative Psychology for this is the first attempt to
+present systematically well-assured observations on the mental life of animals.&#8221;&mdash;<i>Saturday
+Review.</i></p>
+
+<p>&#8220;The author believes himself, not without ample cause, to have completely bridged
+the supposed gap between instinct and reason by the authentic proofs here marshaled
+of remarkable intelligence in some of the higher animals. It is the seemingly
+conclusive evidence of reasoning; powers furnished by the adaptation of means to ends
+in cases which can not be explained on the theory of inherited aptitude or habit.&#8221;&mdash;<i>New
+York Sun.</i></p></div>
+
+
+<p><b>THE SCIENCE OF POLITICS.</b> By <span class="smcap">Sheldon Amos</span>, M. A., author of &#8220;The
+Science of Law,&#8221; etc. 12mo. Cloth, $1.75.</p>
+
+<div class="blockquot"><p>&#8220;To the political student and the practical statesman it ought to be of great value.&#8221;&mdash;<i>New
+York Herald.</i></p>
+
+<p>&#8220;The author traces the subject from Plato and Aristotle in Greece, and Cicero in
+Rome, to the modern schools in the English field, not slighting the teachings of the
+American Revolution or the lessons of the French Revolution of 1793. Forms of government,
+political terms, the relation of law, written and unwritten, to the subject, a
+codification from Justinian to Napoleon in France and Field in America, are treated
+as parts of the subject in hand. Necessarily the subjects of executive and legislative
+authority, police, liquor, and land laws are considered, and the question ever growing
+in importance in all countries, the relations of corporations to the state.&#8221;&mdash;<i>New York
+Observer.</i></p></div>
+
+
+<p><b>THE FUNDAMENTAL CONCEPTS OF MODERN PHILOSOPHIC
+THOUGHT, CRITICALLY AND HISTORICALLY CONSIDERED.</b>
+By <span class="smcap">Rudolph Eucken</span>, Ph. D., Professor in Jena. With an
+Introduction by <span class="smcap">Noah Porter</span>, President of Yale College. One vol., 12mo,
+304 pages. Cloth. Price, $1.75.</p>
+
+<div class="blockquot"><p>President Porter declares of this work that &#8220;there are few books within his
+knowledge which are better fitted to aid the student who wishes to acquaint himself
+with the course of modern speculation and scientific thinking, and to form
+an intelligent estimate of most of the current theories.&#8221;</p></div>
+
+
+<p><b>MIND IN THE LOWER ANIMALS IN HEALTH AND DISEASE.</b>
+By <span class="smcap">W. Lauder Lindsay, M. D., F. R. S. E.</span>, etc. 2 vols., 8vo. Cloth, $4.00.</p>
+
+<div class="blockquot"><p>&#8220;The author of this work, which, regarded merely as an accumulation of
+verified and classified facts, is a unique and precious contribution to the data of
+comparative psychology, claims that he entered on his inquiry without any theory
+to defend, support, or illustrate. We are bound to say that, while his general
+conclusions are boldly and continually avowed, his claim of fairness and caution
+is justified by his method of examining particular phenomena; that he seems
+willing at all times to renounce any impression or belief which is shown to be
+scientifically untenable.&#8221;&mdash;<i>New York Sun.</i></p>
+
+<p>&#8220;In this work&mdash;two volumes of over 500 pages&mdash;Dr. Lindsay marshals a proportionately
+large number of facts against those philosophers who maintain that
+the intelligence of man differs in kind and not simply in degree from that of the
+lower animals. It is one purpose of his book to show that the main differences
+between man and the lower animals exist rather in their physical than in their
+mental structure. In this way of thinking, all animals possess not the semblance
+of, but the true substance of mind and will.&#8221;&mdash;<i>New York World.</i></p>
+
+<p>&#8220;So far as we are aware there has been no treatise upon the subject of animal
+intelligence so broad in its foundations, so well considered, or so scientific in its
+methods of inquiry, as that which has been prepared by Dr. W. Lauder Lindsay
+in two large volumes, the first being devoted to a study of animal mind in health,
+and the second to animal mind in disease. We may safely say that his work is,
+in some respects, the most important essay of the kind that has yet been undertaken.
+His observations have been supplemented by a thorough mastery of the
+history and literature of the subject, and hence his conclusions rest upon the
+broadest possible foundation of safe induction. There is a good analytical index
+to the book, as there ought to be to every work of the kind.&#8221;&mdash;<i>New York Evening
+Post.</i></p></div>
+
+
+<p><b>THE ELEMENTARY PRINCIPLES OF SCIENTIFIC AGRICULTURE.</b>
+By <span class="smcap">N. T. Lupton, LL. D.</span>, Professor of Chemistry in Vanderbilt
+University, Nashville, Tenn. 18mo. Cloth. Price, 45 cents.</p>
+
+
+<p><b>A GLOSSARY OF BIOLOGICAL, ANATOMICAL, AND PHYSIOLOGICAL
+TERMS.</b> By <span class="smcap">Thomas Dunman</span>. Small 8vo. Cloth. 161
+pages. Price, $1.00.</p>
+
+<div class="blockquot"><p>&#8220;It has been the author&#8217;s task to furnish here a small and convenient but very
+complete glossary of those terms; and he has done this so well, both in his choice
+of terms for definition and in his clear exposition of their etymological and technical
+meaning, as to leave nothing to be desired in this direction.&#8221;&mdash;<i>New York
+Evening Post.</i></p></div>
+
+<hr class="c25" />
+<p class="center"><i>For sale by all booksellers, or any work sent by mail, post-paid, on receipt of price.</i></p>
+<hr class="c25" />
+<p class="center fsize150">D. APPLETON &amp; CO., Publishers,</p>
+<p class="right"><b>1, 3, &amp; 5 Bond Street, New York.</b></p>
+<p>&nbsp;</p>
+
+<hr class="c40" />
+<h2>SCIENTIFIC LECTURES AND ESSAYS.</h2>
+<hr class="c40" />
+
+<p><b>Popular Lectures on Scientific Subjects.</b> By <span class="smcap">H.
+Helmholtz</span>, Professor of Physics in the University of Berlin. First
+Series. Translated by <span class="smcap">E. Atkinson</span>, Ph. D., F. C. S. With an Introduction
+by Professor <span class="smcap">Tyndall</span>. With 51 Illustrations. 12mo.
+Cloth, $2.00.</p>
+
+<div class="blockquot"><p><i>CONTENTS.</i>&mdash;On the Relation of Natural Science to Science in General.&mdash;On
+Goethe&#8217;s Scientific Researches.&mdash;On the Physiological Causes of Harmony in
+Music&mdash;Ice and Glaciers.&mdash;Interaction of the Natural Forces.&mdash;The Recent Progress
+of the Theory of Vision.&mdash;The Conservation of Force.&mdash;Aim and Progress
+of Physical Science.</p></div>
+
+
+<p><b>Popular Lectures on Scientific Subjects.</b> By <span class="smcap">H.
+Helmholtz</span>. Second Series. 12mo. Cloth, $1.50.</p>
+
+<div class="blockquot"><p><i>CONTENTS.</i>&mdash;Gustav Magnus.&mdash;In Memoriam.&mdash;The Origin and Significance
+of Geometrical Axioms.&mdash;Relation of Optics to Painting.&mdash;Origin of the Planetary
+System.&mdash;On Thought in Medicine.&mdash;Academic Freedom in German Universities.</p>
+
+<p>&#8220;Professor Helmholtz&#8217;s second series of &#8216;Popular Lectures on Scientific Subjects&#8217;
+forms a volume of singular interest and value. He who anticipates a dry
+record of facts or a sequence of immature generalization will find himself happily
+mistaken. In style and method these discourses are models of excellence, and,
+since they come from a man whose learning and authority are beyond dispute,
+they may be accepted as presenting the conclusions of the best thought of the
+times in scientific fields.&#8221;&mdash;<i>Boston Traveler.</i></p></div>
+
+
+<p><b>Science and Culture, and other Essays.</b> By Professor
+<span class="smcap">T. H. Huxley, F. R. S.</span> 12mo. Cloth, $1.50.</p>
+
+<div class="blockquot"><p>&#8220;Of the essays that have been collected by Professor Huxley in this volume,
+the first four deal with some aspect of education. Most of the remainder are expositions
+of the results of biological research, and, at the same time, illustrations
+of the history of scientific ideas. Some of these are among the most interesting
+of Professor Huxley&#8217;s contributions to the literature of science.&#8221;&mdash;<i>London Academy.</i></p>
+
+<p>&#8220;It is refreshing to be brought into converse with one of the most vigorous
+and acute thinkers of our time, who has the power of putting his thoughts into
+language so clear and forcible.&#8221;&mdash;<i>London Spectator.</i></p></div>
+
+
+<p><b>Scientific Culture, and other Essays.</b> By <span class="smcap">Josiah
+Parsons Cooke</span>, Professor of Chemistry and Mineralogy in Harvard
+College. 12mo. Cloth, $1.00.</p>
+
+<div class="blockquot"><p>These essays are an outcome of a somewhat large experience in teaching
+physical science to college students. Cambridge, Massachusetts, early set the
+example of making the student&#8217;s own observations in the laboratory or cabinet
+the basis of all teaching, either in experimental or natural history science; and
+this example has been generally followed. &#8220;But in most centers of education,&#8221;
+writes Professor Cooke, &#8220;the old traditions so far survive that the great end of
+scientific culture is lost in attempting to conform even laboratory instruction to
+the old academic methods of recitations and examinations. To point out this
+error, and to claim for science-teaching its appropriate methods, was one object
+of writing these essays.&#8221;</p></div>
+
+<hr class="c25" />
+<p class="center"><i>For sale by all booksellers; or sent by mail, post-paid, on receipt of price.</i></p>
+<hr class="c25" />
+<p class="center fsize125">New York: D. APPLETON & CO., 1, 3, & 5 Bond Street.</p>
+
+</div>
+<hr class="c40" />
+
+<div class="notebox">
+<p class="center"><a name="TNotes" id="TNotes"></a><b>Transcriber's Notes:</b></p>
+
+<ul>
+  <li>General remarks:
+    <ul>
+      <li>Footnotes have been moved to the end of the chapter.</li>
+      <li>In-line multiple line formulas have been changed to in-line single-line formulas, when necessary with brackets added.</li>
+      <li>The Table of Contents has been corrected to conform to the text rather than to the original Table of Contents.</li>
+      <li>The table on dimensions of farm and road locomotives (page 358) gives the diameter of the boiler shell as <i>30 feet</i>,
+          which seems unlikely.</li>
+      <li>The table on operating costs of trains (page 376) gives <i>Other expenses per square mile.</i> This has been changed to
+          <i>Per mile</i>, the same as the other expenses.</li>
+      <li><i>Feet</i> are sometimes used as unit of area, both <i>knots</i> and <i>knots per hour</i> as unit of speed.</li>
+    </ul>
+  </li>
+  <li>Changes in text:
+    <ul>
+      <li>Minor typographical errors have been corrected.</li>
+      <li>Reference letters in the text have in several cases been changed to conform to the letters used in the illustrations.</li>
+      <li>Except when mentioned here, inconsistencies in spelling have not been corrected. Exceptions:
+          <ul>
+            <li><i>Desagulier</i> to <i>Desaguliers</i>;</li>
+            <li><i>Séguin</i> to <i>Seguin</i>;</li>
+            <li><i>Goldworthy Gurney</i> to <i>Goldsworthy Gurney</i>;</li>
+            <li><i>Ctesibus</i> to <i>Ctesibius</i>;</li>
+            <li><i>i.e.</i> to <i>i. e.</i>;</li>
+            <li><i>Warmetheorie</i> to <i>Wärmetheorie</i>;</li>
+            <li><i>tour a tour</i> to <i>tour à tour</i>;</li>
+            <li><i>the beam passes to the condenser</i> to <i>the steam passes to the condenser</i>;</li>
+            <li><i>éléver</i> to <i>élever</i>.</li>
+          </ul>
+      </li>
+      <li><i>As early as 1743</i> (page 68) moved to new paragraph.</li>
+      <li><i>A = 6.264035</i> changed to <i>a = 6.264035</i> (page 449).</li>
+    </ul>
+  </li>
+  <li>Illustrations:
+    <ul>
+      <li>Illustrations have been moved to the paragraph to which they belong. Page numbers in the List of Illustrations and List of
+          Portraits refer to the original book.</li>
+      <li>Illustrations edited to conform to description and references in text:
+          <ul>
+            <li>Fig. 8: <i>A, F, G</i> changed to <i>A&#8242;, F&#8242;, G&#8242;</i> (right-hand side of illustration);</li>
+            <li>Fig. 19: <i>d</i> (boiler) changed to <i>b</i>;</li>
+            <li>Fig. 21: check-valve <i>e</i> not visible in drawing, <i>l</i> added to illustration;</li>
+            <li>Fig. 26: <i>s</i> added;</li>
+            <li>Fig. 30: lower <i>a</i> and <i>r</i> changed to <i>a&#8242;</i> and <i>r&#8242;</i>;</li>
+            <li>Fig. 41: <i>q</i> and <i>x</i> added;</li>
+            <li>Fig. 42: <i>C</i> flipped over;</li>
+            <li>Fig. 43: right-hand <i>E</i> changed to <i>F</i>;</li>
+            <li>Fig. 48: renamed items <i>t</i> (tank), <i>f</i> (engine cylinder), <i>u</i> (small engine); items <i>p</i> and
+                <i>q</i> not visible in drawing;</li>
+            <li>Fig. 57: <i>f</i> not visible in drawing;</li>
+            <li>Fig. 66: references <i>P, Q, R, S, T, U, C C, Da, D, M</i>, and <i>Fa</i> not visible in drawing, other references
+                indicate other parts than explained in text;</li>
+            <li>Fig. 99: right-hand <i>F</i> changed to <i>E</i>;</li>
+            <li>Fig. 128: <i>X</i> added.</li>
+          </ul>
+      </li>
+      <li>Where details in the illustrations were not clearly visible in this e-book, a link has been provided to see a larger scale
+          illustration; these may (depending on your system) take some time to load and display.</li>
+    </ul>
+  </li>
+</ul>
+
+</div>
+
+
+
+
+
+
+
+
+<pre>
+
+
+
+
+
+End of the Project Gutenberg EBook of A History of the Growth of the
+Steam-Engine, by Robert H. Thurston
+
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+</body>
+</html>
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@@ -0,0 +1,15807 @@
+The Project Gutenberg EBook of A History of the Growth of the Steam-Engine, by
+Robert H. Thurston
+
+This eBook is for the use of anyone anywhere at no cost and with
+almost no restrictions whatsoever.  You may copy it, give it away or
+re-use it under the terms of the Project Gutenberg License included
+with this eBook or online at www.gutenberg.org
+
+
+Title: A History of the Growth of the Steam-Engine
+
+Author: Robert H. Thurston
+
+Release Date: April 19, 2011 [EBook #35916]
+
+Language: English
+
+Character set encoding: ASCII
+
+*** START OF THIS PROJECT GUTENBERG EBOOK STEAM ***
+
+
+
+
+Produced by Chris Curnow, Harry Lame and the Online
+Distributed Proofreading Team at http://www.pgdp.net (This
+file was produced from images generously made available
+by The Internet Archive)
+
+
+
+
+
+
+
+
+
+  +-------------------------------------------------------------------+
+  |                                                                   |
+  |                       TRANSCRIBER'S NOTES:                        |
+  |                                                                   |
+  |                                                                   |
+  |Formatting and coding information:                                 |
+  |  - Text in italics is marked with underscores as in _text_.       |
+  |  - Bold-face text is marked =text=.                               |
+  |  - Superscript x and subscript x are represented as ^{x} and _{x},|
+  |    respectively.                                                  |
+  |  - sqrt(x) represents the square root of x.                       |
+  |  - [oe] and [OE] represent the oe-ligatures.                      |
+  |  - Greek letters are written between square brackets, as in [tau] |
+  |    or [theta].                                                    |
+  |  - Overlined 1 is represented as [=1].                            |
+  |  - [<] represents a 'rotated [Delta]'.                            |
+  |                                                                   |
+  |General remarks:                                                   |
+  |  - Footnotes have been moved to directly below the paragraph they |
+  |    refer to.                                                      |
+  |  - In-line multiple line formulas have been changed to in-line    |
+  |    single-line formulas, with brackets added when needed.         |
+  |  - The Table of Contents has been corrected to conform to the text|
+  |    rather than to the original Table of Contents.                 |
+  |  - The table on operating costs of trains gives 'Other expenses   |
+  |    per square mile.' This has been changed to 'Per mile' the same |
+  |    as the other expenses.                                         |
+  |  - The table on dimensions of farm and road locomotives gives the |
+  |    diameter of the boiler shell as 30 feet, which seems unlikely. |
+  |  - Feet are sometimes used as unit of area, both knots and knots  |
+  |    per hour as unit of speed.                                     |
+  |                                                                   |
+  |Changes in text:                                                   |
+  |  - Reference letters in the text have in several cases been       |
+  |    changed to conform to the letters used in the illustrations.   |
+  |  - Minor typographical errors have been corrected.                |
+  |  - Except when mentioned here, inconsistencies in spelling        |
+  |    and hyphenation have not been corrected. Exceptions:           |
+  |      'Desagulier' to 'Desaguliers'                                |
+  |      'Seguin' to 'Seguin'                                         |
+  |      'Goldworthy Gurney' to 'Goldsworthy Gurney'                  |
+  |      'Ctesibus' to 'Ctesibius'                                    |
+  |      'i.e.' to 'i. e.'                                            |
+  |      'Warmetheorie' to 'Waermetheorie'                             |
+  |      'tour a tour' to 'tour a tour'                               |
+  |      'the beam passes to the' to 'the steam passes to the'        |
+  |      'Desagulier' to 'Desaguliers'                                |
+  |      'elever' to 'elever'.                                        |
+  |  - 'As early as 1743' moved to new paragraph.                     |
+  |  - 'A = 6.264035' changed to 'a = 6.264035.'                      |
+  |                                                                   |
+  +-------------------------------------------------------------------+
+
+
+
+
+                 THE INTERNATIONAL SCIENTIFIC SERIES.
+
+                            VOLUME XXIV.
+
+
+
+
+                                 THE
+                   INTERNATIONAL SCIENTIFIC SERIES.
+
+   EACH BOOK COMPLETE IN ONE VOLUME, 12MO, AND BOUND IN CLOTH.
+
+
+1. FORMS OF WATER: A Familiar Exposition of the Origin and Phenomena
+of Glaciers. By J. TYNDALL, LL. D., F. R. S. With 25 Illustrations.
+$1.50.
+
+2. PHYSICS AND POLITICS; Or, Thoughts on the Application of the
+Principles of "Natural Selection" and "Inheritance" to Political
+Society. By WALTER BAGEHOT. $1.50.
+
+3. FOODS. By EDWARD SMITH, M. D., LL. B., F. R. S. With numerous
+Illustrations. $1.75.
+
+4. MIND AND BODY: The Theories of their Relation. By ALEXANDER BAIN,
+LL. D. With 4 Illustrations. $1.50.
+
+5. THE STUDY OF SOCIOLOGY. By HERBERT SPENCER. $1.50.
+
+6. THE NEW CHEMISTRY. By Professor J. P. COOKE, of Harvard University.
+With 31 Illustrations. $2.00.
+
+7. ON THE CONSERVATION OF ENERGY. By BALFOUR STEWART, M. A., LL. D.,
+F. R. S. With 14 Illustrations. $1.50.
+
+8. ANIMAL LOCOMOTION; or, Walking, Swimming, and Flying. By J. B.
+PETTIGREW, M. D., F. R. S., etc. With 130 Illustrations. $1.75.
+
+9. RESPONSIBILITY IN MENTAL DISEASE. By HENRY MAUDSLEY, M. D. $1.50.
+
+10. THE SCIENCE OF LAW. By Professor SHELDON AMOS. $1.75.
+
+11. ANIMAL MECHANISM: A Treatise on Terrestrial and Aerial Locomotion.
+By Professor E. J. MAREY. With 117 Illustrations. $1.75.
+
+12. THE HISTORY OF THE CONFLICT BETWEEN RELIGION AND SCIENCE. By J. W.
+DRAPER, M. D., LL. D. $1.75.
+
+13. THE DOCTRINE OF DESCENT AND DARWINISM. By Professor OSCAR SCHMIDT
+(Strasburg University). With 26 Illustrations. $1.50.
+
+14. THE CHEMICAL EFFECTS OF LIGHT AND PHOTOGRAPHY. By Dr. HERMANN
+VOGEL (Polytechnic Academy of Berlin). Translation thoroughly revised.
+With 100 Illustrations. $2.00.
+
+15. FUNGI: Their Nature, Influences, Uses, etc. By M. C. COOKE, M. A.,
+LL. D. Edited by the Rev. M. J. Berkeley, M. A., F. L. S. With 109
+Illustrations. $1.50.
+
+16. THE LIFE AND GROWTH OF LANGUAGE. By Professor WILLIAM DWIGHT
+WHITNEY, of Yale College. $1.50.
+
+17. MONEY AND THE MECHANISM OF EXCHANGE. By W. STANLEY JEVONS, M. A.,
+F. R. S. $1.75.
+
+18. THE NATURE OF LIGHT, with a General Account of Physical Optics. By
+Dr. EUGENE LOMMEL. With 188 Illustrations and a Table of Spectra in
+Chromo-lithography. $2.00.
+
+19. ANIMAL PARASITES AND MESSMATES. By Monsieur VAN BENEDEN. With 83
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+          New York: D. APPLETON & CO., 1, 3, & 5 Bond Street.
+
+
+
+
+         [Illustration: THE GRECIAN IDEA OF THE STEAM-ENGINE.]
+
+
+
+
+                  THE INTERNATIONAL SCIENTIFIC SERIES.
+
+                              A HISTORY
+                               OF THE
+                     GROWTH OF THE STEAM-ENGINE.
+
+                                  BY
+
+                  ROBERT H. THURSTON, A. M., C. E.,
+
+    PROFESSOR OF ENGINEERING STEVENS INSTITUTE OF TECHNOLOGY, PAST
+  PRESIDENT AMERICAN SOCIETY MECHANICAL ENGINEERS, MEMBER OF SOCIETY
+      OF CIVIL ENGINEERS, SOCIETE DES INGENIEURS CIVILS, VEREIN
+        DEUTSCHE INGENIEURE, OESTERREICHISCHER INGENIEUR- UND
+          ARCHITEKTEN-VEREIN; ASSOCIATE BRITISH INSTITUTION
+                  OF NAVAL ARCHITECTS, ETC., ETC.
+
+                     _SECOND REVISED EDITION._
+
+                             NEW YORK:
+                     D. APPLETON AND COMPANY,
+                     1, 3, AND 5 BOND STREET.
+                              1886.
+
+
+
+
+                      COPYRIGHT, 1878, 1884,
+                      BY ROBERT H. THURSTON.
+
+
+
+
+PREFACE.
+
+
+This little work embodies the more generally interesting portions of
+lectures first written for delivery at the STEVENS INSTITUTE OF
+TECHNOLOGY, in the winter of 1871-'72, to a mixed audience, composed,
+however, principally of engineers by profession, and of mechanics; it
+comprises, also, some material prepared for other occasions.
+
+These lectures have been rewritten and considerably extended, and have
+been given a form which is more appropriate to this method of
+presentation of the subject. The account of the gradual development of
+the philosophy of the steam-engine has been extended and considerably
+changed, both in arrangement and in method. That part in which the
+direction of improvement during the past history of the steam-engine,
+the course which it is to-day taking, and the direction and limitation
+of that improvement in the future, are traced, has been somewhat
+modified to accord with the character of the revised work.
+
+The author has consulted a large number of authors in the course of
+his work, and is very greatly indebted to several earlier writers. Of
+these, Stuart[1] is entitled to particular mention. His "History" is
+the earliest deserving the name; and his "Anecdotes" are of
+exceedingly great interest and of equally great historical value. The
+artistic and curious little sketches at the end of each chapter are
+from John Stuart, as are, usually, the drawings of the older forms of
+engines.
+
+  [1] "History of the Steam-Engine," London, 1824. "Anecdotes of the
+  Steam-Engine," London, 1829.
+
+Greenwood's excellent translation of Hero, as edited by Bennett
+Woodcroft (London, 1851), can be consulted by those who are curious to
+learn more of that interesting old Greek treatise.
+
+Some valuable matter is from Farey,[2] who gives the most extended
+account extant of Newcomen's and Watt's engines. The reader who
+desires to know more of the life of Worcester, and more of the details
+of his work, will find in the very complete biography of Dircks[3] all
+that he can wish to learn of that great but unfortunate inventor.
+Smiles's admirably written biography of Watt[4] gives an equally
+interesting and complete account of the great mechanic and of his
+partners; and Muirhead[5] furnishes us with a still more detailed
+account of his inventions.
+
+  [2] "Treatise on the Steam-Engine," London, 1827.
+
+  [3] "Life, Times, and Scientific Labors of the Second Marquis of
+  Worcester," London, 1865.
+
+  [4] "Lives of Boulton and Watt," London, 1865.
+
+  [5] "Life of James Watt," D. Appleton & Co., New York, 1859.
+  "Mechanical Inventions of James Watt," London, 1854.
+
+For an account of the life and work of John Elder, the great pioneer
+in the introduction of the now standard double-cylinder, or
+"compound," engine, the student can consult a little biographical
+sketch by Prof. Rankine, published soon after the death of Elder.
+
+The only published sketch of the history of the science of
+thermo-dynamics, which plays so large a part of the philosophy of the
+steam-engine, is that of Prof. Tait--a most valuable monograph.
+
+The section of this work which treats of the causes and the extent of
+losses of heat in the steam-engine, and of the methods available, or
+possibly available, to reduce the amount of this now immense waste of
+heat, is, in some respects, quite new, and is equally novel in the
+method of its presentation. The portraits with which the book is well
+furnished are believed to be authentic, and, it is hoped, will lend
+interest, if not adding to the real value of the work.
+
+Among other works which have been of great assistance to the author,
+and will be found, perhaps, equally valuable to some of the readers of
+this little treatise, are several to which reference has not been made
+in the text. Among them the following are deserving of special
+mention: Zeuner's "Waermetheorie," the treatises of Stewart and of
+Maxwell, and McCulloch's "Mechanical Theory of Heat," a short but
+thoroughly logical and exact mathematical treatise; Cotterill's
+"Steam-Engine considered as a Heat-Engine," a more extended work on
+the same subject, which will be found an excellent companion to, and
+commentary upon, Rankine's "Steam-Engine and Prime Movers," which is
+the standard treatise on the theory of the steam-engine. The works of
+Bourne, of Holley, of Clarke, and of Forney, are standards on the
+practical every-day matters of steam-engine construction and
+management.
+
+The author is almost daily in receipt of inquiries which indicate that
+the above remarks will be of service to very many young engineers, as
+well as to many to whom the steam-engine is of interest from a more
+purely scientific point of view.
+
+
+
+
+                           CONTENTS.
+
+
+                          CHAPTER I.
+
+             THE STEAM-ENGINE AS A SIMPLE MACHINE.
+                                                                  PAGE
+  SECTION I.--THE PERIOD OF SPECULATION--FROM HERO TO WORCESTER,
+  B. C. 200 TO A. D. 1650                                            1
+
+  Introduction--the Importance of the Steam-Engine, 1; Hero and
+  his Treatise on Pneumatics, 4; Hero's Engines, B. C. 200, 8;
+  William of Malmesbury on Steam, A. D. 1150, 10; Hieronymus
+  Cardan on Steam and the Vacuum, 10; Malthesius on the Power of
+  Steam, A. D. 1571, 10; Jacob Besson on the Generation of Steam,
+  A. D. 1578, 11; Ramelli's Work on Machines, A. D. 1588, 11;
+  Leonardo da Vinci on the Steam-Gun, 12; Blasco de Garay's
+  Steamer, A. D. 1543, 12; Battista della Porta's Steam-Engine,
+  A. D. 1601, 13; Florence Rivault on the Force of Steam, A. D.
+  1608, 15; Solomon de Caus's Apparatus, A. D. 1615, 16; Giovanni
+  Branca's Steam-Engine, A. D. 1629, 16; David Ramseye's
+  Inventions, A. D. 1630, 17; Bishop John Wilkins's Schemes, A.
+  D. 1648, 18; Kircher's Apparatus, 19.
+
+  SECTION II.--THE PERIOD OF APPLICATION--WORCESTER, PAPIN, AND
+  SAVERY                                                            19
+
+  Edward Somerset, Marquis of Worcester, A. D. 1663, 19;
+  Worcester's Steam Pumping-Engines, 21; Jean Hautefeuille's
+  Alcohol and Gunpowder Engines, A. D. 1678, 24; Huyghens's
+  Gunpowder-Engine, A. D. 1680, 25; Invention in Great Britain,
+  26; Sir Samuel Morland, A. D. 1683, 27; Thomas Savery and his
+  Engine, A. D. 1698, 31; Desaguliers's Savery Engines, A. D.
+  1718, 41; Denys Papin and his Work, A. D. 1675, 45; Papin's
+  Engines, A. D. 1685-1695, 50; Papin's Steam-Boilers, 51.
+
+
+                             CHAPTER II.
+
+            THE STEAM-ENGINE AS A TRAIN OF MECHANISM.
+
+  THE MODERN TYPE AS DEVELOPED BY NEWCOMEN, BEIGHTON, AND SMEATON   55
+
+  Defects of the Savery Engine, 55; Thomas Newcomen, A. D. 1705,
+  57; the Newcomen Steam Pumping-Engine, 59; Advantages of
+  Newcomen's Engine, 60; Potter's and Beighton's Improvements, A.
+  D. 1713-'18, 61; Smeaton's Newcomen Engines, A. D. 1775, 64;
+  Operation of the Newcomen Engine, 65; Power and Economy of the
+  Engine, 69; Introduction of the Newcomen Engine, 70.
+
+
+                            CHAPTER III.
+
+  THE DEVELOPMENT OF THE MODERN STEAM-ENGINE. JAMES WATT AND HIS
+                           CONTEMPORARIES.
+
+  SECTION I.--JAMES WATT AND HIS INVENTIONS                         79
+
+  James Watt, his Birth and Parentage, 79; his Standing in
+  School, 81; he learns his Trade in London, 81; Return to
+  Scotland and Settlement in Glasgow, 82; the Newcomen Engine
+  Model, 83; Discovery of Latent Heat, 84; Sources of Loss in the
+  Newcomen Engine, 85; Facts experimentally determined by Watt,
+  86; Invention of the Separate Condenser, 87; the Steam-Jacket
+  and other Improvements, 90; Connection with Dr. Roebuck, 91;
+  Watt meets Boulton, 93; Matthew Boulton, 93; Boulton's
+  Establishment at Soho, 95; the Partnership of Boulton and Watt,
+  97; the Kinneil Engine, 97; Watt's Patent of 1769, 98; Work of
+  Boulton and Watt, 101; the Rotative Engine, 103; the Patent of
+  1781, 104; the Expansion of Steam--its Economy, 105; the
+  Double-Acting Engine, 110; the "Compound" Engine, 110; the
+  Steam-Hammer, 111; Parallel Motions, the Counter, 112; the
+  Throttle-Valve and Governor, 114; Steam, Vacuum, and Water
+  Gauges, 116; Boulton & Watt's Mill-Engine, 118; the Albion Mill
+  and its Engine, 119; the Steam-Engine Indicator, 123; Watt in
+  Social Life, 125; Discovery of the Composition of Water, 126;
+  Death of James Watt, 128; Memorials and Souvenirs, 128.
+
+  SECTION II.--THE CONTEMPORARIES OF JAMES WATT                    132
+
+  William Murdoch and his Work, 132; Invention of Gas-Lighting,
+  134; Jonathan Hornblower and the Compound Engine, 135; Causes
+  of the Failure of Hornblower, 137; William Bull and Richard
+  Trevithick, 138; Edward Cartwright and his Engine, 140.
+
+
+                           CHAPTER IV.
+
+                     THE MODERN STEAM-ENGINE.
+
+  THE SECOND PERIOD OF APPLICATION--1800-1850--STEAM-LOCOMOTION
+  ON RAILROADS                                                     144
+
+  Introduction, 144; the Non-Condensing Engine and the
+  Locomotive, 147; Newton's Locomotive, 1680, 149; Nathan Read's
+  Steam-Carriage, 150; Cugnot's Steam-Carriage, 1769, 151; the
+  Model Steam-Carriage of Watt and Murdoch, 1784, 153; Oliver
+  Evans and his Plans, 1786, 153; Evans's Oruktor Amphibolis,
+  1804, 157; Richard Trevithick's Steam-Carriage, 1802, 159;
+  Steam-Carriages of Griffiths and others, 160; Steam-Carriages
+  of Goldsworthy Gurney, 1827, 161; Steam-Carriages of Walter
+  Hancock, 1831, 165; Reports to the House of Commons, 1831, 170;
+  the Introduction of the Railroad, 172; Richard Trevithick's
+  Locomotives, 1804, 174; John Stevens and the Railroad, 1812,
+  178; William Hedley's Locomotives, 1812, 181; George
+  Stephenson, 183; Stephenson's Killingworth Engine, 1813, 186;
+  Stephenson's Second Locomotive, 1815, 187; Stephenson's
+  Safety-Lamp, 1815, 187; Robert Stephenson & Co., 1824, 190; the
+  Stockton & Darlington Engine, 1825, 191; the Liverpool &
+  Manchester Railroad, 1826, 193; Trial of Competing Engines at
+  Rainhill, 1829, 195; the Rocket and the Novelty, 198;
+  Atmospheric Railways, 201; Character of George Stephenson,
+  204; the Locomotive of 1833, 204; Introduction of Railroads in
+  Europe, 206; Introduction of Railroads in the United States,
+  207; John Stevens's Experimental Railroad, 1825, 207; Horatio
+  Allen and the "Stourbridge Lion," 1829, 208; Peter Cooper's
+  Engine, 1829, 209; E. L. Miller and the S. C. Railroad, 1830,
+  210; the "American" Type of Engine of John B. Jervis, 1832,
+  212; Robert L. Stevens and the T-rail, 1830, 214; Matthias W.
+  Baldwin and his Engine, 1831, 215; Robert Stephenson on the
+  Growth of the Locomotive, 220.
+
+
+                           CHAPTER V.
+
+                    THE MODERN STEAM-ENGINE.
+
+  THE SECOND PERIOD OF APPLICATION--1800-1850 (CONTINUED)--THE
+  STEAM-ENGINE APPLIED TO SHIP-PROPULSION                          221
+
+  Introduction, 221; Ancient Prophecies, 223; the Earliest
+  Paddle-Wheel, 223; Blasco de Garay's Steam-Vessel, 1543, 224;
+  Experiments of Dionysius Papin, 1707, 214; Jonathan Hulls's
+  Steamer, 1736, 225; Bernouilli and Gauthier, 228; William
+  Henry, 1782, 230; the Comte d'Auxiron, 1772, 232; the Marquis
+  de Jouffroy, 1776, 233; James Rumsey, 1774, 234; John Fitch,
+  1785, 285; Fitch's Experiments on the Delaware, 1787, 237;
+  Fitch's Experiments at New York, 1796, 240; the Prophecy of
+  John Fitch, 241; Patrick Miller, 1786-'87, 241; Samuel Morey,
+  1793, 243; Nathan Read, 1788, 244; Dundas and Symmington, 1801,
+  246; Henry Bell and the Comet, 1811, 248; Nicholas Roosevelt,
+  1798, 250; Robert Fulton, 1802, 251; Fulton's Torpedo-Vessels,
+  1801, 252; Fulton's First Steamboat, 1803, 253; the Clermont,
+  1807, 257; Voyage of the Clermont to Albany, 259; Fulton's
+  Later Steamboats, 260; Fulton's War-Steamer Fulton the First,
+  1815, 261; Oliver Evans, 1804, 263; John Stevens's
+  Screw-Steamer, 1804, 264; Stevens's Steam-Boilers, 1804, 264;
+  Stevens's Iron-Clad, 1812, 268; Robert L. Stevens's
+  Improvements, 270; the "Stevens Cut-off," 1841, 276; the
+  Stevens Iron-Clad, 1837, 277; Robert L. Thurston and John
+  Babcock, 1821, 280; James P. Allaire and the Messrs. Copeland,
+  281; Erastus W. Smith's Compound Engine, 283; Steam-Navigation
+  on Western Rivers, 1811, 283; Ocean Steam-Navigation, 1808,
+  285; the Savannah, 1819, 286; the Sirius and the Great Western,
+  1838, 289; the Cunard Line, 1840, 290; the Collins Line, 1851,
+  291; the Side-Lever Engine, 292; Introduction of
+  Screw-Steamers, 293; John Ericsson's Screw-Vessels, 1836, 294;
+  Francis Pettit Smith, 1837, 296; the Princeton, 1841, 297;
+  Advantages of the Screw, 299; the Screw on the Ocean, 300;
+  Obstacles to Improvement, 301; Changes in Engine-Construction,
+  302; Conclusion, 303.
+
+
+                           CHAPTER VI.
+
+                    THE STEAM-ENGINE OF TO-DAY.
+
+  THE PERIOD OF REFINEMENT--1850 TO DATE                           303
+
+  Condition of the Steam-Engine at this Time, 303; the Later
+  Development of the Engine, 304; Stationary Steam-Engines, 307;
+  the Steam-Engine for Small Powers, 307; the Horizontal Engine
+  with Meyer Valve-Gear, 311; the Allen Engine, 314; its
+  Performance, 316; the Detachable Valve-Gear, 316; the Sickels
+  Cut-off, 317; Expansion adjusted by the Governor, 318; the
+  Corliss Engine, 319; the Greene Engine, 321; Perkins's
+  Experiments, 323; Dr. Alban's Work, 325; the Perkins Compound
+  Engine, 327; the Modern Pumping-Engine, 328; the Cornish
+  Engine, 328; the Steam-Pump, 331; the Worthington
+  Pumping-Engine, 333; the Compound Beam and Crank Engine, 335;
+  the Leavitt Pumping-Engine, 336; the Stationary Steam-Boiler,
+  338; "Sectional" Steam-Boilers, 343; "Performance" of Boilers,
+  344.
+
+  SECTION II.--PORTABLE AND LOCOMOTIVE ENGINES.                    347
+
+  The Semi-Portable Engine, 348; Performance of Portable Engines,
+  350; their Efficiency, 352; the Hoadley Engine, 354; the Mills
+  Farm and Road Engine, 356; Fisher's Steam-Carriage, 356;
+  Performance of Road-Engines, 357; Trial of Road-Locomotives by
+  the Author, 358; Conclusions, 358; the Steam Fire-Engine, 360;
+  the Rotary Steam-Engine and Pump, 365; the Modern Locomotive,
+  368; Dimensions and Performance, 373; Compound Engines for
+  Locomotives, 376; Extent of Modern Railroads, 378;
+
+  SECTION III.--MARINE ENGINES.                                    379
+
+  The Modern Marine Engine, 379; the American Beam Engine, 379;
+  the Oscillating Engine and Feathering Wheel, 381; the two
+  "Rhode Islands," 382; River-Boat Engines on the Mississippi,
+  384; Steam Launches and Yachts, 386; Marine Screw-Engines, 389;
+  the Marine Compound Engine, 390; its Introduction by John Elder
+  and others, 393; Comparison with the Single-Cylinder Engine,
+  395; its Advantages, 396; the Surface Condenser, 397; Weight of
+  Machinery, 398; Marine Engine Performance, 398; Relative
+  Economy of Simple and Compound Engines, 399; the
+  Screw-Propeller, 399; Chain-Propulsion, or Wire-Rope Towage,
+  402; Marine Steam-Boilers, 403; the Modern Steamship, 405;
+  Examples of Merchant Steamers, 406; Naval
+  Steamers--Classification, 409; Examples of Iron-Clad Steamers,
+  412; Power of the Marine Engine, 415; Conclusion, 417.
+
+
+                          CHAPTER VII.
+
+              THE PHILOSOPHY OF THE STEAM-ENGINE.
+
+  THE HISTORY OF ITS GROWTH; ENERGETICS AND THERMO-DYNAMICS        419
+
+  General Outline, 419; Origin of its Power, 419; Scientific
+  Principles involved in its Operation, 420; the Beginnings of
+  Modern Science, 421; the Alexandrian Museum, 422; the
+  Aristotelian Philosophy, 424; the Middle Ages, 426; Galileo's
+  Work, 428; Da Vinci and Stevinus, 429; Kepler, Hooke, and
+  Huyghens, 429; Newton and the New Mechanical Philosophy, 430;
+  the Inception of the Science of Energetics, 483; the
+  Persistence of Energy, 433; Rumford's Experiments, 434;
+  Fourier, Carnot, Seguin, 437; Mayer and the Mechanical
+  Equivalent of Heat, 438; Joule's Determination of its Value,
+  438; Prof. Rankine's Investigations, 442; Clausius-Thompson's
+  Principles, 444; Experimental Work of Boyle, Black, and Watt,
+  446; Robison's, Dalton's, Ure's, and Biot's Study of Pressures
+  and Temperatures of Steam, 447; Arago's and Dulong's
+  Researches, 447; Franklin Institute Investigation, 447;
+  Cagniard de la Tour--Faraday, 447; Dr. Andrews and the Critical
+  Point, 448; Donny's and Dufour's Researches, 448; Regnault's
+  Determination of Temperatures and Pressures of Steam, 449;
+  Hirn's Experiments, 450; Resume of the Philosophy of the
+  Steam-Engine, 451; Energy--Definitions and Principles, 451; its
+  Measure, 452; the Laws of Energetics, 453; Thermo-dynamics,
+  453; its Beginnings, 454; its Laws, 454; Rankine's General
+  Equation, 455; Rankine's Treatise on the Theory of
+  Heat-Engines, 456; Merits of the Great Philosopher, 456.
+
+
+                         CHAPTER VIII.
+
+              THE PHILOSOPHY OF THE STEAM-ENGINE.
+
+  ITS APPLICATION; ITS TEACHINGS RESPECTING THE CONSTRUCTION OF
+  THE ENGINE AND ITS IMPROVEMENT                                   457
+
+  Origin of all Energy, 457; the Progress of Energy through
+  Boiler and Engine, 458; Conditions of Heat-Development in the
+  Boiler, 458; the Steam in the Engine, 458; the Expansion of
+  Steam, 459; Conditions of Heat-Utilization, 460; Loss of Power
+  in the Engine, 462; Conditions affecting the Design of the
+  Steam-Engine, 466; the Problem stated, 466; Economy as affected
+  by Pressure and Temperature, 467; Changes which have already
+  occurred, 468; Direction of Changes now in Progress, 470;
+  Summary of Facts, 471; Characteristics of a Good Steam-Engine,
+  473; Principles of Steam-Boiler Construction, 476.
+
+
+
+
+                      LIST OF ILLUSTRATIONS.
+
+
+  FRONTISPIECE: The Grecian Idea of the Steam-Engine.
+
+  FIG.                                                            PAGE
+    1. Opening Temple-Doors by Steam, B. C. 200                      6
+    2. Steam Fountain, B. C. 200                                     7
+    3. Hero's Engine, B. C. 200                                      8
+    4. Porta's Apparatus, A. D. 1601                                14
+    5. De Caus's Apparatus, A. D. 1605                              15
+    6. Branca's Steam-Engine, A. D. 1629                            17
+    7. Worcester's Steam-Fountain, A. D. 1650                       21
+    8. Worcester's Engine, A. D. 1665                               22
+    9. Wall of Raglan Castle                                        22
+   10. Huyghens's Engine, 1680                                      26
+   11. Savery's Model, 1698                                         34
+   12. Savery's Engine, 1698                                        35
+   13. Savery's Engine, A. D. 1702                                  37
+   14. Papin's Two-Way Cock                                         42
+   15. Engine Built by Desaguliers in 1718                          43
+   16. Papin's Digester, 1680                                       48
+   17. Papin's Engine                                               50
+   18. Papin's Engine and Water-Wheel, A. D. 1707                   53
+   19. Newcomen's Engine, A. D. 1705                                59
+   20. Beighton's Valve-Gear, A. D. 1718                            63
+   21. Smeaton's Newcomen Engine                                    65
+   22. Boiler of Newcomen Engine, 1763                              67
+   23. Smeaton's Portable-Engine Boiler, 1765                       73
+   24. The Newcomen Model                                           84
+   25. Watt's Experiment                                            89
+   26. Watt's Engine, 1774                                          98
+   27. Watt's Engine, 1781                                         104
+   28. Expansion of Steam                                          108
+   29. The Governor                                                115
+   30. Mercury Steam-Gauge and Glass Water-Gauge                   117
+   31. Boulton & Watt's Double-Acting Engine, 1784                 119
+   32. Valve-Gear of the Albion Mills Engine                       121
+   33. Watt's Half-Trunk Engine, 1784                              122
+   34. The Watt Hammer, 1784                                       123
+   35. James Watt's Workshop                                       129
+   36. Murdoch's Oscillating Engine, 1785                          134
+   37. Hornblower's Compound Engine, 1781                          136
+   38. Bull's Pumping-Engine, 1798                                 139
+   39. Cartwright's Engine, 1798                                   141
+   40. The First Railroad-Car, 1825                                144
+   41. Leupold's Engine, 1720                                      148
+   42. Newton's Steam-Carriage, 1680                               149
+   43. Read's Steam-Carriage, 1790                                 150
+   44. Cugnot's Steam-Carriage, 1770                               151
+   45. Murdoch's Model, 1784                                       153
+   46. Evans's Non-Condensing Engine, 1800                         156
+   47. Evans's "Oruktor Amphibolis," 1804                          157
+   48. Gurney's Steam-Carriage                                     163
+   49. Hancock's "Autopsy", 1833                                   168
+   50. Trevithick's Locomotive, 1804                               175
+   51. Stephenson's Locomotive of 1815. Section                    187
+   52. Stephenson's No. 1 Engine, 1825                             191
+   53. Opening of the Stockton and Darlington Railroad, 1815       192
+   54. The "Novelty," 1829                                         197
+   55. The "Rocket," 1829                                          198
+   56. The Atmospheric Railroad                                    202
+   57. Stephenson's Locomotive, 1833                               203
+   58. The Stephenson Valve-Gear, 1833                             206
+   59. The "Atlantic," 1832                                        210
+   60. The "Best Friend," 1830                                     211
+   61. The "West Point," 1831                                      212
+   62. The "South Carolina," 1831                                  213
+   63. The "Stevens" Rail and Enlarged Section                     215
+   64. "Old Ironsides," 1832                                       216
+   65. The "E. L. Miller," 1834                                    217
+   66. Hulls's Steamboat, 1736                                     226
+   67. Fitch's Model, 1785                                         236
+   68. Fitch & Voight's Boiler, 1787                               238
+   69. Fitch's First Boat, 1787                                    238
+   70. John Fitch, 1788                                            239
+   71. John Fitch, 1796                                            240
+   72. Miller, Taylor & Symmington, 1788                           242
+   73. Read's Boiler in Section, 1788                              245
+   74. Read's Multi-Tubular Boiler, 1788                           245
+   75. The "Charlotte Dundas," 1801                                247
+   76. The "Comet," 1812                                           248
+   77. Fulton's Experiments                                        253
+   78. Fulton's Table of Resistances                               254
+   79. Barlow's Water-Tube Boiler, 1793                            256
+   80. The "Clermont," 1807                                        258
+   81. Engine of the "Clermont," 1808                              258
+   82. Launch of the "Fulton the First," 1804                      262
+   83. Section of Steam-Boiler, 1804                               264
+   84. Engine, Boiler, and Screw-Propellers used by Stevens, 1804  265
+   85. Stevens's Screw Steamer, 1804                               265
+   86. John Stevens's Twin-Screw Steamer, 1805                     269
+   87. The Feathering Paddle-Wheel                                 272
+   88. The "North America" and "Albany," 1827-'30                  274
+   89. Stevens's Return Tubular Boiler, 1832                       275
+   90. Stevens's Valve-Motion                                      276
+   91. The "Atlantic," 1851                                        290
+   92. The Side-Lever Engine, 1849                                 291
+   93. Vertical Stationary Steam-Engine                            308
+   94. Vertical Stationary Steam-Engine. Section                   309
+   95. Horizontal Stationary Steam-Engine                          312
+   96. Horizontal Stationary Steam-Engine                          313
+   97. Corliss Engine                                              319
+   98. Corliss Engine Valve-Motion                                 320
+   99. Greene Engine                                               321
+  100. Thurston's Greene-Engine Valve-Gear                         322
+  101. Cornish Pumping-Engine, 1880                                329
+  102. Steam-Pump                                                  331
+  103. The Worthington Pumping-Engine, 1876. Section               333
+  104. The Worthington Pumping-Engine                              334
+  105. Double-Cylinder Pumping-Engine, 1878                        335
+  106. The Lawrence Water-Works Engine                             336
+  107. The Leavitt Pumping-Engine                                  337
+  108. Babcock & Wilcox's Vertical Boiler                          341
+  109. Stationary "Locomotive" Boiler                              342
+  110. Galloway Tube                                               343
+  111. Harrison's Sectional Boiler                                 345
+  112. Babcock and Wilcox's Sectional Boiler                       346
+  113. Root Sectional Boiler                                       347
+  114. Semi-Portable Engine, 1878                                  348
+  115. Semi-Portable Engine, 1878                                  349
+  116. The Portable Steam-Engine, 1878                             354
+  117. The Thrashers' Road-Engine, 1878                            355
+  118. Fisher's Steam-Carriage                                     356
+  119. Road and Farm Locomotive                                    357
+  120. The Latta Steam Fire-Engine                                 361
+  121. The Amoskeag Engine. Section                                363
+  122. The Silsby Rotary Steam Fire-Engine                         364
+  123. Rotary Steam-Engine                                         365
+  124. Rotary Pump                                                 366
+  125. Tank Engine, New York Elevated Railroad                     369
+  126. Forney's Tank-Locomotive                                    370
+  127. British Express Engine                                      371
+  128. The Baldwin Locomotive. Section                             372
+  129. The American Type of Express Engine, 1878                   374
+  130. Beam Engine                                                 380
+  131. Oscillating Steam-Engine and Feathering Paddle-Wheel        381
+  132. The Two "Rhode Islands," 1836-1876                          383
+  133. A Mississippi Steamboat                                     384
+  134. Steam-Launch, New York Steam-Power Company                  386
+  135. Launch-Engine                                               387
+  136. Horizontal, Direct-acting Naval Screw Engine                389
+  137. Compound Marine Engine. Side Elevation                      390
+  138. Compound Marine Engine. Front Elevation and Section         391
+  139. Screw-Propeller                                             400
+  140. Tug-Boat Screw                                              401
+  141. Hirsch Screw                                                401
+  142. Marine Fire-Tubular Boiler. Section                         403
+  143. Marine High-Pressure Boiler. Section                        404
+  144. The Modern Steamship                                        407
+  145. Modern Iron-Clads                                           410
+  146. The "Great Eastern"                                         415
+  147. The "Great Eastern" at Sea                                  416
+
+
+
+
+                         PORTRAITS.
+
+
+  NO.                                                             PAGE
+   1. Edward Somerset, the Second Marquis of Worcester              20
+   2. Thomas Savery                                                 31
+   3. Denys Papin                                                   46
+   4. James Watt                                                    80
+   5. Matthew Boulton                                               94
+   6. Oliver Evans                                                 154
+   7. Richard Trevithick                                           174
+   8. Colonel John Stevens                                         178
+   9. George Stephenson                                            183
+  10. Robert Fulton                                                251
+  11. Robert L. Stevens                                            270
+  12. John Elder                                                   393
+  13. Benjamin Thompson, Count Rumford                             434
+  14. James Prescott Joule                                         439
+  15. Prof. W. J. M. Rankine                                       443
+
+
+
+
+  ["A Machine, receiving at distant times and from many hands new
+  combinations and improvements, and becoming at last of signal
+  benefit to mankind, may be compared to a rivulet swelled in its
+  course by tributary streams, until it rolls along a majestic river,
+  enriching, in its progress, provinces and kingdoms.
+
+  "In retracing the current, too, from where it mingles with the
+  ocean, the pretensions of even ample subsidiary streams are merged
+  in our admiration of the master-flood, glorying, as it were, in its
+  expansion. But as we continue to ascend, those waters which, nearer
+  the sea, would have been disregarded as unimportant, begin to rival
+  in magnitude and share our attention with the parent stream; until,
+  at length, on our approaching the fountains of the river, it appears
+  trickling from the rock, or oozing from among the flowers of the
+  valley.
+
+  "So, also, in developing the rise of a machine, a coarse instrument
+  or a toy may be recognized as the germ of that production of
+  mechanical genius, whose power and usefulness have stimulated our
+  curiosity to mark its changes and to trace its origin. The same
+  feelings of reverential gratitude which attached holiness to the
+  spot whence mighty rivers sprang, also clothed with divinity, and
+  raised altars in honor of, inventors of the saw, the plough, the
+  potter's wheel, and the loom."--STUART.]
+
+
+
+
+THE GROWTH OF THE STEAM-ENGINE.
+
+
+
+
+CHAPTER I.
+
+_THE STEAM-ENGINE AS A SIMPLE MACHINE._
+
+
+SECTION I.--THE PERIOD OF SPECULATION--FROM HERO TO WORCESTER, B. C.
+200 TO A. D. 1650.
+
+One of the greatest of modern philosophers--the founder of that system
+of scientific philosophy which traces the processes of evolution in
+every department, whether physical or intellectual--has devoted a
+chapter of his "First Principles" of the new system to the
+consideration of the multiplication of the effects of the various
+forces, social and other, which are continually modifying this
+wonderful and mysterious universe of which we form a part. Herbert
+Spencer, himself an engineer, there traces the wide-spreading,
+never-ceasing influences of new inventions, of the introduction of new
+forms of mechanism, and of the growth of industrial organization, with
+a clearness and a conciseness which are so eminently characteristic of
+his style. His illustration of this idea by reference to the manifold
+effects of the introduction of steam-power and its latest embodiment,
+the locomotive-engine, is one of the strongest passages in his work.
+The power of the steam-engine, and its inconceivable importance as an
+agent of civilization, has always been a favorite theme with
+philosophers and historians as well as poets. As Religion has always
+been, and still is, the great _moral_ agent in civilizing the world,
+and as Science is the great _intellectual_ promoter of civilization,
+so the Steam-Engine is, in modern times, the most important _physical_
+agent in that great work.
+
+It would be superfluous to attempt to enumerate the benefits which it
+has conferred upon the human race, for such an enumeration would
+include an addition to every comfort and the creation of almost every
+luxury that we now enjoy. The wonderful progress of the present
+century is, in a very great degree, due to the invention and
+improvement of the steam-engine, and to the ingenious application of
+its power to kinds of work that formerly taxed the physical energies
+of the human race. We cannot examine the methods and processes of any
+branch of industry without discovering, somewhere, the assistance and
+support of this wonderful machine. Relieving mankind from manual toil,
+it has left to the intellect the privilege of directing the power,
+formerly absorbed in physical labor, into other and more profitable
+channels. The intelligence which has thus conquered the powers of
+Nature, now finds itself free to do head-work; the force formerly
+utilized in the carrying of water and the hewing of wood, is now
+expended in the God-like work of THOUGHT. What, then, can be more
+interesting than to trace the history of the growth of this wonderful
+machine?--the greatest among the many great creations of one of God's
+most beneficent gifts to man--the power of invention.
+
+While following the records and traditions which relate to the
+steam-engine, I propose to call attention to the fact that its history
+illustrates the very important truth: _Great inventions are never, and
+great discoveries are seldom, the work of any one mind_. Every great
+invention is really either an aggregation of minor inventions, or the
+final step of a progression. It is not a creation, but _a growth_--as
+truly so as is that of the trees in the forest. Hence, the same
+invention is frequently brought out in several countries, and by
+several individuals, simultaneously. Frequently an important invention
+is made before the world is ready to receive it, and the unhappy
+inventor is taught, by his failure, that it is as unfortunate to be in
+advance of his age as to be behind it. Inventions only become
+successful when they are not only needed, but when mankind is so far
+advanced in intelligence as to appreciate and to express the necessity
+for them, and to at once make use of them.
+
+More than half a century ago, an able New England writer, in a
+communication to an English engineering periodical, described the new
+machinery which was built at Newport, R. I., by John Babcock and
+Robert L. Thurston, for one of the first steamboats that ever ran
+between that city and New York. He prefaced his description with a
+frequently-quoted remark to the effect that, as Minerva sprang, mature
+in mind, in full stature of body, and completely armed, from the head
+of Jupiter, so the steam-engine came forth, perfect at its birth, from
+the brain of James Watt. But we shall see, as we examine the records
+of its history, that, although James Watt was _an_ inventor, and
+probably the greatest of the inventors of the steam-engine, he was
+still but one of the many men who have aided in perfecting it, and who
+have now made us so familiar with it, and its tremendous power and its
+facile adaptations, that we have almost ceased to admire it, or to
+wonder at the workings of the still more admirable intelligence that
+has so far perfected it.
+
+Twenty-one centuries ago, the political power of Greece was broken,
+although Grecian civilization had risen to its zenith. Rome, ruder
+than her polished neighbor, was growing continually stronger, and was
+rapidly gaining territory by absorbing weaker states. Egypt, older in
+civilization than either Greece or Rome, fell but two centuries later
+before the assault of the younger states, and became a Roman province.
+Her principal city was at this time Alexandria, founded by the great
+soldier whose name it bears, when in the full tide of his prosperity.
+It had now become a great and prosperous city, the centre of the
+commerce of the world, the home of students and of learned men, and
+its population was the wealthiest and most civilized of the then known
+world.
+
+It is among the relics of that ancient Egyptian civilization that we
+find the first records in the early history of the steam-engine. In
+Alexandria, the home of Euclid, the great geometrician, and possibly
+contemporary with that talented engineer and mathematician,
+Archimedes, a learned writer, called Hero, produced a manuscript which
+he entitled "Spiritalia seu Pneumatica."
+
+It is quite uncertain whether Hero was the inventor of any number of
+the contrivances described in his work. It is most probable that the
+apparatus described are principally devices which had either been long
+known, or which were invented by Ctesibius, an inventor who was famous
+for the number and ingenuity of the hydraulic and pneumatic machines
+that he devised. Hero states, in his Introduction, his intention to
+describe existing machines and earlier inventions, and to add his own.
+Nothing in the text, however, indicates to whom the several machines
+are to be ascribed.[6]
+
+  [6] The British Museum contains four manuscript copies of Hero's
+  "Pneumatics," which were written in the fifteenth and sixteenth
+  centuries. These manuscripts have been examined with great care, and
+  a translation from them prepared by Prof. J. G. Greenwood, and
+  published at the desire of Mr. Bennett Woodcroft, the author of a
+  valuable little treatise on "Steam Navigation." This is, so far as
+  the author is aware, the only existing English translation of any
+  portion of Hero's works.
+
+The first part of Hero's work is devoted to applications of the
+syphon. The 11th proposition is the first application of heat to
+produce motion of fluids.
+
+An altar and its pedestal are hollow and air-tight. A liquid is poured
+into the pedestal, and a pipe inserted, of which the lower end passes
+beneath the surface of the liquid, and the upper extremity leads
+through a figure standing at the altar, and terminates in a vessel
+inverted above this altar. When a fire is made on the altar, the heat
+produced expands the confined air, and the liquid is driven up the
+tube, issuing from the vessel in the hand of the figure standing by
+the altar, which thus seems to be offering a libation. This toy
+embodies the essential principle of all modern heat-engines--the
+change of energy from the form known as heat-energy into mechanical
+energy, or work. It is not at all improbable that this prototype of
+the modern wonder-working machine may have been known centuries before
+the time of Hero.
+
+Many forms of hydraulic apparatus, including the hand fire-engine,
+which is familiar to us, and is still used in many of our smaller
+cities, are described, the greater number of which are probably
+attributable to Ctesibius. They demand no description here.
+
+A hot-air engine, however, which is the subject of his 37th
+proposition, is of real interest.
+
+Hero sketches and describes a method of opening temple-doors by the
+action of fire on an altar, which is an ingenious device, and contains
+all the elements of the machine of the Marquis of Worcester, which is
+generally considered the first real steam-engine, with the single and
+vital defect that the expanding fluid is air instead of steam. The
+sketch, from Greenwood's translation, exhibits the device very
+plainly. Beneath the temple-doors, in the space _A B C D_, is placed a
+spherical vessel, _H_, containing water. A pipe, _F G_, connects the
+upper part of this sphere with the hollow and air-tight shell of the
+altar above, _D E_. Another pipe, _K L M_, leads from the bottom of
+the vessel, _H_, over, in syphon-shape, to the bottom of a suspended
+bucket, _N X_. The suspending cord is carried over a pulley and led
+around two vertical barrels, _O P_, turning on pivots at their feet,
+and carrying the doors above. Ropes led over a pulley, _R_, sustain a
+counterbalance, _W_.
+
+[Illustration: FIG. 1.--Opening Temple-Doors by Steam, B. C. 200.]
+
+On building a fire on the altar, the heated air within expands, passes
+through the pipe, _F G_, and drives the water contained in the vessel,
+_H_, through the syphon, _K L M_, into the bucket, _N X_. The weight
+of the bucket, which then descends, turns the barrels, _O P_, raises
+the counterbalance, and opens the doors of the temple. On
+extinguishing the fire, the air is condensed, the water returns
+through the syphon from the bucket to the sphere, the counterbalance
+falls, and the doors are closed.
+
+Another contrivance is next described, in which the bucket is replaced
+by an air-tight bag, which, expanding as the heated air enters it,
+contracts vertically and actuates the mechanism, which in other
+respects is similar to that just described.
+
+In these devices the spherical vessel is a perfect anticipation of
+the vessels used many centuries later by several so-called inventors
+of the steam-engine.
+
+Proposition 45 describes the familiar experiment of a ball supported
+aloft by a jet of fluid. In this example steam is generated in a close
+cauldron, and issues from a pipe inserted in the top, the ball dancing
+on the issuing jet.
+
+No. 47 is a device subsequently reproduced--perhaps reinvented by the
+second Marquis of Worcester.
+
+[Illustration: FIG. 2.--Steam Fountain, B. C. 200.]
+
+A strong, close vessel, _A B C D_, forms a pedestal, on which are
+mounted a spherical vessel, _E F_, and a basin. A pipe, _H K_, is led
+from the bottom of the larger vessel into the upper part of the
+sphere, and another pipe from the lower part of the latter, in the
+form of a syphon, over to the basin, _M_. A drain-pipe, _N O_, leads
+from the basin to the reservoir, _A D_. The whole contrivance is
+called "A fountain which is made to flow by the action of the sun's
+rays."
+
+It is operated thus: The vessel, _E F_, being filled nearly to the top
+with water, or other liquid, and exposed to the action of the sun's
+rays, the air above the water expands, and drives the liquid over,
+through the syphon, _G_, into the basin, _M_, and it will fall into
+the pedestal, _A B C D_.
+
+Hero goes on to state that, on the removal of the sun's rays, the air
+in the sphere will contract, and that the water will be returned to
+the sphere from the pedestal. This can, evidently, only occur when the
+pipe _G_ is closed previous to the commencement of this cooling. No
+such cock is mentioned, and it is not unlikely that the device only
+existed on paper.
+
+Several steam-boilers are described, usually simple pipes or
+cylindrical vessels, and the steam generated in them by the heat of
+the fire on the altar forms a steam-blast. This blast is either
+directed into the fire, or it "makes a blackbird sing," blows a horn
+for a triton, or does other equally useless work. In one device, No.
+70, the steam issues from a reaction-wheel revolving in the horizontal
+plane, and causes dancing images to circle about the altar. A more
+mechanical and more generally-known form of this device is that which
+is frequently described as the "First Steam Engine." The sketch from
+Stuart is similar in general form, but more elaborate in detail, than
+that copied by Greenwood, which is here also reproduced, as
+representing more accurately the simple form which the mechanism of
+the "AEolipile," or Ball of AEolus, assumed in those early times.
+
+[Illustration: FIG. 3.--Hero's Engine, B. C. 200.]
+
+The cauldron, _A B_, contains water, and is covered by the steam-tight
+cover, _C D_. A globe is supported above the cauldron by a pair of
+tubes, terminating, the one, _C M_, in a pivot, _L_, and the other,
+_E F_, opening directly into the sphere at _G_. Short, bent pipes, _H_
+and _K_, issue from points diametrically opposite each other, and are
+open at their extremities.
+
+A fire being made beneath the cauldron, steam is formed and finds exit
+through the pipe, _E F G_, into the globe, and thence rushes out of
+the pipes, _H K_, turning the globe on its axis, _G L_, by the
+unbalanced pressure thus produced.
+
+The more elaborate sketch which forms the frontispiece represents a
+machine of similar character. Its design and ornamentation illustrate
+well the characteristics of ancient art, and the Greek idea of the
+steam-engine.
+
+This "AEolipile" consisted of a globe, _X_, suspended between
+trunnions, _O S_, through one of which steam enters from the boiler,
+_P_, below. The hollow, bent arms, _W_ and _Z_, cause the vapor to
+issue in such directions that the reaction produces a rotary movement
+of the globe, just as the rotation of reaction water-wheels is
+produced by the outflowing water.
+
+It is quite uncertain whether this machine was ever more than a toy,
+although it has been supposed by some authorities that it was actually
+used by the Greek priests for the purpose of producing motion of
+apparatus in their temples.
+
+It seems sufficiently remarkable that, while the power of steam had
+been, during all the many centuries that man has existed upon the
+globe, so universally displayed in so many of the phenomena of natural
+change, that mankind lived almost up to the Christian era without
+making it useful in giving motion even to a toy; but it excites still
+greater surprise that, from the time of Hero, we meet with no good
+evidence of its application to practical purposes for many hundreds of
+years.
+
+Here and there in the pages of history, and in special treatises, we
+find a hint that the knowledge of the force of steam was not lost; but
+it is not at all to the credit of biographers and of historians, that
+they have devoted so little time to the task of seeking and recording
+information relating to the progress of this and other important
+inventions and improvements in the mechanic arts.
+
+Malmesbury states[7] that, in the year A. D. 1125, there existed at
+Rheims, in the church of that town, a clock designed or constructed by
+Gerbert, a professor in the schools there, and an organ blown by air
+escaping from a vessel in which it was compressed "by heated water."
+
+  [7] Stuart's "Anecdotes."
+
+Hieronymus Cardan, a wonderful mathematical genius, a most eccentric
+philosopher, and a distinguished physician, about the middle of the
+sixteenth century called attention, in his writings, to the power of
+steam, and to the facility with which a vacuum can be obtained by its
+condensation. This Cardan was the author of "Cardan's Formula," or
+rule for the solution of cubic equations, and was the inventor of the
+"smoke-jack." He has been called a "philosopher, juggler, and madman."
+He was certainly a learned mathematician, a skillful physician, and a
+good mechanic.
+
+Many traces are found, in the history of the sixteenth century, of the
+existence of some knowledge of the properties of steam, and some
+anticipation of the advantages to follow its application. Matthesius,
+A. D. 1571, in one of his sermons describes a contrivance which may be
+termed a steam-engine, and enlarges on the "tremendous results which
+may follow the volcanic action of a small quantity of confined
+vapor;"[8] and another writer applied the steam aeolipile of Hero to
+turn the spit, and thus rivaled and excelled Cardan, who was
+introducing his "smoke-jack."
+
+  [8] "Berg-Postilla, oder Sarepta von Bergwerk und Metallen."
+  Nuremberg, 1571.
+
+As Stuart says, the inventor enumerated its excellent qualities with
+great minuteness. He claimed that it would "eat nothing, and giving,
+withal, an assurance to those partaking of the feast, whose
+suspicious natures nurse queasy appetites, that the haunch has not
+been pawed by the turnspit in the absence of the housewife's eye, for
+the pleasure of licking his unclean fingers."[9]
+
+  [9] "History of the Steam-Engine," 1825.
+
+Jacob Besson, a Professor of Mathematics and Natural Philosophy at
+Orleans, and who was in his time distinguished as a mechanician, and
+for his ingenuity in contriving illustrative models for use in his
+lecture-room, left evidence, which Beroaldus collected and published
+in 1578,[10] that he had found the spirit of his time sufficiently
+enlightened to encourage him to pay great attention to applied
+mechanics and to mechanism. There was at this time a marked awakening
+of the more intelligent men of the age to the value of practical
+mechanics. A scientific tract, published at Orleans in 1569, and
+probably written by Besson, describes very intelligently the
+generation of steam by the communication of heat to water, and its
+peculiar properties.
+
+  [10] "Theatrum Instrumentorum et Machinarum, Jacobi Bessoni, cum
+  Franc Beroaldus, figuarum declaratione demonstrativa." Lugduni,
+  1578.
+
+The French were now becoming more interested in mechanics and the
+allied sciences, and philosophers and literati, of native birth and
+imported by the court from other countries, were learning more of the
+nature and importance of such studies as have a bearing upon the work
+of the engineer and of the mechanic.
+
+Agostino Ramelli, an Italian of good family, a student and an artist
+when at leisure, a soldier and an engineer in busier times, was born
+and educated at Rome, but subsequently was induced to make his home in
+Paris. He published a book in 1588,[11] in which he described many
+machines, adapted to various purposes, with a skill that was only
+equaled by the accuracy and general excellence of his delineations.
+This work was produced while its author was residing at the French
+capital, supported by a pension which had been awarded him by Henry
+III. as a reward for long and faithful services.
+
+  [11] "Le diverse et artificiose machine del Capitano Agostino
+  Ramelli, del Ponte della Prefia." Paris, 1588.
+
+The books of Besson and of Ramelli are the first treatises of
+importance on general machinery, and were, for many years, at once the
+sources from which later writers drew the principal portion of their
+information in relation to machinery, and wholesome stimulants to the
+study of mechanism. These works contain descriptions of many machines
+subsequently reinvented and claimed as new by other mechanics.
+
+Leonardo da Vinci, well known as a mathematician, engineer, poet, and
+painter, of the sixteenth century, describes, it is said, a steam-gun,
+which he calls the "Architonnerre," and ascribes to Archimedes. It was
+a machine composed of copper, and seems to have had considerable
+power. It threw a ball weighing a talent. The steam was generated by
+permitting water in a closed vessel to fall on surfaces heated by a
+charcoal fire, and by its sudden expansion to eject the ball.
+
+In the year 1825, the superintendent of the royal Spanish archives at
+Simancas furnished an account which, it was said, had been there
+discovered of an attempt, made in 1543 by Blasco de Garay, a Spanish
+navy-officer under Charles V., to move a ship by paddle-wheels,
+driven, as was inferred from the account, by a steam-engine.
+
+It is impossible to say to how much credit the story is entitled, but,
+if true, it was the first attempt, so far as is now known, to make
+steam useful in developing power for practical purposes. Nothing is
+known of the form of the engine employed, it only having been stated
+that a "vessel of boiling water" formed a part of the apparatus.
+
+The account is, however, in other respects so circumstantial, that it
+has been credited by many; but it is regarded as apocryphal by the
+majority of writers upon the subject. It was published in 1826 by M.
+de Navarrete, in Zach's "Astronomical Correspondence," in the form of
+a letter from Thomas Gonzales, Director of the Royal Archives at
+Simancas, Spain.
+
+In 1601, Giovanni Battista della Porta, in a work called "Spiritali,"
+described an apparatus by which the pressure of steam might be made to
+raise a column of water. It included the application of the
+condensation of steam to the production of a vacuum into which the
+water would flow.
+
+Porta is described as a mathematician, chemist, and physicist, a
+gentleman of fortune, and an enthusiastic student of science. His home
+in Naples was a rendezvous for students, artists, and men of science
+distinguished in every branch. He invented the magic lantern and the
+camera obscura, and described it in his commentary on the
+"Pneumatica." In his work,[12] he described this machine for raising
+water, as shown in Fig. 4, which differs from one shown by Hero in the
+use of steam pressure, instead of the pressure of heated air, for
+expelling the liquid.
+
+  [12] "Pneumaticorum libri tres," etc., 4to. Naples, 1601. "I Tre
+  Libri de' Spiritali." Napoli, 1606.
+
+The retort, or boiler, is fitted to a tank from which the bent pipe
+leads into the external air. A fire being kindled under the retort,
+the steam generated rises to the upper part of the tank, and its
+pressure on the surface of the water drives it out through the pipe,
+and it is then led to any desired height. This was called by Porta an
+improved "Hero's Fountain," and was named his "Steam Fountain." He
+described with perfect accuracy the action of condensation in
+producing a vacuum, and sketched an apparatus in which the vacuum thus
+secured was filled by water forced in by the pressure of the external
+atmosphere. His contrivances were not apparently ever applied to any
+practically useful purpose. We have not yet passed out of the age of
+speculation, and are just approaching the period of application. Porta
+is, nevertheless, entitled to credit as having proposed an essential
+change in this succession, which begins with Hero, and which did not
+end with Watt.
+
+[Illustration: FIG. 4.--Porta's Apparatus, A. D. 1601.]
+
+The use of steam in Hero's fountain was as necessary a step as,
+although less striking than, any of the subsequent modifications of
+the machine. In Porta's contrivance, too, we should note particularly
+the separation of the boiler from the "forcing vessel"--a plan often
+claimed as original with later inventors, and as constituting a fair
+ground for special distinction.
+
+The rude engraving (Fig. 4) above is copied from the book of Porta,
+and shows plainly the boiler mounted above a furnace, from the door of
+which the flame is seen issuing, and above is the tank containing
+water. The opening in the top is closed by the plug, as shown, and the
+steam issuing from the boiler into the tank near the top, the water
+is driven out through the pipe at the left, leading up from the bottom
+of the tank.
+
+[Illustration: FIG. 5.--De Caus's Apparatus, A. D. 1605.]
+
+Florence Rivault, a Gentleman of the Bedchamber to Henry IV., and a
+teacher of Louis XIII., is stated by M. Arago, the French philosopher,
+to have discovered, as early as 1605, that water confined in a
+bomb-shell and there heated would explode the shell, however thick its
+walls might be made. The fact was published in Rivault's treatise on
+artillery in 1608. He says: "The water is converted into air, and its
+vaporization is followed by violent explosion."
+
+In 1615, Salomon de Caus, who had been an engineer and architect under
+Louis XIII. of France, and later in the employ of the English Prince
+of Wales, published a work at Frankfort, entitled "Les Raisons des
+Forces Mouvantes, avec diverses machines tant utile que plaisante," in
+which he illustrated his proposition, "Water will, by the aid of fire,
+mount higher than its source," by describing a machine designed to
+raise water by the expanding power of steam.
+
+In the sketch here given (Fig. 5), and which is copied from the
+original in "Les Raisons des Forces Mouvantes," etc., _A_ is the
+copper ball containing water; _B_, the cock at the extremity of the
+pipe, taking water from the bottom, _C_, of the vessel; _D_, the cock
+through which the vessel is filled. The sketch was probably made by De
+Caus's own hand.
+
+The machine of De Caus, like that of Porta, thus consisted of a metal
+vessel partly filled with water, and in which a pipe was fitted,
+leading nearly to the bottom, and open at the top. Fire being applied,
+the steam formed by its elastic force drove the water out through the
+vertical pipe, raising it to a height limited only by either the
+desire of the builder or the strength of the vessel.
+
+In 1629, Giovanni Branca, of the Italian town of Loretto, described,
+in a work[13] published at Rome, a number of ingenious mechanical
+contrivances, among which was a steam-engine (Fig. 6), in which the
+steam, issuing from a boiler, impinged upon the vanes of a horizontal
+wheel. This it was proposed to apply to many useful purposes.
+
+  [13] "Le Machine deverse del Signior Giovanni Branca, cittadino
+  Romano, Ingegniero, Architetto della Sta. Casa di Loretto." Roma,
+  MDCXXIX.
+
+At this time experiments were in progress in England which soon
+resulted in the useful application of steam-power to raising water.
+
+[Illustration: FIG. 6.--Branca's Steam-Engine, A. D. 1629.]
+
+A patent, dated January 21, 1630, was granted to David Ramseye[14] by
+Charles I., which covered a number of distinct inventions. These were:
+"1. To multiply and make saltpeter in any open field, in fower acres
+of ground, sufficient to serve all our dominions. 2. To raise water
+from low pitts by fire. 3. To make any sort of mills to goe on
+standing waters by continual motion, without help of wind, water, or
+horse. 4. To make all sortes of tapistrie without any weaving-loom, or
+waie ever yet in use in this kingdome. 5. To make boats, shippes, and
+barges to goe against strong wind and tide. 6. To make the earth more
+fertile than usual. 7. To raise water from low places and mynes, and
+coal pitts, by a new waie never yet in use. 8. To make hard iron soft,
+and likewise copper to be tuffe and soft, which is not in use in this
+kingdome. 9. To make yellow waxe white verie speedilie."
+
+  [14] Rymer's "F[oe]dera," Sanderson. Ewbank's "Hydraulics," p. 419.
+
+This seems to have been the first authentic reference to the use of
+steam in the arts which has been found in English literature. The
+patentee held his grant fourteen years, on condition of paying an
+annual fee of L3 6_s._ 8_d._ to the Crown.
+
+The second claim is distinct as an application of steam, the language
+being that which was then, and for a century and a half subsequently,
+always employed in speaking of its use. The steam-engine, in all its
+forms, was at that time known as the "fire-engine." It would seem not
+at all improbable that the third, fifth, and seventh claims are also
+applications of steam-power.
+
+Thomas Grant, in 1632, and Edward Ford, in 1640, also patented
+schemes, which have not been described in detail, for moving ships
+against wind and tide by some new and great force.
+
+Dr. John Wilkins, Bishop of Chester, an eccentric but learned and
+acute scholar, described, in 1648, Cardan's smoke-jack, the earlier
+aeolipiles, and the power of the confined steam, and suggested, in a
+humorous discourse, what he thought to be perfectly feasible--the
+construction of a flying-machine. He says: "Might not a 'high
+pressure' be applied with advantage to move wings as large as those of
+the 'ruck's' or the 'chariot'? The engineer might probably find a
+corner that would do for a coal-station near some of the 'castles'"
+(castles in the air). The reverend wit proposed the application of the
+smoke-jack to the chiming of bells, the reeling of yarn, and to
+rocking the cradle.
+
+Bishop Wilkins writes, in 1648 ("Mathematical Magic"), of aeolipiles as
+familiar and useful pieces of apparatus, and describes them as
+consisting "of some such material as may endure the fire, having a
+small hole at which they are filled with water, and out of which (when
+the vessels are heated) the air doth issue forth with a strong and
+lasting violence." "They are," the bishop adds, "frequently used for
+the exciting and contracting of heat in the melting of glasses or
+metals. They may also be contrived to be serviceable for sundry other
+pleasant uses, as for the moving of sails in a chimney-corner, the
+motion of which sails may be applied to the turning of a spit, or the
+like."
+
+Kircher gives an engraving ("Mundus Subterraneus") showing the
+last-named application of the aeolipile; and Erckern ("Aula
+Subterranea," 1672) gives a picture illustrating their application to
+the production of a blast in smelting ores. They seem to have been
+frequently used, and in all parts of Europe, during the seventeenth
+century, for blowing fires in houses, as well as in the practical work
+of the various trades, and for improving the draft of chimneys. The
+latter application is revived very frequently by the modern inventor.
+
+
+SECTION II.--THE PERIOD OF APPLICATION--WORCESTER, PAPIN, AND SAVERY.
+
+We next meet with the first instance in which the expansive force of
+steam is supposed to have actually been applied to do important and
+useful work.
+
+In 1663, Edward Somerset, second Marquis of Worcester, published a
+curious collection of descriptions of his inventions, couched in
+obscure and singular language, and called "A Century of the Names and
+Scantlings of Inventions by me already Practised."
+
+One of these inventions is an apparatus for raising water by steam.
+The description was not accompanied by a drawing, but the sketch here
+given (Fig. 7) is thought probably to resemble one of his earlier
+contrivances very closely.
+
+Steam is generated in the boiler _a_, and thence is led into the
+vessel _e_, already nearly filled with water, and fitted up like the
+apparatus of De Caus. It drives the water in a jet out through the
+pipe _f_. The vessel _e_ is then shut off from the boiler _a_, is
+again filled through the pipe _h_, and the operation is repeated.
+Stuart thinks it possible that the marquis may have even made an
+engine with a piston, and sketches it.[15] The instruments of Porta
+and of De Caus were "steam fountains," and were probably applied, if
+used at all, merely to ornamental purposes. That of the Marquis of
+Worcester was actually used for the purpose of elevating water for
+practical purposes at Vauxhall, near London.
+
+  [15] "Anecdotes of the Steam-Engine," vol. i., p. 61.
+
+[Illustration: Edward Somerset, the Second Marquis of Worcester.]
+
+How early this invention was introduced at Raglan Castle by Worcester
+is not known, but it was probably not much later than 1628. In 1647
+Dircks shows the marquis probably to have been engaged in getting out
+parts of the later engine which was erected at Vauxhall, obtaining
+his materials from William Lambert, a brass-founder. His patent was
+issued in June, 1663.
+
+[Illustration: FIG. 7.--Worcester's Steam Fountain, A. D. 1650.]
+
+We nowhere find an illustrated description of the machine, or such an
+account as would enable a mechanic to reproduce it in all its details.
+Fortunately, the cells and grooves (Fig. 9) remaining in the wall of
+the citadel of Raglan Castle indicate the general dimensions and
+arrangement of the engine; and Dircks, the biographer of the inventor,
+has suggested the form of apparatus shown in the sketch (Fig. 8) as
+most perfectly in accord with the evidence there found, and with the
+written specifications.
+
+The two vessels, _A A'_, are connected by a steam-pipe, _B B'_, with
+the boiler, _C_, behind them. _D_ is the furnace. A vertical
+water-pipe, _E_, is connected with the cold-water vessels, _A A'_, by
+the pipes, _F F'_, reaching nearly to the bottom. Water is supplied by
+the pipes, _G G'_, with valves, _a a'_, dipping into the well or
+ditch, _H_. Steam from the boiler being admitted to each vessel, _A_
+and _A'_, alternately, and there condensing, the vacuum formed permits
+the pressure of the atmosphere to force the water from the well
+through the pipes, _G_ and _G'_. While one is filling, the steam is
+forcing the charge of water from the other up the discharge-pipe, _E_.
+As soon as each is emptied, the steam is shut off from it and turned
+into the other, and the condensation of the steam remaining in the
+vessel permits it to fill again. As will be seen presently, this is
+substantially, and almost precisely, the form of engine of which the
+invention is usually attributed to Savery, a later inventor.
+
+[Illustration: FIG. 8.--Worcester's Engine, A. D. 1665.]
+
+[Illustration: FIG. 9.--Wall of Raglan Castle.]
+
+Worcester never succeeded in forming the great company which he hoped
+would introduce his invention on a scale commensurate with its
+importance, and his fate was that of nearly all inventors. He died
+poor and unsuccessful.
+
+His widow, who lived until 1681, seemed to have become as confident as
+was Worcester himself that the invention had value, and, long after
+his death, was still endeavoring to secure its introduction, but with
+equal non-success. The steam-engine had taken a form which made it
+inconceivably valuable to the world, at a time when no more efficient
+means of raising water was available at the most valuable mines than
+horse-power; but the people, greatly as it was needed, were not yet
+sufficiently intelligent to avail themselves of the great boon, the
+acceptance of which was urged upon them with all the persistence and
+earnestness which characterizes every true inventor.
+
+Worcester is described by his biographer as having been a learned,
+thoughtful, studious, and good man--a Romanist without prejudice or
+bigotry, a loyal subject, free from partisan intolerance; as a public
+man, upright, honorable, and humane; as a scholar, learned without
+being pedantic; as a mechanic, patient, skillful, persevering, and of
+wonderful ingenuity, and of clear, almost intuitive, apprehension.
+
+Yet, with all these natural advantages, reinforced as they were by
+immense wealth and influence in his earlier life, and by hardly
+lessened social and political influence when a large fortune had been
+spent in experiment, and after misfortune had subdued his spirits and
+left him without money or a home, the inventor failed to secure the
+introduction of a device which was needed more than any other.
+Worcester had attained practical success; but the period of
+speculation was but just closing, and that of the application of steam
+had not quite yet arrived.
+
+The second Marquis of Worcester stands on the record as the first
+steam-engine builder, and his death marks the termination of the first
+of those periods into which we have divided the history of the growth
+of the steam-engine.
+
+The "water-commanding engine," as its inventor called it, was the
+first instance in the history of the steam-engine in which the
+inventor is known to have "reduced his invention to practice."
+
+It is evident, however, that the invention of the separate boiler,
+important as it was, had been anticipated by Porta, and does not
+entitle the marquis to the honor, claimed for him by many English
+authorities, of being _the_ inventor of the steam-engine. Somerset was
+simply _one_ of those whose works collectively made the steam-engine.
+
+After the time of Worcester, we enter upon a stage of history which
+may properly be termed a period of application; and from this time
+forward steam continued to play a more and more important part in
+social economy, and its influence on the welfare of mankind augmented
+with a rapidly-increasing growth.
+
+The knowledge then existing of the immense expansive force of steam,
+and the belief that it was destined to submit to the control of man
+and to lend its immense power in every department of industry, were
+evidently not confined to any one nation. From Italy to Northern
+Germany, and from France to Great Britain, the distances, measured in
+time, were vastly greater then than now, when this wonderful genius
+has helped us to reduce weeks to hours; but there existed,
+notwithstanding, a very perfect system of communication, and the
+learning of every centre was promptly radiated to every other. It thus
+happened that, at this time, the speculative study of the steam-engine
+was confined to no part of Europe; inventors and experimenters were
+busy everywhere developing this promising scheme.
+
+Jean Hautefeuille, the son of a French _boulanger_, born at Orleans,
+adopted by the Duchess of Bouillon at the suggestion of De Sourdis,
+profiting by the great opportunities offered him, entered the Church,
+and became one of the most learned men and greatest mechanicians of
+his time. He studied the many schemes then brought forward by
+inventors with the greatest interest, and was himself prolific of new
+ideas.
+
+In 1678, he proposed the use of alcohol in an engine, "in such a
+manner that the liquid should evaporate and be condensed, _tour a
+tour_, without being wasted"[16]--the first recorded plan, probably,
+for surface-condensation and complete retention of the working-fluid.
+He proposed a gunpowder-engine, of which[17] he described three
+varieties.
+
+  [16] Stuart's "Anecdotes."
+
+  [17] "Pendule Perpetuelle, avec la maniere d'elever d'eau par le
+  moyen de la poudre a canon," Paris, 1678.
+
+In one of these engines he displaced the atmosphere by the gases
+produced by the explosion, and the vacuum thus obtained was utilized
+in raising water by the pressure of the air. In the second machine,
+the pressure of the gases evolved by the combustion of the powder
+acted directly upon the water, forcing it upward; and in the third
+design, the pressure of the vapor drove a piston, and this engine was
+described as fitted to supply power for many purposes. There is no
+evidence that he constructed these machines, however, and they are
+here referred to simply as indicating that all the elements of the
+machine were becoming well known, and that an ingenious mechanic,
+combining known devices, could at this time have produced the
+steam-engine. Its early appearance should evidently have been
+anticipated.
+
+Hautefeuille, if we may judge from evidence at hand, was the first to
+propose the use of a piston in a heat-engine, and his gunpowder-engine
+seems to have been the first machine which would be called a
+heat-engine by the modern mechanic. The earlier "machines" or
+"engines," including that of Hero and those of the Marquis of
+Worcester, would rather be denominated "apparatus," as that term is
+used by the physicist or the chemist, than a machine or an engine, as
+the terms are used by the engineer.
+
+Huyghens, in 1680, in a memoir presented to the Academy of Sciences,
+speaks of the expansive force of gunpowder as capable of utilization
+as a convenient and portable mechanical power, and indicates that he
+had designed a machine in which it could be applied.
+
+This machine of Huyghens is of great interest, not simply because it
+was the first gas-engine and the prototype of the very successful
+modern explosive gas-engine of Otto and Langen, but principally as
+having been the first engine which consisted of a cylinder and piston.
+The sketch shows its form. It consisted of a cylinder, _A_, a piston,
+_B_, two relief-pipes, _C C_, fitted with check-valves and a system of
+pulleys, _F_, by which the weight is raised. The explosion of the
+powder at _H_ expels the air from the cylinder. When the products of
+combustion have cooled, the pressure of the atmosphere is no longer
+counterbalanced by that of air beneath, and the piston is forced down,
+raising the weight. The plan was never put in practice, although the
+invention was capable of being made a working and possibly useful
+machine.
+
+[Illustration: FIG. 10.--Huyghens's Engine, 1680.]
+
+At about this period the English attained some superiority over their
+neighbors on the Continent in the practical application of science and
+the development of the useful arts, and it has never since been lost.
+A sudden and great development of applied science and of the useful
+arts took place during the reign of Charles II., which is probably
+largely attributable to the interest taken by that monarch in many
+branches of construction and of science. He is said to have been very
+fond of mathematics, mechanics, chemistry, and natural history, and to
+have had a laboratory erected, and to have employed learned men to
+carry on experiments and lines of research for his satisfaction. He
+was especially fond of the study and investigation of the arts and
+sciences most closely related to naval architecture and navigation,
+and devoted much attention to the determination of the best forms of
+vessels, and to the discovery of the best kinds of ship-timber. His
+brother, the Duke of York, was equally fond of this study, and was his
+companion in some of his work.
+
+Great as is the influence of the monarch, to-day, in forming the
+tastes and habits and in determining the direction of the studies and
+labors of the people, his influence was vastly more potent in those
+earlier days; and it may well be believed that the rapid strides taken
+by Great Britain from that time were, in great degree, a consequence
+of the well-known habits of Charles II., and that the nation, which
+had an exceptional natural aptitude for mechanical pursuits, should
+have been prompted by the example of its king to enter upon such a
+course as resulted in the early attainment of an advanced position in
+all branches of applied science.
+
+The appointment, under Sir Robert Moray, the superintendent of the
+laboratory of the king, of Master Mechanic, was conferred upon Sir
+Samuel Morland, a nobleman who, in his practical knowledge of
+mechanics and in his ingenuity and fruitfulness of invention, was
+apparently almost equal to Worcester. He was the son of a Berkshire
+clergyman, was educated at Cambridge, where he studied mathematics
+with great interest, and entered public life soon after. He served the
+Parliament under Cromwell, and afterward went to Geneva. He was of a
+decidedly literary turn of mind, and wrote a history of the Piedmont
+churches, which gave him great repute with the Protestant party. He
+was induced subsequently, on the accession of Charles II., to take
+service under that monarch, whose gratitude he had earned by revealing
+a plot for his assassination.
+
+He received his appointment and a baronetcy in 1660, and immediately
+commenced making experiments, partly at his own expense and partly at
+the cost of the royal exchequer, which were usually not at all
+remunerative. He built hand fire-engines of various kinds, taking
+patents on them, which brought him as small profits as did his work
+for the king, and invented the speaking-trumpet, calculating machines,
+and a capstan. His house at Vauxhall was full of curious devices, the
+products of his own ingenuity.
+
+He devoted much attention to apparatus for raising water. His devices
+seem to have usually been modifications of the now familiar
+force-pump. They attracted much attention, and exhibitions were made
+of them before the king and queen and the court. He was sent to France
+on business relating to water-works erected for King Charles, and
+while in Paris he constructed pumps and pumping apparatus for the
+satisfaction of Louis XIV. In his book,[18] published in Paris in
+1683, and presented to the king, and an earlier manuscript,[19] still
+preserved in the British Museum, Morland shows a perfect familiarity
+with the power of steam. He says, in the latter: "Water being
+evaporated by fire, the vapors require a greater space (about two
+thousand times) than that occupied by the water; and, rather than
+submit to imprisonment, it will burst a piece of ordnance. But, being
+controlled according to the laws of statics, and, by science, reduced
+to the measure of weight and balance, it bears its burden peaceably
+(like good horses), and thus may be of great use to mankind,
+especially for the raising of water, according to the following table,
+which indicates the number of pounds which may be raised six inches,
+1,800 times an hour, by cylinders half-filled with water, and of the
+several diameters and depths of said cylinders."
+
+  [18] "Elevation des Eaux par toute sorte de Machines reduite a la
+  Mesure au Poids et a la Balance, presentee a Sa Majeste Tres
+  Chretienne, par le Chevalier Morland, Gentilhomme Ordinaire de la
+  Chambre Privee et Maistre de Mechaniques du Roy de la Grande
+  Bretagne, 1683."
+
+  [19] "Les Principes de la Nouvelle Force de Feu, inventee par le
+  Chevalier Morland, l'an 1682, et presentee a Sa Majeste Tres
+  Chretienne, 1683."
+
+He then gives the following table, a comparison of which with modern
+tables proves Morland to have acquired a very considerable and
+tolerably accurate knowledge of the volume and pressure of saturated
+steam:
+
+  -------------------------+------------------------
+         CYLINDERS.        |    POUNDS.
+  -----------+-------------+----------------------
+    Diameter |    Depth    |    Weight
+    in Feet. |   in Feet.  | to be Raised.
+  -----------+-------------+----------------------
+       1     |      2      |        15
+       2     |      4      |       120
+       3     |      6      |       405
+       4     |      8      |       960
+       5     |     10      |     1,876
+       6     |     10      |     3,240
+  -----------+-------------+----------------------
+   Number of cylinders having a diameter of 6 feet
+            and a depth of 12 feet.
+             |             |
+       1     |     12      |     3,240
+       2     |     12      |     6,480
+       3     |     12      |     9,720
+       4     |     12      |    12,960
+       5     |     12      |    16,200
+       6     |     12      |    19,440
+       7     |     12      |    22,680
+       8     |     12      |    25,920
+       9     |     12      |    29,190
+      10     |     12      |    32,400
+      20     |     12      |    64,800
+      30     |     12      |    97,200
+      40     |     12      |   129,600
+      50     |     12      |   162,000
+      60     |     12      |   194,400
+      70     |     12      |   226,800
+      80     |     12      |   259,200
+      90     |     12      |   291,600
+  -----------+-------------+----------------------
+
+The rate of enlargement of volume in the conversion of water into
+steam, as given in Morland's book, appears remarkably accurate when
+compared with statements made by other early experimenters.
+Desaguliers gave the ratio of volumes at 14,000, and this was accepted
+as correct for many years, and until Watt's experiments, which were
+quoted by Dr. Robison as giving the ratio at between 1,800 and 1,900.
+Morland also states the "duty" of his engines in the same manner in
+which it is stated by engineers to-day.
+
+Morland must undoubtedly have been acquainted with the work of his
+distinguished contemporary, Lord Worcester, and his apparatus seems
+most likely to have been a modification--perhaps improvement--of
+Worcester's engine. His house was at Vauxhall, and the establishment
+set up for the king was in the neighborhood. It may be that Morland is
+to be credited with greater success in the introduction of his
+predecessor's apparatus than the inventor himself.
+
+Dr. Hutton considered this book to have been the earliest account of
+the steam-engine, and accepts the date--1682--as that of the
+invention, and adds, that "the project seems to have remained obscure
+in both countries till 1699, when Savery, who probably knew more of
+Morland's invention than he owned, obtained a patent," etc. We have,
+however, scarcely more complete or accurate knowledge of the extent of
+Morland's work, and of its real value, than of that of Worcester.
+Morland died in 1696, at Hammersmith, not far from London, and his
+body lies in Fulham church.
+
+From this time forward the minds of many mechanicians were earnestly
+at work on this problem--the raising of water by aid of steam.
+Hitherto, although many ingenious toys, embodying the principles of
+the steam-engine separately, and sometimes to a certain extent
+collectively, had been proposed, and even occasionally constructed,
+the world was only just ready to profit by the labors of inventors in
+this direction.
+
+But, at the end of the seventeenth century, English miners were
+beginning to find the greatest difficulty in clearing their shafts of
+the vast quantities of water which they were meeting at the
+considerable depths to which they had penetrated, and it had become a
+matter of vital importance to them to find a more powerful aid in that
+work than was then available. They were, therefore, by their
+necessities stimulated to watch for, and to be prepared promptly to
+take advantage of, such an invention when it should be offered them.
+
+The experiments of Papin, and the practical application of known
+principles by Savery, placed the needed apparatus in their hands.
+
+[Illustration: Thomas Savery.]
+
+THOMAS SAVERY was a member of a well-known family of Devonshire,
+England, and was born at Shilston, about 1650. He was well educated,
+and became a military engineer. He exhibited great fondness for
+mechanics, and for mathematics and natural philosophy, and gave much
+time to experimenting, to the contriving of various kinds of
+apparatus, and to invention. He constructed a clock, which still
+remains in the family, and is considered an ingenious piece of
+mechanism, and is said to be of excellent workmanship.
+
+He invented and patented an arrangement of paddle-wheels, driven by a
+capstan[20] for propelling vessels in calm weather, and spent some
+time endeavoring to secure its adoption by the British Admiralty and
+the Navy Board, but met with no success. The principal objector was
+the Surveyor of the Navy, who dismissed Savery, with a remark which
+illustrates a spirit which, although not yet extinct, is less
+frequently met with in the public service now than then: "What have
+interloping people, that have no concern with us, to do to pretend to
+contrive or invent things for us?"[21] Savery then fitted his
+apparatus into a small vessel, and exhibited its operation on the
+Thames. The invention was never introduced into the navy, however.
+
+  [20] Harris, "Lexicon Technicum," London, 1710.
+
+  [21] "Navigation Improved; or, The Art of Rowing Ships of all rates
+  in Calms, with a more Easy, Swift, and Steady Motion, than Oars
+  can," etc., etc. By Thomas Savery, Gent. London, 1698.
+
+It was after this time that Savery became the inventor of a
+steam-engine. It is not known whether he was familiar with the work of
+Worcester, and of earlier inventors. Desaguliers[22] states that he
+had read the book of Worcester, and that he subsequently endeavored to
+destroy all evidence of the anticipation of his own invention by the
+marquis by buying up all copies of the century that he could find, and
+burning them. The story is scarcely credible. A comparison of the
+drawings given of the two engines exhibits, nevertheless, a striking
+resemblance; and, assuming that of the marquis's engine to be correct,
+Savery is to be given credit for the finally successful introduction
+of the "semi-omnipotent" "water-commanding" engine of Worcester.
+
+  [22] "Experimental Philosophy," vol. ii., p. 465.
+
+The most important advance in actual construction, therefore, was made
+by Thomas Savery. The constant and embarrassing expense, and the
+engineering difficulties presented by the necessity of keeping the
+British mines, and particularly the deep pits of Cornwall, free from
+water, and the failure of every attempt previously made to provide
+effective and economical pumping-machinery, were noted by Savery, who,
+July 25, 1698, patented the design of the first engine which was ever
+actually employed in this work. A working-model was submitted to the
+Royal Society of London in 1699, and successful experiments were made
+with it. Savery spent a considerable time in planning his engine and
+in perfecting it, and states that he expended large sums of money upon
+it.
+
+Having finally succeeded in satisfying himself with its operation, he
+exhibited a model "Fire-Engine," as it was called in those days,
+before King William III. and his court, at Hampton Court, in 1698, and
+obtained his patent without delay. The title of the patent reads: "A
+grant to Thomas Savery, Gentl., of the sole exercise of a new
+invention by him invented, for raising of water, and occasioning
+motion to all sorts of mill-works, by the impellant force of fire,
+which will be of great use for draining mines, serving towns with
+water, and for the working of all sorts of mills, when they have not
+the benefit of water nor constant winds; to hold for 14 years; with
+usual clauses."
+
+Savery now went about the work of introducing his invention in a way
+which is in marked contrast with that usually adopted by the inventors
+of that time. He commenced a systematic and successful system of
+advertisement, and lost no opportunity of making his plans not merely
+known, but well understood, even in matters of detail. The Royal
+Society was then fully organized, and at one of its meetings he
+obtained permission to appear with his model "fire-engine" and to
+explain its operation; and, as the minutes read, "Mr. Savery
+entertained the Society with showing his engine to raise water by the
+force of fire. He was thanked for showing the experiment, which
+succeeded, according to expectation, and was approved of." He
+presented to the Society a drawing and specifications of his machine,
+and "The Transactions"[23] contain a copperplate engraving and the
+description of his model. It consisted of a furnace, _A_, heating a
+boiler, _B_, which was connected by pipes, _C C_, with two copper
+receivers, _D D_. There were led from the bottom of these receivers
+branch pipes, _F F_, which turned upward, and were united to form a
+rising main, or "forcing-pipe," _G_. From the top of each receiver was
+led a pipe, which was turned downward, and these pipes united to form
+a suction-pipe, which was led down to the bottom of the well or
+reservoir from which the water was to be drawn. The maximum lift
+allowable was stated at 24 feet.
+
+  [23] "Philosophical Transactions, No. 252." Weld's "Royal Society,"
+  vol. i., p. 357. Lowthorp's "Abridgment," vol. i.
+
+[Illustration: FIG. 11.--Savery's Model, 1698.]
+
+The engine was worked as follows: Steam is raised in the boiler, _B_,
+and a cock, _C_, being opened, a receiver, _D_, is filled with steam.
+Closing the cock, _C_, the steam condensing in the receiver, a vacuum
+is created, and the pressure of the atmosphere forces the water up,
+through the supply-pipe, from the well into the receiver. Opening the
+cock, _C_, again, the check-valve in the suction-pipe at _E_ closes,
+the steam drives the water out through the forcing-pipe, _G_, the
+clack-valve, _E_, on that pipe opening before it, and the liquid is
+expelled from the top of the pipe. The valve, _C_, is again closed;
+the steam again condenses, and the engine is worked as before. While
+one of the two receivers is discharging, the other is filling, as in
+the machine of the Marquis of Worcester, and thus the steam is drawn
+from the boiler with tolerable regularity, and the expulsion of water
+takes place with similar uniformity, the two systems of receivers and
+pipes being worked alternately by the single boiler.
+
+In another and still simpler little machine,[24] which he erected at
+Kensington (Fig. 12), the same general plan was adopted, combining a
+suction-pipe, _A_, 16 feet long and 3 inches in diameter; a single
+receiver, _B_, capable of containing 13 gallons; a boiler, _C_, of
+about 40 gallons capacity; a forcing-pipe, _D_, 42 feet high, with the
+connecting pipe and cocks, _E F G_; and the method of operation was as
+already described, except that _surface-condensation_ was employed,
+the cock, _F_, being arranged to shower water from the rising main
+over the receiver, as shown. Of the first engine Switzer says: "I have
+heard him say myself, that the very first time he played, it was in a
+potter's house at Lambeth, where, though it was a small engine, yet it
+(the water) forced its way through the roof, and struck off the tiles
+in a manner that surprised all the spectators."
+
+  [24] Bradley, "New Improvements of Planting and Gardening." Switzer,
+  "Hydrostatics," 1729.
+
+[Illustration: FIG. 12.--Savery's Engine, 1698.]
+
+The Kensington engine cost L50, and raised 3,000 gallons per hour,
+filling the receiver four times a minute, and required a bushel of
+coal per day. Switzer remarks: "It must be noted that this engine is
+but a small one in comparison with many others that are made for
+coal-works; but this is sufficient for any reasonable family, and
+other uses required of it in watering all middling gardens." He
+cautions the operator: "When you have raised water enough, and you
+design to leave off working the engine, take away all the fire from
+under the boiler, and open the cock (connected to the funnel) to let
+out the steam, which would otherwise, were it to remain confined,
+perhaps burst the engine."
+
+With the intention of making his invention more generally known, and
+hoping to introduce it as a pumping-engine in the mining districts of
+Cornwall, Savery wrote a prospectus for general circulation, which
+contains the earliest account of the later and more effective form of
+engine. He entitled his pamphlet "The Miner's Friend; or, A
+Description of an Engine to raise Water by Fire described, and the
+Manner of fixing it in Mines, with an Account of the several Uses it
+is applicable to, and an Answer to the Objections against it." It was
+printed in London in 1702, for S. Crouch, and was distributed among
+the proprietors and managers of mines, who were then finding the flow
+of water at depths so great as, in some cases, to bar further
+progress. In many cases, the cost of drainage left no satisfactory
+margin of profit. In one mine, 500 horses were employed raising water,
+by the then usual method of using horse-gins and buckets.
+
+The approval of the King and of the Royal Society, and the countenance
+of the mine-adventurers of England, were acknowledged by the author,
+who addressed his pamphlet to them.
+
+The engraving of the engine was reproduced, with the description, in
+Harris's "Lexicon Technicum," 1704; in Switzer's "Hydrostatics," 1729;
+and in Desaguliers's "Experimental Philosophy," 1744.
+
+The sketch which here follows is a neater engraving of the same
+machine. Savery's engine is shown in Fig. 13, as described by Savery
+himself, in 1702, in "The Miner's Friend."
+
+_L_ is the boiler in which steam is raised, and through the pipes _O
+O_ it is alternately let into the vessels _P P_.
+
+[Illustration: FIG. 13.--Savery's Engine, A. D. 1702.]
+
+Suppose it to pass into the left-hand vessel first. The valve _M_
+being closed, and _R_ being opened, the water contained in _P_ is
+driven out and up the pipe _S_ to the desired height, where it is
+discharged.
+
+The valve _R_ is then closed, and the valve in the pipe _O_; the valve
+_M_ is next opened, and condensing water is turned upon the exterior
+of _P_ by the cock _Y_, leading water from the cistern _X_. As the
+steam contained in _P_ is condensed, forming a vacuum there, a fresh
+charge of water is driven by atmospheric pressure up the pipe _T_.
+
+Meantime, steam from the boiler has been let into the right-hand
+vessel _P_, the cock _W_ having been first closed, and _R_ opened.
+
+The charge of water is driven out through the lower pipe and the cock
+_R_, and up the pipe _S_ as before, while the other vessel is
+refilling preparatory to acting in its turn.
+
+The two vessels are thus alternately charged and discharged, as long
+as is necessary.
+
+Savery's method of supplying his boiler with water was at once simple
+and ingenious.
+
+The small boiler, _D_, is filled with water from any convenient
+source, as from the stand-pipe, _S_. A fire is then built under it,
+and, when the pressure of steam in _D_ becomes greater than in the
+main boiler, _L_, a communication is opened between their lower ends,
+and the water passes, under pressure, from the smaller to the larger
+boiler, which is thus "fed" without interrupting the work. _G_ and _N_
+are _gauge-cocks_, by which the height of water in the boilers is
+determined; they were first adopted by Savery.
+
+Here we find, therefore, the first really practicable and commercially
+valuable steam-engine. Thomas Savery is entitled to the credit of
+having been the first to introduce a machine in which the power of
+heat, acting through the medium of steam, was rendered generally
+useful.
+
+It will be noticed that Savery, like the Marquis of Worcester, used a
+boiler separate from the water-reservoir.
+
+He added to the "water-commanding engine" of the marquis the system of
+_surface-condensation_, by which he was enabled to charge his vessels
+when it became necessary to refill them; and added, also, the
+secondary boiler, which enabled him to supply the working-boiler with
+water without interrupting its work.
+
+The machine was thus made capable of working uninterruptedly for a
+period of time only limited by its own decay.
+
+Savery never fitted his boilers with safety-valves, although it was
+done earlier by Papin; and in deep mines he was compelled to make use
+of higher pressures than his rudely-constructed boilers could safely
+bear.
+
+Savery's engine was used at a number of mines, and also for supplying
+water to towns; some large estates, country houses, and other private
+establishments, employed them for the same purpose. They did not,
+however, come into general use among the mines, because, according to
+Desaguliers, they were apprehensive of danger from the explosion of
+the boilers or receivers. As Desaguliers wrote subsequently: "Savery
+made a great many experiments to bring this machine to perfection, and
+did erect several which raised water very well for gentlemen's seats,
+but could not succeed for mines, or supplying towns, where the water
+was to be raised very high and in great quantities; for then the steam
+required being boiled up to such a strength as to be ready to tear all
+the vessels to pieces." "I have known Captain Savery, at York's
+buildings, to make steam eight or ten times stronger than common air;
+and then its heat was so great that it would melt common soft solder,
+and its strength so great as to blow open several joints of the
+machine; so that he was forced to be at the pains and charge to have
+all his joints soldered with spelter or hard solder."
+
+Although there were other difficulties in the application of the
+Savery engine to many kinds of work, this was the most serious one,
+and explosions did occur with fatal results. The writer just quoted
+relates, in his "Experimental Philosophy," that a man who was ignorant
+of the nature of the engine undertook to work a machine which
+Desaguliers had provided with a safety-valve to avoid this very
+danger, "and, having hung the weight at the further end of the
+steelyard, in order to collect more steam in order to make his work
+the quicker, he hung also a very heavy plumber's iron upon the end of
+the steelyard; the consequence proved fatal; for, after some time, the
+steam, not being able, with the safety-cock, to raise up the steelyard
+loaded with all this unusual weight, burst the boiler with a great
+explosion, and killed the poor man." This is probably the earliest
+record of a steam-boiler explosion.
+
+Savery proposed to use his engine for driving mills; but there is no
+evidence that he actually made such an application of the machine,
+although it was afterward so applied by others. The engine was not
+well adapted to the drainage of surface-land, as the elevation of
+large quantities of water through small heights required great
+capacity of receivers, or compelled the use of several engines for
+each case. The filling of the receivers, in such cases, also compelled
+the heating of large areas of cold and wet metallic surfaces by the
+steam at each operation, and thus made the work comparatively wasteful
+of fuel. Where used in mines, they were necessarily placed within 30
+feet or less of the lowest level, and were therefore exposed to danger
+of submergence whenever, by any accident, the water should rise above
+that level. In many cases this would result in the loss of the engine,
+and the mine would remain "drowned," unless another engine should be
+procured to pump it out. Where the mine was deep, the water was forced
+by the pressure of steam from the level of the engine-station to the
+top of the lift. This compelled the use of pressures of several
+atmospheres in many cases; and a pressure of three atmospheres, or
+about 45 pounds per square inch, was considered, in those days, as
+about the maximum pressure allowable. This difficulty was met by
+setting a separate engine at every 60 or 80 feet, and pumping the
+water from one to the other. If any one engine in the set became
+disabled, the pumping was interrupted until that one machine could be
+repaired. The size of Savery's largest boilers was not great, their
+maximum diameter not exceeding two and a half feet. This made it
+necessary to provide several of his engines, usually, for a single
+mine, and at each level. The first cost and the expense of repairs
+were exceedingly serious items. The expense and danger, either real or
+apparent, were thus sufficient to deter many from their use, and the
+old method of raising water by horse-power was adhered to.
+
+The consumption of fuel with these engines was very great. The steam
+was not generated economically, as the boilers used were of such
+simple forms as only could then be produced, and presented too little
+heating surface to secure a very complete transfer of heat from the
+gases of combustion to the water within the boiler. This waste in the
+generation of steam in these uneconomical boilers was followed by
+still more serious waste in its application, without expansion, to the
+expulsion of water from a metallic receiver, the cold and wet sides of
+which absorbed heat with the greatest avidity. The great mass of the
+liquid was not, however, heated by the steam, and was expelled at the
+temperature at which it was raised from below.
+
+Savery quaintly relates the action of his machine in "The Miner's
+Friend," and so exactly, that a better description could scarcely be
+asked: "The steam acts upon the surface of the water in the receiver,
+which surface only being heated by the steam, it does not condense,
+but the steam gravitates or presses with an elastic quality like air,
+and still increasing its elasticity or spring, until it counterpoises,
+or rather exceeds, the weight of the column of water in the
+force-pipe, which then it will necessarily drive up that pipe; the
+steam then takes some time to recover its power, but it will at last
+discharge the water out at the top of the pipe. You may see on the
+outside of the receiver how the water goes out, as well as if it were
+transparent; for, so far as the steam is contained within the vessel,
+it is dry without, and so hot as scarcely to endure the least touch of
+the hand; but so far as the water is inside the vessel, it will be
+cold and wet on the outside, where any water has fallen on it; which
+cold and moisture vanish as fast as the steam takes the place of the
+water in its descent."
+
+After Savery's death, in 1716, several of these engines were erected
+in which some improvements were introduced. Dr. Desaguliers, in 1718,
+built a Savery engine, in which he avoided some defects which he, with
+Dr. Gravesande, had noted two years earlier. They had then proposed
+to adopt the arrangement of a single receiver which had been used by
+Savery himself, as already described, finding, by experiment on a
+model which they had made for the purpose, that one could be
+discharged three times, while the same boiler would empty two
+receivers but once each. In their arrangement, the steam was shut back
+in the boiler while the receiver was filling with water, and a high
+pressure thus accumulated, instead of being turned into the second
+receiver, and the pressure thus kept comparatively low.
+
+[Illustration: FIG. 14.--Papin's Two-Way Cock.]
+
+In the engine built in 1718, Desaguliers used a spherical boiler,
+which he provided with the lever safety-valve already applied by
+Papin, and adopted a comparatively small receiver--one-fifth the
+capacity of the boiler--of slender cylindrical form, and attached a
+pipe leading the water for condensation into the vessel, and effected
+its distribution by means of the "rose," or a "sprinkling-plate," such
+as is still frequently used in modern engines having jet-condensers.
+This substitution of jet for surface-condensation was of very great
+advantage, securing great promptness in the formation of a vacuum and
+a rapid filling of the receiver. A "two-way cock" admitted steam to
+the receiver, or, being turned the other way, admitted the cold
+condensing water. The dispersion of the water in minute streams or
+drops was a very important detail, not only as securing great
+rapidity of condensation, but enabling the designer to employ a
+comparatively small receiver or condenser.
+
+The engine is shown in Fig. 15, which is copied from the "Experimental
+Philosophy" of Desaguliers.
+
+[Illustration: FIG. 15.--Engine built by Desaguliers in 1718.]
+
+The receiver, _A_, is connected to the boiler, _B_, by a steam-pipe,
+_C_, terminating at the two-way cock, _D_; the "forcing-pipe," _E_,
+has at its foot a check-valve, _F_, and the valve _G_ is a similar
+check at the head of the suction-pipe. _H_ is a strainer, to prevent
+the ingress of chips or other bodies carried to the pipe by the
+current; the cap above the valves is secured by a bridle, or stirrup,
+and screw, _I_, and may be readily removed to clear the valves or to
+renew them; _K_ is the handle of the two-way cock; _M_ is the
+injection-cock, and is kept open during the working of the engine; _L_
+is the chimney-flue; _N_ and _O_ are gauge-cocks fitted to pipes
+leading to the proper depths within the boiler, the water-line being
+somewhere between the levels of their lower ends; _P_ is a lever
+safety-valve, as first used on the "Digester" of Papin; _R_ is the
+reservoir into which the water is pumped; _T_ is the flue, leading
+spirally about the boiler from the furnace, _V_, to the chimney; _Y_
+is a cock fitted in a pipe through which the rising-main may be filled
+from the reservoir, should injection-water be needed when that pipe is
+empty.
+
+Seven of these engines were built, the first of which was made for the
+Czar of Russia. Its boiler had a capacity of "five or six hogsheads,"
+and the receiver, "holding one hogshead," was filled and emptied four
+times a minute. The water was raised "by suction" 29 feet, and forced
+by steam pressure 11 feet higher.
+
+Another engine built at about this time, to raise water 29 feet "by
+suction," and to force it 24 feet higher, made 6 "strokes" per minute,
+and, when forcing water but 6 or 8 feet, made 8 or 9 strokes per
+minute. Twenty-five years later a workman overloaded the safety-valve
+of this engine, by placing the weight at the end and then adding "a
+very heavy plumber's iron." The boiler exploded, killing the
+attendant.
+
+Desaguliers says that one of these engines, capable of raising ten
+tons an hour 38 feet, in 1728 or 1729, cost L80, exclusive of the
+piping.
+
+Blakely, in 1766, patented an improved Savery engine, in which he
+endeavored to avoid the serious loss due to condensation of the steam
+by direct contact with the water, by interposing a cushion of oil,
+which floated upon the water and prevented the contact of the steam
+with the surface of the water beneath it. He also used air for the
+same purpose, sometimes in double receivers, one supported on the
+other. These plans did not, however, prove satisfactory.
+
+Rigley, of Manchester, England, soon after erected Savery engines, and
+applied them to the driving of mills, by pumping water into
+reservoirs, from whence it returned to the wells or ponds from which
+it had been raised, turning water-wheels as it descended.
+
+Such an arrangement was in operation many years at the works of a Mr.
+Kiers, St. Pancras, London. It is described in detail, and
+illustrated, in Nicholson's "Philosophical Journal," vol. i., p. 419.
+It had a "wagon-boiler" 7 feet long, 5 wide, and 5 deep; the wheel was
+18 feet in diameter, and drove the lathes and other machinery of the
+works. In this engine Blakely's plan of injecting air was adopted. The
+injection-valve was a clack, which closed automatically when the
+vacuum was formed.
+
+The engine consumed 6 or 7 bushels of good coals, and made 10 strokes
+per minute, raising 70 cubic feet of water 14 feet, and developing
+nearly 3 horse-power.
+
+Many years after Savery's death, in 1774, Smeaton made the first
+duty-trials of engines of this kind. He found that an engine having a
+cylindrical receiver 16 inches in diameter and 22 feet high,
+discharging the water raised 14 feet above the surface of the water in
+the well, making 12 strokes, and raising 100 cubic feet per minute,
+developed 2-2/3 horse-power, and consumed 3 hundredweight of coals in
+four hours. Its duty was, therefore, 5,250,000 pounds raised one foot
+per bushel of 84 pounds of coals, or 62,500 "foot-pounds" of work per
+pound of fuel. An engine of slightly greater size gave a duty about 5
+per cent. greater.
+
+When Louis XIV. revoked the edict of Nantes, by which Henry IV. had
+guaranteed protection to the Protestants of France, the terrible
+persecutions at once commenced drove from the kingdom some of its
+greatest men. Among these was Denys Papin.
+
+It was at about this time that the influence of the atmospheric
+pressure on the boiling-point began to be observed, Dr. Hooke having
+found that the boiling-point was a fixed temperature under the
+ordinary pressure of the atmosphere, and the increase in temperature
+and pressure of steam when confined having been shown by Papin with
+his "Digester."
+
+Denys Papin was of a family which had attached itself to the
+Protestant Church; but he was given his education in the school of the
+Jesuits at Blois, and there acquired his knowledge of mathematics. His
+medical education was given him at Paris, although he probably
+received his degree at Orleans. He settled in Paris in 1672, with the
+intention of practising his profession, and devoted all his spare
+time, apparently, to the study of physics.
+
+[Illustration: Denys Papin.]
+
+Meantime, that distinguished philosopher, Huyghens, the inventor of
+the clock and of the gunpowder-engine, had been induced by the
+linen-draper's apprentice, Colbert, now the most trusted adviser of
+the king, to take up his residence in Paris, and had been made one of
+the earliest members of the Academy of Science, which was founded at
+about that time. Papin became an assistant to Huyghens, and aided him
+in his experiments in mechanics, having been introduced by Madame
+Colbert, who was also a native of Blois. Here he devised several
+modifications of the instruments of Guericke, and printed a
+description of them.[25] This little book was presented to the
+Academy, and very favorably noticed. Papin now became well known among
+contemporary men of science at Paris, and was well received
+everywhere. Soon after, in the year 1675, as stated by the _Journal
+des Savants_, he left Paris and took up his residence in England,
+where he very soon made the acquaintance of Robert Boyle, the founder,
+and of the members of the Royal Society. Boyle speaks of Papin as
+having gone to England in the hope of finding a place in which he
+could satisfactorily pursue his favorite studies.
+
+  [25] "Nouvelles Experiences du Vuide, avec la description des
+  Machines qui servent a le faire." Paris, 1674.
+
+Boyle himself had already been long engaged in the study of
+pneumatics, and had been especially interested in the investigations
+which had been original with Guericke. He admitted young Papin into
+his laboratory, and the two philosophers worked together at these
+attractive problems. It was while working with Boyle that Papin
+invented the double air-pump and the air-gun.
+
+Papin and his work had now become so well known, and he had attained
+so high a position in science, that he was nominated for membership in
+the Royal Academy, and was elected December 16, 1680. He at once took
+his place among the most talented and distinguished of the great men
+of his time.
+
+He probably invented his "Digester" while in England, and it was first
+described in a brochure written in English, under the title, "The New
+Digester." It was subsequently published in Paris.[26] This was a
+vessel, _B_ (Fig. 16), capable of being tightly closed by a screw,
+_D_, and a lid, _C_, in which food could be cooked in water raised by
+a furnace, _A_, to the temperature due to any desired safe pressure of
+steam. The pressure was determined and limited by a weight, _W_, on
+the safety-valve lever, _G_. It is probable that this essential
+attachment to the steam-boiler had previously been used for other
+purposes; but Papin is given the credit of having first made use of it
+to control the pressure of steam.
+
+  [26] "La maniere d'amollir les os et de faire cuire toutes sortes de
+  viandes," etc.
+
+[Illustration: FIG. 16.--Papin's Digester, 1680.]
+
+From England, Papin went to Italy, where he accepted membership and
+held official position in the Italian Academy of Science. Papin
+remained in Venice two years, and then returned to England. Here, in
+1687, he announced one of his inventions, which is just becoming of
+great value in the arts. He proposed to transmit power from one point
+to another, over long distances, by the now well-known "pneumatic"
+method. At the point where power was available, he exhausted a
+chamber by means of an air-pump, and, leading a pipe to the distant
+point at which it was to be utilized, there withdrew the air from
+behind a piston, and the pressure of the air upon the latter caused it
+to recede into the cylinder, in which it was fitted, raising a weight,
+of which the magnitude was proportionate to the size of the piston and
+the degree of exhaustion. Papin was not satisfactorily successful in
+his experiments; but he had created the germ of the modern system of
+pneumatic transmission of power. His disappointment at the result of
+his efforts to utilize the system was very great, and he became
+despondent, and anxious to change his location again.
+
+In 1687 he was offered the chair of Mathematics at Marburg by Charles,
+the Landgrave of Upper Hesse, and, accepting the appointment, went to
+Germany. He remained in Germany many years, and continued his
+researches with renewed activity and interest. His papers were
+published in the "Acta Eruditorum" at Leipsic, and in the
+"Philosophical Transactions" at London. It was while at Marburg that
+his papers descriptive of his method of pneumatic transmission of
+power were printed.[27]
+
+  [27] "Recueil des diverses Pieces touchant quelques Nouvelles
+  Machines et autres Sujets Philosophiques," M. D. Papin. Cassel,
+  1695.
+
+In the "Acta Eruditorum" of 1688 he exhibited a practicable plan, in
+which he exhausted the air from a set of engines or pumps by means of
+pumps situated at a long distance from the point of application of the
+power, and at the place where the prime mover--which was in this case
+a water-wheel--was erected.
+
+After his arrival at the University of Marburg, Papin exhibited
+to his colleagues in the faculty a modification of Huyghens's
+gunpowder-engine, in which he had endeavored to obtain a more perfect
+vacuum than had Huyghens in the first of these machines. Disappointed
+in this, he finally adopted the expedient of employing steam to
+displace the air, and to produce, by its condensation, the perfect
+vacuum which he sought; and he thus produced _the first steam-engine
+with a piston_, and the first piston steam-engine, in which
+condensation was produced to secure a vacuum. It was described in the
+"Acta" of Leipsic,[28] in June, 1690, under the title, "Nova Methodus
+ad vires motrices validissimas leri pretio comparandeo" ("A New Method
+of securing cheaply Motive Power of considerable Magnitude"). He
+describes first the gunpowder-engine, and continues by stating that,
+"until now, all experiments have been unsuccessful; and after the
+combustion of the exploded powder, there always remains in the
+cylinder about one-fifth its volume of air." He says that he has
+endeavored to arrive by another route at the same end; and "as, by a
+natural property of water, a small quantity of this liquid, vaporized
+by the action of heat, acquires an elasticity like that of the air,
+and returns to the liquid state again on cooling, without retaining
+the least trace of its elastic force," he thought that it would be
+easy to construct machines in which, "by means of a moderate heat, and
+without much expense," a more perfect vacuum could be produced than
+could be secured by the use of gunpowder.
+
+  [28] "Acta Eruditorum," Leipsic, 1690.
+
+[Illustration: FIG. 17.--Papin's Engine.]
+
+The first machine of Papin (Fig. 17) was very similar to the
+gunpowder-engine already described as the invention of Huyghens. In
+place of gunpowder, a small quantity of water is placed at the bottom
+of the cylinder, _A_; a fire is built beneath it, "the bottom being
+made of very thin metal," and the steam formed soon raises the piston,
+_B_, to the top, where a latch, _E_, engaging a notch in the
+piston-rod, _H_, holds it up until it is desired that it shall drop.
+The fire being removed, the steam condenses, and a vacuum is formed
+below the piston, and the latch, _E_, being disengaged, the piston is
+driven down by the superincumbent atmosphere and raises the weight
+which has been, meantime, attached to a rope, _L_, passing from the
+piston-rod over pulleys, _T T_. The machine had a cylinder two and a
+half inches in diameter, and raised 60 pounds once a minute; and Papin
+calculated that a machine of a little more than two feet diameter of
+cylinder and of four feet stroke would raise 8,000 pounds four feet
+per minute--i. e., that it would yield about one horse-power.
+
+The inventor claimed that this new machine would be found useful in
+relieving mines from water, in throwing bombs, in ship-propulsion,
+attaching revolving paddles--i. e., paddle-wheels--to the sides of the
+vessel, which wheels were to be driven by several of his engines, in
+order to secure continuous motion, the piston-rods being fitted with
+racks which were to engage ratchet-wheels on the paddle-shafts.
+
+"The principal difficulty," he says, answering anticipated objections,
+"is that of making these large cylinders."
+
+In a reprint describing his invention, in 1695, Papin gives a
+description of a "newly-invented furnace," a kind of fire-box
+steam-boiler, in which the fire, completely surrounded by water, makes
+steam so rapidly that his engine could be driven at the rate of four
+strokes per minute by the steam supplied by it.
+
+Papin also proposed the use of a peculiar form of furnace with this
+engine, which, embodying as it does some suggestions that very
+probably have since been attributed to later inventors, deserves
+special notice. In this furnace, Papin proposed to burn his fuel on a
+grate within a furnace arranged with a _down-draught_, the air
+entering above the grate, passing _down_ through the fire, and from
+the ash-pit through a side flue to the chimney. In starting the fire,
+the coal was laid on the grate, covered with wood, and the latter was
+ignited, the flame, passing downward through the coal, igniting that
+in turn, and, as claimed by Papin, the combustion was complete, and
+the formation of smoke was entirely prevented. He states, in "Acta
+Eruditorum," that the heat was intense, the saving of fuel very great,
+and that the only difficulty was to find a refractory material which
+would withstand the high temperature attained.
+
+This is the first fire-box and flue boiler of which we have record.
+The experiment is supposed to have led Papin to suggest the use of a
+hot-blast, as practised by Neilson more than a century later, for
+reducing metals from their ores.
+
+Papin made another boiler having a flue winding through the
+water-space, and presenting a heating surface of nearly 80 square
+feet. The flue had a length of 24 feet, and was about 10 inches
+square. It is not stated what were the maximum pressures carried on
+these boilers; but it is known that Papin had used very high pressures
+in his digesters--probably between 1,200 and 1,500 pounds per square
+inch.
+
+In the year 1705, Leibnitz, then visiting England, had seen a Savery
+engine, and, on his return, described it to Papin, sending him a
+sketch of the machine. Papin read the letter and exhibited the sketch
+to the Landgrave of Hesse, and Charles at once urged him to endeavor
+to perfect his own machine, and to continue the researches which he
+had been intermittently pursuing since the earlier machine had been
+exhibited in public.
+
+In a small pamphlet printed at Cassel in 1707,[29] Papin describes a
+new form of engine, in which he discards the original plan of a
+modified Huyghens engine, with tight-fitting piston and cylinder,
+raising its load by indirect action, and makes a modified Savery
+engine, which he calls the "Elector's Engine," in honor of his patron.
+This is the engine shown in the engraving, and as proposed to be used
+by him in turning a water-wheel.
+
+  [29] "Nouvelle maniere d'elever l'Eau par la Force du Feu, mis en
+  Lumiere," par D. Papin. Cassel, 1707.
+
+The sketch is that given by the inventor in his memoir. It consists
+(Fig. 18) of a steam-boiler, _a_, from which steam is led through the
+cock, _c_, to the working cylinder, _n n_. The water beneath the
+floating-piston, _h_, which latter serves simply as a cushion to
+protect the steam from sudden condensation or contact with the water,
+is forced into the vessel _r r_, which is a large air-chamber, and
+which serves to render the outflow of water comparatively uniform, and
+the discharge occurs by means of the pipe _q_, from which the water
+rises to the desired height. A fresh supply of water is introduced
+through the funnel _k_, after condensation of the steam in _n n_, and
+the operation of expulsion is repeated.
+
+[Illustration: FIG. 18.--Papin's Engine and Water-Wheel, A. D. 1707.]
+
+This machine is evidently a retrogression, and Papin, after having
+earned the honor of having invented the first steam-engine of the
+typical form which has since become so universally applied, forfeited
+that credit by his evident ignorance of its superiority over existing
+devices, and by attempting unsuccessfully to perfect the inferior
+device of another inventor.
+
+Subsequently, Papin made an attempt to apply the steam-engine to the
+propulsion of vessels, the account of which will be given in the
+chapter on Steam-Navigation.
+
+Again disappointed, Papin once more visited England, to renew his
+acquaintance with the _savans_ of the Royal Society; but Boyle had
+died during the period which Papin had spent in Germany, and the
+unhappy and disheartened inventor and philosopher died in 1810,
+without having seen any one of his many devices and ingenious
+inventions a practical success.
+
+[Illustration]
+
+
+
+
+CHAPTER II.
+
+_THE STEAM-ENGINE AS A TRAIN OF MECHANISM._
+
+  "The introduction of new Inventions seemeth to be the very chief of
+  all human Actions. The Benefits of new Inventions may extend to all
+  Mankind universally; but the Good of political Achievements can
+  respect but some particular Cantons of Men; these latter do not
+  endure above a few Ages, the former forever. Inventions make all Men
+  happy, without either Injury or Damage to any one single Person.
+  Furthermore, new Inventions are, as it were, new Erections and
+  Imitations of God's own Works."--BACON.
+
+
+THE MODERN TYPE, AS DEVELOPED BY NEWCOMEN, BEIGHTON, AND SMEATON.
+
+At the beginning of the eighteenth century every element of the modern
+type of steam-engine had been separately invented and practically
+applied. The character of atmospheric pressure, and of the pressure of
+gases, had become understood. The nature of a vacuum was known, and
+the method of obtaining it by the displacement of the air by steam,
+and by the condensation of the vapor, was understood. The importance
+of utilizing the power of steam, and the application of condensation
+in the removal of atmospheric pressure, was not only recognized, but
+had been actually and successfully attempted by Morland, Papin, and
+Savery.
+
+Mechanicians had succeeded in making steam-boilers capable of
+sustaining any desired or any useful pressure, and Papin had shown how
+to make them comparatively safe by the attachment of the
+safety-valve. They had made steam-cylinders fitted with pistons, and
+had used such a combination in the development of power.
+
+It now only remained for the engineer to combine known forms of
+mechanism in a practical machine which should be capable of
+economically and conveniently utilizing the power of steam through the
+application of now well-understood principles, and by the intelligent
+combination of physical phenomena already familiar to scientific
+investigators.
+
+Every essential fact and every vital principle had been learned, and
+every one of the needed mechanical combinations had been successfully
+effected. It was only requisite that an inventor should appear,
+capable of perceiving that these known facts and combinations of
+mechanism, properly illustrated in a working machine, would present to
+the world its greatest physical blessing.
+
+The defects of the simple engines constructed up to this time have
+been noted as each has been described. None of them could be depended
+upon for safe, economical, and continuous work. Savery's was the most
+successful of all. But the engine of Savery, even with the
+improvements of Desaguliers, was unsafe where most needed, because of
+the high pressures necessarily carried in its boilers when pumping
+from considerable depths; it was uneconomical, in consequence of the
+great loss of heat in its forcing-cylinders when the hot steam was
+surrounded at its entrance by colder bodies; it was slow in operation,
+of great first cost, and expensive in first cost and in repairs, as
+well as in its operation. It could not be relied upon to do its work
+uninterruptedly, and was thus in many respects a very unsatisfactory
+machine.
+
+The man who finally effected a combination of the elements of the
+modern steam-engine, and produced a machine which is unmistakably a
+true engine--i. e., a train of mechanism consisting of several
+elementary pieces combined in a train capable of transmitting a force
+applied at one end and of communicating it to the resistance to be
+overcome at the other end--was THOMAS NEWCOMEN, an "iron-monger" and
+blacksmith of Dartmouth, England. The engine invented by him, and
+known as the "Atmospheric Steam-Engine," is the first of an entirely
+new type.
+
+The old type of engine--the steam-engine as a simple machine--had been
+given as great a degree of perfection, by the successive improvements
+of Worcester, Savery, and Desaguliers, as it was probably capable of
+attaining by any modification of its details. The next step was
+necessarily a complete change of type; and to effect such a change, it
+was only necessary to combine devices already known and successfully
+tried.
+
+But little is known of the personal history of Newcomen. His position
+in life was humble, and the inventor was not then looked upon as an
+individual of even possible importance in the community. He was
+considered as one of an eccentric class of schemers, and of an order
+which, concerning itself with mechanical matters, held the lowest
+position in the class.
+
+It is supposed that Savery's engine was perfectly well known to
+Newcomen, and that the latter may have visited Savery at his home in
+Modbury, which was but fifteen miles from the residence of Newcomen.
+It is thought, by some biographers of these inventors, that Newcomen
+was employed by Savery in making the more intricate forgings of his
+engine. Harris, in his "Lexicon Technicum," states that drawings of
+the engine of Savery came into the hands of Newcomen, who made a model
+of the machine, set it up in his garden, and then attempted its
+improvement; but Switzer says that Newcomen "was as early in his
+invention as Mr. Savery was in his."
+
+Newcomen was assisted in his experiments by John Calley, who, with
+him, took out the patent. It has been stated that a visit to Cornwall,
+where they witnessed the working of a Savery engine, first turned
+their attention to the subject; but a friend of Savery has stated
+that Newcomen was as early with his general plans as Savery.
+
+After some discussion with Calley, Newcomen entered into
+correspondence with Dr. Hooke, proposing a steam-engine to consist of
+a _steam-cylinder containing a piston similar to that of Papin's, and
+to drive a separate pump_, similar to those generally in use where
+water was raised by horse or wind power. Dr. Hooke advised and argued
+strongly against their plan, but, fortunately, the obstinate belief of
+the unlearned mechanics was not overpowered by the disquisitions of
+their distinguished correspondent, and Newcomen and Calley attempted
+an engine on their peculiar plan. This succeeded so well as to induce
+them to continue their labors, and, in 1705, to patent,[30] in
+combination with Savery--who held the exclusive right to practise
+surface-condensation, and who induced them to allow him an interest
+with them--an engine combining a steam-cylinder and piston,
+surface-condensation, a separate boiler, and separate pumps.
+
+  [30] It has been denied that a patent was issued, but there is no
+  doubt that Savery claimed and received an interest in the new
+  engine.
+
+In the atmospheric-engine, as first designed, the slow process of
+condensation by the application of the condensing water to the
+exterior of the cylinder, to produce the vacuum, caused the strokes of
+the engine to take place at very long intervals. An improvement was,
+however, soon effected, which immensely increased the rapidity of
+condensation. A jet of water was thrown directly _into_ the cylinder,
+thus effecting for the Newcomen engine just what Desaguliers had done
+for the Savery engine previously. As thus improved, the Newcomen
+engine is shown in Fig. 19.
+
+Here _b_ is the boiler. Steam passes from it through the cock, _d_,
+and up into the cylinder, _a_, equilibrating the pressure of the
+atmosphere, and allowing the heavy pump-rod, _k_, to fall, and, by
+the greater weight acting through the beam, _i i_, to raise the
+piston, _s_, to the position shown. The rod _m_ carries a
+counterbalance, if needed. The cock _d_ being shut, _f_ is then
+opened, and a jet of water from the reservoir, _g_, enters the
+cylinder, producing a vacuum by the condensation of the steam. The
+pressure of the air above the piston now forces it down, again raising
+the pump-rods, and thus the engine works on indefinitely.
+
+[Illustration: FIG. 19.--Newcomen's Engine, A. D. 1705.]
+
+The pipe _h_ is used for the purpose of keeping the upper side of the
+piston covered with water, to prevent air-leaks--a device of Newcomen.
+Two gauge-cocks, _c c_, and a safety-valve, _N_, are represented in
+the figure, but it will be noticed that the latter is quite different
+from the now usual form. Here, the pressure used was hardly greater
+than that of the atmosphere, and the weight of the valve itself was
+ordinarily sufficient to keep it down. The condensing water, together
+with the water of condensation, flows off through the open pipe _p_.
+Newcomen's first engine made 6 or 8 strokes a minute; the later and
+improved engines made 10 or 12.
+
+The steam-engine has now assumed a form that somewhat resembles the
+modern machine.
+
+The Newcomen engine is seen at a glance to have been a combination of
+earlier ideas. It was the engine of Huyghens, with its cylinder and
+piston as improved by Papin, by the substitution of steam for the
+gases generated by the explosion of gunpowder; still further improved
+by Newcomen and Calley by the addition of the method of condensation
+used in the Savery engine. It was further modified, with the object of
+applying it directly to the working of the pumps of the mines by the
+introduction of the overhead beam, from which the piston was suspended
+at one end and the pump-rod at the other.
+
+The advantages secured by this combination of inventions were many and
+manifest. The piston not only gave economy by interposing itself
+between the impelling and the resisting fluid, but, by affording
+opportunity to make the area of piston as large as desired, it enabled
+Newcomen to use any convenient pressure and any desired proportions
+for any proposed lift. The removal of the water to be lifted from the
+steam-engine proper and handling it with pumps, was an evident cause
+of very great economy of steam.
+
+The disposal of the water to be raised in this way also permitted the
+operations of condensation of steam, and the renewal of pressure on
+the piston, to be made to succeed each other with rapidity, and
+enabled the inventor to choose, unhampered, the device for securing
+promptly the action of condensation.
+
+Desaguliers, in his account of the introduction of the engine of
+Newcomen, says that, with his coadjutor Calley, he "made several
+experiments in private about the year 1710, and in the latter end of
+the year 1711 made proposals to drain the water of a colliery at
+Griff, in Warwickshire, where the proprietors employed 500 horses, at
+an expense of L900 a year; but, their invention not meeting with the
+reception they expected, in March following, through the acquaintance
+of Mr. Potter, of Bromsgrove, in Worcestershire, they bargained to
+draw water for Mr. Back, of Wolverhampton, where, after a great many
+laborious attempts, they did make the engine work; but, not being
+either philosophers to understand the reason, or mathematicians enough
+to calculate the powers and proportions of the parts, they very
+luckily, by accident, found what they sought for.
+
+"They were at a loss about the pumps, but, being so near Birmingham,
+and having the assistance of so many admirable and ingenious workmen,
+they came, about 1712, to the method of making the pump-valves,
+clacks, and buckets, whereas they had but an imperfect notion of them
+before. One thing is very remarkable: as they were at first working,
+they were surprised to see the engine go several strokes, and very
+quick together, when, after a search, they found a hole in the piston,
+which let the cold water in to condense the steam in the inside of the
+cylinder, whereas, before, they had always done it on the outside.
+They used before to work with a buoy to the cylinder, inclosed in a
+pipe, which buoy rose when the steam was strong and opened the
+injection, and made a stroke; thereby they were only capable of giving
+6, 8, or 10 strokes in a minute, till a boy, named Humphrey Potter, in
+1713, who attended the engine, added (what he called a _scoggan_) a
+catch, that the beam always opened, and then it would go 15 or 16
+strokes a minute. But, this being perplexed with catches and strings,
+Mr. Henry Beighton, in an engine he had built at Newcastle-upon-Tyne
+in 1718, took them all away but the beam itself, and supplied them in
+a much better manner."
+
+In illustration of the application of the Newcomen engine to the
+drainage of mines, Farey describes a small machine, of which the pump
+is 8 inches in diameter, and the lift 162 feet. The column of water
+to be raised weighed 3,535 pounds. The steam-piston was made 2
+feet in diameter, giving an area of 452 square inches. The net
+working-pressure was assumed at 10-3/4 pounds per square inch; the
+temperature of the water of condensation and of uncondensed vapor
+after the entrance of the injection-water being usually about 150 deg.
+Fahr. This gave an excess of pressure on the steam-side of 1,324
+pounds, the total pressure on the piston being 4,859 pounds. One-half
+of this excess is counterweighted by the pump-rods, and by weight on
+that end of the beam; and the weight, 662 pounds, acting on each side
+alternately as a surplus, produced the requisite rapidity of movement
+of the machine. This engine was said to make 15 strokes per minute,
+giving a speed of piston of 75 feet per minute, and the power exerted
+usefully was equivalent to 265,125 pounds raised one foot high per
+minute. As the horse-power is equivalent to 33,000 "foot-pounds" per
+minute, the engine was of 265125/33000 = 8.034--almost exactly 8
+horse-power.
+
+It is instructive to contrast this estimate with that made for a
+Savery engine doing the same work. The latter would have raised the
+water about 26 feet in its "suction-pipe," and would then have forced
+it, by the direct pressure of steam, the remaining distance of 136
+feet; and the steam-pressure required would have been nearly 60 pounds
+per square inch. With this high temperature and pressure, the waste of
+steam by condensation in the forcing-vessels would have been so great
+that it would have compelled the adoption of two engines of
+considerable size, each lifting the water one-half the height, and
+using steam of about 25 pounds pressure. Potter's rude valve-gear was
+soon improved by Henry Beighton, in an engine which that talented
+engineer erected at Newcastle-upon-Tyne in 1718, and in which he
+substituted substantial materials for the cords, as in Fig. 20.
+
+In this sketch, _r_ is a plug-tree, plug-rod, or plug-frame, as it is
+variously called, suspended from the great beam, with which it rises
+and falls, bringing the pins _p_ and _k_, at the proper moment, in
+contact with the handles _k k_ and _n n_ of the valves, moving them in
+the proper direction and to the proper extent. A lever safety-valve is
+here used, at the suggestion, it is said, of Desaguliers. The piston
+was packed with leather or with rope, and lubricated with tallow.
+
+[Illustration: FIG. 20.--Beighton's Valve-Gear, A. D. 1718.]
+
+After the death of Beighton, the atmospheric engine of Newcomen
+retained its then standard form for many years, and came into
+extensive use in all the mining districts, particularly in Cornwall,
+and was also applied occasionally to the drainage of wet lands, to the
+supply of water to towns, and it was even proposed by Hulls to be used
+for ship-propulsion.
+
+The proportions of the engines had been determined in a hap-hazard
+way, and they were in many cases very unsafe. John Smeaton, the most
+distinguished engineer of his time, finally, in 1769, experimentally
+determined proper proportions, and built several of these engines of
+very considerable size. He built his engines with steam-cylinders of
+greater length of stroke than had been customary, and gave them such
+dimensions as, by giving a greater excess of pressure on the
+steam-side, enabled him to obtain a greatly-increased speed of piston.
+The first of his new style of engine was erected at Long Benton, near
+Newcastle-upon-Tyne, in 1774.
+
+Fig. 21[31] illustrates its principal characteristic features. The
+boiler is not shown.
+
+  [31] A fac-simile of a sketch in Galloway's "On the Steam-Engine,"
+  etc.
+
+The steam is led to the engine through the pipe, _C_, and is regulated
+by turning the cock in the receiver, _D_, which connects with the
+steam-cylinder by the pipe, _E_, which latter pipe rises a little way
+above the bottom of the cylinder, _F_, in order that it may not drain
+off the injection-water into the steam-pipe and receiver.
+
+The steam-cylinder, about ten feet in length, is fitted with a
+carefully-made piston, _G_, having a flanch rising four or five inches
+and extending completely around its circumference, and nearly in
+contact with the interior surface of the cylinder. Between this flanch
+and the cylinder is driven a "packing" of oakum, which is held in
+place by weights; this prevents the leakage of air, water, or steam,
+past the piston, as it rises and falls in the cylinder at each stroke
+of the engine. The chain and piston-rod connect the piston to the
+beam, _I I_. The arch-heads at each end of the beam keep the chains of
+the piston-rod and the pump-rods perpendicular and in line.
+
+[Illustration: FIG. 21.--Smeaton's Newcomen Engine.]
+
+A "jack-head" pump, _N_, is driven by a small beam deriving its motion
+from the plug-rod at _g_, raises the water required for condensing
+the steam, and keeps the cistern, _O_, supplied. This "jack-head
+cistern" is sufficiently elevated to give the water entering the
+cylinder the velocity requisite to secure prompt condensation. A
+waste-pipe carries away any surplus water. The injection-water is led
+from the cistern by the pipe, _P P_, which is two or three inches in
+diameter, and the flow of water is regulated by the injection-cock,
+_r_. The cap at the end, _d_, is pierced with several holes, and the
+stream thus divided rises in jets when admitted, and, striking the
+lower side of the piston, the spray thus produced very rapidly
+condenses the steam, and produces a vacuum beneath the piston. The
+valve, _e_, on the upper end of the injection-pipe, is a check-valve,
+to prevent leakage into the engine when the latter is not in
+operation. The little pipe, _f_, supplies water to the upper side of
+the piston, and, keeping it flooded, prevents the entrance of air when
+the packing is not perfectly tight.
+
+The "working-plug," or plug-rod, _Q_, is a piece of timber slit
+vertically, and carrying pins which engage the handles of the valves,
+opening and closing them at the proper times. The steam-cock, or
+regulator, has a handle, _h_, by which it is moved. The iron rod, _i
+i_, or spanner, gives motion to the handle, _h_.
+
+The vibrating lever, _k l_, called the _Y_, or the "tumbling-bob,"
+moves on the pins, _m n_, and is worked by the levers, _o p_, which in
+turn are moved by the plug-tree. When _o_ is depressed, the loaded
+end, _k_, is given the position seen in the sketch, and the leg _l_ of
+the _Y_ strikes the spanner, _i i_, and, opening the steam-valve, the
+piston at once rises as steam enters the cylinder, until another pin
+on the plug-rod raises the piece, _P_, and closes the regulator again.
+The lever, _q r_, connects with the injection-cock, and is moved,
+when, as the piston rises, the end, _q_, is struck by a pin on the
+plug-rod, and the cock is opened and a vacuum produced. The cock is
+closed on the descent of the plug-tree with the piston. An
+eduction-pipe, _R_, fitted with a clock, conveys away the water in the
+cylinder at the end of each down-stroke; the water thus removed is
+collected in the hot-well, _S_, and is used as feed-water for the
+boiler, to which it is conveyed by the pipe _T_. At each down-stroke,
+while the water passes out through _R_, the air which may have
+collected in the cylinder is driven out through the "snifting-valve,"
+_s_. The steam-cylinder is supported on strong beams, _t t_; it has
+around its upper edge a guard, _v_, of lead, which prevents the
+overflow of the water on the top of the piston. The excess of this
+water flows away to the hot-well through the pipe _W_.
+
+Catch-pins, _x_, are provided, to prevent the beam descending too far
+should the engine make too long a stroke; two wooden springs, _y y_,
+receive the blow. The great beam is carried on sectors, _z z_, to
+diminish losses by friction.
+
+The boilers of Newcomen's earlier engines were made of copper where in
+contact with the products of combustion, and their upper parts were of
+lead. Subsequently, sheet-iron was substituted. The steam-space in the
+boiler was made of 8 or 10 times the capacity of the cylinder of the
+engine. Even in Smeaton's time, a chimney-damper was not used, and the
+supply of steam was consequently very variable. In the earlier
+engines, the cylinder was placed on the boiler; afterward, they were
+placed separately, and supported on a foundation of masonry. The
+injection or "jack-head" cistern was placed from 12 to 30 feet above
+the engine, the velocity due the greater altitude being found to give
+the most perfect distribution of the water and the promptest
+condensation.
+
+[Illustration: FIG. 22.--Boiler of Newcomen's Engine, 1768.]
+
+Smeaton covered the lower side of his steam-pistons with wooden plank
+about 2-1/4 inches thick, in order that it should absorb and waste
+less heat than when the iron was directly exposed to the steam. Mr.
+Beighton was the first to use the water of condensation for feeding
+the boiler, taking it directly from the eduction-pipe, or the
+"hot-well." Where only a sufficient amount of pure water could be
+obtained for feeding the boiler, and the injection-water was "hard,"
+Mr. Smeaton applied a heater, immersed in the hot-well, through which
+the feed passed, absorbing heat from the water of condensation _en
+route_ to the boiler. Farey first proposed the use of the
+"coil-heater"--a pipe, or "worm," which, forming a part of the
+feed-pipe, was set in the hot-well.
+
+As early as 1743, the metal used for the cylinders was cast-iron. The
+earlier engines had been fitted with brass cylinders. Desaguliers
+recommended the iron cylinders, as being smoother, thinner, and as
+having less capacity for heat than those of brass.
+
+In a very few years after the invention of Newcomen's engine it had
+been introduced into nearly all large mines in Great Britain; and many
+new mines, which could not have been worked at all previously, were
+opened, when it was found that the new machine could be relied upon to
+raise the large quantities of water to be handled. The first engine in
+Scotland was erected in 1720 at Elphinstone, in Stirlingshire. One was
+put up in Hungary in 1723.
+
+The first mine-engine, erected in 1712 at Griff, was 22 inches in
+diameter, and the second and third engines were of similar size. That
+erected at Ansthorpe was 23 inches in diameter of cylinder, and it was
+a long time before much larger engines were constructed. Smeaton and
+others finally made them as large as 6 feet in diameter.
+
+In calculating the lifting-power of his engines, Newcomen's method was
+"to square the diameter of the cylinder in inches, and, cutting off
+the last figure, he called it 'long hundredweights;' then writing a
+cipher on the right hand, he called the number on that side 'odd
+pounds;' this he reckoned tolerably exact at a mean, or rather when
+the barometer was above 30 inches, and the air heavy." In allowing for
+frictional and other losses, he deducted from one-fourth to one-third.
+Desaguliers found the rule quite exact. The usual mean pressure
+resisting the motion of the piston averaged, in the best engines,
+about 8 pounds per square inch of its area. The speed of the piston
+was from 150 to 175 feet per minute. The temperature of the hot-well
+was from 145 deg. to 175 deg. Fahr.
+
+Smeaton made a number of test-trials of Newcomen engines to determine
+their "duty"--i. e., to ascertain the expenditure of fuel required to
+raise a definite quantity of water to a stated height. He found an
+engine 10 inches in diameter of cylinder, and of 3 feet stroke, could
+do work equal to raising 2,919,017 pounds of water one foot high, with
+a bushel of coals weighing 84 pounds.
+
+One of Smeaton's larger engines, erected at Long Benton, was 52 inches
+in diameter of cylinder and of 7 feet stroke of piston, and made 12
+strokes per minute. Its load was equal to 7-1/2 pounds per square inch
+of piston-area, and its effective capacity about 40 horse-power. Its
+duty was 9-1/2 millions of pounds raised one foot high per bushel of
+coals. Its boiler evaporated 7.88 pounds of water per pound of fuel
+consumed. It had 35 square feet of grate-surface and 142 square feet
+of heating-surface beneath the boilers, and 317 square feet in the
+flues--a total of 459 square feet. The moving parts of this engine
+weighed 8-1/2 tons.
+
+Smeaton erected one of these engines at the Chasewater mine, in
+Cornwall, in 1775, which was of very considerable size. It was 6 feet
+in diameter of steam-cylinder, and had a maximum stroke of piston of
+9-1/2 feet. It usually worked 9 feet. The pumps were in three lifts of
+about 100 feet each, and were 16-3/4 inches in diameter. Nine strokes
+were made per minute. This engine replaced two others, of 64 and of 62
+inches diameter of cylinder respectively, and both of 6 feet stroke.
+One engine at the lower lift supplied the second, which was set above
+it. The lower one had pumps 18-1/2 inches in diameter, and raised the
+water 144 feet; the upper engine raised the water 156 feet, by pumps
+17-1/2 inches in diameter. The later engine replacing them exerted
+76-1/2 horse-power. There were three boilers, each 15 feet in
+diameter, and having each 23 square feet of grate-surface. The chimney
+was 22 feet high. The great beam, or "lever," of this engine was built
+up of 20 beams of fir in two sets, placed side by side, and ten deep,
+strongly bolted together. It was over 6 feet deep at the middle and 5
+feet at the ends, and was 2 feet thick. The "main centres," or
+journals, on which it vibrated were 8-1/2 inches in diameter and 8-1/2
+inches long. The cylinder weighed 6-1/2 tons, and was paid for at the
+rate of 28 shillings per hundredweight.
+
+By the end of the eighteenth century, therefore, the engine of
+Newcomen, perfected by the ingenuity of Potter and of Beighton, and by
+the systematic study and experimental research of Smeaton, had become
+a well-established form of steam-engine, and its application to
+raising water had become general. The coal-mines of Coventry and of
+Newcastle had adopted this method of drainage; and the tin and the
+copper mines of Cornwall had been deepened, using, for drainage,
+engines of the largest size.
+
+Some engines had been set up in and about London, the scene of
+Worcester's struggles and disappointments, where they were used to
+supply water to large houses. Others were in use in other large cities
+of England, where water-works had been erected.
+
+Some engines had also been erected to drive mills indirectly by
+raising water to turn water-wheels. This is said by Farey to have been
+first practised in 1752, at a mill near Bristol, and became common
+during the next quarter of a century. Many engines had been built in
+England and sent across the channel, to be applied to the drainage of
+mines on the Continent. Belidor[32] stated that the manufacture of
+these "fire-engines" was exclusively confined to England; and this
+remained true many years after his time. When used for the drainage of
+mines, the engine usually worked the ordinary lift or bucket pump;
+when employed for water-supply to cities, the force or plunger pump
+was often employed, the engine being placed below the level of the
+reservoir. Dr. Rees states that this engine was in common use among
+the collieries of England as early as 1725.
+
+  [32] "Architecture Hydraulique," 1734.
+
+The Edmonstone colliery was licensed, in 1725, to erect an engine, not
+to exceed 28 inches diameter of cylinder and 9 feet stroke of piston,
+paying a royalty of L80 per annum for eight years. This engine was
+built in Scotland, by workmen sent from England, and cost about
+L1,200. Its "great cost" is attributed to an extensive use of brass.
+The workmen were paid their expenses and 15_s._ per week as wages. The
+builders were John and Abraham Potter, of Durham. An engine built in
+1775, having a steam-cylinder 48 inches in diameter and of 7 feet
+stroke, cost about L2,000.
+
+Smeaton found 57 engines at work near Newcastle in 1767, ranging in
+size from 28 to 75 inches in diameter of cylinder, and of,
+collectively, about 1,200 horse-power. Fifteen of these engines gave
+an average of 98 square inches of piston to the horse-power, and the
+average duty was 5,590,000 pounds raised 1 foot high by 1 bushel (84
+pounds) of coal. The highest duty noted was 7.44 millions; the lowest
+was 3.22 millions. The most efficient engine had a steam-cylinder 42
+inches in diameter; the load was equivalent to 9-1/4 pounds per square
+inch of piston-area, and the horse-power developed was calculated to
+be 16.7.
+
+Price, writing in 1778, says, in the Appendix to his "Mineralogia
+Cornubiensis:" "Mr. Newcomen's invention of the fire-engine enabled us
+to sink our mines to twice the depth we could formerly do by any other
+machinery. Since this invention was completed, most other attempts at
+its improvement have been very unsuccessful; but the vast consumption
+of fuel in these engines is an immense drawback on the profit of our
+mines, for every fire-engine of magnitude consumes L3,000 worth of
+coals per annum. This heavy tax amounts almost to a prohibition."
+
+Smeaton was given the description, in 1773, of a _stone_ boiler, which
+was used with one of these engines at a copper mine at Camborne, in
+Cornwall. It contained three copper flues 22 inches in diameter. The
+gases were passed through these flues successively, finally passing
+off to the chimney. This boiler was cemented with hydraulic mortar. It
+was 20 feet long, 9 feet wide, and 8-1/2 feet deep. It was heated by
+the waste heat from the roasting-furnaces. This was one of the
+earliest flue-boilers ever made.
+
+In 1780, Smeaton had a list of 18 large engines working in Cornwall.
+The larger number of them were built by Jonathan Hornblower and John
+Nancarron. At this time, the largest and best-known pumping-engine for
+water-works was at York Buildings, in Villiers Street, Strand, London.
+It had been in operation since 1752, and was erected beside one of
+Savery's engines, built in 1710. It had a steam-cylinder 45 inches in
+diameter, and a stroke of piston of 8 feet, making 7-1/2 strokes per
+minute, and developing 35-1/2 horse-power. Its boiler was dome-shaped,
+of copper, and contained a large central fire-box and a spiral flue
+leading outward to the chimney. Another somewhat larger machine was
+built and placed beside this engine, some time previous to 1775. Its
+cylinder was 49 inches in diameter, and its stroke 9 feet. It raised
+water 102 feet. This engine was altered and improved by Smeaton in
+1777, and continued in use until 1813.
+
+Smeaton, as early as 1765, designed a _portable_ engine,[33] in which
+he supported the machinery on a wooden frame mounted on short legs and
+strongly put together, so that the whole machine could be transported
+and set at work wherever convenient.
+
+  [33] Smeaton's "Reports," vol. i., p. 223.
+
+[Illustration: FIG. 23.--Smeaton's Portable-Engine Boiler, 1765.]
+
+In place of the beam, a large pulley was used, over which a chain was
+carried, connecting the piston with the pump-rod, and the motion was
+similar to that given by the discarded beam. The wheel was supported
+on A-frames, resembling somewhat the "gallows-frames" still used with
+the beam-engines of American river-boats. The sills carrying the two
+A's supported the cylinder. The injection-cistern was supported above
+the great pulley-wheel. The valve-gearing and the injection-pump were
+worked by a smaller wheel, mounted on the same axis with the larger
+one. The boiler was placed apart from the engine, with which it was
+connected by a steam-pipe, in which was placed the "regulator," or
+throttle-valve. The boiler (Fig. 23) "was shaped like a large
+tea-kettle," and contained a fire-box, _B_, or internal furnace, of
+which the sides were made of cast-iron. The fire-door, _C_, was placed
+on one side and opposite the flue, _D_, through which the products of
+combustion were led to the chimney, _E_; a short, large pipe, _F_,
+leading downward from the furnace to the outside of the boiler, was
+the ash-pit. The shell of the boiler, _A_, was made of iron plate
+one-quarter of an inch thick. The steam-cylinder of the engine was 18
+inches in diameter, the stroke of piston 6 feet, the great wheel 6-1/2
+feet in diameter, and the A-frames 9 feet high. The boiler was made 6
+feet, the furnace 34 inches, and the grate 18 inches in diameter. The
+piston was intended to make 10 strokes per minute, and the engine to
+develop 4-1/8 horse-power.
+
+In 1773, Smeaton prepared plans for a pumping-engine to be set up at
+Cronstadt, the port of St. Petersburg, to empty the great dry dock
+constructed by Peter the Great and Catherine, his successor. This
+great dock was begun in 1719. It was large enough to dock ten of the
+ships of that time, and had previously been imperfectly drained by two
+great windmills 100 feet high. So imperfectly did they do their work,
+that a _year_ was required to empty the dock, and it could therefore
+only be used once in each summer. The engine was built at the Carron
+Iron Works, in England. It had a cylinder 66 inches in diameter, and a
+stroke of piston of 8-1/2 feet. The lift varied from 33 feet when the
+dock was full to 53 feet when it was cleared of water. The load on the
+engine averaged about 8-1/3 pounds per square inch of piston-area.
+There were three boilers, each 10 feet in diameter, and 16 feet 4
+inches high to the apex of its hemispherical dome. They contained
+internal fire-boxes with grates of 20 feet area, and were surrounded
+by flues helically traversing the masonry setting. The engine was
+started in 1777, and worked very successfully.
+
+The lowlands of Holland were, before the time of Smeaton, drained by
+means of windmills. The uncertainty and inefficiency of this method
+precluded its application to anything like the extent to which
+steam-power has since been utilized. In 1440, there were 150 inland
+lakes, or "_meers_," in that country, of which nearly 100, having an
+extent of over 200,000 acres, have since been drained. The "Haarlemmer
+Meer" alone covers nearly 50,000 acres, and forms the basin of a
+drainage-area of between 200,000 and 300,000 acres, receiving a
+rainfall of 54,000,000 tons, which must be raised 16 feet in
+discharging it. The beds of these lakes are from 10 to 20 feet lower
+than the water-level in the adjacent canals. In 1840, 12,000 windmills
+were still employed in this work. In the following year, William II.,
+at the suggestion of a commission, decreed that only steam-engines
+should be employed to do this immense work. Up to this time the
+average consumption of fuel for the pumping-engines in use is said to
+have been 20 pounds per hour per horse-power.
+
+The first engine used was erected in 1777 and 1778, on the Newcomen
+plan, to assist the 34 windmills employed to drain a lake near
+Rotterdam. This lake covered 7,000 acres, and its bed was 12 feet
+below the surface of the river Meuse, which passes it, and empties
+into the sea in the immediate neighborhood. The iron parts of the
+engine were built in England, and the machine was put together in
+Holland. The steam-cylinder was 52 inches in diameter, and the stroke
+of piston 9 feet. The boiler was 18 feet in diameter, and contained a
+double flue. The main beam was 27 feet long. The pumps were 6 in
+number, 3 cylindrical and 3 having a square cross-section; 3 were of 6
+feet and 3 of 2-1/2 feet stroke. Two pumps only were worked at
+high-tide, and the others were added one at a time, as the tide fell,
+until, at low-tide, all 6 were at work.
+
+The size of this engine, and the magnitude of its work, seem
+insignificant when compared with the machinery installed 60 years
+later to drain the Haarlemmer Meer, and with the work done by the
+last. These engines are 12 feet in diameter of cylinder and 10 feet
+stroke of piston, and work--they are 3 in number--the one 11 pumps of
+63 inches diameter and 10 feet stroke, the others 8 pumps of 73 inches
+diameter and of the same length of stroke. The modern engines do a
+"duty" of 75,000,000 to 87,000,000 with 94 pounds of coal, consuming
+2-1/4 pounds of coal per hour and per horse-power.
+
+The first steam-engine applied to working the blowing-machinery of a
+blast-furnace was erected at the Carron Iron-Works, in Scotland, near
+Falkirk, in 1765, and proved very unsatisfactory. Smeaton
+subsequently, in 1769 or 1770, introduced better machinery into these
+works and improved the old engine, and this use of the steam-engine
+soon became usual. This engine did its work indirectly, furnishing
+water, by pumping, to drive the water-wheels which worked the
+blowing-cylinders. Its steam-cylinder was 6 feet in diameter, and the
+pump-cylinder 52 inches. The stroke was 9 feet.
+
+A direct-acting engine, used as a blowing-engine, was not constructed
+until about 1784, at which time a single-acting blowing-cylinder, or
+air-pump, was placed at the "out-board" end of the beam, where the
+pump-rod had been attached. The piston of the air-cylinder was loaded
+with the weights needed to force it down, expelling the air, and the
+engine did its work in raising the loaded piston, the air-cylinder
+filling as the piston rose. A large "accumulator" was used to equalize
+the pressure of the expelled air. This consisted of another
+air-cylinder, having a loaded piston which was left free to rise and
+fall. At each expulsion of air by the blowing-engine this cylinder was
+filled, the loaded piston rising to the top. While the piston of the
+former was returning, and the air-cylinder was taking in its charge of
+air, the accumulator would gradually discharge the stored air, the
+piston slowly falling under its load. This piston was called the
+"floating piston," or "fly-piston," and its action was, in effect,
+precisely that of the upper portion of the common blacksmith's
+bellows.
+
+Dr. Robison, the author of "Mechanical Philosophy," one of the very
+few works even now existing deserving such a title, describes one of
+these engines[34] as working in Scotland in 1790. It had a
+steam-cylinder 40 or 44 inches in diameter, a blowing-cylinder 60
+inches in diameter, and the stroke of piston was 6 feet. The
+air-pressure was 2.77 pounds per square inch as a maximum in the
+blowing-cylinder; and the floating piston in the regulating-cylinder
+was loaded with 2.63 pounds per square inch. Making 15 or 18 strokes
+per minute, this engine delivered about 1,600 cubic feet of air, or
+120-1/2 pounds in weight, per minute, and developed 20 horse-power.
+
+  [34] "Encyclopaedia Britannica," 1st edition.
+
+At about the same date a change was made in the blowing-cylinder. The
+air entered at the bottom, as before, but was forced out at the top,
+the piston being fitted with valves, as in the common lifting-pump,
+and the engine thus being arranged to do the work of expulsion during
+the down-stroke of the steam-piston.
+
+Four years later, the regulating-cylinder, or accumulator, was given
+up, and the now familiar "water-regulator" was substituted for it.
+This consists of a tank, usually of sheet-iron, set open-end downward
+in a large vessel containing water. The lower edge of the inner tank
+is supported on piers a few inches above the bottom of the large one.
+The pipe carrying air from the blowing-engine passes above this
+water-regulator, and a branch-pipe is led down into the inner tank. As
+the air-pressure varies, the level of the water within the inverted
+tank changes, rising as pressure falls at the slowing of the motion of
+the piston, and falling as the pressure rises again while the piston
+is moving with an accelerated velocity. The regulator, thus receiving
+surplus air to be delivered when needed, greatly assists in regulating
+the pressure. The larger the regulator, the more perfectly uniform the
+pressure. The water-level outside the inner tank is usually five or
+six feet higher than within it. This apparatus was found much more
+satisfactory than the previously-used regulator, and, with its
+introduction, the establishment of the steam-engine as a
+blowing-engine for iron-works and at blast-furnaces may be considered
+as having been fully established.
+
+Thus, by the end of the third quarter of the eighteenth century, the
+steam-engine had become generally introduced, and had been applied to
+nearly all of the purposes for which a single-acting engine could be
+used. The path which had been opened by Worcester had been fairly laid
+out by Savery and his contemporaries, and the builders of the Newcomen
+engine, with such improvements as they had been able to effect, had
+followed it as far as they were able. The real and practical
+introduction of the steam-engine is as fairly attributable to Smeaton
+as to any one of the inventors whose names are more generally known in
+connection with it. As a mechanic, he was unrivaled; as an engineer,
+he was head and shoulders above any constructor of his time engaged in
+general practice. There were very few important public works built in
+Great Britain at that time in relation to which he was not consulted;
+and he was often visited by foreign engineers, who desired his advice
+with regard to works in progress on the Continent.
+
+[Illustration]
+
+
+
+
+CHAPTER III.
+
+_THE DEVELOPMENT OF THE MODERN STEAM-ENGINE. JAMES WATT AND HIS
+CONTEMPORARIES._
+
+  The world is now entering upon the Mechanical Epoch. There is
+  nothing in the future more sure than the great triumphs which that
+  epoch is to achieve. It has already advanced to some glorious
+  conquests. What miracles of invention now crowd upon us! Look
+  abroad, and contemplate the infinite achievements of the
+  steam-power.
+
+  And yet we have only begun--we are but on the threshold of this
+  epoch.... What is it but the setting of the great distinctive seal
+  upon the nineteenth century?--an advertisement of the fact that
+  society has risen to occupy a higher platform than ever before?--a
+  proclamation from the high places, announcing honor, honor immortal,
+  to the workmen who fill this world with beauty, comfort, and
+  power--honor to be forever embalmed in history, to be perpetuated in
+  monuments, to be written in the hearts of this and succeeding
+  generations!--KENNEDY.
+
+
+SECTION I.--JAMES WATT AND HIS INVENTIONS.
+
+The success of the Newcomen engine naturally attracted the attention
+of mechanics, and of scientific men as well, to the possibility of
+making other applications of steam-power.
+
+The best men of the time gave much attention to the subject, but,
+until James Watt began the work that has made him famous, nothing more
+was done than to improve the proportions and slightly alter the
+details of the Newcomen and Calley engine, even by such skillful
+engineers as Brindley and Smeaton. Of the personal history of the
+earlier inventors and improvers of the steam-engine, very little is
+ascertained; but that of Watt has become well known.
+
+[Illustration: James Watt.]
+
+JAMES WATT was of an humble lineage, and was born at Greenock, then a
+little Scotch fishing village, but now a considerable and a busy town,
+which annually launches upon the waters of the Clyde a fleet of
+steamships whose engines are probably, in the aggregate, far more
+powerful than were all the engines in the world at the date of Watt's
+birth, January 19, 1736. His grandfather, Thomas Watt, of
+Crawfordsdyke, near Greenock, was a well-known mathematician about the
+year 1700, and was for many years a schoolmaster at that place. His
+father was a prominent citizen of Greenock, and was at various times
+chief magistrate and treasurer of the town. James Watt was a bright
+boy, but exceedingly delicate in health, and quite unable to attend
+school regularly, or to apply himself closely to either study or play.
+His early education was given by his parents, who were respectable and
+intelligent people, and the tools borrowed from his father's
+carpenter-bench served at once to amuse him and to give him a
+dexterity and familiarity with their use that must undoubtedly have
+been of inestimable value to him in after-life.
+
+M. Arago, the eminent French philosopher, who wrote one of the
+earliest and most interesting biographies of Watt, relates anecdotes
+of him which, if correct, illustrate well his thoughtfulness and his
+intelligence, as well as the mechanical bent of the boy's mind. He is
+said, at the age of six years, to have occupied himself during leisure
+hours with the solution of geometrical problems; and Arago discovers,
+in a story in which he is described as experimenting with the
+tea-kettle,[35] his earliest investigations of the nature and
+properties of steam.
+
+  [35] The same story is told of Savery and of Worcester.
+
+When finally sent to the village school, his ill health prevented his
+making rapid progress; and it was only when thirteen or fourteen years
+of age that he began to show that he was capable of taking the lead in
+his class, and to exhibit his ability in the study, particularly, of
+mathematics. His spare time was principally spent in sketching with
+his pencil, in carving, and in working at the bench, both in wood and
+metal. He made many ingenious pieces of mechanism, and some beautiful
+models. His favorite work seemed to be the repairing of nautical
+instruments. Among other pieces of apparatus made by the boy was a
+very fine barrel-organ. In boyhood, as in after-life, he was a
+diligent reader, and seemed to find something to interest him in every
+book that came into his hands.
+
+At the age of eighteen, Watt was sent to Glasgow, there to
+reside with his mother's relatives, and to learn the trade of a
+mathematical-instrument maker. The mechanic with whom he was placed
+was soon found too indolent, or was otherwise incapable of giving
+much aid in the project, and Dr. Dick, of the University of Glasgow,
+with whom Watt became acquainted, advised him to go to London.
+Accordingly, he set out in June, 1755, for the metropolis, where, on
+his arrival, he arranged with Mr. John Morgan, in Cornhill, to work a
+year at his chosen business, receiving as compensation 20 guineas. At
+the end of the year he was compelled, by serious ill-health, to return
+home.
+
+Having become restored to health, he went again to Glasgow in 1756,
+with the intention of pursuing his calling there. But, not being the
+son of a burgess, and not having served his apprenticeship in the
+town, he was forbidden by the guilds, or trades-unions, to open a shop
+in Glasgow. Dr. Dick came to his aid, and employed him to repair some
+apparatus which had been bequeathed to the college. He was finally
+allowed the use of three rooms in the University building, its
+authorities not being under the municipal rule. He remained here until
+1760, when, the trades no longer objecting, he took a shop in the
+city; and in 1761 moved again, into a shop on the north side of the
+Trongate, where he earned a scanty living without molestation, and
+still kept up his connection with the college. He did some work as a
+civil engineer in the neighborhood of Glasgow, but soon gave up all
+other employment, and devoted himself entirely to mechanics.
+
+He spent much of his leisure time--of which he had, at first, more
+than was desirable--in making philosophical experiments and in the
+manufacture of musical instruments, in making himself familiar with
+the sciences, and in devising improvements in the construction of
+organs. In order to pursue his researches more satisfactorily, he
+studied German and Italian, and read Smith's "Harmonics," that he
+might become familiar with the principles of construction of musical
+instruments. His reading was still very desultory; but the
+introduction of the Newcomen engine in the neighborhood of Glasgow,
+and the presence of a model in the college collections, which was
+placed in his hands, in 1763, for repair, led him to study the history
+of the steam-engine, and to conduct for himself an experimental
+research into the properties of steam, with a set of improvised
+apparatus.
+
+Dr. Robison, then a student of the University, who found Watt's shop a
+pleasant place in which to spend his leisure, and whose tastes
+affiliated so strongly with those of Watt that they became friends
+immediately upon making acquaintance, called the attention of the
+instrument-maker to the steam-engine as early as 1759, and suggested
+that it might be applied to the propulsion of carriages. Watt was at
+once interested, and went to work on a little model, having tin
+steam-cylinders and pistons connected to the driving-wheels by an
+intermediate system of gearing. The scheme was afterwards given up,
+and was not revived by Watt for a quarter of a century.
+
+Watt studied chemistry, and was assisted by the advice and instruction
+of Dr. Black, who was then making the researches which resulted in the
+discovery of "latent heat." His proposal to repair the model Newcomen
+engine in the college collections led to his study of Desaguliers's
+treatise, and of the works of Switzer and others. He thus learned what
+had been done by Savery and by Newcomen, and by those who had improved
+the engine of the latter.
+
+In his own experiments he used, at first, apothecaries' phials and
+hollow canes for steam reservoirs and pipes, and later a Papin's
+digester and a common syringe. The latter combination made a
+non-condensing engine, in which he used steam at a pressure of 15
+pounds per square inch. The valve was worked by hand, and Watt saw
+that an automatic valve-gear only was needed to make a working
+machine. This experiment, however, led to no practical result. He
+finally took hold of the Newcomen model, which had been obtained from
+London, where it had been sent for repairs, and, putting it in good
+working order, commenced experiments with that.
+
+The Newcomen model, as it happened, had a boiler which, although made
+to a scale from engines in actual use, was quite incapable of
+furnishing steam enough to work the engine. It was about nine inches
+in diameter; the steam-cylinder was two inches in diameter, and of six
+inches stroke of piston, arranged as in Fig. 24, which is a picture of
+the model as it now appears. It is retained among the most
+carefully-preserved treasures of the University of Glasgow.
+
+[Illustration: FIG. 24.--The Newcomen Model.]
+
+Watt made a new boiler for the experimental investigation on which he
+was about to enter, and arranged it in such a manner that he could
+measure the quantity of water evaporated and of steam used at every
+stroke of the engine.
+
+He soon discovered that it required but a very small quantity of steam
+to heat a very large quantity of water, and immediately attempted to
+determine with precision the relative weights of steam and water in
+the steam-cylinder when condensation took place at the down-stroke of
+the engine, and thus independently proved the existence of that
+"latent heat," the discovery of which constitutes, also, one of the
+greatest of Dr. Black's claims to distinction. Watt at once went to
+Dr. Black and related the remarkable fact which he had thus detected,
+and was, in turn, taught by Black the character of the phenomenon as
+it had been explained to his classes by the latter some little time
+previously. Watt found that, at the boiling-point, his steam,
+condensing, was capable of heating six times its weight of water such
+as was used for producing condensation.
+
+Perceiving that steam, weight for weight even, was a vastly greater
+absorbent and reservoir of heat than water, Watt saw plainly the
+importance of taking greater care to economize it than had previously
+been customary. He first attempted to economize in the boiler, and
+made boilers with wooden "shells," in order to prevent losses by
+conduction and radiation, and used a larger number of flues to secure
+more complete absorption of the heat from the furnace-gases. He also
+covered his steam-pipes with non-conducting materials, and took every
+precaution that his ingenuity could devise to secure complete
+utilization of the heat of combustion. He soon found, however, that he
+was not working at the most important point, and that the great source
+of loss was to be found in defects which he noted in the action of the
+steam in the cylinder. He soon concluded that the sources of loss of
+heat in the Newcomen engine--which would be greatly exaggerated in a
+small model--were:
+
+First, the dissipation of heat by the cylinder itself, which was of
+brass, and was both a good conductor and a good radiator.
+
+Secondly, the loss of heat consequent upon the necessity of cooling
+down the cylinder at every stroke, in producing the vacuum.
+
+Thirdly, the loss of power due to the pressure of vapor beneath the
+piston, which was a consequence of the imperfect method of
+condensation.
+
+He first made a cylinder of non-conducting material--wood soaked in
+oil and then baked--and obtained a decided advantage in economy of
+steam. He then conducted a series of very accurate experiments upon
+the temperature and pressure of steam at such points on the scale as
+he could readily reach, and, constructing a curve with his results,
+the abscesses representing temperatures and the pressures being
+represented by the ordinates, he ran the curve backward until he had
+obtained closely-approximate measures of temperatures less than 212 deg.,
+and pressures less than atmospheric. He thus found that, with the
+amount of injection-water used in the Newcomen engine, bringing the
+temperature of the interior, as he found, down to from 140 deg. to 175 deg.
+Fahr., a very considerable back-pressure would be met with.
+
+Continuing his examination still further, he measured the amount of
+steam used at each stroke, and, comparing it with the quantity that
+would just fill the cylinder, he found that at least _three-fourths
+was wasted_. The quantity of cold water necessary to produce the
+condensation of a given weight of steam was next determined; and he
+found that one pound of steam contained enough heat to raise about six
+pounds of cold water, as used for condensation, from the temperature
+of 52 deg. to the boiling-point; and, going still further, he found that
+he was compelled to use, at each stroke of the Newcomen engine, _four
+times as much injection-water as should suffice to condense a cylinder
+full of steam_. This confirmed his previous conclusion that
+three-fourths of the heat supplied to the engine was wasted.
+
+Watt had now, therefore, determined by his own researches, as he
+himself enumerates them,[36] the following facts:
+
+  [36] Robison's "Mechanical Philosophy," edited by Brewster.
+
+"1. The capacities for heat of iron, copper, and of some sorts of
+wood, as compared with water.
+
+"2. The bulk of steam compared with that of water.
+
+"3. The quantity of water evaporated in a certain boiler by a pound of
+coal.
+
+"4. The elasticities of steam at various temperatures greater than
+that of boiling water, and an approximation to the law which it
+follows at other temperatures.
+
+"5. How much water in the form of steam was required every stroke by a
+small Newcomen engine, with a wooden cylinder 6 inches in diameter and
+12 inches stroke.
+
+"6. The quantity of cold water required in every stroke to condense
+the steam in that cylinder, so as to give it a working-power of about
+7 pounds on the square inch."
+
+After these well-devised and truly scientific investigations, Watt was
+enabled to enter upon his work of improving the steam-engine with an
+intelligent understanding of its existing defects, and with a
+knowledge of their cause. Watt soon saw that, in order to reduce the
+losses in the working of the steam in the steam-cylinder, it would be
+necessary to find some means, as he said, to keep the cylinder "always
+as hot as the steam that entered it," notwithstanding the great
+fluctuations of temperature and pressure of the steam during the up
+and the down strokes. He has told us how, finally, the happy thought
+occurred to him which relieved him of all difficulty, and led to the
+series of modifications which at last gave to the world the modern
+type of steam-engine.
+
+He says:[37] "I had gone to take a walk on a fine Sabbath afternoon. I
+had entered the Green by the gate at the foot of Charlotte street, and
+had passed the old washing-house. I was thinking upon the engine at
+the time, and had gone as far as the herd's house, when the idea came
+into my mind that, as steam was an elastic body, it would rush into a
+vacuum, and, if a communication were made between the cylinder and an
+exhausted vessel, it would rush into it, and might be there condensed
+without cooling the cylinder. I then saw that I must get rid of the
+condensed steam and injection-water if I used a jet, as in Newcomen's
+engine. Two ways of doing this occurred to me: First, the water might
+be run off by a descending pipe, if an offlet could be got at the
+depth of 35 or 36 feet, and any air might be extracted by a small
+pump. The second was, to make the pump large enough to extract both
+water and air." "I had not walked farther than the Golf-house, when
+the whole thing was arranged in my mind."
+
+  [37] "Reminiscences of James Watt," Robert Hart; "Transactions of
+  the Glasgow Archaeological Society," 1859.
+
+Referring to this invention, Watt said to Prof. Jardine:[38] "When
+analyzed, the invention would not appear so great as it seemed to be.
+In the state in which I found the steam-engine, it was no great effort
+of mind to observe that the quantity of fuel necessary to make it work
+would forever prevent its extensive utility. The next step in my
+progress was equally easy--to inquire what was the cause of the great
+consumption of fuel. This, too, was readily suggested, viz., the waste
+of fuel which was necessary to bring the whole cylinder, piston, and
+adjacent parts from the coldness of water to the heat of steam, no
+fewer than from 15 to 20 times in a minute." It was by pursuing this
+train of thought that he was led to devise the separate condenser.
+
+  [38] "Lives of Boulton and Watt," Smiles.
+
+On Monday morning Watt proceeded to make an experimental test of his
+new invention, using for his steam-cylinder and piston a large brass
+surgeon's-syringe, 1-3/4-inch diameter and 10 inches long. At each end
+was a pipe leading steam from the boiler, and fitted with a cock to
+act as a steam-valve. A pipe led also from the top of the cylinder to
+the condenser, the syringe being inverted and the piston-rod hanging
+downward for convenience. The condenser was made of two pipes of thin
+tin plate, 10 or 12 inches long, and about one-sixth of an inch in
+diameter, standing vertically, and having a connection at the top
+with a horizontal pipe of larger size, and fitted with a
+"snifting-valve." Another vertical pipe, about an inch in diameter,
+was connected to the condenser, and was fitted with a piston, with a
+view to using it as an "air-pump." The whole was set in a cistern of
+cold water. The piston-rod of the little steam-cylinder was drilled
+from end to end to permit the water to be removed from the cylinder.
+This little model (Fig. 25) worked very satisfactorily, and the
+perfection of the vacuum was such that the machine lifted a weight of
+18 pounds hung upon the piston-rod, as in the sketch. A larger model
+was immediately afterward constructed, and the result of its test
+confirmed fully the anticipations which had been awakened by the first
+experiment.
+
+[Illustration: FIG. 25.--Watt's Experiment.]
+
+Having taken this first step and made such a radical improvement, the
+success of this invention was no sooner determined than others
+followed in rapid succession, as consequences of the exigencies
+arising from the first change in the old Newcomen engine. But in the
+working out of the forms and proportions of the details of the new
+engine, even Watt's powerful mind, stored as it was with
+happily-combined scientific and practical information, was occupied
+for years. In attaching the separate condenser, he first attempted
+surface-condensation; but this not succeeding well, he substituted the
+jet. Some provision became at once necessary for preventing the
+filling of the condenser with water.
+
+Watt at first intended adopting the expedient which had worked
+satisfactorily with the less effective condensation of Newcomen's
+engine--i. e., leading a pipe from the condenser to a depth greater
+than the height of a column of water which could be counterbalanced by
+the pressure of the atmosphere; but he subsequently employed the
+air-pump, which relieves the condenser not only of the water, but of
+the air which also usually collects in considerable volume in the
+condenser, and vitiates the vacuum. He next substituted oil and tallow
+for water in the lubrication of the piston and keeping it steam-tight,
+in order to avoid the cooling of the cylinder incident to the use of
+the latter. Another cause of refrigeration of the cylinder, and
+consequent waste of power in its operation, was seen to be the
+entrance of the atmosphere, which followed the piston down the
+cylinder at each stroke, cooling its interior by its contact. This the
+inventor concluded to prevent by covering the top of the cylinder,
+allowing the piston-rod to play through a "stuffing-box"--which device
+had long been known to mechanics.
+
+He accordingly not only covered the top, but surrounded the whole
+cylinder with an external casing, or "steam-jacket," and allowed the
+steam from the boiler to pass around the steam-cylinder and to press
+upon the upper surface of the piston, where its pressure was variable
+at pleasure, and therefore more manageable than that of the
+atmosphere. It also, besides keeping the cylinder hot, could do
+comparatively little harm should it leak by the piston, as it could be
+condensed, and thus readily disposed of.
+
+When he had concluded to build the larger experimental engine, Watt
+determined to give his whole time and attention to the work, and hired
+a room in an old deserted pottery near the Broomielaw. Here he worked
+with a mechanic--John Gardiner, whom he had taken into his
+employ--uninterruptedly for many weeks. Meantime, through his friend
+Dr. Black, probably, he had made the acquaintance of Dr. Roebuck, a
+wealthy physician, who had, with other Scotch capitalists, just
+founded the celebrated Carron Iron-Works, and had opened a
+correspondence with him, in which he kept that gentleman informed of
+the progress of his work on the new engine.
+
+This engine had a steam-cylinder, Watt tells us, of "five or six"
+inches diameter, and of two feet stroke. It was of copper,
+smooth-hammered, but not bored out, and "not very true." This was
+encased in another cylinder of wood. In August, 1765, he tried the
+small engine, and wrote Dr. Roebuck that he had had "good success,"
+although the machine was very imperfect. "On turning the
+exhausting-cock, the piston, when not loaded, ascended as quick as the
+blow of a hammer, and as quick when loaded with 18 pounds (being 7
+pounds on the inch) as it would have done if it had had an injection
+as usual." He then tells his correspondent that he was about to make
+the larger model. In October, 1765, he finished the latter. The
+engine, when ready for trial, was still very imperfect. It
+nevertheless did good work for so rude a machine.
+
+Watt was now reduced to poverty, and, after borrowing considerable
+sums from friends, he was finally compelled to give up his scheme for
+the time, and to seek employment in order to provide for his family.
+During an interval of about two years he supported himself by
+surveying, and by the work of exploring coal-fields in the
+neighborhood of Glasgow for the magistrates of the city. He did not,
+however, entirely give up his invention.
+
+In 1767, Dr. Roebuck assumed Watt's liabilities to the amount of
+L1,000, and agreed to provide capital for the prosecution of his
+experiments and to introduce his invention; and, on the other hand,
+Watt agreed to surrender to Dr. Roebuck two-thirds of the patent.
+Another engine was next built, having a steam-cylinder seven or eight
+inches in diameter, which was finished in 1768. This worked
+sufficiently well to induce the partners to ask for a patent, and the
+specifications and drawings were completed and presented in 1769.
+
+Watt also built and set up several Newcomen engines, partly, perhaps,
+to make himself thus thoroughly familiar with the practical details of
+engine-building. Meantime, also, he prepared the plans for, and
+finally had built, a moderately large engine of his own new type. Its
+steam-cylinder was 18 inches in diameter, and the stroke of piston was
+5 feet. This engine was built at Kinneil, and was finished in
+September, 1769. It was not all satisfactory in either its
+construction or its operation. The condenser was a surface-condenser
+composed of pipes somewhat like that used in his first little model,
+and did not prove to be satisfactorily tight. The steam-piston leaked
+seriously, and repeated trials only served to make more evident its
+imperfections. He was assisted in this time of need by both Dr. Black
+and Dr. Roebuck; but he felt strongly the risks which he ran of
+involving his friends in serious losses, and became very despondent.
+Writing to Dr. Black, he says: "Of all things in life, there is
+nothing more foolish than inventing;" and probably the majority of
+inventors have been led to the same opinion by their own experiences.
+
+"Misfortunes never come singly;" and Watt was borne down by the
+greatest of all misfortunes--the loss of a faithful and affectionate
+wife--while still unable to see a successful issue of his schemes.
+Only less disheartening than this was the loss of fortune of his
+steadfast friend, Dr. Roebuck, and the consequent loss of his aid. It
+was at about this time, in the year 1769, that negotiations were
+commenced which resulted in the transfer of the capitalized interest
+in Watt's engine to the wealthy manufacturer whose name, coupled with
+that of Watt, afterward became known throughout the civilized world,
+as the steam-engine in its new form was pushed into use by his energy
+and business tact.
+
+Watt met Mr. Boulton, who next became his partner, in 1768, on his
+journey to London to procure his patent, and the latter had then
+examined Watt's designs, and, at once perceiving their value, proposed
+to purchase an interest. Watt was then unable to reply definitely to
+Boulton's proposition, pending his business arrangements with Dr.
+Roebuck; but, with Roebuck's consent, afterwards proposed that Boulton
+should take a one-third interest with himself and partner, paying
+Roebuck therefor one-half of all expenses previously incurred, and
+whatever he should choose to add to compensate "for the risk he had
+run." Subsequently, Dr. Roebuck proposed to transfer to Boulton and to
+Dr. Small, who was desirous of taking interest with Boulton, one-half
+of his proprietorship in Watt's inventions, on receiving "a sum not
+less than one thousand pounds," which should, after the experiments on
+the engine were completed, be deemed "just and reasonable." Twelve
+months were allowed for the adjustment of the account. This proposal
+was accepted in November, 1769.
+
+[Illustration: Matthew Boulton.]
+
+MATTHEW BOULTON, who now became a partner with James Watt, was the son
+of a Birmingham silver stamper and piecer, and succeeded to his
+father's business, building up a great establishment, which, as well
+as its proprietor, was well known in Watt's time. Watt, writing to Dr.
+Roebuck before the final arrangement had been made, urged him to close
+with Boulton for "the following considerations:
+
+"1st. From Mr. Boulton's own character as an ingenious, honest, and
+rich man. 2dly. From the difficulty and expense there would be of
+procuring accurate and honest workmen and providing them with proper
+utensils, and getting a proper overseer or overseers. If, to avoid
+this inconvenience, you were to contract for the work to be done by a
+master-workman, you must give up a great share of the profit. 3dly.
+The success of the engine is far from being verified. If Mr. Boulton
+takes his chance of success from the account I shall write Dr. Small,
+and pays you any adequate share of the money laid out, it lessens your
+risk, and in a greater proportion than I think it will lessen your
+profits. 4thly. The assistance of Mr. Boulton's and Dr. Small's
+ingenuity (if the latter engage in it) in improving and perfecting the
+machine may be very considerable, and may enable us to get the better
+of the difficulties that might otherwise damn it. Lastly, consider my
+uncertain health, my irresolute and inactive disposition, my inability
+to bargain and struggle for my own with mankind: all which disqualify
+me for any great undertaking. On our side, consider the first outlay
+and interest, the patent, the present engine, about L200 (though there
+would not be much loss in making it into a common engine), two years
+of my time, and the expense of models."
+
+Watt's estimate of the value of Boulton's ingenuity and talent was
+well-founded. Boulton had shown himself a good scholar, and had
+acquired considerable knowledge of the languages and of the sciences,
+particularly of mathematics, after leaving the school from which he
+graduated into the shop when still a boy. In the shop he soon
+introduced a number of valuable improvements, and he was always on the
+lookout for improvements made by others, with a view to their
+introduction in his business. He was a man of the modern style, and
+never permitted competitors to excel him in any respect, without the
+strongest efforts to retain his leading position. He always aimed to
+earn a reputation for good work, as well as to make money. His
+father's workshop was at Birmingham; but Boulton, after a time, found
+that his rapidly-increasing business would compel him to find room for
+the erection of a more extensive establishment, and he secured land at
+Soho, two miles distant from Birmingham, and there erected his new
+manufactory, about 1762.
+
+The business was, at first, the manufacture of ornamental metal-ware,
+such as metal buttons, buckles, watch-chains, and light filigree and
+inlaid work. The manufacture of gold and silver plated-ware was soon
+added, and this branch of business gradually developed into a very
+extensive manufacture of works of art. Boulton copied fine work
+wherever he could find it, and often borrowed vases, statuettes, and
+bronzes of all kinds from the nobility of England, and even from the
+queen, from which to make copies. The manufacture of inexpensive
+clocks, such as are now well known throughout the world as an article
+of American trade, was begun by Boulton. He made some fine
+astronomical and valuable ornamental clocks, which were better
+appreciated on the Continent than in England. The business of the Soho
+manufactory in a few years became so extensive, that its goods were
+known to every civilized nation, and its growth, under the management
+of the enterprising, conscientious, and ingenious Boulton, more than
+kept pace with the accumulation of capital; and the proprietor found
+himself, by his very prosperity, often driven to the most careful
+manipulation of his assets, and to making free use of his credit.
+
+Boulton had a remarkable talent for making valuable acquaintances, and
+for making the most of advantages accruing thereby. In 1758 he made
+the acquaintance of Benjamin Franklin, who then visited Soho; and in
+1766 these distinguished men, who were then unaware of the existence
+of James Watt, were corresponding, and, in their letters, discussing
+the applicability of steam-power to various useful purposes. Between
+the two a new steam-engine was designed, and a model was constructed
+by Boulton, which was sent to Franklin and exhibited by him in London.
+
+Dr. Darwin seems to have had something to do with this scheme, and the
+enthusiasm awakened by the promise of success given by this model may
+have been the origin of the now celebrated prophetic rhymes so often
+quoted from the works of that eccentric physician and poet. Franklin
+contributed, as his share in the plan, an idea of so arranging the
+grate as to prevent the production of smoke. He says: "All that is
+necessary is to make the smoke of fresh coals pass descending through
+those that are already ignited." His idea has been, by more recent
+schemers, repeatedly brought forward as new. Nothing resulted from
+these experiments of Boulton, Franklin, and Darwin, and the plan of
+Watt soon superseded all less well-developed plans.
+
+In 1767, Watt visited Soho and carefully inspected Boulton's
+establishment. He was very favorably impressed by the admirable
+arrangement of the workshops and the completeness of their outfit, as
+well as by the perfection of the organization and administration of
+the business. In the following year he again visited Soho, and this
+time met Boulton, who had been absent at the previous visit. The two
+great mechanics were mutually gratified by the meeting, and each at
+once acquired for the other the greatest respect and esteem. They
+discussed Watt's plans, and Boulton then definitely decided not to
+continue his own experiments, although he had actually commenced the
+construction of a pumping-engine. With Dr. Small, who was also at
+Soho, Watt discussed the possibility of applying his engine to the
+propulsion of carriages, and to other purposes. On his return home,
+Watt continued his desultory labors on his engines, as already
+described; and the final completion of the arrangement with Boulton,
+which immediately followed the failure of Dr. Roebuck, took place some
+time later.
+
+Before Watt could leave Scotland to join his partner at Soho, it was
+necessary that he should finish the work which he had in hand,
+including the surveys of the Caledonian canal, and other smaller
+works, which he had had in progress some months. He reached Birmingham
+in the spring of 1774, and was at once domiciled at Soho, where he set
+at work upon the partly-made engines which had been sent from Scotland
+some time previously. They had laid, unused and exposed to the
+weather, at Kinneil three years, and were not in as good order as
+might have been desired. The _block-tin_ steam-cylinder was probably
+in good condition, but the iron parts were, as Watt said, "perishing,"
+while he had been engaged in his civil engineering work. At leisure
+moments, during this period, Watt had not entirely neglected his plans
+for the utilization of steam. He had given much thought, and had
+expended some time, in experiments upon the plan of using it in a
+rotary or "wheel" engine. He did not succeed in contriving any plan
+which seemed to promise success.
+
+It was in November, 1774, that Watt finally announced to his old
+partner, Dr. Roebuck, the successful trial of the Kinneil engine. He
+did not write with the usual enthusiasm and extravagance of the
+inventor, for his frequent disappointments and prolonged suspense had
+very thoroughly extinguished his vivacity. He simply wrote: "The
+fire-engine I have invented is now going, and answers much better than
+any other that has yet been made; and I expect that the invention will
+be very beneficial to me."
+
+The change of the "atmospheric engine" of Newcomen into the modern
+steam-engine was now completed in its essential details. The first
+engine which was erected at Kinneil, near Boroughstoness, had a
+steam-cylinder 18 inches in diameter. It is seen in the accompanying
+sketch.
+
+[Illustration: FIG. 26.--Watt's Engine, 1774.]
+
+In Fig. 26, the steam passes from the boiler through the pipe _d_ and
+the valve _c_ to the cylinder-casing or steam-jacket, _Y Y_, and above
+the piston, _b_, which it follows in its descent in the cylinder,
+_a_, the valve _f_ being at this time open, to allow the exhaust into
+the condenser, _h_.
+
+The piston now being at the lower end of the cylinder, and the
+pump-rods at the opposite end of the beam, _y_, being thus raised and
+the pumps filled with water, the valves _c_ and _f_ close, while _e_
+opens, allowing the steam which remains above the piston to flow
+beneath it, until, the pressures becoming equal above and below, the
+weight of the pump-rods overbalancing that of the piston, the latter
+is rapidly drawn to the top of the cylinder, while the steam is
+displaced above, passing to the under-side of the piston.
+
+The valve _e_ is next closed, and _c_ and _f_ are again opened; the
+down-stroke is repeated. The water and air entering the condenser are
+removed at each stroke by the air-pump, _i_, which communicates with
+the condenser by the passage _s_. The pump _q_ supplies
+condensing-water, and the pump _A_ takes away a part of the water of
+condensation, which is thrown by the air-pump into the "hot-well,"
+_k_, and from it the feed-pump supplies the boiler. The valves are
+moved by valve-gear very similar to Beighton's and Smeaton's, by the
+pins, _m m_, in the "plug-frame" or "tappet-rod," _n n_.
+
+The engine is mounted upon a substantial foundation, _B B_. _F_ is an
+opening out of which, before starting the engine, the air is driven
+from the cylinder and condenser.
+
+The inventions covered by the patent of 1769 were described as
+follows:
+
+"My method of lessening the consumption of steam, and consequently
+fuel, in fire-engines, consists in the following principles:
+
+"1st. That the vessel in which the powers of steam are to be employed
+to work the engine--which is called 'the cylinder' in common
+fire-engines, and which I call 'the steam-vessel'--must, during the
+whole time that the engine is at work, be kept as hot as the steam
+which enters it; first, by inclosing it in a case of wood, or any
+other materials that transmit heat slowly; secondly, by surrounding
+it with steam or other heated bodies; and thirdly, by suffering
+neither water nor other substances colder than the steam to enter or
+touch it during that time.
+
+"2dly. In engines that are to be worked, wholly or partially, by
+condensation of steam, the steam is to be condensed in vessels
+distinct from the steam-vessel or cylinder, though occasionally
+communicating with them. These vessels I call condensers; and while
+the engines are working, these _condensers_ ought at least to be kept
+as cold as the air in the neighborhood of the engines, by application
+of water or other cold bodies.
+
+"3dly. Whatever air or other elastic vapor is not condensed by the
+cold of the condenser, and may impede the working of the engine, is to
+be drawn out of the steam-vessels or condensers by means of pumps,
+wrought by the engines themselves, or otherwise.
+
+"4thly. I intend in many cases to employ the expansive force of steam
+to press on the pistons, or whatever may be used instead of them, in
+the same manner as the pressure of the atmosphere is now employed in
+common fire-engines. In cases where cold water cannot be had in
+plenty, the engines may be wrought by this force of steam only, by
+discharging the steam into the open air after it has done its office.
+
+"5thly. Where motions round an axis are required, I make the
+steam-vessels in form of hollow rings or circular channels, with
+proper inlets and outlets for the steam, mounted on horizontal axles
+like the wheels of a water-mill. Within them are placed a number of
+valves that suffer any body to go round the channel in one direction
+only. In these steam-vessels are placed weights, so fitted to them as
+to fill up a part or portion of their channels, yet rendered capable
+of moving freely in them by the means hereinafter mentioned or
+specified. When the steam is admitted in these engines between these
+weights and the valves, it acts equally on both, so as to raise the
+weight on one side of the wheel, and, by the reaction of the valves
+successively, to give a circular motion to the wheel, the valves
+opening in the direction in which the weights are pressed, but not in
+the contrary. As the vessel moves round, it is supplied with steam
+from the boiler, and that which has performed its office may either be
+discharged by means of condensers, or into the open air.
+
+"6thly. I intend in some cases to apply a degree of cold not capable
+of reducing the steam to water, but of contracting it considerably, so
+that the engines shall be worked by the alternate expansion and
+contraction of the steam.
+
+"Lastly, instead of using water to render the piston or other parts of
+the engine air or steam-tight, I employ oils, wax, resinous bodies,
+fat of animals, quicksilver, and other metals, in their fluid state."
+
+In the construction and erection of his engines, Watt still had great
+difficulty in finding skillful workmen to make the parts with
+accuracy, to fit them with care, and to erect them properly when once
+finished. And the fact that both Newcomen and Watt met with such
+serious trouble, indicates that, even had the engine been designed
+earlier, it is quite unlikely that the world would have seen the
+steam-engine a success until this time, when mechanics were just
+acquiring the skill requisite for its construction. But, on the other
+hand, it is not at all improbable that, had the mechanics of an
+earlier period been as skillful and as well-educated in the manual
+niceties of their business, the steam-engine might have been much
+earlier brought into use.
+
+In the time of the Marquis of Worcester it would have probably been
+found impossible to obtain workmen to construct the steam-engine of
+Watt, had it been then invented. Indeed, Watt, upon one occasion,
+congratulated himself that one of his steam-cylinders only lacked
+_three-eighths_ of an inch of being truly cylindrical.
+
+The history of the steam-engine is from this time a history of the
+work of the firm of Boulton & Watt. Newcomen engines continued to be
+built for years after Watt went to Soho, and by many builders. A host
+of inventors still worked on the most attractive of all mechanical
+combinations, seeking to effect further improvements. Some inventions
+were made by contemporaries of Watt, as will be seen hereafter, which
+were important as being the germs of later growths; but these were
+nearly all too far in advance of the time, and nearly every successful
+and important invention which marked the history of steam-power for
+many years originated in the fertile brain of James Watt.
+
+The defects of the Newcomen engine were so serious, that it was no
+sooner known that Boulton of Soho had become interested in a new
+machine for raising water by steam-power, than inquiries came to him
+from all sides, from mine-owners who were on the point of being
+drowned out, and from proprietors whose profits were absorbed by the
+expense of pumping, and who were glad to pay the L5 per horse-power
+per year finally settled upon as royalty. The London municipal
+water-works authorities were also ready to negotiate for
+pumping-engines for raising water to supply the metropolis. The firm
+was therefore at once driven to make preparations for a large
+business.
+
+The first and most important matter, however, was to secure an
+extension of the patent, which was soon to expire. If not renewed, the
+15 years of study and toil, of poverty and anxiety, through which Watt
+had toiled, would prove profitless to the inventor, and the fruits of
+his genius would have become the unearned property of others. Watt
+saw, at one time, little hope of securing the necessary act of
+Parliament, and was greatly tempted to accept a position tendered him
+by the Russian Government, upon the solicitation of his old friend,
+Dr. Robison, then a Professor of Mathematics at the Naval School at
+Cronstadt. The salary was L1,000--a princely income for a man in
+Watt's circumstances, and a peculiar temptation to the needy
+mechanic.
+
+Watt, however, went to London, and, with the help of his own and of
+Boulton's influential friends, succeeded in getting his bill through.
+His patent was extended 24 years, and Boulton & Watt set about the
+work of introducing their engines with the industry and enterprise
+which characterized their every act.
+
+In the new firm, Boulton took charge of the general business, and Watt
+superintended the design, construction, and erection of their engines.
+Boulton's business capacity, with Watt's wonderful mechanical
+ability--Boulton's physical health, and his vigor and courage,
+offsetting Watt's feeble health and depression of spirits--and, more
+than all, Boulton's pecuniary resources, both in his own purse and in
+those of his friends, enabled the firm to conquer all difficulties,
+whether in finance, in litigation, or in engineering.
+
+It was only after the successful erection and operation of several
+engines that Boulton and Watt became legally partners. The understood
+terms were explicitly stated by Watt to include an assignment to
+Boulton of two-thirds the patent-right; Boulton paying all expenses,
+advancing stock in trade at an appraised valuation, on which it was to
+draw interest; Watt making all drawings and designs, and drawing
+one-third net profits.
+
+As soon as Watt was relieved of the uncertainties regarding his
+business connections, he married a second wife, who, as Arago says, by
+"her various talent, soundness of judgment, and strength of
+character," made a worthy companion to the large-hearted and
+large-brained engineer. Thenceforward his cares were only such as
+every business-man expects to be compelled to sustain, and the next
+ten years were the most prolific in inventions of any period in Watt's
+life.
+
+From 1775 to 1785 the partners acquired five patents, covering a large
+number of valuable improvements upon the steam-engine, and several
+independent inventions. The first of these patents covered the now
+familiar and universally-used copying-press for letters, and a
+machine for drying cloth by passing it between copper rollers filled
+with steam of sufficiently high temperature to rapidly evaporate the
+moisture. This patent was issued February 14, 1780.
+
+[Illustration: FIG. 27.--Watt's Engine, 1781.]
+
+In the following year, October 25, 1781, Watt patented five devices by
+which he obtained the rotary motion of the engine-shaft without the
+use of a crank. One of these was the arrangement shown in Fig. 27, and
+known as the "sun-and-planet" wheels. The crank-shaft carries a
+gear-wheel, which is engaged by another securely fixed upon the end of
+the connecting-rod. As the latter is compelled to revolve about the
+axis of the shaft by a tie which confines the connecting-rod end at a
+fixed distance from the shaft, the shaft-gear is compelled to revolve,
+and the shaft with it. Any desired velocity-ratio was secured by
+giving the two gears the necessary relative diameters. A fly-wheel was
+used to regulate the motion of the shaft.[39] Boulton & Watt used the
+sun-and-planet device on many engines, but finally adopted the crank,
+when the expiration of the patent held by Matthew Wasborough, and
+which had earlier date than Watt's patent of 1781, permitted them.
+Watt had proposed the use of a crank, it is said, as early as 1771,
+but Wasborough anticipated him in securing the patent. Watt had made a
+model of an engine with a crank and fly-wheel, and he has stated that
+one of his workmen, who had seen the model, described it to
+Wasborough, thus enabling the latter to deprive Watt of his own
+property. The proceeding excited great indignation on the part of
+Watt; but no legal action was taken by Boulton & Watt, as the
+overthrow of the patent was thought likely to do them injury by
+permitting its use by more active competitors and more ingenious men.
+
+  [39] For the privilege of using the fly-wheel to regulate the motion
+  of the engine, Boulton & Watt paid a royalty to Matthew Wasborough,
+  who had patented it, and who held also the patent for its
+  combination with a crank, as invented by Pickard and Steed.
+
+The next patent issued to Watt was an exceedingly important one, and
+of especial interest in a history of the development of the economical
+application of steam. This patent included:
+
+1. The expansion of steam, and six methods of applying the principle
+and of equalizing the expansive power.
+
+2. The double-acting steam-engine, in which the steam acts on each
+side of the piston alternately, the opposite side being in
+communication with the condenser.
+
+3. The double or coupled steam-engine--two engines capable of working
+together, or independently, as may be desired.
+
+4. The use of a rack on the piston-rod, working into a sector on the
+end of the beam, thus securing a perfect rectilinear motion of the
+rod.
+
+5. A rotary engine, or "steam-wheel."
+
+The efficiency to be secured by the expansion of steam had long been
+known to Watt, and he had conceived the idea of economizing some of
+that power, the waste of which was so plainly indicated by the violent
+rushing of the exhaust-steam into the condenser, as early as 1769.
+This was described in a letter to Dr. Small, of Birmingham, in May of
+that year. When experimenting at Kinneil, he had tried to determine
+the real value of the principle by trial on his small engine.
+
+Boulton had also recognized the importance of this improved method of
+working steam, and their earlier Soho engines were, as Watt said, made
+with cylinders "double the size wanted, and cut off the steam at
+half-stroke." But, though "this was a great saving of steam, so long
+as the valves remained as at first," the builders were so constantly
+annoyed by alterations of the valves by proprietors and their
+engineers, that they finally gave up that method of working, hoping
+ultimately to be able to resume it when workmen of greater
+intelligence and reliability could be found. The patent was issued
+July 17, 1782.
+
+Watt specified a cut-off at one-quarter stroke as usually best.
+
+Watt's explanation of the method of economizing by expansive working,
+as given to Dr. Small,[40] is worthy of reproduction. He says: "I
+mentioned to you a method of still doubling the effect of steam, and
+that tolerably easy, by using the power of steam rushing into a
+vacuum, at present lost. This would do a little more than double the
+effect, but it would too much enlarge the vessels to use it all. It is
+peculiarly applicable to wheel-engines, and may supply the want of a
+condenser where force of steam is only used; for, open one of the
+steam-valves and admit steam, until one-fourth of the distance between
+it and the next valve is filled with steam, shut the valve, and the
+steam will continue to expand and to pass round the wheel with a
+diminishing power, ending in one-fourth its first exertion. The sum of
+this series you will find greater than one-half, though only
+one-fourth steam was used. The power will indeed be unequal, but this
+can be remedied by a fly, or in several other ways."
+
+  [40] "Lives of Boulton and Watt," Smiles.
+
+It will be noticed that Watt suggests, above, the now well-known
+non-condensing engine. He had already, as has been seen, described it
+in his patent of 1769, as also the rotary engine.
+
+Watt illustrates and explains his idea very neatly, by a sketch
+similar to that here given (Fig. 28).
+
+Steam, entering the cylinder at _a_, is admitted until one-fourth the
+stroke has been made, when the steam-valve is closed, and the
+remainder of the stroke is performed without further addition of
+steam. The variation of steam-pressure is approximately inversely
+proportional to the variation of its volume. Thus, at half-stroke, the
+pressure becomes one-half that at which the steam was supplied to the
+cylinder. At the end of the stroke it has fallen to one-fourth the
+initial pressure. The pressure is always nearly equal to the product
+of the initial pressure and volume divided by the volume at the given
+instant. In symbols,
+
+         _PV_
+  _P'_ = ----.
+         _V'_
+
+It is true that the condensation of steam doing work changes this law
+in a marked manner; but the condensation and reevaporation of steam,
+due to the transfer of heat to and from the metal of the cylinder,
+tends to compensate the first variation by a reverse change of
+pressure with change of volume.
+
+[Illustration: FIG. 28.--Expansion of Steam.]
+
+The sketch shows this progressive variation of pressure as expansion
+proceeds. It is seen that the work done per unit of volume of steam as
+taken from the boiler is much greater than when working without
+expansion. The product of the mean pressure by the volume of the
+cylinder is less, but the quotient obtained by dividing this quantity
+by the volume or weight of steam taken from the boiler, is much
+greater with than without expansion. For the case assumed and
+illustrated, the work done during expansion is one and two-fifths
+times that done previous to cutting off the steam, and the work done
+per pound of steam is 2.4 times that done without expansion.
+
+Were there no losses to be met with and to be exaggerated by the use
+of steam expansively, the gain would become very great with moderate
+expansion, amounting to twice the work done when "following" full
+stroke, when the steam is cut off at one-seventh. The estimated gain
+is, however, never realized. Losses by friction, by conduction and
+radiation of heat, and by condensation and reevaporation in the
+cylinder--of which losses the latter are most serious--after passing a
+point which is variable, and which is determined by the special
+conditions in each case, augment with greater rapidity than the gain
+by expansion.
+
+In actual practice, it is rarely found, except where special
+precautions are taken to reduce these losses, that economy follows
+expansion to a greater number of volumes than about one-half the
+square root of the steam-pressure; i. e., about twice for 15 or 20
+pounds pressure, three times for about 30 pounds, and four and five
+times for 60 or 65 and for 100 to 125 pounds respectively. Watt very
+soon learned this general principle; but neither he, nor even many
+modern engineers, seem to have learned that too great expansion often
+gives greatly-reduced economy.
+
+The inequality of pressure due to expansion, to which he refers, was a
+source of much perplexity to Watt, as he was for a long time convinced
+that he must find some method of "equalizing" the consequent irregular
+effort of the steam upon the piston. The several methods of
+"equalizing the expansive power" which are referred to in the patent
+were attempts to secure this result. By one method, he shifted the
+centre as the beam vibrated, thus changing the lengths of the arms of
+that great lever, to compensate the change of moment consequent upon
+the change of pressure. He finally concluded that a fly-wheel, as
+first proposed by Fitzgerald, who advised its use on Papin's engine,
+would be the best device on engines driving a crank, and trusted to
+the inertia of a balance-weight in his pumping-engines, or to the
+weight of the pump-rods, and permitted the piston to take its own
+speed so far as it was not thus controlled.
+
+The double-acting engine was a modification of the single-acting
+engine, and was very soon determined upon after the successful working
+of the latter had become assured.
+
+Watt had covered in the top of his single-acting engine, to prevent
+cooling the interior of the cylinder by contact with the comparatively
+cold atmosphere. When this had been done, there was but a single step
+required to convert the machine into the double-acting engine. This
+alteration, by which the steam was permitted to act upon the upper and
+the lower sides of the piston alternately, had been proposed by Watt
+as early as 1767, and a drawing of the engine was laid before a
+committee of the House of Commons in 1774-'75. By this simple change
+Watt doubled the power of his engine. Although invented much earlier,
+the plan was not patented until he was, as he states, driven to take
+out the patent by the "plagiarists and pirates" who were always ready
+to profit by his ingenuity. This form of engine is now almost
+universally used. The single-acting pumping-engine remains in use in
+Cornwall, and in a few other localities, and now and then an engine is
+built for other purposes, in which steam acts only on one side of the
+piston; but these are rare exceptions to the general rule.
+
+The subject of his next invention was not less interesting. The
+double-cylinder or "compound" engine has now, after the lapse of
+nearly a century, become an important and usual type of engine. It is
+impossible to determine precisely to whom to award the credit of its
+first conception. Dr. Falk, in 1779, had proposed a double-acting
+engine, in which there were two single-acting cylinders, acting in
+opposite directions and alternately on opposite sides of a wheel, with
+which a rack on the piston-rod of each geared.
+
+Watt claimed that Hornblower, the patentee of the "compound engine,"
+was an infringer upon his patents; and, holding the patent on the
+separate condenser, he was able to prevent the engine of his
+competitor taking such form as to be successfully introduced. The
+Hornblower engine was soon given up.
+
+Watt stated that this form of engine had been invented by him as early
+as 1767, and that he had explained its peculiarities to Smeaton and
+others several years before Hornblower attempted to use it. He wrote
+to Boulton: "It is no less than our double-cylinder engine, worked
+upon our principle of expansion." He never made use of the plan,
+however; and the principal object sought, apparently, in patenting
+this, as well as many other devices, was to secure himself against
+competition.
+
+The rack and sector patented at this time was soon superseded by the
+parallel-motion; and the last claim, the "steam-wheel" or rotary
+engine, although one was built of considerable size, was not
+introduced.
+
+After the patent of 1782 had been secured, Watt turned his attention,
+when not too hard-pressed by business, to other schemes, and to
+experimenting with still other modifications and applications of his
+engine. He had, as early as 1777, proposed to make a steam-hammer for
+Wilkinson's forge; but he was too closely engaged with more important
+matters to take hold of the project with much earnestness until late
+in the year 1782, when, after some preliminary trials, he reported,
+December 13th: "We have tried our little tilting-forge hammer at Soho
+with success. The following are some of the particulars: Cylinder, 15
+inches in diameter; 4 feet stroke; strokes per minute, 20. The
+hammer-head, 120 pounds weight, rises 8 inches, and strikes 240 blows
+per minute. The machine goes quite regularly, and can be managed as
+easily as a water-mill. It requires a very small quantity of
+steam--not above half the contents of the cylinder per stroke. The
+power employed is not more than one-fourth of what would be required
+to raise the quantity of water which would enable a water-wheel to
+work the same hammer with the same velocity."
+
+He immediately set about making a much heavier hammer, and on April
+26, 1783, he wrote that he had done "a thing never done
+before"--making his hammer strike 300 blows a minute. This hammer
+weighed 7-1/2 hundredweight, and had a drop of 2 feet. The
+steam-cylinder had a diameter of 42 inches and 6 feet stroke of
+piston, and was calculated to have sufficient power to drive four
+hammers weighing 7 hundredweight each. The engine made 20 strokes per
+minute, the hammer giving 90 blows in the same time.
+
+This new application of steam-power proving successful, Watt next
+began to develop a series of minor inventions, which were finally
+secured by his patent of April 27, 1784, together with the steam
+tilt-hammer, and a steam-carriage, or "locomotive engine."
+
+The contrivance previously used for guiding the head of the
+piston-rod--the sectors and chains, or rack--had never given
+satisfaction. The rudeness of design of the contrivance was only
+equalled by its insecurity. Watt therefore contrived a number of
+methods of accomplishing the purpose, the most beautiful and
+widely-known of which is the "parallel-motion," although it has now
+been generally superseded by one of the other devices patented at the
+same time--the cross-head and guides. As originally proposed, a rod
+was attached to the head of the piston-rod, standing vertically when
+the latter was at quarter-stroke. The upper end of this rod was
+pivoted to the end of the beam, and the lower end to the extremity of
+a horizontal rod having a length equal to one-half the length of the
+beam. The other end of the horizontal rod was coupled to the frame of
+the engine. As the piston rose and fell, the upper and lower ends of
+the vertical rod were swayed in opposite directions, and to an equal
+extent, by the beam and the lower horizontal rod, the middle point at
+which the piston-rod was attached preserving its position in the
+vertical line. This form was objectionable, as the whole effort of the
+engine was transmitted through the parallel-motion rods. Another form
+is shown in the sketch given of the double-acting engine in Fig. 31,
+which was free from this defect. The head of the piston-rod, _g_, was
+guided by rods connecting it with the frame at _c_, and forming a
+"parallelogram," _g d e b_, with the beam. Many varieties of
+"parallel-motion" have been devised since Watt's invention was
+attached to his engines at Soho. They usually are more or less
+imperfect, guiding the piston-rod in a line only approximately
+straight.
+
+The cross-head and guides are now generally used, very much as
+described by Watt in this patent as his "second principle." This
+device will be seen in the engravings given hereafter of more modern
+engines. The head of the piston-rod is fitted into a transverse bar,
+or cross-head, which carries properly-shaped pieces at its
+extremities, to which are bolted "gibs," so made as to fit upon guides
+secured to the engine-frame. These guides are adjusted to precise
+parallelism with the centre line of the cylinder. The cross-head,
+sliding in or on these guides, moves in a perfectly straight line,
+and, compelling the piston-rod to move with it, the latter is even
+more perfectly guided than by a parallel-motion. This arrangement,
+where properly proportioned, is not necessarily subject to great
+friction, and is much more easily adjusted and kept in line than the
+parallel-motion when wear occurs or maladjustment takes place.
+
+By the same patent, Watt secured the now common "puppet-valve" with
+beveled seat, and the application of the steam-engine to driving
+rolling-mills and hammers for forges, and to "wheel-carriages for
+removing persons or goods, or other matters, from place to place." For
+the latter purpose he proposes to use boilers "of wood, or of thin
+metal, strongly secured by hoops or otherwise," and containing
+"internal fire-boxes." He proposed to use a condenser cooled by
+currents of air.
+
+It would require too much space to follow Watt in all his schemes for
+the improvement and for the application of the steam-engine. A few of
+the more important and more ingenious only can be described. Many of
+the contracts of Boulton & Watt gave them, as compensation for their
+engines, a fraction--usually one-third--of the value of the fuel saved
+by the use of the Watt engine in place of the engine of Newcomen, the
+amount due being paid annually or semiannually, with an option of
+redemption on the part of the purchaser at ten years' purchase. This
+form of agreement compelled a careful determination, often, of the
+work done and fuel consumed by both the engine taken out and that put
+in its place. It was impossible to rely upon any determination by
+personal observation of the number of strokes made by the engine. Watt
+therefore made a "counter," like that now familiar to every one as
+used on gas-meters. It consists of a train of wheels moving pointers
+on several dials, the first dial showing tens, the second hundreds,
+the third thousands, etc., strokes or revolutions. Motion was
+communicated to the train by means of a pendulum, the whole being
+mounted on the beam of the engine, where every vibration produced a
+swing of the pendulum. Eight dials were sometimes used, the counter
+being set and locked, and only opened once a year, when the time
+arrived for determining the work done during the preceding
+twelve-month.
+
+The application of his engine to purposes for which careful adjustment
+of speed was requisite, or where the load was subject to considerable
+variation, led to the use of a controlling-valve in the steam-pipe,
+called the "throttle-valve," which was adjustable by hand, and
+permitted the supply of steam to the engine to be adjusted at any
+instant and altered to any desired extent. It is now given many forms,
+but it still is most usually made just as originally designed by Watt.
+It consists of a circular disk, which just closes up the steam-pipe
+when set directly across it, or of an elliptical disk, which closes
+the pipe when standing at an angle of somewhat less than 90 deg. with the
+line of the pipe. This disk is carried on a spindle extending through
+the pipe at one side, and carrying on its outer end an arm by means
+of which it may be turned into any position. When placed with its face
+in line with the pipe, it offers very little resistance to the flow of
+steam to the engine. When set in the other position, it shuts off
+steam entirely and stops the engine. It is placed in such position at
+any time, that the speed of the engine is just that required at the
+time. In the engraving of the double-acting engine with fly-wheel
+(Fig. 31), it is shown at _T_, as controlled by the governor.
+
+[Illustration: FIG. 29.--The Governor.]
+
+The governor, or "fly-ball governor," as it is often distinctively
+called, was another of Watt's minor but very essential inventions. Two
+heavy iron or brass balls, _B B'_, were suspended from pins, _C C'_,
+in a little cross-piece carried on the head of a vertical spindle, _A
+A'_, driven by the engine. The speed of the engine varying, that of
+the spindle changed correspondingly, and the faster the balls were
+swung the farther they separated. When the engine's speed decreased,
+the period of revolution of the balls was increased, and they fell
+back toward the spindle. Whenever the velocity of the engine was
+uniform, the balls preserved their distance from the spindle and
+remained at the same height, their altitude being determined by the
+relation existing between the force of gravity and centrifugal force
+in the temporary position of equilibrium. The distance from the point
+of suspension down to the level of the balls is always equal to 9.78
+inches divided by the square of the number of revolutions per
+second--i. e., _h_ = 9.78 (1/_N_^2) = 0.248 (1/_N_^2) meters.
+
+The arms carrying the balls, or the balls themselves, are pinned to
+rods, _M M'_, which are connected to a piece, _N N'_, sliding loosely
+on the spindle. A score, _T_, cut in this piece engages a lever, _V_,
+and, as the balls rise and fall, a rod, _W_, is moved, closing and
+opening the throttle-valve, and thus adjusting the supply of steam in
+such a way as to preserve a nearly fixed speed of engine. The
+connection with the throttle-valve and with the cut-off valve-gear is
+seen not only in the engraving of the double-acting Watt engine, but
+also in those of the Greene and the Corliss engines. This contrivance
+had previously been used in regulating water-wheels and windmills.
+Watt's invention consisted in its application to the regulation of the
+steam-engine.
+
+Still another useful invention of Watt's was his "mercury
+steam-gauge"--a barometer in which the height of the mercury was
+determined by the pressure of the steam instead of that of the
+atmosphere. This simple instrument consisted merely of a bent tube
+containing a portion of mercury. One leg, _B D_, of this U-tube was
+connected with the steam-pipe, or with the boiler by a small
+steam-pipe; the other end, _C_, was open to the atmosphere. The
+pressure of the steam on the mercury in _B D_ caused it to rise in the
+other "leg" to a height exactly proportioned to the pressure, and
+causing very nearly two inches difference of level to the pound, or
+one inch to the pound actual rise in the outer leg. The rude sketch
+from Farey, here given (Fig. 30), indicates sufficiently well the form
+of this gauge. It is still considered by engineers the most reliable
+of all forms of steam-gauge. Unfortunately, it is not conveniently
+applicable at high pressure. The scale, _A_, is marked with numbers
+indicating the pressure, which numbers are indicated by the head of a
+rod floating up with the mercury.
+
+A similar gauge was used to determine the degree of perfection of
+vacuum attained in the condenser, the mercury falling in the outer leg
+as the vacuum became more complete. A perfect vacuum would cause a
+depression of level in that leg to 30 inches below the level of the
+mercury in the leg connected with the condenser. In a more usual form,
+it consisted of a simple glass tube having its lower end immersed in a
+cistern of mercury, as in the ordinary barometer, the top of the tube
+being connected with a pipe leading to the condenser. With a perfect
+vacuum in the condenser, the mercury would rise in the tube very
+nearly 30 inches. Ordinarily, the vacuum is not nearly perfect, and, a
+back pressure remaining in the condenser of one or two pounds per
+square inch, the atmospheric pressure remaining unbalanced is only
+sufficient to raise the mercury 26 or 28 inches above the level of the
+liquid metal in the cistern.
+
+[Illustration: FIG. 30. Mercury Steam Gauge. Glass Water Gauge.]
+
+To determine the height of water in his boiler, Watt added to the
+gauge-cocks already long in use the "glass water-gauge," which is
+still seen in nearly every well-arranged boiler. This was a glass
+tube, _a a'_ (Fig. 30), mounted on a standard attached to the front of
+the boiler, and at such a height that its middle point was very little
+below the proposed water-level. It was connected by a small pipe, _r_,
+at the top to the steam-space, and another little pipe, _r'_, led into
+the boiler from its lower end below the water-line. As the water rose
+and fell within the boiler, its level changed correspondingly in the
+glass. This little instrument is especially liked, because the
+position of the water is at all times shown to the eye of the
+attendant. If carefully protected against sudden changes of
+temperature, it answers perfectly well with even very high pressures.
+
+The engines built by Boulton & Watt were finally fitted with the crank
+and fly-wheel for application to the driving of mills and machinery.
+The accompanying engraving (Fig. 31) shows the engine as thus made,
+combining all of the essential improvements designed by its inventor.
+
+In the engraving, _C_ is the steam-cylinder, _P_ the piston, connected
+to the beam by the link, _g_, and guided by the parallel-motion, _g d
+c_. At the opposite end of the beam a connecting-rod, _O_, connects
+with the crank and fly-wheel shaft. _R_ is the rod of the air-pump, by
+means of which the condenser is kept from being flooded by the water
+used for condensation, which water-supply is regulated by an
+"injection-handle," _E_. A pump-rod, _N_, leads down from the beam to
+the cold-water pump, by which water is raised from the well or other
+source to supply the needed injection-water. The air-pump rod also
+serves as a "plug-rod," to work the valves, the pins at _m_ and _R_
+striking the lever, _m_, at either end of the stroke. When the piston
+reaches the top of the cylinder, the lever, _m_, is raised, opening
+the steam-valve, _B_, at the top, and the exhaust-valve, _E_, at the
+bottom, and at the same time closing the exhaust at the top and the
+steam at the bottom. When the entrance of steam at the top and the
+removal of steam-pressure below the piston has driven the piston to
+the bottom, the pin, _R_, strikes the lever, _m_, opening the steam
+and closing the exhaust valve at the bottom, and similarly reversing
+the position of the valves at the top. The position of the valves is
+changed in this manner with every reversal of the motion of the piston
+as the crank "turns over the centre."
+
+[Illustration: FIG. 31.--Boulton & Watt's Double-Acting Engine, 1784.]
+
+The earliest engines of the double-acting kind, and of any
+considerable size, which were built to turn a shaft, were those which
+were set up in the Albion Mills, near Blackfriars' Bridge, London, in
+1786, and destroyed when the mills burned down in 1791. There were a
+pair of these engines (shown in Fig. 27), of 50 horse-power each, and
+geared to drive 20 pairs of stones, making fine flour and meal.
+Previous to the erection of this mill the power in all such
+establishments had been derived from windmills and water-wheels. This
+mill was erected by Boulton & Watt, and capitalists working with
+them, not only to secure the profit anticipated from locating a
+flour-mill in the city of London, but also with a view to exhibiting
+the capacity of the new double-acting "rotating" engine. The plan was
+proposed in 1783, and work was commenced in 1784; but the mill was not
+set in operation until the spring of 1786. The capacity of the mill
+was, in ordinary work, 16,000 bushels of wheat ground into fine flour
+per week. On one occasion, the mill turned out 3,000 bushels in 24
+hours. In the construction of the machinery of the mill, many
+improvements upon the then standard practice were introduced,
+including cast-iron gearing with carefully-formed teeth and iron
+framing. It was here that John Rennie commenced his work, after
+passing through his apprenticeship in Scotland, sending his chief
+assistant, Ewart, to superintend the erection of the milling
+machinery. The mill was a success as a piece of engineering, but a
+serious loss was incurred by the capitalists engaged in the
+enterprise, as it was set on fire a few years afterward and entirely
+destroyed. Boulton and Watt were the principal losers, the former
+losing L6,000, and the latter L3,000.
+
+The valve-gear of this engine, a view of which is given in Fig. 27,
+was quite similar to that used on the Watt pumping-engine. The
+accompanying illustration (Fig. 32) represents this valve-motion as
+attached to the Albion Mills engine.
+
+[Illustration: FIG. 32.--Valve-Gear of the Albion Mills Engine.]
+
+The steam-pipe, _a b d d e_, leads the steam from the boiler to the
+chambers, _b_ and _e_. The exhaust-pipe, _g g_, leads from _h_ and _i_
+to the condenser. In the sketch, the upper steam and the lower exhaust
+valves, _b_ and _f_, are opened, and the steam-valve, _e_, and
+exhaust-valve, _c_, are closed, the piston being near the upper end of
+the cylinder and descending. _l_ represents the plug-frame, which
+carries tappets, 2 and 3, which engage the lever, _s_, at either end
+of its throw, and turn the shaft, _u_, thus opening and closing _c_
+and _e_ simultaneously by means of the connecting-links, 13 and 14. A
+similar pair of tappets on the opposite side of the plug-rod move the
+valves, _b_ and _f_, by means of the rods, 10 and 11, the arm, _r_,
+when struck by those tappets, turning the shaft, _t_, and thus moving
+the arms to which those rods are attached. Counterbalance-weights,
+carried on the ends of the arms, 4 and 15, retain the valves on their
+seats when closed by the action of the tappets. When the piston nearly
+reaches the lower end of the cylinder, the tappet, 1, engages the arm,
+_r_, closing the steam-valve, _b_, and the next instant shutting the
+exhaust-valve, _f_. At the same time, the tappet, 3, by moving the
+arm, _s_, downward, opens the steam-valve, _e_, and the exhaust-valve,
+_c_. Steam now no longer issues from the steam-pipe into the space,
+_c_, and thence into the engine-cylinder (not shown in the sketch);
+but it now enters the engine through the valve, _e_, forcing the
+piston upwards. The exhaust is simultaneously made to occur at the
+upper end, the rejected steam passing from the engine into the space,
+_c_, and thence through _c_ and the pipe, _g_, into the condenser.
+
+This kind of valve-gear was subsequently greatly improved by Murdoch,
+Watt's ingenious and efficient foreman, but it is now entirely
+superseded on engines of this class by the eccentric, and the various
+forms of valve-gear driven by it.
+
+[Illustration: FIG. 33.--Watt's Half-Trunk Engine, 1784.]
+
+The "trunk-engine" was still another of the almost innumerable
+inventions of Watt. A half-trunk engine is described in his patent of
+1784, as shown in the accompanying sketch (Fig. 33), in which _A_ is
+the cylinder, _B_ the piston, and _C_ its rod, encased in the
+half-trunk, _D_. The plug-rod, _G_, moves the single pair of valves by
+striking the catches, _E_ and _F_, as was usual with Watt's earlier
+engines.
+
+Watt's steam-hammer was patented at the same time. It is seen in Fig.
+34, in which _A_ is the steam-cylinder and _B_ its rod, the engine
+being evidently of the form just described. It works a beam, _C C_,
+which in turn, by the rod, _M_, works the hammer-helve, _L J_, and the
+hammer, _L_. The beam, _F G_, is a spring, and the block, _N_, the
+anvil.
+
+[Illustration: FIG. 34.--The Watt Hammer, 1784.]
+
+Watt found it impossible to determine the duty of his engines at all
+times by measurement of the work itself, and endeavored to find a way
+of ascertaining the power produced, by ascertaining the pressure of
+steam within the cylinder. This pressure was so variable, and subject
+to such rapid as well as extreme fluctuations, that he found it
+impossible to make use of the steam-gauge constructed for use on the
+boiler. He was thus driven to invent a special instrument for this
+work, which he called the "steam-engine indicator." This consisted of
+a little steam-cylinder containing a nicely-fitting piston, which
+moved without noticeable friction through a range which was limited by
+the compression of a helical spring, by means of which the piston was
+secured to the top of its cylinder. The distance through which the
+piston rose was proportional to the pressure exerted upon it, and a
+pointer attached to its rod traversed a scale upon which the pressure
+per square inch could be read. The lower end of the instrument being
+connected with the steam-cylinder of the engine by a small pipe
+fitted with a cock, the opening of the latter permitted steam from the
+engine-cylinder to fill the indicator-cylinder, and the pressure of
+steam was always the same in both cylinders. The indicator-pointer
+therefore traversed the pressure-scale, always exhibiting the pressure
+existing at the instant in the cylinder of the engine. When the engine
+was at rest and steam off, the indicator-piston stood at the same
+level as when detached from the engine, and the pointer stood at 0 on
+the scale. When steam entered, the piston rose and fell with the
+fluctuations of pressure; and when the exhaust-valve opened,
+discharging the steam and producing a vacuum in the steam-cylinder,
+the pointer of the indicator dropped below 0, showing the degree of
+exhaustion. Mr. Southern, one of Watt's assistants, fitted the
+instrument with a sliding board, moved horizontally backward and
+forward by a cord or link-work connecting directly or indirectly with
+the engine-beam, and thus giving it a motion coincident with that of
+the piston. This board carried a piece of paper, upon which a pencil
+attached to the indicator piston-rod drew a curve. The vertical height
+of any point on this curve above the base-line measured the pressure
+in the cylinder at the moment when it was made, and the horizontal
+distance of the point from either end of the diagram determined the
+position, at the same moment, of the engine-piston. The curve thus
+inscribed, called the "indicator card," or indicator diagram,
+exhibiting every minute change in the pressure of steam in the engine,
+not only enabled the mean pressure and the power of the engine to be
+determined by its measurement, but, to the eye of the expert engineer,
+it was a perfectly legible statement of the position of the valves of
+the engine, and revealed almost every defect in the action of the
+engine which could not readily be detected by external examination. It
+has justly been called the "engineers' stethoscope," opening the
+otherwise inaccessible parts of the steam-engine to the inspection of
+the engineer even more satisfactorily than the stethoscope of the
+physician gives him a knowledge of the condition and working of organs
+contained within the human body. This indispensable and now familiar
+engineers' instrument has since been modified and greatly improved in
+detail.
+
+The Watt engine had, by the construction of the improvements described
+in the patents of 1782-'85, been given its distinctive form, and the
+great inventor subsequently did little more than improve it by
+altering the forms and proportions of its details. As thus practically
+completed, it embodied nearly all the essential features of the modern
+engine; and, as we have seen, the marked features of our latest
+practice--the use of the double cylinder for expansion, the cut-off
+valve-gear, and surface-condensation--had all been proposed, and to a
+limited extent introduced. The growth of the steam-engine has here
+ceased to be rapid, and the changes which followed the completion of
+the work of James Watt have been minor improvements, and rarely, if
+ever, real developments.
+
+Watt's mind lost none of its activity, however, for many years. He
+devised and patented a "smoke-consuming furnace," in which he led the
+gases produced on the introduction of fresh fuel over the already
+incandescent coal, and thus burned them completely. He used two fires,
+which were coaled alternately. Even when busiest, also, he found time
+to pursue more purely scientific studies. With Boulton, he induced a
+number of well-known scientific men living near Birmingham to join in
+the formation of a "Lunar Society," to meet monthly at the houses of
+its members, "at the full of the moon." The time was thus fixed in
+order that those members who came from a distance should be able to
+drive home, after the meetings, by moonlight. Many such societies were
+then in existence in England; but that at Birmingham was one of the
+largest and most distinguished of them all. Boulton, Watt, Drs. Small,
+Darwin, and Priestley, were the leaders, and among their occasional
+visitors were Herschel, Smeaton, and Banks. Watt called these meetings
+"Philosophers' meetings." It was during the period of most active
+discussion at the "philosophers' meetings" that Cavendish and
+Priestley were experimenting with mixtures of oxygen and hydrogen, to
+determine the nature of their combustion. Watt took much interest in
+the subject, and, when informed by Priestley that he and Cavendish had
+both noticed a deposit of moisture invariably succeeding the explosion
+of the mixed gases, when contained in a cold vessel, and that the
+weight of this water was approximately equal to the weight of the
+mixed gases, he at once came to the conclusion that the union of
+hydrogen with oxygen produced water, the latter being a chemical
+compound, of which the former were constituents. He communicated this
+reasoning, and the conclusions to which it had led him, to Boulton, in
+a letter written in December, 1782, and addressed a letter some time
+afterward to Priestley, which was to have been read before the Royal
+Society in April, 1783. The letter was not read, however, until a year
+later, and, three months after, a paper by Cavendish, making the same
+announcement, had been laid before the Society. Watt stated that both
+Cavendish and Lavoisier, to whom also the discovery is ascribed,
+received the idea from him.
+
+The action of chlorine in bleaching organic coloring-matters, by (as
+since shown) decomposing them and combining with their hydrogen, was
+made known to Watt by M. Berthollet, the distinguished French chemist,
+and the former immediately introduced its use into Great Britain, by
+inducing his father-in-law, Mr. Macgregor, to make a trial of it.
+
+The copartnership of Boulton & Watt terminated by limitation, and with
+the expiration of the patents under which they had been working, in
+the first year of the present century; and both partners, now old and
+feeble, withdrew from active business, leaving their sons to renew the
+agreement and to carry on the business under the same firm-style.
+
+Boulton, however, still interested himself in some branches of
+manufacture, especially in his mint, where he had coined many years
+and for several nations.
+
+Watt retired, a little later, to Heathfield, where he passed the
+remainder of his life in peaceful enjoyment of the society of his
+friends, in studies of all current matters of interest in science, as
+well as in engineering. One by one his old friends died--Black in
+1799, Priestley, an exile to America, in 1803, and Robison a little
+later. Boulton died, at the age of eighty-one, August 17, 1809, and
+even the loss of this nearest and dearest of his friends outside the
+family was a less severe blow than that of his son Gregory, who died
+in 1804.
+
+Yet the great engineer and inventor was not depressed by the
+loneliness which was gradually coming upon him. He wrote: "I know that
+all men must die, and I submit to the decrees of Nature, I hope, with
+due reverence to the Disposer of events;" and neglected no opportunity
+to secure amusement or instruction, and kept body and mind constantly
+occupied. He still attended the weekly meetings of the club, meeting
+Rennie and Telford, and other distinguished men of his own and the
+succeeding generation. He lost nothing of his fondness for invention,
+and spent many months in devising a machine for copying statuary,
+which he had not perfected to his own satisfaction at the time of his
+death, ten years later. This machine was a kind of pentagraph, which
+could be worked in any plane, and in which the marking-pencil gave
+place to a cutting-tool. The tracing-point followed the surface of the
+pattern, while the cutting-point, following its motion precisely,
+formed a fac-simile in the material operated upon.
+
+In the year 1800 he invented the water-main which was laid down by the
+Glasgow Water-Works Company across the Clyde. The joints were
+spherical and articulated, like those of the lobster's tail.
+
+His workshop, of which a sketch is hereafter given, as drawn by the
+artist Skelton, was in the garret of his house, and was well supplied
+with tools and all kinds of laboratory material. His lathe and his
+copying-machine were placed before the window, and his writing-desk in
+the corner. Here he spent the greater part of his leisure time, often
+even taking his meals in the little shop, rather than go to the table
+for them. Even when very old, he occasionally made a journey to London
+or Glasgow, calling on his old friends and studying the latest
+engineering devices and inspecting public works, and was everywhere
+welcomed by young and old as the greatest living engineer, or as the
+kind and wise friend of earlier days.
+
+He died August 19, 1819, in the eighty-third year of his age, and was
+buried in Handsworth Church. The sculptor Chantrey was employed to
+place a fitting monument above his grave, and the nation erected a
+statue of the great man in Westminster Abbey.
+
+This sketch of the greatest of all the inventors of the steam-engine
+has been given no greater length than its subject justifies. Whether
+we consider Watt as the inventor of the standard steam-engine of the
+nineteenth century, as the scientific investigator of the physical
+principles upon which the invention is based, or as the builder and
+introducer of the most powerful known instrument by which the "great
+sources of power in Nature are converted, adapted, and applied for the
+use and convenience of man," he is fully entitled to preeminence. His
+character as a man was no less admirable than as an engineer.
+
+Smiles, Watt's most conscientious and indefatigable biographer,
+writes:[41]
+
+  [41] "Life of Watt," p. 512.
+
+[Illustration: FIG. 35.--James Watt's Workshop. (From Smiles's "Lives
+of Boulton and Watt.")]
+
+"Some months since, we visited the little garret at Heathfield in
+which Watt pursued the investigations of his later years. The room had
+been carefully locked up since his death, and had only once been swept
+out. Everything lay very much as he left it. The piece of iron which
+he was last employed in turning, lay on the lathe. The ashes of the
+last fire were in the grate; the last bit of coal was in the scuttle.
+The Dutch oven was in its place over the stove, and the frying-pan in
+which he cooked his meals was hanging on its accustomed nail. Many
+objects lay about or in the drawers, indicating the pursuits which had
+been interrupted by death--busts, medallions, and figures, waiting to
+be copied by the copying-machine--many medallion-moulds, a store of
+plaster-of-Paris, and a box of plaster casts from London, the contents
+of which do not seem to have been disturbed. Here are Watt's ladles
+for melting lead, his foot-rule, his glue-pot, his hammer. Reflecting
+mirrors, an extemporized camera with the lenses mounted on pasteboard,
+and many camera-glasses laid about, indicate interrupted experiments
+in optics. There are quadrant-glasses, compasses, scales, weights, and
+sundry boxes of mathematical instruments, once doubtless highly
+prized. In one place a model of the governor, in another of the
+parallel-motion, and in a little box, fitted with wooden cylinders
+mounted with paper and covered with figures, is what we suppose to be
+a model of his calculating-machine. On the shelves are minerals and
+chemicals in pots and jars, on which the dust of nearly half a century
+has settled. The moist substances have long since dried up; the putty
+has been turned to stone, and the paste to dust. On one shelf we come
+upon a dish in which lies a withered bunch of grapes. On the floor, in
+a corner, near to where Watt sat and worked, is a hair-trunk--a
+touching memorial of a long-past love and a long-dead sorrow. It
+contains all poor Gregory's school-books, his first attempts at
+writing, his boy's drawings of battles, his first school-exercises
+down to his college-themes, his delectuses, his grammars, his
+dictionaries, and his class-books--brought into this retired room,
+where the father's eye could rest upon them. Near at hand is the
+sculpture-machine, on which he continued working to the last. Its
+wooden frame is worm-eaten, and dropping into dust, like the hands
+that made it. But though the great workman is gone to rest, with all
+his griefs and cares, and his handiwork is fast crumbling to decay,
+the spirit of his work, the thought which he put into his inventions,
+still survives, and will probably continue to influence the destinies
+of his race for all time to come."
+
+The visitor to Westminster Abbey will find neither monarch, nor
+warrior, nor statesman, nor poet, honored with a nobler epitaph than
+that which is inscribed on the pedestal of Chantrey's monument to
+Watt:
+
+                      NOT TO PERPETUATE A NAME,
+          WHICH MUST ENDURE WHILE THE PEACEFUL ARTS FLOURISH,
+                              BUT TO SHOW
+    THAT MANKIND HAVE LEARNT TO HONOR THOSE WHO BEST DESERVE THEIR
+                              GRATITUDE,
+                              THE KING,
+   HIS MINISTERS, AND MANY OF THE NOBLES AND COMMONERS OF THE REALM,
+                        RAISED THIS MONUMENT TO
+                              JAMES WATT,
+            WHO, DIRECTING THE FORCE OF AN ORIGINAL GENIUS,
+               EARLY EXERCISED IN PHILOSOPHIC RESEARCH,
+                         TO THE IMPROVEMENT OF
+                           THE STEAM-ENGINE,
+  ENLARGED THE RESOURCES OF HIS COUNTRY, INCREASED THE POWER OF MAN,
+                     AND ROSE TO AN EMINENT PLACE
+     AMONG THE MOST ILLUSTRIOUS FOLLOWERS OF SCIENCE AND THE REAL
+                       BENEFACTORS OF THE WORLD.
+
+                      BORN AT GREENOCK, MDCCXXXVI.
+
+            DIED AT HEATHFIELD, IN STAFFORDSHIRE, MDCCCXIX.
+
+[Illustration: Tomb of James Watt.]
+
+
+SECTION II.--THE CONTEMPORARIES OF JAMES WATT.
+
+In the chronology of the steam-engine, the contemporaries of Watt have
+been so completely overshadowed by the greater and more successful
+inventor, as to have been almost forgotten by the biographer and by
+the student of history. Yet, among the engineers and engine-builders,
+as well as among the inventors of his day, Watt found many
+enterprising rivals and keen competitors. Some of these men, had they
+not been so completely fettered by Watt's patents, would have probably
+done work which would have entitled them to far higher honor than has
+been accorded them.
+
+WILLIAM MURDOCH was one of the men to whom Watt, no less than the
+world, was greatly indebted. For many years he was the assistant,
+friend, and coadjutor of Watt; and it is to his ingenuity that we are
+to give credit for not only many independent inventions, but also for
+the suggestions and improvements which were often indispensable to the
+formation and perfection of some of Watt's own inventions.
+
+Murdoch was employed by Boulton & Watt in 1776, and was made
+superintendent of construction in the engine department, and given
+general charge of the erection of engines. He was sent into Cornwall,
+and spent in that district much of the time during which he served the
+firm, erecting pumping-engines, the construction of which for so many
+years constituted a large part of the business of the Soho
+establishment. He was looked upon by both Boulton and Watt as a
+sincere friend, as well as a loyal adherent, and from 1810 to 1830 was
+given a partner's share of the income of the firm, and a salary of
+L1,000. He retired from business at the last of the two dates named,
+and, dying in 1839, was buried near the two partners in Handsworth
+Church.
+
+Murdoch made a model, in 1784, of the locomotive patented by Watt in
+that year. He devised the arrangement of "sun-and-planet wheels,"
+adopted for a time in all of Watt's "rotative" engines, and invented
+the oscillating steam-engine (Fig. 36) in 1785, using the "D-slide
+valves," _G_, moved by the gear, _E_, which was driven by an eccentric
+on the shaft, without regard to the oscillation of the cylinder, _A_.
+He was the inventor of a rotary engine and of many minor machines for
+special purposes, and of many machine-tools used at Soho in building
+engines and machines. He seems, like Watt, to have had special
+fondness for the worm-gear, and introduced it wherever it could
+properly take the place of ordinary gearing. Some of the machines
+designed by Watt and Murdoch, who always worked well together, were
+found still in use and in good working condition by the author when
+visiting the works at Soho in 1873. The old mint in which, from 1797
+to 1805, Boulton had coined 4,000 tons of copper, had then been pulled
+down, and a new mint had been erected in 1860. Many old machines
+still remained about the establishment as souvenirs of the three great
+mechanics.
+
+[Illustration: FIG. 36.--Murdoch's Oscillating Engine, 1785.]
+
+Outside of Soho, Murdoch also found ample employment for his inventive
+talent. In 1792, while at Redruth, his residence before finally
+returning to Soho, he was led to speculate upon the possibility of
+utilizing the illuminating qualities of coal-gas, and, convinced of
+its practicability, he laid the subject before the Royal Society in
+1808, and was awarded the Rumford gold medal. He had, ten years
+earlier, lighted a part of the Soho works with coal-gas, and in 1803
+Watt authorized him to extend his pipes throughout all the buildings.
+Several manufacturers promptly introduced the new light, and its use
+extended very rapidly.
+
+Still another of Murdoch's favorite schemes was the transmission of
+power by the use of compressed air. He drove the pattern-shop engine
+at Soho by means of air from the blowing-engine in the foundery, and
+erected a pneumatic lift to elevate castings from the foundery-floor
+to the canal-bank. He made a steam-gun, introduced the heating of
+buildings by the circulation of hot water, and invented the method of
+transmitting packages through tubes by the impulse of compressed air,
+as now practised by the "pneumatic dispatch" companies. He died at the
+age of eighty-five years.
+
+Among the most active and formidable of Watt's business rivals was
+JONATHAN HORNBLOWER, the patentee of the "compound" or double-cylinder
+engine. A sketch of this engine, as patented by Hornblower in 1781, is
+here given (Fig. 37). It was first described by the inventor in the
+"Encyclopaedia Britannica." It consists, as is seen by reference to the
+engraving, of two steam-cylinders, _A_ and _B_--_A_ being the low and
+_B_ the high pressure cylinder--the steam leaving the latter being
+exhausted into the former, and, after doing its work there, passing
+into the condenser, as already described. The piston-rods, _C_ and
+_D_, are both connected to the same part of the beam by chains, as in
+the other early engines. These rods pass through stuffing-boxes in the
+cylinder-heads, which are fitted up like those seen on the Watt
+engine. Steam is led to the engine through the pipe, _G Y_, and cocks,
+_a_, _b_, _c_, and _d_, are adjustable, as required, to lead steam
+into and from the cylinders, and are moved by the plug-rod, _W_, which
+actuates handles not shown. _K_ is the exhaust-pipe leading to the
+condenser. _V_ is the engine feed-pump rod, and _X_ the great rod
+carrying the pump-buckets at the bottom of the shaft.
+
+The cocks _c_ and _a_ being open and _b_ and _d_ shut, the steam
+passes from the boiler into the upper part of the steam-cylinder, _B_;
+and the communication between the lower part of _B_ and the top of _A_
+is also open. Before starting, steam being shut off from the engine,
+the great weight of the pump-rod, _X_, causes that end of the beam to
+preponderate, the pistons standing, as shown, at the top of their
+respective steam-cylinders.
+
+The engine being freed from all air by opening all the valves and
+permitting the steam to drive it through the engine and out of the
+condenser through the "snifting-valve," _O_, the valves _b_ and _d_
+are closed, and the cock in the exhaust-pipe opened.
+
+[Illustration: FIG. 37.--Hornblower's Compound Engine, 1781.]
+
+The steam beneath the piston of the large cylinder is immediately
+condensed, and the pressure on the upper side of that piston causes it
+to descend, carrying that end of the beam with it, and raising the
+opposite end with the pump-rods and their attachments. At the same
+time, the steam from the lower end of the small high-pressure cylinder
+being let into the upper end of the larger cylinder, the completion of
+the stroke finds a cylinder full of steam transferred from the one to
+the other with corresponding increase of volume and decrease of
+pressure. While expanding and diminishing in pressure as it passes
+from the smaller into the larger cylinder, this charge of steam
+gradually resists less and less the pressure of the steam from the
+boiler on the upper side of the piston of the small cylinder, _B_, and
+the net result is the movement of the engine by pressures exerted on
+the upper sides of both pistons and against pressures of less
+intensity on the under sides of both. The pressures in the lower part
+of the small cylinder, in the upper part of the large cylinder, and in
+the communicating passage, are evidently all equal at any given time.
+
+When the pistons have reached the bottoms of their respective
+cylinders, the valves at the top of the small cylinder, _B_, and at
+the bottom of the large cylinder, _A_, are closed, and the valves _c_
+and _d_ are opened. Steam from the boiler now enters beneath the
+piston of the small cylinder; the steam in the larger cylinder is
+exhausted into the condenser, and the steam already in the small
+cylinder passes over into the large cylinder, following up the piston
+as it rises.
+
+Thus, at each stroke a small cylinder full of steam is taken from the
+boiler, and the same weight, occupying the volume of the larger
+cylinder, is exhausted into the condenser from the latter cylinder.
+
+Referring to the method of operation of this engine, Prof. Robison
+demonstrated that the effect produced was the same as in Watt's
+single-cylinder engine--a fact which is comprehended in the law
+enunciated many years later by Rankine, that, "so far as the
+theoretical action of the steam on the piston is concerned, it is
+immaterial whether the expansion takes place in one cylinder, or in
+two or more cylinders." It was found, in practice, that the Hornblower
+engine was no more economical than the Watt engine; and that erected
+at the Tin Croft Mine, Cornwall, in 1792, did even less work with the
+same fuel than the Watt engines.
+
+Hornblower was prosecuted by Boulton & Watt for infringement. The suit
+was decided against him, and he was imprisoned in default of payment
+of the royalty, and fine demanded. He died a disappointed and
+impoverished man. The plan thus unsuccessfully introduced by
+Hornblower was subsequently modified and adopted by others among the
+contemporaries of Watt; and, with higher steam and the use of the Watt
+condenser, the "compound" gradually became a standard type of
+steam-engine.
+
+Arthur Woolf, in 1804, re-introduced the Hornblower or Falck engine,
+with its two steam-cylinders, using steam of higher tension. His first
+engine was built for a brewery in London, and a considerable number
+were subsequently made. Woolf expanded his steam from six to nine
+times, and the pumping-engines built from his plans were said to have
+raised about 40,000,000 pounds one foot high per bushel of coals, when
+the Watt engine was raising but little more than 30,000,000. In one
+case, a duty of 57,000,000 was claimed.
+
+The most successful of those competitors of Watt who endeavored to
+devise a peculiar form of pumping-engine, which should have the
+efficiency of that of Boulton & Watt, and the necessary advantage in
+first cost, were WILLIAM BULL and RICHARD TREVITHICK.[42] The
+accompanying illustration shows the design, which was then known as
+the "Bull Cornish Engine."
+
+  [42] For an exceedingly interesting and very faithful account of
+  their work, _see_ "Life of Richard Trevithick," by F. Trevithick,
+  London, 1872.
+
+[Illustration: FIG. 88.--Bull's Pumping-Engine, 1798.]
+
+The steam-cylinder, _a_, is carried on wooden beams, _b_, extending
+across the engine-house directly over the pump-well. The piston-rod,
+_c_, is secured to the pump-rods, _d d_, the cylinder being inverted,
+and the pumps, _e_, in the shaft, _f_, are thus operated without the
+intervention of the beam invariably seen in Watt's engines. A
+connecting-rod, _g_, attached to the pump-rod and to the end of a
+balance-beam, _h_, operates the latter, and is counterbalanced by a
+weight, _i_. The rod, _j_, serves both as a plug-rod and as an
+air-pump connecting-rod. A snifting-valve, _k_, opens when the engine
+is blown through, and relieves the condenser and air-pump, _l_, of all
+air. The rod, _m_, operates a solid air-pump piston, the valves of the
+pump being placed on either side at the base, instead of in the
+pump-bucket, as in Watt's engines. The condensing-water cistern was a
+wooden tank, _n_. A jet "pipe-condenser," _o_, was used instead of a
+jet condenser of the form adopted by other makers, and was supplied
+with water through the cock, _p_. The plug-rod, _q_, as it rises and
+falls with the pump-rods and balance-beam, operates the
+"gear-handles," _r r_, and opens and closes the valves, _s s_, at the
+required points in the stroke. The attendant works these valves by
+hand, in starting, from the floor, _t_. The operation of the engine is
+similar to that of a Watt engine. It is still in use, with a few
+modifications and improvements, and is a very economical and durable
+machine. It has not been as generally adopted, however, as it would
+probably have been had not the legal proscription of Watt's patents so
+seriously interfered with its introduction. Its simplicity and
+lightness are decided advantages, and its designers are entitled to
+great credit for their boldness and ingenuity, as displayed in their
+application of the minor devices which distinguish the engine. The
+design is probably to be credited to Bull originally; but Trevithick
+built some of these engines, and is supposed to have greatly improved
+them while working with Edward Bull, the son of the inventor, William
+Bull. One of these engines was erected by them at the Herland Mine,
+Cornwall, in 1798, which had a steam-cylinder 60 inches in diameter,
+and was built on the plan just described.
+
+Another of the contemporaries of James Watt was a clergyman, EDWARD
+CARTWRIGHT, the distinguished inventor of the power-loom, and of the
+first machine ever used in combing wool, who revived Watt's plan of
+surface-condensation in a somewhat modified form. Watt had made a
+"pipe-condenser," similar in plan to those now often used, but
+had simply immersed it in a tank of water, instead of in a
+constantly-flowing stream. Cartwright proposed to use two concentric
+cylinders or spheres, between which the steam entered when exhausted
+from the cylinder of the engine, and was condensed by contact with
+the metal surfaces. Cold water within the smaller and surrounding the
+exterior vessel kept the metal cold, and absorbed the heat discharged
+by the condensing vapor.
+
+Cartwright's engine is best described in the _Philosophical Magazine_
+of June, 1798, from which the accompanying sketch is copied.
+
+[Illustration: FIG. 39.--Cartwright's Engine, 1798.]
+
+The object of the inventor is stated to have been to remedy the
+defects of the Watt engine--imperfect vacuum, friction, and
+complication.
+
+In the figure, the steam-cylinder takes steam through the pipe, _B_.
+The piston, _R_, has a rod extending downward to the smaller
+pump-piston, _G_, and upward to the cross-head, which, in turn, drives
+the cranks above, by means of connecting-rods. The shafts thus turned
+are connected by a pair of gears, _M L_, of which one drives a pinion
+on the shaft of the fly-wheel. _D_ is the exhaust-pipe leading to the
+condenser, _F_; and the pump, _G_, removes the air and water of
+condensation, forcing it into the hot-well, _H_, whence it is returned
+to the boiler through the pipe, _I_. A float in _H_ adjusts an
+air-valve, so as to keep a supply of air in the chamber, to serve as a
+cushion and to make an air-chamber of the reservoir, and permits the
+excess to escape. The large tank contains the water supplied for
+condensing the steam.
+
+The piston, _R_, is made of metal, and is packed with two sets of cut
+metal rings, forced out against the sides of the cylinder by steel
+springs, the rings being cut at three points in the circumference, and
+kept in place by the springs. The arrangement of the two cranks, with
+their shafts and gears, is intended to supersede Watt's plan for
+securing a perfectly rectilinear movement of the head of the
+piston-rod, without friction.
+
+In the accounts given of this engine, great stress is laid upon the
+supposed important advantage here offered, by the introduction of the
+surface-condenser, of permitting the employment of a working-fluid
+other than steam--as, for example, alcohol, which is too valuable to
+be lost. It was proposed to use the engine in connection with a still,
+and thus to effect great economy by making the fuel do double duty.
+The only part of the plan which proved both novel and valuable was the
+metallic packing and piston, which has not yet been superseded. The
+engine itself never came into use.
+
+At this point, the history of the steam-engine becomes the story of
+its applications in several different directions, the most important
+of which are the raising of water--which had hitherto been its only
+application--the locomotive-engine, the driving of mill-machinery, and
+steam-navigation.
+
+Here we take leave of James Watt and of his contemporaries, of the
+former of whom a French author[43] says: "The part which he played in
+the mechanical applications of the power of steam can only be compared
+to that of Newton in astronomy and of Shakespeare in poetry." Since
+the time of Watt, improvements have been made principally in matters
+of mere detail, and in the extension of the range of application of
+the steam-engine.
+
+  [43] Bataille. "Traite des Machines a Vapeur," Paris, 1847.
+
+[Illustration]
+
+
+
+
+CHAPTER IV.
+
+_THE MODERN STEAM-ENGINE._
+
+  "Those projects which abridge distance have done most for the
+  civilization and happiness of our species."--MACAULAY.
+
+THE SECOND PERIOD OF APPLICATION--1800-'40.
+
+STEAM-LOCOMOTION ON RAILROADS.
+
+
+[Illustration: FIG. 40.--The First Railroad-Car, 1825.]
+
+Introductory.--The commencement of the nineteenth century found the
+modern steam-engine fully developed in all its principal features, and
+fairly at work in many departments of industry. The genius of
+Worcester, and Morland, and Savery, and Desaguliers, had, in the first
+period of the application of the power of steam to useful work,
+effected a beginning which, looked upon from a point of view which
+exhibits its importance as the first step toward the wonderful results
+to-day familiar to every one, appears in its true light, and entitles
+those great men to even greater honor than has been accorded them. The
+results actually accomplished, however, were absolutely insignificant
+in comparison with those which marked the period of development just
+described. Yet even the work of Watt and of his contemporaries was but
+a mere prelude to the marvellous advances made in the succeeding
+period, to which we are now come, and, in extent and importance, was
+insignificant in comparison with that accomplished by their successors
+in the development of all mechanical industries by the application of
+the steam-engine to the movement of every kind of machine.
+
+The first of the two periods of application saw the steam-engine
+adapted simply to the elevation of water and the drainage of mines;
+during the second period it was adapted to every variety of useful
+work, and introduced wherever the muscular strength of men and
+animals, or the power of wind and of falling water, which had
+previously been the only motors, had found application. A history of
+the development of industries by the introduction of steam-power
+during this period, would be no less extended and hardly less
+interesting than that of the steam-engine itself.
+
+The way had been fairly opened by Boulton and Watt; and the year 1800
+saw a crowd of engineers and manufacturers entering upon it, eager to
+reap the harvest of distinction and of pecuniary returns which seemed
+so promising to all. The last year of the eighteenth century was also
+the last of the twenty-five years of partnership of Boulton & Watt,
+and, with it, the patents under which that firm had held the great
+monopoly of steam-engine building expired. The right to manufacture
+the modern steam-engine was common to all. Watt had, at the
+commencement of the new century, retired from active business-life.
+Boulton remained in business; but he was not the inventor of the new
+engine, and could not retain, by the exercise of all his remaining
+power, the privileges previously held by legal authorization.
+
+The young Boulton and the young Watt were not the Boulton & Watt of
+earlier years; and, had they possessed all of the business talent and
+all of the inventive genius of their fathers, they could not have
+retained control of a business which was now growing far more rapidly
+than the facilities for manufacturing could be extended in any single
+establishment. All over the country, and even on the Continent of
+Europe, and in America, thousands of mechanics, and many men of
+mechanical tastes in other professions, were familiar with the
+principles of the new machine, and were speculating upon its value for
+all the purposes to which it has since been applied; and a multitude
+of enthusiastic mechanics, and a larger multitude of visionary and
+ignorant schemers, were experimenting with every imaginable device, in
+the vain hope of attaining perpetual motion, and other hardly less
+absurd results, by its modification and improvement. Steam-engine
+building establishments sprang up wherever a mechanic had succeeded in
+erecting a workshop and in acquiring a local reputation as a worker in
+metal, and many of Watt's workmen went out from Soho to take charge of
+the work done in these shops. Nearly all of the great establishments
+which are to-day most noted for their extent and for the importance
+and magnitude of the work done in them, not only in Great Britain, but
+in Europe and the United States, came into existence during this
+second period of the application of the steam-engine as a prime mover.
+
+The new establishments usually grew out of older shops of a less
+pretentious character, and were managed by men who had been trained by
+Watt, or who had had a still more awakening experience with those who
+vainly strove to make up, by their ingenuity and by great excellence
+of workmanship, the advantages possessed at Soho in a legal monopoly
+and greater experience in the business.
+
+It was exceedingly difficult to find expert and conscientious workmen,
+and machine-tools had not become as thoroughly perfected as had the
+steam-engine itself. These difficulties were gradually overcome,
+however, and thenceforward the growth of the business was increasingly
+rapid.
+
+Every important form of engine had now been invented. Watt had
+perfected, with the aid of Murdoch, both the pumping-engine and the
+rotative steam-engine for application to mills. He had invented the
+trunk engine, and Murdoch had devised the oscillating engine and the
+ordinary slide-valve, and had made a model locomotive-engine, while
+Hornblower had introduced the compound engine. The application of
+steam to navigation had been often proposed, and had sometimes been
+attempted, with sufficient success to indicate to the intelligent
+observer an ultimate triumph. It only remained to extend the use of
+steam as a motor into all known departments of industry, and to effect
+such improvements in details as experience should prove desirable.
+
+The engines of Hero, of Porta, and of Branca were, it will be
+remembered, non-condensing; but the first plan of a non-condensing
+engine that could be made of any really practical use is given in the
+"Theatrum Machinarum" of Leupold, published in 1720. This sketch is
+copied in Fig. 41. It is stated by Leupold that this plan was
+suggested by Papin. It consists of two single-acting cylinders, _r s_,
+receiving steam alternately from the same steam-pipe through a
+"four-way cock," _x_, and exhausting into the atmosphere. Steam is
+furnished by the boiler, _a_, and the pistons, _c d_, are alternately
+raised and depressed, depressing and raising the pump-rods, _k l_, to
+which they are attached by the beams, _h g_, vibrating on the centres,
+_i i_. The water from the pumps, _o p_, is forced up the stand-pipe,
+_q_, and discharged at its top. The alternate action of the
+steam-pistons is secured by turning the "four-way cock," _x_, first
+into the position shown, and then, at the completion of the stroke,
+into the reverse position, by which change the steam from the boiler
+is then led into the cylinder, _s_, and the steam in _r_ is discharged
+into the atmosphere.[44]
+
+  [44] _Vide_ "Theatrum Machinarum," vol. iii., Tab. 30.
+
+[Illustration: FIG. 41.--Leupold's Engine, 1720.]
+
+Leupold states that he is indebted to Papin for the suggestion of the
+peculiar valve here used. He also proposed to use a Savery engine
+without condensation in raising water. We have no evidence that this
+engine was ever built.
+
+The first rude scheme for applying steam to locomotion on land was
+probably that of Isaac Newton, who, in 1680, proposed the machine
+shown in the accompanying figure (42), which will be recognized as
+representing the scientific toy which is found in nearly every
+collection of illustrative philosophical apparatus. As described in
+the "Explanation of the Newtonian Philosophy," it consists of a
+spherical boiler, _B_, mounted on a carriage. Steam issuing from the
+pipe, _C_, seen pointing directly backward, by its reaction upon the
+carriage, drives the latter ahead. The driver, sitting at _A_,
+controls the steam by the handle, _E_, and cock, _F_. The fire is seen
+at _D_.
+
+[Illustration: FIG. 42.--Newton's Steam-Carriage, 1680.]
+
+When, at the end of the eighteenth century, the steam-engine had been
+so far perfected that the possibility of its successful application to
+locomotion had become fully and very generally recognized, the problem
+of adapting it to locomotion on land was attacked by many inventors.
+
+Dr. Robison had, as far back as in 1759, proposed it to James Watt
+during one of their conferences, at a time when the latter was even
+more ignorant than the former of the principles which were involved in
+the construction of the steam-engine, and this suggestion may have had
+some influence in determining Watt to pursue his research; thus
+setting in operation that train of thoughtful investigation and
+experiment which finally earned for him his splendid fame.
+
+In 1765, that singular genius, Dr. Erasmus Darwin, whose celebrity was
+acquired by speculations in poetry and philosophy as well as in
+medicine, urged Matthew Boulton--subsequently Watt's partner, and just
+then corresponding with our own Franklin in relation to the use of
+steam-power--to construct a steam-carriage, or "fiery chariot," as he
+poetically styled it, and of which he sketched a set of plans. A young
+man named Edgeworth became interested in the scheme, and, in 1768,
+published a paper which had secured for him a gold medal from the
+Society of Arts. In this paper he proposed railroads on which the
+carriages were to be drawn by horses, _or by ropes from steam-winding
+engines_.
+
+[Illustration: FIG. 43.--Read's Steam-Carriage, 1790.]
+
+Nathan Read, of whom an account will be given hereafter, when
+describing his attempt to introduce steam-navigation, planned, and in
+1790 obtained a patent for, a steam-carriage, of which the sketch seen
+in Fig. 43 is copied from the rough drawing accompanying his
+application. In the figure, _A A A A_ are the wheels; _B B_, pinions
+on the hubs of the rear wheels, which are driven by a ratchet
+arrangement on the racks, _G G_, connected with the piston-rods; _C o_
+is the boiler; _D D_, the steam-pipes carrying steam to the
+steam-cylinder, _E E_; _F F_ are the engine-frames; _H_ is the
+"tongue" or "pole" of the carriage, and is turned by a horizontal
+steering-wheel, with which it is connected by the ropes or chains, _I
+K_, _I K_; _W W_ are the cocks, which serve to shut off steam from the
+engine when necessary, and to determine the amount of steam to be
+admitted. The pipes _a a_ are exhaust-pipes, which the inventor
+proposed to turn so that they should point backward, in order to
+secure the advantage of the effort of reaction of the expelled steam.
+(!)
+
+Read made a model steam-carriage, which he exhibited when endeavoring
+to secure assistance in furtherance of his schemes, but seems to have
+given more attention to steam-navigation, and nothing was ever
+accomplished by him in this direction.
+
+These were merely promising schemes, however. The first actual
+experiment was made, as is supposed, by a French army-officer,
+NICHOLAS JOSEPH CUGNOT, who in 1769 built a steam-carriage, which was
+set at work in presence of the French Minister of War, the Duke de
+Choiseul. The funds required by him were furnished by the Compte de
+Saxe. Encouraged by the partial success of the first locomotive, he,
+in 1770, constructed a second (Fig. 44), which is still preserved in
+the Conservatoire des Arts et Metiers, Paris.
+
+[Illustration: FIG. 44.--Cugnot's Steam-Carriage, 1770.]
+
+This machine, when recently examined by the author, was still in an
+excellent state of preservation. The carriage and its machinery are
+substantially built and well-finished, and exceedingly creditable
+pieces of work in every respect. It surprises the engineer to find
+such evidence of the high character of the work of the mechanic
+Brezin a century ago. The steam-cylinders were 13 inches in diameter,
+and the engine was evidently of considerable power. This locomotive
+was intended for the transportation of artillery. It consists of two
+beams of heavy timber extending from end to end, supported by two
+strong wheels behind, and one still heavier but smaller wheel in
+front. The latter carries on its rim blocks which cut into the soil as
+the wheel turns, and thus give greater holding power. The single wheel
+is turned by two single-acting engines, one on each side, supplied
+with steam by a boiler (seen in the sketch) suspended in front of the
+machine. The connection between the engines and the wheels was
+effected by means of pawls, as first proposed by Papin, which could be
+reversed when it was desired to drive the machine backward. A seat is
+mounted on the carriage-body for the driver, who steers the machine by
+a train of gearing, which turns the whole frame, carrying the
+machinery 15 or 20 degrees either way. This locomotive was found to
+have been built on a tolerably satisfactory general plan; but the
+boiler was too small, and the steering apparatus was incapable of
+handling the carriage with promptness.
+
+The death of one of Cugnot's patrons, and the exile of the other, put
+an end to Cugnot's experiments.
+
+Cugnot was a mechanic by choice, and exhibited great talent. He was a
+native of Vaud, in Lorraine, where he was born in 1725. He served both
+in the French and the German armies. While under the Marechal de Saxe,
+he constructed his first steam locomotive-engine, which only
+disappointed him, as he stated, in consequence of the inefficiency of
+the feed-pumps. The second was that built under the authority of the
+Minister Choiseul, and cost 20,000 livres. Cugnot received from the
+French Government a pension of 600 livres. He died in 1804, at the age
+of seventy-nine years.
+
+Watt, at a very early period, proposed to apply his own engine to
+locomotion, and contemplated using either a non-condensing engine or
+an air-surface condenser. He actually included the locomotive-engine
+in his patent of 1784; and his assistant, Murdoch, in the same year,
+made a working-model locomotive (Fig. 45), which was capable of
+running at a rapid rate. This model, now deposited in the Patent
+Museum at South Kensington, London, had a flue-boiler, and its
+steam-cylinder was three-fourths of an inch in diameter, and the
+stroke of piston 2 inches. The driving-wheels were 9-1/2 inches
+diameter.
+
+[Illustration: FIG. 45.--Murdoch's Model, 1784.]
+
+Nothing was, however, done on a larger scale by either Watt or
+Murdoch, who both found more than enough to claim their attention in
+the construction and introduction of other engines. Murdoch's model is
+said to have run from 6 to 8 miles an hour, its little driving-wheels
+making from 200 to 275 revolutions per minute. As is seen in the
+sketch, this model was fitted with the same form of engine, known as
+the "grasshopper-engine," which was used in the United States by
+Oliver Evans.
+
+"To Oliver Evans," says Dr. Ernest Alban, the distinguished German
+engineer, "was it reserved to show the true value of a long-known
+principle, and to establish thereon a new and more simple method of
+applying the power of steam--a method that will remain an eternal
+memorial to its introducer." Dr. Alban here refers to the earliest
+permanently successful introduction of the non-condensing
+high-pressure steam-engine.
+
+OLIVER EVANS, one of the most ingenious mechanics that America has
+ever produced, was born at Newport, Del., in 1755 or 1756, the son of
+people in very humble circumstances.
+
+[Illustration: Oliver Evans.]
+
+He was, in his youth, apprenticed to a wheelwright, and soon exhibited
+great mechanical talent and a strong desire to acquire knowledge. His
+attention was, at an early period, drawn to the possible application
+of the power of steam to useful purposes by the boyish pranks of one
+of his comrades, who, placing a small quantity of water in a
+gun-barrel, and ramming down a tight wad, put the barrel in the fire
+of a blacksmith's forge. The loud report which accompanied the
+expulsion of the wad was an evidence to young Evans of great and (as
+he supposed) previously undiscovered power.
+
+Subsequently meeting with a description of a Newcomen engine, he at
+once noticed that the elastic force of confined steam was not there
+utilized. He then designed the non-condensing engine, in which the
+power was derived exclusively from the tension of high-pressure steam,
+and proposed its application to the propulsion of carriages.
+
+About the year 1780, Evans joined his brothers, who were millers by
+occupation, and at once employed his inventive talent in improving the
+details of mill-work, and with such success as to reduce the cost of
+attendance one-half, and also to increase the fineness of the flour
+made. He proved himself a very expert millwright.
+
+In 1786 he applied to the Pennsylvania Legislature for a patent for
+the application of the steam-engine to driving mills, and to the
+steam-carriage, but was refused it. In 1800 or 1801, Evans, after
+consultation with Professor Robert Patterson, of the University of
+Pennsylvania, and getting his approval of the plans, commenced the
+construction of a steam-carriage to be driven by a non-condensing
+engine. He soon concluded, however, that it would be a better scheme,
+pecuniarily, to adapt his engine, which was novel in form and of small
+first cost, to driving mills; and he accordingly changed his plans,
+and built an engine of 6 inches diameter of cylinder and 18 inches
+stroke of piston, which he applied with perfect success to driving a
+plaster-mill.
+
+This engine, which he called the "Columbian Engine," was of a peculiar
+form, as seen in Fig. 46. The beam is supported at one end by a
+rocking column; at the other, it is attached directly to the
+piston-rod, while the crank lies beneath the beam, the connecting-rod,
+1, being attached to the latter at the extreme end. The head of the
+piston-rod is compelled to rise and fall in a vertical line by the
+"Evans's parallelogram"--a kind of parallel-motion very similar to
+one of those designed by Watt. In the sketch (Fig. 46), 2 is the
+crank, 3 the valve-motion, 4 the steam-pipe from the boiler, _E_, 5 6
+7 the feed-pipe leading from the pump, _F_. _A_ is the boiler. The
+flame from the fire on the grate, _H_, passes under the boiler between
+brick walls, and back through a central flue to the chimney, _I_.
+
+[Illustration: FIG. 46.--Evans's Non-condensing Engine, 1800.]
+
+Subsequently, Evans continued to extend the applications of his engine
+and to perfect its details; and, others following in his track, the
+non-condensing engine is to-day fulfilling the predictions which he
+made 70 years ago, when he said:
+
+"I have no doubt that my engines will propel boats against the current
+of the Mississippi, and wagons on turnpike roads, with great
+profit...."
+
+"The time will come when people will travel in stages moved by
+steam-engines from one city to another, almost as fast as birds can
+fly, 15 or 20 miles an hour.... A carriage will start from Washington
+in the morning, the passengers will breakfast at Baltimore, dine at
+Philadelphia, and sup in New York the same day....
+
+"Engines will drive boats 10 or 12 miles an hour, and there will be
+hundreds of steamers running on the Mississippi, as predicted years
+ago."[45]
+
+  [45] Evans's prediction is less remarkable than that of Darwin,
+  elsewhere quoted.
+
+In 1804, Evans applied one of his engines in the transportation of a
+large flat-bottomed craft, built on an order of the Board of Health of
+Philadelphia, for use in clearing some of the docks along the
+water-front of the city. Mounting it on wheels, he placed in it one of
+his 5-horse power engines, and named the odd machine (Fig. 47)
+"Oruktor Amphibolis." This steam dredging-machine, weighing about
+40,000 pounds, was then propelled very slowly from the works, up
+Market Street, around to the Water-Works, and then launched into the
+Schuylkill. The engine was then applied to the paddle-wheel at the
+stern, and drove the craft down the river to its confluence with the
+Delaware.
+
+[Illustration: FIG. 47.--Evans's "Oruktor Amphibolis," 1804.]
+
+In September of the same year, Evans laid before the Lancaster
+Turnpike Company a statement of the estimated expenses and profits of
+steam-transportation on the common road, assuming the size of the
+carriage used to be sufficient for transporting 100 barrels of flour
+50 miles in 24 hours, and placed in competition with 10 wagons drawn
+by 5 horses each.
+
+In the sketch above given of the "Oruktor Amphibolis," the engine is
+seen to resemble that previously described. The wheel, _A_, is driven
+by a rod depending from the end of a beam, _B' B_, the other end of
+which is supported at _E_ by the frame, _E F G_. The body of the
+machine is carried on wheels, _K K_, driven by belts, _M M_, from the
+pulley on the shaft carrying _A_. The paddle-wheel is seen at _W_.
+Evans had some time previously sent Joseph Sampson to England with
+copies of his plans, and by him they were shown to Trevithick, Vivian,
+and other British engineers.
+
+Among other devices, the now familiar Cornish boiler, having a single
+internal flue, and the Lancashire boiler, having a pair of internal
+flues, were planned and used by Evans.
+
+At about the time that he was engaged on his steam dredging-machine,
+Evans communicated with Messrs. McKeever & Valcourt, who contracted
+with him to build an engine for a steam-vessel to ply between New
+Orleans and Natchez on the Mississippi, the hull of the vessel to be
+built on the river, and the machinery to be sent to the first-named
+city to be set up in the boat. Financial difficulties and low water
+combined to prevent the completion of the steamer, and the engine was
+set at work driving a saw-mill, where, until the mill was destroyed by
+fire, it sawed lumber at the rate of 250 feet of boards per hour.
+
+Evans never succeeded in accomplishing in America as great a success
+as had rewarded Watt in Great Britain; but he continued to build
+steam-engines to the end of his life, April 19, 1819, and was
+succeeded by his sons-in-law, James Rush and David Muhlenberg.
+
+He exhibited equal intelligence and ingenuity in perfecting the
+processes of milling, and in effecting improvements in his own
+business, that of the millwright. When but twenty-four years old, he
+invented a machine for making the wire teeth used in cotton and
+woolen cards, turning them out at the rate of 3,000 per minute. A
+little later he invented a card-setting machine, which cut the wire
+from the reel, bent the teeth, and inserted them. In milling, he
+invented a whole series of machines and attachments, including the
+elevator, the "conveyor," the "hopper-box," the "drill," and the
+"descender," and enabled the miller to make finer flour, gaining over
+20 pounds to the barrel, and to do this at half the former cost of
+attendance. The introduction of his improvements into Ellicott's
+mills, near Baltimore, where 325 barrels of flour were made per day,
+was calculated to have saved nearly $5,000 per year in cost of labor,
+and over $30,000 by increasing the production. He wrote "The Young
+Steam-Engineer's Guide," and a work which remained standard many years
+after his death, "The Young Millwright's Guide." Less fortunate than
+his transatlantic rival, he was nevertheless equally deserving of
+fame. He has sometimes been called "The Watt of America."
+
+The application of steam to locomotion on the common road was much
+more successful in Great Britain than in the United States. As early
+as 1786, William Symmington, subsequently more successful in his
+efforts to introduce steam for marine propulsion, assisted by his
+father, made a working model of a steam-carriage, which did not,
+however, lead to important results.
+
+In 1802, Richard Trevithick, a pupil of Murdoch's, who afterward
+became well known in connection with the introduction of railroads,
+made a model steam-carriage, which was patented in the same year. The
+model may still be seen in the Patent Museum at South Kensington.[46]
+
+  [46] _See_ "Life of Trevithick."
+
+In this engine, high-pressure steam was employed, and the condenser
+was dispensed with. The boiler was of the form devised by Evans, and
+was subsequently generally used in Cornwall, where it was called the
+"Trevithick Boiler." The engine had but one cylinder, and the
+piston-rod drove a "cross-tail," working in guides, which was
+connected with a "cross-head" on the opposite side of the shaft by two
+"side-rods." The connecting-rod was attached to the cross-head and the
+crank, "returning" toward the cylinder as the shaft lay between the
+latter and the cross-head. This was probably the first example of the
+now common "return connecting-rod engine." The connection between the
+crank-shaft and the wheels of the carriage was effected by gearing.
+The valve-gear and the feed-pumps were worked from the engine-shaft.
+The inventor proposed to secure his wheels against slipping by
+projecting bolts, when necessary, through the rim of the wheel into
+the ground. The first carriage of full size was built by Trevithick
+and Vivian at Camborne, in 1803, and, after trial, was taken to
+London, where it was exhibited to the public. _En route_, it was
+driven by its own engines to Plymouth, 90 miles from Camborne, and
+then shipped by water. It is not known whether the inventor lost faith
+in his invention; but he very soon dismantled the machine, sold the
+engine and carriage separately, and returned to Cornwall, where he
+soon began work on a railroad-locomotive.
+
+In 1821, Julius Griffiths, of Brompton, Middlesex, England, patented a
+steam-carriage for the transportation of passengers on the highway.
+His first road-locomotive was built in the same year by Joseph Bramah,
+one of the ablest mechanics of his time. The frame of the carriage
+carried a large double coach-body between the two axles, and the
+machinery was mounted over and behind the rear axle. One man was
+stationed on a rear platform, to manage the engine and to attend to
+the fire, and another, stationed in front of the body of the coach,
+handled the steering-wheel. The boiler was composed of horizontal
+water-tubes and steam-tubes, the latter being so situated as to
+receive heat from the furnace-gases _en route_ to the chimney, and
+thus to act as a superheater. The wheels were driven, by means of
+intermediate gearing, by two steam-engines, which, with their
+attachments, were suspended on helical springs, to prevent injury by
+jars and shocks. An air-surface condenser was used, consisting of
+flattened thin metal tubes, cooled by the contact of the external air,
+and discharging the water of condensation, as it accumulated within
+them, into a feed-pump, which, in turn, forced it into the lowest row
+of tubes in the boiler.
+
+The boiler did not prove large enough for continuous work; but the
+carriage was used experimentally, now and then, for a number of years.
+
+During the succeeding ten years the adaptation of the steam-engine to
+land-transportation continued to attract more and more attention, and
+experimental road-engines were built with steadily-increasing
+frequency. The defects of these engines revealing themselves on trial,
+they were one by one remedied, and the road-locomotive gradually
+assumed a shape which was mechanically satisfactory. Their final
+introduction into general use seemed at one time only a matter of
+time; their non-success was due to causes over which the legislator
+and the general public, and not the engineer, had control, as well as
+to the development of steam-transportation on a rival plan.
+
+In 1822, David Gordon patented a road-engine, but it is not known
+whether it was ever built. At about the same time, Mr. Goldsworthy
+Gurney, who subsequently took an active part in their introduction,
+stated, in his lectures, that "elementary power is capable of being
+applied to propel carriages along common roads with great political
+advantage, and the floating knowledge of the day places the object
+within reach." He made an ammonia-engine--probably the first ever
+made--and worked it so successfully, that he made use of it in driving
+a little locomotive.
+
+Two years later, Gordon patented a curious arrangement, which,
+however, had been proposed twelve years earlier by Brunton, and was
+again proposed afterward by Gurney, and others. This consisted in
+fitting to the engine a set of jointed legs, imitating, as nearly as
+the inventor could make them, the action of a horse's legs and feet.
+Such an arrangement was actually experimented with until it was found
+that they could not be made to work satisfactorily, when it was also
+found that they were not needed.
+
+During the same season, Burstall & Hill made a steam-carriage, and
+made many unsuccessful attempts to introduce their plan. The engine
+used was like that of Evans, except that the steam-cylinder was placed
+at the end of the beam, and the crank-shaft under the middle. The
+front and rear wheels were connected by a longitudinal shaft and bevel
+gearing. The boiler was found to have the usual defect, and would only
+supply steam for a speed of three or four miles an hour. The result
+was a costly failure. W. H. James, of London, in 1824-'25, proposed
+several devices for placing the working parts, as well as the body of
+the carriage, on springs, without interfering with their operation,
+and the Messrs. Seaward patented similar devices. Samuel Brown, in
+1826, introduced a gas-engine, in which the piston was driven by the
+pressure produced by the combustion of gas, and a vacuum was secured
+by the condensation of the resulting vapor. Brown built a locomotive
+which he propelled by this engine. He ascended Shooter's Hill, near
+London, and the principal cause of his ultimate failure seems to have
+been the cost of operating the engine.
+
+From this date forward, during several years, a number of inventors
+and mechanics seem to have devoted their whole time to this promising
+scheme. Among them, Burstall & Hill, Gurney, Ogle & Summers, Sir
+Charles Dance, and Walter Hancock, were most successful.
+
+Gurney, in the year 1827, built a steam-carriage, which he kept at
+work nearly two years in and about London, and sometimes making long
+journeys. On one occasion he made the journey from Meksham to Cranford
+Bridge, a distance of 85 miles, in 10 hours, including all stops. He
+used the mechanical legs previously adopted by Brunton and by Gordon,
+but omitted this rude device in those engines subsequently built.
+
+Gurney's engine of 1828 is of interest to the engineer as exhibiting a
+very excellent arrangement of machinery, and as having one of the
+earliest of "sectional boilers." The latter was of peculiar form, and
+differed greatly in design from the sectional boiler invented a
+quarter of a century earlier by John Stevens, in the United States.
+
+[Illustration: FIG. 48.--Gurney's Steam-Carriage.]
+
+In the sketch (Fig. 48) this boiler is seen at the right. It was
+composed of bent [<]-shaped tubes, _a a_, connected to two cylinders,
+_b b_, the upper one of which was a steam-chamber. Vertical tubes
+connected these two chambers, and permitted a complete and regular
+circulation of the water. A separate reservoir, called a separator,
+_d_, was connected with these chambers by pipes, as shown. From the
+top of this separator a steam-pipe, _e e e_, conveyed steam to the
+engine-cylinders at _f_. The cranks, _g_, on the rear axle were turned
+by the engines, and the eccentric, _h_, on the axle drove the
+valve-gearing and the valve, _i_. The link, _k l_, being moved by a
+line, _l l_, led from the driver's seat, the carriage was started,
+stopped, or reversed, by throwing the upper end of the link into gear
+with the valve-stem, by setting the link midway between its upper and
+lower positions, or by raising it until the lower end, coming into
+action on the valve-stem, produced a reverse motion of the valve. The
+pin on which this link vibrated is seen at the centre of its
+elliptical strap. The throttle-valve, _o_, by which the supply of
+steam to the engine was adjusted, was worked by the lever, _n_. The
+exhaust-pipe, _p_, led to the tank, _q_, and the uncondensed vapor
+passed to the chimney, _s s_, by the pipe, _r r_. The force-pump, _u_,
+taking feed-water from the tank, _t_, supplied it to the boiler by the
+pipe, _x x x_, which, _en route_, was coiled up to form a "heater"
+directly above the boiler. The supply was regulated by the cock, _y_.
+The attendant had a seat at _z_. A blast-apparatus, 1, was driven by
+an independent engine, 2 3, and produced a forced blast, which was led
+to the boiler-furnace through the air-duct, 5 5; 4 4 represents the
+steam-pipe to the little blowing-engine. The steering-wheel, 6, was
+directed by a lever, 7, and the change of direction of the perch, 8,
+which turned about a king-bolt at 9, gave the desired direction to the
+forward wheels and to the carriage.
+
+This seems to have been one of the best designs brought out at that
+time. The boiler, built to carry 70 pounds, was safe and strong, and
+was tested up to 800 pounds pressure. A forced draught was provided.
+The engines were well placed, and of good design. The valve was
+arranged to work the steam with expansion from half-stroke. The
+feed-water was heated, and the steam slightly superheated. The boiler
+here used has been since reproduced under new names by later
+inventors, and is still used with satisfactory results. Modifications
+of the "pipe-boiler" were made by several other makers of
+steam-carriages also. Anderson & James made their boilers of
+lap-welded iron tubes of one inch internal diameter and one-fifth inch
+thick, and claimed for them perfect safety. Such tubes should have
+sufficient strength to sustain a pressure of 20,000 pounds per square
+inch. If made of such good iron as the makers claimed to have put into
+them, "which worked like lead," they would, as was also claimed, when
+ruptured, open by tearing, and discharge their contents without
+producing the usual disastrous consequences of boiler explosions.
+
+The primary principle of the sectional boiler was then well
+understood. The boilers of Ogle & Summers were made up of pairs of
+upright tubes, set one within the other, the intervening space being
+filled with water and steam, and the flame passing through the inner
+and around the outer tube of each pair.
+
+One of the engines of Sir James Anderson and W. H. James was built in
+1829. It had two 3-1/2-inch steam-cylinders, driving the rear wheels
+independently. In James's earlier plan of 1824-'25, a pair of
+cylinders was attached to each of the two halves into which the rear
+axle was divided, and were arranged to drive cranks set at
+right-angles with each other. The later machine weighed 3 tons, and
+carried 15 passengers, on a rough graveled road across the Epping
+Forest, at the rate of from 12 to 15 miles per hour. Steam was carried
+at 300 pounds. Several tubes gave way in the welds, but the carriage
+returned, carrying 24 passengers at the rate of 7 miles per hour. On a
+later trial, with new boilers, the carriage again made 15 miles per
+hour. It was, however, subject to frequent accidents, and was finally
+withdrawn.
+
+WALTER HANCOCK was the most successful and persevering of all those
+who attempted the introduction of steam on the common road. He had, in
+1827, patented a boiler of such peculiar form, that it deserves
+description. It consisted of a collection of flat chambers, of which
+the walls were of boiler-plate. These chambers were arranged side by
+side, and connected laterally by tubes and stays, and all were
+connected by short vertical tubes to a horizontal large pipe placed
+across the top of the boiler-casing, and serving as a steam-drum or
+separator. This earliest of "sheet flue-boilers" did excellent
+service on Hancock's steam-carriages, where experience showed that
+there was little or no danger of disruptive explosions.
+
+Hancock's first steam-carriage was mounted on three wheels, the
+leading-wheel arranged to swivel on a king-bolt, and driven by a pair
+of oscillating cylinders connected with its axle, which was "cranked"
+for the purpose. The engines turned with the steering-wheel. This
+carriage was by no means satisfactory, but it was used for a long
+time, and traveled many hundreds of miles without once failing to do
+the work assigned it.
+
+By this time there were a half-dozen steam-carriages under
+construction for Hancock, for Ogle & Summers, and for Sir Charles
+Dance.
+
+In 1831, Hancock placed a new carriage on a route between London and
+Stratford, where it ran regularly for hire. Dance, in the same season,
+started another on the line between Cheltenham and Gloucester, where
+it ran from February 21st to June 22d, traveling 3,500 miles and
+carrying 3,000 passengers, running the 9 miles in 55 minutes usually,
+and sometimes in three-quarters of an hour, and never meeting with an
+accident, except the breakage of an axle in running over heaps of
+stones which had been purposely placed on the road by enemies of the
+new system of transportation. Ogle & Summers's carriage attained a
+speed, as testified by Ogle before a committee of the House of
+Commons, of from 32 to 35 miles an hour, and on a rising grade, near
+Southampton, at 24-1/2 miles per hour. They carried 250 pounds of
+steam, ran 800 miles, and met with no accident. Colonel Macerone, in
+1833, ran a steam-carriage of his own design from London to Windsor
+and back, with 11 passengers, a distance of 23-1/2 miles, in 2 hours.
+Sir Charles Dance, in the same year, ran his carriage 16 miles an
+hour, and made long excursions at the rate of 9 miles an hour. Still
+another experimenter, Heaton, ascended Lickey Hill, between Worcester
+and Birmingham, on gradients of one in eight and one in nine, in
+places; this was considered one of the worst pieces of road in
+England. The carriage towed a coach containing 20 passengers.
+
+Of all these, and many others, Hancock, however, had most marked
+success. His coach, called the "Infant," which was set at work in
+February, 1831, was, a year later, plying between London "City" and
+Paddington. Another, called the "Era," was built for the London and
+Greenwich Steam-Carriage Company, which was mechanically a success.
+The company, however, was financially unsuccessful. In October, 1832,
+the "Infant" ran to Brighton from London, carrying a party of 11, at
+the rate of 9 miles per hour, ascending Redhill at a speed of 5 miles.
+They steamed 38 miles the first day, stopping at night at Hazledean,
+and reached Brighton next day, running 11 miles per hour. Returning
+with 15 passengers, the coach ran 1 mile in less than 4 minutes, and
+made 10 miles in 55 minutes. A run from Stratford to Brighton was made
+in less than 10 hours, at an average speed of 12 miles an hour running
+time, the actual running time being less than 6 hours. The next year
+another carriage, the "Enterprise," was put on the road to Paddington
+by Hancock for another company, and ran regularly over two weeks; but
+this company was also unsuccessful. In the summer of 1833 he brought
+out still another steam-coach, the "Autopsy" (Fig. 49), which he ran
+to Brighton, and then, returning to London, man[oe]uvred the carriage
+in the crowded streets without difficulty or accident. He went about
+the streets of London at all times, and without hesitation. The coach
+next ran between Finsbury Square and Pentonville regularly for four
+weeks, without accident or delay. In the sketch, a part of the side is
+broken away to show the machinery. The boiler, _A B_, supplies steam
+through the steam-pipe, _H K_, to the steam-engine, _C D_, which is
+coupled to the crank-shaft, _F_. _E_ is the feed-pump. The rear axle
+is turned by the endless chain seen connecting it with the
+engine-shaft, and the rear wheels, _S_, are thus driven. A blower,
+_T_, gives a forced draught. The driver sits at _M_, steering by the
+wheel, _N_, which is coupled to the larger wheel, _P_, and thus turns
+the forward axle into any desired position. In 1834, Hancock built a
+steam "drag" on an Austrian order, which, carrying 10 persons and
+towing a coach containing 6 passengers, was driven through the city
+beyond Islington, making 14 miles an hour on a level, and 8 miles or
+more on rising ground. In the same year he built the "Era," and, in
+August, put the "Autopsy" on with it, to make a steam-line to
+Paddington. These coaches ran until the end of November, carrying
+4,000 passengers, at a usual rate of speed of 12 miles per hour. He
+then sent the "Era" to Dublin, where, on one occasion, it ran 18 miles
+per hour.
+
+[Illustration: FIG. 49.--Hancock's "Autopsy," 1833.]
+
+In 1835 a large carriage, the "Erin," was completed, which was
+intended to carry 20 passengers. It towed three omnibuses and a
+stage-coach, with 50 passengers, on a level road, at the speed of 10
+miles an hour. It drew an omnibus with 18 passengers through
+Whitehall, Charing Cross, and Regent Street, and out to Brentford,
+running 14 miles an hour. It ran also to Reading, making 38 miles,
+with the same load, in 3 hours and 8 minutes running time. The stops
+_en route_ occupied a half-hour. The same carriage made 75 miles to
+Marlborough in 7-1/2 hours running time, stopping 4-1/2 hours on the
+road, in consequence of having left the tender and supplies behind.
+
+In May, 1836, Hancock put all his carriages on the Paddington road,
+and ran regularly for over five months, running 4,200 miles in 525
+trips to Islington, 143 to Paddington, and 44 to Stratford, passing
+through the city over 200 times. The carriages averaged 5 hours and 17
+or 18 minutes daily running time. A light steam-phaeton, built in
+1838, for his own use, made 20 miles an hour, and was driven about the
+city, and among horses and carriages, without causing annoyance or
+danger. Its usual speed was about 10 miles an hour. Altogether,
+Hancock built nine steam-carriages, capable of carrying 116 passengers
+in addition to the regular attendants.[47]
+
+  [47] For a detailed account of the progress of steam on the highway,
+  _see_ "Steam on Common Roads," etc., by Young, Holley, & Fisher,
+  London, 1861.
+
+In December, 1833, about 20 steam-carriages and traction road-engines
+were running, or were in course of construction, in and near London.
+In our own country, the roughness of roads discouraged inventors;
+and in Great Britain even, the successful introduction of
+road-locomotives, which seemed at one time almost an accomplished
+fact, finally met with so many obstacles, that even Hancock, the most
+ingenious, persistent, and successful constructor, gave up in despair.
+Hostile legislation procured by opposing interests, and the rapid
+progress of steam-locomotion on railroads, caused this result.
+
+In consequence of this interruption of experiment, almost nothing was
+done during the succeeding quarter of a century, and it is only within
+a few years that anything like a business success has been founded
+upon the construction of road-locomotives, although the scheme seems
+to have been at no time entirely given up.
+
+The opposition of coach-proprietors, and of all classes having an
+interest in the old lines of coaches, was most determined, and the
+feeling evinced by them was intensely bitter; but the advocates of the
+new system of transportation were equally determined and persevering,
+and, having right on their side, and the pecuniary advantage of the
+public as their object, they would probably have succeeded ultimately,
+except for the introduction of the still better method of
+transportation by rail.
+
+In the summer of 1831, when the war between the two parties was at its
+height, a committee of the British House of Commons made a very
+complete investigation of the subject. This committee reported that
+they had become convinced that "the substitution of inanimate for
+animal power, in draught on common roads, is one of the most important
+improvements in the means of internal communication ever introduced."
+They considered its practicability to have been "fully established,"
+and predicted that its introduction would "take place more or less
+rapidly, in proportion as the attention of scientific men shall be
+drawn, by public encouragement, to further improvement." The success
+of the system had, as they stated, been retarded by prejudice, adverse
+interests, and prohibitory tolls; and the committee remark: "When we
+consider that these trials have been made under the most unfavorable
+circumstances, at great expense, in total uncertainty, without any of
+those guides which experience has given to other branches of
+engineering; that those engaged in making them are persons looking
+solely to their own interests, and not theorists attempting the
+perfection of ingenious models; when we find them convinced, after
+long experience, that they are introducing such a mode of conveyance
+as shall tempt the public, by its superior advantages, from the use of
+the admirable lines of coaches which have been generally established,
+it surely cannot be contended that the introduction of steam-carriages
+on common roads is, as yet, an uncertain experiment, unworthy of
+legislative attention."
+
+Farey, one of the most distinguished mechanical engineers of the
+time, testified that he considered the practicability of such a system
+as fully established, and that the result would be its general
+adoption. Gurney had run his carriage between 20 and 30 miles an hour;
+Hancock could sustain a speed of 10 miles; Ogle had run his coach 32
+to 35 miles an hour, and ascended a hill rising 1 in 6 at the speed of
+24-1/2 miles. Summers had traveled up a hill having a gradient of 1 in
+12, with 19 passengers, at the rate of speed of 15 miles per hour; he
+had run 4-1/2 hours at 30 miles an hour. Farey thought that
+steam-coaches would be found to cost one-third as much as the
+stage-coaches in use. The steam-carriages were reported to be safer
+than those drawn by horses, and far more manageable; and the
+construction of boilers adopted--the "sectional" boiler, as it is now
+called--completely insured against injury by explosion, and the
+dangers and inconveniences arising from the frightening of horses had
+proved to be largely imaginary. The wear and tear of roads were found
+to be less than with horses, while with broad wheel-tires the
+carriages acted beneficially as road-rollers. The committee finally
+concluded:
+
+"1. That carriages can be propelled by steam on common roads at an
+average rate of 10 miles per hour.
+
+"2. That at this rate they have conveyed upward of 14 passengers.
+
+"3. That their weight, including engine, fuel, water, and attendants,
+may be under three tons.
+
+"4. That they can ascend and descend hills of considerable inclination
+with facility and safety.
+
+"5. That they are perfectly safe for passengers.
+
+"6. That they are not (or need not be, if properly constructed)
+nuisances to the public.
+
+"7. That they will become a speedier and cheaper mode of conveyance
+than carriages drawn by horses.
+
+"8. That, as they admit of greater breadth of tire than other
+carriages, and as the roads are not acted on so injuriously as by the
+feet of horses in common draught, such carriages will cause less wear
+of roads than coaches drawn by horses.
+
+"9. That rates of toll have been imposed on steam-carriages, which
+would prohibit their being used on several lines of road, were such
+charges permitted to remain unaltered."
+
+THE RAILROAD, which now, by the adaptation of steam to the propulsion
+of its carriages, became the successful rival of the system of
+transportation of which an account has just been given, was not a new
+device. It, like all other important changes of method and great
+inventions, had been growing into form for ages. The ancients were
+accustomed to lay down blocks of stone as a way upon which their
+heavily-loaded wagons could be drawn with less resistance than on the
+common road. This practice was gradually so modified as to result in
+the adoption of the now universally-practised methods of paving and
+road-making. The old tracks, bearing the marks of heavy traffic, are
+still seen in the streets of the unearthed city of Pompeii.
+
+In the early days of mining in Great Britain, the coal or the ore was
+carried from the mine to the vessel in which it was to be embarked in
+sacks on the backs of horses. Later, the miners laid out wagon-roads,
+and used carts and wagons drawn by horses, and the roads were paved
+with stone along the lines traversed by the wheels of the vehicles.
+Still later (about 1630), heavy planks or squared timber took the
+place of the stone, and were introduced into the north of England by a
+gentleman of the name of Beaumont, who had transferred his property
+there from the south. A half century later, the system had become
+generally introduced. By the end of the eighteenth century the
+construction of these "tram-ways" had become well-understood, and the
+economy which justified the expenditure of considerable amounts of
+money in making cuts and in filling, to bring the road to a uniform
+grade, had become well-recognized. Arthur Young, writing at this time,
+says the coal wagon-roads were "great works, carried over all sorts
+of inequalities of ground, so far as the distance of nine or ten
+miles," and that, on these tram-ways of timber, "one horse is able to
+draw, and that with ease, fifty or sixty bushels of coals." The
+wagon-wheels were of cast-iron, and made with grooved rims, which
+fitted the rounded tops of the wooden rails. But these wooden rails
+were found subject to rapid decay, and at Whitehaven, in 1738, they
+were protected from wear by cast-iron plates laid upon them, and this
+improvement rapidly became known and adopted. A tram-road, laid down
+at Sheffield for the Duke of Norfolk, in 1776, was made by laying
+angle-bars of cast-iron on longitudinal sleepers of timber; another,
+built by William Jessup in Leicestershire, in 1789, had an edge-rail,
+and the wheels were made with flanges, like those used to-day. The
+coned "tread" of the wheel, which prevents wear of flanges and reduces
+resistance, was the invention of James Wright, of Columbia, Pa., 40
+years later. The modern railroad was simply the result of this gradual
+improvement of the permanent way, and the adaptation of the
+steam-engine to the propulsion of its wagons.
+
+At the beginning of the nineteenth century, therefore, the
+steam-engine had been given a form which permitted its use, and the
+railroad had been so far perfected that there were no difficulties to
+be anticipated in the construction of the permanent way, and inventors
+were gradually preparing, as has been seen, to combine these two
+principal elements into one system. Railroads had been introduced in
+all parts of Great Britain, some of them of considerable length, and
+involving the interests of so many private individuals that they were
+necessarily constructed under the authorization of legal enactments.
+In the year 1805 the Merstham Railway was opened to traffic, and it is
+stated that on that occasion one horse drew a train of 12 wagons,
+carrying 38 tons of stone, on a "down gradient" of 1 in 120, at the
+rate of 6 miles per hour.
+
+[Illustration: Richard Trevithick.]
+
+[Illustration: FIG. 50.--Trevithick's Locomotive, 1804.]
+
+RICHARD TREVITHICK was the first engineer to apply steam-power to the
+haulage of loads on the railroad. Trevithick was a Cornishman by
+birth, a native of Redruth. He was naturally a skillful mechanic, and
+was placed by his father with Watt's assistant, Murdoch, who was
+superintending the erection of pumping-engines in Cornwall; and from
+that ingenious and accomplished engineer young Trevithick probably
+acquired both the skill and the knowledge which, with his native
+talent, enterprise, and industry, enabled him to accomplish the work
+which has made him famous. He was soon intrusted with the erection and
+management of large pumping-engines, and subsequently went into the
+business of constructing steam-engines with another engineer, Edward
+Bull, who took an active part, with the Hornblowers and others, in
+opposing the Boulton & Watt patents. The termination of the suits
+which established the validity of Watt's patent put an end to their
+business, and Trevithick looked about for other work, and, not long
+after, entered into partnership with a relative, Andrew Vivian, who
+was also a skillful mechanic; they together designed and patented the
+steam-carriage already referred to. Its success was sufficiently
+satisfactory to awaken strong confidence of a perfect success on the
+now common tram-roads; and Trevithick, in February, 1804, had
+completed a "locomotive" engine to work on the Welsh Pen-y-darran
+road. This engine (Fig. 50) had a cylindrical flue-boiler, _A_, like
+that designed by Oliver Evans, and a single steam-cylinder, _B_, set
+vertically into the steam-space of the boiler, and driving the
+outside cranks, _L_, on the rear axle of the engine by very long
+connecting-rods, _D_, attached to its cross-head at _E_. The
+guide-bars, _I_, were stayed by braces leading to the opposite end of
+the boiler. No attempt was made to condense the exhaust-steam, which
+was discharged into the smoke-pipe. The pressure of steam adopted was
+40 pounds per square inch; but Trevithick had already made a number of
+non-condensing engines on which he carried from 50 to 145 pounds
+pressure.
+
+In the year 1808, Trevithick built a railroad in London, on what was
+known later as Torrington Square, or Euston Square, and set at work a
+steam-carriage, which he called "Catch-me-who-can." This was a very
+plain and simple machine. The steam-cylinder was set vertically in the
+after-end of the boiler, and the cross-head was connected to two rods,
+one on either side, driving the hind pair of wheels. The exhaust-steam
+entered the chimney, aiding the draught. This engine, weighing about
+10 tons, made from 12 to 15 miles an hour on the circular railway in
+London, and was said by its builder to be capable of making 20 miles
+an hour. The engine was finally thrown from the track, after some
+weeks of work, by the breaking of a rail, and, Trevithick's funds
+having been expended, it was never replaced. This engine had a
+steam-cylinder 14-1/2 inches in diameter, and a stroke of piston of 4
+feet. Trevithick used no device to aid the friction of the wheels on
+the rails in giving pulling-power, and seems to have understood that
+none was needed. This plan of working a locomotive-engine without such
+complications as had been proposed by other engineers was, however,
+subsequently patented, in 1813, by Blackett & Hedley. The latter was
+at one time Trevithick's agent, and was director of Wylam Colliery, of
+which Mr. Blackett was proprietor.
+
+Trevithick applied his high-pressure non-conducting engine not only to
+locomotives, but to every purpose that opportunity offered him. He put
+one into the Tredegar Iron-Works, to drive the puddle-train, in 1801.
+This engine had a steam-cylinder 28 inches in diameter, and 6 feet
+stroke of piston; a boiler of cast-iron, 6-3/4 feet in diameter and 20
+feet long, with a wrought-iron internal tube, 3 feet in diameter at
+the furnace-end and 24 inches beyond the furnace. The steam-pressure
+ranged from 50 to 100 pounds per square inch. The valve was a four-way
+cock. The exhaust-steam was carried into the chimney, passing through
+a feed-water heater _en route_. This engine was taken down in
+1856.[48]
+
+  [48] "Life of Trevithick."
+
+In 1803, Trevithick applied his engine to driving rock-drills, and
+three years later made a large contract with the Trinity Board for
+dredging in the Thames, and constructed steam dredging-machines for
+the work, of the form which is still most generally used in Great
+Britain, although rarely seen in the United States--the
+"chain-and-bucket dredger."
+
+A little later, Trevithick was engaged upon the first and unsuccessful
+attempt to carry a tunnel under the Thames, at London; but no sooner
+had that costly scheme been given up, than he returned to his favorite
+pursuits, and continued his work on interrupted schemes for
+ship-propulsion. Trevithick at last left England, spent some years in
+South America, and finally returned home and died in extreme poverty,
+April, 1833, at the age of sixty-two, without having succeeded in
+accomplishing the general introduction of any of his inventions.
+
+Trevithick was characteristically an inventor of the typical sort. He
+invented many valuable devices, but brought but few into even
+experimental use, and reaped little advantage from any of them. He was
+ingenious, a thorough mechanic, bold, active, and indefatigable; but
+his lack of persistence made his whole life, as Smiles has said, "but
+a series of beginnings."
+
+It is at about this period that we find evidence of the intelligent
+labors of another of our own countrymen--one who, in consequence of
+the unobtrusive manner in which his work was done, has never received
+the full credit to which he is entitled.
+
+COLONEL JOHN STEVENS, of Hoboken, as he is generally called, was born
+in the city of New York, in 1749; but throughout his business-life he
+was a resident of New Jersey.
+
+[Illustration: Colonel John Stevens.]
+
+His attention is said to have been first called to the application of
+steam-power by seeing the experiments of John Fitch with his steamer
+on the Delaware, and he at once devoted himself to the introduction of
+steam-navigation with characteristic energy, and with a success that
+will be indicated when we come to the consideration of that subject.
+
+But this far-sighted engineer and statesman saw plainly the
+importance of applying the steam-engine to land-transportation as well
+as to navigation; and not only that, but he saw with equal
+distinctness the importance of a well-devised and carefully-prosecuted
+scheme of internal communication by a complete system of railroads. In
+1812 he published a pamphlet containing "Documents tending to prove
+the superior advantages of Railways and Steam-Carriages over
+Canal-Navigation."[49] At this time, the only locomotive in the world
+was that of Trevithick and Vivian, at Merthyr Tydvil, and the railroad
+itself had not grown beyond the old wooden tram-roads of the
+collieries. Yet Colonel Stevens says, in this paper: "I can see
+nothing to hinder a steam-carriage moving on its ways with a velocity
+of 100 miles an hour;" adding, in a foot-note: "This astonishing
+velocity is considered here merely possible. It is probable that it
+may not, in practise, be convenient to exceed 20 or 30 miles per hour.
+Actual experiment can only determine this matter, and I should not be
+surprised at seeing steam-carriages propelled at the rate of 40 or 50
+miles an hour."
+
+  [49] Printed by T. & J. Swords, 160 Pearl Street, New York, 1812.
+
+At a yet earlier date he had addressed a memoir to the proper
+authorities, urging his plans for railroads. He proposed rails of
+timber, protected, when necessary, by iron plates, or to be made
+wholly of iron; the car-wheels were to be of cast-iron, with inside
+flanges to keep them on the track. The steam-engine was to be driven
+by steam of 50 pounds pressure and upward, and to be non-condensing.
+
+Answering the objections of Robert R. Livingston and of the State
+Commissioners of New York, he goes further into details. He gives 500
+to 1,000 pounds as the maximum weight to be placed on each wheel;
+shows that the trains, or "suits of carriages," as he calls them, will
+make their journeys with as much certainty and celerity in the darkest
+night as in the light of day; shows that the grades of proposed roads
+would offer but little resistance; and places the whole subject before
+the public with such accuracy of statement and such evident
+appreciation of its true value, that every one who reads this
+remarkable document will agree fully with President Charles King, who
+said[50] that "whosoever shall attentively read this pamphlet, will
+perceive that the political, financial, commercial, and military
+aspects of this great question were all present to Colonel Stevens's
+mind, and that he felt that he was fulfilling a patriotic duty when he
+placed at the disposal of his native country these fruits of his
+genius. The offering was not then accepted. The 'Thinker' was ahead of
+his age; but it is grateful to know that he lived to see his projects
+carried out, though not by the Government, and that, before he
+finally, in 1838, closed his eyes in death, at the great age of
+eighty-nine, he could justly feel assured that the name of Stevens, in
+his own person and in that of his sons, was imperishably enrolled
+among those which a grateful country will cherish."
+
+  [50] "Progress of the City of New York."
+
+Without having made any one superlatively great improvement in the
+mechanism of the steam-engine, like that which gave Watt his
+fame--without having the honor even of being the first to
+propose the propulsion of vessels by the modern steam-engine, or
+steam-transportation on land--he exhibited a far better knowledge of
+the science and the art of engineering than any man of his time; and
+he entertained and urged more advanced opinions and more statesmanlike
+views in relation to the economical importance of the improvement and
+the application of the steam-engine, both on land and water, than seem
+to be attributable to any other leading engineer of that time.
+
+Says Dr. King: "Who can estimate if, at that day, acting upon the
+well-considered suggestion of President Madison, 'of the signal
+advantages to be derived to the United States from a general system of
+internal communication and conveyance,' Congress had entertained
+Colonel Stevens's proposal, and, after verifying by actual experiment
+upon a small scale the accuracy of his plan, had organized such a
+'general system of internal communication and conveyance;' who can
+begin to estimate the inappreciable benefits that would have resulted
+therefrom to the comfort, the wealth, the power, and, above all, to
+the absolutely impregnable union of our great Republic and all its
+component parts? All this Colonel Stevens embraced in his views, for
+he was a statesman as well as an experimental philosopher; and whoever
+shall attentively read his pamphlet, will perceive that the political,
+financial, commercial, and military aspects of this great question
+were all present to his mind, and he felt that he was fulfilling a
+patriotic duty when he placed at the disposal of his native country
+these fruits of his genius."
+
+WILLIAM HEDLEY, who has already been referred to, seems to have been
+the first to show, by carefully-conducted experiment, how far the
+adhesion of the wheels of the locomotive-engine could be relied upon
+for hauling-power in the transportation of loads.
+
+His employer, Blackett, had applied to Trevithick for a
+locomotive-engine to haul coal-trains at the Wylam collieries; but
+Trevithick was unable, or was disinclined, to build him one, and in
+October, 1812, Hedley was authorized to attempt the construction of an
+engine. It was at about this time that Blenkinsop (1811) was trying
+the toothed rail or rack, the Messrs. Chapman (December, 1812) were
+experimenting with a towing-chain, and (May, 1813) Brunton with
+movable legs.
+
+Hedley, who had known of the success met with in the experiments of
+Trevithick with smooth wheels hauling loads of considerable weight, in
+Cornwall, was confident that equal success might be expected in the
+north-country, and built a carriage to be moved by men stationed at
+four handles, by which its wheels were turned.
+
+This carriage was loaded with heavy masses of iron, and attached to
+trains of coal-wagons on the railway. By repeated experiment, varying
+the weight of the traction-carriage and the load hauled, Hedley
+ascertained the proportion of the weight required for adhesion to that
+of the loads drawn. It was thus conclusively proven that the weight of
+his proposed locomotive-engine would be sufficient to give the
+pulling-power necessary for the propulsion of the coal-trains which it
+was to haul.
+
+When the wheels slipped in consequence of the presence of grease,
+frost, or moisture on the rail, Hedley proposed to sprinkle ashes on
+the track, as sand is now distributed from the sand-box of the modern
+engine. This was in October, 1812.
+
+Hedley now went to work building an engine with smooth wheels, and
+patented his design March 13, 1813, a month after he had put his
+engine at work. The locomotive had a cast-iron boiler, and a single
+steam-cylinder 6 inches in diameter, with a small fly-wheel. This
+engine had too small a boiler, and he soon after built a larger
+engine, with a return-flue boiler made of wrought-iron. This hauled 8
+loaded coal-wagons 5 miles an hour at first, and a little later 10,
+doing the work of 10 horses. The steam-pressure was carried at about
+50 pounds, and the exhaust, led into the chimney, where the pipe was
+turned upward, thus secured a blast of considerable intensity in its
+small chimney. Hedley also contracted the opening of the exhaust-pipe
+to intensify the blast, and was subjected to some annoyance by
+proprietors of lands along his railway, who were irritated by the
+burning of their grass and hedges, which were set on fire by the
+sparks thrown out of the chimney of the locomotive. The cost of
+Hedley's experiment was defrayed by Mr. Blackett.
+
+Subsequently, Hedley mounted his engine on eight wheels, the
+four-wheeled engines having been frequently stopped by breaking the
+light rails then in use. Hedley's engines continued in use at the
+Wylam collieries many years. The second engine was removed in 1862,
+and is now preserved at the South Kensington Museum, London.
+
+GEORGE STEPHENSON, to whom is generally accorded the honor of having
+first made the locomotive-engine a success, built his first engine at
+Killingworth, England, in 1814.
+
+[Illustration: George Stephenson.]
+
+At this time Stephenson was by no means alone in the field, for the
+idea of applying the steam-engine to driving carriages on common roads
+and on railroads was beginning, as has been seen, to attract
+considerable attention. Stephenson, however, combined, in a very
+fortunate degree, the advantages of great natural inventive talent and
+an excellent mechanical training, reminding one strongly of James
+Watt. Indeed, Stephenson's portrait bears some resemblance to that of
+the earlier great inventor.
+
+George Stephenson was born June 9, 1781, at Wylam, near
+Newcastle-upon-Tyne, and was the son of a "north-country miner." When
+still a child, he exhibited great mechanical talent and unusual love
+of study. When set at work about the mines, his attention to duty and
+his intelligence obtained for him rapid promotion, until, when but
+seventeen years of age, he was made engineer, and took charge of the
+pumping-engine at which his father was fireman.
+
+When a mere child, and employed as a herd-boy, he amused himself
+making model engines in clay, and, as he grew older, never lost an
+opportunity to learn the construction and management of machinery.
+After having been employed at Newburn and Callerton, where he first
+became "engine-man," he began to study with greater interest than ever
+the various steam-engines which were then in use; and both the
+Newcomen engine and the Watt pumping-engine were soon thoroughly
+understood by him. After having become a brakeman, he removed to
+Willington Quay, where he married, and commenced his wedded life on 18
+or 20 shillings per week. It was here that he became an intimate
+friend of the distinguished William Fairbairn, who was then working as
+an apprentice at the Percy Main Colliery, near by. The "father of the
+railroad" and the future President of the British Association were
+accustomed, at times, to "change works," and were frequently seen in
+consultation over their numerous projects. It was at Willington Quay
+that his son Robert, who afterward became a distinguished civil
+engineer, was born, October 16, 1803.
+
+In the following year Stephenson removed to Killingworth, and became
+brakeman at that colliery; but his wife soon died, and he gladly
+accepted an invitation to become engine-driver at a spinning-mill near
+Montrose, Scotland. At the end of a year he returned, on foot, to
+Killingworth with his savings (about L28), expended over one-half of
+the amount in paying his father's debts and in making his parents
+comfortable, and then returned to his old station as brakeman at the
+pit.
+
+Here he made some useful improvements in the arrangement of the
+machinery, and spent his spare hours in studying his engine and
+planning new machines. He a little later distinguished himself by
+altering and repairing an old Newcomen engine at the High Pit, which
+had failed to give satisfaction, making it thoroughly successful after
+three days' work. The engine cleared the pit, at which it had been
+vainly laboring a long time, in two days after Stephenson started it
+up.
+
+In the year 1812, Stephenson was made engine-wright of the
+Killingworth High Pit, receiving L100 a year, and it was made his duty
+to supervise the machinery of all the collieries under lease by the
+so-called "Grand Allies." It was here, and at this period, that he
+commenced a systematic course of self-improvement and the education of
+his son, and here he first began to be recognized as an inventor. He
+was full of life and something of a wag, and often made most amusing
+applications of his inventive powers: as when he placed the watch,
+which a comrade had brought him as out of repairs, in the oven "to
+cook," his quick eye having noted the fact that the difficulty arose
+simply from the clogging of the wheels by the oil, which had been
+congealed by cold.
+
+Smiles,[51] his biographer, describes his cottage as a perfect
+curiosity-shop, filled with models of engines, machines of various
+kinds, and novel apparatus. He connected the cradles of his neighbors'
+wives with the smoke-jacks in their chimneys, and thus relieved them
+from constant attendance upon their infants; he fished at night with a
+submarine lamp, which attracted the fish from all sides, and gave him
+wonderful luck; he also found time to give colloquial instruction to
+his fellow-workmen.
+
+  [51] "Lives of George and Robert Stephenson," by Samuel Smiles. New
+  York and London, 1868.
+
+He built a self-acting inclined plane for his pit, on which the
+wagons, descending loaded, drew up the empty trains; and made so many
+improvements at the Killingworth pit, that the number of horses
+employed underground was reduced from 100 to 16.
+
+Stephenson now had more liberty than when employed at the brakes, and,
+hearing of the experiments of Blackett and Hedley at Wylam, went over
+to their colliery to study their engine. He also went to Leeds to see
+the Blenkinsop engine draw, at a trial, 70 tons at the rate of 3 miles
+an hour, and expressed his opinion in the characteristic remark, "I
+think I could make a better engine than that to go upon legs." He very
+soon made the attempt.
+
+Having laid the subject before the proprietors of the lease under
+which the collieries were worked, and convinced Lord Ravensworth, the
+principal owner, of the advantages to be secured by the use of a
+"traveling engine," that nobleman advanced the money required.
+Stephenson at once commenced his first locomotive-engine, building it
+in the workshops at West Moor, assisted mainly by John Thirlwall, the
+colliery blacksmith, during the years 1813 and 1814, completing it in
+July of the latter year.
+
+This engine had a wrought-iron boiler 8 feet long and 2 feet 10 inches
+in diameter, with a single flue 20 inches in diameter. The cylinders
+were vertical, 8 inches in diameter and of 2 feet stroke of piston,
+set in the boiler, and driving a set of wheels which geared with each
+other and with other cogged wheels on the two driving-axles. A
+feed-water heater surrounded the base of the chimney. This engine drew
+30 tons on a rising gradient of 10 or 12 feet to the mile at the rate
+of 4 miles an hour. This engine proved in many respects defective, and
+the cost of its operation was found to be about as great as that of
+employing horse-power.
+
+Stephenson determined to build another engine on a somewhat different
+plan, and patented its design in February, 1815. It proved a much
+more efficient machine than the "Bluecher," the first engine.
+
+[Illustration: FIG. 51.--Stephenson's Locomotive of 1815. Section.]
+
+This second engine (Fig. 51) was also fitted with two vertical
+cylinders, _C c_, but the connecting-rods were attached directly to
+the four driving-wheels, _W W'_. To permit the necessary freedom of
+motion, "ball-and-socket" joints were adopted, to unite the rods with
+the cross-heads, _R r_, and with the cranks, _R' Y'_; and the two
+driving-axles were connected by an endless chain, _T t'_. The cranked
+axle and the outside connection of the wheels, as specified in the
+patent, were not used until afterward, it having been found impossible
+to get the cranked axles made. In this engine the forced draught
+obtained by the impulse of the exhaust-steam was adopted, doubling the
+power of the machine and permitting the use of coke as a fuel, and
+making it possible to adopt the multi-tubular boiler. Small
+steam-cylinders, _S S S_, took the weight of the engine and served as
+springs.
+
+It was at about this time that George Stephenson and Sir Humphry
+Davy, independently and almost simultaneously, invented the
+"safety-lamp," without which few mines of bituminous coal could to-day
+be worked. The former used small tubes, the latter fine wire gauze, to
+intercept the flame. Stephenson proved the efficiency of his lamp by
+going with it directly into the inflammable atmosphere of a dangerous
+mine, and repeatedly permitting the light to be extinguished when the
+lamp became surcharged with the explosive mixture which had so
+frequently proved fatal to the miners. This was in October and
+November, 1815, and Stephenson's work antedates that of the great
+philosopher.[52] The controversy which arose between the supporters of
+the rival claims of the two inventors was very earnest, and sometimes
+bitter. The friends of the young engineer raised a subscription,
+amounting to above L1,000, and presented it to him as a token of their
+appreciation of the value of his simple yet important contrivance. Of
+the two forms of lamp, that of Stephenson is claimed to be safest, the
+Davy lamp being liable to produce explosions by igniting the explosive
+gas when, by its combustion within the gauze cylinder, the latter is
+made red-hot. Under similar conditions, the Stephenson lamp is simply
+extinguished, as was seen at Barnsley, in 1857, at the Oaks Colliery,
+where both kinds of lamp were in use, and elsewhere.
+
+  [52] _Vide_ "A Description of the Safety-Lamp invented by George
+  Stephenson," etc., London, 1817.
+
+Stephenson continued to study and experiment, with a view to the
+improvement of his locomotive and the railroad. He introduced better
+methods of track-laying and of jointing the rails, adopting a
+half-lap, or peculiar scarf-joint, in place of the then usual
+square-butt joint. He patented, with these modifications of the
+permanent way, several of his improvements of the engine. He had
+substituted forged for the rude cast wheels previously used,[53] and
+had made many minor changes of detail. The engines built at this time
+(1816) continued in use many years. Two years later, with a
+dynamometer which he designed for the purpose, he made experimental
+determinations of the resistance of trains, and showed that it was
+made up of several kinds, as the sliding friction of the axle-journals
+in their bearings, the rolling friction of the wheels on the rails,
+the resistance due to gravity on gradients, and that due to the
+resistance of the air.
+
+  [53] The American chilled wheel of cast-iron, a better wheel than
+  that above described, has never been generally and successfully
+  introduced in Europe.
+
+These experiments seemed to him conclusive against the possibility of
+the competition of engines on the common highway with locomotives
+hauling trains on the rail. Finding that the resistance, with his
+rolling-stock, and at all the speeds at which he made his experiments,
+was approximately invariable, and equivalent to about 10 pounds per
+ton, and estimating that a gradient rising but 1 foot in 100 would
+decrease the hauling power of the engine 50 per cent., he saw at once
+the necessity of making all railroads as nearly absolutely level as
+possible, and, consequently, the radically distinctive character of
+this branch of civil engineering work. He persistently condemned the
+"folly" of attempting the general introduction of steam on the common
+road, where great changes of level and an impressible road-bed were
+certain to prove fatal to success, and was most strenuous in his
+advocacy of the policy of securing level tracks, even at very great
+expense.
+
+Taking part in the contest, which now became a serious one, between
+the advocates of steam on the common road and those urging the
+introduction of locomotives and their trains on an iron track, he
+calculated that a road-engine capable of carrying 20 or 30 passengers
+at 10 miles per hour, could, on the rail, carry ten times as many
+people at three or four times that speed. The railway-engine finally
+superseded its predecessor--the engine of the common road--almost
+completely.
+
+In 1817, Stephenson built an engine for the Duke of Portland, to haul
+coal from Kilmarnock to Troon, which cost L750, and, with some
+interruptions, this engine worked on that line until 1848, when it was
+broken up. On November 18, 1822, the Hetton Railway, near Sunderland,
+was opened. George Stephenson was the engineer of the line--a short
+track, 8 miles long, built from the Hetton Colliery to the docks on
+the bank of the river Wear. On this line he put in five of the
+"self-acting inclines"--two inclines worked by stationary engines, the
+gradients being too heavy for locomotives--and used five
+locomotive-engines of his own design, which were called by the people
+of the neighborhood, possibly for the first time, "the iron horses."
+These engines were quite similar to the Killingworth engine. They drew
+a train of 17 coal-cars--a total load of 64 tons--about 4 miles an
+hour. Meantime, also, in 1823, Stephenson had been made engineer of
+the Stockton & Darlington Railroad, which had been projected for the
+purpose of securing transportation to tide-water for the valuable
+coal-lands of Durham. This road was built without an expectation on
+the part of any of its promoters, Stephenson excepted, that steam
+would be used as a motor to the exclusion of horses.
+
+Mr. Edward Pearse, however, one of the largest holders of stock in the
+road, and one of its most earnest advocates, became so convinced, by
+an examination of the Killingworth engines and their work, of the
+immense advantage to be derived by their use, that he not only
+supported Stephenson's arguments, but, with Thomas Richardson,
+advanced L1,000 for the purpose of assisting Stephenson to commence
+the business of locomotive-engine construction at Newcastle. This
+workshop, which subsequently became a great and famous establishment,
+was commenced in 1824.
+
+For this road Stephenson recommended wrought-iron rails, which were
+then costing L12 per ton--double the price of cast rails. The
+directors, however, stipulated that he should only buy one-half the
+rails required from the dealers in "malleable" iron. These rails
+weighed 20 pounds to the yard. After long hesitation, in the face of a
+serious opposition, the directors finally concluded to order three
+locomotives of Stephenson. The first, or "No. 1," engine (Fig. 52) was
+delivered in time for the opening of the road, September 27, 1825. It
+weighed 8 tons. Its boiler contained a single straight flue, one end
+of which was the furnace. The cylinders were vertical, like those of
+the earlier engines, and coupled directly to the driving-wheels. The
+crank-pins were set in the wheels at right angles, in order that,
+while one engine was "turning the centre," the other might exert its
+maximum power. The two pairs of drivers were coupled by horizontal
+rods, as seen in the figure, which represents this engine as
+subsequently mounted on a pedestal at the Darlington station. A
+steam-blast in the chimney gave the requisite strength of draught.
+These engines were built for slow and heavy work, but were capable of
+making what was then thought the satisfactorily high speed of 16 miles
+per hour. The inclines on the road were worked by fixed engines.
+
+[Illustration: FIG. 52.--Stephenson's No. 1 Engine, 1825.]
+
+On the opening day, which was celebrated as a holiday by the people
+far and near, the No. 1 engine drew 90 tons at the rate of 12, and at
+times 15, miles an hour.
+
+[Illustration: FIG. 58.--Opening of the Stockton and Darlington
+Railroad, 1815. (After an old engraving.)]
+
+Stephenson's engines were kept at work hauling coal-trains, but the
+passenger-coaches were all drawn for some time by horses, and the
+latter system was a rude forerunner, in most respects, of modern
+street-railway transportation. Mixed passenger and freight trains were
+next introduced, and, soon after, separate passenger-trains drawn by
+faster engines were placed on the line, and the present system of
+railroad transportation was now fairly inaugurated.
+
+A railroad between Manchester and Liverpool had been projected at
+about the time that the Stockton & Darlington road was commenced. The
+preliminary surveys had been made in the face of strong opposition,
+which did not always stop at legal action and verbal attack, but in
+some instances led to the display of force. The surveyors were
+sometimes driven from their work by a mob armed with sticks and
+stones, urged on by land-proprietors and those interested in the lines
+of coaches on the highway. Before the opening of the Stockton &
+Darlington Railroad, the Liverpool & Manchester bill had been carried
+through Parliament, after a very determined effort on the part of
+coach-proprietors and landholders to defeat it, and Stephenson urged
+the adoption of the locomotive to the exclusion of horses. It was his
+assertion, made at this time, that he could build a locomotive to run
+20 miles an hour, that provoked the celebrated rejoinder of a writer
+in the _Quarterly Review_, who was, however, in favor of the
+construction of the road and of the use of the locomotive upon it:
+"What can be more palpably absurd and ridiculous, than the prospect
+held out of locomotives traveling _twice as fast_ as stage-coaches? We
+would as soon expect the people of Woolwich to suffer themselves to be
+fired off upon one of Congreve's ricochet-rockets, as trust themselves
+to the mercy of such a machine going at such a rate."
+
+It was during his examination before a committee of the House of
+Commons, during this contest, that Stephenson, when asked, "Suppose,
+now, one of your engines to be going at the rate of 9 or 10 miles an
+hour, and that a cow were to stray upon the line and get in the way
+of the engine, would not that be a very awkward circumstance?"
+replied, "Yes, _very_ awkward--_for the coo!_" And when asked if men
+and animals would not be frightened by the red-hot smoke-pipe,
+answered, "But how would they know that it was not _painted?_" The
+line was finally built, with George Rennie as consulting, and
+Stephenson as principal constructing engineer.
+
+His work on this road became one of the important elements of the
+success, and one of the great causes of the distinction, which marked
+the life of these rising engineers. The successful construction of
+that part of the line which lay across "Chat Moss," an unfathomable
+swampy deposit of peat, extending over an area of 12 square miles, and
+the building of which had been repeatedly declared an impossibility,
+was in itself sufficient to prove that the engineer who had
+accomplished it was no common man. Stephenson adopted the very simple
+yet bold expedient of using, as a filling, compacted turf and peat,
+and building a road-bed of materials lighter than water, or the
+substance composing the bog, and thus forming a _floating_ embankment,
+on which he laid his rails. To the surprise of every one but
+Stephenson himself, the plan proved perfectly successful, and even
+surprisingly economical, costing but little more than one-tenth the
+estimate of at least one engineer. Among the other great works on this
+remarkable pioneer-line were the tunnel, a mile and a half long, from
+the station at Liverpool to Edgehill; the Olive Mount deep-cut, two
+miles long, and in some places 100 feet deep, through red sandstone,
+of which nearly 500,000 yards were removed; the Sankey Viaduct, a
+brick structure of nine arches, of 50 feet span each, costing L45,000;
+and a number of other pieces of work which are noteworthy in even
+these days of great works.
+
+Stephenson planned all details of the line, and even designed the
+bridges, machinery, engines, turn-tables, switches, and crossings,
+and was responsible for every part of the work of their construction.
+
+Finally, the work of building the line approached completion, and it
+became necessary promptly to settle the long-deferred question of a
+method of applying motive-power. Some of the directors and their
+advisers still advocated the use of horses; many thought stationary
+hauling-engines preferable; and the remainder were, almost to a man,
+undecided. The locomotive had no outspoken advocate, and few had the
+slightest faith in it. George Stephenson was almost alone, and the
+opponents of steam had secured a provision in the Newcastle & Carlisle
+Railroad concession, stipulating expressly that horses should there be
+exclusively employed. The directors did, however, in 1828, permit
+Stephenson to put on the line a locomotive, to be used, during its
+construction, in hauling gravel-trains. A committee was sent, at
+Stephenson's request, to see the Stockton & Darlington engines, but no
+decided expression of opinion seems to have been made by them. Two
+well-known professional engineers reported in favor of fixed engines,
+and advised the division of the line into 19 stages of about a mile
+and a half each, and the use of 21 fixed engines, although they
+admitted the excessive first-cost of that system. The board was
+naturally strongly inclined to adopt their plan. Stephenson, however,
+earnestly and persistently opposed such action, and, after long
+debate, it was finally determined "to give the traveling engine a
+chance." The board decided to offer a reward of L500 for the best
+locomotive-engine, and prescribed the following conditions:
+
+  1. The engine must consume its own smoke.
+
+  2. The engine, if of 6 tons weight, must be able to draw after it,
+  day by day, 20 tons weight (including the tender and water-tank) at
+  10 miles an hour, with a pressure of steam on the boiler not
+  exceeding 50 pounds to the square inch.
+
+  3. The boiler must have two safety-valves, neither of which must be
+  fastened down, and one of them completely out of the control of the
+  engine-man.
+
+  4. The engine and boiler must be supported on springs, and rest on 6
+  wheels, the height of the whole not exceeding 15 feet to the top of
+  the chimney.
+
+  5. The engine, with water, must not weigh more than 6 tons; but an
+  engine of less weight would be preferred, on its drawing a
+  proportionate load behind it; if of only 4-1/2 tons, then it might
+  be put only on 4 wheels. The company to be at liberty to test the
+  boiler, etc., by a pressure of 150 pounds to the square inch.
+
+  6. A mercurial gauge must be affixed to the machine, showing the
+  steam-pressure above 45 pounds to the square inch.
+
+  7. The engine must be delivered, complete and ready for trial, at
+  the Liverpool end of the railway, not later than the 1st of October,
+  1829.
+
+  8. The price of the engine must not exceed L550.
+
+This circular was printed and published throughout the kingdom, and a
+considerable number of engines were constructed to compete at the
+trial, which was proposed to take place October 1, 1829, but which was
+deferred to the 6th of that month. Only four engines, however, were
+finally entered on the day of the trial. These were the "Novelty,"
+constructed by Messrs. Braithwaite & Ericsson, the latter being the
+distinguished engineer who subsequently came to the United States to
+introduce screw-propulsion, and, later, the monitor system of
+iron-clads; the "Rocket," built from Stephenson's plans; and the
+"Sanspareil" and the "Perseverance," built by Hackworth and Burstall,
+respectively.
+
+The "Sanspareil," which was built under the direction of Timothy
+Hackworth, one of Stephenson's earlier foremen, resembled the engine
+built by the latter for the Stockton & Darlington road, but was
+heavier than had been stipulated, was not ready for work when called,
+and, when finally set at work, proved to be very extravagant in its
+use of fuel, partly in consequence of the extreme intensity of its
+blast, which caused the expulsion of unconsumed coals from the
+furnace.
+
+The "Perseverance" could not attain the specified speed, and was
+withdrawn.
+
+[Illustration: FIG. 54.--The "Novelty," 1829.]
+
+The "Novelty" was apparently a well-designed and for that time a
+remarkably well-proportioned machine. _A_, in Fig. 54, is the boiler,
+_D_ the steam-cylinders, _E_ a heater. Its weight but slightly
+exceeded three tons, and it was a "tank engine," carrying its own fuel
+and water at _B_. A forced draught was obtained by means of the
+bellows, _C_. This engine was run over the line at the rate of about
+28 miles an hour at times, but its blowing apparatus failed, and the
+"Rocket" held the track alone. A later trial still left the "Rocket"
+alone in the field.
+
+The "Rocket" (Fig. 55) was built at the works of Robert Stephenson &
+Co., at Newcastle-upon-Tyne. The boiler was given considerable
+heating-surface by the introduction of 25 3-inch copper tubes, at the
+suggestion of Henry Booth, secretary of the railroad company. The
+blast was altered by gradually closing in the opening at the extremity
+of the exhaust-pipe, and thus "sharpening" it until it was found to
+have the requisite intensity. The effect of this modification of the
+shape of the pipe was observed carefully by means of syphon
+water-gauges attached to the chimney. The draft was finally given such
+an intensity as to raise the water 3 inches in the tube of the
+draught-gauge. The total length of the boiler was 6 feet, its
+diameter 40 inches. The fire-box was attached to the rear of the
+boiler, and was 3 feet high and 2 feet wide, with water-legs to
+protect its side-sheets from injury by overheating. The cylinders, as
+seen in the sketch, were inclined, and coupled to a single pair of
+driving-wheels. A tender, attached to the engine, carried the fuel and
+water. The engine weighed less than 4-1/2 tons.
+
+[Illustration: FIG. 55.--The "Rocket," 1829.]
+
+The little engine does not seem to have been very prepossessing in
+appearance, and the "Novelty" is said to have been the general
+favorite, the Stephenson engine having few, if any, backers among the
+spectators. On its first trial, it ran 12 miles in less than an hour.
+
+After the accident which disabled the "Novelty," the "Rocket" came
+forward again, and ran at the rate of from 25 to 30 miles an hour,
+drawing a single carriage carrying 30 passengers. Two days later, on
+the 8th of October, steam was raised in a little less than an hour
+from cold water, and it then, with 13 tons of freight in the train,
+ran 35 miles in 1 hour and 48 minutes, including stops, and attained a
+speed of 29 miles an hour. The average of all runs for the trial was
+15 miles an hour.
+
+This success, far exceeding the expectation of the most sanguine of
+the advocates of the system, and greatly exceeding what had been
+asserted by opponents to be the bounds of possibility, settled
+completely the whole question, and the Manchester & Liverpool road was
+at once equipped with locomotive engines.
+
+The "Rocket" remained on the line until 1837, when it was sold, and
+set at work by the purchasers on the Midgeholme Railway, near
+Carlisle. On one occasion, on this road, it was driven 4 miles in
+4-1/2 minutes. It is now in the Patent Museum at South Kensington,
+London.
+
+In January, 1830, a single line of rails had been carried across Chat
+Moss, and, six months later, the first train, drawn by the "Arrow,"
+ran through, June 14th, from Liverpool to Manchester, making the trip
+in an hour and a half, and attaining a maximum speed of over 27 miles
+an hour. The line was formally opened to traffic September 15, 1830.
+
+This was one of the most notable occasions in the history of the
+railroad, and the successful termination of the great work was
+celebrated, as so important an event should be, by impressive
+ceremonies. Among the distinguished spectators were Sir Robert Peel
+and the Duke of Wellington. Mr. Huskisson, a Member of Parliament for
+Liverpool, was also present. There had been built for the line, by
+Robert Stephenson & Co., 7 locomotives besides the "Rocket," and a
+large number of carriages. These were all brought out in procession,
+and 600 passengers entered the train, which started for Manchester,
+and ran at times, on smooth portions of the road, at the rate of 20
+and 25 miles an hour. Crowds of people along the line cheered at this
+strange and to them incomprehensible spectacle, and the story of the
+wonderful performances of that day on the new railroad was repeated in
+every corner of the land. A sad accident, the precursor of thousands
+to follow the introduction of the new method of transportation, while
+it repressed the rising enthusiasm of the people and dampened the
+ardor of the most earnest of the advocates of the railroad, occurring
+during this trip, assisted in making known the power of the new motor
+and the danger attending its use as well. The trains stopped for water
+at Parkside, and occasion was taken to send the "Northumbrian," an
+engine driven by George Stephenson himself, on a side track, with the
+carriage containing the Duke of Wellington, and the other engines and
+trains were all directed to be sent along the main track in view of
+the Duke and his party. While this movement was in process of
+execution, Mr. Huskisson, who had carelessly stood on the main line
+until the "Rocket," which led the column, had nearly reached him,
+attempted to enter the carriage of the Duke. He was too late, and was
+struck by the "Rocket," thrown down across the rail, and the advancing
+engine crushed a leg so seriously that he died the same evening.
+Immediately after the accident, he was placed on the "Northumbrian,"
+and Stephenson made the 15 miles to the destination of the wounded man
+in 25 minutes--a speed of 36 miles an hour. The news of this accident,
+and the statement of the velocity of the engine, were published
+throughout the kingdom and Europe; and the misfortune of this first
+victim of a railroad accident was one of the causes of the immediate
+adoption and rapid spread of the modern railway system.
+
+This road, which was built in the hope of securing 400 passengers per
+day, almost immediately averaged 1,200, and in five years reported
+500,000 passengers for the year.[54] The success of this road insured
+the general introduction of railroads, and from this time forward
+there was never a doubt of their ultimate adoption to the exclusion
+of every other system of general internal communication and
+transportation.
+
+  [54] Smiles.
+
+For some years after this his first great triumph, George Stephenson
+gave his whole time to the building of railroads and the improvement
+of the engine. He was assisted by his son Robert, to whom he gradually
+surrendered his business, and retired to Tapton House, on the Midland
+Railway, and led a busy but pleasant life during the remaining years
+of his existence.
+
+Even as early as 1840, he seems to have projected many improvements
+which were only generally adopted many years later. He proposed
+self-acting and continuous systems of brake, and considered a good
+system of brake of so great importance, that he advocated their
+compulsory introduction by State legislation. He advised moderate
+speeds, from considerations both of safety and of expense.
+
+A few years after the opening of the Liverpool & Manchester road,
+great numbers of schemes were proposed by ignorant or designing men,
+which had for their object the filling of the pockets of their
+proposers rather than the benefit of the stockholders and the public;
+and the Stephensons were often called upon to combat these crude and
+ill-digested plans. Among these was the pneumatic system of
+propulsion, already referred to as first proposed by Papin, in
+combination with his double-acting air-pump, in 1687. It had been
+again proposed in the early part of the present century by Medhurst,
+who proposed a method of pneumatic transmission of small parcels and
+of letters, which is now in use, and, 15 years later, a railroad to
+take the place of that of Stephenson and his coadjutors. The most
+successful of several attempts to introduce this method was that of
+Clegg & Samuda, at West London, and on the London & Croydon road, and
+again in Ireland, between Kingstown and Dalkey. A line of pipe, _B B_,
+seen in Fig. 56, two feet in diameter, was laid between the rails, _A
+A_, of the road. This pipe was fitted with a nicely-packed piston,
+carrying a strong arm, which rose through a slit made along the top of
+the pipe, and covered by a flexible strip of leather, _E E_. This arm
+was attached to the carriage, _C C_, to be propelled. The pressure of
+the atmosphere being removed, by the action of a powerful pump, from
+the side toward which the train was to advance, the pressure of the
+atmosphere on the opposite side drove the piston forward, carrying the
+train with it. Stephenson was convinced, after examining the plans of
+the projectors, that the scheme would fail, and so expressed himself.
+Those who favored it, however, had sufficient influence with
+capitalists to secure repeated trials, although each was followed by
+failure, and it was several years before the last was heard of this
+system.
+
+[Illustration: FIG. 56.--The Atmospheric Railroad.]
+
+A considerable portion of several of the later years of Stephenson's
+life was spent in traveling in Europe, partly on business and partly
+for pleasure. During a visit to Belgium in 1845, he was received
+everywhere, and by all classes, from the king down to the humblest of
+his subjects, with such distinction as is rarely accorded even to the
+greatest men. He soon after visited Spain with Sir Joshua Walmsley, to
+report on a proposed railway from the capital to the Bay of Biscay. On
+this journey he was taken ill, and his health was permanently
+impaired. Thenceforward he devoted himself principally to the
+direction of his own property, which had become very considerable, and
+spent much of his time at the collieries and other works in which he
+had invested it. His son had now entirely relieved him of all business
+connected with railroads, and he had leisure to devote to
+self-improvement and social amusement. Among his friends he claimed
+Sir Robert Peel, his old acquaintance, now Sir William, Fairbairn, Dr.
+Buckland, and many others of the distinguished men of that time.
+
+In August, 1848, Stephenson was attacked with intermittent fever,
+succeeded by haemorrhage from the lungs, and died on the 12th of that
+month, at the age of sixty-six years, honored of all men, and secure
+of an undying fame. Soon after his death, statues were erected at
+Liverpool, London, and Newcastle, the cost of the second of which was
+defrayed by private subscriptions, including a contribution of about
+$1,500 by 3,150 workingmen--one of the finest tributes ever offered to
+the memory of a great man.
+
+But the noblest monument is that which he himself erected by the
+establishment of a system of education and protection of his
+working-people at Clay Cross. He made it a condition of employment
+that every employe should contribute from five to twelve pence each
+fortnight to a fund, to which the works also made liberal
+contributions. From that fund it was directed that the expenses of
+free education of the children of the work-people, night-schools for
+those employed in the works, a reading-room and library, medical
+treatment, and a benevolent fund were to be defrayed. Music and
+cricket-clubs, and prize funds for the best garden, were also founded.
+The school, public hall, and the church of Clay Cross, and this noble
+system of support, are together a nobler monument than any statue or
+similar structure could be.
+
+The character of George Stephenson was in every way admirable. Simple,
+earnest, and honorable; courageous, indomitable, and industrious;
+humorous, kind, and philanthropic, his memory will long be cherished,
+and will long prove an incentive to earnest effort and to the pursuit
+of an honorable fame with hundreds of the youth who, reading his
+simple yet absorbing story, as told by his biographer, shall in later
+years learn to know him.
+
+[Illustration: FIG. 57.--Stephenson's Locomotive, 1833.]
+
+After the death of his father, Robert Stephenson continued, as he had
+already done for several years, to conduct the business of building
+locomotives, as well as of constructing railroads. The work of
+locomotive engine-building was done at Newcastle, and for many years
+those works were the principal engine-building establishment of the
+world.
+
+After their introduction on the Liverpool & Manchester road, the
+engines of the firm of Robert Stephenson & Co. were rapidly modified,
+until they assumed the form shown in Fig. 57, which remained standard
+until their gradual increase in weight compelled the builders to place
+a larger number of wheels beneath them, and make those other changes
+which finally resulted in the creation of distinct types for special
+kinds of work. In the engine of 1833, as shown above, the cylinders,
+_A_, are carried at the extreme forward end of the boiler, and the
+driving-wheels, _B_, are coupled directly to the connecting-rod of the
+engine and to each other. A buffer, _C_, extends in front, and the
+rear end of the boiler is formed into a rectangular fire-box, _D_,
+continuous with the shell, _E_, and the flame and gases pass to the
+connection and smoke-pipe, _F_, _G_, through a large number of small
+tubes, _a_. Steam is led to the cylinders by a steam-pipe, _H H_, to
+which it is admitted by the throttle-valve, _b_. A steam-dome, _I_,
+from which the steam is taken, assists by giving more steam-space far
+above the water-line, and thus furnishing dry steam. The exhaust steam
+issues with great velocity into the chimney from the pipe, _J_, giving
+great intensity of draught. The engine-driver stands on the platform,
+_K_, from which all the valves and handles are accessible. Feed-pumps,
+_L_, supply the boiler with water, which is drawn from the tender
+through the pipes, _e_, _f_.
+
+The valve-gear was then substantially what it is to-day, the
+"Stephenson link" (Fig. 58). On the driving-axle were keyed two
+eccentrics, _E_, so set that the motion of the one was adapted to
+driving the valve when the engine was moving forward, and the other
+was arranged to move the valve when running backward. The former was
+connected, through its strap and the rod, _B_, to the upper end of a
+"strap-link," _A_, while the second was similarly connected with the
+lower end. By means of a handle, _L_, and the link, _n_, and its
+connections, including the counterweighted bell-crank, _M_, this link
+could be raised or depressed, thus bringing the pin on the link-block,
+to which the valve-stem was connected, into action with either
+eccentric. Or, the link being set in mid-gear, the valve would cover
+both steam-ports of the cylinder, and the engine could move neither
+way. As shown, the engine is in position to run backward. A series of
+notches, _Z_, into either of which a catch on _L_ could be dropped,
+enabled the driver to place the link where he chose. In intermediate
+positions, between mid-gear and full-gear, the motion of the valve is
+such as to produce expansion of the steam, and some gain in economy of
+working, although reducing the power of the engine.
+
+[Illustration: FIG. 58.--The Stephenson Valve-Gear, 1833.]
+
+The success of the railroad and the locomotive in Great Britain led to
+its rapid introduction in other countries. In France, as early as
+1823, M. Beaunier was authorized to construct a line of rails from the
+coal-mines of St. Etienne to the Loire, using horses for the traction
+of his trains; and in 1826, MM. Seguin began a road from St. Etienne
+to Lyons. In 1832, engines built at Lyons were substituted for horses
+on these roads, but internal agitations interrupted the progress of
+the new system in France, and, for 10 years after the opening
+of the Manchester & Liverpool road, France remained without
+steam-transportation on land.
+
+In Belgium the introduction of the locomotive was more promptly
+accomplished. Under the direction of Pierre Simon, an enterprising and
+well-informed young engineer, who had become known principally as an
+advocate of the even then familiar project of a canal across the
+Isthmus of Darien, very complete plans of railroad communication for
+the kingdom were prepared, in compliance with a decree dated July 31,
+1834, and were promptly authorized. The road between Brussels and
+Mechlin was opened May 6, 1837, and other roads were soon built; and
+the railway system of Belgium was the first on the Continent of
+Europe.
+
+The first German railroad worked with locomotive steam-engines was
+that between Nuremberg and Fuerth, built under the direction of M.
+Denis. The other European countries soon followed in this rapid march
+of improvement.
+
+In the United States, public attention had been directed to this
+subject, as has already been stated, very early in the present
+century, by Evans and Stevens. At that time the people of the United
+States, as was natural, closely watched every important series of
+events in the mother-country; and so remarkable and striking a change
+as that which was taking place in the time of Stephenson, in methods
+of communication and transportation, could not fail to attract general
+attention and awaken universal interest.
+
+Notwithstanding the success of the early experiments of Evans and
+others, and in spite of the statesmanlike arguments of Stevens and
+Dearborn, and the earnest advocacy of the plan by all who were
+familiar with the revelations which were daily made of the power and
+capabilities of the steam-engine, it was not until after the opening
+of the Manchester & Liverpool road that any action was taken looking
+to the introduction of the locomotive. Colonel John Stevens, in 1825,
+had built a small locomotive, which he had placed on a circular
+railway before his house--now Hudson Terrace--at Hoboken, to prove
+that his statements had a basis of fact. This engine had two "lantern"
+tubular boilers, each composed of small iron tubes, arranged
+vertically in circles about the furnaces.[55] This exhibition had no
+other effect, however, than to create some interest in the subject,
+which aided in securing a rapid adoption of the railroad when once
+introduced.
+
+  [55] One of these sectional boilers is still preserved in the
+  lecture-room of the author, at the Stevens Institute of Technology.
+
+The first line of rails in the New England States is said to have been
+laid down at Quincy, Mass., from the granite quarry to the Neponset
+River, three miles away, in 1826 and 1827. That between the coal-mines
+of Mauch Chunk, Pa., and the river Lehigh, nine miles distant, was
+built in 1827. In the following year the Delaware & Hudson Canal
+Company built a railroad from their mines to the termination of the
+canal at Honesdale. These roads were worked either by gravity or by
+horses and mules.
+
+The competition at Rainhill, on the Liverpool and Manchester Railroad,
+had been so widely advertised, and promised to afford such conclusive
+evidence relative to the value of the locomotive steam-engine and the
+railroad, that engineers and others interested in the subject came
+from all parts of the world to witness the trial. Among the strangers
+present were Mr. Horatio Allen, then chief-engineer of the Delaware &
+Hudson Canal Company, and Mr. E. L. Miller, a resident of Charleston,
+S. C., who went from the United States for the express purpose of
+seeing the new machines tested.
+
+Mr. Allen had been authorized to purchase, for the company with which
+he was connected, three locomotives and the iron for the road, and had
+already shipped one engine to the United States, and had set it at
+work on the road. This engine was received in New York in May, 1829,
+and its trial took place in August at Honesdale, Mr. Allen himself
+driving the engine. But the track proved too light for the locomotive,
+and it was laid up and never set at regular work. This engine was
+called the "Stourbridge Lion"; it was built by Foster, Rastrick & Co.,
+of Stourbridge, England. During the summer of the next year, a small
+experimental engine, which was built in 1829 by Peter Cooper, of New
+York, was successfully tried on the Baltimore & Ohio Railroad, at
+Baltimore, making 13 miles in less than an hour, and moving, at some
+points on the road, at the rate of 18 miles an hour. One carriage
+carrying 36 passengers was attached. This was considered a
+working-model only, and was rated at one horse-power.
+
+Ross Winans, writing of this trial of Cooper's engine, makes a
+comparison with the work done by Stephenson's "Rocket," and claims a
+decided superiority for the former. He concluded that the trial
+established fully the practicability of using locomotives on the
+Baltimore & Ohio road at high speeds, and on all its curves and heavy
+gradients, without inconvenience or danger.
+
+This engine had a vertical tubular boiler, and the draught was urged,
+like that of the "Novelty" at Liverpool, by mechanical means--a
+revolving fan. The single steam-cylinder was 3-1/4 inches in diameter,
+and the stroke of piston 14-1/2 inches. The wheels were 30 inches in
+diameter, and connected to the crank-shaft by gearing. The engine, on
+the trial, worked up to 1.43 horse-power, and drew a gross weight of
+4-1/2 tons. Mr. Cooper, unable to find such tubes as he needed for his
+boiler, used gun-barrels. The whole machine weighed less than a ton.
+
+Messrs. Davis & Gartner, a little later, built the "York" for this
+road--a locomotive having also a vertical boiler, of very similar form
+to the modern steam fire-engine boiler, 51 inches in diameter, and
+containing 282 fire-tubes, 16 inches long, and tapering from 1-1/2
+inches diameter at the bottom to 1-1/4 at the top, where the gases
+were discharged through a combustion-chamber into a steam-chimney.
+This engine weighed 3-1/2 tons.
+
+They subsequently built several "grasshopper" engines (Fig. 59), some
+of which ran many years, doing good work, and one or two of which are
+still in existence. The first--the "Atlantic"--was set at work in
+September, 1832, and hauled 50 tons from Baltimore 40 miles, over
+gradients having a maximum rise of 37 feet to the mile, and on curves
+having a minimum radius of 400 feet, at the rate of 12 to 15 miles an
+hour. This engine weighed 6-1/2 tons, carried 50 pounds of steam--a
+pressure then common on both continents --and burned a ton of
+anthracite coal on the round trip. The blast was secured by a fan, and
+the valve-gear was worked by cams instead of eccentrics. This engine
+made the round trip at a cost of $16, doing the work of 42 horses,
+which had cost $33 per trip. The engine cost $4,500, and was designed
+by Phineas Davis, assisted by Ross Winans.
+
+[Illustration: FIG. 59.--The "Atlantic," 1882.]
+
+Mr. Miller, on his return from the Liverpool & Manchester trial,
+ordered a locomotive for the Charleston & Hamburg Railroad from the
+West Point Foundery. This engine was guaranteed by Mr. Miller to draw
+three times its weight at the rate of 10 miles an hour. It was built
+during the summer of 1830, from the plans of Mr. Miller, and reached
+Charleston in October. The trials were made in November and December.
+
+[Illustration: FIG. 60.--The "Best Friend," 1830.]
+
+This engine (Fig. 60) had a vertical tubular boiler, in which the
+gases rose through a very high fire-box, into which large numbers of
+rods projected from the sides and top, and passed out through tubes
+leading them laterally outward into an outside jacket, through which
+they rose to the chimney. The steam-cylinders were two in number, 8
+inches in diameter and of 16 inches stroke, inclined so as to connect
+with the driving-axle. The four wheels were all of the same size,
+4-1/2 feet in diameter, and connected by coupling-rods. The engine
+weighed 4-1/2 tons. The "Best Friend," as it was called, did excellent
+work until June, 1831, when the explosion of the boiler, in
+consequence of the recklessness of the fireman, unexpectedly closed
+its career.
+
+A second engine (Fig. 61) was built for this road, at the West Point
+Foundery, from plans furnished by Horatio Allen, and was received and
+set at work early in the spring of 1831. The engine, called the "West
+Point," had a horizontal tubular boiler, but was in other respects
+very similar to the "Best Friend." It is said to have done very good
+work.
+
+[Illustration: FIG. 61.--The "West Point," 1831.]
+
+The Mohawk & Hudson Railroad ordered an engine at about this time,
+also, of the West Point Foundery, and the trials, made in July and
+August, 1831, proved thoroughly successful.
+
+This engine, the "De Witt Clinton," was contracted for by John B.
+Jervis, and fitted up by David Matthew. It had two steam-cylinders,
+each 5-1/2 inches in diameter and 16 inches stroke of piston. The
+connecting-rods were directly attached to a cranked axle, and turned
+four coupled wheels 4-1/2 feet in diameter. These wheels had cast-iron
+hubs and wrought-iron spokes and tires. The tubes were of copper,
+2-1/2 inches in diameter and 6 feet long. The engine weighed 3-1/2
+tons, and hauled 5 cars at the rate of 30 miles an hour.
+
+Another engine, the "South Carolina" (Fig. 62), was designed by
+Horatio Allen for the South Carolina Railroad, and completed late in
+the year 1831. This was the first eight-wheeled engine, and the
+prototype, also, of a peculiar and lately-revived form of engine.
+
+In the summer of 1832, an engine built by Messrs. Davis & Gartner, of
+York, Pa., was put on the Baltimore & Ohio road, which at times
+attained a speed, unloaded, of 30 miles an hour. The engine weighed
+3-1/2 tons, and drew, usually, 4 cars, weighing altogether 14 tons,
+from Baltimore to Ellicott's Mills, a distance of 13 miles, in the
+schedule-time, one hour.
+
+[Illustration: FIG. 62.--The "South Carolina," 1831.]
+
+Horatio Allen's engine on the South Carolina Railroad is said to have
+been the first eight-wheeled engine ever built.
+
+It was at about the time of which we are now writing that the first
+locomotive was built of what is now distinctively known as the
+American type--an engine with a "truck" or "bogie" under the forward
+end of the boiler. This was the "American" No. 1, built at the West
+Point Foundery, from plans furnished by John B. Jervis, Chief
+Engineer, for the Mohawk & Hudson Railroad. Ross Winans had already
+(1831) introduced the passenger-car with swiveling trucks.[56] It was
+completed in August, 1832, and is said by Mr. Matthew to have been an
+extremely fast and smooth-running engine. A mile a minute was
+repeatedly attained, and it is stated by the same authority,[57] that
+a speed of 80 miles an hour was sometimes made over a single mile.
+This engine had cylinders 9-1/2 inches diameter, 16 inches stroke of
+piston, two pairs of driving-wheels, coupled, 5 feet in diameter each;
+and the truck had four 33-inch wheels. The boiler contained tubes 3
+inches in diameter, and its fire-box was 5 feet long and 2 feet 10
+inches wide. Robert Stephenson & Co. subsequently built a similar
+engine, from the plans of Mr. Jervis, and for the same road. It was
+set at work in 1833. In both engines the driving-wheels were behind
+the fire-box. This engine is another illustration of the fact--shown
+by the description already given of other and earlier engines--that
+the independence of the American mechanic, and the boldness and
+self-confidence which have to the present time distinguished him, were
+among the earliest of the fruits of our political independence and
+freedom.
+
+  [56] "History of the First Locomotives in America," Brown.
+
+  [57] "Ross Winans _vs._ The Eastern Railroad Company--Evidence."
+  Boston, 1854.
+
+These American engines were all designed to burn anthracite coal. The
+English locomotives all burned bituminous coal.
+
+Robert L. Stevens, the President and Engineer of the Camden & Amboy
+Railroad, and a distinguished son of Colonel John Stevens, of Hoboken,
+was engaged, at the time of the opening of the Liverpool & Manchester
+Railroad, in the construction of the Camden & Amboy Railroad. It was
+here that the first of the now standard form of _T_-rail was laid
+down. It was of malleable iron, and of the form shown in the
+accompanying figure. It was designed by Mr. Stevens, and is known in
+the United States as the "Stevens" rail. In Europe, where it was
+introduced some years afterward, it is sometimes called the
+"Vignolles" rail. He purchased an engine of the Stephensons soon after
+the trial at Rainhill, and this engine, the "John Bull," was set up on
+the then uncompleted road at Bordentown, in the year 1831. Its first
+public trial was made in November of that year. The road was opened
+for traffic, from end to end, two years later. This engine had
+steam-cylinders 9 inches in diameter, 2 feet stroke of piston, one
+pair of drivers 4-1/2 feet in diameter, and weighed 10 tons. This
+engine, and that built by Phineas Davis for the Baltimore & Ohio
+Railroad, were exhibited at the Centennial Exhibition at Philadelphia,
+in the year 1876.
+
+[Illustration: FIG. 63.--The "Stevens" Rail. Enlarged Section.]
+
+[Illustration: FIG. 64.--"Old Ironsides," 1832.]
+
+Engines supplied to the Camden & Amboy Railroad subsequent to 1831
+were built from the designs of Robert L. Stevens, in the shop of the
+Messrs. Stevens, at Hoboken. The other principal roads of the country,
+at first, very generally purchased their engines of the Baldwin
+Locomotive Works, then a small shop owned by Matthias W. Baldwin.
+Baldwin's first engine was a little model built for Peale's Museum, to
+illustrate to the visitors of that then well-known place of
+entertainment the character of the new motor, the success of which,
+at Rainhill, had just then excited the attention of the world. This
+was in 1831, and the successful working of this little model led to
+his receiving an order for an engine from the Philadelphia &
+Germantown Railroad. Mr. Baldwin, after studying the new engine of the
+Camden & Amboy road, made his plans, and built an engine (Fig. 64),
+completing it in the autumn of 1832, and setting it in operation
+November 23d of that year. It was kept at work on that line of road
+for a period of 20 years or more. This engine was of Stephenson's
+"Planet" class, mounted on two driving-wheels 4-1/2 feet in diameter
+each, and two separate wheels of the same size, uncoupled. The
+steam-cylinders were 9-1/2 inches in diameter, 18 inches stroke of
+piston, and were placed horizontally on each side of the smoke-box.
+The boiler, 2-1/2 feet in diameter, contained 72 copper tubes 1-1/2
+inches in diameter and 7 feet long. The engine cost the railroad
+company $3,500. On the trial, steam was raised in 20 minutes, and the
+maximum speed noted was 28 miles an hour. The engine subsequently
+attained a speed of over 30 miles. In 1834, Mr. Baldwin completed for
+Mr. E. L. Miller, of Charleston, a six-wheeled engine, the "E. L.
+Miller" (Fig. 65), with cylinders 10 inches in diameter and 16 inches
+stroke of piston. He made the boiler of this engine of a form which
+remained standard many years, with a high dome over the fire-box. At
+about the same time, he built the "Lancaster," an engine resembling
+the "Miller," for the State road to Columbia, and several others were
+soon contracted for and built. By the end of 1834, 5 engines had been
+built by him, and the construction of locomotive-engines had become
+one of the leading and most promising industries of the United States.
+Mr. William Norris established a shop in Philadelphia in 1832, which
+he gradually enlarged until it, like the Baldwin Works, became a large
+establishment. He usually built a six-wheeled engine, with a
+leading-truck or bogie, and placed his driving-wheels in front of the
+fire-box.
+
+[Illustration: FIG. 65.--The "E. L. Miller," 1834.]
+
+At this time the English locomotives were built to carry 60 pounds of
+steam. The American builders adopted pressures of 120 to 130 pounds
+per square inch, the now generally standard pressures throughout the
+world. In the years 1836 and 1837, Baldwin built 80 engines. They were
+of three classes: 1st, with cylinders 12-1/2 inches in diameter and of
+16 inches stroke, weighing 12 tons; 2d, with cylinders 12 by 16, and
+a weight of 10-1/2 tons; and 3d, engines weighing 9 tons, and having
+steam-cylinders of 10-1/2 inches diameter and of the same stroke. The
+driving-wheels were usually 4-1/2 feet in diameter, and the cylinder
+"inside-connected" to cranked axles. A few "outside-connected" engines
+were made, this plan becoming generally adopted at a later period.
+
+The railroads of the United States were very soon supplied with
+locomotive-engines built in America. In the year 1836, William Norris,
+who had two years before purchased the interest of Colonel Stephen H.
+Long, an army-officer who patented and built locomotives of his own
+design, built the "George Washington," and set it at work. This
+engine, weighing 14,400 pounds, drew 19,200 pounds up an incline 2,800
+feet long, rising 369 feet to the mile, at the speed of 15-1/2 miles
+an hour. This showed an adhesion not far from one-third the weight on
+the driving-wheels. This was considered a very wonderful performance,
+and it produced such an impression at the time, that several copies of
+the "George Washington" were made, on orders from British railroads,
+and the result was the establishment of the reputation of the
+locomotive-engine builders of the United States upon a foundation
+which has never since failed them. The engine had Jervis's
+forward-truck, now always seen under standard engines, which had
+already been placed under railroad-cars by Ross Winans.
+
+In New England, the Locks & Canals Company, of Lowell, began building
+engines as early as 1834, copying the Stephenson engine. Hinckley &
+Drury, of Boston, commenced building an outside-connected engine in
+1840, and their successors, the Boston Locomotive Works, became the
+largest manufacturing establishment of the kind in New England. Two
+years later, Ross Winans, the Baltimore builder, introduced some of
+his engines upon Eastern railroads, fitting them with upright boilers,
+and burning anthracite coal.
+
+The changes which have been outlined produced the now typical American
+locomotive. It was necessarily given such form that it would work
+safely and efficiently on rough, ill-ballasted, and often
+sharply-winding tracks; and thus it soon became evident that the two
+pairs of coupled driving-wheels, carrying two-thirds the weight of the
+whole engine, the forward-truck, and the system of "equalizing"
+suspension-bars, by which the weight is distributed fairly among all
+the wheels, whatever the position of the engine, or whatever the
+irregularity of the track, made it the very best of all known types of
+locomotive for the railroads of a new country. Experience has shown it
+equally excellent on the smoothest and best of roads. The
+"cow-catcher," placed in front to remove obstacles from the track, the
+bell, and the heavy whistle, are characteristics of the American
+engine also. The severity of winter-storms compelled the adoption of
+the "cab," or house, and the use of wood for fuel led to the invention
+of the "spark-arrester" for that class of engines. The heavy grades on
+many roads led to the use of the "sand-box," from which sand was
+sprinkled on the track, to prevent the slipping of the wheels.
+
+In the year 1836, the now standard chilled wheel was introduced for
+cars and trucks; the single eccentric, which had been, until then,
+used on Baldwin engines, was displaced by the double eccentric, with
+hooks in place of the link; and, a year later, the iron frame took the
+place of the previously-used wooden frame on all engines.
+
+The year 1837 introduced a period of great depression in all branches
+of industry, which continued until the year 1840, or later, and
+seriously checked all kinds of manufacturing, including the building
+of locomotives. On the revival of business, numbers of new
+locomotive-works were started, and in these establishments originated
+many new types of engine, each of the more successful of which was
+adapted to some peculiar set of conditions. This variety of type is
+still seen on nearly all of the principal roads.
+
+The direction of change in the construction of locomotive-engines at
+the period at which this division of the subject terminates is very
+well indicated in a letter from Robert Stephenson to Robert L.
+Stevens, dated 1833, which is now preserved at the Stevens Institute
+of Technology. He writes: "I am sorry that the feeling in the United
+States in favor of light railways is so general. In England we are
+making every succeeding railway stronger and more substantial." He
+adds: "Small engines are losing ground, and large ones are daily
+demonstrating that powerful engines are the most economical." He gives
+a sketch of his latest engine, weighing _nine tons_, and capable, as
+he states, of "taking 100 tons, gross load, at the rate of 16 or 17
+miles an hour on a level." To-day there are engines built weighing 70
+tons, and our locomotive-builders have standard sizes guaranteed to
+draw over 2,000 tons on a good and level track.
+
+[Illustration]
+
+
+
+
+CHAPTER V.
+
+_THE MODERN STEAM-ENGINE._
+
+  "Voila la plus merveilleuse de toutes les Machines; le Mecanisme
+  ressemble a celui des animaux. La chaleur est le principe de son
+  mouvement; il se fait dans ses differens tuyaux une circulation,
+  comme celle du sang dans les veines, ayant des valvules qui
+  s'ouvrent et se ferment a propos; elles se nourrit, s'evacue d'elle
+  meme dans les temps regles, et tire de son travail tout ce qu'il lui
+  faut pour subsister. Cette Machine a pris sa naissance en
+  Angleterre, et toutes les Machines a feu qu'on a construites
+  ailleurs que dans la Grande Bretagne ont ete executees par des
+  Anglais."--BELIDOR.
+
+THE SECOND PERIOD OF APPLICATION--1800-1850 (CONTINUED). THE
+STEAM-ENGINE APPLIED TO SHIP-PROPULSION.
+
+
+Among the most obviously important and most inconceivably fruitful of
+all the applications of steam which marked the period we are now
+studying, is that of the steam-engine to the propulsion of vessels.
+This direction of application has been that which has, from the
+earliest period in the history of the steam-engine, attracted the
+attention of the political economist and the historian, as well as the
+mechanician, whenever a new improvement, or the revival of an old
+device, has awakened a faint conception of the possibilities attendant
+upon the introduction of a machine capable of making so great a force
+available. The realization of the hopes, the prophecies, and the
+aspirations of earlier times, in the modern marine steam-engine, may
+be justly regarded as the greatest of all the triumphs of mechanical
+engineering. Although, as has already been stated, attempts were made
+at a very early period to effect this application of steam-power, they
+were not successful, and the steamship is a product of the present
+century. No such attempts were commercially successful until after the
+time of Newcomen and Watt, and at the commencement of the nineteenth
+century. It is, indeed, but a few years since the passage across the
+Atlantic was frequently made in sailing-vessels, and the dangers, the
+discomforts, and the irregularities of their trips were most serious.
+Now, hardly a day passes that does not see several large and powerful
+steamers leaving the ports of New York and Liverpool to make the same
+voyages, and their passages are made with such regularity and safety,
+that travelers can anticipate with confidence the time of their
+arrival at the termination of their voyage to a day, and can cross
+with safety and with comparative comfort even amid the storms of
+winter. Yet all that we to-day see of the extent and the efficiency of
+steam-navigation has been the work of the present century, and it may
+well excite our wonder and our admiration.
+
+The history of this development of the use of steam-power illustrates
+most perfectly that process of growth of this invention which has been
+already referred to; and we can here trace it, step by step, from the
+earliest and rudest devices up to those most recent and most perfect
+designs which represent the most successful existing types of the
+heat-engine--whether considered with reference to its design and
+construction, or as the highest application of known scientific
+principles--that have yet been seen in even the present advanced state
+of the mechanic arts.
+
+The paddle-wheel was used as a substitute for oars at a very early
+date, and a description of paddle-wheels applied to vessels, curiously
+illustrated by a large wood-cut, may be found in the work of Fammelli,
+"De l'artificioses machines," published in old French in 1588.
+Clark[58] quotes from Ogilby's edition of the "Odyssey" a stanza
+which reads like a prophecy, and almost awakens a belief that the
+great poet had a knowledge of steam-vessels in those early times--a
+thousand years before the Christian era. The prince thus addresses
+Ulysses:
+
+  [58] "Steam and the Steam-Engine."
+
+    "We use nor Helm nor Helms-man. Our tall ships
+    Have Souls, and plow with Reason up the deeps;
+    All cities, Countries know, and where they list,
+    Through billows glide, veiled in obscuring Mist;
+    Nor fear they Rocks, nor Dangers on the way."
+
+Pope's translation[59] furnishes the following rendering of Homer's
+prophecy:
+
+  [59] "Odyssey," Book VIII., p. 175.
+
+    "So shalt thou instant reach the realm assigned,
+    In wondrous ships, self-moved, instinct with mind;
+
+    ...
+
+    Though clouds and darkness veil the encumbered sky,
+    Fearless, through darkness and through clouds they fly.
+    Though tempests rage, though rolls the swelling main,
+    The seas may roll, the tempests swell in vain;
+    E'en the stern god that o'er the waves presides,
+    Safe as they pass and safe repass the tide,
+    With fury burns; while, careless, they convey
+    Promiscuous every guest to every bay."
+
+It is stated that the Roman army under Claudius Caudex was taken
+across to Sicily in boats propelled by paddle-wheels turned by oxen.
+Vulturius gives pictures of such vessels.
+
+This application of the force of steam was very possibly anticipated
+600 years ago by Roger Bacon, the learned Franciscan monk, who, in an
+age of ignorance and intellectual torpor, wrote:
+
+"I will now mention some wonderful works of art and nature, in which
+there is nothing of magic, and which magic could not perform.
+Instruments may be made by which the largest ships, with only one man
+guiding them, will be carried with greater velocity than if they were
+full of sailors," etc., etc.
+
+Darwin's poetical prophecy was published long years before Watt's
+engine rendered its partial fulfillment a possibility; and thus, for
+many years before even the first promising effort had been made, the
+minds of the more intelligent had been prepared to appreciate the
+invention when it should finally be brought forward.
+
+The earliest attempt to propel a vessel by steam is claimed by Spanish
+authorities, as has been stated, to have been made by Blasco de Garay,
+in the harbor of Barcelona, Spain, in 1543. The record, claimed as
+having been extracted from the Spanish archives at Simancas, states
+the vessel to have been of 200 tons burden, and to have been moved by
+paddle-wheels; and it is added that the spectators saw, although not
+allowed closely to inspect the apparatus, that one part of it was a
+"vessel of boiling water"; and it is also stated that objection was
+made to the use of this part of the machine, because of the danger of
+explosion.
+
+The account seems somewhat apocryphal, and it certainly led to no
+useful results.
+
+In an anonymous English pamphlet, published in 1651, which is supposed
+by Stuart to have been written by the Marquis of Worcester, an
+indefinite reference to what may probably have been the steam-engine
+is made, and it is there stated to be capable of successful
+application to propelling boats.
+
+In 1690, Papin proposed to use his piston-engine to drive
+paddle-wheels to propel vessels; and in 1707 he applied the
+steam-engine, which he had proposed as a pumping-engine, to driving a
+model boat on the Fulda at Cassel. In this trial he used the
+arrangement of which a sketch has been shown, his pumping-engine
+forcing up water to turn a water-wheel, which, in turn, was made to
+drive the paddles. An account of his experiments is to be found in
+manuscript in the correspondence between Leibnitz and Papin, preserved
+in the Royal Library at Hanover. Professor Joy found there the
+following letter:[60]
+
+  "Dionysius Papin, Councillor and Physician to his Royal Highness the
+  Elector of Cassel, also Professor of Mathematics at Marburg, is
+  about to dispatch a vessel of singular construction down the river
+  Weser to Bremen. As he learns that all ships coming from Cassel, or
+  any point on the Fulda, are not permitted to enter the Weser, but
+  are required to unload at Muenden, and as he anticipates some
+  difficulty, although those vessels have a different object, his own
+  not being intended for freight, he begs most humbly that a gracious
+  order be granted that his ship may be allowed to pass unmolested
+  through the Electoral domain; which petition I most humbly support.
+
+                                                        G. W. LEIBNITZ.
+  "HANOVER, _July 13, 1707_."
+
+This letter was returned to Leibnitz, with the following indorsement:
+
+  "The Electoral Councillors have found serious obstacles in the way of
+  granting the above petition, and, without giving their reasons, have
+  directed me to inform you of their decision, and that, in consequence,
+  the request is not granted by his Electoral Highness.
+
+                                                             H. REICHE.
+  "HANOVER, _July 25, 1707_."
+
+  [60] _Scientific American_, February 24, 1877.
+
+This failure of Papin's petition was the death-blow to his effort to
+establish steam-navigation. A mob of boatmen, who thought they saw in
+the embryo steamship the ruin of their business, attacked the vessel
+at night, and utterly destroyed it. Papin narrowly escaped with his
+life, and fled to England.
+
+In the year 1736, Jonathan Hulls took out an English patent for the
+use of a steam-engine for ship-propulsion, proposing to employ his
+steamboat in towing. In 1737 he published a well-written pamphlet,
+describing this apparatus, which is shown in Fig. 66, a reduced
+fac-simile of the plate accompanying his paper.
+
+[Illustration: FIG. 66.--Hulls's Steamboat, 1736.]
+
+He proposed using the Newcomen engine, fitted with a
+counterpoise-weight and a system of ropes and grooved wheels, which,
+by a peculiar ratchet-like action, gave a continuous rotary motion.
+His vessel was to have been used as a tow-boat. He says, in his
+description: "In some convenient part of the Tow-boat there is placed
+a Vessel about two-3rds full of water, with the Top closed; and this
+Vessel being kept Boiling, rarifies the Water into a Steam, this Steam
+being convey'd thro' a large pipe into a cylindrical Vessel, and there
+condensed, makes a Vacuum, which causes the weight of the atmosphere
+to press down on this Vessel, and so presses down a Piston that is
+fitted into this Cylindrical Vessel, in the same manner as in Mr.
+Newcomen's Engine, with which he raises Water by Fire.
+
+"_P_, the Pipe coming from the Furnace to the Cylinder. _Q_, the
+Cylinder wherein the steam is condensed. _R_, the Valve that stops the
+Steam from coming into the Cylinder, whilst the Steam within the same
+is condensed. _S_, the Pipe to convey the condensing Water into the
+Cylinder. _T_, a cock to let in the condensing Water when the Cylinder
+is full of Steam and the Valve, _P_, is shut. _U_, a Rope fixed to the
+Piston that slides up and down in the Cylinder.
+
+"_Note._ This Rope, _U_, is the same Rope that goes round the wheel,
+_D_, in the machine."
+
+In the large division of his plate, _A_ is the chimney; _B_ is the
+tow-boat; _C C_ is the frame carrying the engine; _Da_, _D_, and _Db_
+are three wheels carrying the ropes _M_, _Fb_, and _Fa_, _M_ being the
+rope _U_ of his smaller figure, 30. _Ha_ and _Hb_ are two wheels on
+the paddle-shafts, _I I_, arranged with pawls so that the
+paddle-wheel, _I I_, always turns the same way, though the wheels _Ha_
+and _Hb_ are given a reciprocating motion; _Fb_ is a rope connecting
+the wheels in the vessel, _Db_, with the wheels at the stern. Hulls
+says:
+
+"When the Weight, _G_, is so raised, while the wheels _Da_, _D_, and
+_Db_ are moving backward, the Rope _Fa_ gives way, and the Power of
+the Weight, _G_, brings the Wheel _Ha_ forward, and the Fans with it,
+so that the Fans always keep going forward, notwithstanding the Wheels
+_Da_, _D_, and _Db_ move backward and forward as the Piston moves up
+and down in the Cylinder. _L L_ are Teeth for a Catch to drop in from
+the Axis, and are so contrived that they catch in an alternate manner,
+to cause the Fan to move always forward, for the Wheel _Ha_, by the
+power of the weight, _G_, is performing his Office while the other
+wheel, _Hb_, goes back in order to fetch another stroke.
+
+"_Note._ The weight, _G_, must contain but half the weight of the
+Pillar of Air pressing on the Piston, because the weight, _G_, is
+raised at the same time as the Wheel _Hb_ performs its Office, so that
+it is in effect two Machines acting alternately, by the weight of one
+Pillar of Air, of such a Diameter as the Diameter of the Cylinder is."
+
+The inventor suggests the use of timber guards to protect the wheels
+from injury, and, in shallow water, the attachment to the
+paddle-shafts of cranks "to strike a Shaft to the Bottom of the River,
+which will drive the Vessel forward with the greater Force." He
+concludes: "Thus I have endeavoured to give a clear and satisfactory
+Account of my New-invented Machine, for carrying Vessels out of and
+into any Port, Harbour, or River, against Wind and Tide, or in a Calm;
+and I doubt not but whoever shall give himself the Trouble to peruse
+this Essay, will be so candid as to excuse or overlook any
+Imperfections in the diction or manner of writing, considering the
+Hand it comes from, if what I have imagined may only appear as plain
+to others as it has done to me, viz., That the Scheme I now offer is
+Practicable, and if encouraged will be Useful."
+
+There is no positive evidence that Hulls ever put his scheme to the
+test of experiment, although tradition does say that he made a model,
+which he tried with such ill success as to prevent his prosecution of
+the experiment further; and doggerel rhymes are still extant which
+were sung by his neighbors in derision of his folly, as they
+considered it.
+
+A prize was awarded by the French Academy of Sciences, in 1752, for
+the best essay on the manner of impelling vessels without wind. It was
+given to Bernouilli, who, in his paper, proposed a set of vanes like
+those of a windmill--a screw, in fact--one to be placed on each side
+of the vessel, and two more behind. For a vessel of 100 tons, he
+proposed a shaft 14 feet long and 2 inches in diameter, carrying
+"eight wheels, for acting on the water, to each of which it" (the
+shaft) "is perpendicular, and forms an axis for them all; the wheels
+should be at equal distances from each other. Each wheel consists of 8
+arms of iron, each 3 feet long, so that the whole diameter of the
+wheel is 6 feet. Each of these arms, at the distance of 20 inches from
+the centre, carries a sheet-iron plane (or paddle) 16 inches square,
+which is inclined so as to form an angle of 60 degrees, both with the
+arbor and keel of the vessel, to which the arbor is placed parallel.
+To sustain this arbor and the wheels, two strong bars of iron, between
+2 and 3 inches thick, proceed from the side of the vessel at right
+angles to it, about 2-1/2 feet below the surface of the water." He
+proposed similar screw-propellers at the stern, and suggested that
+they could be driven by animal or by steam-power.
+
+But a more remarkable essay is quoted by Figuier[61]--the paper of
+l'Abbe Gauthier, published in the "Memoires de la Societe Royale des
+Sciences et Lettres de Nancy." Bernouilli had expressed the belief
+that the best steam-engine then known--that of Newcomen--was not
+superior to some other motors. Gauthier proposed to use that engine in
+the propulsion of paddle-wheels placed at the side of the vessel. His
+plan was not brought into use, but his paper embodied a glowing
+description of the advantages to be secured by its adoption. He states
+that a galley urged by 26 oars on a side made but 4,320 toises (8,420
+meters), or about 5 miles, an hour, and required a crew of 260 men. A
+steam-engine, doing the same work, would be ready for action at all
+times, could be applied, when not driving the vessel, to raising the
+anchor, working the pumps, and to ventilating the ship, while the fire
+would also serve to cook with. The engine would occupy less space and
+weight than the men, would require less aliment, and that of a less
+expensive kind, etc. He would make the boiler safe against explosions
+by bands of iron; would make the fire-box of iron, with a water-filled
+ash-pit and base-plate. His injection-water was to come from the sea,
+and return by a delivery-pipe placed above the water-line. The chains,
+usually leading from the end of the beam to the pump-rods, were to be
+carried around wheels on the paddle-shaft, which were to be provided
+with pawls entering a ratchet, and thus the paddles, having been given
+several revolutions by the descent of the piston and the unwinding of
+the chain, were to revolve freely while the return-stroke was made,
+the chain being hauled down and rewound by the wheel on the shaft, the
+latter being moved by a weight. The engine was proposed to be of 6
+feet stroke, and to make 15 strokes per minute, with a force of 11,000
+pounds.
+
+  [61] "Les Merveilles de la Science."
+
+A little later (1760), a Swiss clergyman, J. A. Genevois, published
+in London a paper relating to the improvement of navigation,[62] in
+which his plan was proposed of compressing springs by steam or other
+power, and applying their effort while recovering their form to
+ship-propulsion.
+
+  [62] "Some New Enquiries tending to the Improvement of Navigation."
+  London, 1760.
+
+It was at this time that the first attempts were made in the United
+States to solve this problem, which had begun to be recognized as one
+of the greatest which had presented itself to the mechanic and the
+engineer.
+
+WILLIAM HENRY was a prominent citizen of the then little village of
+Lancaster, Pa., and was noted as an ingenious and successful
+mechanic.[63] He was still living at the beginning of the present
+century. Mr. Henry was the first to make the "rag" carpet, and was the
+inventor of the screw-auger. He was of a Scotch and North-of-Ireland
+family, his father, John Henry, and his two older brothers, Robert and
+James, having come to the United States about 1720. Robert settled,
+finally, in Virginia, and it is said that Patrick Henry, the patriot
+and orator, was of his family. The others remained in Chester County,
+Pa., where William was born, in 1729. He learned the trade of a
+gunsmith, and, driven from his home during the Indian war (1755 to
+1760), settled in Lancaster.
+
+  [63] _Lancaster Daily Express_, December 10, 1872. This account is
+  collated from various manuscripts and letters in the possession of
+  the author.
+
+In the year 1760 he went to England on business, where his attention
+was attracted to the invention--then new, and the subject of
+discussion in every circle--of James Watt. He saw the possibility of
+its application to navigation and to driving carriages, and, on his
+return home, commenced the construction of a steam-engine, and
+finished it in 1763.
+
+Placing it in a boat fitted with paddle-wheels, he made a trial of the
+new machine on the Conestoga River, near Lancaster, where the craft,
+by some accident, sank,[64] and was lost. He was not discouraged by
+this failure, but made a second model, adding some improvements. Among
+the records of the Pennsylvania Philosophical Society is, or was, a
+design, presented by Henry in 1782, of one of his steamboats. The
+German traveler Schoepff visited the United States in 1783, and at Mr.
+Henry's house, at Lancaster, was shown "a machine by Mr. Henry,
+intended for the propelling of boats, etc.; 'but,' said Mr. Henry, 'I
+am doubtful whether such a machine would find favor with the public,
+as every one considers it impracticable against wind and tide;' but
+that such a Boat _will_ come into use and navigate on the waters of
+the Ohio and Mississippi, he had not the least doubt of, but the time
+had not yet arrived of its being appreciated and applied."
+
+  [64] Bowen's "Sketches," p. 56.
+
+John Fitch, whose experiments will presently be referred to, was an
+acquaintance and frequent visitor to the house of Mr. Henry, and may
+probably have there received the earliest suggestions of the
+importance of this application of steam. About 1777, when Henry was
+engaged in making mathematical and philosophical instruments, and the
+screw-auger, which at that time could only be obtained of him, Robert
+Fulton, then twelve years old, visited him, to study the paintings of
+Benjamin West, who had long been a friend and protege of Henry. He,
+too, not improbably received there the first suggestion which
+afterward led him to desert the art to which he at first devoted
+himself, and which made of the young portrait-painter a successful
+inventor and engineer. West's acquaintance with Henry had no such
+result. The young painter was led by his patron and friend to attempt
+historical pictures,[65] and probably owes his fame greatly to the
+kindly and discerning mechanic. Says Galt, in his "Memoirs of Sir
+Benjamin West" (London, 1816): "Towards his old friend, William Henry,
+of Lancaster City, he always cherished the most grateful affection;
+he was the first who urged him to attempt historical composition."
+
+  [65] Some of West's portraits, including those of Mr. and Mrs.
+  Henry, were lately in the possession of Mr. John Jordan, of
+  Philadelphia.
+
+When, after the invention of Watt, the steam-engine had taken such
+shape that it could really work the propelling apparatus of a paddle
+or screw vessel, a new impetus was given to the work of its
+adaptation. In France, the Marquis de Jouffroy was one of the earliest
+to perceive that the improvements of Watt, rendering the engine more
+compact, more powerful, and, at the same time, more regular and
+positive in its action, had made it, at last, readily applicable to
+the propulsion of vessels. The brothers Perier had imported a Watt
+engine from Soho, and this was attentively studied by the marquis,[66]
+and its application to the paddle-wheels of a steam-vessel seemed to
+him a simple problem. Comte d'Auxiron and Chevalier Charles Mounin, of
+Follenai, friends and companions of Jouffroy, were similarly
+interested, and the three are said to have often discussed the scheme
+together, and to have united in devising methods of applying the new
+motor.
+
+  [66] Figuier.
+
+In the year 1770, D'Auxiron determined to attempt the realization of
+the plans which he had conceived. He resigned his position in the
+army, prepared his plans and drawings, and presented them to M.
+Bertin, the Prime Minister, in the year 1771 or 1772. The Minister was
+favorably impressed, and the King (May 22, 1772) granted D'Auxiron a
+monopoly of the use of steam in river-navigation for 15 years,
+provided he should prove his plans practicable, and they should be so
+adjudged by the Academy.
+
+A company had been formed, the day previous, consisting of D'Auxiron,
+Jouffroy, Comte de Dijon, the Marquis d'Yonne, and Follenai, which
+advanced the requisite funds. The first vessel was commenced in
+December, 1772. When nearly completed, in September, 1774, the boat
+sprung a leak, and, one night, foundered at the wharf. After some
+angry discussion, during which D'Auxiron was rudely, and probably
+unjustly, accused of bad faith, the company declined to advance the
+money needed to recover and complete the vessel. They were, however,
+compelled by the court to furnish it; but, meantime, D'Auxiron died of
+apoplexy, the matter dropped, and the company dissolved. The cost of
+the experiment had been something more than 15,000 francs.
+
+The heirs of D'Auxiron turned the papers of the deceased inventor over
+to Jouffroy, and the King transferred to him the monopoly held by the
+former. Follenai retained all his interest in the project, and the two
+friends soon enlisted a powerful adherent and patron, the Marquis
+Ducrest, a well-known soldier, courtier, and member of the Academy,
+who took an active part in the prosecution of the scheme. M. Jacques
+Perier, the then distinguished mechanic, was consulted, and prepared
+plans, which were adopted in place of those of Jouffroy. The boat was
+built by Perier, and a trial took place in 1774, on the Seine. The
+result was unsatisfactory. The little craft could hardly stem the
+sluggish current of the river, and the failure caused the immediate
+abandonment of the scheme by Perier.
+
+Still undiscouraged, Jouffroy retired to his country home, at
+Baume-les-Dames, on the river Doubs. There he carried on his
+experiments, getting his work done as best he could, with the rude
+tools and insufficient apparatus of a village blacksmith. A Watt
+engine and a chain carrying "duck-foot" paddles were his propelling
+apparatus. The boat, which was about 14 feet long and 6 wide, was
+started in June, 1776. The duck's-foot system of paddles proved
+unsatisfactory, and Jouffroy gave it up, and renewed his experiments
+with a new arrangement. He placed on the paddle-wheel shaft a
+ratchet-wheel, and on the piston-rod of his engine, which was placed
+horizontally in the boat, a double rack, into the upper and the lower
+parts of which the ratchet-wheel geared. Thus the wheels turned in
+the same direction, whichever way the piston was moving. The new
+engine was built at Lyons in 1780, by Messrs. Freres-Jean. The new
+boat was about 140 feet long and 14 feet wide; the wheels were 14 feet
+in diameter, their floats 6 feet long, and the "dip," or depth to
+which they reached, was about 2 feet. The boat drew 3 feet of water,
+and had a total weight of about 150 tons.
+
+At a public trial of the vessel at Lyons, July 15, 1783, the little
+steamer was so successful as to justify the publication of the fact by
+a report and a proclamation. The fact that the experiment was not made
+at Paris was made an excuse on the part of the Academy for withholding
+its indorsement, and on the part of the Government for declining to
+confirm to Jouffroy the guaranteed monopoly. Impoverished and
+discouraged, Jouffroy gave up all hope of prosecuting his plans
+successfully, and reentered the army. Thus France lost an honor which
+was already within her grasp, as she had already lost that of the
+introduction of the steam-engine, in the time of Papin.
+
+About 1785, John Fitch and James Rumsey were engaged in experiments
+having in view the application of steam to navigation.
+
+Rumsey's experiments began in 1774, and in 1786 he succeeded in
+driving a boat at the rate of four miles an hour against the current
+of the Potomac at Shepherdstown, W. Va., in presence of General
+Washington. His method of propulsion has often been reinvented since,
+and its adoption urged with that enthusiasm and persistence which is a
+peculiar characteristic of inventors.
+
+Rumsey employed his engine to drive a great pump which forced a stream
+of water aft, thus propelling the boat forward, as proposed earlier by
+Bernouilli. This same method has been recently tried again by the
+British Admiralty, in a gunboat of moderate size, using a centrifugal
+pump to set in motion the propelling stream, and with some other
+modifications which are decided improvements upon Rumsey's rude
+arrangements, but which have not done much more than his toward the
+introduction of "Hydraulic or Jet Propulsion," as it is now called.
+
+In 1787 he obtained a patent from the State of Virginia for
+steam-navigation. He wrote a treatise "On the Application of Steam,"
+which was printed at Philadelphia, where a Rumsey society was
+organized for the encouragement of attempts at steam-navigation.
+
+Rumsey died of apoplexy, while explaining some of his schemes before a
+London society a short time later, December 23, 1793, at the age of
+fifty years. A boat, then in process of construction from his plans,
+was afterward tried on the Thames, in 1793, and steamed at the rate of
+four miles an hour. The State of Kentucky, in 1839, presented his son
+with a gold medal, commemorative of his father's services "in giving
+to the world the benefit of the steamboat."
+
+JOHN FITCH was an unfortunate and eccentric, but very ingenious,
+Connecticut mechanic. After roaming about until forty years of age, he
+finally settled on the banks of the Delaware, where he built his first
+steamboat.
+
+In April, 1785, as Fitch himself states, at Neshamony, Bucks County,
+Pa., he suddenly conceived the idea that a carriage might be driven by
+steam. After considering the subject a few days, his attention was led
+to the plan of using steam to propel vessels, and from that time to
+the day of his death he was a persistent advocate of the introduction
+of the steamboat. At this time, Fitch says, "I did not know that there
+was a steam-engine on the earth;" and he was somewhat disappointed
+when his friend, the Rev. Mr. Irwin, of Neshamony, showed him a sketch
+of one in "Martin's Philosophy."
+
+Fitch's first model was at once built, and was soon after tried on a
+small stream near Davisville. The machinery was made of brass, and the
+boat was impelled by paddle-wheels. A rough model of his steamboat was
+shown to Dr. John Ewing, Provost of the University of Pennsylvania,
+who, August 20, 1785, addressed a commendatory letter to an ex-Member
+of Congress, William C. Houston, asking him to assist Fitch in
+securing the aid of the General Government. The latter referred the
+inventor, by a letter of recommendation, to a delegate from New
+Jersey, Mr. Lambert Cadwalader. With this, and other letters, Fitch
+proceeded to New York, where Congress then met, and made his
+application in proper form. He was unsuccessful, and equally so in
+attempting to secure aid from the Spanish minister, who desired that
+the profits should be secured, by a monopoly of the invention, to the
+King of Spain. Fitch declined further negotiation, determined that, if
+successful at all, the benefit should accrue to his own countrymen.
+
+In September, 1785, Fitch presented to the American Philosophical
+Society, at Philadelphia, a model in which he had substituted an
+endless chain and floats for the paddle-wheels, with drawings and a
+descriptive account of his scheme. This model is shown in the
+accompanying figure.
+
+[Illustration: FIG. 67.--Fitch's Model, 1785.]
+
+In March, 1786, Fitch was granted a patent by the State of New Jersey,
+for the exclusive right to the navigation of the waters of the State
+by steam, for 14 years. A month later, he was in Philadelphia, seeking
+a similar patent from the State of Pennsylvania. He did not at once
+succeed, but in a few days he had formed a company, raised $300, and
+set about finding a place in which to construct his engine. Henry
+Voight, a Dutch watchmaker, a good mechanic, and a very ingenious man,
+took an interest in the company, and with him Fitch set about his
+work with great enthusiasm. After making a little model, having a
+steam-cylinder but one inch in diameter, they built a model boat and
+engine, the latter having a diameter of cylinder of three inches. They
+tried the endless chain, and other methods of propulsion, without
+success, and finally succeeded with a set of oars worked by the
+engine. In August, 1786, it was determined by the company to authorize
+the construction of a larger vessel; but the money was not readily
+obtained. Meantime, Fitch continued his efforts to secure a patent
+from the State, and was finally, March 28, 1787, successful. He also
+obtained a similar grant from the State of Delaware, in February of
+the same year, and from New York, March 19.
+
+Money was now subscribed more freely, and the work on the boat
+continued uninterruptedly until May, 1787, when a trial was made,
+which revealed many defects in the machinery. The cylinder-heads were
+of wood, and leaked badly; the piston leaked; the condenser was
+imperfect; the valves were not tight. All these defects were remedied,
+and a condenser invented by Voight--the "pipe-condenser"--was
+substituted for that defective detail as previously made.
+
+The steamboat was finally placed in working order, and was found
+capable, on trial, of making three or four miles an hour. But now the
+boiler proved to be too small to furnish steam steadily in sufficient
+quantity to sustain the higher speed. After some delay, and much
+distress on the part of the sanguine inventor, who feared that he
+might be at last defeated when on the very verge of success, the
+necessary changes were finally made, and a trial took place at
+Philadelphia, in presence of the members of the Convention--then in
+session at Philadelphia framing the Federal Constitution--August 22,
+1787. Many of the distinguished spectators gave letters to Fitch
+certifying his success. Fitch now went to Virginia, where he succeeded
+in obtaining a patent, November 7, 1787, and then returned to ask a
+patent of the General Government.
+
+A controversy with Rumsey now followed, in which Fitch asserted his
+claims to the invention of the steamboat, and denied that Rumsey had
+done more than to revive the scheme which Bernouilli, Franklin, Henry,
+Paine, and others, had previously proposed, and that Rumsey's
+_steamboat_ was not made until 1786.
+
+The boiler adopted in Fitch's boat of 1787 was a "pipe-boiler," which
+he had described in a communication to the Philosophical Society, in
+September, 1785. It consisted (Fig. 68) of a small water-pipe, winding
+backward and forward in the furnace, and terminating at one end at the
+point at which the feed-water was introduced, and at the other uniting
+with the steam-pipe leading to the engine. Voight's condenser was
+similarly constructed. Rumsey claimed that this boiler was copied from
+his designs. Fitch brought evidence to prove that Rumsey had not built
+such a boiler until after his own.
+
+[Illustration: FIG. 68.--Fitch and Voight's Boiler, 1787.]
+
+[Illustration: FIG. 69.--Fitch's First Boat, 1787.]
+
+Fitch's first boat-engine had a steam-cylinder 12 inches in diameter.
+A second engine was now built (1788) with a cylinder 18 inches in
+diameter, and a new boat. The first vessel was 45 feet long and 12
+feet wide; the new boat was 60 feet long and of but 8 feet breadth of
+beam. The first boat (Fig. 69) had paddles worked at the sides, with
+the motion given the Indian paddle in propelling a canoe; in the
+second boat (Fig. 70) they were similarly worked, but were placed at
+the stern. There were three of these paddles. The boat was finally
+finished in July, 1788, and made a trip to Burlington, 20 miles from
+Philadelphia. When just reaching their destination, their boiler gave
+out, and they made their return-trip to Philadelphia floating with the
+tide. Subsequently, the boat made a number of excursions on the
+Delaware River, making three or four miles an hour.
+
+[Illustration: FIG. 70.--John Fitch, 1788.]
+
+Another of Fitch's boats, in April, 1790, made seven miles an hour.
+Fitch, writing of this boat, says that "on the 16th of April we got
+our work completed, and tried our boat again; and, although the wind
+blew very fresh at the east, we reigned lord high admirals of the
+Delaware, and no boat on the river could hold way with us." In June
+of that year it was placed as a passenger-boat on a line from
+Philadelphia to Burlington, Bristol, Bordentown, and Trenton,
+occasionally leaving that route to take excursions to Wilmington and
+Chester. During this period, the boat probably ran between 2,000 and
+3,000 miles,[67] and with no serious accident. During the winter of
+1790-'91, Fitch commenced another steamboat, the "Perseverance," and
+gave considerable time to the prosecution of his claim for a patent
+from the United States. The boat was never completed, although he
+received his patent, after a long and spirited contest with other
+claimants, on the 26th of August, 1791, and Fitch lost all hope of
+success. He went to France in 1793, hoping to obtain the privilege of
+building steam-vessels there, but was again disappointed, and worked
+his passage home in the following year.
+
+  [67] "Life of John Fitch," Westcott.
+
+[Illustration: FIG. 71.--John Fitch, 1796.]
+
+In the year 1796, Fitch was again in New York City, experimenting with
+a little _screw_ steamboat on the "Collect" Pond, which then covered
+that part of the city now occupied by the "Tombs," the city prison.
+This little boat was a ship's yawl fitted with a screw, like that
+adopted later by Woodcroft, and driven by a rudely-made engine.
+
+Fitch, while in the city of Philadelphia at about this time, met
+Oliver Evans, and discussed with him the probable future of
+steam-navigation, and proposed to form a company in the West, to
+promote the introduction of steam on the great rivers of that part of
+the country. He settled at last in Kentucky, on his land-grant, and
+there amused himself with a model steamboat, which he placed in a
+small stream near Bardstown. His death occurred there in July, 1798,
+and his body still lies in the village cemetery, with only a rough
+stone to mark the spot.
+
+Both Rumsey and Fitch endeavored to introduce their methods in Great
+Britain; and Fitch, while urging the importance and the advantages of
+his plan, confidently stated his belief that the ocean would soon be
+crossed by steam-vessels, and that the navigation of the Mississippi
+would also become exclusively a steam-navigation. His reiterated
+assertion, "The day will come when some more powerful man will get
+fame and riches from my invention; but no one will believe that poor
+John Fitch can do anything worthy of attention," now almost sounds
+like a prophecy.
+
+During this period, an interest which had never diminished in Great
+Britain had led to the introduction of experimental steamboats in that
+country. PATRICK MILLER, of Dalswinton, had commenced experimenting,
+in 1786-'87, with boats having double or triple hulls, and propelled
+by paddle-wheels placed between the parts of the compound vessel.
+James Taylor, a young man who had been engaged as tutor for Mr.
+Miller's sons, suggested, in 1787, the substitution of steam for the
+manual power which had been, up to that time, relied upon in their
+propulsion. Mr. Miller, in 1787, printed a description of his plan of
+propelling apparatus, and in it stated that he had "reason to believe
+that the power of the Steam-Engine may be applied to work the wheels."
+
+In the winter of 1787-'88, William Symmington, who had planned a new
+form of steam-engine, and made a successful working-model, was
+employed by Mr. Miller to construct an engine for a new boat. This was
+built; the little engine, having two cylinders of but four inches in
+diameter, was placed on board, and a trial was made October 14, 1788.
+The vessel (Fig. 72) was 25 feet long, of 7 feet beam, and made 5
+miles an hour.
+
+[Illustration: FIG. 72.--Miller, Taylor, and Symmington, 1788.]
+
+In the year 1789, a large vessel was built, with an engine having a
+steam-cylinder 18 inches in diameter, and this vessel was ready for
+trial in November of that year. On the first trial, the paddle-wheels
+proved too slight, and broke down; they were replaced by stronger
+wheels, and, in December, the boat, on trial, made seven miles an
+hour.
+
+Miller, like many other inventors, seems to have lost his interest in
+the matter as soon as success seemed assured, and dropped it to take
+up other incomplete plans. More than a quarter of a century later, the
+British Government gave Taylor a pension of L50 per annum, and, in
+1837, his four daughters were each given a similar annuity. Mr.
+Miller received no reward, although he is said to have expended over
+L30,000. The engine of Symmington was condemned by Miller as "the most
+improper of all steam-engines for giving motion to a vessel." Nothing
+more was done in Great Britain until early in the succeeding century.
+
+In the United States, several mechanics were now at work besides
+Fitch. Samuel Morey and Nathan Read were among these. Nicholas
+Roosevelt was another. It had just been found that American mechanics
+were able to do the required shop-work. The first experimental
+steam-engine built in America is stated to have been made in 1773 by
+Christopher Colles, a lecturer before the American Philosophical
+Society at Philadelphia. The first steam-cylinder of any considerable
+size is said[68] to have been made by Sharpe & Curtenius, of New York
+City.
+
+  [68] _Rivington's Gazette_, February 16, 1775.
+
+SAMUEL MOREY was the son of one of the first settlers of Orford, N. H.
+He was naturally fond of science and mechanics, and became something
+of an inventor. He began experimenting with the steamboat in 1790 or
+earlier, building a small vessel, and fitting it with paddle-wheels
+driven by a steam-engine of his own design, and constructed by
+himself.[69] He made a trial-trip one Sunday morning in the summer of
+1790, a friend to accompany him, from Oxford, up the Connecticut
+River, to Fairlee, Vt., a distance of several miles, and returned
+safely. He then went to New York, and spent the summer of each year
+until 1793 in experimenting with his boat and modifications of his
+engine. In 1793 he made a trip to Hartford, returning to New York the
+next summer. His boat was a "stern-wheeler," and is stated to have
+been capable of steaming five miles an hour. He next went to
+Bordentown, N. J., where he built a larger boat, which is said to have
+been a side-wheel boat, and to have worked satisfactorily. His funds
+finally gave out, and he gave up his project after having, in 1797,
+made a trip to Philadelphia. Fulton, Livingston, and Stevens met Morey
+at New York, inspected his boat, and made an excursion to Greenwich
+with him.[70] Livingston is said[71] to have offered to assist Morey
+if he should succeed in attaining a speed of eight miles an hour.
+
+  [69] _Providence Journal_, May 7, 1874. Coll., N. H. Antiquar. Soc.,
+  No. 1; "Who invented the Steamboat?" William A. Mowry, 1874.
+
+  [70] Rev. Cyrus Mann, in the _Boston Recorder_, 1858.
+
+  [71] Westcott.
+
+Morey's experiments seem to have been conducted very quietly, however,
+and almost nothing is known of them. The author has not been able to
+learn any particulars of the engines used by him, and nothing definite
+is known of the dimensions of either boat or machinery. Morey never,
+like Fitch and Rumsey, sought publicity for his plans or notoriety for
+himself.
+
+NATHAN READ, who has already been mentioned, a native of Warren,
+Mass., where he was born in the year 1759, and a graduate of Harvard
+College, was a student of medicine, and subsequently a manufacturer of
+chain-cables and other iron-work for ships. He invented, and in 1798
+patented, a nail-making machine. He was at one time (1800-1803) a
+Member of Congress, and, later, a Justice of the Court of Common
+Pleas, and Chief Justice in Hancock County, Me., after his removal to
+that State in 1807. He died in Belfast, Me., in 1849, at the age of
+ninety years.
+
+In the year 1788 he became interested in the problem of
+steam-navigation, and learned something of the work of Fitch. He first
+attempted to design a boiler that should be strong, light, and
+compact, as well as safe. His first plan was that of the "Portable
+Furnace-Boiler," as he called it; it was patented August 26, 1791. As
+designed, it consisted, as seen in Figs. 73 and 74, which are reduced
+from his patent drawings, of a shell of cylindrical form, like the now
+common vertical tubular boiler. _A_ is the furnace-door, _B_ a heater
+and feed-water reservoir, _D_ a pipe leading the feed-water into the
+boiler,[72] _E_ the smoke-pipe, and _F_ the steam-pipe leading to the
+engine. _G_ is the "shell" of the boiler, and _H_ the fire-box. The
+crown-sheet, _I I_, has depending from it, in the furnace, a set of
+water-tubes, _b b_, closed at their lower ends, and another set, _a
+a_, which connect the water-space above the furnace with the
+water-bottom, _K K_. _L_ is the furnace, and _M_ the draught-space
+between the boiler and the ash-pit, in which the grates are set.
+
+  [72] This is substantially an arrangement that has recently become
+  common. It has been repatented by later inventors.
+
+[Illustration: FIG. 73.--Read's Boiler in Section, 1788.]
+
+[Illustration: FIG. 74.--Read's Multi-Tubular Boiler, 1788.]
+
+This boiler was intended to be used in both steamboats and
+steam-carriages. The first drawings were made in 1788 or 1789, as were
+those of a peculiar form of steam-engine which also resembled very
+closely that afterward constructed in Great Britain by Trevithick.[73]
+He built a boat in 1789, which he fitted with paddle-wheels and a
+crank, which was turned by hand, and, by trial, satisfied himself that
+the system would work satisfactorily.
+
+  [73] "Nathan Read and the Steam-Engine."
+
+He then applied for his patent, and spent the greater part of the
+winter of 1789-'90 in New York, where Congress then met, endeavoring
+to secure it. In January, 1791, Read withdrew his petitions for
+patents, proposing to incorporate accounts of new devices, and renewed
+them a few months later. His patents were finally issued, dated August
+26, 1791. John Fitch, James Rumsey, and John Stevens, also, all
+received patents at the same date, for various methods of applying
+steam to the propulsion of vessels.
+
+Read appears to have never succeeded in even experimentally making his
+plans successful. He deserves credit for his early and intelligent
+perception of the importance of the subject, and for the ingenuity of
+his devices. As the inventor of the vertical multi-tubular fire-box
+boiler, he has also entitled himself to great distinction. This boiler
+is now in very general use, and is a standard form.
+
+In 1792, Elijah Ormsbee, a Rhode Island mechanic, assisted pecuniarily
+by David Wilkinson, built a small steamboat at Winsor's Cove,
+Narragansett Bay, and made a successful trial-trip on the Seekonk
+River. Ormsbee used an "atmospheric engine" and "duck's-foot" paddles.
+His boat attained a speed of from three to four miles an hour.
+
+In Great Britain, Lord Dundas and William Symmington, the former as
+the purveyor of funds and the latter as engineer, followed by Henry
+Bell, were the first to make the introduction of the steam-engine for
+the propulsion of ships so completely successful that no interruption
+subsequently took place in the growth of the new system of
+water-transportation.
+
+Thomas, Lord Dundas, of Kerse, had taken great interest in the
+experiments of Miller, and had hoped to be able to apply the new motor
+on the Forth and Clyde Canal, in which he held a large interest.
+After the failure of the earlier experiments, he did not forget the
+matter; but subsequently, meeting with Symmington, who had been
+Miller's constructing engineer, he engaged him to continue the
+experiments, and furnished all required capital, about L7,000. This
+was ten years after Miller had abandoned his scheme.
+
+Symmington commenced work in 1801. The first boat built for Lord
+Dundas, which has been claimed to have been the "first practical
+steamboat," was finished ready for trial early in 1802. The vessel was
+called the "Charlotte Dundas," in honor of a daughter of Lord Dundas,
+who became Lady Milton.
+
+[Illustration: FIG. 75.--The "Charlotte Dundas," 1801.]
+
+The vessel (Fig. 75) was driven by a Watt double-acting engine,
+turning a crank on the paddle-wheel shaft. The sectional sketch below
+exhibits the arrangement of the machinery. _A_ is the steam-cylinder,
+driving, by means of the connecting-rod, _B C_, a stern-wheel, _E E_.
+_F_ is the boiler, and _G_ the tall smoke-pipe. An air-pump and
+condenser, _H_, is seen under the steam-cylinder.
+
+In March, 1802, the boat was brought to Lock No. 20 on the Forth and
+Clyde Canal, and two vessels of 70 tons burden each taken in tow. Lord
+Dundas, William Symmington, and a party of invited guests, were taken
+on board, and the boat steamed down to Port Glasgow, a distance of
+about 20 miles, against a strong head-wind, in six hours.
+
+The proprietors of the canal were now urged to adopt the new plan of
+towing; but, fearing injury to the banks of the canal, they declined
+to do so. Lord Dundas then laid the matter before the Duke of
+Bridgewater, who gave Symmington an order for eight boats like the
+Charlotte Dundas, to be used on his canal. The death of the Duke,
+however, prevented the contract from being carried into effect, and
+Symmington again gave up the project in despair. A quarter of a
+century later, Symmington received from the British Government L100,
+and, a little later, L50 additional, as an acknowledgment of his
+services. The Charlotte Dundas was laid up, and we hear nothing more
+of that vessel.
+
+[Illustration: FIG. 76.--The "Comet," 1812.]
+
+Among those who saw the Charlotte Dundas, and who appreciated the
+importance of the success achieved by Symmington, was HENRY BELL, who,
+10 years afterward, constructed the Comet (Fig. 76), the first
+passenger-vessel built in Europe. This vessel was built in 1811, and
+completed January 18, 1812. The craft was of 30 tons burden, 40 feet
+in length, and 10-1/2 feet breadth of beam. There were _two_
+paddle-wheels on each side, driven by engines rated at three
+horse-power.
+
+Bell had, it is said, been an enthusiastic believer in the advantages
+to be secured by this application of steam, from about 1786. In 1800,
+and again in 1803, he applied to the British Admiralty for aid in
+securing those advantages by experimentally determining the proper
+form and proportions of machinery and vessel; but was not able to
+convince the Admiralty of "the practicability and great utility of
+applying steam to the propelling of vessels against winds and tides,
+and every obstruction on rivers and seas where there was depth of
+water." He also wrote to the United States Government, urging his
+views in a similar strain.
+
+Bell's boat was, when finished, advertised as a passenger-boat, to
+leave Greenock, where the vessel was built, on Mondays, Wednesdays,
+and Fridays, for Glasgow, 24 miles distant, returning Tuesdays,
+Thursdays, and Saturdays. The fare was made "four shillings for the
+best cabin, and three shillings for the second." It was some months
+before the vessel became considered a trustworthy means of conveyance.
+Bell, on the whole, was at first a heavy loser by his venture,
+although his boat proved itself a safe, stanch vessel.
+
+Bell constructed several other boats in 1815, and with his success
+steam-navigation in Great Britain was fairly inaugurated. In 1814
+there were five steamers, all Scotch, regularly working in British
+waters; in 1820 there were 34, one-half of which were in England, 14
+in Scotland, and the remainder in Ireland. Twenty years later, at the
+close of the period to which this chapter is especially devoted, there
+were about 1,325 steam-vessels in that kingdom, of which 1,000 were
+English and 250 Scotch.
+
+But we must return to America, to witness the first and most complete
+success, commercially, in the introduction of the steamboat.
+
+The Messrs. Stevens, Livingston, Fulton, and Roosevelt were there the
+most successful pioneers. The latter is said to have built the
+"Polacca," a small steamboat launched on the Passaic River in 1798.
+The vessel was 60 feet long, and had an engine of 20 inches diameter
+of cylinder and 2 feet stroke, which drove the boat 8 miles an hour,
+carrying a party of invited guests, which included the Spanish
+Minister. Livingston and John Stevens had induced Roosevelt to try
+their plans still earlier,[74] paying the expense of the experiments.
+The former adopted the plan of Bernouilli and Rumsey, using a
+centrifugal pump to force a jet of water from the stern; the latter
+used the screw. Livingston going to France as United States Minister,
+Barlow carried over the plans of the "Polacca," and Roosevelt's
+friends state that a boat built by them, in conjunction with Fulton,
+was a "sister-ship" to that vessel. In 1798, Roosevelt patented a
+double engine, having cranks set at right angles. As late as 1814 he
+received a patent for a steam-vessel, fitted with paddle-wheels having
+adjustable floats. His boat of 1798 is stated by some writers to have
+been made by him on joint account of himself, Livingston, and Stevens.
+Roosevelt, some years later, was again at work, associating himself
+with Fulton in the introduction of steam-navigation of the rivers of
+the West.[75]
+
+  [74] "Encyclopaedia Americana."
+
+  [75] "A Lost Chapter in the History of the Steamboat," J. H. B.
+  Latrobe, 1871.
+
+In 1798, the Legislature of New York passed a law giving Chancellor
+Livingston the exclusive right to steam-navigation in the waters of
+the State for a period of 20 years, _provided_ that he should succeed,
+within a twelve-month, in producing a boat that should steam four
+miles an hour.
+
+Livingston did not succeed in complying with the terms of the act,
+but, in 1803, he procured the reenactment of the law in favor of
+himself and Robert Fulton, who was then experimenting in France, after
+having, in England, watched the progress of steam-navigation there,
+and then taken a patent in this country.
+
+[Illustration: Robert Fulton.]
+
+ROBERT FULTON was a native of Little Britain, Lancaster County, Pa.,
+born 1765. He commenced experimenting with paddle-wheels when a mere
+boy, in 1779, visiting an aunt living on the bank of the
+Conestoga.[76] During his youth he spent much of his time in the
+workshops of his neighborhood, and learned the trade of a watchmaker;
+but he adopted, finally, the profession of an artist, and exhibited
+great skill in portrait-painting. While his tastes were at this time
+taking a decided bent, he is said to have visited frequently the house
+of William Henry, already mentioned, to see the paintings of Benjamin
+West, who in his youth had been a kind of protege of Mr. Henry; and he
+may probably have seen there the model steamboats which Mr. Henry
+exhibited, in 1783 or 1784, to the German traveler Schoepff. In later
+years, Thomas Paine, the author of "Common Sense," at one time lived
+with Mr. Henry, and afterward, in 1788, proposed that Congress take up
+the subject for the benefit of the country.
+
+  [76] _Vide_ "Life of Fulton," Reigart.
+
+Fulton went to England when he came of age, and studied painting with
+Benjamin West. He afterward spent two years in Devonshire, where he
+met the Duke of Bridgewater, who afterward so promptly took advantage
+of the success of the "Charlotte Dundas."
+
+While in England and in France--where he went in 1797, and resided
+some time--he may have seen something of the attempts which were
+beginning to be made to introduce steam-navigation in both of those
+countries.
+
+At about this time--perhaps in 1793--Fulton gave up painting as a
+profession, and became a civil engineer. In 1797 he went to Paris, and
+commenced experimenting with submarine torpedoes and torpedo-boats. In
+1801 he had succeeded so well with them as to create much anxiety in
+the minds of the English, then at war with France.
+
+He had, as early as 1793, proposed plans for steam-vessels, both to
+the United States and the British Governments, and seems never
+entirely to have lost sight of the subject.[77] While in France he
+lived with Joel Barlow, who subsequently became known as a poet, and
+as Embassador to France from the United States, but who was then
+engaged in business in Paris.
+
+  [77] _Vide_ "Life of Fulton," Colden.
+
+When about leaving the country, Fulton met Robert Livingston
+(Chancellor Livingston, as he is often called), who was then (1801)
+Embassador of the United States at the court of France. Together they
+discussed the project of applying steam to navigation, and determined
+to attempt the construction of a steamboat on the Seine; and in the
+early spring of the year 1802, Fulton having attended Mrs. Barlow to
+Plombieres, where she had been sent by her physician, he there made
+drawings and models, which were sent or described to Livingston. In
+the following winter Fulton completed a model side-wheel boat.
+
+[Illustration: FIG. 77.--Fulton's Experiments.]
+
+January 24, 1803, he delivered this model to MM. Molar, Bordel, and
+Montgolfier, with a descriptive memoir, in which he stated that he
+had, by experiment, proven that side-wheels were better than the
+"chaplet" (paddle-floats set on an endless chain).[78] These gentlemen
+were then building for Fulton and Livingston their first boat, on
+L'Isle des Cygnes, in the Seine. In planning this boat, Fulton had
+devised many different methods of applying steam to its propulsion,
+and had made some experiments to determine the resistance of fluids.
+He therefore had been able to calculate, more accurately than had any
+earlier inventor, the relative size and proportions of boat and
+machinery.
+
+  [78] A French inventor, a watchmaker of Trevoux, named Desblancs,
+  had already deposited at the Conservatoire a model fitted with
+  "chaplets."
+
+[Illustration: FIG. 78.--Fulton's Table of Resistances.]
+
+The author has examined a large collection of Fulton's drawings, among
+which are sketches, very neatly executed, of many of these plans,
+including the chaplet, side-wheel, and stern-wheel boats, driven by
+various forms of steam-engine, some working direct, and some geared to
+the paddle-wheel shaft. Figs. 77 and 78 are engraved from two of these
+sheets. The first represents the method adopted by Fulton to determine
+the resistance of masses of wood of various forms and proportions,
+when towed through water. The other is "A Table of the resistance of
+bodies moved through water, taken from experiments made in England by
+a society for improving Naval architecture, between the years 1793 and
+1798" (Fig. 78). This latter is from a certified copy of "The Original
+Drawing on file in the Office of the Clerk of the New York District,
+making a part of the Demonstration of the patent granted to Robert
+Fulton, Esqr., on the 11th day of February, 1809. Dated this 3rd
+March, 1814," and is signed by Theron Rudd, Clerk of the New York
+District. Resistances are given in pounds per square foot.
+
+Guided by these experiments and calculations, therefore, Fulton
+directed the construction of his vessel. It was completed in the
+spring of 1803. But, unfortunately, the hull of the little vessel was
+too weak for its heavy machinery, and it broke in two and sank to the
+bottom of the Seine. Undiscouraged, Fulton at once set about repairing
+damages. He was compelled to direct the rebuilding of the hull. The
+machinery was little injured. In June, 1803, the reconstruction was
+completed, and the vessel was set afloat in July. The hull was 66 feet
+long, of 8 feet beam, and of light draught.
+
+August 9, 1803, this boat was cast loose, and steamed up the Seine, in
+presence of an immense concourse of spectators. A committee of the
+National Academy, consisting of Bougainville, Bossuet, Carnot, and
+Perier, were present to witness the experiment. The boat moved but
+slowly, making only between 3 and 4 miles an hour against the current,
+the speed through the water being about 4-1/2 miles; but this was, all
+things considered, a great success.
+
+The experiment was successful, but it attracted little attention,
+notwithstanding the fact that its success had been witnessed by the
+committee of the Academy and by many well-known savants and mechanics,
+and by officers on Napoleon's staff. The boat remained a long time on
+the Seine, near the palace. The water-tube boiler of this vessel (Fig.
+79) is still preserved at the Conservatoire des Arts et Metiers at
+Paris, where it is known as Barlow's boiler. Barlow patented it in
+France as early as 1793, as a steamboat-boiler, and states that the
+object of his construction was to obtain the greatest possible extent
+of heating-surface.
+
+Fulton endeavored to secure the pecuniary aid and the countenance of
+the First Consul, but in vain.
+
+Livingston wrote home, describing the trial of this steamboat and its
+results, and procured the passage of an act by the Legislature of the
+State of New York, extending a monopoly granted him in 1798 for the
+term of 20 years from April 5, 1803, the date of the new law, and
+extending the time allowed for proving the practicability of driving a
+boat four miles an hour by steam to two years from the same date. A
+later act further extended the time to April, 1807.
+
+[Illustration: FIG. 79.--Barlow's Water-Tube Boiler, 1793.]
+
+In May, 1804, Fulton went to England, giving up all hope of success in
+France with either his steamboats or his torpedoes. Fulton had already
+written to Boulton & Watt, ordering an engine to be built from plans
+which he furnished them; but he had not informed them of the purpose
+to which it was to be applied. This engine was to have a
+steam-cylinder 2 feet in diameter and of 4 feet stroke. The engine of
+the Charlotte Dundas was of very nearly the same size; and this fact,
+and the visit of Fulton to Symmington in 1801, as described by the
+latter, have been made the basis of a claim that Fulton was a copyist
+of the plans of others. The general accordance of the dimensions of
+his boat on the Seine with those of the "Polacca" of Roosevelt is also
+made the basis of similar claims by the friends of the latter. It
+would appear, however, that Symmington's statement is incorrect, as
+Fulton was in France, experimenting with torpedoes, at the time (July,
+1801[79]) when he is accused of having obtained from the English
+engineer the dimensions and a statement of the performance of his
+vessel. Yet a fireman employed by Symmington has made an affidavit to
+the same statement. It is evident, however, from what has preceded,
+that those inventors and builders who were at that time working with
+the object of introducing the steamboat were usually well acquainted
+with what had been done by others, and with what was being done by
+their contemporaries; and it is undoubtedly the fact that each
+profited, so far as he was able, by the experience of others.
+
+  [79] Woodcroft, p. 64.
+
+While in England, however, Fulton was certainly not so entirely
+absorbed in the torpedo experiments with which he was occupied in the
+years 1804-'6 as to forget his plans for a steamboat; and he saw the
+engine ordered by him in 1804 completed in the latter year, and
+preceded it to New York, sailing from Falmouth in October, 1806, and
+reaching the United States December 13, 1806.
+
+The engine was soon received, and Fulton immediately contracted for a
+hull in which to set it up. Meantime, Livingston had also returned to
+the United States, and the two enthusiasts worked together on a larger
+steamer than any which had yet been constructed.
+
+In the spring of 1807, the "Clermont" (Fig. 80), as the new boat was
+christened, was launched from the ship-yard of Charles Brown, on the
+East River, New York. In August the machinery was on board and in
+successful operation. The hull of this boat was 133 feet long, 18
+wide, and 9 deep. The boat soon made a trip to Albany, running the
+distance of 150 miles in 32 hours running time, and returning in 30
+hours. The sails were not used on either occasion.
+
+[Illustration: FIG. 80.--The Clermont, 1807.]
+
+This was the first voyage of considerable length ever made by a
+steam-vessel; and Fulton, though not to be classed with James Watt as
+an inventor, is entitled to the great honor of having been the first
+to make steam-navigation an every-day commercial success, and of
+having thus made the first application of the steam-engine to
+ship-propulsion, which was not followed by the retirement of the
+experimenter from the field of his labors before success was
+permanently insured.
+
+[Illustration: FIG. 81.--Engine of the Clermont, 1808.]
+
+The engine of the Clermont (Fig. 81) was of rather peculiar form, the
+piston, _E_, being coupled to the crank-shaft, _O_, by a bell-crank,
+_I H P_, and a connecting-rod, _P Q_, the paddle-wheel shaft, _M N_,
+being separate from the crank-shaft, and connected with the latter by
+gearing, _O O_. The cylinders were 24 inches in diameter by 4 feet
+stroke. The paddle-wheels had buckets 4 feet long, with a dip of 2
+feet. Old drawings, made by Fulton's own hand, and showing the engine
+as it was in 1808, and the engine of a later steamer, the Chancellor
+Livingston, are in the lecture-room of the author at the Stevens
+Institute of Technology.
+
+The voyage of the Clermont to Albany was attended by some ludicrous
+incidents, which found their counterparts wherever, subsequently,
+steamers were for the first time introduced. Mr. Colden, the
+biographer of Fulton, says that she was described, by persons who had
+seen her passing by night, "as a monster moving on the waters, defying
+wind and tide, and breathing flames and smoke."
+
+This first steamboat used dry pine wood for fuel, and the flames rose
+to a considerable distance above the smoke-pipe. When the fires were
+disturbed, mingled smoke and sparks would rise high in the air. "This
+uncommon light," says Colden, "first attracted the attention of the
+crews of other vessels. Notwithstanding the wind and tide were averse
+to its approach, they saw with astonishment that it was rapidly coming
+toward them; and when it came so near that the noise of the machinery
+and paddles was heard, the crews (if what was said in the newspapers
+of the time be true), in some instances, shrank beneath their decks
+from the terrific sight, and left their vessels to go on shore; while
+others prostrated themselves, and besought Providence to protect them
+from the approach of the horrible monster which was marching on the
+tides, and lighting its path by the fires which it vomited."
+
+In the Clermont, Fulton used several of the now characteristic
+features of the American river steamboat, and subsequently introduced
+others. His most important and creditable work, aside from that of
+the introduction of the steamboat into every-day use, was the
+experimental determination of the magnitude and the laws of
+ship-resistance, and the systematic proportioning of vessel and
+machinery to the work to be done by them.
+
+The success of the Clermont on the trial-trip was such that Fulton
+soon after advertised the vessel as a regular passenger-boat between
+New York and Albany.[80]
+
+  [80] A newspaper-slip in the scrap-book of the author has the
+  following:
+
+  "The traveler of today, as he goes on board the great steamboats St.
+  John or Drew, can scarcely imagine the difference between such
+  floating palaces and the wee-bit punts on which our fathers were
+  wafted 60 years ago. We may, however, get some idea of the sort of
+  thing then in use by a perusal of the steamboat announcements of
+  that time, two of which are as follows:
+
+  ["_Copy of an Advertisement taken from the Albany Gazette, dated
+  September, 1807._]
+
+  "The North River Steamboat will leave Pauler's Hook Ferry [now
+  Jersey City] on Friday, the 4th of September, at 9 in the morning,
+  and arrive at Albany on Saturday, at 9 in the afternoon. Provisions,
+  good berths, and accommodations are provided.
+
+  "The charge to each passenger is as follows:
+
+  "To Newburg        dols. 3,    time 14 hours.
+   "  Poughkeepsie     "   4,      "  17   "
+   "  Esopus           "   5,      "  20   "
+   "  Hudson           "   5-1/2,  "  30   "
+   "  Albany           "   7,      "  36   "
+
+  "For places, apply to William Vandervoort, No. 48 Courtlandt Street,
+  on the corner of Greenwich Street.
+
+  "_September 2, 1807._
+
+  ["_Extract from the New York Evening Post, dated October 2, 1807._]
+
+  "Mr. Fulton's new-invented _Steamboat_, which is fitted up in a neat
+  style for passengers, and is intended to run from New York to Albany
+  as a Packet, left here this morning with 90 passengers, against a
+  strong head-wind. Notwithstanding which, it was judged she moved
+  through the waters at the rate of six miles an hour."
+
+During the next winter the Clermont was repaired and enlarged, and in
+the summer of 1808 was again on the route to Albany; and, meantime,
+two new steamboats--the Raritan and the Car of Neptune--had been built
+by Fulton. In the year 1811 he built the Paragon. Both of the two
+vessels last named were of nearly double the size of the Clermont. A
+steam ferry-boat was built to ply between New York and Jersey City in
+1812, and the next year two others, to connect the metropolis with
+Brooklyn. These were "twin-boats," the two parallel hulls being
+connected by a "bridge" or deck common to both. The Jersey ferry was
+crossed in fifteen minutes, the distance being a mile and a half.
+To-day, the time occupied at the same ferry is about ten minutes.
+Fulton's ferry-boat carried, at one load, 8 carriages, and about 30
+horses, and still had room for 300 or 400 foot-passengers. Fulton also
+designed steam-vessels for use on the Western rivers, and, in 1815,
+some of his boats were started as "packets" on the line between New
+York and Providence, R. I.
+
+Meantime, the War of 1812 was in progress, and Fulton designed a steam
+vessel-of-war, which was then considered a wonderfully formidable
+craft. His plans were submitted to a commission of experienced naval
+officers, among whom were Commodores Decatur and Perry, Captain John
+Paul Jones, Captain Evans, and others whose names are still familiar,
+and were favorably commended. Fulton proposed to build a steam-vessel
+capable of carrying a heavy battery, and of steaming four miles an
+hour. The ship was to be fitted with furnaces for red-hot shot. Some
+of her guns were to be discharged below the water-line. The estimated
+cost was $320,000.
+
+The construction of the vessel was authorized by Congress in March,
+1814; the keel was laid June 20, 1814, and the vessel was launched
+October 29th of the same year.
+
+[Illustration: FIG. 82.--Launch of the "Fulton the First," 1804.]
+
+The "Fulton the First," as she was called, was considered an enormous
+vessel at that time. The hull was double, 156 feet long, 56 feet wide,
+and 20 feet deep, measuring 2,475 tons. In the following May the ship
+was ready for her engine, and in July was so far completed as to
+steam, on a trial-trip, to the ocean at Sandy Hook and back--53
+miles--in 8 hours and 20 minutes. In September of the same year, with
+armament and stores on board, the same route was traversed again, the
+vessel making 5-1/2 miles an hour. The vessel, as thus completed, had
+a double hull, each about 20 feet longer than the Clermont, and
+separated by a space 15 feet across. Her engine, having a
+steam-cylinder 48 inches in diameter and of 5 feet stroke of piston,
+was furnished with steam by a copper boiler 22 feet long, 12 feet
+wide, and 8 feet high, and turned a wheel between the two hulls which
+was 16 feet in diameter, and carried "floats" or "buckets" 14 feet
+long, and with a dip of 4 feet. The engine was in one of the two
+hulls, and the boiler in the other. The sides, at the gun-deck, were 4
+feet 10 inches thick, and her spar-deck was surrounded by heavy
+musket-proof bulwarks. The armament consisted of 30 32-pounders, which
+were intended to discharge red-hot shot. There was one heavy mast for
+each hull, fitted with large latteen sails. Each end of each hull was
+fitted with a rudder. Large pumps were carried, which were intended to
+throw heavy streams of water upon the decks of the enemy, with a view
+to disabling the foe by wetting his ordnance and ammunition. A
+submarine gun was to have been carried at each bow, to discharge shot
+weighing 100 pounds, at a depth of 10 feet below the water-line.
+
+This was the first application of the steam-engine to naval purposes,
+and, for the time, it was an exceedingly creditable one. Fulton,
+however, did not live to see the ship completed. He was engaged in a
+contest with Livingston, who was then endeavoring to obtain permission
+from the State of New Jersey to operate a line of steamboats in the
+waters of the Hudson River and New York Bay, and, while returning from
+attending a session of the Legislature at Trenton, in January, 1815,
+was exposed to the weather on the bay at a time when he was ill
+prepared to withstand it. He was taken ill, and died February 24th of
+that year. His death was mourned as a national calamity.
+
+From the above brief sketch of this distinguished man and his work, it
+is seen that, although Robert Fulton is not entitled to distinction as
+an inventor, he was one of the ablest, most persistent, and most
+successful of those who have done so much for the world by the
+introduction of the inventions of others. He was an intelligent
+engineer and an enterprising business-man, whose skill, acuteness, and
+energy have given the world the fruits of the inventive genius of all
+who preceded him, and have thus justly earned for him a fame that can
+never be lost.
+
+Fulton had some active and enterprising rivals.
+
+Oliver Evans had, in 1801 or 1802, sent one of his engines, of about
+150 horse-power, to New Orleans, for the purpose of using it to propel
+a vessel owned by Messrs. McKeever and Valcourt, which was there
+awaiting it. The engine was actually set up in the boat, but at a low
+stage of the river, and no trial could be made until the river should
+again rise, some months later. Having no funds to carry them through
+so long a period, Evans's agents were induced to remove the engine
+again, and to set it up in a saw-mill, where it created great
+astonishment by its extraordinary performance in sawing lumber.
+
+Livingston and Roosevelt were also engaged in experiments quite as
+early as Fulton, and perhaps earlier.
+
+The prize gained by Fulton was, however, most closely contested by
+Colonel JOHN STEVENS, of Hoboken, who has been already mentioned in
+connection with the early history of railroads, and who had been since
+1791 engaged in similar experiments. In 1789 he had petitioned the
+Legislature of the State of New York for a grant similar to that
+accorded to Livingston, and he then stated that his plans were
+complete, and on paper.
+
+[Illustration: FIG. 83.--Section of Steam-Boiler, 1804.]
+
+In 1804, while Fulton was in Europe, Stevens had completed a
+steamboat, 68 feet long and of 14 feet beam, which combined novelties
+and merits of design in a manner that exhibited the best possible
+evidence of remarkable inventive talent, as well as of the most
+perfect appreciation of the nature of the problem which he had
+proposed to himself to solve. Its boiler (Fig. 83) was of what is now
+known as the water-tubular variety. It was quite similar to some now
+known as sectional boilers, and contained 100 tubes 2 inches in
+diameter and 18 inches long, each fastened at one end to a central
+water-leg and steam-drum, and plugged at the other end. The flames
+from the furnace passed around and among the tubes, the water being
+inside them. The engine (Fig. 84) was a _direct-acting high-pressure_
+condensing engine, having a 10-inch cylinder, 2 feet stroke of piston,
+and drove a _screw_ having four blades, and of a form which, even
+to-day, appears quite good. The whole is a most remarkable piece of
+early engineering.
+
+[Illustration: FIG. 84.--Engine, Boiler, and Screw-Propellers used by
+Stevens, 1804.]
+
+A model of this little steamer, built in 1804, is preserved in the
+lecture-room of the Department of Mechanical Engineering at the
+Stevens Institute of Technology; and the machinery itself, consisting
+of the high-pressure "sectional" or "safety" tubular boiler, as it
+would be called to-day, the high-pressure condensing engine, with
+rotating valves, and twin screw-propellers, as just described, is
+given a place of honor in the model-room, or museum, where it
+contrasts singularly with the mechanism contributed to the collection
+by manufacturers and inventors of our own time. The hub and blade of a
+single screw, also used with the same machinery, is likewise to be
+seen there.
+
+[Illustration: FIG. 85.--Stevens's Screw Steamer, 1804.]
+
+Stevens seems to have been the first to fully recognize the importance
+of the principle involved in the construction of the sectional
+steam-boiler. His eldest son, John Cox Stevens, was in Great Britain
+in the year 1805, and, while there, patented another modification of
+this type of boiler. In his specification, he details both the method
+of construction and the principles which determine its form. He says
+that he describes this invention as it was made known to him by his
+father, and adds:
+
+"From a series of experiments made in France, in 1790, by M. Belamour,
+under the auspices of the Royal Academy of Sciences, it has been found
+that, within a certain range the elasticity of steam is nearly doubled
+by every addition of temperature equal to 30 deg. of Fahrenheit's
+thermometer. These experiments were carried no higher than 280 deg., at
+which temperature the elasticity of steam was found equal to about
+four times the pressure of the atmosphere. By experiments which have
+lately been made by myself, the elasticity of steam at the temperature
+of boiling oil, which has been estimated at about 600 deg., was found to
+equal 40 times the pressure of the atmosphere.
+
+"To the discovery of this principle or law, which obtains when water
+assumes a state of vapor, I certainly can lay no claim; but to the
+application of it, upon certain principles, to the improvement of the
+steam-engine, I do claim exclusive right.
+
+"It is obvious that, to derive advantage from an application of this
+principle, it is absolutely necessary that the vessel or vessels for
+generating steam should have strength sufficient to withstand the
+great pressure from an increase of elasticity in the steam; but this
+pressure is increased or diminished in proportion to the capacity of
+the containing vessel. The principle, then, of this invention consists
+in forming a boiler by means of a system, or combination of a number
+of small vessels, instead of using, as in the usual mode, one large
+one; the relative strength of the materials of which these vessels
+are composed increasing in proportion to the diminution of capacity.
+It will readily occur that there are an infinite variety of possible
+modes of effecting such combinations; but, from the nature of the
+case, there are certain limits beyond which it becomes impracticable
+to carry on improvement. In the boiler I am about to describe, I
+apprehend that the improvement is carried to the utmost extent of
+which the principle is capable. Suppose a plate of brass of one foot
+square, in which a number of holes are perforated; into each of which
+holes is fixed one end of a copper tube, of about an inch in diameter
+and two feet long; and the other ends of these tubes inserted in like
+manner into a similar piece of brass; the tubes, to insure their
+tightness, to be cast in the plates; these plates are to be inclosed
+at each end of the pipes by a strong cap of cast-iron or brass, so as
+to leave a space of an inch or two between the plates or ends of the
+pipes and the cast-iron cap at each end; the caps at each end are to
+be fastened by screw-bolts passing through them into the plates; the
+necessary supply of water is to be injected by means of a forcing-pump
+into the cap at one end, and through a tube inserted into the cap at
+the other end the steam is to be conveyed to the cylinder of the
+steam-engine; the whole is then to be encircled in brickwork or
+masonry in the usual manner, placed either horizontally or
+perpendicularly, at option.
+
+"I conceive that the boiler above described embraces the most eligible
+mode of applying the principle before mentioned, and that it is
+unnecessary to give descriptions of the variations in form and
+construction that may be adopted, especially as these forms may be
+diversified in many different modes."
+
+Boilers of the character of those described in the specification given
+above were used on the locomotive built by John Stevens in 1824-'25,
+and one of them remains in the collections of the Stevens Institute of
+Technology.
+
+The use of such a boiler 70 years ago is even more remarkable than the
+adoption of the screw-propeller, in such excellent proportions, 30
+years before the labors of Smith and of Ericsson brought the screw
+into general use; and we have, in this strikingly original
+combination, as good evidence of the existence of unusual engineering
+talent in this great engineer as we found of his political and
+statesmanlike ability in his efforts to forward the introduction of
+railways.
+
+Colonel John Stevens designed a peculiar form of iron-clad in the year
+1812, which has been since reproduced by no less distinguished and
+successful an engineer than the late John Elder, of Glasgow, Scotland.
+It consisted of a saucer-shaped hull, carrying a heavy battery, and
+plated with iron of ample thickness to resist the shot fired from the
+heaviest ordnance then known. This vessel was secured to a swivel, and
+was anchored in the channel to be defended. A set of screw-propellers,
+driven by steam-engines, and situated beneath the vessel, where they
+were safe against injury by shot, were so arranged as to permit the
+vessel to be rapidly revolved about its centre. As each gun was
+brought into line of fire, it was discharged, and was then reloaded
+before coming around again. This was probably the earliest embodiment
+of the now well-established "Monitor" principle. It was probably the
+first iron-clad ever designed. It has recently been again brought out
+and introduced into the Russian navy, and is there called the
+"Popoffka."
+
+The first of Stevens's boats performed so well, that he immediately
+built another one, using the same engine as before, but employing a
+larger boiler, and propelling the vessel by _twin screws_, the latter
+being another instance of his use of a device brought forward long
+afterward as new, and frequently adopted. This boat was sufficiently
+successful to prove the practicability of making steam-navigation a
+commercial success; and Stevens, assisted by his sons, built a boat
+which he named the "Ph[oe]nix," and made the first trial in 1807, but
+just too late to anticipate Fulton. This boat was driven by
+paddle-wheels.
+
+[Illustration: FIG. 86.--Stevens's Twin-Screw Steamer, 1805.]
+
+The Ph[oe]nix, being shut out of the waters of the State of New York
+by the monopoly held by Fulton and Livingston, was used for a time
+between New York and New Brunswick, and then, anticipating a better
+pecuniary return, it was concluded to send her to Philadelphia, to ply
+on the Delaware.
+
+At that time no canal offered the opportunity to make an inland
+passage; and in June, 1808, Robert L. Stevens, a son of John, started
+with her to make the passage by sea. Although meeting a gale of wind,
+he arrived at Philadelphia safely, having been the first to trust
+himself on the open sea in a vessel relying entirely upon steam-power.
+
+From this time forward the Stevenses, father and sons, continued to
+construct steam-vessels; and, after the breaking down of the Fulton
+monopoly by the courts, they built the most successful steamboats that
+ran on the Hudson River.
+
+After Fulton and Stevens had thus led the way, steam-navigation was
+introduced very rapidly on both sides of the ocean; and on the
+Mississippi the number of boats set afloat was soon large enough to
+fulfill Evans's prediction that the navigation of that river would
+ultimately be effected by steam-vessels.
+
+The changes and improvements which, during the 20 years succeeding the
+time of Fulton and of John Stevens, gradually led to the adoption of
+the now recognized type of "American river-boat" and its steam-engine,
+were principally made by that son of the senior Stevens, who has
+already been mentioned--ROBERT L. STEVENS--and who became known later
+as the designer and builder of the first well-planned iron-clad ever
+constructed, the Stevens Battery. Much of his best work was done
+during his father's lifetime.
+
+[Illustration: Robert L. Stevens.]
+
+He made many extended and most valuable, as well as interesting,
+experiments on ship-propulsion, expending much time and large sums of
+money upon them; and many years before they became generally
+understood, he had arrived at a knowledge not only of the laws
+governing the variation of resistance at excessive speeds, but he had
+determined, and had introduced into his practice, those forms of least
+resistance and those graceful water-lines which have only recently
+distinguished the practice of other successful naval architects.
+
+Referring to his invaluable services, President King, who seems to
+have been the first to thoroughly appreciate the immense amount of
+original invention and the surprising excellence of the engineering of
+this family, in a lecture delivered in New York in 1851, gave, for the
+first time, a connected and probably accurate description of their
+work, upon which nearly all later accounts have been based.
+
+Young Stevens began working in his father's machine-shop in 1804 or
+1805, when a mere boy, and thus acquired at a very early age that
+familiarity with practical details of work and of business which is
+essential to perfect success. It was he who introduced the now common
+"hollow water-line" in the Ph[oe]nix, and thus anticipated the claims
+of the builders of the once famous "Baltimore clippers," and of the
+inventors of the "wave-line" form of vessels. In the same vessel he
+adopted a feathering paddle-wheel and the guard-beam now universally
+seen in our river steamboats.
+
+As usually constructed, this arrangement of float is as shown in Fig.
+87. The rods, _F F_, connect the eccentrically-set collar, _G_,
+carried on _H_, a pin mounted on the paddle-beam outside the wheel, or
+an eccentric secured to the vessel, with the short arms, _D D_, by
+which the paddles are turned upon the pins, _E E_. _A_ is the centre
+of the paddle-wheel, and _C C_ are arms. Circular hoops, or bands,
+connect all of the arms, each of which carries a float. They are all
+thus tied together, forming a very firm and powerful combination to
+resist external forces.
+
+[Illustration: FIG. 87.--The Feathering Paddle-Wheel.]
+
+The steamboat Philadelphia was built in the year 1813, and the young
+naval architect took advantage of the opportunity to introduce several
+new devices, including screw-bolts in place of tree-nails, and
+diagonal knees of wood and of iron. Two years later he altered the
+engines of this boat, and arranged them to work steam expansively. A
+little later he commenced using anthracite coal, which had been
+discovered in 1791 by Philip Ginter, and introduced at Wilkesbarre,
+Pa., in the smith-shops, some years before the Revolution. It had been
+used in a peculiar grate devised by Judge Fell, of that town, in 1808.
+Oliver Evans also had used it in stoves even earlier than the latter
+date, and at about the same time it had been used in the
+blast-furnace[81] at Kingston. Stevens was the first of whom we have
+record who was thoroughly successful in using, as a steam-coal, the
+new and almost unmanageable fuel. He fitted up the boiler of the
+steamboat Passaic for it in 1818, and adopted anthracite as a
+steaming-coal. He used it in a cupola-furnace in the same year, and
+its use then rapidly became general in the Eastern States.
+
+  [81] Bishop.
+
+Stevens continued his work of improving the beam-engine for many
+years. He designed the now universally-used "skeleton-beam," which is
+one of the characteristic features of the American engine, and placed
+the first example of this light and elegant, yet strong, construction
+on the steamer Hoboken in the year 1822. He built the Trenton, which
+was then considered an extraordinarily powerful, fast, and handsome
+vessel, two years afterward, and placed the two boilers on the
+guards--a custom which is still general on the river steamboats of the
+Eastern States. In this vessel he also adopted the plan of making the
+paddle-wheel floats in two parts, placing one above the other, and
+securing the upper half on the forward and the lower half on the after
+side of the arm, thus obtaining a smoother action of the wheel, and
+less loss by oblique pressures.
+
+In 1827 he built the North America (Fig. 88), one of his largest and
+most successful steamers, a vessel fitted with a pair of engines each
+44-1/2 inches in diameter of cylinder and 8 feet stroke of piston,
+making 24 revolutions per minute, driving the boat 15 to 16 miles an
+hour. Anticipating difficulty in keeping the long, light, shallow
+vessel in shape when irregularly laden, and when steaming at the high
+speed expected to be obtained when her powerful engine was exerting
+its maximum effort, he adopted the expedient of stiffening the hull by
+means of a truss of simple form. This proved thoroughly satisfactory,
+and the "hog-frame," as it has since been inelegantly but universally
+called, is still one of the peculiar features of every American
+river-steamer of any considerable size. It was in the North America,
+also, that he first introduced the artificial blast for forcing the
+fires, which is still another detail of now usual practice.
+
+[Illustration: FIG. 88.--The North America and Albany, 1827-'30.]
+
+Stevens next turned his attention to the engine again, and adopted
+spring bearings under the paddle-shaft of the New Philadelphia in
+1828, and fitted the steam-cylinder with the "double-poppet" valve,
+which is now universally used on beam-engines. This consists of two
+disk-valves, connected by the valve-spindle. The disks are of unequal
+sizes, the smaller passing through the seat of the larger. When
+seated, the pressure of the steam is, in the steam-valve, taken on the
+upper side of the larger and the lower side of the smaller disk, thus
+producing a partial balancing of the valve, and rendering it easy to
+work the heaviest engine by the hand-gear. The two valve-seats are
+formed in the top and the bottom, respectively, of the steam-passage
+leading to the cylinder; and when the valve is raised, the steam
+enters at the top and the bottom at the same time, and the two
+currents, uniting, flow together into the steam-cylinder. The same
+form of valve is used as an exhaust-valve.
+
+At about the same time he built the now standard form of return
+tubular boilers for moderate pressures. In the figure, _S_ is the
+steam and _W_ the water space, and _F_ the furnace. The direction of
+the currents of smoke and gas are shown by the arrows.
+
+[Illustration: FIG. 89.--Stevens's Return Tubular Boiler, 1832.]
+
+Some years later (1840), Stevens commenced using steam-packed pistons
+on the Trenton, in which steam was admitted by self-adjusting valves
+behind the metallic packing-rings, setting them out more effectively
+than did the steel springs then (and still) usually employed.
+
+His pistons, thus fitted, worked well for many years. A set of the
+small brass check-valves used in a piston of this kind, built by
+Stevens, and preserved in the cabinets of the Stevens Institute of
+Technology, are good evidence of the ingenuity and excellent
+workmanship which distinguished the machinery constructed under the
+direction of this great engineer.
+
+[Illustration: FIG. 90.--Stevens's Valve-Motion.]
+
+The now familiar "Stevens cut-off," a peculiar device for securing the
+expansion of steam in the steam-cylinder, was the invention (1841) of
+Robert L. Stevens and a nephew, who inherited the same constructive
+talent which distinguished the first of these great men--Mr. Francis
+B. Stevens. In this form of valve-gear, the steam and exhaust valves
+are independently worked by separate eccentrics, the latter being set
+in the usual manner, opening and closing the exhaust-passages just
+before the crank passes its centre. The steam-eccentric is so placed
+that the steam-valve is opened as usual, but closed when but about
+one-half the stroke has been made. This result is accomplished by
+giving the eccentric a greater throw than is required by the motion of
+the valve, and permitting it to move through a portion of its path
+without moving the valve. Thus, in Fig. 90, if _A B_ be the direction
+of motion of the eccentric-rod, the valve would ordinarily open the
+steam-port when the eccentric assumes the position _O C_, closing when
+the eccentric has passed around to _O D_. With the Stevens valve-gear,
+the valve is opened when the eccentric reaches _O E_, and closes when
+it arrives at _O F_. The steam-valve of the opposite end of the
+cylinder is open while the eccentric is moving from _O M_ to _O K_.
+Between _K_ and _E_, and between _F_ and _M_, both valves are seated.
+_H B_ is proportional to the lift of the valve, and _O H_ to the
+motion of the valve-gear when out of contact with the valve-lifters.
+While the crank is moving through an arc, _E F_, steam is entering the
+cylinder; from _F_ to _M_ the steam is expanding. At _M_ the stroke is
+completed, and the other steam-valve opens. The ratio (E M)/(E L) is
+the ratio of expansion.
+
+This form of cut-off motion is still a very usual one, and can be seen
+in nearly all steamers in the United States not using the device of
+Sickles. It was at about this time, also, that Stevens, having
+succeeded his father in the business of introducing the steam-engine
+in land-transportation, as well as on the water, adopted the use of
+steam expansively on the locomotives of the Camden & Amboy Railroad,
+which was controlled and built by capital furnished principally by the
+Messrs. Stevens. He at the same time constructed eight-wheeled engines
+for heavy work, and adopted anthracite coal as fuel. In the latter
+change he was thoroughly successful, and the same improvement was made
+with engines built for fast traffic in 1848.
+
+The most remarkable of all the applications of steam-power proposed by
+Robert L. Stevens was that known as the Stevens Steam Iron-Clad
+Battery. As has already been stated, Colonel John Stevens had
+proposed, as early as 1812, to build a circular or saucer-shaped
+iron-clad, like those built 60 years later for the Russian Navy.
+Nothing was done, however, although the son revived the idea in a
+modified form 20 years afterward. In the years 1813-'14, the war with
+England being then in progress, he invented, after numerous and
+hazardous experiments, an _elongated shell_, to be fired from ordinary
+smooth-bored cannon. Having perfected this invention, he sold the
+secret to the United States, after making experiments to prove their
+destructiveness so decisive as to leave no doubt of the efficacy of
+such projectiles.
+
+As early as 1837 he had perfected a plan of an iron-clad war-vessel,
+and in August, 1841, his brothers, James C. and Edwin A. Stevens,
+representing Robert L., addressed a letter to the Secretary of the
+Navy, proposing to build an iron-clad vessel of high speed, with all
+its machinery below the water-line, and having submerged
+screw-propellers. The armament was to consist of the most powerful
+rifled guns, loading at the breech, and provided with elongated shot
+and shell. In the year 1842, having contracted to build for the United
+States Government a large war-steamer on this plan, which should be
+shot and shell proof, Robert L. Stevens built a steamboat at
+Bordentown, for the sole purpose of experimenting on the forms and
+curves of propeller-blades, as compared with side-wheels, and
+continued his experiments for many months. After some delay, during
+which Mr. Stevens and his brothers were engaged with their experiments
+and in perfecting their plans, the keel of an iron-clad was laid down
+in a dry-dock which had been constructed for the purpose at great
+cost. This vessel was to have been 250 feet long, of 40 feet beam, and
+28 feet deep. The machinery was designed to furnish 700 indicated
+horse-power. The plating was proposed to be 4-1/2 inches thick--the
+same thickness of armor as was adopted 10 years later by the French
+for their comparatively rude constructions.
+
+In 1854, such marked progress had been made in the construction of
+ordnance that Mr. Stevens was no longer willing to proceed with the
+original plans, fearing that, were the ship completed, it might prove
+not invulnerable, and might throw some discredit upon its designer, as
+well as upon the navy of which it was to form a part. The work, which
+had, in those years of peace, progressed very slowly and
+intermittently, was therefore stopped entirely, the vessel given up,
+and in 1854 the keel of a ship of vastly greater size and power was
+laid down. The new design was 415 feet long, of 45 feet beam, and of
+something over 5,000 tons displacement. The thickness of armor
+proposed was 6-3/4 inches--2-1/4 inches thicker than that of the
+first French and British iron-clads--and the machinery was designed by
+Mr. Stevens to be of 8,624 indicated horse-power, driving twin-screws,
+and propelling the vessel 20 miles or more an hour. As with the
+preceding design, the progress of construction was intermittent and
+very slow. Government advanced funds, and then refused to continue the
+work; successive administrations alternately encouraged and
+discouraged the engineer; and he finally, cutting loose entirely from
+all official connections, went on with the work at his own expense.
+
+The remarkable genius of the elder Stevens was well reflected in the
+character of his son, and is in no way better exemplified than by the
+accuracy with which, in this great ship, those forms and proportions,
+both of hull and machinery, were adopted which are now, twenty-five
+years later, recognized as most correct under similar conditions. The
+lines of the vessel are beautifully fair and fine, and are what J.
+Scott Russell has called "wave-lines," or trochoidal lines, such as
+Rankine has shown to be the best possible for easy propulsion. The
+proportion of length to midship dimensions is such as to secure the
+speed proposed with a minimum resistance, and to accord closely with
+the proportions arrived at and adopted by common consent in present
+transoceanic navigation by the best--not to say radical--builders.
+
+The death of Robert L. Stevens occurred in April, 1856, when this
+larger vessel had advanced so far toward completion that the hull and
+machinery were practically finished, and it only remained to add the
+armor-plating, and to decide upon the form of fighting-house and upon
+the number and size of guns. The construction of the vessel, which had
+proceeded slowly and intermittently during the years of peace, as
+successive administrations had considered it necessary to continue the
+payment of appropriations, or had stopped temporarily in the absence
+of any apparent immediate necessity for continuance of the work, was
+again interrupted by his death.
+
+The name of Robert L. Stevens will be long remembered as that of one
+of the greatest of American mechanics, the most intelligent of naval
+architects, and as the first, and one of the greatest, of those to
+whom we are indebted for the commencement of the mightiest of
+revolutions in the methods and implements of modern naval warfare.
+American mechanical genius and engineering skill have rarely been too
+promptly recognized, and no excuse will be required for an attempt
+(which it is hoped may yet be made) to place such splendid work as
+that of the Messrs. Stevens in a light which shall reveal both its
+variety and extent and its immense importance.
+
+While Fulton was introducing the steamboat upon the waters of New York
+Bay and the Hudson River, and while the Stevenses, father and sons,
+were rapidly bringing out a fleet of steamers on the Delaware River
+and Bay, other mechanics were preparing to contest the field with them
+as opportunity offered, and as legislative acts authorizing monopoly
+expired by limitation or were repealed.
+
+About 1821, Robert L. Thurston, John Babcock, and Captain Stephen T.
+Northam, of Newport, R. I., commenced building steamboats, beginning
+with a small craft intended for use at Slade's Ferry, on an arm of
+Narragansett Bay, near Fall River. They afterward built vessels to ply
+on Long Island Sound. One of their earliest boats was the Babcock,
+built at Newport in 1826. The engine was built by Thurston and
+Babcock, at Portsmouth, R. I. They were assisted in their work by
+Richard Sanford, and with funds by Northam. The engine was of 10 or 12
+inches diameter of cylinder, and 3 or 4 feet stroke of piston. The
+boiler was a form of "pipe-boiler," subsequently (1824) patented by
+Babcock. The water used was injected into the hot boiler as fast as
+required to furnish steam, no water being retained in the
+steam-generator. This boat was succeeded, in 1827-'28, by a larger
+vessel, the Rushlight, for which the engine was built by James P.
+Allaire, at New York, while the boat was built at Newport. The boilers
+of both vessels had tubes of cast-iron. The smaller of these boats was
+of 80 tons burden; it steamed from Newport to Providence, 30 miles, in
+3-1/2 hours, and to New York, a distance of 175 miles, in 25 hours,
+using 1-3/4 cord of wood.[82] Thurston and Babcock subsequently
+removed to Providence, where the latter soon died. Thurston continued
+to build steam-engines at this place until nearly a half-century
+later, dying in 1874.[83] The establishment founded by him, after
+various changes, became the Providence Steam-Engine Works.
+
+  [82] _American Journal of Science_, March, 1827; _London Mechanics'
+  Magazine_, June 16, 1827.
+
+  [83] "New Universal Cyclopaedia," vol. iv., 1878.
+
+James P. Allaire, of New York, the West Point Iron Foundery, at West
+Point, on the Hudson River, and Daniel Copeland and his son, Charles
+W. Copeland, on the Connecticut River, were also early builders of
+engines for steam-vessels. Daniel Copeland was probably the first
+(1850) to adopt a slide-valve working with a lap to secure the
+expansion of steam. His steamboats were then usually stern-wheel
+vessels, and were built to ply on several routes on the Connecticut
+River and Long Island Sound. The son, Charles W. Copeland,
+went to West Point, and while there designed some heavy marine
+steam-machinery, and subsequently designed several steam
+vessels-of-war for the United States Navy. He was the earliest
+designer of iron steamers in the United States, building the Siamese
+in 1838. This steamer was intended for use on Lake Pontchartrain and
+the canal to New Orleans. It had two hulls, was 110 feet long, and
+drew but 22 inches of water, loaded. The two horizontal non-condensing
+engines turned a single paddle-wheel placed between the two hulls,
+driving the boat 10 miles an hour. The hull was constructed of plates
+of iron 10 feet long, formed on blocks after having been heated in a
+furnace constructed especially for the purpose. The frames were of
+T-iron, which was probably here used for the first time. The same
+engineer, associated with Samuel Hart, a well-known naval constructor,
+built, in 1841, for the United States Navy, the iron steamer Michigan,
+a war-vessel intended for service on the great northern lakes. This
+vessel is still in service, and in good order. The hull is 162-1/2
+feet in length, 27 feet in breadth, and 12-1/2 feet in depth,
+measuring 500 tons. The frames were made of T-iron, stiffened by
+reverse bars of L-iron. The keel-plate was 5/8 inch thick, the bottom
+plates 3/8, and the sides 3/16 inch. The deck-beams were of iron, and
+the vessel, as a whole, was a good specimen of iron-ship building.
+
+During the period from 1830 to 1840, a considerable number of the now
+standard details of steam-engine and steamboat construction were
+devised or introduced by Copeland. He was probably the first to use
+(on the Fulton, 1840) an independent engine to drive the blowing-fans
+where an artificial draught was required. He made a practice of
+fitting his steamers with a "bilge-injection," by means of which the
+vessel could be freed of water, through the condenser and air-pump,
+when leaking seriously; the condensing-water is, in such a case, taken
+from inside the vessel, instead of from the sea. This is probably an
+American device. It was in use in the United States previously to
+1835, as was the use of anthracite coal on steamers, which was
+continued by Copeland in manufacturing and in air-furnaces, as well as
+on steamboats. He also modified the form of Stevens's double-poppet
+valve, giving it such shape that it was comparatively easy to grind it
+tight and to keep it in order.
+
+In 1825, James P. Allaire, of New York, built compound engines for the
+Henry Eckford, and subsequently constructed similar engines for
+several other steamers, one of which, the Sun, made the trip from New
+York to Albany in 12 hours 18 minutes. He used steam at 100 pounds
+pressure. Erastus W. Smith afterward introduced this form of engine on
+the Great Lakes, and still later they were introduced into British
+steamers. The machinery of the steamer Buckeye State was constructed
+at the Allaire Works, New York, in 1850, from the designs of John
+Baird and Erastus W. Smith, the latter being the designing and
+constructing engineer. The steamer was placed on the route between
+Buffalo, Cleveland, and Detroit, in 1851, and gave most satisfactory
+results, consuming less than two-thirds the fuel required by a similar
+vessel of the same line fitted with the single-cylinder engine. The
+steam-cylinders of this engine were placed one within the other, the
+low-pressure exterior cylinder being annular. They were 37 and 80
+inches in diameter respectively, and the stroke was 11 feet. Both
+pistons were connected to one cross-head, and the general arrangement
+of the engine was similar to that of the common form of beam-engine.
+The steam-pressure was from 70 to 75 pounds--about the maximum
+pressure adopted a quarter of a century later on transatlantic lines.
+This steamer was of high speed, as well as economical of fuel.
+
+In the year 1830, there were 86 steamers on the Hudson River and in
+Long Island Sound.
+
+During the early part of the nineteenth century, the introduction of
+the steamboat upon the waters of the great rivers of the interior of
+the United States was one of the most notable details of its history.
+Inaugurated by the unsuccessful experiment of Evans, the building of
+steamboats on those waters, once commenced, never ceased; and a
+generation after Fitch's burial on the shore of the Ohio, his last
+wish--that he might lie "where the song of the boatman would enliven
+the stillness of his resting-place, and the music of the steam-engine
+soothe his spirit"--was fulfilled day by day unceasingly.
+
+Nicholas J. Roosevelt was, as has been already stated, the first to
+take a steamboat down the great rivers. His boat was built at
+Pittsburgh in 1811, under an arrangement with Fulton and Livingston,
+from Fulton's plans. It was called the "New Orleans," was of about 200
+tons burden, and was propelled by a stern-wheel, assisted, when the
+winds were favorable, by sails carried on two masts. The hull was 138
+feet long, 30 feet beam, and the cost of the whole, including engines,
+was about $40,000. The builder, with his family, an engineer, a pilot,
+and six "deck-hands," left Pittsburgh in October, 1811, reaching
+Louisville in 70 hours (steaming about 10 miles an hour), and New
+Orleans in 14 days, steaming from Natchez.
+
+The next steamers built on Western waters were probably the Comet and
+the Vesuvius, both of which were in service some time. The Comet was
+finally laid aside, and the engine used to drive a mill, and the
+Vesuvius was destroyed by the explosion of her boilers. As early as
+1813 there were two shops at Pittsburgh building steam-engines.
+Steamboat-building now became an important and lucrative business in
+the West; and it is stated that as early as 1840 there were a thousand
+steamers on the Mississippi and its tributaries.
+
+In the Washington, built at Wheeling, Va., in 1816, under the
+direction of Captain Henry M. Shreve, the boilers, which had
+previously been placed in the hold, were carried on the main-deck, and
+a "hurricane-deck" was built over them. Shreve substituted two
+horizontal direct-acting engines for the single upright engine used by
+Fulton, drove them by high-pressure steam without condensation, and
+attached them, one on each side the boat, to cranks placed at right
+angles. He adopted a cam cut-off expanding the steam considerably, and
+the flue-boiler of Evans. At that time the voyage from New Orleans to
+Louisville occupied three weeks, and Shreve was made the subject of
+many witticisms when he predicted that the time would ultimately be
+shortened to ten days. It is now made in four days. The Washington was
+seized at New Orleans, in 1817, by order of Livingston, who claimed
+that his rights included the monopoly of the navigation of the
+Mississippi and its tributaries. The courts decided adversely on this
+claim, and the release of the Washington was the act which removed
+every obstacle to the introduction of steam-navigation throughout the
+United States.
+
+The first steamer on the Great Lakes was the Ontario, built in 1816,
+at Sackett's Harbor. Fifteen years later, Western steamboats had taken
+the peculiar form which has since usually distinguished them.
+
+The use of the steam-engine for ocean-navigation kept pace with its
+introduction on inland waters. Begun by Robert L. Stevens in the
+United States, in the year 1808, and by his contemporaries, Bell and
+Dodd, in Great Britain, it steadily and rapidly advanced in
+effectiveness and importance, and has now nearly driven the sailing
+fleet from the ocean. Transatlantic steam-navigation began with the
+voyage of the American steamer Savannah from Savannah, Ga., to St.
+Petersburg, Russia, _via_ Great Britain and the North-European ports,
+in the year 1819. Fulton, not long before his death, planned a vessel,
+which it was proposed to place in service in the Baltic Sea; but
+circumstances compelled a change of plan finally, and the steamer was
+placed on a line between Newport, R. I., and the city of New York; and
+the Savannah, several years later, made the voyage then proposed for
+Fulton's ship. The Savannah measured 350 tons, and was constructed by
+Crocker & Fickett, at Corlears Hook, N. Y. She was purchased by Mr.
+Scarborough, of Savannah, who placed Captain Moses Rogers, previously
+in command of the Clermont and of Stevens's boat, the Ph[oe]nix, in
+charge. The ship was fitted with steam-machinery and paddle-wheels,
+and sailed for Savannah April 27, 1819, making the voyage successfully
+in seven days. From Savannah, the vessel sailed for Liverpool May
+26th, and arrived at that port June 20th. During this trip the engines
+were used 18 days, and the remainder of the voyage was made under
+sail. From Liverpool the Savannah sailed, July 23d, for the Baltic,
+touching at Copenhagen, Stockholm, St. Petersburg, and other ports. At
+St. Petersburg, Lord Lyndock, who had been a passenger, was landed;
+and, on taking leave of the commander of the steamer, the
+distinguished guest presented him with a silver tea-kettle, suitably
+inscribed with a legend referring to the importance of the event which
+afforded him the opportunity. The Savannah left St. Petersburg in
+November, passing New York December 9th, and reaching Savannah in 50
+days from the date of departure, stopping four days at Copenhagen,
+Denmark, and an equal length of time at Arundel, Norway. Several
+severe gales were met in the Atlantic, but no serious injury was done
+to the ship.
+
+The Savannah was a full-rigged ship. The wheels were turned by an
+inclined direct-acting low-pressure engine, having a steam-cylinder 40
+inches in diameter and 6 feet stroke of piston. The paddle-wheels were
+of wrought-iron, and were so attached that they could be detached and
+hoisted on board when it was desired. After the return of the ship to
+the United States, the machinery was removed and was sold to the
+Allaire Works, of New York. The steam-cylinder was exhibited by the
+purchasers at the "World's Fair" at New York thirty years later. The
+vessel was employed, as a sailing-vessel, on a line between New York
+and Savannah, and was finally lost in the year 1822. Under sail, with
+a moderate breeze, this ship is said to have sailed about three knots,
+and to have steamed five knots. Pine-wood was used as the fuel, which
+fact accounts for the necessity of making the transatlantic voyage
+partly under sail.
+
+Renwick states that another vessel, ship-rigged and fitted with a
+steam-engine, was built at New York in 1819, to ply between New York
+and Charleston, and to New Orleans and Havana, and that it proved
+perfectly successful as a steamer, having good speed, and proving an
+excellent sea-boat. The enterprise was, however, pecuniarily a
+failure, and the vessel was sold to the Brazilian Government after the
+removal of the engine. In 1825 the steamer Enterprise made a voyage to
+India, sailing and steaming as the weather and the supply of fuel
+permitted. The voyage occupied 47 days.
+
+Notwithstanding these successful passages across the ocean, and the
+complete success of the steamboat in rivers and harbors, it was
+asserted, as late as 1838, by many who were regarded as authority,
+that the passage of the ocean by steamers was quite impracticable,
+unless possibly they could steam from the coasts of Europe to
+Newfoundland or to the Azores, and, replenishing their coal-bunkers,
+resume their voyages to the larger American ports. The voyage was,
+however, actually accomplished by two steamers in the year just
+mentioned. These were the Sirius, a ship of 700 tons and of 250
+horse-power, and the Great Western, of 1,340 tons and 450 horse-power.
+The latter was built for this service, and was a large ship for that
+time, measuring 236 feet in length. Her wheels were 28 feet in
+diameter, and 10 feet in breadth of face. The Sirius sailed from Cork
+April 4, 1838, and the Great Western from Bristol April 8th, both
+arriving at New York on the same day--April 23d--the Sirius in the
+morning, and the Great Western in the afternoon.
+
+The Great Western carried out of Bristol 660 tons of coal. Seven
+passengers chose to take advantage of the opportunity, and made the
+voyage in one-half the time usually occupied by the sailing-packets of
+that day. Throughout the voyage the wind and sea were nearly ahead,
+and the two vessels pursued the same course, under very similar
+conditions. Arriving at New York, they were received with the greatest
+possible enthusiasm. They were saluted by the forts and the men-of-war
+in the harbor; the merchant-vessels dipped their flags, and the
+citizens assembled on the Battery, and, coming to meet them in boats
+of all kinds and sizes, cheered heartily. The newspapers of the time
+were filled with the story of the voyage and with descriptions of the
+steamers themselves and of their machinery.
+
+A few days later the two steamers started on their return to Great
+Britain, the Sirius reaching Falmouth safely in 18 days, and the Great
+Western making the voyage to Bristol in 15 days, the latter meeting
+with head-winds and working, during a part of the time, against a
+heavy gale and in a high sea, at the rate of but two knots an hour.
+The Sirius was thought too small for this long and boisterous route,
+and was withdrawn and replaced on the line between London and Cork,
+where the ship had previously been employed. The Great Western
+continued several years in the transatlantic trade.
+
+Thus these two voyages inaugurated a transoceanic steam-service, which
+has steadily grown in extent and in importance. The use of steam-power
+for this work of extended ocean-transportation has never since been
+interrupted. During the succeeding six years the Great Western made 70
+passages across the Atlantic, occupying on the voyages to the westward
+an average of 15-1/2 days, and eastward 13-1/2. The quickest passage
+to New York was made in May, 1843, in 12 days and 18 hours, and the
+fastest steaming was logged 12 months earlier, when the voyage from
+New York was made in 12 days and 7 hours.
+
+Meantime, several other steamers were built and placed in the
+transatlantic trade. Among these were the Royal William, the British
+Queen, the President, the Liverpool, and the Great Britain. The
+latter, the finest of the fleet, was launched in 1843. This steamer
+was 300 feet long, 50 feet beam, and of 1,000 horse-power. The hull
+was of iron, and the whole ship was an example of the very best work
+of that time. After several voyages, this vessel went ashore on the
+coast of Ireland, and there remained several weeks, but was finally
+got off, without having suffered serious injury--a remarkable
+illustration of the stanchness of an iron hull when well built and of
+good material. The vessel was repaired, and many years afterward was
+still afloat, and engaged in the transportation of passengers and
+merchandise to Australia.
+
+The "Cunard Line" of transatlantic steamers was established in the
+year 1840. The first of the line--the Britannia--sailed from Liverpool
+for New York, July 4th of that year, and was followed, on regular
+sailing-days, by the other three of the four ships with which the
+company commenced business. These four vessels had an aggregate
+tonnage of 4,600 tons, and their speed was less than eight knots.
+To-day, the tonnage of a single vessel of the fleet exceeds that of
+the four; the total tonnage has risen to many times that above given.
+There are 50 steamers in the line, aggregating nearly 50,000
+horse-power. The speed of the steamships of the present time is double
+that of the vessels of that date, and passages are not infrequently
+made in eight days.
+
+The form of steam-engine in most general use at this time, on
+transatlantic steamers, was that known as the "side-lever engine." It
+was first given the standard form by Messrs. Maudsley & Co., of
+London, about 1835, and was built by them for steamers supplied to the
+British Government for general mail service.
+
+The steam-vessels of the time are well represented in the accompanying
+engraving (Fig. 91) of the steamship Atlantic--a vessel which was
+shortly afterward (1851) built as the pioneer steamer of the American
+"Collins Line." This steamship was one of several which formed the
+earliest of American steamship-lines, and is one of the finest
+examples of the type of paddle-steamers which was finally superseded
+by the later screw-fleets. The "Collins Line" existed but a very few
+years, and its failure was probably determined as much by the evident
+and inevitable success of screw-propulsion as by the difficulty of
+securing ample capital, complete organization, and efficient general
+management. This steamer was built at New York--the hull by William
+Brown, and the machinery by the Novelty Iron-Works. The length of the
+hull was 276 feet, its breadth 45 feet, and the depth of hold 31-1/2
+feet. The width over the paddle-boxes was 75 feet. The ship measured
+2,860 tons. The form of the hull was then peculiar in the fineness of
+its lines; the bow was sharp, and the stern fine and smooth, and the
+general outline such as best adapted the ship for high speed. The main
+saloon was about 70 feet long, and the dining-room was 60 feet in
+length and 20 feet wide. The state-rooms were arranged on each side
+the dining "saloon," and accommodated 150 passengers. These vessels
+were beautifully fitted up, and with them was inaugurated that
+wonderful system of passenger-transportation which has since always
+been distinguished by those comforts and conveniences which the
+American traveler has learned to consider his by right.
+
+[Illustration: FIG. 91.--The Atlantic, 1851.]
+
+The machinery of these ships was, for that time, remarkably powerful
+and efficient. The engines were of the side-lever type, as
+illustrated in Fig. 92, which represents the engine of the Pacific,
+designed by Mr. Charles W. Copeland, and built by the Allaire Works.
+
+[Illustration: FIG. 92.--The Side-Lever Engine, 1849.]
+
+In this type of engine, as is seen, the piston-rod was attached to a
+cross-head working vertically, from which, at each side, links, _B C_,
+connected with the "side-lever," _D E F_. The latter vibrated about a
+"main centre" at _E_, like the overhead beam of the more common form
+of engine; from its other end, a "connecting-rod," _H_, led to the
+"cross-tail," _W_, which was, in turn, connected to the crank-pin,
+_I_. The condenser, _M_, and air-pump, _Q_, were constructed in the
+same manner as those of other engines, their only peculiarities being
+such as were incident to their location between the cylinder, _A_, and
+the crank, _I J_. The paddle-wheels were of the common "radial" form,
+covered in by paddle-boxes so strongly built that they were rarely
+injured by the heaviest seas.
+
+These vessels surpassed, for a time, all other sea-going steamers in
+speed and comfort, and made their passages with great regularity. The
+minimum length of voyage of the Baltic and Pacific, of this line, was
+9 days 19 hours.
+
+During the latter part of the period the history of which has been
+here given, the marine steam-engine became subject to very marked
+changes in type and in details, and a complete revolution was effected
+in the method of propulsion. This change has finally resulted in the
+universal adoption of a new propelling instrument, and in driving the
+whole fleet of paddle-steamers from the ocean. The Great Britain was a
+screw-steamer.
+
+The screw-propeller, which, as has been stated, was probably first
+proposed by Dr. Hooke in 1681, and by Dr. Bernouilli, of Groningen, at
+about the middle of the eighteenth century, and by Watt in 1784, was,
+at the end of the century, tried experimentally in the United States
+by David Bushnell, an ingenious American, who was then conducting the
+experiments with torpedoes which were the cause of the incident which
+originated that celebrated song by Francis Hopkinson, the "Battle of
+the Kegs," using the screw to propel one of his submarine boats, and
+by John Fitch, and by Dallery in France.
+
+Joseph Bramah, of Great Britain, May 9, 1785, patented a
+screw-propeller identical in general arrangement with those used
+to-day. His sketch exhibits a screw, apparently of very fair shape,
+carried on an horizontal shaft, which passes out of the vessel through
+a stuffing-box, the screw being wholly submerged. Bramah does not seem
+to have put his plan in practice. It was patented again in England,
+also, by Littleton in 1794, and by Shorter in 1800.
+
+John Stevens, however, first gave the screw a practically useful
+form, and used it successfully, in 1804 and 1805, on the single and
+the twin screw boats which he built at that time. This propelling
+instrument was also tried by Trevithick, who planned a vessel to be
+propelled by a steam-engine driving a screw, at about this time, and
+his scheme was laid before the Navy Board in the year 1812. His plans
+included an iron hull. Francis Pettit Smith tried the screw also in
+the year 1808, and subsequently.
+
+Joseph Ressel, a Bohemian, proposed to use a screw in the propulsion
+of balloons, about 1812, and in the year 1826 proposed its use for
+marine propulsion. He is said to have built a screw-boat in the year
+1829, at Trieste, which he named the Civetta. The little craft met
+with an accident on the trial-trip, and nothing more was done.
+
+The screw was finally brought into general use through the exertions
+of John Ericsson, a skillful Swedish engineer, who was residing in
+England in the year 1836, and of Mr. F. P. Smith, an English farmer.
+Ericsson patented a peculiar form of screw-propeller, and designed a
+steamer 40 feet in length, of 8 feet beam, and drawing 3 feet of
+water. The screw was double, two shafts being placed the one within
+the other, revolving in opposite directions, and carrying the one a
+right-hand and the other a left-hand screw. These screws were 5-1/4
+feet in diameter. On her trial-trip this little steamer attained a
+speed of 10 miles an hour. Its power as a "tug" was found to be very
+satisfactory; it towed a schooner of 140 tons burden at the rate of 7
+miles, and the large American packet-ship Toronto was towed on the
+Thames at a speed of 5 miles an hour.
+
+Ericsson endeavored to interest the British Admiralty in his
+improvements, and succeeded only so far as to induce the Lords of the
+Admiralty to make an excursion with him on the river. No interest was
+awakened in the new system, and nothing was done by the naval
+authorities. A note to the inventor from Captain Beaufort--one of the
+party--was received shortly afterward, in which it was stated that
+the excursionists had not found the performance of the little vessel
+to equal their hopes and expectations. All the interests of the then
+existing engine-building establishments were opposed to the
+innovation, and the proverbial conservatism of naval men and naval
+administrations aided in procuring the rejection of Ericsson's plans.
+
+Fortunately for the United States, it happened, at that time, that we
+had in Great Britain both civil and naval representatives of greater
+intelligence, or of greater boldness and enterprise. The consul at
+Liverpool was Mr. Francis B. Ogden, of New Jersey, a gentleman who was
+somewhat familiar with the steam-engine and with steam-navigation. He
+had seen Ericsson's plans at an earlier period, and had at once seen
+their probable value. He was sufficiently confident of success to
+place capital at the disposal of the inventor. The little screw-boat
+just described was built with funds of which he furnished a part, and
+was named, in his honor, the Francis B. Ogden.
+
+Captain Robert F. Stockton, an officer of the United States Navy, and
+also a resident of New Jersey, was in London at the time, and made an
+excursion with Ericsson on the Ogden. He was also at once convinced of
+the value of the new method of application of steam-power to
+ship-propulsion, and gave the engineer an order to build two iron
+screw-steamboats for use in the United States. Ericsson was induced,
+by Messrs. Ogden and Stockton, to take up his residence in the United
+States.[84] The Stockton was sent over to the United States in April,
+1839, under sail, and was sold to the Delaware & Raritan Canal
+Company. Her name was changed, and, as the New Jersey, she remained in
+service many years.
+
+  [84] This distinguished inventor is still a resident of New York
+  (1878).
+
+The success of the boat built by Ericsson was so evident that,
+although the naval authorities remained inactive, a private company
+was formed, in 1839, to work the patents of F. P. Smith, and this
+"Ship-Propeller Company" built an experimental craft called the
+Archimedes, and its trial-trip was made October 14th of the same year.
+The speed attained was 9.64 miles an hour. The result was in every
+respect satisfactory, and the vessel, subsequently, made many voyages
+from port to port, and finally circumnavigated the island of Great
+Britain. The proprietors of the ship were not pecuniarily successful
+in their venture, however, and the sale of the vessel left the company
+a heavy loser. The Archimedes was 125 feet long, of 21 feet 10 inches
+beam, and 10 feet draught, registering 232 tons. The engines were
+rated at 80 horse-power. Smith's earlier experiments (1837) were made
+with a little craft of 6 tons burden, driven by an engine having a
+steam-cylinder 6 inches in diameter and 15 inches stroke of piston.
+The funds needed were furnished by a London banker--Mr. Wright.
+
+Bennett Woodcroft had also used the screw experimentally as early as
+1832, on the Irwell, near Manchester, England, in a boat of 55 tons
+burden. Twin-screws were used, right and left handed respectively;
+they were each two feet in diameter, and were given an expanding
+pitch. The boat attained a speed of four miles an hour.
+
+Experiments made subsequently (1843) with this form of screw, and in
+competition with the "true" screw of Smith, brought out very
+distinctly the superiority of the former, and gave some knowledge of
+the proper proportions for maximum efficiency. In later examples of
+the Woodcroft screw, the blades were made detachable and adjustable--a
+plan which is still a usual one, and which has proved to be, in some
+respects, very convenient.
+
+When Ericsson reached the United States, he was almost
+immediately given an opportunity to build the Princeton--a large
+screw-steamer--and at about the same time the English and French
+Governments also had screw-steamers built from his plans, or from
+those of his agent in England, the Count de Rosen. In these latter
+ships--the Amphion and the Pomona--the first horizontal direct-acting
+engines ever built were used, and they were fitted with double-acting
+air-pumps, having canvas valves and other novel features. The great
+advantages exhibited by these vessels over the paddle-steamers of the
+time did for screw-propulsion what Stephenson's locomotive--the
+Rocket--did for railroad locomotion ten years earlier.
+
+Congress, in 1839, had authorized the construction of three
+war-vessels, and the Secretary of the Navy ordered that two be at once
+built in the succeeding year. Of these, one was the Princeton, the
+screw-steamer of which the machinery was designed by Ericsson. The
+length of this vessel was 164 feet, beam 30-1/2 feet, and depth 21-1/2
+feet. The ship drew from 16-1/2 to 18 feet of water, displacing at
+those draughts 950 and 1,050 tons. The hull had a broad, flat floor,
+with sharp entrance and fine run, and the lines were considered at
+that time remarkably fine.
+
+The screw was of gun-bronze, six-bladed, and was 14 feet in diameter
+and of 35 feet pitch; i. e., were there no slip, the screw working as
+if in a solid nut, the ship would have been driven forward 35 feet at
+each revolution.
+
+The engines were two in number, and very peculiar in form; the
+cylinder was, in fact, a _semi_-cylinder, and the place of the
+piston-rod, as usually built, was taken by a vibrating shaft, or
+"rock-shaft," which carried a piston of rectangular form, and which
+vibrated like a door on its hinges as the steam was alternately let
+into and exhausted from each side of it. The great rock-shaft carried,
+at the outer end, an arm from which a connecting-rod led to the crank,
+thus forming a "direct-acting engine."
+
+The draught in the boilers was urged by blowers. Ericsson had adopted
+this method of securing an artificial draught ten years before, in one
+of his earlier vessels, the Corsair. The Princeton carried a XII-inch
+wrought-iron gun. This gun exploded after a few trials, with terribly
+disastrous results, causing the death of several distinguished men,
+including members of the President's cabinet.
+
+The Princeton proved very successful as a screw-steamer, attaining a
+speed of 13 knots, and was then considered very remarkably fast.
+Captain Stockton, who commanded the vessel, was most enthusiastic in
+praise of her.
+
+Immediately there began a revolution in both civil and naval
+ship-building, which progressed with great rapidity. The Princeton was
+the first of the screw-propelled navy which has now entirely displaced
+the older type of steam-vessel. The introduction of the screw now took
+place with great rapidity. Six steamers were fitted with Ericsson's
+screw in 1841, 9 in 1842, and nearly 30 in the year 1843.
+
+In Great Britain, France, Germany, and other European countries, the
+revolution was also finally effected, and was equally complete. Nearly
+all sea-going vessels built toward the close of the period here
+considered were screw-steamers, fitted with direct-acting,
+quick-working engines. It was, however, many years before the
+experience of engineers in the designing and in the construction and
+management of this new machinery enabled them to properly proportion
+it for the various kinds of service to which they were called upon to
+adapt it. Among other modifications of earlier practice introduced by
+Ericsson was the surface-condenser with a circulating pump driven by a
+small independent engine.
+
+The screw was found to possess many advantages over the paddle-wheel
+as an instrument for ship-propulsion. The cost of machinery was
+greatly reduced by its use; the expense of maintenance in working
+order was, however, somewhat increased. The latter disadvantage was,
+nevertheless, much more than compensated by an immense increase in the
+economy of ship-propulsion, which marked the substitution of the new
+instrument and its impelling machinery.
+
+When a ship is propelled by paddles, the motion of the vessel creates,
+in consequence of the friction of the fluid against the sides and
+bottom, a current of water which flows in the direction in which the
+ship is moving, and forms a current following the ship for a time, and
+finally losing all motion by contact with the surrounding mass of
+water. All the power expended in the production of this great stream
+is, in the case of the paddle-steamer, entirely lost. In
+screw-steamers, however, the propelling instrument works in this
+following current, and the tendency of its action is to bring the
+agitated fluid to rest, taking up and thus restoring, usefully, a
+large part of that energy which would otherwise have been lost. The
+screw is also completely covered by the water, and acts with
+comparative efficiency in consequence of its submersion. The rotation
+of the screw is comparatively rapid and smooth, also, and this permits
+the use of small, light, fast-running engines. The latter condition
+leads to economy of weight and space, and consequently saves not only
+the cost of transportation of the excess of weight of the larger kind
+of engine, but, leaving so much more room for paying cargo, the gain
+is found to be a double one. Still further, the quick-running engine
+is, other things being equal, the most economical of steam; and thus
+some expense is saved not only in the purchase of fuel, but in its
+transportation, and some still additional gain is derived from the
+increased amount of paying cargo which the vessel is thus enabled to
+carry. The change here described was thus found to be productive of
+enormous direct gain. Indirectly, also, some advantage was derived
+from the greater convenience of a deck clear from machinery and the
+great paddle-shaft, in the better storage of the lading, the greater
+facility with which the masts and sails could be fitted and used; and
+directly, again, in clear sides unencumbered by great paddle-boxes
+which impeded the vessel by catching both sea and wind.
+
+The screw was, for some years, generally regarded as simply auxiliary
+in large vessels, assisting the sails. Ultimately the screw became
+the essential feature, and vessels were lightly sparred and were given
+smaller areas of sail, the latter becoming the auxiliary power.
+
+In November of the year 1843, the screw-steamer Midas, Captain Poor, a
+small schooner-rigged craft, left New York for China, on probably the
+first voyage of such length ever undertaken by a steamer; and in the
+following January the Edith, Captain Lewis, a bark-rigged
+screw-vessel, sailed from the same port for India and China. The
+Massachusetts, Captain Forbes, a screw-steamship of about 800 tons,
+sailed for Liverpool September 15, 1845, the first voyage of an
+American transatlantic passenger-steamer since the Savannah's pioneer
+adventure a quarter of a century before. Two years later, American
+enterprise had placed both screw and paddle steamers on the rivers of
+China--principally through the exertions of Captain R. B. Forbes--and
+steam-navigation was fairly established throughout the world.
+
+On comparing the screw-steamer of the present time with the best
+examples of steamers propelled by paddle-wheels, the superiority of
+the former is so marked that it may cause some surprise that the
+revolution just described should have progressed no more rapidly. The
+reason of this slow progress, however, was probably that the
+introduction of the rapidly-revolving screw, in place of the
+slow-moving paddle-wheel, necessitated a complete revolution in the
+design of their steam-engines; and the unavoidable change from the
+heavy, long-stroked, low-speed engines previously in use, to the light
+engines, with small cylinders and high piston-speed, called for by the
+new system of propulsion, was one that necessarily occurred slowly,
+and was accompanied by its share of those engineering blunders and
+accidents that invariably take place during such periods of
+transition. Engineers had first to learn to design such engines
+as should be reliable under the then novel conditions of
+screw-propulsion, and their experience could only be gained through
+the occurrence of many mishaps and costly failures. The best
+proportions of engines and screws, for a given ship, were determined
+only by long experience, although great assistance was derived from
+the extensive series of experiments made with the French steamer
+Pelican. It also became necessary to train up a body of engine-drivers
+who should be capable of managing these new engines; for they required
+the exercise of a then unprecedented amount of care and skill.
+Finally, with the accomplishment of these two requisites to success
+must simultaneously occur the enlightenment of the public,
+professional as well as non-professional, in regard to their
+advantages. Thus it happens that it is only after a considerable time
+that the screw attained its proper place as an instrument of
+propulsion, and finally drove the paddle-wheel quite out of use,
+except in shoal water.
+
+Now our large screw-steamers are of higher speed than any
+paddle-steamers on the ocean, and develop their power at far less
+cost. This increased economy is due not only to the use of a more
+efficient propelling instrument, and to changes already described, but
+also, in a great degree, to the economy which has followed as a
+consequence of other changes in the steam-engine driving it. The
+earliest days of screw-propulsion witnessed the use of steam of from 5
+to 15 pounds pressure, in a geared engine using jet-condensation, and
+giving a horse-power at an expense of perhaps 7 to 10, or even more,
+pounds of coal per hour. A little later came direct-acting engines
+with jet-condensation and steam at 20 pounds pressure, costing about 5
+or 6 pounds per horse-power per hour. The steam-pressure rose a little
+higher with the use of greater expansion, and the economy of fuel was
+further improved. The introduction of the surface-condenser, which
+began to be generally adopted some ten years ago, brought down the
+cost of power to from 3 to 4 pounds in the better class of engines. At
+about the same time, this change to surface-condensation helping
+greatly to overcome those troubles arising from boiler-incrustation
+which had prevented the rise of steam-pressure above about 25 pounds
+per square inch, and as, at the same time, it was learned by engineers
+that the deposit of lime-scale in the marine boiler was determined by
+temperature rather than by the degree of concentration, and that all
+the lime entering the boiler was deposited at the pressure just
+mentioned, a sudden advance took place. Careful design, good
+workmanship, and skillful management, made the surface-condenser an
+efficient apparatus; and, the dangers of incrustation being thus
+lessened, the movement toward higher pressures recommenced, and
+progressed so rapidly that now 75 pounds per square inch is very
+usual, and more than 125 pounds has since been attained.
+
+The close of this period was marked by the construction of the most
+successful types of paddle-steamers, the complete success of
+transoceanic steam-transportation, the introduction of the
+screw-propeller and the peculiar engine appropriate to it, and,
+finally, a general improvement, which had finally become marked both
+in direction and in rapidity of movement, leading toward the use of
+higher steam-pressure, greater expansion, lighter and more
+rapidly-working machinery, and decidedly better design and
+construction, and the use of better material. The result of these
+changes was seen in economy of first cost and maintenance, and the
+ability to attain greater speed, and to assure greater safety to
+passengers and less risk to cargo.
+
+The introduction of the changes just noted finally led to the last
+great change in the form of the marine steam-engine, and a revolution
+was inaugurated, which, however, only became complete in the
+succeeding period. The non-success of Hornblower and of Wolff, and
+others who had attempted to introduce the "compound" or
+double-cylinder engine on land, had not convinced all engineers that
+it might not yet be made a successful rival of the then standard type;
+and the three or four steamers which were built for the Hudson River
+at the end of the first quarter of the nineteenth century are said to
+have been very successful vessels. Carrying 75 to 100 pounds of steam
+in their boilers, the Swiftsure and her contemporaries were by that
+circumstance well fitted to make that form of engine economically a
+success. This form of engine was built occasionally during the
+succeeding quarter of a century, but only became a recognized standard
+type after the close of the epoch to the history of which this chapter
+is devoted. That latest and greatest advance in the direction of
+increased efficiency in the marine steam-engine was, however,
+commenced very soon after Watt's death, and its completion was the
+work of nearly a half-century.
+
+[Illustration]
+
+
+
+
+CHAPTER VI.
+
+_THE STEAM-ENGINE OF TO-DAY._
+
+  ... "And, last of all, with inimitable power, and 'with whirlwind
+  sound,' comes the potent agency of steam. In comparison with the
+  past, what centuries of improvement has this single agent comprised
+  in the short compass of fifty years! Everywhere practicable,
+  everywhere efficient, it has an arm a thousand times stronger than
+  that of Hercules, and to which human ingenuity is capable of fitting
+  a thousand times as many hands as belonged to Briareus. Steam is
+  found in triumphant operation on the seas; and, under the influence
+  of its strong propulsion, the gallant ship--
+
+    'Against the wind, against the tide,
+    Still steadies with an upright keel.'
+
+  It is on the rivers, and the boatman may repose on his oars; it is
+  on highways, and exerts itself along the courses of land-conveyance;
+  it is at the bottom of mines, a thousand feet below the earth's
+  surface; it is in the mills, and in the workshops of the trades. It
+  rows, it pumps, it excavates, it carries, it draws, it lifts, it
+  hammers, it spins, it weaves, it prints. It seems to say to men, at
+  least to the class of artisans: 'Leave off your manual labor; give
+  over your bodily toil; bestow but your skill and reason to the
+  directing of my power, and I will bear the toil, with no muscle to
+  grow weary, no nerve to relax, no breast to feel faintness!' What
+  further improvement may still be made in the use of this astonishing
+  power it is impossible to know, and it were vain to conjecture. What
+  we do know is, that it has most essentially altered the face of
+  affairs, and that no visible limit yet appears beyond which its
+  progress is seen to be impossible."--DANIEL WEBSTER.
+
+
+THE PERIOD OF REFINEMENT--1850 TO DATE.
+
+By the middle of the present century, as we have now seen, the
+steam-engine had been applied, and successfully, to every great
+purpose for which it was fitted. Its first application was to the
+elevation of water; it next was applied to the driving of mills and
+machinery; and it finally became the great propelling power in
+transportation by land and by sea.
+
+At the beginning of the period to which we are now come, these
+applications of steam-power had become familiar both to the engineer
+and to the public. The forms of engine adapted to each purpose had
+been determined, and had become usually standard. Every type of the
+modern steam-engine had assumed, more or less closely, the form and
+proportions which are now familiar; and the most intelligent designers
+and builders had been taught--by experience rather than by theory, for
+the theory of the steam-engine had then been but little investigated,
+and the principles and laws of thermo-dynamics had not been traced in
+their application to this engine--the principles of construction
+essential to successful practice, and were gradually learning the
+relative standing of the many forms of steam-engine, from among which
+have been preserved a few specially fitted for certain specific
+methods of utilization of power.
+
+During the years succeeding the date 1850, therefore, the growth of
+the steam-engine had been, not a change of standard type, or the
+addition of new parts, but a gradual improvement in forms,
+proportions, and arrangements of details; and this period has been
+marked by the dying out of the forms of engine least fitted to succeed
+in competition with others, and the retention of the latter has been
+an example of "the survival of the fittest." This has therefore been a
+Period of Refinement.
+
+During this period invention has been confined to details; it has
+produced new forms of parts, new arrangements of details; it has
+devised an immense variety of valves, valve-motions, regulating
+apparatus, and a still greater variety of steam-boilers and of
+attachments, essential and non-essential, to both engines and boilers.
+The great majority of these peculiar devices have been of no value,
+and very many of the best of them have been found to have about equal
+value. All the well-known and successful forms of engine, when equally
+well designed and constructed and equally well managed, are of very
+nearly equal efficiency; all of the best-known types of steam-boiler,
+where given equal proportions of grate to heating-surface and equally
+well designed, with a view to securing a good draught and a good
+circulation of water, have been found to give very nearly equally good
+results; and it has become evident that a good knowledge of principles
+and of practice, on the part of the designer, the constructor, and the
+manager of the boiler, is essential in the endeavor to achieve
+economical success; that good engineering is demanded, rather than
+great ingenuity. The inventor has been superseded here by the
+engineer.
+
+The knowledge acquired in the time of Watt, of the essential
+principles of steam-engine construction, has since become generally
+familiar to the better class of engineers. It has led to the selection
+of simple, strong, and durable forms of engine and boiler, to the
+introduction of various kinds of valves and of valve-gearing, capable
+of adjustment to any desired range of expansive working, and to the
+attachment of efficient forms of governor to regulate the speed of the
+engine, by determining automatically the point of cut-off which will,
+at any instant, best adjust the energy exerted by the expanding steam
+to the demand made by the work to be done.
+
+The value of high pressures and considerable expansion was recognized
+as long ago as in the early part of the present century, and Watt, by
+combining skillfully the several principal parts of the steam-engine,
+gave it very nearly the shape which it has to-day. The compound
+engine, even, as has been seen, was invented by contemporaries of
+Watt, and the only important modifications since his time have
+occurred in details. The introduction of the "drop cut-off," the
+attachment of the governor to the expansion-apparatus in such a manner
+as to determine the degree of expansion, the improvement of
+proportions, the introduction of higher steam and greater expansion,
+the improvement of the marine engine by the adoption of
+surface-condensation, in addition to these other changes, and the
+introduction of the double-cylinder engine, after the elevation of
+steam-pressure and increase of expansion had gone so far as to justify
+its use, are the changes, therefore, which have taken place during
+this last quarter-century. It began then to be generally understood
+that expansion of steam produced economy, and mechanics and inventors
+vied with each other in the effort to obtain a form of valve-gear
+which should secure the immense saving which an abstract consideration
+of the expansion of gases according to Marriotte's law would seem to
+promise. The counteracting phenomena of internal condensation and
+reevaporation, of the losses of heat externally and internally, and of
+the effect of defective vacuum, defective distribution of steam, and
+of back-pressure, were either unobserved or were entirely overlooked.
+
+It was many years, therefore, before engine-builders became convinced
+that no improvement upon existing forms of expansion-gear could secure
+even an approximation to theoretical efficiency.
+
+The fact thus learned, that the benefit of expansive working has a
+limit which is very soon reached in ordinary practice, was not then,
+and has only recently become, generally known among our steam-engine
+builders, and for several years, during the period upon which we now
+enter, there continued the keenest competition between makers of rival
+forms of expansion-gear, and inventors were continually endeavoring to
+produce something which should far excel any previously-existing
+device.
+
+In Europe, as in the United States, efforts to "improve" standard
+designs have usually resulted in injuring their efficiency, and in
+simply adding to the first cost and running expense of the engines,
+without securing a marked increase in economy in the consumption of
+steam.
+
+
+SECTION I.--STATIONARY ENGINES.
+
+"STATIONARY ENGINES" had been applied to the operation of
+mill-machinery, as has been seen, by Watt and by Murdoch, his
+assistant and pupil; and Watt's competitors, in Great Britain and
+abroad, had made considerable progress before the death of the great
+engineer, in its adaptation to its work. In the United States, Oliver
+Evans had introduced the non-condensing high-pressure stationary
+engine, which was the progenitor of the standard engine of that type
+which is now used far more generally than any other form. These
+engines were at first rude in design, badly proportioned, rough and
+inaccurate as to workmanship, and uneconomical in their consumption of
+fuel. Gradually, however, when made by reputable builders, they
+assumed neat and strong shapes, good proportions, and were well made
+and of excellent materials, doing their work with comparatively little
+waste of heat or of fuel.
+
+One of the neatest and best modern designs of stationary engine for
+small powers is seen in Fig. 93, which represents a "vertical
+direct-acting engine," with base-plate--a form which is a favorite
+with many engineers.
+
+The engine shown in the engraving consists of two principal parts, the
+cylinder and the frame, which is a tapering column having openings in
+the sides, to allow free access to all the working parts within. The
+slides and pillow-blocks are cast with the column, so that they cannot
+become loose or out of line; the rubbing surfaces are large and easily
+lubricated. Owing to the vertical position, there is no tendency to
+side wear of cylinder or piston. The packing-rings are self-adjusting,
+and work free but tight. The crank is counterbalanced; the crank-pin,
+cross-head pin, piston-rod, valve-stem, etc., are made of steel; all
+the bearing surfaces are made extra large, and are accurately fitted;
+and the best quality of Babbitt-metal only used for the
+journal-bearings.
+
+[Illustration: FIG. 93.--Vertical Stationary Steam-Engine.]
+
+The smaller sizes of these engines, from 2 to 10 horse-power, have
+both pillow-blocks cast in the frame, giving a bearing each side of
+the double cranks. They are built by some constructors in quantities,
+and parts duplicated by special machinery (as in fire-arms and
+sewing-machines), which secures great accuracy and uniformity of
+workmanship, and allows of any part being quickly and cheaply
+replaced, when worn or broken by accident. The next figure is a
+vertical section through the same engine.
+
+[Illustration: FIG. 94.--Vertical Stationary Steam-Engine. Section.]
+
+Engines fitted with the ordinary rigid bearings require to be erected
+on a firm foundation, and to be kept in perfect line. If, by the
+settling of the foundation, or from any other cause, they get out of
+line, heating, cutting, and thumping result. To obviate this, modern
+engines are often fitted with self-adjusting bearings throughout; this
+gives the engine great flexibility and freedom from friction. The
+accompanying cuts show clearly how this is accomplished. The
+pillow-block has a spherical shell turned and fitted into the
+spherically-bored pillow-block, thus allowing a slight angular motion
+in any direction. The connecting-rod is forged in a single piece,
+without straps, gibs, or key, and is mortised through at each end for
+the reception of the brass boxes, which are curved on their backs, and
+fit the cheek-pieces, between which they can turn to adjust themselves
+to the pins, in the plane of the axis of the rod. The adjustment for
+wear is made by wedge-blocks and set screws, as shown, and they are so
+constructed that the parts cannot get loose and cause a break-down.
+The cross-head has adjustable gibs on each side, turned to fit the
+slides, which are cast solidly in the frame, and bored out exactly in
+the line with the cylinder. This permits it freely to turn on its
+axis, and, in connection with the adjustable boxes in the
+connecting-rod, allows a perfect self-adjustment to the line of the
+crank-pin. The out-board bearing may be moved an inch or more out of
+position in any direction, without detriment to the running of the
+engine, all bearings accommodating themselves perfectly to whatever
+position the shaft may assume.
+
+The ports and valve-passages are proportioned as in locomotive
+practice. The valve-seat is adapted to the ordinary plain slide or
+D-valve, should it be preferred, but the balanced piston slide-valve
+works with equal ease whether the steam-pressure is 10 or 100 pounds,
+and at the same time gives double steam and exhaust openings, which
+greatly facilitates the entrance of the steam to, and its escape from,
+the cylinder, thus securing a nearer approach to boiler-pressure and a
+less back-pressure, saving the power required to work an ordinary
+valve, and reducing the wear of valve-gear.
+
+This is a type of engine frequently seen in the United States, but
+more rarely in Europe. It is an excellent form of engine. The vertical
+direct-acting engine is sometimes, though rarely, built of very
+considerable size, and these large engines are more frequently seen in
+rolling-mills than elsewhere.
+
+Where much power is required, the stationary engine is usually an
+horizontal direct-acting engine, having a more or less effective
+cut-off valve-gear, according to the size of engine and the cost of
+fuel. A good example of the simpler form of this kind of engine is the
+small horizontal slide-valve engine, with independent cut-off valve
+riding on the back of the main valve--a combination generally known
+among engineers as the Meyer system of valve-gear. This form of
+steam-engine is a very effective machine, and does excellent work when
+properly proportioned to yield the required amount of power. It is
+well adapted to an expansion of from four to five times. Its
+disadvantages are the difficulty which it presents in the attachment
+of the regulator, to determine the point of cut-off by the heavy work
+which it throws upon the governor when attached, and the rather
+inflexible character of the device as an expansive valve-gear. The
+best examples of this class of engine have neat heavy bed-plates,
+well-designed cylinders and details, smooth-working valve-gear, the
+expansion-valve adjusted by a right and left hand screw, and
+regulation secured by the attachment of the governor to the
+throttle-valve.
+
+The engine shown in the accompanying illustration (Fig. 95) is an
+example of an excellent British stationary steam-engine. It is simple,
+strong, and efficient. The frame, front cylinder-head, cross-head
+guides, and crank-shaft "plumber-block," are cast in one piece, as has
+so generally been done in the United States for a long time by some of
+our manufacturers. The cylinder is secured against the end of the
+bed-plate, as was first done by Corliss. The crank-pin is set in a
+counterbalanced disk. The valve-gear is simple, and the governor
+effective, and provided with a safety-device to prevent injury by the
+breaking of the governor-belt. An engine of this kind of 10 inches
+diameter of cylinder, 20 inches stroke of piston, is rated by the
+builders at about 25 horse-power; a similar engine 30 inches in
+diameter of cylinder would yield from 225 to 250 horse-power. In
+this example, all parts are made to exact size by gauges standardized
+to Whitworth's sizes.
+
+[Illustration: FIG. 95.--Horizontal Stationary Steam-Engine.]
+
+[Illustration: FIG. 96.--Horizontal Stationary Steam-Engine.]
+
+In American engines (as is seen in Fig. 96), usually, two supports are
+placed--the one under the latter bearing, and the other under the
+cylinder--to take the weight of the engine; and through them it is
+secured to the foundation. As in the vertical engine already
+described, a valve is sometimes used, consisting of two pistons
+connected by a rod, and worked by an ordinary eccentric. By a simple
+arrangement these pistons have always the same pressure inside as out,
+which prevents any leakage or blowing through; and they are said
+always to work equally as well and free from friction under 150 pounds
+pressure as under 10 pounds per square inch, and to require no
+adjustment. It is more usual, however, to adopt the three-ported valve
+used on locomotives, with (frequently) a cut-off valve on the back of
+this main valve, which cut-off valve is adjusted either by hand or by
+the governor.
+
+Engines of the class just described are especially well fitted, by
+their simplicity, compactness, and solidity, to work at the high
+piston-speeds which are gradually becoming generally adopted in the
+effort to attain increased economy of fuel by the reduction of the
+immense losses of heat which occur in the expansion of steam in the
+metallic cylinders through which we are now compelled to work it.
+
+One of the best known of recent engines is the Allen engine, a
+steam-engine having the same general arrangement of parts seen in the
+above illustration, but fitted with a peculiar valve-gear, and having
+proportions of parts which are especially calculated to secure
+smoothness of motion and uniformity of pressure on crank-pin and
+journals, at speeds so high that the inertia of the reciprocating
+parts becomes a seriously-important element in the calculation of the
+distribution of stresses and their effect on the dynamics of the
+machine.
+
+In the Allen engine,[85] the cylinder and frame are connected as in
+the engine seen above, and the crank-disk, shaft-bearings, and other
+principal details, are not essentially different. The valve-gear[86]
+differs in having four valves, one at each end on the steam as well as
+on the exhaust side, all of which are balanced and work with very
+little resistance. These valves are not detachable, but are driven by
+a link attached to and moved by an eccentric on the main shaft, the
+position of the valve-rod attachment to which link is determined by
+the governor, and the degree of expansion is thus adjusted to the work
+of the engine. The engine has usually a short stroke, not exceeding
+twice the diameter of cylinder, and is driven at very high speed,
+generally averaging from 600 to 800 feet per minute.[87] This high
+piston-speed and short stroke give very great velocity of rotation.
+The effect is, therefore, to produce an exceptional smoothness of
+motion, while permitting the use of small fly-wheels. Its short stroke
+enables entire solidity to be attained in a bed of rigid form, making
+it a very completely self-contained engine, adapted to the heaviest
+work, and requiring only a small foundation.
+
+  [85] The invention of Messrs. Charles T. Porter and John F. Allen.
+
+  [86] Invented by Mr. John F. Allen.
+
+  [87] Or not far from 600 times the cube root of the length of
+  stroke, measured in feet.
+
+The journals of the shaft, and all cylindrical wearing surfaces, are
+finished by grinding in a manner that leaves them perfectly round. The
+crank-pin and cross-head pin are hardened before being ground. The
+joints of the valve-gear consist of pins turning in solid ferrules in
+the rod-ends, both hardened and ground. After years of constant use
+thus, no wear occasioning lost time in the valve-movements has been
+detected.
+
+High speed and short strokes are essential elements of economy. It is
+now well understood that all the surfaces with which the steam comes
+in contact condense it.
+
+Obviously, one way to diminish this loss is to reduce the extent of
+surface to which the steam is exposed. In engines of high speed and
+short stroke, the surfaces with which the steam comes in contact,
+while doing a given amount of work, present less area than in ordinary
+engines running at low speed. Where great steadiness of motion is
+desired, the expense of coupled engines is often incurred.
+Quick-running engines do not require to be coupled; a single engine
+may give greater uniformity of motion than is usually obtained with
+coupled engines at ordinary speeds. The ports and valve-movements, the
+weight of the reciprocating parts, and the size and weight of the
+fly-wheels, should be calculated expressly for the speeds chosen.
+
+The economy of the engine here described is unexcelled by the best of
+the more familiar "drop cut-off" engines.
+
+An engine reported upon by a committee of the American Institute, of
+which Dr. Barnard was chairman, was non-condensing, 16 inches in
+diameter of cylinder, 30 inches stroke, making 125 revolutions per
+minute, and developed over 125 horse-power with 75 pounds of steam in
+the boiler, using 25-3/4 pounds of steam per indicated horse-power,
+and 2.87 pounds of coal--an extraordinarily good performance for an
+engine of such small power.
+
+The governor used on this engine is known as the Porter governor. It
+is given great power and delicacy by weighting it down, and thus
+obtaining a high velocity of rotation, and by suspending the balls
+from forked arms, which are given each two bearing-pins separated
+laterally so far as to permit considerable force to be exerted in
+changing speeds without cramping those bearings sufficiently to
+seriously impair the sensitiveness of the governor. This engine as a
+whole may be regarded as a good representative of the high-speed
+engine of to-day.
+
+Since this change in the direction of high speeds has already gone so
+far that the "drop cut-off" is sometimes inapplicable, in consequence
+of the fact that the piston would, were such a valve-gear adopted,
+reach the end of its stroke before the detached valve could reach its
+seat; and since this progress is only limited by our attainments in
+mechanical skill and accuracy, it seems probable that the
+"positive-motion expansion-gear" type of engine will ultimately
+supersede the now standard "drop cut-off engine."
+
+The best known and most generally used class of stationary engines at
+the present time is, however, that which has the so-called "drop
+cut-off," or "detachable valve-gear." The oldest well-known form of
+valve-motion of this description now in use is that known as the
+Sickels cut-off, patented by Frederick E. Sickels, an American
+mechanic, about the year 1841, and also built by Hogg, of New York,
+who placed it upon the engine of the steamer South America. The
+invention is claimed for both Hogg and Sickels. It was introduced by
+the inventor in a form which especially adapted it to use with the
+beam-engine used on the Eastern waters of the United States, and was
+adapted to stationary engines by Messrs. Thurston, Greene & Co., of
+Providence, R. I., who made use of it for some years before any other
+form of "drop cut-off" came into general use. The Sickels cut-off
+consisted of a set of steam-valves, usually independent of the
+exhaust-valves, and each raised by a catch, which could be thrown out,
+at the proper moment, by a wedge with which it came in contact as it
+rose with the opening valve. This wedge, or other equivalent device,
+was so adjusted that the valve should be detached and fall to its seat
+when the piston reached that point in its movement, after taking
+steam, at which expansion was to commence. From this point, no steam
+entering the cylinder, the piston was impelled by the expanding vapor.
+The valve was usually the double-poppet. Sickels subsequently invented
+what was called the "beam-motion," to detach the valve at any point in
+the stroke. As at first arranged, the valve could only be detached
+during the earlier half-stroke, since at mid-stroke the direction of
+motion of the eccentric rod was reversed and the valve began to
+descend. By introducing a "wiper" having a motion transverse to that
+of the valve and its catch, and by giving this wiper a motion
+coincident with that of the piston by connecting it with the beam or
+other part of the engine moving with the piston, he obtained a
+kinematic combination which permitted the valve to be detached at any
+point in the stroke, adding a very simple contrivance which enabled
+the attendant to set the wiper so that it should strike the catch at
+any time during the forward movement of the "beam-motion."
+
+On stationary engines, the point of cut-off was afterward determined
+by the governor, which was made to operate the detaching mechanism,
+the combination forming what is sometimes called an "automatic"
+cut-off. The attachment of the governor so as to determine the degree
+of expansion had been proposed before Sickels's time. One of the
+earliest of these contrivances was that of Zachariah Allen, in 1834,
+using a cut-off valve independent of the steam-valve. The first to so
+attach the governor to a _drop cut-off_ valve-motion was George H.
+Corliss, who made it a feature of the Corliss valve-gear in 1849. In
+the year 1855, N. T. Greene introduced a form of expansion-gear, in
+which he combined the range of the Sickels beam-motion device with the
+expansion-adjustment gained by the attachment of the governor, and
+with the advantages of flat slide-valves at all ports--both steam and
+exhaust.
+
+Many other ingenious forms of expansion valve-gear have been invented,
+and several have been introduced, which, properly designed and
+proportioned to well-planned engines, and with good construction and
+management, should give economical results little if at all inferior
+to those just named. Among the most ingenious of these later devices
+is that of Babcock & Wilcox, in which a very small auxiliary
+steam-cylinder and piston is employed to throw the cut-off valve over
+its port at the instant at which the steam is to be cut off. A very
+beautiful form of isochronous governor is used on this engine, to
+regulate the speed of the engine by determining the point of cut-off.
+
+In Wright's engine, the expansion is adjusted by the movement, by the
+regulator, of cams which operate the steam-valves so that they shall
+hold the valve open a longer or shorter time, as required.
+
+Since compactness and lightness are not as essential as in portable,
+locomotive, and marine engines, the parts are arranged, in stationary
+engines, with a view simply to securing efficiency, and the design is
+determined by circumstances. It was formerly usual to adopt the
+condensing engine in mills, and wherever a stationary engine was
+required. In Europe generally, and to some extent in the United
+States, where a supply of condensing water is obtainable, condensing
+engines and moderate steam-pressures are still employed. But this type
+of engine is gradually becoming superseded by the high-pressure
+condensing engine, with considerable expansion, and with an
+expansion-gear in which the point of cut-off is determined by the
+governor.
+
+[Illustration: FIG. 97.--Corliss Engine.]
+
+[Illustration: FIG. 98--Corliss Engine Valve-Motion.]
+
+The best-known engine of this class is the Corliss engine, which is
+very extensively used in the United States, and which has been copied
+very generally by European builders. Fig. 97 represents the Corliss
+engine. The horizontal steam-cylinder is bolted firmly to the end of
+the frame, which is so formed as to transmit the strain to the main
+journal with the greatest directness. The frame carries the guides for
+the cross-head, which are both in the same vertical plane. The valves
+are four in number, a steam and an exhaust valve being placed at each
+end of the steam-cylinder. Short steam-passages are thus secured, and
+this diminution of clearance is a source of some economy. Both sets of
+valves are driven by an eccentric operating a disk or wrist-plate, _E_
+(Fig. 98), which vibrates on a pin projecting from the cylinder. Short
+links reaching from this wrist-plate to the several valves, _D D_, _F
+F_, move them with a peculiarly varying motion, opening and closing
+them rapidly, and moving them quite slowly when the port is either
+nearly open or almost closed. This effect is ingeniously secured by so
+placing the pins on the wrist-plate that their line of motion becomes
+nearly transverse to the direction of the valve-links when the limit
+of movement is approached. The links connecting the wrist-plate with
+the arms moving the steam-valves have catches at their extremities,
+which are disengaged by coming in contact, as the arm swings around
+with the valve-stem, with a cam adjusted by the governor. This
+adjustment permits the steam to follow the piston farther when the
+engine is caused to "slow down," and thus tends to restore the proper
+speed. It disengages the steam-valve earlier, and expands the steam to
+a greater extent, when the engine begins to run above the proper
+speed. When the catch is thrown out, the valve is closed by a weight
+or a strong spring. To prevent jar when the motion of the valve is
+checked, a "dash-pot" is used, invented originally by F. E. Sickels.
+This is a vessel having a nicely-fitted piston, which is received by a
+"cushion" of water or air when the piston suddenly enters the cylinder
+at the end of the valve-movement. In the original water dash-pot of
+Sickels, the cylinder is vertical, and the plunger or piston descends
+upon a small body of water confined in the base of the dash-pot.
+Corliss's air dash-pot is now often set horizontally.
+
+[Illustration: FIG. 99.--Greene Engine.]
+
+In the Greene steam-engine (Fig. 99), the valves are four in number,
+as in the Corliss. The cut-off gear consists of a bar, _A_, moved by
+the steam-eccentric in a direction parallel with the centre-line of
+the cylinder and nearly coincident as to time with the piston. On this
+bar are tappets, _C C_, supported by springs and adjustable in height
+by the governor, _G_. These tappets engage the arms _B B_, on the ends
+of rock-shafts, _E E_, which move the steam-valves and remain in
+contact with them a longer or shorter time, and holding the valve open
+during a greater or less part of the piston-stroke, as the governor
+permits the tappets to rise with diminishing engine-speed, or forces
+them down as speed increases. The exhaust-valves are moved by an
+independent eccentric rod, which is itself moved by an eccentric set,
+as is usual with the Corliss and with other engines generally, at
+right angles with the crank. This engine, in consequence of the
+independence of the steam-eccentric, and of the contemporary movement
+of steam valve-motion and steam-piston, is capable of cutting off at
+any point from beginning to nearly the end of the stroke. The usual
+arrangement, by which steam and exhaust valves are moved by the same
+eccentric, only permits expansion with the range from the beginning to
+half-stroke. In the Corliss engine the latter construction is
+retained, with the object, in part, of securing a means of closing the
+valve by a "positive motion," should, by any accident, the closing not
+be effected by the weight or spring usually relied upon.
+
+[Illustration: FIG. 100.--Thurston's Greene-Engine Valve-Gear.]
+
+The steam-valve of the Greene engine, as designed by the author, is
+seen in Fig. 100, where the valve, _G H_, covering the port, _D_, in
+the steam-cylinder, _A B_, is moved by the rod, _J J_, connected to
+the rock-shaft, _M_, by the arm, _L K_. The line, _K I_, should, when
+carried out, intersect the valve-face at its middle point, under _G_.
+
+The characteristics of the American stationary engine, therefore, are
+high steam-pressure without condensation, an expansion valve-gear with
+drop cut-off adjustable by the governor, high piston-speed, and
+lightness combined with strength of construction. The pressure most
+commonly adopted in the boilers which furnish steam to this type of
+engine is from 75 to 80 pounds per square inch; but a pressure of 100
+pounds is not infrequently carried, and the latter pressure may be
+regarded as a "mean maximum," corresponding to a pressure of 60 pounds
+at about the commencement of the period here considered--1850.
+
+Very much greater pressures have, however, been adopted by some
+makers, and immensely "higher steam" has been experimented with by
+several engineers. As early as 1823, Jacob Perkins[88] commenced
+experimenting with steam of very great tension. As has already been
+stated, the usual pressure at the time of Watt was but a few pounds--5
+or 7--in excess of that of the atmosphere. Evans, Trevithick, and
+Stevens, had previously worked steam at pressures of from 50 to 75
+pounds per square inch, and pressures on the Western rivers and
+elsewhere in the United States had already been raised to 100 or 150
+pounds, and explosions were becoming alarmingly frequent.
+
+  [88] Perkins was a native of Newburyport, Mass. He was born July 9,
+  1766, and died in London, July 30, 1849. He went to England when
+  fifty-two years of age, to introduce his inventions.
+
+Perkins's experimental apparatus consisted of a copper boiler, of a
+capacity of about one cubic foot, having sides 3 inches in thickness.
+It was closed at the bottom and top, and had five small pipes leading
+from the upper head. This was placed in a furnace kept at a high
+temperature by a forced combustion. Safety-valves loaded respectively
+to 425 and 550 pounds per square inch were placed on each of two of
+the steam-pipes.
+
+Perkins used the steam generated under these great pressures in a
+little engine having a piston 2 inches in diameter and a stroke of 1
+foot. It was rated at 10 horse-power.[89]
+
+  [89] It was when writing of this engine that Stuart wrote, in 1824:
+  "Judging from the rapid strides the steam-engine has made _during
+  the last forty years_ to become a universal first-mover, and from
+  the experience that has arisen from that extension, we feel
+  convinced that every invention which diminishes its size without
+  impairing its power brings it a step nearer to the assistance of the
+  'world's great laborers,' the husbandman and the peasant, for whom,
+  as yet, it performs but little. At present, it is made occasionally
+  to tread out the corn. What honors await not that man who may yet
+  direct its mighty power to plough, to sow, to harrow, and to reap!"
+  The progress of the steam-engine during those forty years does not
+  to-day appear so astounding. The sentiment here expressed has lost
+  none of its truth, nevertheless.
+
+In the year 1827, Perkins had attained working pressures, in a
+single-acting, single-cylinder engine, of upward of 800 pounds per
+square inch. At pressures exceeding 200 pounds, he had much trouble in
+securing effective lubrication, as all oils charred and decomposed at
+the high temperatures then unavoidably encountered, and he finally
+succeeded in evading this seemingly insurmountable obstacle by using
+for rubbing parts a peculiar alloy which required no lubrication, and
+which became so beautifully polished, after some wear, that the
+friction was less than where lubricants were used. At these high
+pressures Perkins seems to have met with no other serious difficulty.
+He condensed the exhaust-steam and returned it to the boiler, but did
+not attempt to create a vacuum in his condenser, and therefore needed
+no air-pump. Steam was cut off at one-eighth stroke.
+
+In the same year, Perkins made a compound engine on the Woolf plan,
+and adopted a pressure of 1,400 pounds, expanding eight times. In
+still another engine, intended for a steam-vessel, Perkins adopted, or
+proposed to adopt, 2,000 pounds pressure, cutting off the admission at
+one-sixteenth, in single-acting engines of 6 inches diameter of
+cylinder and 20 inches stroke of piston. The steam did not retain
+boiler-pressure at the cylinder, and this engine was only rated at 30
+horse-power.[90]
+
+  [90] Galloway and Hebert, on the Steam-Engine. London, 1836.
+
+Stuart follows a description of Perkins's work in the improvement of
+the steam-engine and the introduction of steam-artillery by the
+remark:
+
+" ... No other mechanic of the day has done more to illustrate an
+obscure branch of philosophy by a series of difficult, dangerous,
+and expensive experiments; no one's labors have been more deserving
+of cheering encouragement, and no one has received less. Even in
+their present state, his experiments are opening new fields for
+philosophical research, and his mechanism bids fair to introduce
+a new style into the proportions, construction, and form, of
+steam-machinery."
+
+Perkins's experience was no exception to the general rule, which
+denies to nearly all inventors a fair return for the benefits which
+they confer upon mankind.
+
+Another engineer, a few years later, was also successful in
+controlling and working steam under much higher pressures than are
+even now in use. This was Dr. Ernst Alban, a distinguished German
+engine-builder, of Plau, Mecklenburg, and an admirer of Oliver Evans,
+in whose path he, a generation later, advanced far beyond that great
+pioneer. Writing in 1843, he describes a system of engine and boiler
+construction, with which he used steam under pressures about equal to
+those experimentally worked by Jacob Perkins, Evans's American
+successor. Alban's treatise was translated and printed in Great
+Britain,[91] four years later.
+
+  [91] "The High-Pressure Steam-Engine," etc. By Dr. Ernst Alban.
+  Translated by William Pole, F. R. A. S. London, 1847.
+
+Alban, on one occasion, used steam of 1,000 pounds pressure. His
+boilers were similar in general form to the boiler patented by Stevens
+in 1805, but the tubes were horizontal instead of vertical. He
+evaporated from 8 to 10 pounds of water into steam of 600 to 800
+pounds pressure with each pound of coal. He states that the
+difficulty met by Perkins--the decomposition of lubricants in the
+steam-cylinder--did not present itself in his experiments, even when
+working steam at a pressure of 600 pounds on the square inch, and he
+found that less lubrication was needed at such high pressures than in
+ordinary practice. Alban expanded his steam about as much as Evans, in
+his usual practice, carrying a pressure of 150 pounds, and cutting off
+at one-third; he adopted greatly increased piston-speed, attaining 300
+feet per minute, at a time when common practice had only reached 200
+feet. He usually built an oscillating engine, and rarely attached a
+condenser. The valve was the locomotive-slide.[92] The stroke was made
+short to secure strength, compactness, cheapness, and high speed of
+rotation; but Alban does not seem to have understood the principles
+controlling the form and proportions of the expansive engine, or the
+necessity of adopting considerable expansion in order to secure
+economy in working steam of great tension, and therefore was,
+apparently, not aware of the advantages of a long stroke in reducing
+losses by "dead-space," in reducing risk of annoyance by hot journals,
+or in enabling high piston-speeds to be adopted. He seems never to
+have attained a sufficiently high speed of piston to become aware that
+the oscillating cylinder cannot be used at speeds perfectly
+practicable with the fixed cylinder.
+
+  [92] Invented by Joseph Maudsley, of London, 1827.
+
+Alban states that one of his smallest engines, having a cylinder 4-1/2
+inches in diameter and 1 foot stroke of piston, with a piston-speed of
+but 140 to 160 feet per minute, developed 4 horse-power, with a
+consumption of 5.3 pounds of coal per hour. This is a good result for
+so small an amount of work, and for an engine working at so low a
+speed of piston. An engine of 30 horse-power, also working very
+slowly, required but 4.1 pounds of coal per hour per horse-power.
+
+The work of Perkins and of Alban, like that of their predecessors,
+Evans, Stevens, and Trevithick, was, however, the work of engineers
+who were far ahead of their time. The general practice, up to the time
+which marked the beginning of the modern "period of refinement," had
+been but gradually approximating that just described. Higher pressures
+were slowly approached; higher piston-speeds came slowly into use;
+greater expansion was gradually adopted; the causes of losses of heat
+were finally discovered, and steam-jacketing and external
+non-conducting coverings were more and more generally applied as
+builders became more familiar with their work. The "compound engine"
+was now and then adopted; and each experiment, made with higher steam
+and greater expansion, was more nearly successful than the last.
+
+Finally, all these methods of securing economy became recognized, and
+the reasons for their adoption became known. It then remained, as the
+final step in this progression, to combine all these requisites of
+economical working in a double-cylinder engine, steam-jacketed, well
+protected by non-conducting coverings, working steam of high pressure,
+and with considerable expansion at high piston-speed. This is now done
+by the best builders.
+
+One of the best examples of this type of engine is that constructed by
+the sons of Jacob Perkins, who continued the work of their father
+after his death. Their engines are single-acting, and the small or
+high-pressure cylinder is placed on the top of the larger or
+low-pressure cylinder. The valves are worked by rotating stems, and
+the loss of heat and burning of packing incident to the use of the
+common method are thus avoided. The stuffing-boxes are placed at the
+end of long sleeves, closely surrounding the vertical valve-stems
+also, and the water of condensation which collects in these sleeves is
+an additional and thorough protection against excessively high
+temperature at the packing. The piston-rings are made of the alloy
+which has been found to require no lubrication.
+
+Steam is usually worked at from 250 to 450 pounds, and is generated in
+boilers composed of small tubes three inches in diameter and
+three-eighths of an inch thick, which are tested under a pressure of
+2,500 pounds per square inch. The safety-valve is usually loaded to
+400 pounds. The boiler is fed with distilled water, obtained
+principally by condensation of the exhaust-steam, any deficiency being
+made up by the addition of water from a distilling apparatus. Under
+these conditions, but 1-1/4 pound of coal is consumed per hour and per
+horse-power.
+
+THE PUMPING-ENGINE in use at the present time has passed through a
+series of changes not differing much from that which has been traced
+with the stationary mill-engine. The Cornish engine is still used to
+some extent for supplying water to towns, and is retained at deep
+mines. The modern Cornish engine differs very little from that of the
+time of Watt, except in the proportions of parts and the form of its
+details. Steam-pressures are carried which were never reached during
+the preceding period, and, by careful adjustment of well-set and
+well-proportioned valves and gearing, the engine has been made to work
+rather more rapidly, and to do considerably more work. It still
+remains, however, a large, costly, and awkward contrivance, requiring
+expensive foundations, and demanding exceptional care, skill, and
+experience in management. It is gradually going out of use. This
+engine, as now constructed by good builders, is shown in section in
+Fig. 101.
+
+A comparison with the Watt engine of a century earlier will at once
+enable any one to appreciate the extent to which changes may be made
+in perfecting a machine, even after it has become complete, so far as
+supplying it with all essential parts can complete it.
+
+[Illustration: FIG. 101.--Cornish Pumping-Engine, 1880.]
+
+In the figure, _A_ is the cylinder, taking steam from the boiler
+through the steam-passage, _M_. The steam is first admitted above the
+piston, _B_, driving it rapidly downward and raising the pump-rod,
+_E_. At an early period in the stroke the admission of steam is
+checked by the sudden closing of the induction-valve at _M_, and the
+stroke is completed under the action of expanding steam assisted by
+the inertia of the heavy parts already in motion. The necessary weight
+and inertia is afforded, in many cases, where the engine is applied to
+the pumping of deep mines, by the immensely long and heavy pump-rods.
+Where this weight is too great, it is counterbalanced, and where too
+small, weights are added. When the stroke is completed, the
+"equilibrium valve" is opened, and the steam passes from above to the
+space below the piston, and an equilibrium of pressure being thus
+produced, the pump-rods descend, forcing the water from the pumps and
+raising the steam-piston. The absence of the crank, or other device
+which might determine absolutely the length of stroke, compels a very
+careful adjustment of steam-admission to the amount of load. Should
+the stroke be allowed to exceed the proper length, and should danger
+thus arise of the piston striking the cylinder-head, _N_, the movement
+is checked by buffer-beams. The valve-motion is actuated by a
+plug-rod, _J K_, as in Watt's engine. The regulation is effected by a
+"cataract," a kind of hydraulic governor, consisting of a
+plunger-pump, with a reservoir attached. The plunger is raised by the
+engine, and then automatically detached. It falls with greater or less
+rapidity, its velocity being determined by the size of the
+eduction-orifice, which is adjustable by hand. When the plunger
+reaches the bottom of the pump-barrel, it disengages a catch, a weight
+is allowed to act upon the steam-valve, opening it, and the engine is
+caused to make a stroke. When the outlet of the cataract is nearly
+closed, the engine stands still a considerable time while the plunger
+is descending, and the strokes succeed each other at long intervals.
+When the opening is greater, the cataract acts more rapidly, and the
+engine works faster. This has been regarded until recently as the most
+economical of pumping-engines, and it is still generally used in
+freeing mines of water, and in situations where existing heavy
+pump-rods may be utilized in counterbalancing the steam-pressure, and,
+by their inertia, in continuing the motion after the steam, by its
+expansion, has become greatly reduced in pressure.
+
+In this engine a gracefully-shaped and strong beam, _D_, has taken
+the place of the ruder beam of the earlier period, and is carried on a
+well-built wall of masonry, _R_. _F_ is the exhaust-valve, by which
+the steam passes to the condenser, _G_, beside which is the air-pump,
+_H_, and the hot-well, _I_. The cylinder is steam-jacketed, _P_, and
+protected against losses of heat by radiation by a brick wall, _O_,
+the whole resting on a heavy foundation, _Q_.
+
+The Bull Cornish engine is also still not infrequently seen in use.
+The Cornish engine of Great Britain averages a duty of about
+45,000,000 pounds raised one foot high per 100 pounds of coal. More
+than double this economy has sometimes been attained.
+
+[Illustration: FIG. 102.--Steam-Pump.]
+
+A vastly simpler form of pumping-engine without fly-wheel is the now
+common "direct-acting steam-pump." This engine is generally made use
+of in feeding steam-boilers, as a forcing and fire pump, and wherever
+the amount of water to be moved is not large, and where the pressure
+is comparatively great. The steam-cylinder, _A R_, and feed-pump, _B
+Q_ (Fig. 102), are in line, and the two pistons have usually one rod,
+_D_, in common. The two cylinders are connected by a strong frame,
+_N_, and two standards fitted with lugs carry the whole, and serve as
+a means of bolting the pump to the floor or to its foundation.
+
+The method of working the steam-valve of the modern steam-pump is
+ingenious and peculiar. As shown, the pistons are moving toward the
+left; when they reach the end of their stroke, the face of the piston
+strikes a pin or other contrivance, and thus moves a small auxiliary
+valve, _I_, which opens a port, _E_, and causes steam to be admitted
+behind a piston, or permits steam to be exhausted, as in the figure,
+from before the auxiliary piston, _F_, and the pressure within the
+main steam-chest then forces that piston over, moving the main
+steam-valve, _G_, to which it is attached, admitting steam to the
+left-hand side of the main piston, and exhausting on the right-hand
+side, _A_. Thus the motion of the engine operates its own valves in
+such a manner that it is never liable to stop working at the end of
+the stroke, notwithstanding the absence of the crank and fly-wheel, or
+of independent mechanism, like the cataract of the Cornish engine.
+There is a very considerable variety of pumps of this class, all
+differing in detail, but all presenting the distinguishing feature of
+auxiliary valve and piston, and a connection by which it and the main
+engine each works the valve of the other combination.
+
+[Illustration: FIG. 103.--The Worthington Pumping-Engine, 1876.
+Section.]
+
+[Illustration: FIG. 104.--The Worthington Pumping-Engine.]
+
+In some cases these pumps are made of considerable size, and are
+applied to the elevation of water in situations to which the Cornish
+engine was formerly considered exclusively applicable. The
+accompanying figure illustrates such a pumping-engine, as built for
+supplying cities with water. This is a "compound" direct-acting
+pumping-engine. The cylinders, _A B_, are placed in line, working one
+pump, _F_, and operating their own air-pumps, _D D_, by a bell-crank
+lever, _L H_, connected to the pump-buckets by links, _I K_. Steam
+exhausted from the small cylinder, _A_, is further expanded in the
+large cylinder, _B_, and thence goes to the condenser, _C_. The
+valves, _N M_, are moved by the valve-gear, _L_, which is actuated by
+the piston-rod of a similar pair of cylinders placed by the side of
+the first. These valves are balanced, and the balance-plates, _R Q_,
+are suspended from the rods, _O P_, which allow them to move with the
+valves. By connecting the valves of each engine with the piston-rod
+of the other, it is seen that the two engines must work alternately,
+the one making a stroke while the other is still, and then itself
+stopping a moment while the latter makes its stroke.
+
+Water enters the pump through the induction-pipe, _E_, passes into the
+pump-barrel through the valves, _V V_, and issues through the
+eduction-valves, _T T_, and goes on to the "mains" by the pipe, _G_,
+above which is seen an air-chamber, which assists to preserve a
+uniform pressure on that side the pump. This engine works very
+smoothly and quietly, is cheap and durable, and has done excellent
+duty.
+
+Beam pumping-engines are now almost invariably built with crank and
+fly-wheel, and very frequently are compound engines. The accompanying
+illustration represents an engine of the latter form.
+
+[Illustration: FIG. 105.--Double-Cylinder Pumping-Engine, 1878.]
+
+[Illustration: FIG. 106.--The Lawrence Water-Works Engine.]
+
+_A_ and _B_ are the two steam-cylinders, connected by links and
+parallel motion, _C D_, to the great cast-iron beam, _E F_. At the
+opposite end of the beam, the connecting-rod, _G_, turns a crank,
+_H_, and fly-wheel, _L M_, which regulates the motion of the engine
+and controls the length of stroke, averting all danger of accident
+occurring in consequence of the piston striking either cylinder-head.
+The beam is carried on handsomely-shaped iron columns, which, with
+cylinders, pump, and fly-wheel, are supported by a substantial stone
+foundation. The pump-rod, _I_, works a double-acting pump, _J_, and
+the resistance to the issuing water is rendered uniform by an
+air-chamber, _K_, within which the water rises and falls when
+pressures tend to vary greatly. A revolving shaft, _N_, driven from
+the fly-wheel shaft, carries cams, _O P_, which move the lifting-rods
+seen directly over them and the valves which they actuate. Between the
+steam-cylinders and the columns which carry the beams is a well, in
+which are placed the condenser and air-pump. Steam is carried at 60 or
+80 pounds pressure, and expanded from 6 to 10 times.
+
+[Illustration: FIG. 107.--The Leavitt Pumping-Engine.]
+
+A later form of double-cylinder beam pumping-engine is that invented
+and designed by E. D. Leavitt, Jr., for the Lawrence Water-Works, and
+shown in Figs. 106 and 107. The two cylinders are placed one on each
+side the centre of the beam, and are so inclined that they may be
+coupled to opposite ends of it, while their lower ends are placed
+close together. At their upper ends a valve is placed at each end of
+the connecting steam-pipe. At their lower ends a single valve serves
+as exhaust-valve to the high-pressure and as steam-valve to the
+low-pressure cylinder. The pistons move in opposite directions, and
+steam is exhausted from the high-pressure cylinder directly into the
+nearer end of the low-pressure cylinder. The pump, of the
+"Thames-Ditton" or "bucket-and-plunger" variety, takes a full supply
+of water on the down-stroke, and discharges half when rising and half
+when descending again. The duty of this engine is reported by a board
+of engineers as 103,923,215 foot-pounds for every 100 pounds of coal
+burned. The duty of a moderately good engine is usually considered to
+be from 60 to 70 millions. This engine has steam-cylinders of 17-1/2
+and 36 inches diameter respectively, with a stroke of 7 feet. The pump
+had a capacity of about 195 gallons, and delivered 96 per cent. Steam
+was carried at a pressure of 75 pounds above the atmosphere, and was
+expanded about 10 times. Plain horizontal tubular boilers were used,
+evaporating 8.58 pounds of water from 98 deg. Fahr. per pound of coal.
+
+STEAM-BOILERS.--The steam supplied to the forms of stationary engine
+which have been described is generated in steam-boilers of exceedingly
+varied forms. The type used is determined by the extent to which their
+cost is increased in the endeavor to economize fuel by the pressure of
+steam carried, by the greater or less necessity of providing against
+risk of explosion, by the character of the feed-water to be used, by
+the facilities which may exist for keeping in good repair, and even by
+the character of the men in whose hands the apparatus is likely to be
+placed.
+
+As has been seen, the changes which have marked the growth and
+development of the steam-engine have been accompanied by equally
+marked changes in the forms of the steam-boiler. At first, the same
+vessel served the distinct purposes of steam-generator and
+steam-engine. Later, it became separated from the engine, and was then
+specially fitted to perform its own peculiar functions; and its form
+went through a series of modifications under the action of the causes
+already stated.
+
+When steam began to be usefully applied, and considerable pressures
+became necessary, the forms given to boilers were approximately
+spherical, ellipsoidal, or cylindrical. Thus the boilers of De Caus
+(1615) and of the Marquis of Worcester (1663) were spherical and
+cylindrical; those of Savery (1698) were ellipsoidal and cylindrical.
+After the invention of the steam-engine of Newcomen, the pressures
+adopted were again very low, and steam-boilers were given irregular
+forms until, at the beginning of the present century, they were again
+of necessity given stronger shapes. The material was at first
+frequently copper; it is now usually wrought-iron, and sometimes
+steel.
+
+The present forms of steam-boilers may be classified as plain, flue,
+and tubular boilers. The plain cylindrical or common cylinder boiler
+is the only representative of the first class in common use. It is
+perfectly cylindrical, with heads either flat or hemispherical. There
+is usually attached to the boiler a "steam-drum" (a small cylindrical
+vessel), from which the steam is taken by the steam-pipe. This
+enlargement of the steam-space permits the mist, held in suspension by
+the steam when it first rises from the surface of the water, to
+separate more or less completely before the steam is taken from the
+boiler.
+
+[Illustration: FIG. 108.--Babcock & Wilcox's Vertical Boiler.]
+
+Flue-boilers are frequently cylindrical, and contain one or more
+cylindrical flues, which pass through from end to end, beneath the
+water-line, conducting the furnace-gases, and affording a greater area
+of heating-surface than can be obtained in the plain boiler. They are
+usually from 30 to 48 inches in diameter, and one foot or less in
+length for each inch of diameter. Some are, however, made 100 feet and
+more in length. The boiler is made of iron 1/4 to 3/8 of an inch in
+thickness, with hemispherical or carefully stayed flat heads, and
+without flues. The whole is placed in a brickwork setting. These
+boilers are used where fuel is inexpensive, where the cost of
+repairing would be great, or where the feed-water is impure. A
+cylindrical boiler, having one flue traversing it longitudinally, is
+called a Cornish boiler, as it is generally supposed to have been
+first used in Cornwall. It was probably first invented by Oliver Evans
+in the United States, previous to 1786, at which time he had it in
+use. The flue has usually a diameter 0.5 or 0.6 the diameter of the
+boiler. A boiler containing two longitudinal flues is called the
+Lancashire boiler. This form was also introduced by Oliver Evans. The
+flues have one-third the diameter of the boiler. Several flues of
+smaller diameter are often used, and when a still greater proportional
+area of heating-surface is required, tubes of from 1-1/4 inch to 4 or
+5 inches in diameter are substituted for flues. The flues are usually
+constructed by riveting sheets together, as in making the shell or
+outer portion. They are sometimes welded by British manufacturers, but
+rarely if ever in the United States. Tubes are always "lap-welded" in
+the process of rolling them. Small tubes were first used in the United
+States, about 1785. In portable, locomotive, and marine steam-boilers,
+the fire must be built within the boiler itself, instead of (as in the
+above described stationary boilers) in a furnace of brickwork exterior
+to the boiler. The flame and gases from the furnace or fire-box in
+these kinds of boiler are never led through brick passages en route to
+the chimney, as often in the preceding case, but are invariably
+conducted through flues or tubes, or both, to the smoke-stack. These
+boilers are also sometimes used as stationary boilers. Fig. 108
+represents such a steam-boiler in section, as it is usually exhibited
+in working drawings. Provision is made to secure a good circulation of
+water in these boilers by means of the "baffle-plates," seen in the
+sketch, which compel the water to flow as indicated by the arrows.
+The tubes are frequently made of brass or of copper, to secure rapid
+transmission of heat to the water, and thus to permit the use of a
+smaller area of heating-surface and a smaller boiler. The steam-space
+is made as large as possible, to secure immunity from "priming" or the
+"entrainment" of water with the steam. This type of steam-boiler,
+invented by Nathan Read, of Salem, Mass., in 1791, and patented in
+April of that year, was the earliest of the tubular boilers. In the
+locomotive boiler (Fig. 109), as in the preceding, the characteristics
+are a fire-box at one end of the shell and a set of tubes through
+which the gases pass directly to the smoke-stack. Strength,
+compactness, great steaming capacity, fair economy, moderate cost, and
+convenience of combination with the running parts, are secured by the
+adoption of this form. It is frequently used also for portable and
+stationary engines. It was invented in France by M. Seguin, and in
+England by Booth, and used by George Stephenson at about the same
+time--1828 or 1829.
+
+[Illustration: FIG. 109.--Stationary "Locomotive" Boiler.]
+
+Since the efficiency of a steam-boiler depends upon the extent of
+effective heating-surface per unit of weight of fuel burned in any
+given time--or, ordinarily, upon the ratio of the areas of heating and
+grate surface--peculiar expedients are sometimes adopted, having for
+their object the increase of heating-surface, without change of form
+of boiler and without proportionate increase of cost.
+
+One of these methods is that of the use of Galloway conical tubes
+(Fig. 110). These are very largely used in Great Britain, but are
+seldom if ever seen in the United States. The Cornish boiler, to which
+they are usually applied, consists of a large cylindrical shell, 6
+feet or more in diameter, containing one tube of about one-half as
+great dimensions, or sometimes two of one-third the diameter of the
+shell each. Such boilers have a very small ratio of heating to grate
+surface, and their large tubes are peculiarly liable to collapse. To
+remove these objections, the Messrs. Galloway introduced stay-tubes
+into the flues, which tubes are conical in form, and are set in either
+a vertical or an inclined position, the larger end uppermost. The area
+of heating-surface is thus greatly increased, and, at the same time,
+the liability to collapse is reduced. The same results are obtained by
+another device of Galloway, which is sometimes combined with that just
+described in the same boiler. Several sheets in the flue have
+"pockets" worked into them, which pockets project into the
+flue-passage.
+
+[Illustration: FIG. 110.]
+
+Another device is that of an American engineer, Miller, who surrounds
+the furnace of cylindrical and other boilers with water-tubes. The
+"fuel-economizers" of Greene and others consist of similar collections
+of tubes set in the flues, between the boiler and the chimney.
+
+"_Sectional_" boilers are gradually coming into use with high
+pressures, on account of their greater safety against disastrous
+explosions. The earliest practicable example of a boiler of this class
+was probably that of Colonel John Stevens, of Hoboken, N. J. Dr.
+Alban, who, forty years later, attempted to bring this type into
+general use, and constructed a number of such boilers, did not
+succeed. Their introduction, like that of all radical changes in
+engineering, has been but slow, and it has been only recently that
+their manufacture has become an important branch of industry.
+
+A committee of the American Institute, of which the author was
+chairman, in 1871, examined several boilers of this and the ordinary
+type, and tested them very carefully. They reported that they felt
+"confident that the introduction of this class of steam-boilers will
+do much toward the removal of the cause of that universal feeling of
+distrust which renders the presence of a steam-boiler so objectionable
+in every locality. The difficulties in thoroughly inspecting these
+boilers, in regulating their action, and other faults of the class,
+are gradually being overcome, and the committee look forward with
+confidence to the time when their use will become general, to the
+exclusion of older and more dangerous forms of steam-boilers."
+
+The economical performance of these boilers with a similar ratio of
+heating to grate surface is equal to that of other kinds. In fact,
+they are usually given a somewhat higher ratio, and their economy of
+fuel frequently exceeds that of the other types. Their principal
+defect is their small capacity for steam and water, which makes it
+extremely difficult to obtain steady steam-pressure. Where they are
+employed, the feed and draught should be, if possible, controlled by
+automatic attachments, and the feed-water heated to the highest
+attainable temperature. Their satisfactory working depends, more than
+in other cases, on the ability of the fireman, and can only be secured
+by the exercise of both care and skill.
+
+Many forms of these boilers have been devised. Walter Hancock
+constructed boilers for his steam-carriage of flat plates connected by
+stay-bolts, several such sections composing the boiler; and about the
+same time (1828) Sir Goldsworthy Gurney constructed for a similar
+purpose boilers consisting of a steam and a water reservoir, placed
+one above the other, and connected by triangularly-bent water-tubes
+exposed to the heat of the furnace-gases. Jacob Perkins made many
+experiments looking to the employment of very high steam-pressures,
+and in 1831 patented a boiler of this class, in which the
+heating-surfaces nearest the fire were composed of iron tubes, which
+tubes also served as grate-bars. The steam and water space was
+principally comprised within a comparatively large chamber, of which
+the walls were secured by closely distributed stay-bolts. For
+extremely high pressures, boilers composed only of tubes were used.
+Dr. Ernst Alban described the boiler already referred to, and its
+construction and operation, and stated that he had experimented with
+pressures as high as 1,000 pounds to the square inch.
+
+The Harrison steam-boiler, which has been many years in use in the
+United States, consists of several sections, each of which is made up
+of hollow globes of cast-iron, communicating with each other by necks
+cast upon the spheres, and fitted together with faced joints. Long
+bolts, extending from end to end of each row, bind the spheres
+together. (_See_ Fig. 111.)
+
+[Illustration: FIG. 111.--Harrison's Sectional Boiler.]
+
+An example of another modern type in extensive use is given in Fig.
+112, a semi-sectional boiler, which consists of a series of inclined
+wrought-iron tubes, connected by T-heads, which form the vertical
+water-channels, at each end. The joints are faced by milling them, and
+then ground so perfectly tight that a pressure of 500 pounds to the
+square inch is insufficient to produce leakage. No packing is used.
+The fire is made under the front and higher end of the tubes, and the
+products of combustion pass up between the tubes into a
+combustion-chamber under the steam and water drum; hence they pass
+down between the tubes, then once more up through the space between
+the tubes, and off to the chimney. The steam is taken out at the top
+of the steam-drum near the back end of the boiler. The rapid
+circulation prevents to some extent the formation of deposits or
+incrustations upon the heating-surfaces, sweeping them away and
+depositing them in the mud-drum, whence they are blown out. Rapid
+circulation of water, as has been shown by Prof. Trowbridge, also
+assists in the extraction of the heat from the gases, by the
+presentation of fresh water continually, as well as by the prevention
+of incrustation.
+
+[Illustration: FIG. 112.--Babcock and Wilcox's Sectional Boiler.]
+
+Attempts have been made to adapt sectional boilers to marine engines;
+but very little progress has yet been made in their introduction. The
+Root sectional boiler (Fig. 113), an American design, which is in
+extensive use in the United States and Europe, has also been
+experimentally placed in service on shipboard. Its heating-surface
+consists wholly of tubes, which are connected by a peculiarly formed
+series of caps; the joints are made tight with rubber "grummets."
+
+[Illustration: FIG. 113.--Root Sectional Boiler.]
+
+
+SECTION II.--PORTABLE AND LOCOMOTIVE ENGINES.
+
+Engines and boilers, when of small size, are now often combined in one
+structure which may be readily transported. Where they have a common
+base-plate simply, as in Fig. 114, they are called, usually,
+"semi-portable engines." These little engines have some decided
+advantages. Being attached to one base, the combined engine and boiler
+is easily transported, occupies little space, and may very readily be
+mounted upon wheels, rendering it peculiarly well adapted for
+agricultural purposes.
+
+[Illustration: FIG. 114.--Semi-Portable Engine, 1878.]
+
+The example here shown differs in its design from those usually seen
+in the market. The engine is not fastened to or upon the boiler, and
+is therefore not affected by expansion, nor are the bearings
+overheated by conduction or by ascending heat from the boiler. The
+fly-wheel is at the base, which arrangement secures steadiness at the
+high speed which is a requisite for economy of fuel. The boilers are
+of the upright tubular style, with internal fire-box, and are
+intended to be worked at 150 pounds pressure per inch. They are fitted
+with a baffle-plate and circulating-pipe, to prevent priming, and also
+with a fusible plug, which will melt and prevent the crown-sheet of
+the boiler burning, if the water gets low.
+
+[Illustration: FIG. 115.--Semi-Portable Engine, 1878.]
+
+Another illustration of this form of engine, as built in small sizes,
+is seen below. The peculiarity of this engine is, that the cylinder is
+placed in the top of the boiler, which is upright. By this arrangement
+the engine is constantly drawing from the boiler the hottest and
+driest steam, and there is thus no liability of serious loss by
+condensation, which is rapid, even in a short pipe, when the engine is
+separate from the boiler.
+
+The engine illustrated is rated at 10 horse-power, and makers are
+always expected to guarantee their machines to work up to the rated
+power. The cylinder is 7 by 7 inches, and the main shaft is directly
+over it. On this shaft are three eccentrics, one working the pump, one
+moving the valves, and the third one operating the cut-off. The
+driving-pulley is 20 inches in diameter, and the balance-wheel 30
+inches. The boiler has 15 1-1/4-inch flues. It is furnished with a
+heater in its lower portion. The boiler of this engine is tested up to
+200 pounds, and is calculated to carry 100 pounds working pressure,
+though that is not necessary to develop the full power of the engine.
+The compactness of the whole machine is exceptional. It can be set up
+in a space 5 feet square and 8 feet high. The weight of the 10
+horse-power engine is 1,540 pounds, and of the whole machine 4,890
+pounds, boxed for shipment. Every part of the mechanism usually fits
+and works with the exactness of a gun-lock, as each piece is carefully
+made to gauge.
+
+Portable engines are those which are especially intended to be moved
+conveniently from place to place. The engine is usually attached to
+the boiler, and the feed-pump is generally attached to the engine. The
+whole machine is carried on wheels, and is moved from one place to
+another, usually by horses, but sometimes by its own engine, which is
+coupled by an engaging and disengaging apparatus to the rear-wheels.
+English builders have usually excelled in the construction of this
+class of steam-engine, although it is probable that the best American
+engines are fully equal to them in design, material, and construction.
+
+The later work of the best-known English builders has given economical
+results that have surprised engineers. The annual "shows" of the Royal
+Agricultural Society have elicited good evidence of skill in
+management as well as of excellence of design and construction. Some
+little portable engines have exhibited an economical efficiency
+superior to that of the largest marine engines of any but the compound
+type, and even closely competing with that form. The causes of this
+remarkable economy are readily learned by an inspection of these
+engines, and by observation of the method of managing them at the
+test-trial. The engines are usually very carefully designed. The
+cylinders are nicely proportioned to their work, and their pistons
+travel at high speed. Their valve-gear consists usually of a plain
+slide-valve, supplemented by a separate expansion-slide, driven by an
+independent eccentric, and capable of considerable variation
+in the point of cut-off. This form of expansion-gear is very
+effective--almost as much so as a drop cut-off--at the usual grade of
+expansion, which is not far from four times. The governor is usually
+attached to a throttle-valve in the steam-pipe, an arrangement which
+is not the best possible under variable loads, but which produces no
+serious loss of efficiency when the engine is driven, as at
+competitive trials, under the very uniform load of a Prony strap-brake
+and at very nearly the maximum capacity of the machine. The most
+successful engines have had steam-jacketed cylinders--always an
+essential to maximum economy--with high steam and a considerable
+expansion. The boilers are strongly made, and are, as are also all
+other heated surfaces, carefully clothed with non-conducting material,
+and well lagged over all. The details are carefully proportioned, the
+rods and frames are strong and well secured together, and the bearings
+have large rubbing-surfaces. The connecting-rods are long and
+easy-working, and every part is capable of doing its work without
+straining and with the least friction.
+
+In handling the engines at the competitive trial, most experienced and
+skillful drivers are selected. The difference between the performances
+of the same engine in different hands has been found to amount to from
+10 to 15 per cent., even where the competitors were both considered
+exceptionally skillful men. In manipulating the engine, the fires are
+attended to with the utmost care; coal is thrown upon them at regular
+and frequent intervals, and a uniform depth of fuel and a perfectly
+clean fire are secured. The sides and corners of the fire are looked
+after with especial care. The fire-doors are kept open the least
+possible time; not a square inch of grate-surface is left unutilized,
+and every pound of coal gives out its maximum of calorific power, and
+in precisely the place where it is needed. Feed-water is supplied as
+nearly as possible continuously, and with the utmost regularity. In
+some cases the engine-driver stands by his engine constantly, feeding
+the fire with coal in handfuls, and supplying the water to the heater
+by hand by means of a cup. Heaters are invariably used in such cases.
+The exhaust is contracted no more than is absolutely necessary for
+draught. The brake is watched carefully, lest irregularity of
+lubrication should cause oscillation of speed with the changing
+resistance. The load is made the maximum which the engine is designed
+to drive with economy. Thus all conditions are made as favorable as
+possible to economy, and they are preserved as invariable as the
+utmost care on the part of the attendant can make them.
+
+These trials are usually of only three or five hours' duration, and
+thus terminate before it becomes necessary to clean fires. The
+following are results obtained at the trial of engines which took
+place in July, 1870, at the Oxford Agricultural Fair:
+
+  KEY:
+  A: Number.
+  B: Diameter.
+  C: Stroke.
+  D: Nominal.
+  E: Dynamometric.
+  F: Point of cut off.
+  G: Revolutions per minute.
+  H: Pounds coal per horse-power per hour.
+
+  ---------------+-------------+-----+--------------+------+------+----
+  MAKERS' NAME   | CYLINDERS.  |     | HORSE-POWER. |      |      |
+      AND        +-----+-------+     +-------+------+      |      |
+   RESIDENCE.    |  A  |   B   |  C  |   D   |  E   |  F   |  G   |  H
+  ---------------+-----+-------+-----+-------+------+------+------+----
+                 |     |Inches.| In. |       |      |      |      |
+  Clayton,       |     |       |     |       |      |      |      |
+  Shuttleworth   |  1  | 7     |  12 |   4   | 4.42 |  ... |121.65|3.73
+  & Co., Lincoln |     |       |     |       |      |      |      |
+                 |     |       |     |       |      |      |      |
+  Brown & May,   |     |       |     |       |      |      |      |
+  Devizes        |  1  | 7-3/16|  12 |   4   | 4.19 | 11.48|125.65|4.44
+                 |     |       |     |       |      |      |      |
+  Reading Iron-  |     |       |     |       |      |      |      |
+  Works Company, |  1  | 5-3/4 |  14 |   4   | 4.16 |  ... |145.7 |4.65
+  Reading        |     |       |     |       |      |      |      |
+  ---------------+-----+-------+-----+-------+------+------+------+----
+
+These were horizontal engines, attached to locomotive boilers.
+
+At a similar exhibition held at Bury, in 1867, considerably better
+results even than these were reported, as below, from engines of
+similar size and styles:
+
+  KEY:
+  A: Number.
+  B: Diameter.
+  C: Stroke.
+  D: Nominal.
+  E: Dynamometric.
+  F: Point of cut off.
+  G: Revolutions per minute.
+  H: Pounds coal per horse-power per hour.
+
+  ---------------+-------------+-----+--------------+------+------+----
+  MAKERS' NAME   | CYLINDERS.  |     | HORSE-POWER. |      |      |
+      AND        +-----+-------+     +-------+------+      |      |
+   RESIDENCE.    |  A  |   B   |  C  |   D   |  E   |  F   |  G   |  H
+  ---------------+-----+-------+-----+-------+------+------+------+----
+                 |     |Inches.| In. |       |      |      |      |
+  Clayton,       |     |       |     |       |      |      |      |
+  Shuttleworth   |  1  |10     | 20  |   10  | 11.00| 3.10 | 71.5 | 4.13
+  & Co., Lincoln |     |       |     |       |      |      |      |
+                 |     |       |     |       |      |      |      |
+  Reading Iron-  |     |       |     |       |      |      |      |
+  Works Company, |  1  | 8-5/8 | 20  |   10  | 10.43| 1.4  |109.4 | 4.22
+  Reading        |     |       |     |       |      |      |      |
+  ---------------+-----+-------+-----+-------+------+------+------+----
+
+With all these engines steam-jackets were used; the feed-water was
+highly and uniformly heated by exhaust-steam; the coal was selected,
+finely broken, and thrown on the fire with the greatest care; the
+velocity of the engines, the steam-pressure, and the amount of
+feed-water, were very carefully regulated, and all bearings were run
+quite loose; the engine-drivers were usually expert "jockeys."
+
+The next illustration represents the portable steam-engine as built by
+one of the oldest and most experienced manufacturers of such engines
+in the United States.
+
+In the boilers of these engines the heating-surface is given less
+extent than in the stationary engine-boiler, but much greater than in
+the locomotive, and varies from 10 to 20 square feet per horse-power.
+The boilers are made very strong, to enable them to withstand the
+strains due to the attached engine, which are estimated as equivalent
+to from one-tenth to one-fifth that due to the steam-pressure. The
+boiler is sometimes given even double the strength usual with
+stationary boilers of similar capacity. The engine is mounted, in this
+example, directly over the boiler, and all parts are in sight and
+readily accessible to the engineer.
+
+[Illustration: FIG. 116.--The Portable Steam-Engine, 1878.]
+
+One of these engines, of 20 horse-power, has a steam-cylinder 10
+inches in diameter and 18 inches stroke of piston, making 125
+revolutions per minute, and has 9 square feet of grate-surface and 288
+feet of heating-surface. It weighs about 4-1/2 tons. Steam is carried
+at 125 pounds.
+
+In the class of engines just described, the draught is obtained by the
+blast of the exhaust-steam which is led into the chimney. Such engines
+are now sold at from $120 to $150 per horse-power, according to size
+and quality, the smaller engines costing most. The usual consumption
+of fuel is from 4 to 6 pounds per hour and per horse-power, burning
+from 15 to 20 pounds on each square foot of grate, and each pound
+evaporating about 8 pounds of water. A usual weight is, for the larger
+sizes, 500 pounds per horse-power.
+
+[Illustration: FIG. 117.--The Thrashers' Road-Engine, 1878.]
+
+These engines are sometimes arranged to propel themselves, as in the
+Mills "Thrashers'" road-engine or locomotive, of which the
+accompanying engraving is a good representation. This engine is
+proportioned for hauling a tank containing 10 barrels, or more, of
+water and a grain-separator over all ordinary roads, and to drive a
+thrashing-machine or saw-mill, developing 20 or 25 horse-power. This
+example of the road-engine has a boiler built to work at 250 pounds of
+steam; the engine is designed for a maximum power of 30 horses.
+
+This engine has a balanced valve and automatic cut-off, and is fitted
+with a reversing-gear for use on the road. The driving-wheels are of
+wrought-iron, 56 inches diameter and 8 inches wide, with cast-iron
+driving-arms. Both wheels are drivers on curves as well as on straight
+lines. The engine is guided and fired by one man, and the total weight
+is so small that it will pass safely over any good country bridge. A
+brake is attached, to insure safety when going down-hill. Although
+designed to move at a speed of about three miles per hour, the
+velocity of the piston may be increased so that four miles per hour
+may be accomplished when necessary.
+
+[Illustration: FIG. 118.--Fisher's Steam-Carriage.]
+
+This is an excellent example of this kind of engine as constructed at
+the present time. The strongly-built boiler, with its heater, the
+jacketed cylinder, and light, strong frame of the engine, the steel
+running-gear, the carefully-covered surfaces of cylinder and boiler,
+and excellent proportions of details, are illustrations of good modern
+engineering, and are in curious contrast with the first of the class,
+built a century earlier by Smeaton.
+
+Steam-carriages for passengers are now rarely built. Fig. 118
+represents that designed by Fisher about 1870 or earlier. It was only
+worked experimentally.
+
+[Illustration: FIG. 119.--Road and Farm Locomotive.]
+
+The above is an engraving of a road and farm locomotive as built by
+one of the most successful among several British firms engaged in this
+work.
+
+The capacity of these engines has been determined by experiment by the
+author in the United States, and abroad by several distinguished
+engineers.
+
+The author made a trial of one of these engines at South Orange, N.
+J., to determine its power, speed, and convenience of working and
+man[oe]uvring. The following were the principal dimensions:
+
+  Weight of engine, complete, 5 tons 4 cwt.          11,648 pounds.
+  Steam-cylinder--diameter                                7-3/4 inches.
+  Stroke of piston                                       10 inches.
+  Revolution of crank to one of driving-wheels           17
+  Driving-wheels--diameter                               60 inches.
+      "           breadth of tire                        10 inches.
+      "           weight, each                          450 pounds.
+  Boiler--length over all                                 8 feet.
+    "     diameter of shell                              30 feet.
+    "     thickness of shell                           7/16 inch.
+    "     fire-box sheets, outside, thickness           1/2 inch.
+  Load on driving-wheels, 4 tons 10 cwt.             10,080 pounds.
+
+The boiler was of the ordinary locomotive type, and the engine was
+mounted upon it, as is usual with portable engines.
+
+The steam-cylinder was steam-jacketed, in accordance with the most
+advanced practice here and abroad. The crank-shaft and other
+wrought-iron parts subjected to heavy strains were strong and plainly
+finished. The gearing was of malleableized cast-iron, and all
+bearings, from crank-shaft to driving-wheel, on each side, were
+carried by a single sheet of half-inch plate, which also formed the
+sides of the fire-box exterior.
+
+The following is a summary of the conclusions deduced by the author
+from the trial, and published in the _Journal of the Franklin
+Institute_: A traction-engine may be so constructed as to be easily
+and rapidly man[oe]uvred on the common road; and an engine weighing
+over 5 tons may be turned continuously without difficulty on a circle
+of 18 feet radius, or even on a road but little wider than the length
+of the engine. A locomotive of 5 tons 4 hundredweight has been
+constructed, capable of drawing on a good road 23,000 pounds up a
+grade of 533 feet to the mile, at the rate of four miles an hour; and
+one might be constructed to draw more than 63,000 pounds up a grade of
+225 feet to the mile, at the rate of two miles an hour.
+
+It was further shown that the coefficient of traction with
+heavily-laden wagons on a good macadamized road is not far from .04;
+the traction-power of this engine is equal to that of 20 horses; the
+weight, exclusive of the weight of the engine, that could be drawn on
+a level road, was 163,452 pounds; and the amount of fuel required is
+estimated at 500 pounds a day. The advantages claimed for the
+traction-engine over horse-power are: no necessity for a limitation of
+working-hours; a difference in first cost in favor of steam; and in
+heavy work on a common road the expense by steam is less than 25 per
+cent. of the average cost of horse-power, a traction-engine capable of
+doing the work of 25 horses being worked at as little expense as 6 or
+8 horses. The cost of hauling heavy loads has been estimated at 7
+cents per ton per mile.
+
+Such engines are gradually becoming useful in steam-ploughing. Two
+systems are adopted. In the one the engine is stationary, and hauls a
+"gang" of ploughs by means of a windlass and wire rope; in the other
+the engine traverses a field, drawing behind it a plough or a gang of
+ploughs. The latter method has been proposed for breaking up
+prairie-land.
+
+Thus, thirty years after the defeat of the intelligent, courageous,
+and persistent Hancock and his coworkers in the scheme of applying the
+steam-engine usefully on the common road, we find strong indications
+that, in a new form, the problem has been again attacked, and at least
+partially solved.
+
+One of the most important of the prerequisites to ultimate success in
+the substitution of steam for animal power on the highway is that our
+roads shall be well made. As the greatest care and judgment are
+exercised, and an immense outlay of capital is considered justifiable,
+in securing easy grades and a smooth track on our railroad routes, we
+may readily believe that similar precaution and outlay will be found
+advisable in adapting the common road to the road-locomotive. It would
+seem to the engineer that the natural obstacles generally supposed to
+stand in the way have, after all, no real existence. The principal
+inconvenience that may be anticipated will probably arise from the
+carelessness or avarice of proprietors, which may sometimes cause them
+to appoint ignorant and inefficient engine-drivers, giving them charge
+of what are always excellent servants, but terrible masters.
+Nevertheless, as the transportation of passengers on railroads is
+found to be attended with less liability to loss of life or injury of
+person than their carriage by stage-coach, it will be found, very
+probably, that the general use of steam in transporting freight on
+common roads may be attended with less risk to life or property than
+to-day attends the use of horse-power.
+
+The STEAM FIRE-ENGINE is still another form of portable engine. It is
+also one of the latest of all applications of steam-power. The steam
+fire-engine is peculiarly an American production. Although previously
+attempted, their permanently successful introduction has only occurred
+within the last fifteen years.
+
+[Illustration: FIG. 120.--The Latta Steam Fire-Engine.]
+
+As early as 1830, Braithwaite and Ericsson, of London, England, built
+an engine with steam and pump cylinders of 7 and 6-1/2 inches
+diameter, respectively, with 16 inches stroke of piston. This machine
+weighed 2-1/2 tons, and is said to have thrown 150 gallons of water
+per minute to a height of between 80 and 100 feet. It was ready for
+work in about 20 minutes after lighting the fire. Braithwaite
+afterward supplied a more powerful engine to the King of Prussia, in
+1832. The first attempt made in the United States to construct a steam
+fire-engine was probably that of Hodge, who built one in New York in
+1841. It was a strong and very effective machine, but was far too
+heavy for rapid transportation. The late J. K. Fisher, who throughout
+his life persistently urged the use of steam-carriages and
+traction-engines, designing and building several, also planned a
+steam fire-engine. Two were built from his design by the Novelty
+Works, New York, about 1860, for Messrs. Lee & Larned. They were
+"self-propellers," and one of them, built for the city of
+Philadelphia, was sent to that city over the highway, driven by its
+own engines. The other was built for and used by the New York Fire
+Department, and did good service for several years. These engines were
+heavy, but very powerful, and were found to move at good speed under
+steam and to man[oe]uvre well. The Messrs. Latta, of Cincinnati, soon
+after succeeded in constructing comparatively light and very effective
+engines, and the fire department of that city was the first to adopt
+steam fire-engines definitely as their principal reliance. This change
+has now become general.
+
+The steam fire-engine has now entirely displaced the old hand-engine
+in all large cities. It does its work at a fraction of the cost of the
+latter. It can force its water to a height of 225 feet, and to a
+distance of more than 300 feet horizontally, while the hand-engine can
+seldom throw it one-third these distances; and the "steamer" may be
+relied upon to work at full power many hours if necessary, while the
+men at the hand-engine soon become fatigued, and require frequent
+relief. The city of New York has 40 steam fire-engines. One engine to
+every 10,000 inhabitants is a proper proportion.
+
+In the standard steam fire-engine (Fig. 120) reciprocating engines and
+pumps are adopted, as seen in section in Fig. 121, in which _A_ is the
+furnace, and _B_ the set of closely-set vertical fire-tubes in the
+boiler. _C_ is the combustion-chamber, _D_ the smoke-pipe, and _R_ the
+steam-space. _E_ is the steam-cylinder, and _F_ the pump, which is
+seen to be double-acting. There are two pairs of engines and pumps,
+working on cranks, set at right angles, and turning a balance-wheel
+seen behind them. _G_ is the feed-pump which supplies water to the
+boiler, _H_ the air-chamber which equalizes the water-pressure, which
+reaches it through the pipe, _I J_. _K_ is the feed-water tank, under
+the driver's seat, _L_, which, with the engines and boiler, are
+carried on the frame, _M M_. The fireman stands on the platform, _N_.
+When it is necessary to move the machine, an endless chain connects
+the crank-shaft with the rear-wheels, and the engine, with pumps shut
+off, is thus made to drive the wheels at any desired speed.
+
+[Illustration: FIG. 121.--The Amoskeag Engine. Section.]
+
+[Illustration: FIG. 122.--The Silsby Rotary Steam Fire-Engine.]
+
+A self-propelling engine by the Amoskeag Company had the following
+dimensions and performance: Weight, 4 tons; speed, 8 miles per hour;
+steam-pressure, 75 pounds per square inch; height of stream from
+1-1/4-inch nozzle, 225 feet; 1-3/4-inch nozzle, 150 feet; distance
+horizontally, 1-1/4-inch nozzle, 300 feet; 1-3/4-inch, 250 feet--a
+performance which contrasts wonderfully with that of the hand-worked
+fire-engine which these engines have now superseded.
+
+It has recently become common to construct the steam fire-engine with
+rotary engine and pump (Fig. 122). The superiority of a rotary motion
+for a steam-engine is apparently so evident that many attempts have
+been made to overcome the practical difficulties to which it is
+subject. One of these difficulties, and the principal one, has been
+the packing of the part which performs the office of the piston in the
+straight cylinder. Robert Stephenson once expressed the opinion that a
+rotary engine would never be made to work successfully, on account of
+this difficulty of packing. The most palpable of the advantages of the
+rotary engine are the reduction in the size of the engine, claimed to
+result from the great velocity of the piston; the avoidance of great
+accidental strains, especially noticed in propelling ships; and a
+great saving of the power which is asserted to be expended in the
+reciprocating engine in overcoming the inertia while changing the
+direction of the motions. These advantages adapt the rotary engine, in
+an especial manner, to the driving of a locomotive or steam
+fire-engine.
+
+[Illustration: FIG. 123.--Rotary Steam-Engine.]
+
+[Illustration: FIG. 124.--Rotary Pump.]
+
+In the Holly rotary engine, seen in Fig. 123, eccentrics and
+sliding-cams, which are frequently used in rotary engines, and which
+are objectionable on account of their great friction, are avoided.
+Corrugated pistons, or irregular cams, _C D_, are adopted, forming
+chambers within the cases. In the engine the steam enters at _A_, at
+the bottom of the case, and presses the cams apart. The only packing
+used is in the ends of the long metal cogs, which are ground to fit
+the case and are kept out by the momentum of the cams, assisted by a
+slight spring back of the packing-pieces. The friction on the pump
+(Fig. 124) is said to be less than in the engine. This is the reason
+given in support of the claim that the rotary engine forces water to a
+given distance with from one-fourth to one-third the steam-pressure
+necessary to drive all reciprocating engines. The smaller amount of
+power necessary to do the work, the less strain and consequent wear
+and tear upon the whole machine, are said to make it more durable and
+reliable. The pump being chambered, its liability to injury by the use
+of dirty or gritty water is lessened, and it is stated that it will
+last for years, pumping gritty water that would soon cut out a
+piston-pump. The pump used with this engine is, as shown in the above
+illustration, somewhat similar to the rotary engine driving it. Each
+of the revolving pistons has three long teeth bearing against the
+cylinder, and packed, to prevent leakage, like the engine-cams. They
+are carried on steel shafts coupled to the engine-shafts. The water
+enters at _E_ and is discharged at _F_, and the passages are purposely
+made large in order that sand, chips, and dirt, which may enter with
+the water, may pass through.
+
+The rotary engine is gradually coming into use for various special
+purposes, where small power is called for, and where economy of fuel
+is not important; but it has never yet competed, and may perhaps never
+in the future compete, with the reciprocating-piston engine where
+large engines are required, or where even moderate economy of fuel is
+essential. This form of engine has assumed so little importance, in
+fact, in the application of the steam-engine, that comparatively
+little is known of its history. Watt invented a rotary engine, and
+Yule many years afterward (1836) constructed such engines at Glasgow.
+Lamb patented another in 1842, Behrens still another in 1847. Napier,
+Hall, Massey, Holly, La France, and others, have built engines of this
+class in later times. Nearly all consist either of cams rotating in
+gear, as in those above sketched, or of a piston set radially in a
+cylinder of small diameter, which turns on its axis within a much
+larger cylinder set eccentrically, the piston, as the former turns,
+sliding in and out of the smaller cylinder as its outer edge slides in
+contact with the inner surface of the larger. In some forms of rotary
+engine, a piston revolves on a central shaft, and a sliding abutment
+in the external cylinder serves to separate the steam from the exhaust
+side and to confine the steam expanding while doing work. Nearly all
+of these combinations are also used as pumps.
+
+Fire-engines, made by the best-known American builders of engines,
+with reciprocating engines and pumps, such as are in general use in
+the United States, have become standard in general plan and
+arrangement of details. These are probably the best illustrations of
+extreme lightness, combined with strength of parts and working power,
+which have ever been produced in any branch of mechanical
+engineering. By using a small boiler crowded with heating-surface,
+very carefully proportioned and arranged, and with small water-spaces;
+by adopting steel for running-gear and working parts wherever
+possible; by working at high piston-speed and with high
+steam-pressure; by selecting fuel with extreme care--by all these
+expedients, the steam fire-engine has been brought, in this country,
+to a state of efficiency far superior to anything seen elsewhere.
+Steam is raised with wonderful promptness, even from cold water, and
+water is thrown from the nozzle at the end of long lines of hose to
+great distances. But this combination of lightness with power is only
+attained at the expense of a certain regularity of action which can
+only be secured by greater water and steam capacity in the boiler. The
+small quantity of water contained within the boiler makes it necessary
+to give constant attention to the feed, and the tendency, almost
+invariably observed, to serious foaming and priming not only compels
+unintermitted care while running, but even introduces an element of
+danger which is not to be despised, even though the machine be in
+charge of the most experienced and skillful attendants. Even the
+greatest care, directed by the utmost skill, would not avail to
+prevent frequent explosions, were it not for the fact that it rarely,
+if ever, happens that accidents to such boilers occur from low water,
+unless the boiler is actually completely emptied of water. In driving
+them at fires, they frequently foam so violently that it is utterly
+impossible to obtain any clew to the amount of water present, and the
+attendant usually keeps his feed-pump on and allows the foaming to go
+on. As long as water is passing into the boiler it is very unlikely
+that any portion will become overheated and that accident will occur.
+Such management appears very reckless, and yet accident from such a
+cause is exceedingly rare.
+
+The changes which have been made in LOCOMOTIVE-CONSTRUCTION during the
+past few years have also been in the direction of the refinement of
+the earlier designs, and have been accompanied by corresponding
+changes in all branches of railroad-work. The adjustment of parts to
+each other and proportioning them to their work, the modification of
+the minor details to suit changes of general dimensions, the
+improvement of workmanship, and the use of better material, have
+signalized this latest period. Special forms of engine have been
+devised for special kinds of work. Small, light tank-engines (Fig.
+125), carrying their own fuel and water without "tenders," are used
+for moving cars about terminal stations and for making up trains;
+powerful, heavy, slow-moving engines, of large boiler-capacity and
+with small wheels, are used on steep gradients and for hauling long
+trains laden with coal and heavy merchandise; and hardly less powerful
+but quite differently proportioned "express"-engines are used for
+passenger and mail service.
+
+[Illustration: FIG. 125.--Tank-Engine, New York Elevated Railroad.]
+
+[Illustration: FIG. 126.--Forney's Tank-Locomotive.]
+
+A peculiar form of engine (Fig. 126) has been designed by Forney, in
+which the whole weight of engine, tender, coal, and water, is carried
+by one frame and on one set of wheels, the permanent weight falling on
+the driving-wheels and the variable load on the truck. These engines
+have also a comparatively short wheel-base and high pulling-power. The
+lightest tank-engines of the first class mentioned weigh 8 or 10 tons;
+but engines much lighter than these, even, are built for mines, where
+they are sent into the galleries to bring out the coal-laden wagons.
+The heaviest engines of this class attain weights of 20 or 30 tons.
+The heaviest engine yet constructed in the United States is said to be
+one in use on the Philadelphia & Reading Railroad, having a weight of
+about 100,000 pounds, which is carried on 12 driving-wheels.
+
+[Illustration: FIG. 127.--British Express Engine.]
+
+[Illustration: FIG. 128.--The Baldwin Locomotive. Section.]
+
+[Illustration: FIG. 129.--The American Type of Express-Engine, 1878.]
+
+A locomotive has two steam-cylinders, either side by side within the
+frame, and immediately beneath the forward end of the boiler, or on
+each side and exterior to the frame. The engines are non-condensing,
+and of the simplest possible construction. The whole machine is
+carried upon strong but flexible steel springs. The steam-pressure is
+usually more than 100 pounds. The pulling-power is generally about
+one-fifth the weight under most favorable conditions, and becomes as
+low as one-tenth on wet rails. The fuel employed is wood in new
+countries, coke in bituminous coal districts, and anthracite coal in
+the eastern part of the United States. The general arrangement and the
+proportions of locomotives differ somewhat in different localities.
+In Fig. 127, a British express-engine, _O_ is the boiler, _N_ the
+fire-box, _X_ the grate, _G_ the smoke-box, and _P_ the chimney. _S_
+is a spring and _R_ a lever safety-valve, _T_ is the whistle, _L_ the
+throttle or regulator valve, _E_ the steam-cylinder, and _W_ the
+driving-wheel. The force-pump, _B C_, is driven from the cross-head,
+_D_. The frame is the base of the whole system, and all other parts
+are firmly secured to it. The boiler is made fast at one end, and
+provision is made for its expansion when heated. Adhesion is
+secured by throwing a proper proportion of the weight upon the
+driving-wheel, _W_. This is from about 6,000 pounds on standard
+freight-engines, having several pairs of drivers, to 10,000 pounds on
+passenger-engines, per axle. The peculiarities of the American type
+(Fig. 128) are the truck, _I J_, or bogie, supporting the forward part
+of the engine, the system of equalizers, or beams which distribute the
+weight of the machine equally over the several axles, and minor
+differences of detail. The cab or house, _r_, protecting the
+engine-driver and fireman, is an American device, which is gradually
+coming into use abroad also. The American locomotive is distinguished
+by its flexibility and ease of action upon even roughly-laid roads. In
+the sketch, which shows a standard American engine in section, _A B_
+is the boiler, _C_ one of the steam-cylinders, _D_ the piston, _E_ the
+cross-head, connected to the crank-shaft, _F_, by the connecting-rod,
+_G H_ the driving-wheels, _I J_ the truck-wheels, carrying the truck,
+_K L_; _N N_ is the fire-box, _O O_ the tubes, of which but four are
+shown. The steam-pipe, _R S_, leads the steam to the valve-chest, _T_,
+in which is seen the valve, moved by the valve-gear, _U V_, and the
+link, _W_. The link is raised or depressed by a lever, _X_, moved from
+the cab. The safety-valve is seen at the top of the dome, at _Y_, and
+the spring-balance by which the load is adjusted is shown at _Z_. At
+_a_ is the cone-shaped exhaust-pipe, by which a good draught is
+secured. The attachments _b_, _c_, _d_, _e_, _f_, _g_--whistle,
+steam-gauge, sand-box, bell, head-light, and "cow-catcher"--are nearly
+all peculiar, either in construction or location, to the American
+locomotive. The cost of passenger-locomotives of ordinary size is
+about $12,000; heavier engines sometimes cost $20,000. The locomotive
+is usually furnished with a tender, which carries its fuel and water.
+The standard passenger-engine on the Pennsylvania Railroad has four
+driving-wheels, 5-1/2 feet diameter; steam-cylinders, 17 inches
+diameter and 2 feet stroke; grate-surface 15-1/2 square feet, and
+heating-surface 1,058 square feet. It weighs 63,100 pounds, of which
+39,000 pounds are on the drivers and 24,100 on the truck. The
+freight-engine has six driving-wheels, 54-5/8 inches in diameter. The
+steam-cylinders are 18 inches in diameter, stroke 22 inches,
+grate-surface 14.8 square feet, heating-surface 1,096 feet. It weighs
+68,500 pounds, of which 48,000 are on the drivers and 20,500 on the
+truck. The former takes a train of five cars up an average grade of 90
+feet to the mile. The latter is attached to a train of 11 cars. On a
+grade of 50 feet to the mile, the former takes 7 and the latter 17
+cars. Tank-engines for very heavy work, such as on grades of 320 feet
+to the mile, which are found on some of the mountain lines of road,
+are made with five pairs of driving-wheels, and with no truck. The
+steam-cylinders are 20-1/8 inches in diameter, 2 feet stroke;
+grate-area, 15-3/4 feet; heating-surface, 1,380 feet; weight with tank
+full, and full supply of wood, 112,000 pounds; average weight, 108,000
+pounds. Such an engine has hauled 110 tons up this grade at the speed
+of 5 miles an hour, the steam-pressure being 145 pounds. The adhesion
+was about 23 per cent. of the weight.
+
+In checking a train in motion, the inertia of the engine itself
+absorbs a seriously large portion of the work of the brakes. This is
+sometimes reduced by reversing the engine and allowing the
+steam-pressure to act in aid of the brakes. To avoid injury by
+abrasion of the surfaces of piston, cylinder, and the valves and
+valve-seats, M. Le Chatelier introduces a jet of steam into the
+exhaust-passages when reversing, and thus prevents the ingress of
+dust-laden air and the drying of the rubbing surfaces. This method of
+checking a train is rarely resorted to, however, except in case of
+danger. The introduction of the "continuous" or "air" brake, which can
+be thrown into action in an instant on every car of the train by the
+engine-driver, is so efficient that it is now almost universally
+adopted. It is one of the most important safeguards which American
+ingenuity has yet devised. In drawing a train weighing 150 tons at the
+rate of 60 miles an hour, about 800 effective horse-power is required.
+A speed of 80 miles an hour has been often attained, and 100 miles has
+probably been reached.
+
+The American locomotive-engine has a maximum life which may be stated
+at about 30 years. The annual cost of repairs is from 10 to 15 per
+cent. of its first cost. On moderately level roads, the engine
+requires a pint of oil to each 25 miles, and a ton of coal to each 40
+or 50 miles run. One of the best-managed railroads in the United
+States reports expenses as follows for one month:
+
+  Number "train-miles" run per ton of coal burned    53.95
+    "         "         "   "  quart of oil used     34.44
+  Passenger-cars hauled 1 mile per ton of coal      275.7
+  Other      "     "      "       "        "        634.8
+  Cost repairs per mile run                          $2 43
+   "   fuel       "      "                            3 64
+   "   oil and waste per mile run                       62
+   "   wages of engine-men per mile run               6 22
+  All other expenses per mile                         1 91
+  Total cost per "train-mile" run                    14 82
+
+Although the above sketch and description represent the construction
+and performance of the standard locomotive of the present time, there
+are indications that the compound arrangement of engines will
+ultimately be adopted. This will involve a considerable change of
+proportions, greatly increasing the volume and weight of
+steam-cylinders, but enabling the designer to more than proportionally
+decrease the weight of boiler and the quantity of fuel carried. There
+is no serious objection to their use, however, and no insuperable
+difficulty in the construction of the "double-cylinder" type of engine
+for the locomotive. A few such engines have already been put in
+service. In these engines the high-pressure cylinder is placed on one
+side and the larger low-pressure cylinder on the other side of the
+locomotive, thus having but two cylinders, as in the older plan. The
+valve-gear is the Stephenson link, as in the ordinary engine. At
+starting, the steam is allowed to act on both pistons; but after a few
+revolutions the course of the steam is changed, and the exhaust from
+the smaller cylinder, instead of passing into the chimney, is sent to
+the larger cylinder, which is at the same time cut off from the main
+steam-pipe. When the engine is ascending a steep gradient the steam
+may, if necessary, be taken from the boiler into both cylinders, as
+when starting. Compound engines of this kind have been used on the
+French line of railroad from Bayonne to Biarritz. They were designed
+by Mallet and built at Le Creuzot. The steam-cylinders are of 9-1/2
+and 15-3/4 inches diameter, and of 17-3/4 inches stroke of piston. The
+four driving-wheels are 4 feet in diameter, and the total weight of
+engine is 20 tons. The boiler has 484-1/2 square feet of
+heating-surface, and is built to carry 10 atmospheres pressure. When
+hauling trains of 50 tons at 25 miles an hour, these engines require
+about 15 pounds of good coal per mile.
+
+The total length of the railways in operation in the United States on
+the 1st day of January, 1877, was 76,640 miles,[93] being an average
+of one mile of railway for every 600 inhabitants. The railways are as
+follows:
+
+  [93] January, 1884, over 120,000 miles.
+
+                     Miles.
+
+  Alabama             1,722
+  Alaska                  0
+  Arizona                 0
+  Arkansas              787
+  California          1,854
+  Colorado              950
+  Connecticut           925
+  Dakota                290
+  Delaware              285
+  Florida               484
+  Georgia             2,308
+  Idaho                   0
+  Illinois            6,980
+  Indiana             4,072
+  Indian Territory      281
+  Iowa                3,937
+  Kansas              3,226
+  Kentucky            1,464
+  Louisiana             539
+  Maine                 987
+  Maryland            1,092
+  Massachusetts       1,825
+  Michigan            3,437
+  Minnesota           2,024
+  Mississippi         1,028
+  Missouri            3,016
+  Montana                 0
+  Nebraska            1,181
+  Nevada                714
+  New Hampshire         942
+  New Jersey          1,594
+  New Mexico              0
+  New York            5,520
+  North Carolina      1,371
+  Ohio                4,680
+  Oregon                251
+  Pennsylvania        5,896
+  Rhode Island          182
+  South Carolina      1,352
+  Tennessee           1,638
+  Texas               2,072
+  Utah                  486
+  Vermont               810
+  Virginia            1,648
+  Washington            110
+  West Virginia         576
+  Wisconsin           2,575
+  Wyoming               459
+                     ------
+    Total            76,640
+
+In 1873 came the great financial crisis, with its terrible results of
+interrupted production, poverty, and starvation, and an almost total
+cessation of the work of building new railroads. The largest number of
+miles ever built in any one year were constructed in 1872. The
+greatest mileage is in Illinois, reaching 6,589; the smallest in Rhode
+Island, 136, and in Washington Territory, 110. The State of
+Massachusetts has one mile of railroad to 4.86 miles of territory,
+this ratio being the greatest in the country. The longest road in
+operation is the Chicago & Northwestern, extending 1,500 miles; the
+shortest, the Little Saw-Mill Run Road in Pennsylvania, which is but
+three miles in length. The total capital of railways in the country is
+$6,000,000,000, or an average of $100,000 per mile. The earnings for
+the year 1872 amounted to $454,969,000, or $7,500 per mile. The
+largest net earnings recorded as made on any road were gained by the
+New York Central & Hudson River, $8,260,827; the smallest on several
+roads which not only earned nothing, but incurred a loss.
+
+The catastrophe of 1873-'74 revealed the fact that the latter
+condition of railroad finances was vastly more common than had been
+suspected; and it is still doubtful whether the existing immense
+network of railroads which covers the United States can be made, as a
+whole, to pay even a moderate return on the money invested in their
+construction. At the period of maximum rate of extension of railroads
+in the United States--1873--the reported lengths of the railroads of
+Europe and America were as follows:[94]
+
+  [94] _Railroad Gazette._
+
+              RAILROADS IN EUROPE AND AMERICA IN 1873.
+
+  ----------------------------+------------+-------------+------------
+       COUNTRIES.             | Railroads, | Population. |   Area,
+                              |   Miles.   |             | Sq. Miles.
+  ----------------------------+------------+-------------+------------
+  United States               |  71,565    |  40,232,000 | 2,492,316
+  Germany                     |  12,207    |  40,111,265 |   212,091
+  Austria                     |   5,865    |  35,943,592 |   227,234
+  France                      |  10,333    |  36,469,875 |   201,900
+  Russia in Europe            |   7,044    |  71,207,794 | 1,992,574
+  Great Britain, 1872         |  15,814    |  31,817,108 |   120,769
+  Belgium                     |   1,301    |   4,839,094 |    11,412
+  Netherlands                 |     886    |   3,858,055 |    13,464
+  Switzerland                 |     820    |   2,669,095 |    15,233
+  Italy                       |   3,667    |  26,273,776 |   107,961
+  Denmark                     |     420    |   1,784,741 |    14,453
+  Spain                       |   3,401    |  16,301,850 |   182,758
+  Portugal                    |     453    |   3,987,867 |    36,510
+  Sweden and Norway           |   1,049    |   5,860,122 |   188,771
+  Greece                      |     100    |   1,332,508 |    19,941
+  ----------------------------+------------+-------------+------------
+
+The railroads in Great Britain comprise over 15,000 miles of track now
+being worked in the United Kingdom, on which have been expended
+$2,800,000,000. This sum is equal to five times the amount of the
+annual value of all the real property in Great Britain, and two-thirds
+of the national debt. After deducting all the working expenses, the
+gross net annual revenue of all the roads exceeds by $110,000,000 the
+total revenue from all sources of Belgium, Holland, Portugal, Denmark,
+Sweden and Norway. An army of 100,000 officers and servants is in the
+employ of the companies, and the value of the rolling-stock exceeds
+$150,000,000.
+
+
+SECTION III.--MARINE ENGINES.
+
+The changes which have now become completed in the marine steam-engine
+have been effected at a later date than those which produced the
+modern locomotive. On the American rivers the modification of the
+beam-engine since the time of Robert L. Stevens has been very slight.
+The same general arrangement is retained, and the details are little,
+if at all, altered. The pressure of steam is sometimes as high as 60
+pounds per square inch.
+
+[Illustration: FIG. 130.--Beam-Engine.]
+
+The valves are of the disk or poppet variety, rising and falling
+vertically. They are four in number, two steam and two exhaust valves
+being placed at each end of the steam-cylinder. The beam-engine is a
+peculiarly American type, seldom if ever seen abroad. Fig. 130 is an
+outline sketch of this engine as built for a steamer plying on the
+Hudson River. This class of engine is usually adopted in vessels of
+great length, light draught, and high speed. But one steam-cylinder is
+commonly used. The cross-head is coupled to one end of the beam by
+means of a pair of links, and the motion of the opposite end of the
+beam is transmitted to the crank by a connecting-rod of moderate
+length. The beam has a cast-iron centre surrounded by a wrought-iron
+strap of lozenge shape, in which are forged the bosses for the
+end-centres, or for the pins to which the connecting-rod and the links
+are attached. The main centre of the beam is supported by a
+"gallows-frame" of timbers so arranged as to receive all stresses
+longitudinally. The crank and shaft are of wrought-iron. The
+valve-gear is usually of the form already mentioned as the Stevens
+valve-gear, the invention of Robert L. and Francis B. Stevens. The
+condenser is placed immediately beneath the steam-cylinder. The
+air-pump is placed close beside it, and worked by a rod attached to
+the beam. Steam-vessels on the Hudson River have been driven by such
+engines at the rate of 20 miles an hour. This form of engine is
+remarkable for its smoothness of operation, its economy and
+durability, its compactness, and the latitude which it permits in the
+change of shape of the long, flexible vessels in which it is generally
+used, without injury by "getting out of line."
+
+[Illustration: FIG. 131.--Oscillating Engine and Feathering
+Paddle-Wheel.]
+
+For paddle-engines of large vessels, the favorite type, which has been
+the side-lever engine, is now rarely built. For smaller vessels, the
+oscillating engine with feathering paddle-wheels is still largely
+employed in Europe. This style of engine is shown in Fig. 131. It is
+very compact, light, and moderately economical, and excels in
+simplicity. The usual arrangement is such that the feathering-wheel
+has the same action upon the water as a radial wheel of double
+diameter. This reduction of the diameter of the wheel, while retaining
+maximum effectiveness, permits a high speed of engine, and therefore
+less weight, volume, and cost. The smaller wheel-boxes, by offering
+less resistance to the wind, retard the progress of the vessel less
+than those of radial wheels. Inclined engines are sometimes used for
+driving paddle-wheels. In these the steam-cylinder lies in an inclined
+position, and its connecting-rod directly connects the crank with the
+cross-head. The condenser and air-pump usually lie beneath the
+cross-head guides, and are worked by a bell-crank driven by links on
+each side the connecting-rod, attached to the cross-head. Such engines
+are used to some extent in Europe, and they have been adopted in the
+United States navy for side-wheel gunboats. They are also used on the
+ferry-boats plying between New York and Brooklyn.
+
+[Illustration: FIG. 132.--The Two Rhode Islands, 1836-1876.]
+
+Among the finest illustrations of recent practice in the construction
+of side-wheel steamers are those built for the several routes between
+New York and the cities of New England which traverse Long Island
+Sound. Our illustration exhibits the form of these vessels, and also
+shows well the modifications in structure and size which have been
+made during this generation. The later vessel is 325 feet long, 45
+feet beam, 80 feet wide over the "guards," and 16 feet deep, drawing
+10 feet of water. The "frames" upon which the planking of the hull is
+fastened are of white-oak, and the lighter and "top" timbers of cedar
+and locust. The engine has a steam-cylinder 90 inches in diameter and
+12 feet stroke of piston.[95] On each side the great saloons which
+extend from end to end of the upper deck are state-rooms, containing
+each two berths and elegantly furnished. The engine of this vessel is
+capable of developing about 2,500 horse-power. The great wheels, of
+which the paddle-boxes are seen rising nearly to the height of the
+hurricane-deck, are 37-1/2 feet in diameter and 12 in breadth. The
+hull of this vessel, including all wood-work, weighs over 1,200 tons.
+The weight of the machinery is about 625 tons. The steamer makes 16
+knots an hour when the engine is at its best speed--about 17
+revolutions per minute--and its average speed is about 14 knots on
+its route of 160 miles. The coal required to supply the furnaces of
+such a vessel and with such machinery would be about 3 tons per hour.
+or a little over 2-1/2 pounds per horse-power. The construction of
+such a vessel occupies, usually, about a year, and costs a quarter of
+a million dollars.
+
+  [95] The steam-cylinders of the engines of steamers Bristol and
+  Providence are 110 inches in diameter and of 12 feet stroke.
+
+[Illustration: FIG. 133.--A Mississippi Steamboat.]
+
+The non-condensing direct-acting engine is used principally on the
+Western rivers, driven by steam of from 100 to 150 pounds pressure,
+and exhausts its steam into the atmosphere. It is the simplest
+possible form of direct-acting engine. The valves are usually of the
+"poppet" variety, and are operated by cams which act at the ends of
+long levers having their fulcra on the opposite side of the valve, the
+stem of which latter is attached at an intermediate point. The engine
+is horizontal, and the connecting-rod directly attached to cross-head
+and crank-pin without intermediate mechanism. The paddle-wheel is
+used, sometimes as a stern-wheel, as in the plan of Jonathan Hulls of
+one and a half century ago, sometimes as a side-wheel, as is most
+usual elsewhere. One of the most noted of these steamers, plying on
+the Mississippi, is shown in the preceding sketch.
+
+One of the largest of these steamers was the Grand Republic,[96] a
+vessel 340 feet long, 56 feet beam, and 10-1/4 feet depth. The draught
+of water of this great craft was 3-1/2 feet forward and 4-1/2 aft. The
+two sets of compound engines, 28 and 56 inches diameter and of 10 feet
+stroke, drive wheels 38-1/2 feet in diameter and 18 feet wide. The
+boilers were steel. A steamer built still later on the Ohio has the
+following dimensions: Length, 225 feet; breadth, 35-1/2 feet; depth, 5
+feet; cylinders, 17-3/8 inches in diameter, 6 feet stroke; three
+boilers. The hull and cabin were built at Jeffersonville, Ind. She has
+40 large state-rooms. The cost of the steamer was $40,000.
+
+  [96] Burned in 1877.
+
+These vessels have now opened to commerce the whole extent of the
+great Mississippi basin, transporting a large share of the products of
+a section of country measuring a million and a half square miles--an
+area equal to many times that of New York State, and twelve times that
+of the island of Great Britain--an area exceeding that of the whole of
+Europe, exclusive of Russia and Turkey, and capable, if as thoroughly
+cultivated as the Netherlands, of supporting a population of between
+three and four hundred millions of people.
+
+The steam-engine and propelling apparatus of the modern ocean-steamer
+have now become almost exclusively the compound or double-cylinder
+engine, driving the screw. The form and the location of the machinery
+in the vessel vary with the size and character of the ship which it
+drives. Very small boats are fitted with machinery of quite a
+different kind from that built for large steamers, and war-vessels
+have usually been supplied with engines of a design radically
+different from that adopted for merchant-steamers.
+
+[Illustration: FIG. 134.--Steam-Launch, New York Steam-Power Company.]
+
+The introduction of _Steam-Launches_ and small pleasure-boats driven
+by steam-power is of comparatively recent date, but their use is
+rapidly increasing. Those first built were heavy, slow, and
+complicated; but, profiting by experience, light and graceful boats
+are now built, of remarkable swiftness, and having such improved and
+simplified machinery that they require little fuel and can be easily
+managed. Such boats have strong, carefully-modeled hulls, light and
+strong boilers, capable of making a large amount of dry steam with
+little fuel, and a light, quick-running engine, working without shake
+or jar, and using steam economically.
+
+[Illustration: FIG. 135.--Launch-Engine.]
+
+The above sketch represents the engine built by a New York firm for
+such little craft. This is the smallest size made for the market. It
+has a steam-cylinder 3 inches in diameter and a stroke of piston of 5
+inches, driving a screw 26 inches in diameter and of 3 feet pitch. The
+maximum power of the engine is four or five times the nominal power.
+The boiler is of the form shown in the illustrations of semi-portable
+engines, and has a heating-surface, in this case, of 75 square feet.
+The boat itself is like that seen on page 386, and is 25 feet long, of
+5 feet 8 inches beam, and draws 2-1/4 feet of water. These little
+machines weigh about 150 pounds per nominal horse-power, and the
+boilers about 300.
+
+Some of these little vessels have attained wonderful speed. A British
+steam-yacht, the Miranda, 45-1/2 feet in length, 5-3/4 feet wide, and
+drawing 2-1/2 feet of water, with a total weight of 3-3/4 tons, has
+steamed nearly 18-1/2 miles an hour for short runs. The boat was
+driven by an engine of 6 inches diameter of cylinder and 8 inches
+stroke of piston, making 600 revolutions per minute, driving a
+two-bladed screw 2-1/2 feet in diameter and of 3-1/3 feet pitch. Its
+machinery had a total weight of two tons. Another English yacht, the
+Firefly, is said to have made 18.94 miles an hour. A little French
+yacht, the Hirondelle, has attained a speed of 16 knots, equal to
+about 18-1/2 miles, an hour. This was, however, a much larger vessel
+than the preceding. One of the most remarkable of these little
+steamers is a torpedo-boat built for the United States navy. This
+vessel is 60 feet long, 6 feet wide, and 5 feet deep; its screw is 38
+inches in diameter and of 5 feet pitch, two-bladed, and is driven, by
+a very light engine and boiler, 400 revolutions per minute, the boat
+attaining a speed of 19 to 20 miles an hour. Another little vessel,
+the Vision, made nearly as great speed, developing 20 horse-power with
+engine and boiler weighing but about 400 pounds.
+
+Yachts of high speed require such weight and bulk of engine that but
+little space is left for cabins, and they are usually exceedingly
+uncomfortable vessels. In the Miranda the weight of machinery is more
+than one-half the total weight of the whole. An illustration of the
+more comfortable and more generally liked pleasure-yacht is the Day
+Dream. The length is 105 feet, and the boat draws 5-1/2 feet of
+water. There are two engines, having steam-cylinders 14 inches in
+diameter and of the same length of stroke, direct-acting, condensing,
+and driving a screw, of 7 feet diameter and of 10-1/2 feet pitch, 135
+revolutions a minute, giving the yacht a speed of 13-1/2 knots an
+hour.
+
+[Illustration: FIG. 136.--Horizontal, Direct-acting Naval
+Screw-Engine.]
+
+In larger vessels, as in yachts, in nearly all cases, the ordinary
+screw-engine is direct-acting. Two engines are placed side by side,
+with cranks on the shaft at an angle of 90 deg. with each other. In
+merchant-steamers the steam-cylinders are usually vertical and
+directly over the crank-pins, to which the cross-heads are coupled.
+The condenser is placed behind the engine-frame, or, where a
+jet-condenser is used, the frame itself is sometimes made hollow, and
+serves as a condenser. The air-pump is worked by a beam connected by
+links with the cross-head. The general arrangement is like that shown
+in Figs. 137 and 138. For naval purposes such a form is objectionable,
+since its height is so great that it would be exposed to injury by
+shot. In naval engineering the cylinder is placed horizontally, as in
+Fig. 136, which is a sectional view, representing an horizontal,
+direct-acting naval screw-engine, with jet-condenser and double-acting
+air and circulating pumps. _A_ is the steam-cylinder, _B_ the piston,
+which is connected to the crank-pin by the piston-rod, _D_, and
+connecting-rod, _E_. _F_ is the cross-head guide. The eccentrics,
+_G_, operate the valve, which is of the "three-ported variety," by a
+Stephenson link. Reversing is effected by the hand-wheel, _C_, which,
+by means of a gear, _m_, and a rack, _k_, elevates and depresses the
+link, and thus reverses the valve.
+
+[Illustration: FIG. 137.--Compound Marine Engine. Side Elevation.]
+
+The trunk-engine, in which the connecting-rod is attached directly to
+the piston and vibrates within a trunk or cylinder secured to the
+piston, moving with it, and extending outside the cylinder, like an
+immense hollow piston-rod, is frequently used in the British navy. It
+has rarely been adopted in the United States.
+
+[Illustration: FIG. 138.--Compound Marine Engine. Front Elevation and
+Section.]
+
+In nearly all steam-vessels which have been built for the merchant
+service recently, and in some naval vessels, the compound engine has
+been adopted. Figs. 137 and 138 represent the usual form of this
+engine. Here _A A_, _B B_ are the small and the large, or the
+high-pressure and the low-pressure cylinders respectively. _C C_ are
+the valve-chests. _G G_ is the condenser, which is invariably a
+surface-condenser. The condensing water is sometimes directed around
+the tubes contained within the casing, _G G_, while the steam is
+exhausted around them and among them, and sometimes the steam is
+condensed within the tubes, while the injection-water which is sent
+into the condenser to produce condensation passes around the exterior
+of the tubes. In either case, the tubes are usually of small diameter,
+varying from five-eighths to half an inch, and in length from four to
+seven feet. The extent of heating-surface is usually from one-half to
+three-fourths that of the heating-surface of the boilers.
+
+The air and circulating pumps are placed on the lower part of the
+condenser-casting, and are operated by a crank on the main shaft at
+_N_; or they are sometimes placed as in the style of engine last
+described, and driven by a beam worked by the cross-head. The
+piston-rods, _T S_, are guided by the cross-heads, _V V_, working in
+slipper-guides, and to these cross-heads are attached the
+connecting-rods, _X X_, driving the cranks, _M M_. The cranks are now
+usually set at right angles; in some engines this angle is increased
+to 120 deg., or even 180 deg.. Where it is arranged as here shown, an
+intermediate reservoir, _P O_, is placed between the two cylinders to
+prevent the excessive variations of pressure that would otherwise
+accompany the varying relative motions of the pistons, as the steam
+passes from the high-pressure to the low-pressure cylinder. Steam from
+the boilers enters the high-pressure steam-chest, _X_, and is admitted
+by the steam-valve alternately above and below the piston as usual.
+The exhaust steam is conducted through the exhaust passage around into
+the reservoir, _P_, whence it it is taken by the low-pressure
+cylinder, precisely as the smaller cylinder drew its steam from the
+boiler. From the large or low-pressure cylinder the steam is exhausted
+into the condenser. The valve-gear is usually a Stephenson link, _g
+e_, the position of which is determined, and the reversal of which is
+accomplished, by a hand-wheel, _o_, and screw, _m n p_, which, by the
+bell-crank, _k i_, are attached to the link, _g e_. The "box-framing"
+forms also the hot-well. The surface-condenser is cleared by a
+single-acting air-pump, inside the frame, at _T_. The feed-pump and
+the bilge-pumps are driven from the cross-head of the air-pump.
+
+[Illustration: John Elder.]
+
+The successful introduction of the double-cylinder engine was finally
+accomplished by the exertions of a few engineers, who were at once
+intelligent enough to understand its advantages, and energetic and
+enterprising enough to push it forward in spite of active opposition,
+and powerful enough, pecuniarily and in influence, to succeed. The
+most active and earnest of these eminent men was John Elder, of the
+firm of Randolph, Elder & Co., subsequently John Elder & Co., of
+Glasgow.[97]
+
+  [97] _Vide_ "Memoir of John Elder," W. J. M. Rankine, Glasgow, 1871.
+
+Elder was of Scotch descent. His ancestors had, for generations,
+shown great skill and talent in construction, and had always been
+known as successful millwrights. John Elder was born at Glasgow, March
+8, 1824, and died in London, September 17, 1869. He was educated at
+the Glasgow High-School and in the College of Engineering at the
+University of Glasgow, where, however, his attendance was but for a
+short time. He learned the trade under his father in the workshops of
+the Messrs. Napier, and became an unusually expert draughtsman. After
+spending three years in charge of the drawing-office at the
+engine-building works of Robert Napier, where his father had been
+manager, Elder became a partner in the firm which had previously been
+known as Randolph, Elliott & Co., in the year 1852. The firm commenced
+building iron vessels in 1860.
+
+In the mean time, the experiments of Hornblower and Wolff, of Allaire
+and Smith, and of McNaught, Craddock, and Nicholson, together with the
+theoretical investigations of Thompson, Rankine, Clausius, and others,
+had shown plainly in what direction to look for improvement upon then
+standard engines, and what direction practice was taking with all
+types. The practical deductions which were becoming evident were
+recognized very early by Elder, and he promptly began to put in
+practice the principles which his knowledge of thermo-dynamics and of
+mechanics enabled him to appreciate. He adopted the compound engine,
+and coupled his cranks at angles of 180 deg., in order to avoid losses due
+to the friction of the crank-shaft in its bearings, by effecting a
+partial counterbalancing of pressures on the journals. Elder was one
+of the first to point out the fact that the compound engine had proved
+itself more efficient than the single-cylinder engine, only when the
+pressure of steam carried and the extent to which expansion was
+adopted exceeded the customary practice of his time. His own practice
+was, from the first, successful, and from 1853 to 1867 he and his
+partners were continually engaged in the construction of steamers and
+fitting them with compound engines.
+
+The engines of their first vessel, the Brandon, required but 3-1/4
+pounds of coal per hour and per horse-power, in 1854, when the usual
+consumption was a third more. Five years later, they had built engines
+which consumed a third less than those of the Brandon; and
+thenceforward, for many years, their engines, when of large size,
+exhibited what was then thought remarkable economy, running on a
+consumption of from 2-1/4 to 2-1/2 pounds.
+
+In the year 1865 the British Government ordered a competitive trial of
+three naval vessels, which only differed in the form of their engines.
+The Arethusa was fitted with trunk-engines of the ordinary kind; the
+Octavia had three steam-cylinders, coupled to three cranks placed at
+angles of 120 deg. with each other; and the Constance was fitted with
+compound engines, two sets of three cylinders each, and each taking
+steam from the boiler into one cylinder, passing it through the other
+two with continuous expansion, and finally exhausting from the third
+into the condenser. These vessels, during one week's steaming at sea,
+averaged, respectively, 3.64, 3.17, and 2.51 pounds of coal per hour
+and per horse-power, and the Constance showed a marked superiority in
+the efficiency of the mechanism of her engines, when the losses by
+friction were compared.
+
+The change from the side-lever single-cylinder engine, with
+jet-condenser and paddle-wheels, to the direct-acting compound engine,
+with surface-condenser and screw-propellers, has occurred within the
+memory and under the observation of even young engineers, and it may
+be considered that the revolution has not been completely effected.
+This change in the design of engine is not as great as it at first
+seemed likely to become. Builders have but slowly learned the
+principles stated above in reference to expansion in one or more
+cylinders, and the earlier engines were made with a high and low
+pressure cylinder working on the same connecting-rod, and each machine
+consisted of four steam-cylinders. It was at last discovered that a
+high-pressure single-cylinder engine exhausting into a separate
+larger low-pressure engine might give good results, and the compound
+engine became as simple as the type of engine which it displaced. This
+independence of high and low pressure engines is not in itself novel,
+for the plan of using the exhaust of a high-pressure engine to drive a
+low-pressure condensing engine was one of the earliest of known
+combinations.
+
+The advantage of introducing double engines at sea is considerably
+greater than on land. The coal carried by a steam-vessel is not only
+an item of great importance in consequence of its first cost, but,
+displacing its weight or bulk of freight which might otherwise be
+carried, it represents so much non-paying cargo, and is to be charged
+with the full cost of transportation in addition to first cost. The
+best of steam-coal is therefore usually chosen for steamers making
+long voyages, and the necessity of obtaining the most economical
+engines is at once seen, and is fully appreciated by steamship
+proprietors. Again, an economy of one-fourth of a pound per
+horse-power per hour gives, on a large transatlantic steamer, a saving
+of about 100 tons of coal for a single voyage. To this saving of cost
+is to be added the gain in wages and sustenance of the labor required
+to handle that coal, and the gain by 100 tons of freight carried in
+place of the coal.
+
+For many years the change which has here been outlined, in the forms
+of engine and the working of steam expansively, was retarded by the
+inefficiency of methods and tools used in construction. With gradual
+improvement in tools and in methods of doing work, it became possible
+to control higher steam and to work it successfully; and the change in
+this direction has been steadily going on up to the present time with
+all types of steam-engine. At sea this rise of pressure was for a
+considerable time retarded by the serious difficulty encountered in
+the tendency of the sulphate of lime to deposit in the boiler. When
+steam-pressure had risen to 25 pounds per square inch, it was found
+that no amount of "blowing out" would prevent the deposition of
+seriously large quantities of this salt, while at the lower pressures
+at first carried at sea no troublesome precipitation occurred, and the
+only precaution necessary was to blow out sufficient brine to prevent
+the precipitation of common salt from a supersaturated solution. The
+introduction of surface-condensation was promptly attempted as the
+remedy for this evil, but for many years it was extremely doubtful
+whether its disadvantages were not greater than its advantages. It was
+found very difficult to keep the condensers tight, and boilers were
+injured by some singular process of corrosion, evidently due to the
+presence of the surface-condenser. The simple expedient of permitting
+a very thin scale to form in the boiler was, after a time, hit upon as
+a means of overcoming this difficulty, and thenceforward the greatest
+obstacle to the general introduction was the conservative disposition
+found among those who had charge of marine machinery, which
+conservatism regarded with suspicion every innovation. Another trouble
+arose from the difficulty of finding men neither too indolent nor too
+ignorant to take charge of the new condenser, which, more complicated
+and more readily disarranged than the old, demanded a higher class of
+attendants. Once introduced, however, the surface-condenser removed
+the obstacle to further elevation of steam-pressure, and the rise from
+20 to 60 pounds pressure soon occurred. Elder and his competitors on
+the Clyde were the first to take advantage of the fact when these
+higher pressures became practicable.
+
+The lightness of engine and the smaller weight of boiler secured when
+the simpler type of "compound" engine is used are great advantages,
+and, when coupled with the fact that by no other satisfactory device
+can great expansion and consequent economy of fuel be obtained at sea,
+the advantages are such as to make the adoption of this style of
+engine imperative for ship-propulsion.
+
+This extreme lightness in machinery has been largely, also, the result
+of very careful and skillful designing, of intelligent construction,
+and of care in the selection and use of material. British builders
+had, until after the introduction of these later types of
+vessels-of-war, been distinguished rather by the weight of their
+machinery than for nice calculation and proportioning of parts. Now
+the engines of the heavy iron-clads are models of good proportions,
+excellence in materials, and of workmanship, which are well worthy of
+study. The weight per indicated horse-power has been reduced from 400
+or 500 pounds to less than half that amount within the last ten years.
+This has been accomplished by forcing the boilers--although thus, to
+some extent, losing economy--by higher steam-pressure, a very much
+higher piston-speed, reduction of friction of parts, reduction of
+capacity for coal-stowage, and exceedingly careful proportioning.
+The reduction of coal-bunker capacity is largely compensated by
+the increase of economy secured by superheating, by increased
+expansion, elevation of piston-speed, and the introduction of
+surface-condensation.
+
+A good marine steam-engine of the form which was considered standard
+15 or 20 years ago, having low-pressure boilers carrying steam at 20
+or 25 pounds pressure as a maximum, expanding twice or three times,
+and having a jet-condenser, would require about 30 or 35 pounds of
+feed-water per horse-power per hour; substituting surface-condensation
+for that produced by the jet brought down the weight of steam used to
+from 25 to 30 pounds; increasing steam-pressure to 60 pounds,
+expanding from five to eight times, and combining the special
+advantages of the superheater and the compound engine with
+surface-condensation, has reduced the consumption of steam to 20, or
+even, in some cases, 15 pounds of steam per horse-power per hour.
+Messrs. Perkins, of London, guarantee, as has already been stated, to
+furnish engines capable of giving a horse-power with a consumption of
+but 1-1/4 pound of coal. Mr. C. E. Emery reports the United States
+revenue-steamer Hassler, designed by him, to have given an ordinary
+sea-going performance which is probably fully equal to anything yet
+accomplished. The Hassler is a small steamer, of but 151 feet in
+length, 24-1/2 feet beam, and 10 feet draught. The engines have
+steam-cylinders 18.1 and 28 inches diameter, respectively, and of 28
+inches stroke of piston, indicating 125 horse-power; with steam at 75
+pounds pressure, and at a speed of but 7 knots, the coal consumed was
+but 1.87 pound per horse-power per hour.
+
+The committee of the British Admiralty on designs of ships-of-war have
+reported recently: "The carrying-power of ships may certainly be to
+some extent increased by the adoption of compound engines in her
+Majesty's service. Its use has recently become very general in the
+mercantile marine, and the weight of evidence in favor of the large
+economy of fuel thereby gained is, to our minds, overwhelming and
+conclusive. We therefore beg earnestly to recommend that the use of
+compound engines may be generally adopted in ships-of-war hereafter to
+be constructed, and applied, whenever it can be done with due regard
+to economy and to the convenience of the service, to those already
+built."
+
+The forms of screws now employed are exceedingly diverse, but those in
+common use are not numerous. In naval vessels it is common to apply
+screws of two blades, that they may be hoisted above water into a
+"well" when the vessel is under sail, or set with the two blades
+directly behind the stern-post, when their resistance to the forward
+motion of the vessel will be comparatively small. In other vessels,
+and in the greater number of full-power naval vessels, screws of three
+or four blades are used.
+
+The usual form of screw (Fig. 139) has blades of nearly equal breadth
+from the hub to the periphery, or slightly widening toward their
+extremities, as is seen in an exaggerated degree in Fig. 140,
+representing the form adopted for tug-boats, where large surface near
+the extremity is more generally used than in vessels of high speed
+running free. In the Griffith screw, which has been much used, the hub
+is globular and very large. The blades are secured to the hub by
+flanges, and are bolted on in such a manner that their position may be
+changed slightly if desired. The blades are shaped like the section of
+a pear, the wider part being nearest the hub, and the blades tapering
+rapidly toward their extremities. A usual form is intermediate between
+the last, and is like that shown in Fig. 141, the hub being
+sufficiently enlarged to permit the blades to be attached as in the
+Griffith screw, but more nearly cylindrical, and the blades having
+nearly uniform width from end to end.
+
+[Illustration: FIG. 139.--Screw-Propeller.]
+
+[Illustration: FIG. 140.--Tug-boat Screw.]
+
+[Illustration: FIG. 141.--Hirsch Screw.]
+
+The pitch of a screw is the distance which would be traversed by the
+screw in one revolution were it to move through the water without
+slip; i. e., it is double the distance _C D_, Fig. 140. _C D'_
+represents the helical path of the extremity of the blade _B_, and _O
+E F H K_ is that of the blade _A_. The proportion of diameter to the
+pitch of the screw is determined by the speed of the vessel. For low
+speed the pitch may be as small as 1-1/4 the diameter. For vessels of
+high speed the pitch is frequently double the diameter. The diameter
+of the screw is made as great as possible, since the slip decreases
+with the increase of the area of screw-disk. Its length is usually
+about one-sixth of the diameter. A greater length produces loss by
+increase of surface causing too great friction, while a shorter screw
+does not fully utilize the resisting power of the cylinder of water
+within which it works, and increased slip causes waste of power. An
+empirical value for the probable slip in vessels of good shape, which
+is closely approximate usually, is _S_ = 4(_M_/_A_), in which _S_ is
+the slip per cent., and _M_ and _A_ are the areas of the midship
+section and of the screw-disk in square feet.
+
+The most effective screws have slightly greater pitch at the periphery
+than at the hub, and an increasing pitch from the forward to the rear
+part of the screw. The latter method of increasing pitch is more
+generally adopted alone. The thrust of the screw is the pressure which
+it exerts in driving the vessel forward. In well-formed vessels, with
+good screws, about two-thirds of the power applied to the screw is
+utilized in propulsion, the remainder being wasted in slip and other
+useless work. Its efficiency is in such a case, therefore, 66 per
+cent. Twin screws, one on each side of the stern-post, are sometimes
+used in vessels of light draught and considerable breadth, whereby
+decreased slip is secured.
+
+As has already been stated, the introduction of the compound engine
+has been attempted, but with less success than in Europe, by several
+American engineers.
+
+The most radical change in the methods of ship-propulsion which has
+been successfully introduced in some localities has been the adoption
+of a system of "wire-rope towage." It is only well adapted for cases
+in which the steamer traverses the same line constantly, moving
+backward and forward between certain points, and is never compelled to
+deviate to any considerable extent from the path selected. A similar
+system is in use in Canada, but it has not yet come into use in the
+United States, notwithstanding the fact that, wherever its adoption is
+practicable, it has a marked superiority in economy over the usual
+methods of propulsion. With chain or rope traction there is no loss by
+slip or oblique action, as in both screw and paddle-wheel propulsion.
+In the latter methods these losses amount to an important fraction of
+the total power; they rarely, if ever, fall below a total of 25 per
+cent., and probably in towage exceed 50 per cent. The objection to the
+adoption of chain-propulsion, as it is also often called, is the
+necessity of following closely the line along which the chain or the
+rope is laid. There is, however, much less difficulty than would be
+anticipated in following a sinuous route or in avoiding obstacles in
+the channel or passing other vessels. The system is particularly well
+adapted for use on canals.
+
+The steam-boilers in use in the later and best marine engineering
+practice are of various forms, but the standard types are few in
+number. That used on river-steamers in the United States has already
+been described.
+
+[Illustration: FIG. 142.--Marine Fire-tubular Boiler. Section.]
+
+Fig. 142 is a type of marine tubular boiler which is in most extensive
+use in sea-going steamers for moderate pressure, and particularly for
+naval vessels. Here the gases pass directly into the back connection
+from the fire, and thence forward again, through horizontal tubes, to
+the front connection and up the chimney. In naval vessels the
+steam-chimney is omitted, as it is there necessary to keep all parts
+of the boiler as far below the water-line as possible. Steam is taken
+from the boiler by pipes which are carried from end to end of the
+steam-space, near the top of the boiler, the steam entering these
+pipes through small holes drilled on the other side. Steam is thus
+taken from the boiler "wet," but no large quantity of water can
+usually be "entrained" by the steam.
+
+A marine boiler has been quite extensively introduced into the United
+States navy, in which the gases are led from the back connection
+through a tube-box around and among a set of upright water-tubes,
+which are filled with water, circulation taking place freely from the
+water-space immediately above the crown-sheet of the furnace up
+through these tubes into the water-space above them. These
+"water-tubular" boilers have a slight advantage over the
+"fire-tubular" boilers already described in compactness, in steaming
+capacity, and in economical efficiency. They have a very marked
+advantage in the facility with which the tubes may be scraped or freed
+from the deposit when a scale of sulphate of lime or other salt has
+formed within them by precipitation from the water. The fire-tubular
+boiler excels in convenience of access for plugging up leaking tubes,
+and is much less costly than the water-tubular. The water-tube class
+of boilers still remain in extensive use in the United States naval
+steamers. They have never been much used in the merchant service,
+although introduced by James Montgomery in the United States and by
+Lord Dundonald in Great Britain twenty years earlier. Opinion still
+remains divided among engineers in regard to their relative value.
+They are gradually reassuming prominence by their introduction in the
+modified form of sectional boilers.
+
+[Illustration: FIG. 143.--Marine High-Pressure Boiler. Section.]
+
+Marine boilers are now usually given the form shown in section in Fig.
+143. This form of boiler is adopted where steam-pressures of 60
+pounds and upward are carried, as in steam-vessels supplied with
+compound engines, cylindrical forms being considered the best with
+high pressures. The large cylindrical flues, therefore, form the
+furnaces as shown in the transverse sectional view. The gases rise, as
+shown in the longitudinal section, through the connection, and pass
+back to the end of the boiler through the tubes, and thence, instead
+of entering a steam-chimney, they are conducted by a smoke-connection,
+not shown in the sketch, to the smoke funnel or stack. In
+merchant-steamers, a steam-drum is often mounted horizontally above
+the boiler. In other cases a separator is attached to the steam-pipe
+between boilers and engines. This usually consists of an iron tank,
+divided by a vertical partition extending from the top nearly to the
+bottom. The steam, entering the top at one side of this partition,
+passes underneath it, and up to the top on the opposite side, where it
+issues into a steam-pipe leading directly to the engine. The sudden
+reversal of its course at the bottom causes it to leave the suspended
+water in the bottom of the separator, whence it is drained off by
+pipes.
+
+The most interesting illustrations of recent practice in marine
+engineering and naval architecture are found in the steamers which are
+now seen on transoceanic routes for the merchant service, and, in the
+naval service, in the enormous iron-clads which have been built in
+Great Britain.
+
+The City of Peking is one of the finest examples of American practice.
+This vessel was constructed for the Pacific Mail Company. The hull is
+423 feet long, of 48 feet beam, and 38-1/2 feet deep. Accommodations
+are furnished for 150 cabin and 1,800 steerage passengers, and the
+coal-bunkers "stow" 1,500 tons of coal. The iron plates of which the
+sides and bottom are made are from 11/16 to one inch in thickness. The
+weight of iron used in construction was about 5,500,000 pounds. The
+machinery weighed nearly 2,000,000 pounds, with spare gear and
+accessory apparatus. The engines are compound, with two
+steam-cylinders of 51 inches and two of 88 inches diameter, and a
+stroke of piston of 4-1/2 feet. The condensing water is sent through
+the surface-condensers by circulating-pumps driven by their own
+engines. Ten boilers furnish steam to these engines, each having a
+diameter of 13 feet, a length of 13-1/2 feet, and a thickness of
+"shell" of 13/16 inch. Each has three furnaces, and contains 204
+tubes of an outside diameter of 3-1/4 inches. All together, they
+have 520 square feet of grate-surface and 17,000 square feet of
+heating-surface. The area of cooling-surface in the condensers is
+10,000 square feet. The City of Rome, a ship of later design, is 590
+feet long, "over all," 52 feet beam, 52 feet deep, and measures 8,300
+tons. The engines, of 8,500 horse-power, will drive the vessel 18
+knots (21 miles) an hour; they have six steam-cylinders (three high
+and three low pressure), and are supplied with steam by 8 boilers
+heated by 48 furnaces. The hull is of steel, the bottom double, and
+the whole divided into ten compartments by transverse bulkheads. Two
+longitudinal bulkheads in the engine and boiler compartments add
+greatly to the safety of the vessel.
+
+The most successful steam-vessels in general use are these
+screw-steamers of transoceanic lines. Those of the transatlantic lines
+are now built from 350 to 550 feet long, generally propelled from 12
+to 18 knots (14 to 21 miles) an hour, by engines of from 3,000 to
+8,000 horse-power, consuming from 70 to 250 tons of coal a day, and
+crossing the Atlantic in from eight to ten days. These vessels are now
+invariably fitted with the compound engine and surface-condensers. One
+of these vessels, the Germanic, has been reported at Sandy Hook, the
+entrance to New York Harbor, in 7 days 11 hours 37 minutes from
+Queenstown--a distance, as measured by the log and by observation, of
+2,830 miles. Another steamer, the Britannic, has crossed the Atlantic
+in 7 days 10 hours and 53 minutes. These vessels are of 5,000 tons
+burden, of 750 "nominal" horse-power (probably 5,000 actual).
+
+[Illustration: FIG. 144.--The Modern Steamship.]
+
+The modern steamship is as wonderful an illustration of ingenuity and
+skill in all interior arrangements as in size, power, and speed. The
+size of sea-going steamers has become so great that it is unsafe to
+intrust the raising of the anchor or the steering of the vessel to
+manual power and skill; and these operations, as well as the loading
+and unloading of the vessel, are now the work of the same great
+motor--steam.
+
+The now common form of auxiliary engine for controlling the helm is
+one of the inventions of the American engineer F. E. Sickels, who
+devised the "Sickels cut-off," and was first invented about 1850. It
+was exhibited at London at the International Exhibition of 1851. It
+consists[98] principally of two cylinders working at right angles upon
+a shaft geared into a large wheel fastened by a friction-plate lined
+with wood, and set by a screw to any desired pressure on the
+steering-apparatus. The wheel turned by the steersman is connected
+with the valve-gear of the cylinders, so that the steam, or other
+motor, will move the rudder precisely as the helmsman moves the wheel
+adjusting the steam-valves. This wheel thus becomes the
+steering-wheel. The apparatus is usually so arranged that it may be
+connected or disconnected in an instant, and hand-steering adopted if
+the smoothness of the sea and the low speed of the vessel make it
+desirable or convenient. This method was first adopted in the United
+States on the steamship Augusta.
+
+  [98] "Official Catalogue," 1862, vol. iv., Class viii., p. 123.
+
+The same inventor and others have contrived "steam-windlasses," some
+of which are in general use on large vessels. The machinery of these
+vessels is also often fitted with a steam "reversing-gear," by means
+of which the engines are as easily man[oe]uvred as are those of the
+smallest vessels, to which hand-gear is always fitted. In one of these
+little auxiliary engines, as devised by the author, a small handle
+being adjusted to a marked position, as to the point marked "stop" on
+an index-plate, the auxiliary engine at once starts, throws the
+valve-gear into the proper position--as, if a link-motion, into
+"middle-gear"--thus stopping the large engines, and then it itself
+stops. Setting the handle so that its pointer shall point to "ahead,"
+the little engine starts again, sets the link in position to go ahead,
+thus starting the large engines, and again stops itself. If set at
+"back," the same series of operations occurs, leaving the main engines
+backing and the little "reversing engine" stopped. A number of forms
+of reversing engine are in use, each adapted to some one type of
+engine.
+
+The hull of the transatlantic steamer is now always of iron, and is
+divided into a number of "compartments," each of which is water-tight
+and separated from the adjacent compartments by iron "bulkheads," in
+which are fitted doors which, when closed, are also water-tight. In
+some cases these doors close automatically when the water rises in the
+vessel, thus confining it to the leaking portion.
+
+Thus we have already seen a change in transoceanic lines from steamers
+like the Great Western (1837), 212 feet in length, of 35-1/2 feet
+beam, and 23 feet depth, driven by engines of 450 horse-power, and
+requiring 15 days to cross the Atlantic, to steamships over 550 feet
+long, 55 feet beam, and 55 feet deep, with engines of 10,000
+horse-power, crossing the Atlantic in 7 days; iron substituted for
+wood in construction, the cost of fuel reduced one-half, and the speed
+raised from 8 to 18 knots and over. In the earlier days of steamships
+they were given a proportion of length to breadth of from 5 to 6 to 1;
+in forty years the proportion increased until 11 to 1 was reached.
+
+The whole naval establishment of every country has been greatly
+modified by the recent changes in methods of attack and defense; but
+the several classes of ships which still form the naval marine are all
+as dependent upon their steam-machinery as ever.
+
+[Illustration: H. B. M. Iron-Clad Captain. H. B. M. Iron-Clad
+Thunderer. U. S. Iron-Clad Dictator. U. S. Iron-Clad Monitor. H. B. M.
+Iron-Clad Giatton. French Iron-Clad Dunderberg. FIG. 145.--Modern
+Iron-Clads.]
+
+It is only recently that the attempt seems to have been made to
+determine a classification of war-vessels and to plan a naval
+establishment which shall be likely to meet fully the requirements of
+the immediate future. It has hitherto been customary simply to make
+each ship a little stronger, faster, or more powerful to resist or to
+make attack than was the last. The fact that the direction of
+progress in naval science and architecture is plainly perceivable, and
+that upon its study may be based a fair estimate of the character and
+relative distribution of several classes of vessels, seems to have
+been appreciated by very few.
+
+In the year 1870 the writer proposed[99] a classification of vessels
+other than torpedo-vessels, which has since been also proposed in a
+somewhat modified form by Mr. J. Scott Russell.[100] The author then
+remarked that the increase so rapidly occurring in weight of ordnance
+and of armor, and in speed of war-vessels, would probably soon compel
+a division of the vessels of every navy into three classes of ships,
+exclusive of torpedo-vessels, one for general service in time of
+peace, the others for use only in time of war.
+
+  [99] _Journal Franklin Institute_, 1870. H. B. M. S. Monarch.
+
+  [100] London _Engineering_, 1875.
+
+"The first class may consist of unarmored vessels of moderate size,
+fair speed under steam, armed with a few tolerably heavy guns, and
+carrying full sail-power.
+
+"The second class may be vessels of great speed under steam,
+unarmored, carrying light batteries and as great spread of canvas as
+can readily be given them; very much such vessels as the Wampanoag
+class of our own navy were intended to be--calculated expressly to
+destroy the commerce of an enemy.
+
+"The third class may consist of ships carrying the heaviest possible
+armor and armament, with strongly-built bows, the most powerful
+machinery that can be given them, of large coal-carrying capacity, and
+unencumbered by sails, everything being made secondary to the one
+object of obtaining victory in contending with the most powerful of
+possible opponents. Such vessels could never go to sea singly, but
+would cruise in couples or in squadrons. It seems hardly doubtful that
+attempts to combine the qualities of all classes in a single vessel,
+as has hitherto been done, will be necessarily given up, although the
+classification indicated will certainly tend largely to restrict naval
+operations."
+
+The introduction of the stationary, the floating, and the automatic
+classes of torpedoes, and of torpedo-vessels, has now become
+accomplished, and this element, which it was predicted by Bushnell and
+by Fulton three-quarters of a century ago would at some future time
+become important in warfare, is now well recognized by all nations.
+How far it may modify future naval establishments cannot be yet
+confidently stated, but it seems sufficiently evident that the attack,
+by any navy, of stationary defenses protected by torpedoes is now
+quite a thing of the past. It may be perhaps looked upon as
+exceedingly probable that torpedo-ships of very high speed will yet
+drive all heavily-armored vessels from the ocean, thus completing the
+historic parallel between the man-in-armor of the middle ages and the
+armored man-of-war of our own time.[101]
+
+  [101] _Vide_ "Report on Machinery and Manufactures, etc., at
+  Vienna," by the author, Washington, 1875.
+
+Of these classes, the third is of most interest, as exhibiting most
+perfectly the importance and variety of the work which the
+steam-engine is made to perform. On the later of these vessels, the
+anchor is raised by a steam anchor-hoisting apparatus; the heavier
+spars and sails are handled by the aid of a steam-windlass; the helm
+is controlled by a steering-engine, and the helmsman, with his little
+finger, sets in motion a steam-engine, which adjusts the rudder with a
+power which is unimpeded by wind or sea, and with an exactness that
+could not be exceeded by the hand-steering gear of a yacht; the guns
+are loaded by steam, are elevated or depressed, and are given lateral
+training, by the same power; the turrets in which the guns are incased
+are turned, and the guns are whirled toward every point of the
+compass, in less time than is required to sponge and reload them; and
+the ship itself is driven through the water by the power of ten
+thousand horses, at a speed which is only excelled on land by that of
+the railroad-train.
+
+The British Minotaur was one of the earlier iron-clads. The great
+length and consequent difficulty of man[oe]uvring, the defect of
+speed, and the weakness of armor of these vessels have led to the
+substitution of far more effective designs in later constructions. The
+Minotaur is a four-masted screw iron-clad, 400 feet long, of 59 feet
+beam and 26-1/2 feet draught of water. Her speed at sea is about
+12-1/2 knots, and her engines develop, as a maximum, nearly 6,000
+indicated horse-power. Her heaviest armor-plates are but 6 inches in
+thickness. Her extreme length and her unbalanced rudder make it
+difficult to turn rapidly. With _eighteen men at the steering-wheel_
+and sixty others on the tackle, the ship, on one occasion, was 7-1/2
+minutes in turning completely around. These long iron-clads were
+succeeded by the shorter vessels designed by Mr. E. J. Reed, of which
+the first, the Bellerophon, was of 4,246 tons burden, 300 feet long by
+56 feet beam, and 24-1/2 feet draught, of the 14-knot speed, with
+4,600 horse-power; and having the "balanced rudder" used many years
+earlier in the United States by Robert L. Stevens,[102] it can turn in
+four minutes with eight men at the wheel. The cost of construction was
+some $600,000 less than that of the Minotaur. A still later vessel,
+the Monarch, was constructed on a system quite similar to that known
+in the United States as the Monitor type, or as a turreted iron-clad.
+This vessel is 330 feet long, 57-1/2 feet wide, and 36 feet deep,
+drawing 24-1/2 feet of water. The total weight of ship and contents is
+over 8,000 tons, and the engines are of over 8,500 horse-power. The
+armor is 6 and 7 inches thick on the hull, and 8 inches on the two
+turrets, over a heavy teak backing. The turrets contain each two
+12-inch rifled guns, weighing 25 tons each, and, with a charge of 70
+pounds of powder, throwing a shot of 600 pounds weight with a velocity
+of 1,200 feet per second, and giving it a _vis viva_ equivalent to the
+raising of over 6,100 tons one foot high, and equal to the work of
+penetrating an iron plate 13-1/2 inches thick. This immense vessel is
+driven by a pair of "single-cylinder" engines having steam-cylinders
+_ten feet_ in diameter and of 4-1/2 feet stroke of piston, driving a
+two-bladed Griffith screw of 23-1/2 feet diameter and 26-1/2 feet
+pitch, 65 revolutions, at the maximum speed of 14.9 knots, or about
+17-1/2 miles, an hour. To drive these powerful engines, boilers having
+an aggregate of about 25,000 square feet (or more than a half-acre) of
+heating-surface are required, with 900 square feet of grate-surface.
+The refrigerating surface in the condensers has an area of 16,500
+square feet--over one-third of an acre. The cost of these engines and
+boilers was L66,500.
+
+  [102] Still in use on the Hoboken ferry-boats.
+
+Were all this vast steam-power developed, giving the vessel a speed of
+15 knots, the ship, if used as a "ram," would strike an enemy at rest
+with the tremendous "energy" of 48,000 foot-tons--equal to the shock
+of the projectiles of eight or nine such guns as are carried by the
+iron-clad itself, simultaneously discharged upon one spot.
+
+But even this great vessel is less formidable than later vessels. One
+of the latter, the Inflexible, is a shorter but wider and deeper ship
+than the Monarch, measuring 320 feet long, 75 feet beam, and 25
+draught, displacing over 10,000 tons. The great rifles carried by this
+vessel weigh 81 tons each, throwing shot weighing a half-ton from
+behind iron-plating two feet in thickness. The steam-engines are of
+about the same power as those of the Monarch, and give this enormous
+hull a speed of 14 knots an hour.
+
+The navy of the United States does not to-day possess iron-clads of
+power even approximating that of either of several classes of British
+and other foreign naval vessels.
+
+The largest vessel of any class yet constructed is the Great Eastern
+(Fig. 146), begun in 1854 and completed in 1859, by J. Scott Russell,
+on the Thames, England. This ship is 680 feet long, 83 feet wide, 58
+feet deep, 28 feet draught, and of 24,000 tons measurement. There are
+four paddle and four screw engines, the former having steam-cylinders
+74 inches in diameter, with 14 feet stroke, the latter 84 inches in
+diameter and 4 feet stroke. They are collectively of 10,000 actual
+horse-power. The paddle-wheels are 56 feet in diameter, the screw 24
+feet. The steam-boilers supplying the paddle-engines have 44,000
+square feet (more than an acre) of heating-surface. The boilers
+supplying the screw-engines are still larger. At 30 feet draught, this
+great vessel displaces 27,000 tons. The engines were designed to
+develop 10,000 horse-power, driving the ship at the rate of 16-1/2
+statute miles an hour.
+
+[Illustration: FIG. 146.--The Great Eastern.]
+
+The figures quoted in the descriptions of these great steamships do
+not enable the non-professional reader to form a conception of the
+wonderful power which is concentrated within so small a space as is
+occupied by their steam-machinery. The "horse-power" of the engines is
+that determined by James Watt as the maximum obtainable for eight
+hours a day from the strongest London draught-horses. The ordinary
+average draught-horse would hardly be able to exert two-thirds as much
+during the eight hours' steady work of a working-day. The working-day
+of the steam-engine, on the other hand, is twenty-four hours in
+length.
+
+[Illustration: FIG. 147.--The Great Eastern at Sea.]
+
+The work of the 10,000 horse-power engines of the Great Eastern could
+be barely equaled by the efforts of 15,000 horses; but to continue
+their work uninterruptedly, day in and day out, for weeks together, as
+when done by steam, would require at least three relays, or 45,000
+horses. Such a stud would weigh 25,000 tons, and if harnessed "tandem"
+would extend thirty miles. It is only by such a comparison that the
+mind can begin to comprehend the utter impossibility of accomplishing
+by means of animal power the work now done for the world by steam.
+The cost of the greater power is but about one-tenth that of
+horse-power, and by its means tasks are accomplished with ease which
+are absolutely impossible of accomplishment by animal power.
+
+It is estimated that the total steam-power of the world is about
+15,000,000 horse-power, and that, were horses actually employed to do
+the work which these engines would be capable of doing were they kept
+constantly in operation, the number required would exceed 60,000,000.
+
+Thus, from the small beginnings of the Comte d'Auxiron and the Marquis
+de Jouffroy in France, of Symmington in Great Britain, and of Henry,
+Rumsey, and Fitch, and of Fulton and Stevens, in the United States,
+steam-navigation has grown into a great and inestimable aid and
+blessing to mankind.
+
+We to-day cross the ocean with less risk, and transport ourselves and
+our goods at as little cost in either time or money as, at the
+beginning of the century, our parents experienced in traveling
+one-tenth the distance.
+
+It is largely in consequence of this ingenious application of a power
+that reminds one of the fabled genii of Eastern romance, that the
+mechanic and the laborer of to-day enjoy comforts and luxuries that
+were denied to wealth, and to royalty itself, a century ago.
+
+The magnitude of our modern steamships excites the wonder and
+admiration of even the people of our own time; and there is certainly
+no creation of art that can be grander in appearance than a
+transatlantic steamer a hundred and fifty yards in length, and
+weighing, with her stores, five or six thousand tons, as she starts on
+her voyage, moved by engines equal in power to the united strength of
+thousands of horses; none can more fully awaken a feeling of awe than
+an immense structure like the great modern iron-clads (Fig. 145),
+vessels having a total weight of 8,000 to 10,000 tons, and propelled
+by steam-engines of as many horse-power, carrying guns whose shot
+penetrate solid iron 20 inches thick, and having a power of impact,
+when steaming at moderate speed, sufficient to raise 35,000 tons a
+foot high.
+
+Far more huge than the Monarch among the iron-clads even is that
+prematurely-built monster, the Great Eastern (Fig. 147), already
+described, an eighth of a mile long, and with steam doing the work of
+a stud of 45,000 horses.
+
+Thus we are to-day witnessing the literal fulfillment of the
+predictions of Oliver Evans and of John Stevens, and almost that
+contained in the couplets written by the poet Darwin, who, more than a
+century ago, before even the earliest of Watt's improvements had
+become generally known, sang:
+
+    "Soon shall thy arm, unconquered Steam, afar
+    Drag the slow barge, or drive the rapid car;
+    Or, on wide-waving wings expanded, bear
+    The flying chariot through the fields of air."
+
+[Illustration]
+
+
+
+
+CHAPTER VII.
+
+_THE PHILOSOPHY OF THE STEAM-ENGINE._
+
+THE HISTORY OF ITS GROWTH; ENERGETICS AND THERMO-DYNAMICS.
+
+  "Of all the features which characterize this progressive economical
+  movement of civilized nations, that which first excites attention,
+  through its intimate connection with the phenomena of production, is
+  the perpetual and, so far as human foresight can extend, the
+  unlimited growth of man's power over Nature. Our knowledge of the
+  properties and laws of physical objects shows no sign of approaching
+  its ultimate boundaries; it is advancing more rapidly, and in a
+  greater number of directions at once, than in any previous age or
+  generation, and affording such frequent glimpses of unexplored
+  fields beyond as to justify the belief that our acquaintance with
+  Nature is still almost in its infancy."--MILL.
+
+
+The growth of the philosophy of the steam-engine presents as
+interesting a study as that of the successive changes which have
+occurred in its mechanism.
+
+In the operation of the steam-engine we find illustrated many of the
+most important principles and facts which constitute the physical
+sciences. The steam-engine is an exceedingly ingenious, but,
+unfortunately, still very imperfect, machine for transforming the
+heat-energy obtained by the chemical combination of a combustible with
+the supporter of combustion into mechanical energy. But the original
+source of all this energy is found far back of its first appearance in
+the steam-boiler. It had its origin at the beginning, when all Nature
+came into existence. After the solar system had been formed from the
+nebulous chaos of creation, the glowing mass which is now called the
+sun was the depository of a vast store of heat-energy, which was
+thence radiated into space and showered upon the attendant worlds in
+inconceivable quantity and with unmeasured intensity. During the past
+life of the globe, the heat-energy received from the sun upon the
+earth's surface was partly expended in the production of great
+forests, and the storage, in the trunks, branches, and leaves of the
+trees of which they were composed, of an immense quantity of carbon,
+which had previously existed in the atmosphere, combined with oxygen,
+as carbonic acid. The great geological changes which buried these
+forests under superincumbent strata of rock and earth resulted in the
+formation of coal-beds, and the storage, during many succeeding ages,
+of a vast amount of carbon, of which the affinity for oxygen remained
+unsatisfied until finally uncovered by the hand of man. Thus we owe to
+the heat and light of the sun, as was pointed out by George
+Stephenson, the incalculable store of potential energy upon which the
+human race is so dependent for life and all its necessaries, comforts,
+and luxuries.
+
+This coal, thrown upon the grate in the steam-boiler, takes fire, and,
+uniting again with the oxygen, sets free heat in precisely the same
+quantity that it was received from the sun and appropriated during the
+growth of the tree. The actual energy thus rendered available is
+transferred, by conduction and radiation, to the water in the
+steam-boiler, converts it into steam, and its mechanical effect is
+seen in the expansion of the liquid into vapor against the
+superincumbent pressure. Transferred from the boiler to the engine,
+the steam is there permitted to expand, doing work, and the
+heat-energy with which it is charged becomes partly converted into
+mechanical energy, and is applied to useful work in the mill or to
+driving the locomotive or the steamboat.
+
+Thus we may trace the store of energy received from the sun and
+contained in our coal through its several changes until it is finally
+set at work; and we might go still further and observe how, in each
+case, it is again usually re-transformed and again set free as
+heat-energy.
+
+The transformation which takes place in the furnace is a chemical
+change; the transfer of heat to the water and the subsequent phenomena
+accompanying its passage through the engine are physical changes, some
+of which require for their investigation abstruse mathematical
+operations. A thorough comprehension of the principles governing the
+operation of the steam-engine, therefore, can only be attained after
+studying the phenomena of physical science with sufficient minuteness
+and accuracy to be able to express with precision the laws of which
+those sciences are constituted. The study of the philosophy of the
+steam-engine involves the study of chemistry and physics, and of the
+new science of energetics, of which the now well-grown science of
+thermo-dynamics is a branch. This sketch of the growth of the
+steam-engine may, therefore, be very properly concluded by an outline
+of the growth of the several sciences which together make up its
+philosophy, and especially of the science of thermo-dynamics, which is
+peculiarly the science of the steam-engine and of the other
+heat-engines.
+
+These sciences, like the steam-engine itself, have an origin which
+antedates the commencement of the Christian era; but they grew with an
+almost imperceptible growth for many centuries, and finally, only a
+century ago, started onward suddenly and rapidly, and their progress
+has never since been checked. They are now fully-developed and
+well-established systems of natural philosophy. Yet, like that of the
+steam-engine and of its companion heat-engines, their growth has by no
+means ceased; and, while the student of science cannot do more than
+indicate the direction of their progress, he can readily believe that
+the beginning of the end is not yet reached in their movement toward
+completeness, either in the determination of facts or in the
+codification of their laws.
+
+When Hero lived at Alexandria, the great "Museum" was a most important
+centre, about which gathered the teachers of all then known
+philosophies and of all the then recognized but unformed sciences, as
+well as of all those technical branches of study which had already
+been so far developed as to be capable of being systematically taught.
+Astronomical observations had been made regularly and uninterruptedly
+by the Chaldean astrologers for two thousand years, and records
+extending back many centuries had been secured at Babylon by
+Calisthenes and given to Aristotle, the father of our modern
+scientific method. Ptolemy had found ready to his hand the records of
+Chaldean observers of eclipses extending back nearly 650 years, and
+marvelously accurate.[103]
+
+  [103] Their estimate of the length of the Saros, or cycle of
+  eclipses--over 19 years--was "within 19-1/2 minutes of the
+  truth."--DRAPER.
+
+A rude method of printing with an engraved roller on plastic clay,
+afterward baked, thus making up ceramic libraries, was practised long
+previous to this time; and in the alcoves in which Hero worked were
+many of these books of clay.
+
+This great Library and Museum of Alexandria was founded three
+centuries before the birth of Christ, by Ptolemy Soter, who
+established as his capital that great Egyptian city when the death of
+his brother, the youthful but famous conqueror whose name he gave it,
+placed him upon the throne of the colossal successor of the then
+fallen Persian Empire. The city itself, embellished with every
+ornament and provided with every luxury that the wealth of a conquered
+world or the skill, taste, and ingenuity of the Greek painters,
+sculptors, architects, and engineers could provide, was full of
+wonders; it was a wonder in itself. This rich, populous, and
+magnificent city was the metropolis of the then civilized world.
+Trade, commerce, manufactures, and the fine arts were all represented
+in this splendid exchange, and learning found its most acceptable
+home and noblest field within the walls of Ptolemy's Museum; its
+disciples found themselves welcomed and protected by its founder and
+his successors, Philadelphus and the later Ptolemies.
+
+The Alexandrian Museum was founded with the declared object of
+collecting all written works of authority, of promoting the study of
+literature and art, and of stimulating and assisting experimental and
+mathematical scientific investigation and research. The founders of
+modern libraries, colleges, and technical schools have their prototype
+in intelligence, public spirit, and liberality, in the first of the
+Ptolemies, who not only spent an immense sum in establishing this
+great institution, but spared no expense in sustaining it. Agents were
+sent out into all parts of the world, purchasing books. A large staff
+of scribes was maintained at the museum, whose duty it was to multiply
+copies of valuable works, and to copy for the library such works as
+could not be purchased.
+
+The faculty of the museum was as carefully organized as was the plan
+of its administration. The four principal faculties of astronomy,
+literature, mathematics, and medicine were subdivided into sections
+devoted to the several branches of each department. The collections of
+the museum were as complete as the teachers of the undeveloped
+sciences of the time could make them. Lectures were given in all
+branches of study, and the number of students was sometimes as great
+as twelve or thirteen thousand. The number of books which were
+collected here, when the barbarian leaders of the Roman troops under
+Caesar burned the greater part of it, was stated to be 700,000. Of
+these, 400,000 were within the museum itself, and were all destroyed;
+the rest were in the temple of Serapis, and, for the time, escaped
+destruction.
+
+The greatest of all the great men who lived at Alexandria at the time
+of the establishment of the museum was Aristotle, the teacher of
+Alexander and the friend of Ptolemy. It is to Aristotle that we owe
+the systematization of the philosophical ideas of Plato and the
+creation of the inductive method, in which has originated all modern
+science. It is to the learned men of Alexandria that we are indebted
+for so effective an application of the Aristotelian philosophy that
+all the then known sciences were given form, and were so thoroughly
+established that the work of modern science has been purely one of
+development.
+
+The inductive method, which built up all the older sciences, and which
+has created all those of recent development, consists, first, in the
+discovery and quantitative determination of facts; secondly, when a
+sufficient number of facts have been thus observed and defined, in the
+grouping of those facts, and the detection, by a study of their mutual
+relations, of the natural laws which give rise to or regulate them.
+This simple method is that--and the only--method by which science
+advances. By this method, and by it only, do we acquire connected and
+systematic knowledge of all the phenomena of Nature of which the
+physical sciences are cognizant. It is only by the application of this
+Aristotelian method and philosophy that we can hope to acquire exact
+scientific knowledge of existing phenomena, or to become able to
+anticipate the phenomena which are to distinguish the future. The
+Aristotelian method of observing facts, and of inductive reasoning
+with those facts as a basis, has taught the chemist the properties of
+the known elementary substances and their characteristic behavior
+under ascertained conditions, and has taught him the laws of
+combination and the effects of their union, enabling him to predict
+the changes and the phenomena, chemical and physical, which inevitably
+follow their contact under any specified set of conditions.
+
+It is this process which has enabled the physicist to ascertain the
+methods of molecular motion which give us light, heat, or electricity,
+and the range of action and the laws which govern the transfer of
+energy from one of these modes of motion to another. It was this
+method of study which enabled James Watt to detect and to remedy the
+defects of the Newcomen engine, and it is by the Aristotelian
+philosophy that the engineer of to-day is taught to construct the
+modern steamship, and to predict, before the keel is laid or a blow
+struck in the workshop or the ship-yard, what will be the weight of
+the vessel, its cargo-carrying capacity, the necessary size and power
+of its engines, the quantity of coal which they will require per day
+while crossing the ocean, the depth at which the great hull will float
+in the water, and the exact speed that the vessel will attain when the
+engines are exerting their thousand or their ten thousand horse-power.
+
+It was at Alexandria that this mighty philosophy was first given a
+field in which to work effectively. Here Ptolemy studied astronomy and
+"natural philosophy;" Archimedes applied himself to the studies which
+attract the mathematician and engineer; Euclid taught his royal pupil
+those elements of geometry which have remained standard twenty-two
+centuries; Eratosthenes and Hipparchus studied and taught astronomy,
+and inaugurated the existing system of quantitative investigation,
+proving the spherical form of the earth; and Ctesibius and Hero
+studied pneumatics and experimented with the germs of the steam-engine
+and of less important machines.
+
+When, seven centuries later, the destruction of this splendid
+institution was signalized by the death of that brilliant scholar and
+heathen teacher of philosophy, Hypatia, at the hands of the more
+heathenish fanatics who tore her in pieces at the foot of the cross,
+and by the dispersion of the library left by Caesar's soldiers in the
+Serapeum, a true philosophy had been created, and the inductive method
+was destined to live and to overcome every obstacle in the path of
+enlightenment and civilization. The fall of the Alexandrian Museum,
+sad as was the event, could not destroy the new philosophical method.
+Its fruits ripened slowly but surely, and we are to-day gathering a
+plentiful harvest.
+
+Science, literature, and the arts, all remained dormant for several
+centuries after the catastrophe which deprived them of the light in
+which they had flourished so many centuries. The armies of the caliphs
+made complete the shameful work of destruction begun by the armies of
+Caesar, and the Alexandrian Library, partly destroyed by the Romans,
+was completely dispersed by the Patriarchs and their ignorant and
+fanatical followers; and finally all the scattered remnants were
+burned by the Saracens. But when the thirst for conquest had become
+satiated or appeased, the followers of the caliphs turned their
+attention to intellectual pursuits, and the ninth century of the
+Christian era saw once more such a collection of philosophical
+writings, collected at Bagdad, as could only be gathered by the power
+and wealth of the later conquerors of the world. Philosophy once again
+resumed its empire, and another race commenced the study of the
+mathematics of India and of Greece, the astronomy of Chaldea, and of
+all the sciences which originated in Greece and in Egypt. By the
+conquest of Spain by the Saracens, the new civilization was imported
+into Western Europe and libraries were gathered together under the
+Moorish rulers, one of which numbered more than a half-million
+volumes. Wherever Saracen armies had extended Mohammedan rule,
+schools and colleges, libraries and collections of philosophical
+apparatus, were scattered in strange profusion; and students,
+teachers, philosophers, of all--the speculative as well as the
+Aristotelian--schools, gathered together at these intellectual
+ganglia, as enthusiastic in their work as were their Alexandrian
+predecessors. The endowment of colleges, that truest gauge of the
+intelligence of the wealthy classes of any community, became as
+common--perhaps more so--as at the present time, and provision was
+made for the education of rich and poor alike. The mathematical
+sciences, and the wonderful and beautiful phenomena which--but a
+thousand years later--were afterward grouped into a science and called
+chemistry, were especially attractive to the Arabian scholars, and
+technical applications of discovered facts and laws assisted in a
+wonderfully rapid development of arts and manufactures.
+
+When, a thousand years after Christ, the centre of intellectual
+activity and of material civilization had drifted westward into
+Andalusia, the foundation of every modern physical science except that
+now just taking shape--the all-grasping science of energetics--had
+been laid with experimentally derived facts; and in mathematics there
+had been erected a symmetrical and elegant superstructure. Even that
+underlying principle of all the sciences, the principle of the
+persistence of energy, had been, perhaps unwittingly, enunciated.
+
+Distinguished historians have shown how the progress of civilization
+in Europe resulted in the creation, during the middle ages, of the now
+great middle class, which, holding the control of political power,
+governs every civilized nation, and has come into power so gradually
+that it was only after centuries that its influence was seen and felt.
+This, which Buckle[104] calls the intellectual class, first became
+active, independently of the military and of the clergy, in the
+fourteenth century. In the two succeeding centuries this class gained
+power and influence; and in the seventeenth century we find a
+magnificent advance in all branches of science, literature, and art,
+marking the complete emancipation of the intellect from the artificial
+conditions which had so long repressed its every effort at
+advancement.
+
+  [104] "History of Civilization in England," vol. i., p. 208. London,
+  1868.
+
+Another great social revolution thus occurred, following another
+period of centuries of intellectual stagnation. The Saracen invaders
+were driven from Europe; the Crusaders invaded Palestine, in the vain
+effort to recover from the hands of the infidels the Holy Sepulchre
+and the Holy Land; and intestine broils and inter-state conflicts, as
+well as these greater social movements, withdrew the minds of men once
+more from the arts of peace and the pursuits of scholars. It is not,
+then, until the beginning of the seventeenth century--the time of
+Galileo and of Newton--that we find the nations of Europe sufficiently
+quiet and secure to permit general attention to intellectual
+vocations, although it was a half-century earlier (1543) that
+Copernicus left to the world that legacy which revolutionized the
+theories of the astronomers and established as correct the hypothesis
+which made the sun the centre of the solar system.
+
+Galileo now began to overturn the speculations of the deductive
+philosophers, and to proclaim the still disputed principle that the
+book of Nature is a trustworthy commentary in the study of theological
+and revealed truths, so far as they affect or are affected by science;
+he suffered martyrdom when he proclaimed the fact that God's laws, as
+they now stand, had been instituted without deference to the
+preconceived notions of the most ignorant of men. Bruno had a few
+years earlier (1600) been burned at the stake for a similar offense.
+
+Galileo was perhaps the first, too, to combine invariably in
+application the idea of Plato, the philosophy of Aristotle, and the
+methods of modern experimentation, to form the now universal
+scientific method of experimental philosophy. He showed plainly how
+the grouping of ascertained facts, in natural sequence, leads to the
+revelation of the law of that sequence, and indicated the existence of
+a principle which is now known as the law of continuity--the law that
+in all the operations of Nature there is to be seen an unbroken chain
+of effect leading from the present back into a known or an unknown
+past, toward a cause which may or may not be determinable by science
+or known to history.
+
+Galileo, the Italian, was worthily matched by Newton, the prince of
+English philosophers. The science of theoretical mechanics was hardly
+beginning to assume the position which it was afterward given among
+the sciences; and the grand work of collating facts already
+ascertained, and of definitely stating principles which had previously
+been vaguely recognized, was splendidly done by Newton. The needs of
+physical astronomy urged this work upon him.
+
+Da Vinci had, in the latter half of the fifteenth century, summarized
+as much of the statics of mechanical philosophy as had, up to his
+time, been given shape; he also rewrote and added very much to what
+was known on the subject of friction, and enunciated its laws. He had
+evidently a good idea of the principle of "virtual velocities," that
+simple case of equivalence of work, in a connected system, which has
+done such excellent service since; and with his mechanical philosophy
+this versatile engineer and artist curiously mingled much of physical
+science. Then Stevinus, the "brave engineer of Bruges," a hundred
+years later (1586), alternating office and field work, somewhat after
+the manner of the engineer of to-day, wrote a treatise on mechanics,
+which showed the value of practical experience and judgment in even
+scientific work. And thus the path had been cleared for Newton.
+
+Meantime, also, Kepler had hit upon the true relations of the
+distances of the planets and their periodic times, after spending half
+a generation in blindly groping for them, thus furnishing those great
+landmarks of fact in the mechanics of astronomy; and Galileo had
+enunciated the laws of motion. Thus the foundation of the science of
+dynamics, as distinguished from statics, was laid, and the beginning
+was made of that later science of energetics, of which the philosophy
+of the steam-engine is so largely constituted.
+
+Hooke, Huyghens, and others, had already seen some of the principal
+consequences of these laws; but it remained for Newton to enunciate
+them with the precision of a true mathematician, and to base upon them
+a system of dynamical laws, which, complemented by his announcement of
+the existence of the force of gravitation, and his statement of its
+laws, gave a firm basis for all that the astronomer has since done in
+those quantitative determinations of size, weight, and distance, and
+of the movements of the heavenly bodies, which compel the wonder and
+admiration of mankind.
+
+The Arabians and Greeks had noticed that the direction taken by a body
+falling under the action of gravitation was directly toward the centre
+of the earth, wherever its fall might occur; Galileo had shown, by his
+experiments at Pisa, that the velocity of fall, second after second,
+varied as the numbers 1, 3, 5, 7, 9, etc., and that the distances
+varied as the squares of the total periods of time during which the
+body was falling, and that it was, in British feet, very nearly
+sixteen times the square of that time in seconds. Kepler had proved
+that the movements of the heavenly bodies were just such as would
+occur under the action of central attractive forces and of centrifugal
+force.
+
+Putting all these things together, Newton was led to believe that
+there existed a "force of gravity," due to the attraction, by the
+great mass of the earth, of its own particles and of neighboring
+bodies, like the moon, of which force the influence extended as far,
+at least, as the latter. He calculated the motion of the earth's
+satellite, on the assumption that his theory and the then accepted
+measurements of the earth's dimensions were correct, and obtained a
+roughly approximate result. Later, in 1679, he revised his
+calculations, using Picard's more accurate determination of the
+dimensions of the earth, and obtained a result which precisely tallied
+with careful measurements, made by the astronomers, of the moon's
+motion.
+
+The science of mechanics had now, with the publication of Newton's
+"Principia," become thoroughly consistent and logically complete, so
+far as was possible without a knowledge of the principles of
+energetics; and Newton's enunciations of the laws of motion, concise
+and absolutely perfect as they still seem, were the basis of the whole
+science of dynamics, as applied to bodies moving freely under the
+action of applied forces, either constant or variable. They are as
+perfect a basis for that science as are the primary principles of
+geometry for the whole beautiful structure which is built up on them.
+
+The three perfect qualitative expressions of dynamical law are:
+
+1. Every free body continues in the state in which it may be, whether
+of rest or of rectilinear uniform motion, until compelled to deviate
+from that state by impressed forces.
+
+2. Change of motion is proportional to the force impressed, and in the
+direction of the right line in which that force acts.
+
+3. Action is always opposed by reaction; action and reaction are
+equal, and in directly contrary directions.
+
+We may add to these principles a definition of a force, which is
+equally and absolutely complete:
+
+_Force_ is that which produces, or tends to produce, motion, or change
+of motion, in bodies. It is measured statically by the weight that
+will counterpoise it, or by the pressure which it will produce, and
+dynamically by the velocity which it will produce, acting in the unit
+of time on the unit of mass.
+
+The quantitative determinations of dynamic effects of forces are
+always readily made when it is remembered that the effect of a force
+equal to its own weight, when the body is free to move, is to produce
+in one second a velocity of 32.2 feet per second, which quantity is
+the unit of dynamic measurement.
+
+_Work_ is the product of the resistance met in any instance of the
+exertion of a force, into the distance through which that force
+overcomes the resistance.
+
+_Energy_ is the work which a body is capable of doing, by its weight
+or inertia, under given conditions. The energy of a falling body, or
+of a flying shot, is about 1/64 its weight multiplied by the square of
+its velocity, or, which is the same thing, the product of its weight
+into the height of fall or height due its velocity. These principles
+and definitions, with the long-settled definitions of the primary
+ideas of space and time, were all that were needed to lead the way to
+that grandest of all physical generalizations, the doctrine of the
+persistence or conservation of all energy, and to its corollary
+declaring the equivalence of all forms of energy, and also to the
+experimental demonstration of the transformability of energy from one
+mode of existence to another, and its universal existence in the
+various modes of motion of bodies and of their molecules.
+
+Experimental physical science had hardly become acknowledged as the
+only and the proper method of acquiring knowledge of natural phenomena
+at the time of Newton; but it soon became a generally accepted
+principle. In physics, Gilbert had made valuable investigations before
+Newton, and Galileo's experiments at Pisa had been examples of
+similarly useful research. In chemistry, it was only when, a century
+later, Lavoisier showed by his splendid example what could be done by
+the skillful and intelligent use of quantitative measurements, and
+made the balance the chemist's most important tool, that a science was
+formed comprehending all the facts and laws of chemical change and
+molecular combination. We have already seen how astronomy and
+mathematics together led philosophers to the creation and the study of
+what finally became the science of mechanics, when experiment and
+observation were finally brought to their aid. We can now see how, in
+all these physical sciences, four primitive ideas are comprehended:
+matter, force, motion, and space--which latter two terms include all
+relations of position.
+
+Based on these notions, the science of mechanics comprehends four
+sections, which are of general application in the study of all
+physical phenomena. These are:
+
+_Statics_, which treats of the action and effect of forces.
+
+_Kinematics_, which treats of relations of motion simply.
+
+_Dynamics_, or kinetics, which treats of simple motion as an effect of
+the action of forces.
+
+_Energetics_, which treats of modifications of energy under the action
+of forces, and of its transformation from one mode of manifestation to
+another, and from one body to another.
+
+Under the latter of these four divisions of mechanical philosophy is
+comprehended that latest of the minor sciences, of which the
+heat-engines, and especially the steam-engine, illustrate the most
+important applications--_Thermo-dynamics_. This science is simply a
+wider generalization of principles which, as we have seen, have been
+established one at a time, and by philosophers widely separated both
+geographically and historically, by both space and time, and which
+have been slowly aggregated to form one after another of the sciences,
+and out of which, as we now are beginning to see, we are slowly
+evolving wider generalizations, and thus tending toward a condition of
+scientific knowledge which renders more and more probable the truth of
+Cicero's declaration: "One eternal and immutable law embraces all
+things and all times." At the basis of the whole science of energetics
+lies a principle which was enunciated before Science had a birthplace
+or a name:
+
+_All that exists, whether matter or force, and in whatever form, is
+indestructible, except by the Infinite Power which has created it._
+
+That matter is indestructible by finite power became admitted as soon
+as the chemists, led by their great teacher Lavoisier, began to apply
+the balance, and were thus able to show that in all chemical change
+there occurs only a modification of form or of combination of
+elements, and no loss of matter ever takes place. The "persistence" of
+energy was a later discovery, consequent largely upon the experimental
+determination of the convertibility of heat-energy into other forms
+and into mechanical work, for which we are indebted to Rumford and
+Davy, and to the determination of the quantivalence anticipated by
+Newton, shown and calculated approximately by Colding and Mayer, and
+measured with great probable accuracy by Joule.
+
+[Illustration: Benjamin Thompson, Count Rumford.]
+
+The great fact of the conservation of energy was loosely stated by
+Newton, who asserted that the work of friction and the _vis viva_ of
+the system or body arrested by friction were equivalent. In 1798,
+Benjamin Thompson, Count Rumford, an American who was then in the
+Bavarian service, presented a paper[105] to the Royal Society of Great
+Britain, in which he stated the results of an experiment which he had
+recently made, proving the immateriality of heat and the
+transformation of mechanical into heat energy. This paper is of very
+great historical interest, as the now accepted doctrine of the
+persistence of energy is a generalization which arose out of a series
+of investigations, the most important of which are those which
+resulted in the determination of the existence of a definite
+quantivalent relation between these two forms of energy and a
+measurement of its value, now known as the "mechanical equivalent of
+heat." His experiment consisted in the determination of the quantity
+of heat produced by the boring of a cannon at the arsenal at Munich.
+
+  [105] "Philosophical Transactions," 1798.
+
+Rumford, after showing that this heat could not have been derived from
+any of the surrounding objects, or by compression of the materials
+employed or acted upon, says: "It appears to me extremely difficult,
+if not impossible, to form any distinct idea of anything capable of
+being excited and communicated in the manner that heat was excited and
+communicated in these experiments, except it be motion."[106] He then
+goes on to urge a zealous and persistent investigation of the laws
+which govern this motion. He estimates the heat produced by a power
+which he states could easily be exerted by one horse, and makes it
+equal to the "combustion of nine wax candles, each three-quarters of
+an inch in diameter," and equivalent to the elevation of "25.68 pounds
+of ice-cold water" to the boiling-point, or 4,784.4 heat-units.[107]
+The time was stated at "150 minutes." Taking the actual power of
+Rumford's Bavarian "one horse" as the most probable figure, 25,000
+pounds raised one foot high per minute,[108] this gives the
+"mechanical equivalent" of the foot-pound as 783.8 heat-units,
+differing but 1.5 per cent. from the now accepted value.
+
+  [106] This idea was not by any means original with Rumford. Bacon
+  seems to have had the same idea; and Locke says, explicitly enough:
+  "Heat is a very brisk agitation of the insensible parts of the
+  object ... so that what in our sensation is heat, in the object is
+  nothing but motion."
+
+  [107] The British heat-unit is the quantity of heat required to heat
+  one pound of water 1 deg. Fahr. from the temperature of maximum density.
+
+  [108] Rankine gives 25,920 foot-pounds per minute--or 432 per
+  second--for the average draught-horse in Great Britain, which is
+  probably too high for Bavaria. The engineer's "horse-power"--33,000
+  foot-pounds per minute--is far in excess of the average power of
+  even a good draught-horse, which latter is sometimes taken as
+  two-thirds the former.
+
+Had Rumford been able to eliminate all losses of heat by evaporation,
+radiation, and conduction, to which losses he refers, and to measure
+the power exerted with accuracy, the approximation would have been
+still closer. Rumford thus made the experimental discovery of the real
+nature of heat, proving it to be a form of energy, and, publishing
+the fact a half-century before the now standard determinations were
+made, gave us a very close approximation to the value of the
+heat-equivalent. Rumford also observed that the heat generated was
+"exactly proportional to the force with which the two surfaces are
+pressed together, and to the rapidity of the friction," which is a
+simple statement of equivalence between the quantity of work done, or
+energy expended, and the quantity of heat produced. This was the first
+great step toward the formation of a Science of Thermo-dynamics.
+Rumford's work was the corner-stone of the science.
+
+Sir Humphry Davy, a little later (1799), published the details of an
+experiment which conclusively confirmed these deductions from
+Rumford's work. He rubbed two pieces of ice together, and found that
+they were melted by the friction so produced. He thereupon concluded:
+"It is evident that ice by friction is converted into water....
+Friction, consequently, does not diminish the capacity of bodies for
+heat."
+
+Bacon and Newton, and Hooke and Boyle, seem to have anticipated--long
+before Rumford's time--all later philosophers, in admitting the
+probable correctness of that modern dynamical, or vibratory, theory of
+heat which considers it a mode of motion; but Davy, in 1812, for the
+first time, stated plainly and precisely the real nature of heat,
+saying: "The immediate cause of the phenomenon of heat, then, is
+motion, and the laws of its communication are precisely the same as
+the laws of the communication of motion." The basis of this opinion
+was the same that had previously been noted by Rumford.
+
+So much having been determined, it became at once evident that the
+determination of the exact value of the mechanical equivalent of heat
+was simply a matter of experiment; and during the succeeding
+generation this determination was made, with greater or less
+exactness, by several distinguished men. It was also equally evident
+that the laws governing the new science of thermo-dynamics could be
+mathematically expressed.
+
+Fourier had, before the date last given, applied mathematical analysis
+in the solution of problems relating to the transfer of heat without
+transformation, and his "Theorie de la Chaleur" contained an
+exceedingly beautiful treatment of the subject. Sadi Carnot, twelve
+years later (1824), published his "Reflexions sur la Puissance Motrice
+du Feu," in which he made a first attempt to express the principles
+involved in the application of heat to the production of mechanical
+effect. Starting with the axiom that a body which, having passed
+through a series of conditions modifying its temperature, is returned
+to "its primitive physical state as to density, temperature, and
+molecular constitution," must contain the same quantity of heat which
+it had contained originally, he shows that the efficiency of
+heat-engines is to be determined by carrying the working fluid through
+a complete cycle, beginning and ending with the same set of
+conditions. Carnot had not then accepted the vibratory theory of heat,
+and consequently was led into some errors; but, as will be seen
+hereafter, the idea just expressed is one of the most important
+details of a theory of the steam-engine.
+
+Seguin, who has already been mentioned as one of the first to use the
+fire-tubular boiler for locomotive engines, published in 1839 a work,
+"Sur l'Influence des Chemins de Fer," in which he gave the requisite
+data for a rough determination of the value of the mechanical
+equivalent of heat, although he does not himself deduce that value.
+
+Dr. Julius R. Mayer, three years later (1842), published the results
+of a very ingenious and quite closely approximate calculation of the
+heat-equivalent, basing his estimate upon the work necessary to
+compress air, and on the specific heats of the gas, the idea being
+that the work of compression is the equivalent of the heat generated.
+Seguin had taken the converse operation, taking the loss of heat of
+expanding steam as the equivalent of the work done by the steam while
+expanding. The latter also was the first to point out the fact,
+afterward experimentally proved by Hirn, that the fluid exhausted from
+an engine should heat the water of condensation less than would the
+same fluid when originally taken into the engine.
+
+A Danish engineer, Colding, at about the same time (1843), published
+the results of experiments made to determine the same quantity; but
+the best and most extended work, and that which is now almost
+universally accepted as standard, was done by a British investigator.
+
+James Prescott Joule commenced the experimental investigations which
+have made him famous at some time previous to 1843, at which date he
+published, in the _Philosophical Magazine_, his earliest method. His
+first determination gave 770 foot-pounds. During the succeeding five
+or six years Joule repeated his work, adopting a considerable variety
+of methods, and obtaining very variable results. One method was to
+determine the heat produced by forcing air through tubes; another, and
+his usual plan, was to turn a paddle-wheel by a definite power in a
+known weight of water. He finally, in 1849, concluded these
+researches.
+
+[Illustration: James Prescott Joule.]
+
+The method of calculating the mechanical equivalent of heat which was
+adopted by Dr. Mayer, of Heilbronn, is as beautiful as it is
+ingenious: Conceive two equal portions of atmospheric air to be
+inclosed, at the same temperature--as at the freezing-point--in
+vessels each capable of containing one cubic foot; communicate heat to
+both, retaining the one portion at the original volume, and permitting
+the other to expand under a constant pressure equal to that of the
+atmosphere. In each vessel there will be inclosed 0.08073 pound, or
+1.29 ounce, of air. When, at the same temperature, the one has doubled
+its pressure and the other has doubled its volume, each will be at a
+temperature of 525.2 deg. Fahr., or 274 deg. C, and each will have double the
+original temperature, as measured on the absolute scale from the zero
+of heat-motion. But the one will have absorbed but 6-3/4 British
+thermal units, while the other will have absorbed 9-1/2. In the first
+case, all of this heat will have been employed in simply increasing
+the temperature of the air; in the second case, the temperature of the
+air will have been equally increased, and, besides, a certain amount
+of work--2,116.3 foot-pounds--must have been done in overcoming the
+resistance of the air; it is to this latter action that we must debit
+the additional heat which has disappeared. Now, 2,116.3/(2-3/4) = 770
+foot-pounds per heat-unit--almost precisely the value derived from
+Joule's experiments. Had Mayer's measurement been absolutely accurate,
+the result of his calculation would have been an exact determination
+of the heat-equivalent, provided no heat is, in this case, lost by
+internal work.
+
+Joule's most probably accurate measure was obtained by the use of a
+paddle-wheel revolving in water or other fluid. A copper vessel
+contained a carefully weighed portion of the fluid, and at the bottom
+was a step, on which stood a vertical spindle carrying the
+paddle-wheel. This wheel was turned by cords passing over
+nicely-balanced grooved wheels, the axles of which were carried on
+friction-rollers. Weights hung at the ends of these cords were the
+moving forces. Falling to the ground, they exerted an easily and
+accurately determinable amount of work, _W_ x _H_, which turned the
+paddle-wheel a definite number of revolutions, warming the water by
+the production of an amount of heat exactly equivalent to the amount
+of work done. After the weight had been raised and this operation
+repeated a sufficient number of times, the quantity of heat
+communicated to the water was carefully determined and compared with
+the amount of work expended in its development. Joule also used a pair
+of disks of iron rubbing against each other in a vessel of mercury,
+and measured the heat thus developed by friction, comparing it with
+the work done. The average of forty experiments with water gave the
+equivalent 772.692 foot-pounds; fifty with mercury gave 774.083;
+twenty with cast-iron gave 774.987--the temperature of the apparatus
+being from 55 deg. to 60 deg. Fahr.
+
+Joule also determined, by experiment, the fact that the expansion of
+air or other gas without doing work produces no change of temperature,
+which fact is predicable from the now known principles of
+thermo-dynamics. He stated the results of his researches relating to
+the mechanical equivalent of heat as follows:
+
+1. The heat produced by the friction of bodies, whether solid or
+liquid, is always proportional to the quantity of work expended.
+
+2. The quantity required to increase the temperature of a pound of
+water (weighed _in vacuo_ at 55 deg. to 60 deg. Fahr.) by one degree requires
+for its production the expenditure of a force measured by the fall of
+772 pounds from a height of one foot. This quantity is now generally
+called "Joule's equivalent."
+
+During this series of experiments, Joule also deduced the position of
+the "absolute zero," the point at which heat-motion ceases, and stated
+it to be about 480 deg. Fahr. below the freezing-point of water, which is
+not very far from the probably true value,-493.2 deg. Fahr. (-273 deg. C.), as
+deduced afterward from more precise data.
+
+The result of these, and of the later experiments of Hirn and others,
+has been the admission of the following principle:
+
+Heat-energy and mechanical energy are mutually convertible and have a
+definite equivalence, the British thermal unit being equivalent to 772
+foot-pounds of work, and the metric _calorie_ to 423.55, or, as
+usually taken, 424 kilogrammetres. The exact measure is not fully
+determined, however.
+
+It has now become generally admitted that all forms of energy due to
+physical forces are mutually convertible with a definite
+quantivalence; and it is not yet determined that even vital and mental
+energy do not fall within the same great generalization. This
+quantivalence is the sole basis of the science of Energetics.
+
+The study of this science has been, up to the present time,
+principally confined to that portion which comprehends the relations
+of heat and mechanical energy. In the study of this department of the
+science, thermo-dynamics, Rankine, Clausius, Thompson, Hirn, and
+others have acquired great distinction. In the investigations which
+have been made by these authorities, the methods of transfer of heat
+and of modification of physical state in gases and vapors, when a
+change occurs in the form of the energy considered, have been the
+subjects of especial study.
+
+According to the law of Boyle and Marriotte, the expansion of such
+fluids follows a law expressed graphically by the hyperbola, and
+algebraically by the expression PV^{_x_} = A, in which, with
+unchanging temperature, _x_ is equal to 1. One of the first and most
+evident deductions from the principles of the equivalence of the
+several forms of energy is that the value of x must increase as the
+energy expended in expansion increases. This change is very marked
+with a vapor like steam--which, expanded without doing work, has an
+exponent less than unity, and which, when doing work by expanding
+behind a piston, partially condenses, the value of _x_ increases to,
+in the case of steam, 1.111 according to Rankine, or, probably more
+correctly, to 1.135 or more, according to Zeuner and Grashof. This
+fact has an important bearing upon the theory of the steam-engine, and
+we are indebted to Rankine for the first complete treatise on that
+theory as thus modified.
+
+Prof. Rankine began his investigations as early as 1849, at which time
+he proposed his theory of the molecular constitution of matter, now
+well known as the theory of molecular vortices. He supposes a system
+of whirling rings or vortices of heat-motion, and bases his
+philosophy upon that hypothesis, supposing sensible heat to be
+employed in changing the velocity of the particles, latent heat to be
+the work of altering the dimensions of the orbits, and considering the
+effort of each vortex to enlarge its boundaries to be due to
+centrifugal force. He distinguished between real and apparent specific
+heat, and showed that the two methods of absorption of heat, in the
+case of the heating of a fluid, that due to simple increase of
+temperature and that due to increase of volume, should be
+distinguished; he proposed, for the latter quantity, the term
+heat-potential, and for the sum of the two, the name of thermo-dynamic
+function.
+
+[Illustration: Prof. W. J. M. Rankine.]
+
+Carnot had stated, a quarter of a century earlier, that the efficiency
+of a heat-engine is a function of the two limits of temperature
+between which the machine is worked, and not of the nature of the
+working substance--an assertion which is quite true where the material
+does not change its physical state while working. Rankine now deduced
+that "general equation of thermo-dynamics" which expresses
+algebraically the relations between heat and mechanical energy, when
+energy is changing from the one state to the other, in which equation
+is given, for any assumed change of the fluids, the quantity of heat
+transformed. He showed that steam in the engine must be partially
+liquefied by the process of expanding against a resistance, and proved
+that the total heat of a perfect gas must increase with rise of
+temperature at a rate proportional to its specific heat under constant
+pressure.
+
+Rankine, in 1850, showed the inaccuracy of the then accepted value,
+0.2669, of the specific heat of air under constant pressure, and
+calculated its value as 0.24. Three years later, the experiments of
+Regnault gave the value 0.2379, and Rankine, recalculating it, made it
+0.2377. In 1851, Rankine continued his discussion of the subject, and,
+by his own theory, corroborated Thompson's law giving the efficiency
+of a perfect heat-engine as the quotient of the range of working
+temperature to the temperature of the upper limit, measured from the
+absolute zero.
+
+During this period, Clausius, the German physicist, was working on the
+same subject, taking quite a different method, studying the mechanical
+effects of heat in gases, and deducing, almost simultaneously with
+Rankine (1850), the general equation which lies at the beginning of
+the theory of the equivalence of heat and mechanical energy. He found
+that the probable zero of heat-motion is at such a point that the
+Carnot function must be approximately the reciprocal of the "absolute"
+temperature, as measured with the air thermometer, or, stated exactly,
+that quantity as determined by a perfect gas thermometer. He confirmed
+Rankine's conclusion relative to the liquefaction of saturated vapors
+when expanding against resistance, and, in 1854, adapted Carnot's
+principle to the new theory, and showed that his idea of the
+reversible engine and of the performance of a cycle in testing the
+changes produced still held good, notwithstanding Carnot's ignorance
+of the true nature of heat. Clausius also gave us the extremely
+important principle: It is impossible for a self-acting machine,
+unaided, to transfer heat from one body at a low temperature to
+another having a higher temperature.
+
+Simultaneously with Rankine and Clausius, Prof. William Thomson was
+engaged in researches in thermo-dynamics (1850). He was the first to
+express the principle of Carnot as adapted to the modern theory by
+Clausius in the now generally quoted propositions:[109]
+
+  [109] _Vide_ Tait's admirable "Sketch of Thermodynamics," second
+  edition, Edinburgh, 1877.
+
+1. When equal mechanical effects are produced by purely thermal
+action, equal quantities of heat are produced or disappear by
+transformation of energy.
+
+2. If, in any engine, a reversal effects complete inversion of all the
+physical and mechanical details of its operation, it is a perfect
+engine, and produces maximum effect with any given quantity of heat
+and with any fixed limits of range of temperature.
+
+William Thomson and James Thompson showed, among the earliest of their
+deductions from these principles, the fact, afterward confirmed by
+experiment, that the melting-point of ice should be lowered by
+pressure 0.0135 deg. Fahr, for each atmosphere, and that a body which
+contracts while being heated will always have its temperature
+decreased by sudden compression. Thomson applied the principles of
+energetics in extended investigations in the department of
+electricity, while Helmholtz carried some of the same methods into his
+favorite study of acoustics.
+
+The application of now well-settled principles to the physics of gases
+led to many interesting and important deductions: Clausius explained
+the relations between the volume, density, temperature, and pressure
+of gases, and their modifications; Maxwell reestablished the
+experimentally determined law of Dalton and Charles, known also as
+that of Gay-Lussac (1801), which asserts that all masses of equal
+pressure, volume, and temperature, contain equal numbers of molecules.
+On the Continent of Europe, also, Hirn, Zeuner, Grashof, Tresca,
+Laboulaye, and others have, during the same period and since,
+continued and greatly extended these theoretical researches.
+
+During all this time, a vast amount of experimental work has also been
+done, resulting in the determination of important data without which
+all the preceding labor would have been fruitless. Of those who have
+engaged in such work, Cagniard de la Tour, Andrews, Regnault, Hirn,
+Fairbairn and Tate, Laboulaye, Tresca, and a few others have directed
+their researches in this most important direction with the special
+object of aiding in the advancement of the new-born sciences. By the
+middle of the present century, the time which we are now studying,
+this set of data was tolerably complete. Boyle had, two hundred years
+before, discovered and published the law, which is now known by his
+name[110] and by that of Marriotte,[111] that the pressure of a gas
+varies inversely as its volume and directly as its density; Dr. Black
+and James Watt discovered, a hundred years later (1760), the latent
+heat of vapors, and Watt determined the method of expansion of steam;
+Dalton, in England, and Gay-Lussac, in France, showed, at the
+beginning of the nineteenth century, that all gaseous fluids are
+expanded by equal fractions of their volume by equal increments of
+temperature; Watt and Robison had given tables of the elastic force of
+steam, and Gren had shown that, at the temperature of boiling water,
+the pressure of steam was equal to that of the atmosphere; Dalton,
+Ure, and others proved (1800-1818) that the law connecting
+temperatures and pressures of steam was expressed by a geometrical
+ratio; and Biot had already given an approximate formula, when
+Southern introduced another, which is still in use.
+
+  [110] "New Experiments, Physico-Mechanical, etc., touching the
+  Spring of Air," 1662.
+
+  [111] "De la Nature de l'Air," 1676.
+
+The French Government established a commission in 1823 to experiment
+with a view to the institution of legislation regulating the working
+of steam-engines and boilers; and this commission, MM. de Prony,
+Arago, Girard, and Dulong, determined quite accurately the
+temperatures of steam under pressures running up to twenty-four
+atmospheres, giving a formula for the calculation of the one quantity,
+the other being known. Ten years later, the Government of the United
+States instituted similar experiments under the direction of the
+Franklin Institute.
+
+The marked distinction between gases, like oxygen and hydrogen, and
+condensible vapors, like steam and carbonic acid, had been, at this
+time, shown by Cagniard de la Tour, who, in 1822, studied their
+behavior at high temperatures and under very great pressures. He found
+that, when a vapor was confined in a glass tube in presence of the
+same substance in the liquid state, as where steam and water were
+confined together, if the temperature was increased to a certain
+definite point, the whole mass suddenly became of uniform character,
+and the previously existing line of demarkation vanished, the whole
+mass of fluid becoming, as he inferred, gaseous. It was at about this
+time that Faraday made known his then novel experiments, in which
+gases which had been before supposed permanent were liquefied, simply
+by subjecting them to enormous pressures. He then also first stated
+that, above certain temperatures, liquefaction of vapors was
+impossible, however great the pressure.
+
+Faraday's conclusion was justified by the researches of Dr. Andrews,
+who has since most successfully extended the investigation commenced
+by Cagniard de la Tour, and who has shown that, at a certain point,
+which he calls the "critical point," the properties of the two states
+of the fluid fade into each other, and that, at that point, the two
+become continuous. With carbonic acid, this occurs at 75 atmospheres,
+about 1,125 pounds per square inch, a pressure which would
+counterbalance a column of mercury 60 yards, or nearly as many metres,
+high. The temperature at this point is about 90 deg. Fahr., or 31 deg. Cent.
+For ether, the temperature is 370 deg. Fahr., and the pressure 38
+atmospheres; for alcohol, they are 498 deg. Fahr., and 120 atmospheres;
+and for bisulphide of carbon, 505 deg. Fahr., and 67 atmospheres. For
+water, the pressure is too high to be determined; but the temperature
+is about 775 deg. Fahr., or 413 deg. Cent.
+
+Donny and Dufour have shown that these normal properties of vapors and
+liquids are subject to modification by certain conditions, as
+previously (1818) noted by Gay-Lussac, and have pointed out the
+bearing of this fact upon the safety of steam-boilers. It was
+discovered that the boiling-point of water could be elevated far above
+its ordinary temperature of ebullition by expedients which deprive the
+liquid of the air usually condensed within its mass, and which prevent
+contact with rough or metallic surfaces. By suspension in a mixture of
+oils which is of nearly the same density, Dufour raised drops of water
+under atmospheric pressure to a temperature of 356 deg. Fahr.--180 deg.
+Cent.--the temperature of steam of about 150 pounds per square inch.
+Prof. James Thompson has, on theoretical grounds, indicated that a
+somewhat similar action may enable vapor, under some conditions, to be
+cooled below the normal temperature of condensation, without
+liquefaction.
+
+Fairbairn and Tate repeated the attempt to determine the volume and
+temperature of water at pressures extending beyond those in use in the
+steam-engine, and incomplete determinations have also been made by
+others.
+
+Regnault is the standard authority on these data. His experiments
+(1847) were made at the expense of the French Government, and under
+the direction of the French Academy. They were wonderfully accurate,
+and extended through a very wide range of temperatures and pressures.
+The results remain standard after the lapse of a quarter of a century,
+and are regarded as models of precise physical work.[112]
+
+  [112] _See_ Porter on the Steam-Engine Indicator for the best set of
+  Regnault's tables generally accessible.
+
+Regnault found that the total heat of steam is not constant, but that
+the latent heat varies, and that the sum of the latent and sensible
+heats, or the total heat, increases 0.305 of a degree for each degree
+of increase in the sensible heat, making 0.305 the specific heat of
+saturated steam. He found the specific heat of superheated steam to be
+0.4805.
+
+Regnault promptly detected the fact that steam was not subject to
+Boyle's law, and showed that the difference is very marked. In
+expressing his results, he not only tabulated them but also laid them
+down graphically; he further determined exact constants for Biot's
+algebraic expression,
+
+  log. _p_ = _a_ - _b_A^{_x_} - _c_B^{_x_};
+
+making _x_ = 20 + _t_ deg. Cent.; _a_ = 6.264035; log. _b_ = 0.1397743;
+log. _c_ = 0.6924351; log. A = [=1].9940493, and log. B = [=1].9983439;
+_p_ is the pressure in atmospheres. Regnault, in the expression for the
+total heat, H = A + _bt_, determined on the centigrade scale [theta] =
+606.5 + 0.305 _t_ Cent. For the Fahrenheit scale, we have the
+following equivalent expressions:
+
+  H = 1,113.44 deg. + 0.305 _t_ deg. Fahr., if measured from 0 deg. Fahr.
+    = 1,091.9 deg.  + 0.305 (_t_ deg. - 32) Fahr.,;   } if measured from
+    = 1,081.94 deg. + 0.305 _t_ deg. Fahr.,           } the freezing-point.
+
+For latent heat, we have:
+
+  L = 606.5 deg. - 0.695 _t_ deg. Cent.
+    = 1,091.7 deg.- 0.695 (_t_ deg. - 32) Fahr.
+    = 1,113.94 deg.- 0.695 _t_ deg. Fahr.
+
+Since Regnault's time, nothing of importance has been done in this
+direction. There still remains much work to be done in the extension
+of the research to higher pressures, and under conditions which obtain
+in the operation of the steam-engine. The volumes and densities of
+steam require further study, and the behavior of steam in the engine
+is still but little known, otherwise than theoretically. Even the true
+value of Joule's equivalent is not undisputed.
+
+Some of the most recent experimental work bearing directly upon the
+philosophy of the steam-engine is that of Hirn, whose determination of
+the value of the mechanical equivalent was less than two per cent.
+below that of Joule. Hirn tested by experiment, in 1853, and
+repeatedly up to 1876, the analytical work of Rankine, which led to
+the conclusion that steam doing work by expansion must become
+gradually liquefied. Constructing a glass steam-engine cylinder, he
+was enabled to see plainly the clouds of mist which were produced by
+the expansion of steam behind the piston, where Regnault's experiments
+prove that the steam should become drier and superheated, were no heat
+transformed into mechanical energy. As will be seen hereafter, this
+great discovery of Rankine is more important in its bearing upon the
+theory of the steam-engine than any made during the century. Hirn's
+confirmation stands, in value, beside the original discovery. In 1858
+Hirn confirmed the work of Mayer and Joule by determining the work
+done and the carbonic acid produced, as well as the increased
+temperature due to their presence, where men were set at work in a
+treadmill; he found the elevation of temperature to be much greater in
+proportion to gas produced when the men were resting than when they
+were at work. He thus proved conclusively the conversion of
+heat-energy into mechanical work. It was from these experiments that
+Helmholtz deduced the "modulus of efficiency" of the human machine at
+one-fifth, and concluded that the heart works with eight times the
+efficiency of a locomotive-engine, thus confirming a statement of
+Rumford, who asserted the higher efficiency of the animal.
+
+Hirn's most important experiments in this department were made upon
+steam-engines of considerable size, including simple and compound
+engines, and using steam sometimes saturated and sometimes superheated
+to temperatures as high, on some occasions, as 340 deg. Cent. He
+determined the work done, the quantity of heat entering, and the
+amount rejected from, the steam-cylinder, and thus obtained a coarse
+approximation to the value of the heat-equivalent. His figure varied
+from 296 to 337 kilogrammetres. But, in all cases, the loss of heat
+due to work done was marked, and, while these researches could not, in
+the nature of the case, give accurate quantitative results, they are
+of great value as qualitatively confirming Mayer and Joule, and
+proving the transformation of energy.
+
+Thus, as we have seen, experimental investigation and analytical
+research have together created a new science, and the philosophy of
+the steam-engine has at last been given a complete and well-defined
+form, enabling the intelligent engineer to comprehend the operation of
+the machine, to perceive the conditions of efficiency, and to look
+forward in a well-settled direction for further advances in its
+improvement and in the increase of its efficiency.
+
+A very concise _resume_ of the principal facts and laws bearing upon
+the philosophy of the steam-engine will form a fitting conclusion to
+this historical sketch.
+
+The term "energy" was first used by Dr. Young as the equivalent of the
+work of a moving body, in his hardly yet obsolete "Lectures on Natural
+Philosophy."
+
+Energy is the capacity of a moving body to overcome resistance offered
+to its motion; it is measured either by the product of the mean
+resistance into the space through which it is overcome, or by the
+half-product of the mass of the body into the square of its velocity.
+Kinetic energy is the actual energy of a moving body; potential energy
+is the measure of the work which a body is capable of doing under
+certain conditions which, without expending energy, may be made to
+affect it, as by the breaking of a cord by which a weight is
+suspended, or by firing a mass of explosive material. The British
+measure of energy is the foot-pound; the metric measure is the
+kilogrammetre.
+
+Energy, whether kinetic or potential, may be observable and due to
+mass-motion; or it may be invisible and due to molecular movements.
+The energy of a heavenly body or of a cannon-shot, and that of heat or
+of electrical action, are illustrations of the two classes. In Nature
+we find utilizable potential energy in fuel, in food, in any available
+head of water, and in available chemical affinities. We find kinetic
+energy in the motion of the winds and the flow of running water, in
+the heat-motion of the sun's rays, in heat-currents on the earth, and
+in many intermittent movements of bodies acted on by applied forces,
+natural or artificial. The potential energy of fuel and of food has
+already been seen to have been derived, at an earlier period, from the
+kinetic energy of the sun's rays, the fuel or the food being thus made
+a storehouse or reservoir of energy. It is also seen that the animal
+system is simply a "mechanism of transmission" for energy, and does
+not create but simply diverts it to any desired direction of
+application.
+
+All the available forms of energy can be readily traced back to a
+common origin in the potential energy of a universe of nebulous
+substance (chaos), consisting of infinitely diffused matter of
+immeasurably slight density, whose "energy of position" had been,
+since the creation, gradually going through a process of
+transformation into the several forms of kinetic and potential energy
+above specified, through intermediate methods of action which are
+usually still in operation, such as the potential energy of chemical
+affinity, and the kinetic forms of energy seen in solar radiation, the
+rotation of the earth, and the heat of its interior.
+
+The _measure_ of any given quantity of energy, whatever may be its
+form, is the product of the resistance which it is capable of
+overcoming into the space through which it can move against that
+resistance, i. e., by the product RS. Or it is measured by the
+equivalent expressions (MV^{2})/2, or WV^{2}/2_g_, in which W is
+the weight, M is the "mass" of matter in motion, V the velocity, and
+_g_ the dynamic measure of the force of gravity, 32-1/6 feet, or 9.8
+metres, per second.
+
+There are three great laws of energetics:
+
+1. The sum total of the energy of the universe is invariable.
+
+2. The several forms of energy are interconvertible, and possess an
+exact quantitative equivalence.
+
+3. The tendency of all forms of kinetic energy is continually toward
+reduction to forms of molecular motion, and to their final dissipation
+uniformly throughout space.
+
+The history of the first two of these laws has already been traced.
+The latter was first enunciated by Prof. Sir William Thomson in 1853.
+Undissipated energy is called "Entrophy."
+
+The science of thermo-dynamics is, as has been stated, a branch of the
+science of energetics, and is the only branch of that science in the
+domain of the physicist which has been very much studied. This branch
+of science, which is restricted to the consideration of the relations
+of heat-energy to mechanical energy, is based upon the great fact
+determined by Rumford and Joule, and considers the behavior of those
+fluids which are used in heat-engines as the media through which
+energy is transferred from the one form to the other. As now accepted,
+it assumes the correctness of the hypothesis of the dynamic theory of
+fluids, which supposes their expansive force to be due to the motion
+of their molecules.
+
+This idea is as old as Lucretius, and was distinctly expressed by
+Bernouilli, Le Sage and Prevost, and Herapath. Joule recalled
+attention to this idea, in 1848, as explaining the pressure of gases
+by the impact of their molecules upon the sides of the containing
+vessels. Helmholtz, ten years later, beautifully developed the
+mathematics of media composed of moving, frictionless particles, and
+Clausius has carried on the work still further.
+
+The general conception of a gas, as held to-day, including the
+vortex-atom theory of Thomson and Rankine, supposes all bodies to
+consist of small particles called molecules, each of which is a
+chemical aggregation of its ultimate parts or atoms. These molecules
+are in a state of continual agitation, which is known as heat-motion.
+The higher the temperature, the more violent this agitation; the total
+quantity of motion is measured as _vis viva_ by the half-product of
+the mass into the square of the velocity of molecular movement, or in
+heat-units by the same product divided by Joule's equivalent. In
+solids, the range of motion is circumscribed, and change of form
+cannot take place. In fluids, the motion of the molecules has become
+sufficiently violent to enable them to break out of this range, and
+their motion is then no longer definitely restricted.
+
+The laws of thermo-dynamics are, according to Rankine:
+
+1. Heat-energy and mechanical energy are mutually convertible, one
+British thermal unit being the equivalent in heat-energy of 772
+foot-pounds of mechanical energy, and one metric _calorie_ equal to
+423.55 kilogrammetres of work.
+
+2. The energy due to the heat of each of the several equal parts into
+which a uniformly hot substance may be divided is the same; and the
+total heat-energy of the mass is equal to the sum of the energies of
+its parts.[113]
+
+  [113] This uniformity is not seen where a substance is changing its
+  physical state while developing its heat-energy, as occurs with
+  steam doing work while expanding.
+
+It follows that the work performed by the transformation of the energy
+of heat, during any indefinitely small variation of the state of a
+substance as respects temperature, is measured by the product of the
+absolute temperature into the variation of a "function," which
+function is the rate of variation of the work so done with
+temperature. This function is the quantity called by Rankine the
+"heat-potential" of the substance for the given kind of work. A
+similar function, which comprehends the total heat-variation,
+including both heat transformed and heat needed to effect accompanying
+physical changes, is called the "thermo-dynamic function." Rankine's
+expression for the general equation of thermo-dynamics includes the
+latter, and is given by him as follows:
+
+  J_dh_ = _d_H = _kd_[tau] + [tau]_d_F = [tau]_d_[phi],
+
+in which J is Joule's equivalent, _dh_ the variation of total heat in
+the substance, _kd_[tau] the product of the "dynamic specific heat"
+into the variation of temperature, or the total heat demanded to
+produce other changes than a transformation of energy, and [tau]_d_F
+is the work done by the transformation of heat-energy, or the product
+of the absolute temperature, [tau], into the differential of the
+heat-potential. [phi] is the thermo-dynamic function, and
+[tau]_d_[phi] measures the whole heat needed to produce,
+simultaneously, a certain amount of work or of mechanical energy, and,
+at the same time, to change the temperature of the working substance.
+
+Studying the behavior of gases and vapors, it is found that the work
+done when they are used, like steam, in heat-engines, consists of
+three parts:
+
+(_a._) The change effected in the total actual heat-motion of the
+fluid.
+
+(_b._) That heat which is expended in the production of internal work.
+
+(_c._) That heat which is expended in doing the external work of
+expansion.
+
+In any case in which the total heat expended exceeds that due the
+production of work on external bodies, the excess so supplied is so
+much added to the intrinsic energy of the substance absorbing it.
+
+The application of these laws to the working of steam in the engine is
+a comparatively recent step in the philosophy of the steam-engine, and
+we are indebted to Rankine for the first, and as yet only, extended
+and in any respect complete treatise embodying these now accepted
+principles.
+
+It was fifteen years after the publication of the first logical theory
+of the steam-engine, by Pambour,[114] before Rankine, in 1859, issued
+the most valuable of all his works, "The Steam-Engine and other Prime
+Movers." The work is far too abstruse for the general reader, and is
+even difficult reading for many accomplished engineers. It is
+excellent beyond praise, however, as a treatise on the thermo-dynamics
+of heat-engines. It will be for his successors the work of years to
+extend the application of the laws which he has worked out, and to
+place the results of his labors before students in a readily
+comprehended form.
+
+  [114] "Theorie de la Machine a Vapeur," par le Chevalier F. M. G. de
+  Pambour, Paris, 1844.
+
+William J. Macquorn Rankine, the Scotch engineer and philosopher, will
+always be remembered as the author of the modern philosophy of the
+steam-engine, and as the greatest among the founders of the science of
+thermo-dynamics. His death, while still occupying the chair of
+engineering at the University of Glasgow, December 24, 1872, at the
+early age of fifty-two, was one of the greatest losses to science and
+to the profession which have occurred during the century.
+
+
+
+
+CHAPTER VIII.
+
+_THE PHILOSOPHY OF THE STEAM-ENGINE._
+
+ITS APPLICATION; ITS TEACHINGS RESPECTING THE CONSTRUCTION OF THE
+ENGINE AND ITS IMPROVEMENT.
+
+  "Oftentimes an Uncertaintie hindered our going on so merrily, but by
+  persevering the Difficultie was mastered, and the new Triumph gave
+  stronger Heart unto us."--RALEIGH.
+
+  "If everything which we cannot comprehend is to be called an
+  impossibility, how many are daily presented to our eyes! and in
+  contemning as false that which we consider to be impossible, may we
+  not be depreciating a giant's effort to give an importance to our
+  own weakness?"--MONTAIGNE.
+
+  "They who aim vigorously at perfection will come nearer to it than
+  those whose laziness or despondency makes them give up its pursuit
+  from the feeling of its being unattainable."--CHESTERFIELD.
+
+
+As has been already stated, the steam-engine is a machine which is
+especially designed to transform energy, originally dormant or
+potential, into active and usefully available kinetic energy.
+
+When, millions of years ago, in that early period which the geologists
+call the carboniferous, the kinetic energy of the sun's rays, and of
+the glowing interior of the earth, was expended in the decomposition
+of the vast volumes of carbonic acid with which air was then charged,
+and in the production of a life-sustaining atmosphere and of the
+immense forests which then covered the earth with their almost
+inconceivably luxuriant vegetation, there was stored up for the
+benefit of the human race, then uncreated, an inconceivably great
+treasure of potential energy, which we are now just beginning to
+utilize. This potential energy becomes kinetic and available wherever
+and whenever the powerful chemical affinity of oxygen for carbon is
+permitted to come into play; and the fossil fuel stored in our
+coal-beds or the wood of existing forests is, by the familiar process
+of combustion, permitted to return to the state of combination with
+oxygen in which it existed in the earliest geological periods.
+
+The philosophy of the steam-engine, therefore, traces the changes
+which occur from this first step, by which, in the furnace of the
+steam-boiler, this potential energy which exists in the tendency of
+carbon and oxygen to combine to form carbonic acid is taken advantage
+of, and the utilizable kinetic energy of heat is produced in
+equivalent amount, to the final application of resulting mechanical
+energy to machinery of transmission, through which it is usefully
+applied to the elevation of water, to the driving of mills and
+machinery of all kinds, or to the hauling of "lightning" trains on our
+railways, or to the propulsion of the Great Eastern.
+
+The kinetic heat-energy developed in the furnace of the steam-boiler
+is partly transmitted through the metallic walls which inclose the
+steam and water within the boiler, there to evaporate water, and to
+assume that form of energy which exists in steam confined under
+pressure, and is partly carried away into the atmosphere in the
+discharged gaseous products of combustion, serving, however, a useful
+purpose, _en route_, by producing the draught needed to keep up
+combustion.
+
+The steam, with its store of heat-energy, passes through tortuous
+pipes and passages to the steam-cylinder of the engine, losing more or
+less heat on the way, and there expands, driving the piston before it,
+and losing heat by the transformation of that form of energy while
+doing mechanical work of equivalent amount. But this steam-cylinder is
+made of metal, a material which is one of the best conductors of heat,
+and therefore one of the very worst possible substances with which to
+inclose anything as subtile and difficult of control as the heat
+pervading a condensible vapor like steam. The process of internal
+condensation and reevaporation, which is the great enemy of economical
+working, thus has full play, and is only partly checked by the heat
+from the steam-jacket, which, penetrating the cylinder, assists by
+keeping up the temperature of the internal surface and checking the
+first step, condensation, which is an essential preliminary to the
+final waste by reevaporation. The piston, too, is of metal, and
+affords a most excellent way of exit for the heat escaping to the
+exhaust side.
+
+Finally, all unutilized heat rejected from the steam-cylinder is
+carried away from the machine, either by the water of condensation,
+or, in the non-condensing engine, by the atmosphere into which it is
+discharged.
+
+Having traced the method of operation of the steam-engine, it is easy
+to discover what principles are comprehended in its philosophy, to
+learn what are known facts bearing upon its operation, and to
+determine what are the directions in which improvement must take
+place, what are the limits beyond which improvement cannot possibly be
+carried, and, in some directions, to determine what is the proper
+course to pursue in effecting improvements. The general direction of
+change in the past, as well as at present, is easily seen, and it may
+usually be assumed that there will be no immediate change of direction
+in a course which has long been preserved, and which is well defined.
+We may, therefore, form an idea of the probable direction in which to
+look for improvement in the near future.
+
+Reviewing the operations which go on in this machine during the
+process of transformation of energy which has been outlined, and
+studying it more in detail, we may deduce the principles which govern
+its design and construction, guide us in its management, and determine
+its efficiency.
+
+In the furnace of the boiler, the quantity of heat developed in
+available form is proportional to the amount of fuel burned. It is
+available in proportion to the temperature attained by the products of
+combustion; were this temperature no higher than that of the boiler,
+the heat would all pass off unutilized. But the temperature produced
+by a given quantity of heat, measured in heat-units, is greater as the
+volume of gas heated is less. It follows that, at this point,
+therefore, the fuel should be perfectly consumed with the least
+possible air-supply, and the least possible abstraction of heat before
+combustion is complete. High temperature of furnace, also, favors
+complete combustion. We hence conclude that, in the steam-boiler
+furnace, fuel should be burned completely in a chamber having
+non-conducting walls, and with the smallest air-supply compatible with
+thorough combustion; and, further, that the air should be free from
+moisture, that greatest of all absorbents of heat, and that the
+products of combustion should be removed from the furnace before
+beginning to drain their heat into the boiler. A fire-brick furnace, a
+large combustion-chamber with thorough intermixture of gases within
+it, good fuel, and a restricted and carefully-distributed supply of
+air, seem to be the conditions which meet these requisites best.
+
+The heat generated by combustion traverses the walls which separate
+the gases of the furnace from the steam and water confined within the
+boiler, and is then taken up by those fluids, raising their
+temperature from that of the entering "feed-water" to that due the
+steam-pressure, and expanding the liquid into steam occupying a
+greatly-increased volume, thus doing a certain amount of work, besides
+increasing temperature. The extent to which heat may thus be usefully
+withdrawn from the furnace-gases depends upon the conductivity of the
+metallic wall, the rate at which the water will take heat from the
+metal, and the difference of temperature on the two sides of the
+metal. Extended "heating-surface," therefore, a metal of high
+conducting power, and a maximum difference of temperature on the two
+sides of the separating wall of metal, are the essential conditions of
+economy here. The heating-surface is sometimes made of so great an
+area that the temperature of the escaping gases is too low to give
+good chimney-draught, and a "mechanical draught" is resorted to,
+revolving "fan-blowers" being ordinarily used for its production. It
+is most economical to adopt this method. The steam-boiler is generally
+constructed of iron--sometimes, but rarely, of cast-iron, although
+"steel," where not hard enough to harden or temper, is better in
+consequence of its greater strength and homogeneousness of structure,
+and its better conductivity. The maximum conductivity of flow of heat
+for any given material is secured by so designing the boiler as to
+secure rapid, steady, and complete circulation of the water within it.
+The maximum rapidity of transfer throughout the whole area of
+heating-surface is secured, usually, by taking the feed-water into the
+boiler as nearly as possible at the point where the gases are
+discharged into the chimney-flue, withdrawing the steam nearer the
+point of maximum temperature of flues, and securing opposite
+directions of flow for the gases on the one side and the water on the
+other. Losses of heat from the boiler, by conduction and radiation to
+surrounding bodies, are checked as far as possible by non-conducting
+coverings.
+
+The mechanical equivalent of the heat generated in the boiler is
+easily calculated when the conditions of working are known. A pound of
+pure carbon has been found to be capable of liberating by its perfect
+combustion, resulting in the formation of carbonic acid, 14,500
+British thermal units, equivalent to 14,500 x 772 = 11,194,000
+foot-pounds of work, and, if burned in one hour, to 11194000/1980000 =
+5.6 horse-power. In other words, with perfect utilization, but 10/56 =
+0.177, or about one-sixth, of a pound of carbon would be needed per
+hour for each horse-power of work done. But even good coal is not
+nearly all carbon, and has but about nine-tenths this heat-producing
+power, and it is usually rated as yielding about 10,000,000
+foot-pounds of work per pound. The evaporative power of pure carbon
+being rated at 15 pounds of water, that of good coal may be stated at
+13-1/2. In metric measures, one gramme of good coal should evaporate
+about 13-1/2 grammes of water from the boiling-point, producing the
+equivalent of about 3,000,000 kilogrammetres of work from the 7,272
+_calories_ of heat thus generated. A gramme of pure carbon generates
+in its combustion 8,080 _calories_ of heat. Per hour and per
+horse-power, 0.08, or less than one-twelfth, of a kilogram of carbon
+burned per hour evolves heat-energy equal to one horse-power.
+
+Of the coal burned in a steam-boiler, it rarely happens that more than
+three-fourths is utilized in making steam; 7,500,000 foot-pounds
+(1,036,898 kilogrammetres) is, therefore, as much energy as is usually
+sent to the engine per pound of good coal burned in the steam-boiler.
+The "efficiency" of a good steam-boiler is therefore usually not far
+from 0.75 as a maximum. Rankine estimates this quantity for ordinary
+boilers of good design and with chimney-draught at
+
+          0.92
+  E = ------------;
+      1 + 0.5(F/S)
+
+in which F/S is the ratio of weight of fuel burned per square foot of
+grate to the ratio of heating to grate surface; this is a formula of
+fairly close approximation for general practice.
+
+The steam in the engine first drives the piston some distance before
+the induction or steam valve is closed, and it then expands, doing
+work, and condensing in proportion to work done as the expansion
+proceeds, until it is finally released by the opening of the exhaust
+or eduction valve. Saturated steam is modified in its action by a
+process which has already been described, condensing at the beginning
+and reevaporating at the end of the stroke, thus carrying into the
+condenser considerable quantities of heat which should have been
+utilized in the development of power. Whether this operation takes
+place in one cylinder or in several is only of importance in so far as
+it modifies the losses due to conduction and radiation of heat, to
+condensation and reevaporation of steam, and to the friction of the
+machine. It has already been seen how these losses are modified by the
+substitution of the compound for the single-cylinder engine.
+
+The laws of thermo-dynamics teach, as has been stated, that the
+proportion of the heat-energy contained in the steam or other working
+fluid which may be transformed into mechanical energy is a fraction
+(H_{1} - H_{2})/H_{1}, of the total, in which H_{1} and H_{2} are the
+quantities of heat contained in the steam at the beginning and at the
+end of its operation, measuring from the absolute zero of heat-motion.
+In perfect gases,
+
+  H_{1} - H_{2}   [tau]_{1} - [tau]_{2}      T_{1} - T_{2}
+  ------------- = --------------------- = --------------------
+      H_{1}             [tau]_{1}         T_{1} + 461.2 deg. Fahr.
+
+but in imperfect gases, and especially in vapors which, like steam,
+condense, or otherwise change their physical state, this equality may
+still exist,
+
+  (H_{1} - H_{2})/H_{1} = ([tau]_{1} - [tau]_{2})/[tau]_{1};
+
+and the fluid is equally efficient with the
+perfect gas as a working substance in a heat-engine. In any case it is
+seen that the efficiency is greatest when the whole of the heat is
+received at the maximum and rejected at the minimum attainable
+temperatures.
+
+Assuming this expression strictly accurate, a hot-air engine working
+from 413.6 deg. Fahr, or 874.8 deg. absolute temperature, down to 122 deg. Fahr,
+or 583.2 deg. absolute, should have an efficiency of 0.263, transforming
+that proportion of available heat into mechanical work. The engines
+of the steamer Ericsson closely approached this figure, and gave a
+horse-power for each 1.87 pound of coal burned per hour.
+
+Steam expands in the steam-cylinder quite differently under different
+circumstances. If no heat is either communicated to it or abstracted
+from it, however, it expands in an hyperbolic curve, losing its
+tension much more rapidly than when expanded without doing work, in
+consequence both of its change of volume and its condensation. The
+algebraic expression for this method of expansion is, according to
+Rankine, PV^{1.111} = C, a constant, or, according to other
+authorities, from PV^{1.135} = C to PV^{1.140} = C. The greater the
+value of the exponent of V, the greater the efficiency of the fluid
+between any two temperatures. The maximum value has been found to be
+given where the steam is saturated, but perfectly dry, at the
+commencement of its expansion. The loss due to condensation on the
+cooled interior surface of the cylinder at the commencement of the
+stroke and the subsequent reevaporation as expansion progresses is
+least when the cylinder is kept hot by its steam-jacket and when least
+time is given during the stroke for this transfer of heat between the
+metal and the vapor.
+
+It may be said that, all things considered, therefore, losses of heat
+in the steam-cylinder are least when the steam enters dry, or
+moderately superheated, where the interior surfaces are kept hottest
+by the steam-jacket or by the hot-air jacket sometimes used, and where
+piston-speed and velocity of rotation are highest.[115] The best of
+compound engines, using steam of seventy-five pounds pressure and
+condensing, usually require about two pounds of coal per
+hour--20,000,000 foot-pounds of energy at the furnace--to develop a
+horse-power, i. e., about ten times the heat-equivalent of the
+mechanical work which they accomplish. Were the steam to expand like
+the permanent gases, they would have a theoretical efficiency of about
+one-quarter; actually, the efficiency is only one-tenth. The
+steam-engine, therefore, utilizes about two-fifths the heat-energy
+theoretically available with the best type of engine in general use.
+By far the greater part, nearly all, in fact, of the nine-tenths
+wasted is rejected in the exhaust steam, and can only be saved by some
+such method as is hereafter to be suggested of retaining that heat and
+returning it to the boiler.
+
+  [115] In some cases, as in the Allen engine, the speed of piston has
+  become very high, approaching 800((stroke)^{1/3}).
+
+The mechanical power which has now been communicated to the mechanism
+of the engine by the transfer of the kinetic energy of the hot steam
+to the piston is finally usefully applied to whatever "mechanism of
+transmission" forms the connection with the machinery driven by the
+engine. In this transfer, there is some loss in the engine itself, by
+friction. This is an extremely variable amount, and it can be made
+very small by skillful design and good workmanship and management. It
+may be taken at one-half pound per square inch of piston for good
+engines of 100 horse-power and upward, but is often several pounds in
+very small engines. It is least when the rubbing surfaces are of
+different materials, but both of smooth, hard, close-grained metal,
+well lubricated, and where advantage is taken of any arrangement of
+parts which permits the equilibration of pressure, as on the
+shaft-bearings of double and triple engines. The friction of a
+steam-engine of large size and good design is usually between five and
+seven per cent. of its total power. It increases rapidly as the size
+of engine decreases.
+
+Having now traced somewhat minutely the growth of the steam-engine
+from the beginning of the Christian era to the present time, having
+rapidly outlined the equally gradual, though intermittent, growth of
+its philosophy, and having shown how the principles of science find
+application in the operation of this wonderful machine, we are now
+prepared to study the conditions which control the intelligent
+designer, and to endeavor to learn what are the lessons taught us by
+science and by experience in regard to the essential requisites of
+efficient working of steam and economy in the consumption of fuel. We
+may even venture to point out definitely the direction in which
+improvement is now progressing as indicated by a study of these
+requisites, and may be able to perceive the natural limits to such
+progress, and possibly to conjecture what must be the character of
+that change of type which only can take the engineer beyond the limit
+set to his advance so long as he is confined to the construction of
+the present type of engine.
+
+First, we must consider the question: _What is the problem, stated
+precisely and in its most general form, that engineers have been here
+attempting to solve?_
+
+After stating the problem, we will examine the record with a view to
+determine what direction the path of improvement has taken hitherto,
+to learn what are the conditions of efficiency which should govern the
+construction of the modern steam-engine, and, so far as we may judge
+the future by the past, by inference, to ascertain what appears to be
+the proper course for the present and for the immediate future. Still
+further, we will inquire, what are the conditions, physical and
+intellectual, which best aid our progress in perfecting the
+steam-engine.
+
+This most important problem may be stated in its most general, yet
+definite, form as follows:
+
+_To construct a machine which shall, in the most perfect manner
+possible, convert the kinetic energy of heat into mechanical power,
+the heat being derived from the combustion of fuel, and steam being
+the receiver and the conveyer of that heat._
+
+The problem, as we have already seen, embodies two distinct and
+equally important inquiries:
+
+The first: What are the scientific principles involved in the problem
+as stated?
+
+The second: How shall a machine be constructed that shall most
+efficiently embody, and accord with, not only those scientific
+principles, but also all of those principles of engineering practice
+that so vitally affect the economical value of every machine?
+
+The one question is addressed to the man of science, the other to the
+engineer. They can be satisfactorily answered, even so far as our
+knowledge at present permits, after studying with care the scientific
+principles involved in the theory of the steam-engine under the best
+light that science can afford us, and by a careful study of the
+various steps of improvement that have taken place and of accompanying
+variations of structure, analyzing the effect of each change, and
+tracing the reasons for them.
+
+The theory of the steam-engine is too important and too extensive a
+subject to be satisfactorily treated here in even the most concise
+possible manner. I can only attempt a plain statement of the course
+which seems to be pointed out by science as the proper one to pursue
+in the endeavor to increase the economical efficiency of
+steam-engines.
+
+The teachings of science indicate that _success in economically
+deriving mechanical power from the energy of heat-motion will, in all
+cases, be the greater as we work between more widely separated limits
+of temperature, and as we more perfectly provide against losses by
+dissipation of heat in directions in which it is unavailable for the
+production of power_.
+
+Scientific research, as we have seen, has proved that, in all known
+varieties of heat-engine, a large loss of effect is unavoidable from
+the fact that we cannot, in the ordinary steam-engine, reduce the
+lower limit of temperature, in working, below a point which is far
+above the absolute zero of temperature--far above that point at which
+bodies have no heat-motion. The point corresponding to the mean
+temperature of the surface of the earth is above the ordinary lower
+limit.
+
+The higher the temperature of the steam when it enters the steam
+cylinder, and the lower that which it reaches before the exhaust
+occurs, the greater, science tells us, will be our success, provided
+we at the same time avoid waste of heat and power.
+
+Now, looking back over the history of the steam-engine, we may briefly
+note the prominent improvements and the most striking changes of form,
+and may thus endeavor to obtain some idea of the general direction in
+which we are to look for further advance.
+
+Beginning with the machine of Porta, at which point we may first take
+up an unbroken thread, it will be remembered that we there found a
+single vessel performing the functions of all the parts of a modern
+pumping-engine; it was, at once, boiler, steam-cylinder, and
+condenser, as well as both a lifting and a forcing pump.
+
+The Marquis of Worcester divided the engine into two parts, using a
+separate boiler.
+
+Savery duplicated that part of the engine of Worcester which performed
+the several parts of pump, steam-cylinder, and condenser, and added
+the use of water to effect rapid condensation, perfecting, so far as
+it was ever perfected, the steam-engine as a simple machine.
+
+Newcomen and Calley next separated the pump from the steam-engine
+proper, producing the modern steam-engine--the engine as a train of
+mechanism; and in their engine, as in Savery's, we noticed the use of
+surface condensation first, and subsequently that of the jet thrown
+into the midst of the steam to be condensed.
+
+Watt finally effected the crowning improvements, and completed the
+movement oL "differentiation" by separating the condenser from the
+steam-cylinder. Here this process of change ceased, the several
+important operations of the steam-engine now being conducted each in a
+separate vessel. The boiler furnished the steam, the cylinder derived
+from it mechanical power, and it was finally condensed in a separate
+vessel, while the power which had been obtained from it in the
+steam-cylinder was transmitted through still other parts, to the
+pumps, or wherever work was to be done.
+
+Watt, also, took the initiative in another direction. He continually
+increased the efficiency of the machine by improving the proportions
+of its parts and the character of its workmanship, thus making it
+possible to render available many of those improvements in detail upon
+which effectiveness is so greatly dependent and which are only useful
+when made by a skillful workman.
+
+Watt and his contemporaries also commenced that movement toward higher
+pressures of steam and greater expansion which has been the most
+striking feature noticed in the progress of steam-engineering since
+his time. Newcomen used steam of barely more than atmospheric pressure
+and raised 105,000 pounds of water one foot high with a pound of coal
+consumed. Smeaton raised the pressure somewhat and increased the duty
+considerably. Watt started with a duty double that of Newcomen and
+raised it to 320,000 foot-pounds per pound of coal, with steam at 10
+pounds pressure. To-day, Cornish engines of the same general plan as
+those of Watt, but worked with 40 to 60 pounds of steam and expanding
+three or four times, do a duty probably averaging, with the better
+class of engines, 600,000 foot-pounds per pound of coal. The compound
+pumping-engine runs the figure up to above 1,000,000.
+
+The increase in steam-pressure and in expansion since Watt's time has
+been accompanied by a very great improvement in workmanship--a
+consequence, very largely, of the rapid increase in perfection, and in
+the wide range of adaptation of machine-tools--by higher skill and
+intelligence in designing engines and boilers, by increased
+piston-speed, greater care in obtaining dry steam, and in keeping it
+dry until thrown out of the cylinder, either by steam-jacketing or by
+superheating, or both combined; it has further been accompanied by a
+greater attention to the important matter of providing carefully
+against losses by radiation and conduction of heat. We use, finally,
+the compound or double-cylinder engine for the purpose of saving some
+of the heat usually lost in internal condensation and reevaporation,
+and precipitation of condensed vapor from great expansion.
+
+It is evident that, although there is a limit, tolerably well defined,
+in the scale of temperature, below which we cannot expect to pass, a
+degree gained in approaching this lower limit is more remunerative
+than a degree gained in the range of temperature available by
+increasing temperatures.[116]
+
+  [116] The fact here referred to is easily seen if it is supposed
+  that an engine is supplied with steam at a temperature of 400 deg.
+  above absolute zero and works it, without waste, down to a
+  temperature of 200 deg.. Suppose one inventor to adapt the engine to the
+  use of steam of a range from 500 deg. down to 200 deg., while another works
+  his engine, with equally effective provision against losses, between
+  the limits of 400 deg. and 100 deg., an equal range with a lower mean. The
+  first case gives an efficiency of one-half, the second three-fifths,
+  and the third three-fourths, the last giving the highest effect.
+
+Hence the attempt made by the French inventor, Du Trembly, about the
+year 1850, and by other inventors since, to utilize a larger
+proportion of heat by approaching more closely the lower limit, was in
+accordance with known scientific principles.
+
+We may summarize the result of our examination of the growth of the
+steam-engine thus:
+
+_First._ The process of improvement has been one, primarily, of
+"differentiation;"[117] the number of parts has been continually
+increased; while the work of each part has been simplified, a separate
+organ being appropriated to each process in the cycle of operations.
+
+  [117] This term, though perhaps not familiar to engineers, expresses
+  the idea perfectly.
+
+_Secondly._ A kind of secondary process of differentiation has, to
+some extent, followed the completion of the primary one, in which
+secondary process one operation is conducted partly in one and partly
+in another portion of the machine. This is illustrated by the two
+cylinders of the compound engine and by the duplication noticed in the
+binary engine.
+
+_Thirdly._ The direction of improvement has been marked by a continual
+increase of steam-pressure, greater expansion, provision for obtaining
+dry steam, high piston-speed, careful protection against loss of heat
+by conduction or radiation, and, in marine engines, by surface
+condensation.
+
+The direction which improvement seems now to be taking, and the proper
+direction, as indicated by an examination of the principles of
+science, as well as by our review of the steps already taken, would
+seem to be: working between the widest attainable limits of
+temperature.
+
+Steam must enter the machine at the highest possible temperature, must
+be protected from waste, and must retain, at the moment before
+exhaust, the least possible amount of heat. He whose inventive genius,
+or mechanical skill, contributes to effect either the use of higher
+steam with safety and without waste, or the reduction of the
+temperature of discharge, confers a boon upon mankind.
+
+In detail: In the engine, the tendency is, and may probably be
+expected to continue, in the near future at least, toward higher
+steam-pressure, greater expansion in more than one cylinder,
+steam-jacketing, superheating, a careful use of non-conducting
+protectors against waste, and the adoption of still higher
+piston-speeds.
+
+In the boiler: more complete combustion without excess of air passing
+through the furnace, and more thorough absorption of heat from the
+furnace-gases. The latter will probably be ultimately effected by the
+use of a mechanically produced draught, in place of the far more
+wasteful method of obtaining it by the expenditure of heat in the
+chimney.
+
+In construction we may anticipate the use of better materials, and
+more careful workmanship, especially in the boiler, and much
+improvement in forms and proportions of details.
+
+In management, there is a wide field for improvement, which
+improvement we may feel assured will rapidly take place, as it has now
+become well understood that great care, skill, and intelligence are
+important essentials to the economical management of the steam-engine,
+and that they repay, liberally, all of the expense in time and money
+that is requisite to secure them.
+
+In attempting improvements in the directions indicated, it would be
+the height of folly to assume that we have reached a limit in any one
+of them, or even that we have approached a limit. If further progress
+seems checked by inadequate returns for efforts made, in any case, to
+advance beyond present practice, it becomes the duty of the engineer
+to detect the cause of such hinderance, and, having found it, to
+remove it.
+
+A few years ago, the movement toward the expansive working of high
+steam was checked by experiments seeming to prove positive
+disadvantage to follow advance beyond a certain point. A careful
+revision of results, however, showed that this was true only with
+engines built, as was then common, in utter disregard of all the
+principles involved in such a use of steam, and of the precautions
+necessary to be taken to insure the gain which science taught us
+should follow. The hinderances are mechanical, and it is for the
+engineer to remove them.
+
+The last remark is especially applicable to the work of the engineer
+who is attempting to advance in the direction in which, as already
+intimated, an unmistakable revolution is now progressing, the
+modification of the modern steam-engine to adapt it safely and
+successfully to run at the high piston-speed, and great velocity of
+rotation which have been already attained and which must undoubtedly
+be greatly exceeded in the future. As there is no known and definite
+limit to the economical increase of speed, and as the limit set by
+practical conditions is continually being set farther back as the
+builder acquires greater skill and attains greater accuracy of
+workmanship and the power to insure greater rigidity of parts and
+durability of wearing surfaces, we must anticipate a continued and
+indefinite progress in this direction--a progress which must evidently
+be of advantage, whatever may be the direction that other changes may
+take.
+
+It is evident that this adaptation of the steam-engine to great speed
+of piston is the work now to be done by the engineer. The requisites
+to success are obvious, and may be concisely stated as follows:
+
+1. Extreme accuracy in proportions.
+
+2. Perfect accuracy in fitting parts to each other.
+
+3. Absolute symmetry of journals.
+
+4. Ample area and maximum durability of rubbing surfaces.
+
+5. Perfect certainty of an ample and continuous lubrication.
+
+6. A nicely calculated and adjusted balance of reciprocating parts.
+
+7. Security against injury by shock, whether due to the presence of
+water in the cylinder or to looseness of running parts.
+
+8. A "positive-motion" cut-off gear.
+
+9. A powerful but sensitive and accurately-working governor
+determining the degree of expansion.[118]
+
+  [118] The author is not absolutely confident on the latter point. It
+  may be found more economical and satisfactory, ultimately, to
+  determine the point of cut-off by an automatic apparatus adjusting
+  the expansion-gear _by reference to the steam-pressure_, regulating
+  the speed by attaching the governor elsewhere. The author has
+  devised several forms of apparatus of the kind referred to.
+
+10. Well-balanced valves and an easy-working valve-gear.
+
+11. Small volume of "dead-space," or "clearance," and properly
+adjusted "compression."
+
+It would seem sufficiently evident that the engine with detachable
+("drop") cut-off valve-gear must, sooner or later, become an obsolete
+type, although the substitution of springs or of steam-pressure for
+gravity in the closing of the detached valve may defer greatly this
+apparently inevitable change. The "engine of the future" will not
+probably be a "drop cut-off engine."
+
+As regards the construction of the engine as a piece of mechanism, the
+principles and practice of good engineering are precisely the same,
+whether applied in the designing of the compound or of the ordinary
+type of steam-engine. The proportioning of the two machines to each
+other in such manner as to form an effective whole, by procuring
+approximately equal amounts of work from both, is the only essential
+peculiarity of compound-engine design which calls for especial care,
+and the method of securing success in practice may be stated to be,
+for both forms of engines, as follows:
+
+1. A good design, by which is meant--
+
+_a._ Correct proportions, both in general dimensions and in
+arrangement of parts, and proper forms and sizes of details to
+withstand safely the forces which may be expected to come upon them.
+
+_b._ A general plan which embodies the recognized practice of good
+engineering.
+
+_c._ Adaptation to the specific work which it is intended to perform,
+in size and in efficiency. It sometimes happens that good practice
+dictates the use of a comparatively uneconomical design.
+
+2. Good construction, by which is meant--
+
+_a._ The use of good material.
+
+_b._ Accurate workmanship.
+
+_c._ Skillful fitting and a proper "assemblage" of parts.
+
+3. Proper connection with its work, that it may do that work under the
+conditions assumed in its design.
+
+4. Skillful management by those in whose hands it is placed.
+
+_In general_, it may be stated that, to secure maximum economical
+efficiency, steam should be worked at as high a pressure as possible,
+and the expansion should be fixed as nearly as possible at the point
+of maximum economy for that pressure. In general, the number of times
+which the volume of steam may be expanded in the standard
+single-cylinder, high-pressure engine with maximum economy, is not far
+from 1/2 sqrt(P), where P is the pressure in pounds per square inch;
+it rarely exceeds 0.75 sqrt(P). This may be exceeded in
+double-cylinder engines. It is even more disadvantageous to cut off
+too short than to "'follow' too far." With considerable expansion,
+steam-jacketing and moderate superheating should be adopted, to
+prevent excessive losses by internal condensation and reevaporation;
+and expansion should take place in double cylinders, to avoid
+excessive weight of parts, irregularity of motion, and great loss by
+friction.
+
+To secure this vitally important economy, it is advisable to seek some
+practicable method of lining the cylinder with a non-conducting
+material. This plan, as has been seen, was adopted by Smeaton, in
+constructing Newcomen engines a century ago. Smeaton used wood on his
+pistons, and Watt tried wood as a material for steam-cylinder linings.
+That material is too perishable at temperatures now common, and no
+metal has yet been substituted, or even discovered, which answers the
+same purpose. The loss will also be reduced by increasing the speed of
+rotation and velocity of piston. Where no effectual means can be found
+of preventing contact of the steam with a good absorbent and conductor
+of heat, it will be found best to sacrifice some of the efficiency due
+to the change of state of the vapor, by superheating it and sending it
+into the cylinder at a temperature considerably exceeding that of
+saturation. With low steam and slowly-moving pistons, it is better to
+pursue the latter course than to attempt to increase the efficiency of
+the engine by greater expansion.
+
+External surfaces should be carefully covered by non-conductors and
+non-radiators, to prevent losses by conduction and radiation of heat.
+It is especially necessary to reduce back-pressure and to obtain the
+most perfect vacuum possible without overloading the air-pump, if it
+is desired to obtain the maximum efficiency by expansion, and it then
+becomes also very necessary to reduce losses by "dead-spaces" and by
+badly-adjusted valves.
+
+The piston-speed should be as great as can be sustained with safety.
+
+Good engines should not require more than W = (200/sqrt(P)) where W =
+the weight of steam per hour and per horse-power; the best practice
+gives about W = (180/sqrt(P)) in large engines with dry steam, high
+piston-speed, and good design, construction, and management.
+
+The expansion-valve gear should be simple. The point of cut-off is
+perhaps best determined by the governor. The valve should close
+rapidly, but without shock, and should be balanced, or some other
+device should be adopted to make it easy to move and free from
+liability to cutting or rapid wear.
+
+The governor should act promptly and powerfully, and should be free
+from liability to oscillate, and to thus introduce irregularities
+which are sometimes not less serious than those which the instrument
+is intended to prevent.
+
+Friction should be reduced as much as possible, and careful provision
+should be made to economize lubricants as well as fuel.
+
+The Principles of Steam-Boiler Construction are exceedingly simple;
+and although attempts are almost daily made to obtain improved
+results by varying the design and arrangement of heating-surface, the
+best boilers of nearly all makers of acknowledged standing are
+practically equal in merit, although of very diverse forms.
+
+In making boilers, the effort of the engineer should evidently be:
+
+1. To secure complete combustion of the fuel without permitting
+dilution of the products of combustion by excess of air.
+
+2. To secure as high temperature of furnace as possible.
+
+3. To so arrange heating-surfaces that, without checking draught, the
+available heat shall be most completely taken up and utilized.
+
+4. To make the form of boiler such that it shall be constructed
+without mechanical difficulty or excessive expense.
+
+5. To give it such form that it shall be durable, under the action of
+the hot gases and of the corroding elements of the atmosphere.
+
+6. To make every part accessible for cleaning and repairs.
+
+7. To make every part as nearly as possible uniform in strength, and
+in liability to loss of strength by wear and tear, so that the boiler
+when old shall not be rendered useless by local defects.
+
+8. To adopt a reasonably high "factor of safety" in proportioning
+parts.
+
+9. To provide efficient safety-valves, steam-gauges, and other
+appurtenances.
+
+10. To secure intelligent and very careful management.
+
+In securing complete combustion, the first of these desiderata, an
+ample supply of air and its thorough intermixture with the combustible
+elements of the fuel are essential; for the second--high temperature
+of furnace--it is necessary that the air-supply shall not be in excess
+of that absolutely needed to give complete combustion. The efficiency
+of a furnace in making heat available is measured by
+
+       T - T'
+  E = -------;
+      T - _t_
+
+in which E represents the ratio of heat utilized to the whole
+calorific value of the fuel, T is the furnace-temperature, T' the
+temperature of the chimney, and _t_ that of the external air. The
+higher the furnace-temperature and the lower that of the chimney, the
+greater the proportion of heat available. It is further evident that,
+however perfect the combustion, no heat can be utilized if either the
+temperature of the chimney approximates to that of the furnace, or if
+the temperature of the furnace is reduced by dilution approximately to
+that of the boiler. Concentration of heat in the furnace is secured,
+in some cases, by special expedients, as by heating the entering air,
+or as in the Siemens gas-furnace, heating both the combustible gases
+and the supporter of combustion. Detached fire-brick furnaces have an
+advantage over the "fire-boxes" of steam-boilers in their higher
+temperature; surrounding the fire with non-conducting and highly
+heated surfaces is an effective method of securing high
+furnace-temperature.
+
+In arranging heating-surface, the effort should be to impede the
+draught as little as possible, and so to place them that the
+circulation of water within the boiler should be free and rapid at
+every part reached by the hot gases. The directions of circulation of
+water on the one side and of gas on the other side of the sheet
+should, whenever possible, be opposite. The cold water should enter
+where the cooled gases leave, and the steam should be taken off
+farthest from that point. The temperature of chimney-gases has thus
+been reduced in practice to less than 300 deg. Fahr., and an efficiency
+equal to 0.75 to 0.80 the theoretical has been attained.
+
+The extent of heating-surface simply, in all of the best forms of
+boiler, determines the efficiency, and in them the disposition of that
+surface seldom affects it to any great extent. The area of
+heating-surface may also be varied within very wide limits without
+very greatly modifying efficiency. A ratio of 25 to 1 in flue and 30
+to 1 in tubular boilers represents the relative area of heating and
+grate surfaces as chosen in the practice of the best-known builders.
+
+The material of the boiler should be tough and ductile iron, or,
+better, a soft steel containing only sufficient carbon to insure
+melting in the crucible or on the hearth of the melting-furnace, and
+so little that no danger may exist of hardening and cracking under the
+action of sudden and great changes of temperature.
+
+Where iron is used, it is necessary to select a somewhat hard, but
+homogeneous and tough, quality for the fire-box sheets or any part
+exposed to flames.
+
+The factor of safety is invariably too low in this country, and is
+never too high in Europe. Foreign builders are more careful in this
+matter than our makers in the United States. The boiler should be
+built strong enough to bear a pressure at least six times the proposed
+working-pressure; as the boiler grows weak with age, it should be
+occasionally tested to a pressure far above the working-pressure,
+which latter should be reduced gradually to keep within the bounds of
+safety. In the United States, the factor of safety is seldom more than
+four in the new boilers, frequently much less, and even this is
+reduced practically to one and a third by the operation of our
+inspection-laws.
+
+The principles just enunciated are those generally, perhaps
+universally, accepted principles which are stated in all text-books of
+science and of steam-engineering, and are accepted by both engineers
+and men of science.
+
+These principles are correct, and the deductions which have been here
+formulated are rigidly exact, as applied to all types of heat-engine
+in use; and they lead us to the determination, in all cases, of the
+"modulus" of efficiency of the engine, i. e., to the calculation of
+the ratio of its actual efficiency to that efficiency which it would
+have, were it absolutely free from loss of heat by conduction or
+radiation, or other method of loss of heat or waste of power, by
+friction of parts or by shock.
+
+The best modern marine compound engines sometimes, as we have seen,
+consume as little as two pounds of coal per horse-power and per hour;
+but this is but about one-tenth the power derivable from the fuel,
+were all its heat thoroughly utilized. This loss may be divided thus:
+70 per cent. rejected in exhausted steam; 20 per cent. lost by
+conduction and radiation and by faults of mechanism and design; and
+only the 10 per cent. remaining is utilized. Thirty per cent. of the
+heat generated in the furnace is usually lost in the chimney, and of
+the remainder, which enters the engine, 20 per cent. at most is all
+which we can hope to save any portion of by improvements effected in
+our best existing type of steam-engine. It has already been shown how
+the engineer can best proceed in attempting this economy.
+
+The direction in which further improvement must take place in the
+standard type of engine is plainly that which shall most efficiently
+check losses by internal condensation and reevaporation by the
+transfer of heat to and from the metal of the steam-cylinder. The
+condensation of steam doing work is evidently not a disadvantage, but,
+on the contrary, a decided advantage.
+
+A new type of engine can, if at all, probably only supersede the
+common form when engineers can employ steam of very high pressure, and
+adopt much greater range of expansion than is now usual. Great
+velocity of piston and high speed of rotation are also essential in
+the attempt to make any revolution in steam-engine construction a
+success.
+
+When a new form of steam-engine is likely to be introduced, if at all,
+can be scarcely even conjectured. It seems evident that its success is
+to be secured, if a revolution is ever to occur, by the adoption of
+high steam-pressures, of great piston speeds, by care and skill in
+design, by the use of exceptionally excellent materials of
+construction, by great perfection of workmanship, and by intelligence
+in its management.
+
+Experiment and experience will probably lead gradually to the general
+and safe employment of much higher steam-pressures and very greatly
+increased piston-speeds, and may ultimately reveal and remove all
+those difficulties which must invariably be expected to be met here,
+as in all other attempts to effect radical changes, however important
+they may be.
+
+[Illustration]
+
+
+       *       *       *       *       *
+
+
+
+
+_Scientific Publications._
+
+
+=THE HUMAN SPECIES.= By A. DE QUATREFAGES, Professor of Anthropology
+in the Museum of Natural History, Paris. 12mo, cloth, $2.00.
+
+  The work treats of the unity, origin, antiquity, and original
+  localization of the human species, peopling of the globe,
+  acclimatization, primitive man, formation of the human races, fossil
+  human races, present human races, and the physical and psychological
+  characters of mankind.
+
+
+=STUDENTS' TEXT-BOOK OF COLOR; or, MODERN CHROMATICS.= With
+Applications to Art and Industry. With 130 Original Illustrations, and
+Frontispiece in Colors. By OGDEN N. ROOD, Professor of Physics in
+Columbia College. 12mo, cloth, $2.00.
+
+  "In this interesting book Professor Rood, who, as a distinguished
+  Professor of Physics in Columbia College, United States, must be
+  accepted as a competent authority on the branch of science of which
+  he treats, deals briefly and succinctly with what may be termed the
+  scientific _rationale_ of his subject. But the chief value of his
+  work is to be attributed to the fact that he is himself an
+  accomplished artist as well as an authoritative expounder of
+  science."--_Edinburgh Review, October, 1879, in an article on "The
+  Philosophy of Color._"
+
+
+=EDUCATION AS A SCIENCE.= By ALEXANDER BAIN, LL. D. 12mo, cloth,
+$1.75.
+
+  "This work must be pronounced the most remarkable discussion of
+  educational problems which has been published in our day. We do not
+  hesitate to bespeak for it the widest circulation and the most
+  earnest attention. It should be in the hands of every school-teacher
+  and friend of education throughout the land."--_New York Sun._
+
+
+=A HISTORY OF THE GROWTH OF THE STEAM-ENGINE.= By ROBERT H. THURSTON,
+A. M., C. E., Professor of Mechanical Engineering in the Stevens
+Institute of Technology, Hoboken, N. J., etc. With 163 Illustrations,
+including 15 Portraits. 12mo, cloth, $2.50.
+
+  "Professor Thurston almost exhausts his subject; details of
+  mechanism are followed by interesting biographies of the more
+  important inventors. If, as is contended, the steam-engine is the
+  most important physical agent in civilizing the world, its history
+  is a desideratum, and the readers of the present work will agree
+  that it could have a no more amusing and intelligent historian than
+  our author."--_Boston Gazette._
+
+
+=STUDIES IN SPECTRUM ANALYSIS.= By J. NORMAN LOCKYER, F. R. S.,
+Correspondent of the Institute of France, etc. With 60 Illustrations.
+12mo, cloth, $2.50.
+
+  "The study of spectrum analysis is one fraught with a peculiar
+  fascination, and some of the author's experiments are exceedingly
+  picturesque in their results. They are so lucidly described, too,
+  that the reader keeps on, from page to page, never flagging in
+  interest in the matter before him, nor putting down the book until
+  the last page is reached."--_New York Evening Express._
+
+
+=GENERAL PHYSIOLOGY OF MUSCLES AND NERVES.= By Dr. I. ROSENTHAL,
+Professor of Physiology at the University of Erlangen. With
+seventy-five Woodcuts. ("International Scientific Series.") 12mo,
+cloth, $1.50.
+
+  "The attempt at a connected account of the general physiology of
+  muscles and nerves is, as far as I know, the first of its kind. The
+  general data for this branch of science have been gained only within
+  the past thirty years."--_Extract from Preface._
+
+
+=SIGHT=: An Exposition of the Principles of Monocular and Binocular
+Vision By JOSEPH LE CONTE, LL. D., author of "Elements of Geology";
+"Religion and Science"; and Professor of Geology and Natural History
+in the University of California. With numerous Illustrations. 12mo,
+cloth, $1.50.
+
+  "It is pleasant to find an American book which can rank with the
+  very best of foreign works on this subject. Professor Le Conte has
+  long been known as an original investigator in this department; all
+  that he gives us is treated with a master-hand."--_The Nation._
+
+
+=ANIMAL LIFE=, as affected by the Natural Conditions of Existence. By
+KARL SEMPER, Professor of the University of Wuerzburg. With 2 Maps and
+106 Woodcuts, and Index. 12mo, cloth, $2.00.
+
+  "This is in many respects one of the most interesting contributions
+  to zooelogical literature which has appeared for some
+  time."--_Nature._
+
+
+=THE ATOMIC THEORY.= By AD. WURTZ, Membre de l'Institut; Doyen
+Honoraire de la Faculte de Medecine; Professeur a la Faculte des
+Sciences de Paris. Translated by E. CLEMINSHAW, M. A., F. C. S., F. I.
+C., Assistant Master at Sherborne School. 12mo, cloth, $1.50.
+
+  "There was need for a book like this, which discusses the atomic
+  theory both in its historic evolution and in its present form. And
+  perhaps no man of this age could have been selected so able to
+  perform the task in a masterly way as the illustrious French
+  chemist, Adolph Wurtz. It is impossible to convey to the reader, in
+  a notice like this, any adequate idea of the scope, lucid
+  instructiveness, and scientific interest of Professor Wurtz's book.
+  The modern problems of chemistry, which are commonly so obscure from
+  imperfect exposition, are here made wonderfully clear and
+  attractive."--_The Popular Science Monthly._
+
+
+=THE CRAYFISH.= An Introduction to the Study of Zooelogy. By Professor
+T. H. HUXLEY, F. R. S. With 82 Illustrations. 12mo, cloth, $1.75.
+
+  "Whoever will follow these pages, crayfish in hand, and will try to
+  verify for himself the statements which they contain, will find
+  himself brought face to face, with all the great zooelogical
+  questions which excite so lively an interest at the present day."
+
+  "The reader of this valuable monograph will lay it down with a
+  feeling of wonder at the amount and variety of matter which has been
+  got out of so seemingly slight and unpretending a
+  subject."--_Saturday Review._
+
+
+=SUICIDE=: An Essay In Comparative Moral Statistics. By HENRY
+MORSELLI, Professor of Psychological Medicine in Royal University,
+Turin. 12mo, Cloth, $1.75.
+
+  "Suicide" is a scientific inquiry, on the basis of the statistical
+  method, into the laws of suicidal phenomena. Dealing with the
+  subject as a branch of social science, it considers the increase of
+  suicide in different countries, and the comparison of nations,
+  races, and periods in its manifestation. The influences of age, sex,
+  constitution, climate, season, occupation, religion, prevailing
+  ideas, the elements of character, and the tendencies of
+  civilization, are comprehensively analyzed in their bearing upon the
+  propensity to self-destruction. Professor Morselli is an eminent
+  European authority on this subject. It is accompanied by colored
+  maps illustrating pictorially the results of statistical inquiries.
+
+
+=VOLCANOES: What they Are and what they Teach.= By J. W. JUDD,
+Professor of Geology in the Royal School of Mines (London). With
+Ninety-six Illustrations. 12mo. Cloth, $2.00.
+
+  "In no field has modern research been more fruitful than in that of
+  which Professor Judd gives a popular account in the present volume.
+  The great lines of dynamical, geological, and meteorological inquiry
+  converge upon the grand problem of the interior constitution of the
+  earth, and the vast influence of subterranean agencies.... His book
+  is very far from being a mere dry description of volcanoes and their
+  eruptions; it is rather a presentation of the terrestrial facts and
+  laws with which volcanic phenomena are associated."--_Popular
+  Science Monthly._
+
+  "The volume before us is one of the pleasantest science manuals we
+  have read for some time."--_Athenaeum._
+
+  "Mr. Judd's summary is so full and so concise that it is almost
+  impossible to give a fair idea in a short review."--_Pall Mall
+  Gazette._
+
+
+=THE SUN.= By C. A. YOUNG, Ph. D., LL. D., Professor of Astronomy in
+the College of New Jersey. With numerous Illustrations. 12mo. Cloth,
+$2.00.
+
+  "Professor Young is an authority on 'The Sun,' and writes from
+  intimate knowledge. He has studied that great luminary all his life,
+  invented and improved instruments for observing it, gone to all
+  quarters of the world in search of the best places and opportunities
+  to watch it, and has contributed important discoveries that have
+  extended our knowledge of it.
+
+  "It would take a cyclopaedia to represent all that has been done
+  toward clearing up the solar mysteries. Professor Young has
+  summarized the information, and presented it in a form completely
+  available for general readers. There is no rhetoric in his book; he
+  trusts the grandeur of his theme to kindle interest and impress the
+  feelings. His statements are plain, direct, clear, and condensed,
+  though ample enough for his purpose, and the substance of what is
+  generally wanted will be found accurately given in his
+  pages."--_Popular Science Monthly._
+
+
+=ILLUSIONS: A Psychological Study.= By JAMES SULLY, author of
+"Sensation and Intuition," etc. 12mo. Cloth. $1.50.
+
+  This volume takes a wide survey of the field of error, embracing in
+  its view not only the illusions commonly regarded as of the nature
+  of mental aberrations or hallucinations, but also other illusions
+  arising from that capacity for error which belongs essentially to
+  rational human nature. The author has endeavored to keep to a
+  strictly scientific treatment--that is to say, the description and
+  classification of acknowledged errors, and the exposition of them by
+  a reference to their psychical and physical conditions.
+
+  "This is not a technical work, but one of wide popular interest, in
+  the principles and results of which every one is concerned. The
+  illusions of perception of the senses and of dreams are first
+  considered, and then the author passes to the illusions of
+  introspection, errors of insight, illusions of memory, and illusions
+  of belief. The work is a noteworthy contribution to the original
+  progress of thought, and may be relied upon as representing the
+  present state of knowledge on the important subject to which it is
+  devoted."--_Popular Science Monthly._
+
+
+=THE BRAIN AND ITS FUNCTIONS.= By J. LUYS, Physician to the Hospice de
+la Salpetriere. With Illustrations. 12mo. Cloth, $1.50.
+
+  "No living physiologist is better entitled to speak with authority
+  upon the structure and functions of the brain than Dr. Luys. His
+  studies on the anatomy of the nervous system are acknowledged to be
+  the fullest and most systematic ever undertaken. Dr. Luys supports
+  his conclusions not only by his own anatomical researches, but also
+  by many functional observations of various other physiologists,
+  including of course Professor Ferrier's now classical
+  experiments."--_St. James's Gazette._
+
+  "Dr. Luys, at the head of the great French Insane Asylum, is one of
+  the most eminent and successful investigators of cerebral science
+  now living; and he has given unquestionably the clearest and most
+  interesting brief account yet made of the structure and operations
+  of the brain. We have been fascinated by this volume more than by
+  any other treatise we have yet seen on the machinery of sensibility
+  and thought; and we have been instructed not only by much that is
+  new, but by many sagacious practical hints such as it is well for
+  everybody to understand."--_The Popular Science Monthly._
+
+
+=THE CONCEPTS AND THEORIES OF MODERN PHYSICS.= By J. B. STALLO. 12mo.
+Cloth, $1.75.
+
+  "Judge Stallo's work is an inquiry into the validity of those
+  mechanical conceptions of the universe which are now held as
+  fundamental in physical science. He takes up the leading modern
+  doctrines which are based upon this mechanical conception, such as
+  the atomic constitution of matter, the kinetic theory of gases, the
+  conservation of energy, the nebular hypothesis, and other views, to
+  find how much stands upon solid empirical ground, and how much rests
+  upon metaphysical speculation. Since the appearance of Dr. Draper's
+  'Religion and Science,' no book has been published in the country
+  calculated to make so deep an impression on thoughtful and educated
+  readers as this volume.... The range and minuteness of the author's
+  learning, the acuteness of his reasoning, and the singular precision
+  and clearness of his style, are qualities which very seldom have
+  been jointly exhibited in a scientific treatise."--_New York Sun._
+
+
+=THE FORMATION OF VEGETABLE MOULD, THROUGH THE ACTION OF WORMS, WITH
+OBSERVATIONS ON THEIR HABITS.= By CHARLES DARWIN, LL. D., F. R. S.,
+author of "On the Origin of Species," etc., etc. With Illustrations.
+12mo, cloth. Price, $1.50.
+
+  "Mr. Darwin's little volume on the habits and instincts of
+  earth-worms is no less marked than the earlier or more elaborate
+  efforts of his genius by freshness of observation, unfailing power
+  of interpreting and correlating facts, and logical vigor in
+  generalizing upon them. The main purpose of the work is to point out
+  the share which worms have taken in the formation of the layer of
+  vegetable mould which covers the whole surface of the land in every
+  moderately humid country. All lovers of nature will unite in
+  thanking Mr. Darwin for the new and interesting light he has thrown
+  upon a subject so long overlooked, yet so full of interest and
+  instruction, as the structure and the labors of the
+  earth-worm."--_Saturday Review._
+
+  "Respecting worms as among the most useful portions of animate
+  nature, Dr. Darwin relates, in this remarkable book, their structure
+  and habits, the part they have played in the burial of ancient
+  buildings and the denudation of the land, in the disintegration of
+  rocks, the preparation of soil for the growth of plants, and in the
+  natural history of the world."--_Boston Advertiser._
+
+
+=ANTS, BEES, AND WASPS.= A Record of Observations on the Habits of the
+Social Hymenoptera. By Sir JOHN LUBBOCK, Bart., M. P., F. R. S., etc.,
+author of "Origin of Civilization, and the Primitive Condition of
+Man," etc., etc. With Colored Plates. 12mo, cloth, $2.00.
+
+  "This volume contains the record of various experiments made with
+  ants, bees, and wasps during the last ten years, with a view to test
+  their mental condition and powers of sense. The principal point in
+  which Sir John's mode of experiment differs from those of Huber,
+  Forel, McCook, and others, is that he has carefully watched and
+  marked particular insects, and has had their nests under observation
+  for long periods--one of his ants' nests having been under constant
+  inspection ever since 1874. His observations are made principally
+  upon ants because they show more power and flexibility of mind; and
+  the value of his studies is that they belong to the department of
+  original research."
+
+  "We have no hesitation in saying that the author has presented us
+  with the most valuable series of observations on a special subject
+  that has ever been produced, charmingly written, full of logical
+  deductions, and, when we consider his multitudinous engagements, a
+  remarkable illustration of economy of time. As a contribution to
+  insect psychology, it will be long before this book finds a
+  parallel."--_London Athenaeum._
+
+
+=DISEASES OF MEMORY=: An Essay in the Positive Psychology. By TH.
+RIBOT, author of "Heredity," etc. Translated from the French by
+William Huntington Smith. 12mo, cloth, $1.50.
+
+  "M. Ribot reduces diseases of memory to law, and his treatise is of
+  extraordinary interest."--_Philadelphia Press._
+
+  "Not merely to scientific, but to all thinking men, this volume will
+  prove intensely interesting."--_New York Observer._
+
+  "M. Ribot has bestowed the most painstaking attention upon his
+  theme, and numerous examples of the conditions considered greatly
+  increase the value and interest of the volume."--_Philadelphia North
+  American._
+
+  "To the general reader the work is made entertaining by many
+  illustrations connected with such names as Linnaeus, Newton, Sir
+  Walter Scott, Horace Vernet, Gustave Dore, and many
+  others."--_Harrisburg Telegraph._
+
+  "The whole subject is presented with a Frenchman's vivacity of
+  style."--_Providence Journal._
+
+  "It is not too much to say that in no single work have so many
+  curious cases been brought together and interpreted in a scientific
+  manner."--_Boston Evening Traveller._
+
+
+=MYTH AND SCIENCE.= By TITO VIGNOLI. 12mo, cloth, price, $1.50.
+
+  "His book is ingenious; ... his theory of how science gradually
+  differentiated from and conquered myth is extremely well wrought
+  out, and is probably in essentials correct."--_Saturday Review._
+
+  "The book is a strong one, and far more interesting to the general
+  reader than its title would indicate. The learning, the acuteness,
+  the strong reasoning power, and the scientific spirit of the author,
+  command admiration."--_New York Christian Advocate._
+
+  "An attempt made, with much ability and no small measure of success,
+  to trace the origin and development of the myth. The author has
+  pursued his inquiry with much patience and ingenuity, and has
+  produced a very readable and luminous treatise."--_Philadelphia
+  North American._
+
+  "It is a curious if not startling contribution both to psychology
+  and to the early history of man's development."--_New York World._
+
+
+=MAN BEFORE METALS.= By N. JOLY, Professor at the Science Faculty of
+Toulouse; Correspondent of the Institute. With 148 Illustrations,
+12mo. Cloth, $1.75.
+
+  "The discussion of man's origin and early history, by Professor De
+  Quatrefages, formed one of the most useful volumes in the
+  'International Scientific Series,' and the same collection is now
+  further enriched by a popular treatise on paleontology, by M. N.
+  Joly, Professor in the University of Toulouse. The title of the
+  book, 'Man before Metals,' indicates the limitations of the writer's
+  theme. His object is to bring together the numerous proofs,
+  collected by modern research, of the great age of the human race,
+  and to show us what man was, in respect of customs, industries, and
+  moral or religious ideas, before the use of metals was known to
+  him."--_New York Sun._
+
+  "An interesting, not to say fascinating volume."--_New York
+  Churchman._
+
+
+=ANIMAL INTELLIGENCE.= By GEORGE J. ROMANES, F. R. S., Zooelogical
+Secretary of the Linnaean Society, etc. 12mo. Cloth, $1.75.
+
+  "My object in the work as a whole is twofold: First, I have thought
+  it desirable that there should be something resembling a text-book
+  of the facts of Comparative Psychology, to which men of science, and
+  also metaphysicians, may turn whenever they have occasion to
+  acquaint themselves with the particular level of intelligence to
+  which this or that species of animal attains. My second and much
+  more important object is that of considering the facts of animal
+  intelligence in their relation to the theory of descent."--_From the
+  Preface._
+
+  "Unless we are greatly mistaken, Mr. Romanes's work will take its
+  place as one of the most attractive volumes of the 'International
+  Scientific Series.' Some persons may, indeed, be disposed to say
+  that it is too attractive, that it feeds the popular taste for the
+  curious and marvelous without supplying any commensurate discipline
+  in exact scientific reflection; but the author has, we think, fully
+  justified himself in his modest preface. The result is the
+  appearance of a collection of facts which will be a real boon to the
+  student of Comparative Psychology for this is the first attempt to
+  present systematically well-assured observations on the mental life
+  of animals."--_Saturday Review._
+
+  "The author believes himself, not without ample cause, to have
+  completely bridged the supposed gap between instinct and reason by
+  the authentic proofs here marshaled of remarkable intelligence in
+  some of the higher animals. It is the seemingly conclusive evidence
+  of reasoning; powers furnished by the adaptation of means to ends in
+  cases which can not be explained on the theory of inherited aptitude
+  or habit."--_New York Sun._
+
+
+=THE SCIENCE OF POLITICS.= By SHELDON AMOS, M. A., author of "The
+Science of Law," etc. 12mo. Cloth, $1.75.
+
+  "To the political student and the practical statesman it ought to be
+  of great value."--_New York Herald._
+
+  "The author traces the subject from Plato and Aristotle in Greece,
+  and Cicero in Rome, to the modern schools in the English field, not
+  slighting the teachings of the American Revolution or the lessons of
+  the French Revolution of 1793. Forms of government, political terms,
+  the relation of law, written and unwritten, to the subject, a
+  codification from Justinian to Napoleon in France and Field in
+  America, are treated as parts of the subject in hand. Necessarily
+  the subjects of executive and legislative authority, police, liquor,
+  and land laws are considered, and the question ever growing in
+  importance in all countries, the relations of corporations to the
+  state."--_New York Observer._
+
+
+=THE FUNDAMENTAL CONCEPTS OF MODERN PHILOSOPHIC THOUGHT, CRITICALLY
+AND HISTORICALLY CONSIDERED.= By RUDOLPH EUCKEN, Ph. D., Professor in
+Jena. With an Introduction by NOAH PORTER, President of Yale College.
+One vol., 12mo, 304 pages. Cloth. Price, $1.75.
+
+  President Porter declares of this work that "there are few books
+  within his knowledge which are better fitted to aid the student who
+  wishes to acquaint himself with the course of modern speculation and
+  scientific thinking, and to form an intelligent estimate of most of
+  the current theories."
+
+
+=MIND IN THE LOWER ANIMALS IN HEALTH AND DISEASE.= By W. LAUDER
+LINDSAY, M. D., F. R. S. E., etc. 2 vols., 8vo. Cloth, $4.00.
+
+  "The author of this work, which, regarded merely as an accumulation
+  of verified and classified facts, is a unique and precious
+  contribution to the data of comparative psychology, claims that he
+  entered on his inquiry without any theory to defend, support, or
+  illustrate. We are bound to say that, while his general conclusions
+  are boldly and continually avowed, his claim of fairness and caution
+  is justified by his method of examining particular phenomena; that
+  he seems willing at all times to renounce any impression or belief
+  which is shown to be scientifically untenable."--_New York Sun._
+
+  "In this work--two volumes of over 500 pages--Dr. Lindsay marshals a
+  proportionately large number of facts against those philosophers who
+  maintain that the intelligence of man differs in kind and not simply
+  in degree from that of the lower animals. It is one purpose of his
+  book to show that the main differences between man and the lower
+  animals exist rather in their physical than in their mental
+  structure. In this way of thinking, all animals possess not the
+  semblance of, but the true substance of mind and will."--_New York
+  World._
+
+  "So far as we are aware there has been no treatise upon the subject
+  of animal intelligence so broad in its foundations, so well
+  considered, or so scientific in its methods of inquiry, as that
+  which has been prepared by Dr. W. Lauder Lindsay in two large
+  volumes, the first being devoted to a study of animal mind in
+  health, and the second to animal mind in disease. We may safely say
+  that his work is, in some respects, the most important essay of the
+  kind that has yet been undertaken. His observations have been
+  supplemented by a thorough mastery of the history and literature of
+  the subject, and hence his conclusions rest upon the broadest
+  possible foundation of safe induction. There is a good analytical
+  index to the book, as there ought to be to every work of the
+  kind."--_New York Evening Post._
+
+
+=THE ELEMENTARY PRINCIPLES OF SCIENTIFIC AGRICULTURE.= By N. T.
+LUPTON, LL. D., Professor of Chemistry in Vanderbilt University,
+Nashville, Tenn. 18mo. Cloth. Price, 45 cents.
+
+
+=A GLOSSARY OF BIOLOGICAL, ANATOMICAL, AND PHYSIOLOGICAL TERMS.= By
+THOMAS DUNMAN. Small 8vo. Cloth. 161 pages. Price, $1.00.
+
+  "It has been the author's task to furnish here a small and
+  convenient but very complete glossary of those terms; and he has
+  done this so well, both in his choice of terms for definition and in
+  his clear exposition of their etymological and technical meaning, as
+  to leave nothing to be desired in this direction."--_New York
+  Evening Post._
+
+
+   _For sale by all booksellers, or any work sent by mail, post-paid,
+                         on receipt of price._
+
+                      D. APPLETON & CO., Publishers,
+                     1, 3, & 5 Bond Street, New York.
+
+
+
+
+SCIENTIFIC LECTURES AND ESSAYS.
+
+
+=Popular Lectures on Scientific Subjects.= By H. HELMHOLTZ, Professor
+of Physics in the University of Berlin. First Series. Translated by E.
+ATKINSON, Ph. D., F. C. S. With an Introduction by Professor TYNDALL.
+With 51 Illustrations. 12mo. Cloth, $2.00.
+
+  _CONTENTS._--On the Relation of Natural Science to Science in
+  General.--On Goethe's Scientific Researches.--On the Physiological
+  Causes of Harmony in Music--Ice and Glaciers.--Interaction of the
+  Natural Forces.--The Recent Progress of the Theory of Vision.--The
+  Conservation of Force.--Aim and Progress of Physical Science.
+
+
+=Popular Lectures on Scientific Subjects.= By H. HELMHOLTZ. Second
+Series. 12mo. Cloth, $1.50.
+
+  _CONTENTS._--Gustav Magnus.--In Memoriam.--The Origin and
+  Significance of Geometrical Axioms.--Relation of Optics to
+  Painting.--Origin of the Planetary System.--On Thought in
+  Medicine.--Academic Freedom in German Universities.
+
+  "Professor Helmholtz's second series of 'Popular Lectures on
+  Scientific Subjects' forms a volume of singular interest and value.
+  He who anticipates a dry record of facts or a sequence of immature
+  generalization will find himself happily mistaken. In style and
+  method these discourses are models of excellence, and, since they
+  come from a man whose learning and authority are beyond dispute,
+  they may be accepted as presenting the conclusions of the best
+  thought of the times in scientific fields."--_Boston Traveler._
+
+
+=Science and Culture, and other Essays.= By Professor T. H. HUXLEY, F.
+R. S. 12mo. Cloth, $1.50.
+
+  "Of the essays that have been collected by Professor Huxley in this
+  volume, the first four deal with some aspect of education. Most of
+  the remainder are expositions of the results of biological research,
+  and, at the same time, illustrations of the history of scientific
+  ideas. Some of these are among the most interesting of Professor
+  Huxley's contributions to the literature of science."--_London
+  Academy._
+
+  "It is refreshing to be brought into converse with one of the most
+  vigorous and acute thinkers of our time, who has the power of
+  putting his thoughts into language so clear and forcible."--_London
+  Spectator._
+
+
+=Scientific Culture, and other Essays.= By JOSIAH PARSONS COOKE,
+Professor of Chemistry and Mineralogy in Harvard College. 12mo. Cloth,
+$1.00.
+
+  These essays are an outcome of a somewhat large experience in
+  teaching physical science to college students. Cambridge,
+  Massachusetts, early set the example of making the student's own
+  observations in the laboratory or cabinet the basis of all teaching,
+  either in experimental or natural history science; and this example
+  has been generally followed. "But in most centers of education,"
+  writes Professor Cooke, "the old traditions so far survive that the
+  great end of scientific culture is lost in attempting to conform
+  even laboratory instruction to the old academic methods of
+  recitations and examinations. To point out this error, and to claim
+  for science-teaching its appropriate methods, was one object of
+  writing these essays."
+
+
+       _For sale by all booksellers; or sent by mail, post-paid,
+                       on receipt of price._
+
+          New York: D. APPLETON & CO., 1, 3, & 5 Bond Street.
+
+
+
+
+
+End of the Project Gutenberg EBook of A History of the Growth of the
+Steam-Engine, by Robert H. Thurston
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