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| author | Roger Frank <rfrank@pglaf.org> | 2025-10-14 20:10:13 -0700 |
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| committer | Roger Frank <rfrank@pglaf.org> | 2025-10-14 20:10:13 -0700 |
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diff --git a/38403-h/38403-h.htm b/38403-h/38403-h.htm new file mode 100644 index 0000000..2ea9381 --- /dev/null +++ b/38403-h/38403-h.htm @@ -0,0 +1,5011 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" + "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> +<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> + <head> + <meta http-equiv="Content-Type" content="text/html;charset=iso-8859-1" /> + <meta http-equiv="Content-Style-Type" content="text/css" /> + <title> + The Project Gutenberg eBook of Scientific American Supplement No. 648, by Various. + </title> + <style type="text/css"> + +body { + margin-left: 12%; + margin-right: 12%; +} + + h1,h2,h3 { + text-align: center; + clear: both; +} + +p { + margin-top: .75em; + text-align: justify; + margin-bottom: .75em; + text-indent: 2em; +} + +a:focus, a:active { outline:#ffee66 solid 2px; background-color:#ffee66;} +a:focus img, a:active img {outline: #ffee66 solid 2px; } + +hr { + width: 33%; + margin-top: 2em; + margin-bottom: 2em; + margin-left: auto; + margin-right: auto; + clear: both; +} + +img {text-decoration: none;} + +sup {padding-left: 0.1em; vertical-align: text-top; line-height: 50%; font-size: small;} +sub {padding-left: 0.1em; vertical-align: text-bottom; line-height: 50%; font-size: small;} + +table { + margin-left: auto; + margin-right: auto; +} + +.pagenum { + position: absolute; + left: 88%; + font-size: smaller; + text-align: right; + color: gray; + margin-top: -0.45em; +} + +.blockquot { + margin-left: 5%; + margin-right: 5%; + text-align: justify; +} + +.center {text-align: center;} + +.smcap {font-variant: small-caps;} + +.caption {font-weight: bold;} +.figcenter {margin: auto; text-align: center;} +.figleft {float: left; clear: left; margin-left: 0; margin-bottom: 1em; + margin-top: 1em; margin-right: 1em; padding: 0; text-align: center;} +.figright {float: right; clear: right; margin-left: 1em; margin-bottom: 1em; + margin-top: 1em; margin-right: 0; padding: 0; text-align: center;} + +.footnote {margin-left: 10%; margin-right: 10%; width:80%; margin-bottom: 0.75em; + font-size: 0.9em; text-align: justify;} +.footnote .label { } +.fnanchor {vertical-align: super; font-size: 0.8em; text-decoration: none; position: relative;} + +.c2 {font-size: 1.50em; margin: 0.75em 0; font-weight: bolder; text-align: center;} +.c3 {font-size: 1.17em; margin: 0.83em 0; font-weight: bolder; text-align: center;} +.c4 {font-size: 1.00em; margin: 1.00em 0; font-weight: bolder; text-align: center;} + +.ChapterTopRule {width: 85%; height: 2px; color: black;} + + </style> + </head> +<body> + + +<pre> + +The Project Gutenberg EBook of Scientific American Supplement, No. 648, +June 2, 1888., by Various + +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: Scientific American Supplement, No. 648, June 2, 1888. + +Author: Various + +Release Date: December 24, 2011 [EBook #38403] + +Language: English + +Character set encoding: ISO-8859-1 + +*** START OF THIS PROJECT GUTENBERG EBOOK SC. AMERICAN SUPP., JUNE 2, 1888 *** + + + + +Produced by Juliet Sutherland, Henry Gardiner and the +Online Distributed Proofreading Team at https://www.pgdp.net. + + + + + + +</pre> + + +<hr class="ChapterTopRule" /> + +<div class="center" style="width: 25em; margin: auto; border: solid 1px; padding: 1em;"> +Transcriber's Note: The original publication has been replicated faithfully except as listed +<a href="#Changes" name="Start" id="Start">here</a>. +</div> + +<hr class="ChapterTopRule" /> +<!--001.png--><span class="pagenum"><a name="Page_10343" id="Page_10343">10343</a></span> + +<div class="figcenter" style="width: 700px;"> +<img src="images/title.png" width="700" height="157" alt="Scientific American overlays a contour of a city skyline." title="" /> +</div> + +<h1>SCIENTIFIC AMERICAN<br /> +SUPPLEMENT</h1> +<div class="c3">NEW YORK, JUNE 2, 1888</div> + +<div class="c4" style="float: left">Scientific American Supplement, Vol. XXV., No. 648.<br /> +Scientific American, established 1845.</div> + +<div class="c4" style="float: right">Scientific American Supplement, $5 a year.<br /> +Scientific American and Supplement, $7 a year.</div> + +<hr class="ChapterTopRule" /> + +<h2>TABLE OF CONTENTS.</h2> + +<div class="center" style="width: 40em; margin: auto;"> +<table border="0" cellpadding="6" cellspacing="0" summary="Contents"> +<tr><td align="left"> </td><td align="right">PAGE</td></tr> +<tr><td align="left">I. ARCHITECTURE.—<a href="#SIBLEY_COLLEGE_LECTURES_1887-88">Evolution of the Modern Mill.</a>—By <span class="smcap">C. J. H. Woodbury</span>.—Continuation of this Sibley College lecture, treating of the practical details of mill structures.</td><td align="right"><a href="#Page_10346">10346</a></td></tr> +<tr><td align="left">II. ASTRONOMY.—<a href="#CHANGES_IN_THE_STELLAR_HEAVENS">Changes in the Stellar Heavens.</a>—By <span class="smcap">J. E. Gore</span>, F.R.A.S.—Changes of color, brightness, and position in the fixed stars as attested to by the records of the ancient and modern astronomers.</td><td align="right"><a href="#Page_10355">10355</a></td></tr> +<tr><td align="left"><a href="#DISTANCE_AND_CONSTITUTION_OF_THE_SUN">Distance and Constitution of the Sun.</a>—Modern theories of the sun and difficulties in formulating a satisfactory explanation of all of its phenomena.</td><td align="right"><a href="#Page_10354">10354</a></td></tr> +<tr><td align="left">III. BOTANY.—<a href="#THE_COMMON_DANDELION">The Common Dandelion.</a>—By <span class="smcap">Frederick Leroy Sargent</span>.—The properties and life history of this common plant.—Its wonderful seed-distributing apparatus.—8 illustrations.</td><td align="right"><a href="#Page_10355">10355</a></td></tr> +<tr><td align="left">IV. CHEMISTRY.—<a href="#POISON_OF_THE_SOMALIS_EXTRACTED_FROM_THE_WOOD_OF_THE_OUABAIO">Poison of the Somalis extracted from the Wood of the Ouabaio.</a>—A recently investigated plant principle.</td><td align="right"><a href="#Page_10358">10358</a></td></tr> +<tr><td align="left">V. CIVIL ENGINEERING.—<a href="#TEST_OF_A_WROUGHT_IRON_DOUBLE_TRACK_FLOOR_BEAM1">Test of a Wrought Iron Double Track Floor Beam.</a>—By <span class="smcap">Alfred P. Boller</span>.—A test pushed to actual rupture of a full-sized member of a bridge.—1 illustration.</td><td align="right"><a href="#Page_10344">10344</a></td></tr> +<tr><td align="left"><a href="#TIMBER_AND_SOME_OF_ITS_DISEASES2_By_H_Marshall_Ward">Timber and Some of its Diseases.</a>—By <span class="smcap">H. Marshall Ward</span>.—Part V. of this exhaustive treatise of the deterioration of one of the great structural materials.—1 illustration.</td><td align="right"><a href="#Page_10345">10345</a></td></tr> +<tr><td align="left"><a href="#IMPROVED_TORPEDO_BOAT">Improved Torpedo Boat.</a>—1 illustration.</td><td align="right"><a href="#Page_10348">10348</a></td></tr> +<tr><td align="left">VI. ELECTRICITY.—<a href="#EFFECT_OF_CHLORINE_ON_THE_ELECTRO-MOTIVE_FORCE_OF_A_VOLTAIC_COUPLE6">Effect of Chlorine on the Electro-motive Force of a Voltaic Couple.</a>—By <span class="smcap">D. G. Gore</span>, F.R.S.—A very curious investigation, disclosing the sudden change in E. M. F. produced by a definite addition of chlorine.</td><td align="right"><a href="#Page_10351">10351</a></td></tr> +<tr><td align="left"><a href="#ON_A_THEORY_CONCERNING_THE_SUDDEN_LOSS_OF_MAGNETIC_PROPERTIES_OF_IRON_AND">On a Theory Concerning the Sudden Loss of Magnetic Properties of Iron and Nickel.</a>—By Mr. <span class="smcap">A. Tomlinson</span>, B.A.—A new theory, involving the probable rearrangement of the molecules or "magnetic atoms" of the metals in question.</td><td align="right"><a href="#Page_10358">10358</a></td></tr> +<tr><td align="left"><a href="#The_Passive_State_of_Iron_and_Nickel">The Passive State of Iron and Nickel.</a>—Note of this curious phenomenon.</td><td align="right"><a href="#Page_10347">10347</a></td></tr> +<tr><td align="left"><a href="#THE_WIMSHURST_INFLUENCE_MACHINE">The Wimshurst Electric Machine.</a>—Illustration of 13½ inch sparks produced by it.—1 illustration.</td><td align="right"><a href="#Page_10352">10352</a></td></tr> +<tr><td align="left"><a href="#THE_APPLICATION_OF_ELECTRICITY_TO_LIGHTING_AND_WORKING5">The Application of Electricity to Lighting and Working.</a>—By <span class="smcap">W. H. Preece</span>.—Lecture I.</td><td align="right"><a href="#Page_10350">10350</a></td></tr> +<tr><td align="left">VII. ENTOMOLOGY.—<a href="#SYSTEMATIC_RELATIONS_OF_PLATYPSYLLUS_AS_DETERMINED_BY_THE_LARVA12">Systematic Relations of Platypsyllus as determined by the Larva.</a>—By Dr. <span class="smcap">C. V. Riley</span>.—An important contribution to entomological science, a paper read at the meeting of the National Academy of Science, April 20, 1888.—4 illustrations.</td><td align="right"><a href="#Page_10356">10356</a></td></tr> +<tr><td align="left">VIII. HYGIENE.—Reducing Obesity—Note of general principles to be applied to diet and life. {Transcriber: Omitted by publisher.}</td><td align="right"><a href="#Page_10352">10352</a></td></tr> +<tr><td align="left"><a href="#THE_CARE_OF_THE_EYES8">The Care of the Eyes.</a>—By Prof. <span class="smcap">David Webster</span>.—A practical and scientific examination of how to preserve the eyesight and of the use and abuse of this important organ of sense.</td><td align="right"><a href="#Page_10352">10352</a></td></tr> +<tr><td align="left"><a href="#SANITATION_IN_MASSACHUSETTS">Sanitation in Massachusetts.</a></td><td align="right"><a href="#Page_10352">10352</a></td></tr> +<tr><td align="left">IX. MECHANICAL ENGINEERING.—<a href="#HYDRAULIC_TUBE_PRESS">Hydraulic Tube Press</a>.—An extraordinarily powerful press for striking up tubes from flat plates.</td><td align="right"><a href="#Page_10345">10345</a></td></tr> +<tr><td align="left"><a href="#THE_DISTRIBUTION_OF_HYDRAULIC_POWER_IN_LONDON">The Distribution of Hydraulic Power in London.</a>—A recent system introduced in London, with description of the plant and distribution pipes.</td><td align="right"><a href="#Page_10344">10344</a></td></tr> +<tr><td align="left"><a href="#THE_ONE_HUNDRED_AND_TWENTY_TON_SHEARS_OF_THE_PORT_OF_MARSEILLES">The One Hundred and Twenty Ton Shears of the Port of Marseilles.</a>—An immense set of hoisting apparatus described and illustrated.—3 illustrations.</td><td align="right"><a href="#Page_10343">10343</a></td></tr> +<tr><td align="left">X. PHOTOGRAPHY.—<a href="#COLORED_PHOTOGRAPHY">Colored Photography.</a>—Mr. <span class="smcap">J. E. Mayall's</span> recent advances in this phase of photography.</td><td align="right"><a href="#Page_10349">10349</a></td></tr> +<tr><td align="left">XI. PHYSICS.—<a href="#SCIENTIFIC_APPARATUS_AT_THE_MANCHESTER_ROYAL_JUBILEE_EXHIBITION">Scientific Apparatus at the Manchester Royal Jubilee Exhibition.</a>—Notes of the most interesting electrical, photometrical, and communicating apparatus.</td><td align="right"><a href="#Page_10348">10348</a></td></tr> +<tr><td align="left"><a href="#THE_SPECTRA_OF_OXYGEN">The Spectra of Oxygen.</a>—Interesting investigations of absorption spectra of oxygen.</td><td align="right"><a href="#Page_10358">10358</a></td></tr> +<tr><td align="left">XII. SURGERY.—<a href="#PAPILLOMATOUS_TUMOR_OF_THE_BLADDER_DEMONSTRATED_BY_MEANS_OF_LISTERS">Papillomatous Tumor of the Bladder, demonstrated by Means of Lister's Electro-cystoscope.</a>—By <span class="smcap">F. N. Otis</span>, M.D.—An interesting instance of the use of an exploratory electric light.—2 illustrations.</td><td align="right"><a href="#Page_10354">10354</a></td></tr> +<tr><td align="left"><a href="#TUMORS_OF_THE_BLADDER">Tumors of the Bladder Diagnosed by Means of the Electro-Endoscopic Cystoscope.</a>—By Dr. <span class="smcap">Max Nitze</span>.—The same general subject in further detail, giving the German practice.—5 illustrations.</td><td align="right"><a href="#Page_10353">10353</a></td></tr> +<tr><td align="left">XIII. TECHNOLOGY.—<a href="#FUTURE_PROSPECTS_FOR_GAS_COMPANIES4">Future Prospects for Gas Companies.</a>—By Mr. <span class="smcap">Thos. Wood</span>.—Fuel and oil gas and the future Utopia of improved gas manufacturing.—The ideal gas company of after days.—A valuable and suggestive paper.</td><td align="right"><a href="#Page_10349">10349</a></td></tr> +<tr><td align="left"><a href="#ADVERTISEMENTS">Advertisements.</a></td><td align="right"><a href="#Page_10358">10358</a></td></tr> +</table></div> +<hr class="ChapterTopRule" /> + +<h2><a name="THE_ONE_HUNDRED_AND_TWENTY_TON_SHEARS_OF_THE_PORT_OF_MARSEILLES" +id="THE_ONE_HUNDRED_AND_TWENTY_TON_SHEARS_OF_THE_PORT_OF_MARSEILLES"></a>THE +ONE HUNDRED AND TWENTY TON SHEARS OF THE PORT OF MARSEILLES.</h2> + +<p>For a quarter of a century maritime nations have been continuously engaged +in improving the mechanical appliances of their large ports. The use of +tracks to bring goods to be placed on vessels as near as possible to the +shipping point, the substitution of oblique moles for perpendicular ones +in large docks, the creation of a hydraulic method of loading and +unloading through movable cranes (which will perhaps in a near future cede +to an electrical one), constitute the means most used for expediting +transshipments and reducing the expense of them to a minimum. But, at the +same time that the facilities for all kinds for handling packages have +been increased, it has also become necessary to greatly increase the power +of the machines applied to them. The construction of large packets now +requires the putting in place of boilers of great weight, and the adoption +of the huge pieces that compose the artillery of ironclads necessitates +the use of force that has been unknown up to recent times.</p> + +<div class="figcenter" style="width: 734px;"> +<img src="images/i001a-1.png" width="734" height="455" alt="Diagram of forces and dimensions." title="" /> +<span class="caption"><span class="smcap">Fig. 1.</span>—DIAGRAM OF SHEARS.</span> +</div> + +<div class="figcenter" style="width: 460px; padding-top: 4em;"> +<img src="images/i001-2.jpg" width="460" height="700" alt="A crane picking up a barge." title="" /> +<span class="caption"><span class="smcap">Fig. 2.</span>—ONE +HUNDRED AND TWENTY TON SHEARS OF THE PORT OF +MARSEILLES.</span> +</div> + +<p>At present, then, we could no longer be content with manual power, acting +upon windlasses or capstans, for lifting and shifting. It has become +necessary to apply steam or hydraulic motors to these operations. Of +these, the latter are the most used, on account of their easy operation +and their submitting to the greatest stresses with a very satisfactory +proportionality of the expenditure of motive power. One of the most +remarkable of such apparatus is the one that the Compagnie de Fives-Lille +has recently set up on one of the moles of the national dock at +Marseilles, for the service of the chamber of commerce, and this merits a +description so much the more in that it is an important improvement upon +the analogous apparatus now in use in other ports.</p> + +<p>According to the conditions of the programme, powers of 25, 75, and 120 +tons had to be obtained at will, with a proportional output of water, and +the load had to be lifted 22 ft. above the quay and carried horizontally +from 28 ft. beyond the edge to 16 ft. in the rear, so that the load might +be taken from a ship and deposited upon a wagon, and <i>vice versa</i>. The +shears, then, had to be capable of performing two operations, viz., of +lifting the load and of carrying it horizontally. To facilitate the +description, we shall first make known the arrangements that assure the +second operation.</p> + +<p>The apparatus is of the type known as oscillating tripod. The tripod +consists of two lateral iron plate uprights, A A (Fig. 1), resting upon +the wharf wall, and of a beam, B, jointed to them above and connected +below with the head of the piston of a hydraulic press. This latter rests +upon an iron plate frame, solidly bolted to masonry. The piston pulls the +beam, B, toward it when it descends, and carries along in the same motion +the shears, A, as well as the load suspended from their point of junction, +and the load is thus carried to a distance of 16 ft. from the edge of the +wharf in order to be placed upon a wagon. Conversely, if the piston rises, +it pushes before it the entire framework, as well as the lifting +apparatus, the hook of which travels 28 ft. beyond the edge of the wharf.</p> + +<p>The lifting apparatus consists likewise of a hydraulic press suspended +from the summit of the tripod; but, in order to prevent the joints of the +cylinder from working under the action of the load, which would tend to +open them and cause leakages, it is not suspended from the very axis of +the junction of the shears. The cylinder rests directly upon a huge +stirrup 45 ft. in length, the arms alone of which are affixed to the axis, +through a Cardan joint. Under such circumstances, +<!--002.png-->the stress of the load +carried by the piston rod is exerted solely upon the branches of the +stirrup, and the sides of the cylinder work only under the pressure of the +motive water. The latter is introduced at the base of the press, through a +valve that a special workman, standing upon a platform supported by the +stirrup, maneuvers at will.</p> + +<p>It will be seen that the general principle applied for utilizing the +motive power is that of direct action. It has already been employed in a +few analogous apparatus constructed by Sir William Armstrong, especially +those of the arsenal of Spezia and of the Elswick cannon foundry, but +solely for the lifting press. This is the first time that use has been +made of it to effect the oscillating motion corresponding to the +horizontal shifting of the load. This was formerly done through the +intermedium of a mechanism that, aside from its complication and higher +cost, presented the inconvenience of absorbing a large quantity of force +in friction; besides, the direct action permits of performing the +maneuvers much more quickly by the use of the water in reserve contained +in the accumulators.</p> + +<p>Another important improvement, likewise due to the Compagnie Fives-Lille, +consists in the addition of safety clicks, which engage with racks +parallel with the piston rod of each of the presses and movable with it. +The clicks, on the contrary, are jointed to axes fixed on the bottom of +the cylinders. This arrangement presents the following advantages: If a +leakage occurs in the joints or feed pipe of the hoisting press, the +descent of the load can be stopped instantaneously, thus preventing the +grave damage that would be done to ships and even to the shears themselves +by the descent of a 120 ton load, however slow it might be. As regards the +oscillating press, this arrangement permits of fixing the base of the +connecting beam at any point whatever of its travel, when it is desired to +dismount the piston. Further, it permits of maintaining the shears in an +invariable position in case of sudden damages to the piping.</p> + +<div class="figcenter" style="width: 541px;"> +<img src="images/i001a-3.png" width="541" height="165" alt="Cross-section diagram." title="" /> +<span class="caption"><span class="smcap">Fig. 3.</span>—AUTOMATIC MULTIPLIER.</span> +</div> + +<p>In order to produce the three powers of 25, 75, and 120 tons required by +the programme, and at the same time expend in each case a corresponding +quantity of water under pressure, it is of course necessary to cause the +pressure of the motive water to vary in the same proportion as the stress +to be extended. This result is reached by calculating the diameter of the +two cylinders in such a way as to obtain the mean power of 75 tons, in +making the water of the general conduit act directly under the normal +pressure of 50 atmospheres. For the powers of 25 and 120 tons, use is made +of an automatic multiplier, that consists of two cylinders arranged end to +end, in which move pistons, A and B (Fig. 3), of different diameters. When +it is a question of lifting 120 tons, the water at 50 atmospheres actuates +the piston, A, and the other forces into the lifting cylinder motive water +under a much greater pressure. If the load to be lifted is but 25 tons, +the water at 50 atmospheres actuates the piston, B, and A forces the water +into the same cylinder at a much lower pressure. The same operations are +effected in the other cylinder when the extreme loads of 25 and 120 tons +are moved.</p> + +<p>The shears are likewise provided with a hydraulic cylinder, E (Fig. 1), +placed on the back of the beam, B, and serving, through a cable, to bring +the piston of the large cylinder to the end of its upward stroke, and for +certain accessory work.</p> + +<p>Finally, the apparatus as a whole is completed by an accumulator +containing in reserve a large part of the water necessary for each +operation.</p> + +<p>The apparatus is capable of lifting a maximum load of 120 tons from 22 +feet beneath the wharf to 22 feet above, and of +<!--003.png--><span class="pagenum"><a name="Page_10344" id="Page_10344">10344</a></span>moving +it from 28 feet +beyond the edge to 16 feet back of it, say a total of 44 feet. The +cylinders of the lifting and oscillating presses are 1¾ feet in diameter +and 4 inches in thickness. The stroke of the second is 22½ feet. The +length of the uprights is 110½ feet and that of the connecting beam is 109 +feet. The apparatus has been tested under satisfactory conditions with a +load of 140 tons.—<i>La Nature.</i></p> + +<hr class="ChapterTopRule" /> + +<h2><a name="THE_DISTRIBUTION_OF_HYDRAULIC_POWER_IN_LONDON" +id="THE_DISTRIBUTION_OF_HYDRAULIC_POWER_IN_LONDON"></a>THE +DISTRIBUTION OF HYDRAULIC POWER IN LONDON.</h2> + +<p>At a recent meeting of the Institution of Civil Engineers, a paper on the +above subject was read by Mr. Edward Bayzand Ellington, M. Inst. C. E. The +author observed that water power was no new force, but that, as formerly +understood, it was limited in its application to systems of mechanism +suitable for the low pressures found in nature. The effects obtained by +the use of high pressure were so different in degree from all previous +experience, that a new name was needed, and had been found in the term +"hydraulic power." Bramah's genius produced the hydraulic press, and he +clearly foresaw the future development and great capabilities of his +system; but it was reserved for Lord Armstrong to work out and superintend +the intricate details that had to be developed before the system could be +made fully serviceable. The public supply of hydraulic power in London +constituted the latest development of this system. The hydraulic power was +supplied through mains charged by pumping at a pressure of 700 lb. per +square inch. The first and largest pumping station had been erected on a +site known as Falcon Wharf, about 200 yards east of Blackfriars Bridge. +The engine house at present contained four sets of pumping engines, each +set being capable of exerting 200 I. H. P.</p> + +<p>The engines were vertical compound, of a type comprising the advantages of +a three-throw pump with direct connection between the pump plungers and +the steam pistons. Each set of engines would deliver 240 gallons of water +per minute into the accumulators at 750 lb. pressure per square in. at a +piston speed of 200 ft. per minute. This was the normal speed of working; +but, when required, they could be worked at 250 ft. per minute, the +maximum delivery being 300 gallons per minute. The condensing water was +obtained from storage tanks over the engine house, and was returned by +circulating pumps to one or other of those tanks. The water delivered into +the mains was maintained all the year round at temperatures of between 60° +and 85°. The boilers were of the double flued Lancashire type, and were +made of steel. All were fitted with Vicars' mechanical stokers. At the +back of the boilers was a Green's economizer, consisting of ninety-six +tubes. The economizer and the stoker gear and worm were driven by a +Brotherhood three cylinder hydraulic engine. The reservoir of power +consisted of accumulators. The accumulators at the pumping station were +two in number, each having a ram 20 in. in diameter and 23 ft. stroke.</p> + +<p>The weight cases were of wrought iron, and were filled with iron slag. The +total weight of the case and load on each ram was approximately 106 tons, +corresponding to a pressure of 750 lb. per square in. The storage tanks +formed the roofs for the engine and boiler houses. The water for the power +supply was obtained from the river Thames, and was pumped into the tank +over the engines. The water passed through the filtering apparatus by +gravity into the filtered water tank over the boiler house, which was 7 +ft. below the level of the unfiltered water tank. The filters consisted of +cast iron cylinders, and each contained a movable perforated piston and a +perforated diaphragm, between which was introduced a quantity of broken +sponge; the sponge was compressed by means of hydraulic pressure from the +mains. The delivery of power water from the Falcon Wharf pumping station +was through four 6 in. mains. The most distant point of the mains from the +accumulators was at the west end of Victoria Street, and was 5,320 yards, +or just over three miles. To provide for all frictional loss in the pipes +and valves, the accumulators had been loaded to 750 lb., the stated +pressure supplied being 700 lb. per square in. The total length of the +mains at present laid was nearly twenty-seven miles. The mains were laid +in circuit, and there were stop valves at about every 400 yards, so that +any such section of main could be isolated.</p> + +<p>The method employed for detecting leakage was based upon an automatic +record of the number of gallons delivered into the mains, and in cases of +abnormal increase during the night, if found to arise during the early +hours of the morning, the mains were tested. The power water used was +invariably registered through meters on the exhaust pipes from the +machines, and from the meters passed to the drains. There was a sliding +scale of charges from 8s. to 2s. per 1,000 gallons at 700 lb. pressure per +square inch, designed to meet, as nearly as possible, the variable +conditions and requirements of consumers. The more continuous the use, the +lower the charges. The scale was intended chiefly for intermittently +acting machinery, and experience had fully proved that these rates were +sufficiently low to effect a large saving to the consumer in almost all +cases, whether for a large or a small plant. The author believed any idea +of supplying power from a central source at rates much below these to be +chimerical. The practical efficiency of the hydraulic system might be +fixed at from 50 to 60 per cent. of the power developed at the central +station. No other method of transmission would, he thought, show a better +result; and the general convenience and simplicity of the hydraulic system +were such that its use would hardly be affected, even if there were no +direct economy in the cost of working.</p> + +<p>In addition to the general supply of hydraulic power, in the City and +adjoining districts, to the six hundred and fifty machines at present +worked, a new departure had been taken by the application of hydraulic +power to an estate at Kensington Court—the name given to an area of about +seven acres opposite Kensington Gardens. Seventy houses and dwellings were +to be built on this estate, of which thirty had been already erected. Each +house was fitted with a hydraulic lift, taking the place of a back +staircase, and the power supply was provided on the estate expressly for +working these lifts. The driven machinery was of as great importance to an +economical and satisfactory result as +<!--004.png-->the distributing plant, but this +obvious fact was not always understood. General regulations had been +prepared by the author, defining the conditions to be observed by +manufacturers in fitting up machinery for connection to the power mains.</p> + +<p>They were intended to secure safety, and an efficient registration of the +quantity of power used; but they left the question of the economy and of +the efficiency of the machines to be settled between the consumers and the +makers. In London more lifts were working from the mains and more power +was used by them than by any other description of machinery. The number of +all classes at present at work was over four hundred. The principal types +in use were fully described. In some cases there had been, by adopting the +public supply, a saving in the cost of working of about 30 per cent., as +compared with the steam pumping plant previously in use.</p> + +<p>Lifts were now becoming so general, and the number of persons who used +them was so great, that the author considered it necessary to urge the +importance of securing the greatest possible safety in their construction, +by the general adoption of the simple ram. Suspended lifts depended on the +sound condition of the ropes or chains from which the cages hung. As they +became worn and unreliable after a short period, it was usual to add +safety appliances to stop the fall of the cage in case of breakage of the +suspending ropes; but they could not be expected to act under all +circumstances. As an indication of the important part which lifts occupied +in a modern hotel, it might be mentioned that at the Hotel Metropole there +were, including the two passenger lifts and that for the passengers' +luggage, no less than seventeen hydraulic lifts in use day and night, +while the work done represented about 2,000 tons lifted 40 ft. in this +time. The next largest use of the power was for working hydraulic cranes +and hoists of various kinds along the river side, and in the city +warehouses. It often happened that the pressure in the power mains was not +sufficient for pressing purposes.</p> + +<p>The apparatus known as an intensifier was then used, by which any pressure +required could be obtained. Hydraulic power was also used at Westminster +Chambers, and elsewhere, for the purpose of pumping water from the chalk +for domestic use. The pump was set going in the evening and continued +working till the tanks were full, or until it was stopped in the morning. +For work of this kind, done exclusively at night, a discount was allowed +from the usual rates. Mr. Greathead's injector hydrant, made at the +Elswick works, had been in use to a limited extent in London in connection +with the power mains.</p> + +<p>A small jet of high pressure water, injected into a larger jet from the +water works mains, intensified the pressure of the latter in the delivery +hose, and also increased the quantity. By this means a jet of great power +could be obtained at the top of the highest building without the +intervention of fire engines. This apparatus enabled the hydraulic power +supply to act as a continuous fire engine wherever the mains were laid, +and was capable of rendering the greatest assistance +<!--005.png-->in the extinction of +fire; but there was an apathy on the subject of its use difficult to +understand. In Hull the corporation had put down a number of these +hydrants in High Street, where the hydraulic power mains were laid, and +they had been used with great success at a fire in that street. The number +of machines under contract to be supplied with power was sufficient, with +a suitable reserve, to absorb the full capacity of the station at Falcon +Wharf, and another station of about equal capacity was now in course of +erection at Millbank Street, Westminster. The works had been carried out +jointly by the author and Mr. Corbet Woodall, M. Inst. C. E.; Mr. G. +Cochrane had been resident engineer and superintendent. The pumping +engines, accumulators, valves, etc., and a considerable portion of the +consumers' machinery, had been constructed at the Hydraulic Engineering +Works, Chester. Sir James Allport, Assoc. Inst. C. E., who was the first +to adopt hydraulic power for railway work, had been associated with the +enterprise from the commencement of its operations in 1882. His wide +influence and extended experience had greatly assisted the commercial +development of the undertaking.</p> + +<hr class="ChapterTopRule" /> + +<h2><a name="TEST_OF_A_WROUGHT_IRON_DOUBLE_TRACK_FLOOR_BEAM1" +id="TEST_OF_A_WROUGHT_IRON_DOUBLE_TRACK_FLOOR_BEAM1"></a>TEST +OF A WROUGHT IRON DOUBLE TRACK FLOOR BEAM.<a name="FNanchor_1_1" +id="FNanchor_1_1"></a><a href="#Footnote_1_1" class="fnanchor">[1]</a></h2> + +<div class="c3">By <span class="smcap">Alfred P. Boller</span>, Mem. Am. Soc. C. E.</div> + +<p>Testing to rupture actual bridge members is always a matter of great +scientific interest, and while the record is quite extensive in eye bars, +posts, or small parts, the great cost, time, and inconvenience of handling +heavy girders has prevented experiment in that direction. In fact, the +writer is unaware of any experiment upon compound riveted beams on a large +scale, as actually used, until the experiment recorded below was made +under his supervision. The beam was an exact duplicate of those in use on +a bridge, about which more or less controversy had arisen as to their +practical safety, and the test was made under, as near as possible, actual +conditions of attachment and loading. The annexed drawing shows the form +and proportion of the beam and connection with the posts, together with +the position of the track stringers. The actual static loads to which the +beam could be subjected by the heaviest engines in use on the road, with +weight of floor, is 40,000 lb. at each stringer bearing, the strains +computed therefrom being as follows: Flange strains at <i>m</i>, 3,800 lb. per +square inch; at <i>a</i>, 5,700 lb. per square inch; at <i>b</i>, 6,400 lb. per +square inch. Shear strains in web, between <i>a</i> and <i>b</i>, 2,600 lb. per +square inch. Shear strains in web, between <i>a</i> and end, 8,000 lb. per +square inch at least section, or where the web is 2 feet 4 inches deep, or +42 diameters between angle iron.</p> + +<div class="footnote"><p><a name="Footnote_1_1" id="Footnote_1_1"></a><a class="label" href="#FNanchor_1_1">[1]</a> Abstract of a paper read before the American Society of Civil +Engineers, November 16, 1887.</p></div> + +<div class="figcenter" style="width: 600px;"> +<img src="images/i004-1.png" width="600" height="432" alt="Fractured beam." title="" /> +</div> + +<div class="figcenter" style="width: 700px;"> +<img src="images/i006t.png" width="700" height="449" alt="Test setup with beam and dimensions." title="" /> +<a href="images/i006.png" target="_blank">Larger.</a> +</div> + +<p><i>Rivets.</i>—All rivets <sup>7</sup>⁄<sub>8</sub> inch diameter, or <sup>15</sup>⁄<sub>26</sub> inch when driven to fill +holes; area of section, 0.6 square inch; bearing area, diameter × <sup>3</sup>⁄<sub>8</sub> +plate = 0.35 square inch, and for <sup>1</sup>⁄<sub>2</sub> inch plate 0.47 square inch. Post +attachment, +<!--006.png--><span class="pagenum"><a name="Page_10345" id="Page_10345">10345</a></span>considering +all the twenty-six rivets doing duty, yields +rivet strain as follows: In shear, single 5,000 lb. per square inch: and +bearing area—<sup>1</sup>⁄<sub>2</sub> inch plate—6,600 lb. per square inch.</p> + +<p><i>Connection of <sup>3</sup>⁄<sub>8</sub> Web to Flange Angles.</i>—Taking the forty rivets between +ends of girder and second stringer, the horizontal strain difference is +162,000 lb., the rivets being strained 3,400 lb. per square inch double +shear, and 11,600 lb. per square inch bearing area. Taking distance from +ends to first stringer, the horizontal strain difference is 105,000 lb., +yielding on twenty rivets 4,200 lb. per square inch double shear, and +15,000 lb. per square inch bearing area. Taking a short distance of 2 feet +from ends, the horizontal strain is 70,000 lb. on ten rivets, giving 5,800 +lb. per square inch double shear, and 20,000 lb. per square inch bearing +area. In these girders the weakness feared was in the end flange riveting +and shear in end web, and caused the test recorded below. The test was +recently made at the works of the Keystone Bridge Company, by means of +hydraulic power applied at stringer points. Convenience made it necessary +to make the test with the beam blocked up horizontal on the ground, so +that the weight of the beam is necessarily neglected. The beam was +connected with a pair of posts, precisely as in the actual structure, +between which an additional girder was framed as a reaction base for the +rams. The annexed diagram shows the general arrangements. The hydraulic +power was derived from the testing machine plant of the Keystone +establishment, and the deflections measured from a fine wire parallel to +the lower flange, and about 3 inches therefrom. The diameter of the ram +was 10 inches; area 78.54 inches. The record was as follows:</p> + +<div class="center"> +<table border="0" cellpadding="4" cellspacing="0" summary="Loads and beam's response."> +<tr><td align="center">Gauge<br />reading.</td><td align="center">Load on each ram. lb.</td><td align="center">Deflections. <i>b</i> in.</td><td align="center">Total <i>b</i>' in.</td><td align="center">load. lb.</td></tr> +<tr><td align="right"> 565</td><td align="center">44,375</td><td align="center"><sup>1</sup>⁄<sub>8</sub></td><td align="center"><sup>1</sup>⁄<sub>8</sub></td><td align="center">177,500</td></tr> +<tr><td align="right">1130</td><td align="center">88,750</td><td align="center"><sup>5</sup>⁄<sub>16</sub></td><td align="center"><sup>5</sup>⁄<sub>16</sub></td><td align="center">355,000</td></tr> +<tr><td align="right">1412</td><td align="center">110,900</td><td align="center"><sup>3</sup>⁄<sub>8</sub></td><td align="center"><sup>3</sup>⁄<sub>8</sub></td><td align="center">443,600</td></tr> +<tr><td align="right"> </td><td align="center">No permanent set in above</td></tr> +<tr><td align="right">1695</td><td align="center">133,125 uncertain.</td><td align="center">—</td><td align="center">—</td><td align="center">532,500</td></tr> +<tr><td align="right"> </td><td align="center">Permanent set scant <sup>1</sup>⁄<sub>32</sub> inch.</td></tr> +<tr><td align="right">1980</td><td align="center">155,500 not recorded.</td><td align="center">—</td><td align="center">—</td><td align="center">622,000</td></tr> +<tr><td align="right"> </td><td align="center">Permanent set <sup>5</sup>⁄<sub>32</sub> inch.</td></tr> +<tr><td align="right">2080</td><td align="center">Failure commenced.</td><td align="center">—</td><td align="center">—</td><td align="center">653,500</td></tr> +</table></div> + +<p>Failure commenced through giving way of angle irons, beginning in a fine +seam in the first bend of the lower flange from the end support, the seam +being along the root of the angle, which continual pressure tore apart +across the angle as shown, when the web commenced to tear like a sheet of +paper, in direction and manner as exhibited on plate herewith—from +photograph. From some cause not apparent the deflections were not similar +at the symmetrical end rams, <i>a</i>, the point where the web failed—left +side—being sharply deflected. While the angles showed root fracture at +the opposite point, the web did not fail or show indications of so doing, +the deflection being on an easy curve. With the extreme yielding of the +lower flange angles, the angle brackets connecting girder with posts +commenced to go, tearing likewise along the root, and stripping the heads +from the extreme upper rivets as shown. The internal diaphragm connecting +the channel sides of the posts was unaffected. The rivets connecting the +ruptured flange with web appeared as perfect as when driven, and no +indication was disclosed, as far as it was possible to tell, of the holes +in the web elongating or any upsetting of bearing surface. There is no +telling what the web and rivets would have borne had not the solid angle +irons given way at the first bend. It is to be noted that flange plate +with leg of angle attached thereto was intact, showing no indication of +rupture.</p> + +<p><i>Discussion.</i>—Taking that stage of the experiment when a permanent set +was first noted—viz., <sup>1</sup>⁄<sub>32</sub> inch—the recorded load was 532,500 lb., or as +near as may be 3<sup>1</sup>⁄<sub>3</sub> times the basis on which the calculations in the +first part of this paper were made—40,000 lb. on each stringer, or +160,000 lb. total. Applying this ratio to the preceding computations, the +iron would be apparently strained as follows:</p> + +<div class="center"> +<table border="0" cellpadding="4" cellspacing="0" summary="Strains."> +<tr><td align="left" rowspan="3">Flanges at: </td><td align="left"><i>m</i> 3,800 × 3<sup>1</sup>⁄<sub>3</sub> = 12,600 lb. per square inch (psi).</td></tr> +<tr><td align="left"><i>a</i> 5,700 × 3<sup>1</sup>⁄<sub>3</sub> = 19,000 psi.</td></tr> +<tr><td align="left"><i>b</i> 6,400 × 3<sup>1</sup>⁄<sub>3</sub> = 21,200 psi.</td></tr> +<tr><td align="left"> </td></tr> +<tr><td align="left" rowspan="2">Web.</td><td align="left">Between <i>a</i> and <i>b</i>, 2,600 × 3<sup>1</sup>⁄<sub>3</sub> = 8,700 psi.</td></tr> +<tr><td align="left">At least section, 8,000 × 3<sup>1</sup>⁄<sub>3</sub> = 26,600 psi.</td></tr> +<tr><td align="left"> </td></tr> +<tr><td align="left" rowspan="6">Rivets.</td><td align="left">Post attachment:</td></tr> +<tr><td align="left"> Bearing area, 6,600 × 3<sup>1</sup>⁄<sub>3</sub> = 22,000 psi.</td></tr> +<tr><td align="left"> Single shear, 5,000 × 3<sup>1</sup>⁄<sub>3</sub> = 16,600 psi.</td></tr> +<tr><td align="left">Web and flange connections, end rivets:</td></tr> +<tr><td align="left"> Bearing area, 20,000 × 3<sup>1</sup>⁄<sub>3</sub> = 66,600 psi.</td></tr> +<tr><td align="left"> Double shear, 5,800 × 3<sup>1</sup>⁄<sub>3</sub> = 19,300 psi.</td></tr> +</table></div> + +<p>When failure in angles was first noted, the recorded load was 653,500 lb., +or slightly more than four times the computed basis of load, which would +increase the above strains about one-fifth, giving a calculated flange +strain when angle failed of some 15,000 lb. per square inch, and bearing +area strain on end flange and web rivets about 80,000 lb. per square inch, +neither of which could possibly be true, or the web would have torn out +from the rivets, and the flanges be perfectly sound, well within elastic +limits, although in the last case it is to be noted that the horizontal +table of the flange was perfectly sound, the flange failure commencing +primarily with a long split along the weld of the angle iron root, +throwing the whole flange duty upon the vertical legs of the angle iron, +when a rupture strain was quickly reached. Had the angles been rolled from +a solid ingot, or on the German method of developing from a flat instead +of from the ordinary welded pile, the strength of this beam would have +been largely increased. The prime weakness in this beam was due, +therefore, to the mode of manufacturing the angle irons, which were weak +along the weld at the root. This was also shown in the end bracket angles +uniting the beam to the posts. The writer deduces from this experiment +that a plate web is an exceedingly stiff member, much stiffer than is +commonly supposed; that the customary method of proportioning +rivets—viz., the horizontal component between any two given points +divided by allowable bearing pressure per square inch equals number of +rivets required—is not true, and that the friction due to power riveting +has enormous value. This beam was reported to the company interested as +practically safe by the writer, on general considerations, before the +experiment was made, and the opinion reaffirmed after the experiment.</p> + +<hr style="width: 45%;" /> + +<p>London Bridge cost $10,000,000. It is 900 feet long and 54 feet wide. +100,000 persons pass over it every twenty-four hours. The lamp posts are +made from cannon taken during the Peninsular War.<!--007.png--></p> + +<hr class="ChapterTopRule" /> + +<h2><a name="HYDRAULIC_TUBE_PRESS" id="HYDRAULIC_TUBE_PRESS"></a>HYDRAULIC TUBE PRESS.</h2> + +<p>Forming metal tubes from circular plates by pressing or forcing them, by +the aid of mandrels, through dies or annular rings, though comparatively a +modern manufacture, is carried on to a considerable extent, and with the +improvements that are almost daily being made in it, and the rapidly +extending use of such tubes, this extraordinary process bids fair to +become a most important manufacture.</p> + +<div class="figleft" style="width: 259px;"> +<img src="images/i007.png" width="259" height="700" alt="Press dwarfs man." title="" /> +</div> + +<p>The press illustrated here was designed and made by Messrs. Henry Bessemer +& Co., of Sheffield, for Mr. Samuel Walker, of Birmingham, for the +manufacture of tubes of large size, and also for making hollow steel +projectiles.</p> + +<p>The press is made entirely of Bessemer steel, and is of the three-column +construction, a strong casting of triangular form serving as a base of the +press; into this casting the three columns fit, and carry on their upper +ends a like casting, forming a top or entablature. Into this top casting +the main cylinder is fixed mouth downward, +<!--008.png-->concentric with the machine. +Two small cylinders for giving the return or upward stroke rest mouth +upward in the bottom casting at opposite sides. The two rams of these +cylinders pass through the ends of, and carry, a crosshead, upon which the +main ram rests. The two lifting rams are made long enough to pass through +holes in the top casting, and thus form guides to the crosshead and +mandrel.</p> + +<p>The main ram is 24 in. in diameter, and has a stroke of 12 ft. The press +is worked at a pressure of 3 tons per square inch, giving a down force of +1,300 tons. The two lifting rams are each 8½ in. in diameter, and give an +upward force of 300 tons. This large upward force is required for +stripping the tubes off the mandrels, in addition to raising the main ram +crosshead, etc.</p> + +<p>Referring to the engraving, the main cylinder is seen at the top with the +main ram carrying the crosshead, to which are connected the two lifting +rams, the cylinders for which extend below ground. By this arrangement a +reciprocating motion is obtained, rams only being used, the central ram +giving the downward thrust, and the two smaller side rams giving the +upward stroke.</p> + +<p>Mr. Walker has this press in operation, and from a disk of steel 3 ft. in +diameter, having a mean thickness of about 4 in., he has raised a tube or +cylinder with a solid end to it 3 ft. 6 in. long and 12 in. in diameter, +of a uniform thickness of about 1 in., and sanguine hopes are entertained +of producing greater results. Messrs. Bessemer & Co. are now making a +larger press of similar construction.—<i>Engineering.</i></p> + +<hr class="ChapterTopRule" /> + +<h2><a name="TIMBER_AND_SOME_OF_ITS_DISEASES2_By_H_Marshall_Ward" +id="TIMBER_AND_SOME_OF_ITS_DISEASES2_By_H_Marshall_Ward"></a>TIMBER, +AND SOME OF ITS DISEASES.<a name="FNanchor_2_2" +id="FNanchor_2_2"></a><a href="#Footnote_2_2" +class="fnanchor">[2]</a> By <span class="smcap">H. Marshall Ward</span>.</h2> + +<h3>VI.</h3> + +<p>If we turn our attention for a moment to the illustrations in the first +article, it will be remembered that our typical log of timber was clothed +in a sort of jacket termed the cortex, the outer parts of which constitute +what is generally known as the bark. This cortical covering is separated +from the wood proper by the cambium, and I pointed out that the cells +produced by divisions on the outside of the cambium cylinder are employed +to add to the cortex.</p> + +<div class="footnote"><p><a name="Footnote_2_2" id="Footnote_2_2"></a><a class="label" href="#FNanchor_2_2">[2]</a> Continued from <span class="smcap">Supplement</span>, No. 644, page 10281.</p></div> + +<p>Now this cortical jacket is a very complicated structure, since it not +only consists of numerous elements, differing in different trees, but it +also undergoes some very curious changes as the plant grows up into a +tree. It is beyond the purpose of these articles to enter in detail into +these anatomical matters, however; and I must refer the reader to special +text books for them, simply contenting myself here with general truths +which will serve to render clearer certain statements which are to follow.</p> + +<div class="figcenter" style="width: 700px;"> +<img src="images/i008.png" width="700" height="539" alt="Cross-section of bark." title="" /> +<span class="caption"><span class="smcap">Fig. 20.</span>—A piece of the cambium and cortical +jacket of a young oak, at the end of the first year. It may be regarded as +consisting of three parts, in addition to the cambium, C<i>a</i>. Beginning +from the outside, we have: 1. Cork cells, X, formed from the cork cambium, +C.C<i>a</i>: the cells developed on the inside of the latter, C<i>l</i>, are termed +collenchyma, and go to add to the cortex. 2. The cortex proper, consisting +of parenchyma cells, <i>pa</i>, some of which contain crystals. 3. The inner or +secondary cortex (termed <i>phloem</i> or bast), developed chiefly by the +activity of the cambium, C<i>a</i>: this phloem consists of hard bast fibers, +<i>hb</i>, sieve tubes, S, and cells, <i>c</i>, and is added to internally by the +cambium, C<i>a</i>, each year. It is also traversed by medullary rays, M<i>r</i>, +which are continuations of those in the wood. The dotted line, ψ, in +the cortical parenchyma indicates where the new cork cambium will be +developed: when this is formed, all the tissues (e.g. <i>pa</i>, C<i>l</i>) lying on +the outside of the new cork will die, and constitute (together with the +cork) the true <i>bark</i>.</span> +</div> + +<p>It is possible to make two generalizations, which apply not only to the +illustration (Fig. 20) here selected, but also to most of our timber +trees. In the first place, the cortical jacket, taken as a whole, consists +not of rigid lignified elements, such as the tracheids and fibers of the +wood, but of thin-walled, soft, elastic elements of various kinds, which +are easily compressed or displaced, and for the most part easily killed or +injured—I say for the most part easily injured, because, as we shall see +immediately, a reservation must be made in favor of the outermost tissue, +or cork and bark proper, which is by no means so easily destroyed, and +acts as a protection to the rest.</p> + +<p>The second generalization is, that since the cambium adds new elements to +the cortex on the inside of the latter, and since the cambium cylinder as +a whole is traveling radially outward—<i>i.e.</i>, further from the pith—each +year, as follows from its mode of adding the new annual rings of wood on +to the exterior of the older ones, it is clear that the cortical jacket as +a whole must suffer distention from within, and tend to become too small +for the enlarging cylinder of rigid wood and growing cambium combined. +Indeed, it is not difficult to see that unless certain provisions are made +for keeping up the continuity of the cortical tissues, they must give way +under the pressure from within. As we shall see, such a catastrophe is in +part prevented by a very peculiar and efficient process.</p> + +<p>Before we can understand this, however, we must +<!--009.png--><span class="pagenum"><a name="Page_10346" id="Page_10346">10346</a></span>take +a glance at the +structural characters of the whole of this jacket (Fig. 20). While the +branch or stem is still young, it may be conveniently considered as +consisting of three chief parts.</p> + +<p>(1) On the outside is a thin layer of flat, tabular cork cells (Fig. 20, +C<i>o</i>), which increase in number by the activity of certain layers of cells +along a plane parallel to the surface of the stem or branch. These cells +(C.C<i>a</i>) behave very much like the proper cambium, only the cells divided +off from them do not undergo the profound changes suffered by those which +are to become elements of the wood and inner cortex. The cells formed on +the outside of the line C.C<i>a</i> in fact simply become cork cells; while +those formed on the inside of the line C.C<i>a</i> become living cells (C<i>l</i>) +very like those I am now going to describe.</p> + +<p>(2) Inside this cork-forming layer is a mass of soft, thin-walled "juicy" +cells, <i>pa</i>, which are all living, and most of which contain granules of +chlorophyl, and thus give the green color to the young cortex—a color +which becomes toned down to various shades of olive, gray, brown, etc., as +the layers of cork increase with the age of the part. It is because the +corky layers are becoming thicker that the twig passes from green to gray +or brown as it grows older. Now, these green living cells of the cortex +are very important for our purpose, because, since they contain much food +material and soft juicy contents of just the kind to nourish a parasitic +fungus, we shall find that, whenever they are exposed by injury, etc., +they constitute an important place of weakness—nay, more, various fungi +are adapted in most peculiar ways to get at them. Since these cells are +for the most part living, and capable of dividing, also, we have to +consider the part they play in increasing the extent of the cortex.</p> + +<p>(3) The third of the partly natural, partly arbitrary portions into which +we are dividing the cortical jacket is found between the green, succulent +cells (<i>pa</i>) of the cortex proper (which we have just been considering) +and the proper cambium, C<i>a</i>, and it may be regarded as entirely formed +directly from the cambium cells. These latter, developed in smaller +numbers on the outside, toward the cortex, than on the inside, toward the +wood, undergo somewhat similar changes in shape to those which go to add +to the wood, but they show the important differences that their walls +remain unlignified, and for the most part very thin and yielding, and +retain their living contents. For the rest, we may neglect details and +refer to the illustration for further particulars. The tissue in question +is marked by S, <i>c</i>, <i>hb</i> in the figure, and is called <i>phloem</i> or bast.</p> + +<p>A word or two as to the functions of the cortex, though the subject +properly demands much longer discussion. It may be looked upon as +especially the part through which the valuable substances formed in the +leaves are passing in various directions to be used where they are wanted. +When we reflect that these substances are the foods from which everything +in the tree—new cambium, new roots, buds, flowers, and fruit, etc.—are +to be constructed, it becomes clear that if any enemy settles in the +cortex and robs it of these substances, it reduces not only the general +powers of the tree, but also—and this is the point which especially +interests us now—its timber-producing capacity. In the same way, anything +which cuts or injures the continuity of the cortical layers results in +diverting the nutritive substances into other channels. A very large class +of phenomena can be explained if these points are understood, which would +be mysterious, or at least obscure, otherwise.</p> + +<p>Having now sketched the condition of this cortical jacket when the branch +or stem is still young, it will be easy to see broadly what occurs as it +thickens with age.</p> + +<p>In the first place, it is clear that the continuous sheet of cork (C<i>o</i>) +must first be extended, and finally ruptured, by the pressure exerted from +within. It is true, this layer is very elastic and extensible, and +impervious to water or nearly so—in fact, it is a thin layer or skin, +with properties like those of a bottle cork—but even it must give way as +the cylinder goes on expanding, and it cracks and peels off. This would +expose the delicate tissues below, if it were not for the fact that +another layer of cork has by this time begun to form below the one which +is ruptured: a cork-forming layer arises along the line φ and busily +produces another sheet of this protective tissue in a plane more or less +exactly parallel with the one which is becoming cracked. This new +cork-forming tissue behaves as before: the outer cells become cork, the +inner ones add to the green succulent parenchyma cells (<i>pa</i>). As years go +on, and this layer in its turn splits and peels, others are formed further +inward, and if it is remembered that a layer of cork is particularly +impervious to water and air, it is easy to understand that each successive +sheet of cork cuts off all the tissues on its exterior from participation +in the life processes of the plant: consequently we have a gradually +increasing <i>bark</i> proper, formed of the accumulated cork layers and other +dead tissues.</p> + +<p>A great number of interesting points, important in their proper +connections, must be passed over here. Some of these refer to the anatomy +of the various "barks"—the word "bark" being commonly used in commerce to +mean the whole of the cortical jacket—the places of origin of the cork +layer, and the way in which the true bark peels off: those further +interested here may compare the plane, the birch, the Scotch pine, and the +elm, for instance, with the oak. Other facts have reference to the +chemical and other substances found in the cells of the cortex, and which +make "barks" of value commercially. I need only quote the alkaloids in +cinchona, the fibers in the malveceæ, the tannin in the oaks, the coloring +matter in <i>Garcinia</i> (gamboge), the gutta percha from <i>Isonandra</i>, the +ethereal oil of cinnamon, as a few examples in this connection, since our +immediate subject does not admit of a detailed treatment of these +extremely interesting matters.</p> + +<p>The above brief account may suffice to give a general idea of what the +cortical jacket covering our timber is, and how it comes about that in the +normal case the thickening of the cylinder is rendered possible without +exposing the cambium and other delicate tissues: it may also serve to show +why bark is so various in composition and other characters. But it is also +clear that this jacket of coherent bark, bound together by the elastic +sheets of cork, must exert considerable pressure as it reacts on the +softer, living, succulent parts of the cortex, trapped as they are between +the rigid wood +<!--010.png-->cylinder and the bark; and it is easy to convince +ourselves that such is the case. By simply cutting a longitudinal slit +through the cortex, down to near the cambium, but taking care not to +injure the latter, the following results may be obtained. First, the bark +gapes, the raw edges of the wound separating and exposing the tissues +below; next in course of time the raw edges are seen to be healed over +with cork—produced by the conversion of the outer cells into cork cells. +As time passes, provided no external interference occurs, the now rounded +and somewhat swollen cork-covered edges of the wound will be found closing +up again; and sooner or later, depending chiefly on the extent of the +wound and the vigor of the tree, the growing lips of the wound will come +together and unite completely.</p> + +<p>But examination will show that although such a slit wound is so easily +healed over, it has had an effect on the wood. Supposing it has required +three years to heal over, it will be found that the new annual rings of +wood are a little thicker just below the slit; this is simply because the +slit had released the pressure on the cambium. The converse has also been +proved to be true—<i>i.e.</i>, by increasing the pressure on the cambium by +means of iron bands, the annual rings below the bands are thinner and +denser than elsewhere.</p> + +<p>But we have also seen that the cambium is not the only living tissue below +the bark: the cortical parenchyma (<i>pa</i>) and the cells (<i>c</i>) of the inner +cortex (technically the phloem) are all living and capable of growth and +division, as was described above. The release from pressure affects them +also; in fact, the "callus," or cushion of tissue which starts from the +lips of the wound and closes it over, simply consists of the rapidly +growing and dividing cells of this cortex, <i>i.e.</i>, the release from +pressure enables them to more than catch up the enlarging layer of cortex +around the wound.</p> + +<p>An elegant and simple instance of this accelerated growth of the cortex +and cambium when released from the pressure of other tissues is exhibited +in the healing over of the cut ends of a branch, a subject to be dealt +with later on; and the whole practice of propagation by slips or cuttings, +the renewal of the "bark" of cinchonas, and other economic processes, +depend on these matters.</p> + +<p>In anticipation of some points to be explained only if these phenomena are +understood, I may simply remark here that, obviously, if some parasite +attacks the growing lips of the "callus" as it is trying to cover up the +wound, or if the cambium is injured below, the pathological disturbances +thus introduced will modify the result: the importance of this will appear +when we come to examine certain disturbances which depend upon the attacks +of fungi which settle on these wounds before they are properly healed +over. In concluding this brief sketch of a large subject, it may be noted +that, generally speaking, what has been stated of branches, etc., is also +true of roots; and it is easy to see how the nibbling or gnawing of small +animals, the pecking of birds, abrasions, and numerous other things, are +so many causes of such wounds in the forest.</p> + +<div style="text-align: center;">(<i>To be continued.</i>)</div> + +<hr class="ChapterTopRule" /> +<div class="c3"><a name="SIBLEY_COLLEGE_LECTURES_1887-88" id="SIBLEY_COLLEGE_LECTURES_1887-88"></a>SIBLEY COLLEGE LECTURES.—1887-88.</div> + +<div class="c3">BY THE CORNELL UNIVERSITY NON-RESIDENT LECTURERS IN MECHANICAL +ENGINEERING.</div> + +<h2>III.—<span class="smcap">The Evolution of the Modern Mill.</span><a name="FNanchor_3_3" +id="FNanchor_3_3"></a><a href="#Footnote_3_3" class="fnanchor">[3]</a></h2> + +<div class="c3">By <span class="smcap">C. J. H. Woodbury</span>, Boston, Mass.</div> + +<h3>BELT TOWERS.</h3> + +<p>The distribution of power has not always received the judicious treatment +which its importance deserves. There are but few references to this +question in the books on the subject, and these treat of methods that are +not in accordance with the application of the art in its present state.</p> + +<div class="footnote"><p><a name="Footnote_3_3" id="Footnote_3_3"></a><a class="label" href="#FNanchor_3_3">[3]</a> Continued from <span class="smcap">Supplement</span>, No. 647, page 10331. +</p><p> +The lecture was illustrated by about fifty views on the screen, which +cannot be reproduced here, showing photographs of mills and mechanical +drawings of the methods of construction alluded to in the lecture.</p></div> + +<p>The early form of the distribution of power consisted in placing a +vertical shaft extending through the whole mill and distributing the power +at each story by means of beveled gears, generally of skew-beveled form. +The mechanical defects of such a method of distributing power, with regard +to protection, repairs, and necessary care, are readily apparent, and +there have also been many severe accidents caused by the breaking of teeth +in these gears.</p> + +<p>The present method of distributing power in this country is entirely by +lines of belts extending up through what is known as a belt tower, which +constitutes an element of great fire hazard to a mill. In some cases the +belts are carried from story to story, covered by a casing of wood, and in +other instances the tower forms a flue which may be the means of the rapid +spread of fire throughout the building.</p> + +<p>Before the introduction of automatic sprinklers there was not, I believe, +a single instance of a fire entering the lower portion of a belt tower +during working hours without accomplishing the destruction of the mill. +Since the equipment of such places with automatic sprinklers, there have +been several fires of this nature extinguished with nearly nominal damage. +That is to say, the hazard of fire starting in such places is beyond the +capacity of any apparatus other than automatic sprinklers to cope with it.</p> + +<p>It would be impossible to arrange the distribution of power in many mills +to conform to conditions of safety without reorganizing the whole plant, +which would, of course, be impracticable. But in many instances +modifications can be introduced which will diminish the hazard to a great +degree. When the pulleys and belting are covered with sheathing in each +room, the continuity of these flues can be broken by removing this +sheathing down to the height of four or five feet above the floor, so that +the covering will merely constitute a physical protection to any one +approaching the belting.</p> + +<p>The best method of arranging the belt tower has been in the case of a mill +at Fall River, which was erected upon the ruins of a building destroyed by +a fire originating in the belt tower. The machinery is driven by a steam +engine situated in an ell projecting from one side at about the middle of +the mill; and the main belt communicates to pulleys in a stone masonry +<!--011.png-->tower located directly inside the walls of the main mill; and thence, +from pulley to pulley, the power is communicated to each floor by shafting +passing through holes left in the tower, and in no instances by means of +belts.</p> + +<p>There is a separate stairway inside of the tower for lubricating the +journals, etc., and the top of the tower is covered with skylights +protected underneath by a wire netting. In case of a fire in the belt +tower, the heat will readily break the glass at the top, and the fire will +tend to go up and out of the tower rather than through the mill.</p> + +<h3>MILL FLOORS.</h3> + +<p>The questions involved in designing the floors of a mill are of great +importance, contributing in no small measure to elements concerned in the +successful operation of the mill, and to a greater extent to its standing +as a fire risk, and therefore affecting the constant expense of insurance.</p> + +<p>In the case of a building designed merely for sustaining of loads, as in a +storehouse, a floor would naturally be designed on the basis of +considering the breaking strength of the timber. But in the case of a +mill, the limitation is the amount of flexure allowable under the +circumstances; and therefore the floors of the building are made more +nearly rigid than would be required merely from the consideration of the +ultimate strength of the structure.</p> + +<p>The books on the subject, repeating over a constant which was first, I +believe, given by Brunel in testimony before a parliamentary commission, +have held that one four-hundredth of a span is the proper ratio of +flexure. This may have been a very good rule to give to the parliamentary +commission, but it is hardly the practical method of limitation for a +matter of engineering construction, because the flexure of a loaded beam +is in the form of a curve, and therefore its law is that of a curvilinear +function, and not of a straight line. I have examined a great number of +precedents of good construction in this connection, and for mill use have +deduced the formula for deflection in inches, <i>d</i> = 0.0012 L², in which L +is the length of span in feet. It will be readily recognized that the true +constant of deflection of span is measured by the radius of curvature +which will give a uniform and allowable distortion to the floor in either +direction to the limit of the radius upon which this formula is based, +which is 1,250 feet.</p> + +<p>I do not propose to offer to you on this occasion any remarks in regard to +the treatment of the mathematics of the problem of applied mechanics +concerned in the questions of transverse stress, knowing that you have +certainly received instruction upon these subjects. But referring to the +questions of mill floors, I would state that Southern pine beams of solid +timber twelve by fourteen up to fourteen by sixteen inches are used; and +instead of attempting the use of one piece of timber, it is preferable to +use two pieces of the same depth and of half the breadth. These should be +bolted together, with a space of an inch or so between them left by +placing small vertical pieces of wood between the timbers when they are +bolted together. In this manner one is more sure of sound timber, and in +the process of seasoning there is less liability of dry rot in the +interior, or of injurious checking, warping, or twisting.</p> + +<p>The end of the beams should rest upon iron plates in the masonry, and +should be secured by means of a tongue upon the plate entering a groove +across the lower side of the beam. It is not feasible to make this groove +to a close fit with the tongue; but it is cut a great deal larger, and the +whole brought to a firm bearing by means of pairs of wedges or quoins +driven into the groove each side of the iron tongue.</p> + +<p>The outer end of the plate contains ribs or tongues reaching down into the +brickwork. In this manner the timber is securely fastened to the +brickwork; and yet in time of accident or of fire the falling of the beam +in the middle of the mill will raise it up sufficiently so that it will +clear the tongue and fall without tearing the wall down, which is the case +whenever the beams are secured by bolts entering the end of the beam from +the face of the wall.</p> + +<p>At the points of support in a line of columns, the beams should be free +from all compressive stress, transmitted through the lines of columns from +floors above, by means of iron pintles between the cap of one column and +the floor of the next one carrying this load.</p> + +<p>A faulty method of construction, quite frequently used, consists in +covering each column with a bolster of timber, four or five feet long, +reaching out under the floor beams.</p> + +<p>The transverse contraction of wood in seasoning after it is in position in +the mill varies from three-eighths of an inch to double that quantity per +foot; and the aggregation of such shrinkage amounts to a very considerable +distortion or settling of the floor in a mill of several stories. +Moreover, the resistance of timber to transverse crushing has been shown +by experiments on the testing machine at the United States arsenal at +Watertown to be about three times the resistance to longitudinal crushing.</p> + +<p>Iron columns for mills have been entirely displaced by those of timber, as +it was found that the latter were more reliable in resistance to fire, +were freer from defects in construction, and possessed less tendency to +vibration. A series of tests on full-sized mill columns of various forms +of construction and age, made in the experiments referred to, at the +Watertown arsenal, showed that resistance to crushing of Southern pine +columns was about 4,500 pounds to the square inch, and remarkably uniform +as to the different results. In white oak there was a wider range, owing +to the difference in the grain of the various samples, the generality of +the specimens being of somewhat less resistance than that of Southern +pine.</p> + +<p>It was furthermore found by these experiments, on comparing the crushing +resistance of a full-sized column with that of a portion of the same, +perhaps two feet in length, that the results were practically identical, +likewise that within the limits of construction used for these columns the +question of flexure did not enter at all in the problem, but they gave way +by direct crushing, and that the resistance to crushing was proportional +to its load upon the minimum cross section.</p> + +<p>The precedents of safe construction in this matter show that wood columns +in mills have successfully sustained for many years a load of six hundred +pounds to +<!--012.png--><span class="pagenum"><a name="Page_10347" id="Page_10347">10347</a></span>the +square inch without deterioration. As the resistance of +such columns is proportional to the cross section, the results of these +experiments have changed the practice of mill engineers in the matter; and +square columns are of almost universal use, which interfere with no +greater area on the floor than the round column of the same diameter, +while they furnish an increased resistance of a little over twenty per +cent. in excess.</p> + +<p>Along the axis of such columns a hole of about one and one-half inches in +diameter is bored, and near each end a couple of transverse holes, +generally half an inch in diameter, furnish means of ventilating the +inside of the column for the prevention of dry rot and also checking, due +to contraction and seasoning.</p> + +<p>There are several methods of laying the floor plank upon these beams, +which are placed from eight to ten feet apart, according to the dimensions +of the machinery to be placed in the mill. The first floor of three-inch +plank, planed on one side and grooved on both edges, is laid planed side +down, and the hardwood splines are inserted into the grooves before the +planks are pressed up and spiked to the beams. An agreeable finish is +sometimes arranged underneath by plowing a rabbet in each of the corners, +and inserting a bead in the groove thus formed, which is secured by nails +driven diagonally into the plank on one side only, because if the nails +were driven into both sides, the bead would be split by the contraction of +the plank.</p> + +<p>These planks should be cut to sufficient length to cover two bays of the +mill; and their transverse resistance is that of a beam fixed at one end +and supported at the other, or one and three-fifths as much as a plank of +the same size but half the length would support; but it should be +remembered in this connection that, if evenly distributed on the floor, +five-eighths of the load would be carried by every alternate beam unless +the planks are so laid to break joints at convenient intervals of about +three feet.</p> + +<p>The top flooring is generally laid directly upon the floor plank, with one +or two thicknesses of roofing paper interposed; but the preferable method, +which deadens the sound and vibration, and also greatly increases the +fire-resisting qualities of the structure, is to lay a coat of mortar on +the floor plank, preserving the uniform thickness by means of furring +placed about sixteen inches apart, and then to lay the upper floor upon +this.</p> + +<p>For these upper floors hardwood plank, one and one-fourth inches thick, +and not over four inches wide, is used. The black birch is considered by +many to possess the greater resistance to wear; and Southern pine is +ranked next, although the latter wood gives trouble by stringing, +especially when trucks are rolled over it. White maple forms an excellent +top floor, although not so hard as others, especially where the floor is +likely to be exposed to water, as in paper mills and bleacheries.</p> + +<h3>ROOFS.</h3> + +<p>Benjamin Franklin once said that next to a good foundation a good roof was +the most important feature of a building. Although the constructive +features of mill roofs are well defined, yet with regard to roof covering +there is a wide diversity of experience and opinion.</p> + +<p>The present form of factory roofing resembles a floor in its construction, +being made, in a similar manner, of plank laid upon beams which project +through the walls, where they act as a bracket to the cornice, the ends +being sawed after any suitable ornamentation. The inclination for such +roofs is about three-fourths of an inch to the foot. Where a mill is +narrow enough for a single beam to reach from the wall to the ridge, they +form cantilevers, the second point of support from the wall being by the +columns one-third of the distance across the mill, and the ends of the +beams are further secured together by means of iron dogs. For mills of +greater width, the beam would reach only to the row of columns, and over +the middle of the mill a beam is placed, usually horizontal on the under +side, and hewn down from the middle to each end, so as to preserve the +same slope on the upper side of the beam as for the roof.</p> + +<p>In many instances mills are built with brick cornices, without any of the +wood projection from the side; and in other buildings the walls are +carried above the roof, which slopes toward the center, and all water +falling on it or melted from the snow is conducted from it by pipes +leading down through the middle of the mill.</p> + +<p>It is not desirable to place gutters around the edge of the mill, as they +serve no useful purpose, and are in continual need of repairs. By leaving +the edge of the mill plank square and protecting it by sheet metal +flashing, the rain falling from the roof can be received by a concave walk +of coal tar concrete placed on the ground around the building. Suitable +porches over doors, or some guard on the roof at these points, will +prevent people who may be passing in at doors from being unduly wet by +water from the roof.</p> + +<p>There are numerous forms of roof coverings, the use of the different +varieties being to a great extent local; that is, the sheet iron coverings +used in the Middle States are almost unknown in New England; and in the +latter place the ordinary tinned iron roofing is universally painted, +while in the Dominion of Canada it is laid obliquely and never painted.</p> + +<p>It is conceded by all that sheet copper forms the most desirable method of +covering a roof; and, if one could be assured of the permanence of the +structure, irrespective of the necessity for making changes every half +year in order to keep pace with the march of invention, it would doubtless +be shown that under such conditions of permanency copper would form the +cheapest roof.</p> + +<p>The most widely used roofing materials for this class of buildings are the +asphalt and the coal tar roof, the latter being the most widely used in +New England. There are numerous varieties of these composition coverings, +which are applied by various methods. Some of these are of the most +satisfactory character, while others are poorly designed and unskillfully +applied, and are a constant source of trouble and expense to the occupant +of the building.</p> + +<p>One of the leading manufacturers, the efficiency of whose work for many +years over a large amount of mill property I can vouch for by personal +knowledge, uses the following method of applying the roofing. Three layers +of roofing felt are placed on the plank parallel to the eaves, and +continued by lapping each additional layer two thirds of its width upon +the preceding one, +<!--013.png-->and in this manner covering the roof with three +thicknesses of the felt, breaking joints. This is secured to the roof by +nails through tin washers and coated with a melted composition, and then +two additional layers of felt are placed over the whole. Another coat of +composition is then applied and gravel is placed over the whole while +soft.</p> + +<p>This maker does not approve of the practice of cementing each sheet of +felt when it is laid, because it does not allow the felt freedom to yield +from the expansion and contraction of the roof. When tin is applied to +roofs, resin-sized building paper should first be laid on the roof plank, +and the sheets of tin should be painted on the lower side before being +laid.</p> + +<p>Of late years cotton duck has been applied as a roof covering, and has +been watched with a great deal of anticipation, although it has been used +for similar purposes in covering ships' decks for many years. But the two +uses are not strictly comparable, because the ship's deck is calked tight, +and therefore the covering is free from the application of moisture +underneath, while the roof is never tight, and the warm air underneath, +heavily charged with moisture, which permeates the cracks between the +planks, becomes chilled and condenses as it nears the top, carrying on a +process of distillation.</p> + +<p>As an example of the extent to which this can be carried on, I have known +of instances where people presumed they were making a good roof by leaving +slight air spaces by means of the furring laid between the roof plank and +the top boarding. The circulation of air in these spaces deposited +sufficient moisture to rot the boards.</p> + +<p>A mill manager, wishing to have a roof over a very warm room, which should +be both tight and a very perfect non-conductor, made a roof containing a +space of about sixteen inches, which was filled with sawdust, and the roof +boarding on top of this was covered with tar and gravel in the usual +manner. In a few weeks the water began to drip through the ceiling as if +the roof was leaking, although there was no snow on the top of the roof. +Investigation showed that within that short time a sufficient amount of +water had condensed with the sawdust to saturate the whole.</p> + +<p>I would say in this connection that three inches of plank afford an ample +protection against condensation over any ordinary process of manufacture, +although four inches of plank have been used as a roof over paper machines +in order to be safe beyond peradventure; but it is necessary that nails +should not be driven into the bottom of this roof plank, because the point +of a nail will reach to a lower temperature near the outside of the roof +in the winter, and being a better conductor, it will cause moisture to +condense upon the head of the nail.</p> + +<p>Tin roofing is so general in use as not to require any allusion to methods +of application, but the only course to reach economical and satisfactory +results for a term of years, especially for locations near to the sea +shore, is to use the best quality of dipped roofing plates of some brand +which can be relied on as conforming to the standard and free from +"wasters" or imperfect plates.</p> + +<p>Duck roofing has been successfully applied by first laying and tacking +down a covering of two-ply asphalt paper, and upon this was spread a +covering of resin-sized sheathing paper, tacked in the usual manner. Upon +this was laid a covering consisting of cotton duck, forty-four inches wide +and weighing twenty-six ounces to the yard. Several methods of joining the +edges of the duck together have been tried, resulting in the abandonment +of the method of sewing used, for the preferable method of nailing the +duck down, laying one strip over the other, and then opening the duck, a +lock joint is formed without any jointure between the two sheets exposed +to the weather. After the duck is stretched on the roof, it is securely +fastened by means of round-headed woodscrews, one and one-fourth inches +long, through a concave tin washer three-fourths of an inch in diameter, +resting upon a seven-eighths of an inch washer made of roofing felt.</p> + +<p>A coat of hot pine tar with a small quantity of linseed oil is laid upon +the whole of the duck roofing, after being laid, for the purpose of +filling the fiber and preserving the cotton fabric by means of the +antiseptic principles of the pine tar. The surface is then covered with +two coats of mineral paint.</p> + +<p>Within a year, paper has been very successfully used as a roof covering. +Sheets of wood pulp board about one-sixteenth of an inch in thickness are +treated by a process which renders them hard and elastic, and secured upon +the roof by means of tacks through concave tin washers. The edge of each +sheet is grooved, in order to allow for the expansion and contraction of +the roof. The whole roof is then covered with a heavy mineral paint. +Experience with this during the past severe winter in Maine has been of +the most satisfactory nature.</p> + +<p>Shingles furnish a much better roof covering than slate, both in the +matter of conduction of heat or cold in the extremes of summer and winter +and also in resistance to fire. The heat of a slight fire underneath the +roof will cause slates to crumble; and the same result will be obtained by +heavy sparks falling and burning upon the roof. Some people treat shingles +by boiling them under pressure in a solution of salt and chloride of lime, +for the purpose of antiseptic treatment and also to render them fireproof.</p> + +<h3>STOREHOUSES.</h3> + +<p>The latest form of storehouses tends to one of two extremes. Where land is +nearly level, and cheap, the greatest storage capacity can be obtained +with the greatest economy by means of a one or two story storehouse built +with a plank construction, with the beams secured to the posts by means of +knees. A traveling crane or railroad runs along the middle of the +storehouse, affording a ready means for rapid changes of the contents of +the storehouse.</p> + +<p>Another form for storage is by means of very large brick buildings, +especially arranged as a protection against outside fire. In designing a +storehouse it is of especial importance that the stories should not be +made so high that it will be possible for a dangerous load to be piled +upon any one floor.</p> + +<p>The wool storehouse of the Pacific Mills at Lawrence can be safely said to +be in its design and construction the finest example of mill engineering +in the country.</p> + +<p>Another type of mill storehouse, designed for both raw material and +finished goods, is designed by Mr. John Kilburn, of Lowell, and consists +of two buildings +<!--014.png-->placed at right angles to each other, and joining only +at one corner. These buildings do not contain openings through the floors +of any nature whatsoever, either for stairways, elevators, or any other +purpose; but all vertical communication is furnished by means of a masonry +tower at one corner of the buildings, which contains an elevator and +stairway. At the level of each floor, substantial balconies lead through a +doorway in the tower to one in the storehouse, and the storage is added to +or withdrawn from the storehouse in this manner.</p> + +<p>I have not made any reference to the use of rolled iron for structural +purposes, because such material has not been used to any extent in mill +architecture. Irrespective of questions of space or of strength, wood +beams possess advantages in the reduction of vibration, facility of +securing the plank above and hangers below, and a great many other +purposes in the changing and alterations of a mill, which render them +peculiarly useful, and I believe that the results with Southern pine beams +in American mills are much superior to those of the iron beams in European +mills.</p> + +<p>No small part of the success attending the use of rolled iron in the +structural purposes for which it is adapted, has been due to the excellent +and reliable engineering information contained in the manuals and +catalogues issued by the rolling mills. Such works are reliable and clear, +and, as far as I know, can without exception be safely followed.</p> + +<p>The general tendency of American mill construction is toward as low +buildings as the price of land will admit. The American mills being +devoted to a large variety of operations, instead of being confined to a +single process after the manner of those of European type, require a great +deal more care in their organization, not merely in the original lay-out +for the purpose of arranging for the passage of the stock in processes +from the raw material to the finished product in as straight lines as +possible, but due consideration should also be given to providing +facilities for the enlargement of the mill.</p> + +<p>As an illustration of the methods employed, in a paper mill plan of my own +design, [the view and plan being thrown on the screen], the various +operations containing processes of different hazard in regard to fire are +completely isolated from each other by means of fire walls, and the +storage of the mill is in turn isolated from the manufactory.</p> + +<p>The storehouse consists of three sections, the largest section for paper +stock, which is sorted in the upper story, the second section, one story +in height, for other manufacturing supplies, and beyond the fire wall the +storehouse is arranged to contain the finished paper. Goods can be taken +away from or added to the storehouse at the single line of teams, or +railroad siding.</p> + +<p>After the stock leaves the sorting room, it is carried to the dusting room +over a covered bridge, which is protected from the weather on one side, +yet does not form a flue for the spread of fire as does a closed bridge.</p> + +<p>The first room in the main mill is used for a dusting room, and thence the +stock falls into the rotary bleach, whence it is carried through the fire +doors to the engine room. Here it meets the wood pulp and clay wheeled +from the middle section of the storehouse, which is on that same level. +After washing and beating, the stock is run into the drainers below, +whence it is raised again, and after suitable intermediate processes the +pulp is converted into paper on the paper machine in the connecting +building. This paper is then taken into the upper part of the main +building, and after being dried on the lofts is suitably calendered and +packed before being transferred into the extreme end of the storehouse to +await shipment.</p> + +<p>At the present time it has been found that an inclined roof of the olden +type is not a necessity over a paper machine, as has been decreed by the +tradition passed down from old practices. Within the last year, a number +of flat roofs have been placed over paper machines, without any trouble +ensuing from condensed water forming on the ceiling and thence dropping +upon the stock. It is well known that the use of a flat roof in such +places is attended with a great many mechanical conveniences; and the +pitched roof hitherto used for these purposes has been submitted to, only +because it was presumed to be necessary. The whole tendency of mill design +is in the line of fitness of means to ends, in the simplest and most +direct manner.</p> + +<p>When the mills in Lowell were first built, they consisted of isolated +buildings, which it was presumed would remain for all time; but when it +became necessary to increase the plant, it was found that the engineer had +wisely laid out the mills in the same yard in reference to a fixed grade, +so that corresponding floors would meet when the buildings were extended +so that they reached each other.</p> + +<p>Wherever a strong and diffused light is necessary for any manufacturing +process, or the conditions are such as to require unusual stability of the +building, one-story mills lighted by monitors afford accommodations not +reached by any other form of construction.</p> + +<p>In presenting before you some of the salient features of modern mill +construction, I have endeavored to show the various steps of progress +leading up to the development of the present types of design, as well as +some of the methods of construction in present use.</p> + +<p>These various steps in advance, producing mills better suited for the +purposes for which a mill is built, are not generally due to elements +originating with the manufacturers, but with the Factory Mutual +Underwriters, who, finding it cheaper to prevent a fire than to settle a +loss, have in every manner encouraged improvements in construction, +equipment, and administration, with the result of diminishing the +insurance on textile manufacturing property during the last generation +from two and one-half down to one-fourth of one per cent., or reducing the +cost of insurance eighty per cent.</p> + +<p>In designing any work, a careful regard should be given to precedents, +remembering that a good designer must also be a good copyist.</p> + +<hr style="width: 45%;" /> + +<p><span class="smcap"><a name="The_Passive_State_of_Iron_and_Nickel" id="The_Passive_State_of_Iron_and_Nickel">The Passive State of Iron and Nickel.</a></span>—E. Saint Edme.—The nickel of +commerce immediately becomes passive if immersed in ordinary nitric acid. +Iron, while being briskly attacked by common nitric acid, is rendered +passive by contact with nickel. If steel and nickel are plunged into the +acid together, the former metal is not even momentarily attacked. Nickel +retains energetically a proportion of combined nitrogen, to which its +passivity is +due.<!--015.png--><span class="pagenum"><a name="Page_10348" id="Page_10348">10348</a></span></p> + +<hr class="ChapterTopRule" /> + +<h2><a name="IMPROVED_TORPEDO_BOAT" id="IMPROVED_TORPEDO_BOAT"></a>IMPROVED TORPEDO BOAT.</h2> + +<p>We give an illustration of the new type of second class torpedo boat which +Messrs. Yarrow & Co. have recently constructed to the order of the +Admiralty, and which was tried at the latter part of last year. The boat +is 60 ft. long over all and 8 ft. 6 in. wide, 3 ft. shorter and from a +foot to 15 in. wider than the old type of second class boats. She attained +a speed of rather more than 17 knots per hour on her official trial with 4 +tons on board. The speed, when light, for six runs on the measured mile +was 18½ knots. The latter seems a very high speed for so small a vessel, +and indeed it is a remarkable performance, but at the same time the speed +of 17.031 knots on a four hours' trial with 4 tons on board is more +remarkable still. It is well to note, says <i>Engineering</i>, in comparing +speeds of torpedo boats, under what conditions as to weight carried and +duration of running the trial is made. In our previous notice we referred +to the manner in which this boat differs from ordinary second class boats +in the manner of ejecting the torpedo; and the arrangement is well shown +in the engraving. The more ordinary method of firing the torpedo from a +tube or tubes, built into the hull and pointing forward through the bow, +will be familiar to the majority of our readers; but here it will be seen +the bow fire has been altogether abandoned, and a swiveling gun placed aft +is substituted. The gun, of course, is not new; indeed, one was placed on +the old Lightning, the first torpedo boat built for the English navy. That +vessel was, however, a first class boat, and although not so large as the +first class boats now built, was considerably bigger than No. 50, which is +the official designation of the craft under notice. In the Lightning, too, +the torpedo gun was placed forward, and was trained in quite a different +manner to that of this second class boat. We have already commented on the +offensive advantages of being able to eject the torpedo through a wide +angle of range, and when going at speed, rather than having to bring the +boat to a stop and fire only end on. We need not therefore recur to this +point; but since our former notice appeared we have had, while on shore, +an opportunity of seeing the boat steam at speed and maneuver. Our +previous experience was obtained on board—a position which, in some +respects, does not afford so good a point of observation as when one is at +some little distance from the boat. It is certainly a remarkable sight to +see the manner in which this little vessel winds among craft or round +buoys, or turns circles of surprisingly small diameter. She seems to pivot +on a point very near the bow, a fact which is no doubt chiefly to be +accounted for by the way the deadwood is cut away aft. This allows the +stream of water diverted by the unusually large rudder to swing the after +part round with facility.</p> + +<div class="figcenter" style="width: 700px;"> +<img src="images/i015.jpg" width="700" height="295" alt="Craft underway." title="" /> +<span class="caption">IMPROVED TORPEDO BOAT.</span> +</div> + +<p>Another notable feature about No. 50 is the comparatively small bow wave +she throws up. We believe it is pretty generally acknowledged now that the +most noticeable point at night about a torpedo boat traveling at high +speed—putting on one side flame and sparks from the funnel—is the high +bow wave the majority of these vessels throw up when going quickly through +the water. The powerful electric search light causes this mass of foaming +water to show up with peculiar distinctness against the dark background of +sea and sky. It has been, therefore, thought advisable to reduce this +undesirable feature even if something in the shape of speed has to be +sacrificed. Fairly full bow lines are the best for fast boats of this +class, but in such a model the big bow wave is very noticeable. Messrs. +Yarrow have met the demand of naval officers for a less easily observed +boat by placing the greatest cross section further aft than they would +have done had speed alone been the point aimed at, as it almost always was +in the earlier torpedo boats. It is therefore additionally creditable to +Messrs. Yarrow that they have reached the unprecedentedly high speed of +seventeen knots, with so considerable an addition to the beam, and that +they have at the same time reduced the bow wave.</p> + +<p>There is a further advantage of less surface disturbance when running +torpedo boats. It is unnecessary to point out that surprise will be the +chief element of success in future possible attacks in which these craft +may be engaged. As the bow wave is most likely to reveal the presence of +the boat by sight, so also will it most probably give first warning of +approach by sound. It is the splash of the water and not the noise of the +machinery that can be heard for the greatest distance when a boat is +running with hatches closed—speaking of course of high-speed boats in +which the engines are +<!--016.png-->kept to a high degree of perfection, as they should +be, and in the Royal Navy are, with all torpedo boats. It will therefore +be seen that there is an additional reason for reducing the objectionable +bow wave.</p> + +<p>The boat which we illustrate recently made the run from the Thames to +Portsmouth, and, the weather being bad, was taken through the somewhat +intricate but more sheltered fairways and channels of what is known as the +"overland passage." Off Margate she managed to get on the ground—a result +by no means to be wondered at; and, as the sands here are very hard, she +smashed her propeller. After a time she was got off and beached, when a +new propeller was fitted. We mention this incident, as it is generally +supposed that these craft are of a very fragile description; "egg shell" +is the favorite term of comparison. One distinguished naval +officer—retired—has said he would never willingly go on board these +craft, for fear of putting his foot through the bottom; and there is a +very funny story extant about a sailor with a wooden leg. It would seem, +however, from the experience of No. 50, that steel vessels are of much +more robust constitution than is generally supposed, and, indeed, there is +ample testimony to the fact. We recently witnessed the efforts of a small +working party to get one of these vessels over a bank. She was pushed as +high up as the strength of the party would allow, and in this position her +fore part was over the bank for about a third of the length of the boat. A +tackle was then put on the bow, which was bowsed down until the boat could +be dragged straight ahead.</p> + +<p>A few words may appropriately be added here as to torpedo boat policy +generally. Admiral Colomb, in the opening remarks of his excellent little +manual, "The Naval Year Book," refers to the torpedo boat question in the +following terms: "The fleet, the flotilla, the cruiser, and the harbor +attack and defense have each had (<i>i. e.</i>, during the past year) their +share of attention, and developed exercise, and opinion has been advanced, +guided, or turned back by the observation of facts which these exercises +have brought out. While it cannot, perhaps, be said that the torpedo, as +torpedo, has much altered its position in naval estimation, it seems fair +to assume that the torpedo boat, as boat, has fallen in repute. In the +first, it has grown very much larger, and has, in point of fact, ceased to +be a boat. In part this may have come about because the <i>role</i> which some +proposed for the torpedo boat, of being an entirely defensive weapon +confined to territorial localities, and operating only within a short +distance from its port, has never been generally accepted. Boats which +were never intended for voyages have been sent on voyages, and, being +found more or less unsuited for that kind of service, supposed +improvements have been made, so that they should be capable of executing +it. The 'harbor defense' instrument has become a 'sea attack' instrument, +and in some sense an unrecognized rival to the undoubted sea-going torpedo +vessels like the Archer, the Fearless, and the Rattlesnake."</p> + +<p>In these passages Admiral Colomb has put the present aspect of the torpedo +boat question very aptly. We are now experiencing the inevitable reaction +consequent upon our early over-valuing of the torpedo. The unknown +possibilities for distinction of those weapons were so magnified that +scarcely any expenditure was thought too great to provide means for their +employment, both in and out of season. Torpedo vessels have been growing +in size and costliness. More and more gear has been crowded into them, +increasing their weight and cost, and also the intricacy of their +machinery. In all this, cheapness, the one great virtue of the torpedo, +has been overshadowed. No doubt it is right for a great naval power like +Great Britain to have vessels of all classes, and the possible value of +small fast vessels such as the Archer or the Rattlesnake—not necessarily +as connected with the torpedo—can hardly be overestimated. But for +smaller naval powers, that look on the torpedo boat as a means of coast +defense, especially those countries having a broken coast line studded +with islands, bays, and inlets, it is very questionable whether the +smaller boats, such as that now under notice, will not be a better +investment than the larger craft at present more in vogue. By the +additional seaworthiness of this boat, secured chiefly by the increased +width, the 60 ft., or second class, boat has been lifted into the category +of practicable vessels; and it must be remembered that four or five of +these smaller craft can be purchased for the price of one modern first +class boat. This is the crucial point, the money standard, and it is to +that that all ship and boat building questions must be reduced, +<!--017.png-->whether +it be in wealthy England or the most impecunious and perhaps hardly more +than half-civilized state.</p> + +<p>The question may be argued from many points of view, and we put forward +these remarks simply as suggestions, without any wish to dogmatize. But it +seems that, as the cheaper second class boat has been carried so many +steps in advance, it may be worth while to reconsider the position with a +view to returning to the original torpedo boat idea of small, inexpensive +vessels, acting by surprise; and not putting too many eggs in one basket.</p> + +<hr class="ChapterTopRule" /> + +<h2><a name="SCIENTIFIC_APPARATUS_AT_THE_MANCHESTER_ROYAL_JUBILEE_EXHIBITION" id="SCIENTIFIC_APPARATUS_AT_THE_MANCHESTER_ROYAL_JUBILEE_EXHIBITION"></a>SCIENTIFIC APPARATUS AT THE MANCHESTER ROYAL JUBILEE EXHIBITION.</h2> + +<p><i>Sine and Tangent Galvanometer.</i>—An exhibit of original scientific +apparatus was contributed by Prof. G. F. Fitzgerald, of Trinity College, +Dublin. The first instrument was a sine and tangent galvanometer, which +combines both instruments, and has four interesting peculiarities: (1) The +windings of the coils are visible through the plate glass sides, so as to +be capable of easy measurement <i>in situ</i>. (2) The position of the needle +is read by reflections of a cylindrical scale in two rectangular mirrors +whose intersection is horizontal, and which are attached to the magnet. +These mirrors reflect images of opposite sides of the scale to a fixed +mirror which reflects them into a microscope, in which, by means of a +micrometer, it is possible to read accurately the position of the line +which is the same in the two images. (3) This cylindrical scale is affixed +to the base of the instrument, and the coils can be rotated round it, so +that when the instrument is used as a sine galvanometer its position is +read by reflection in the rectangular mirrors attached to the magnet of a +pointer attached to the coils. (4) By a slight modification of the +suspension, a beam of light can be reflected from a mirror connected to +the magnet at 45° to its axis of rotation, and can emerge through the +plate glass side of the instrument and fall on a horizontal scale, where +it will measure the tangent of the deviation instead of the tangent of +twice the deviation, as in ordinary reflecting galvanometers.</p> + +<p>The meldometer shown is an instrument for facilitating the identification of +small quantities of minerals by comparative observations on their melting +points, and for observing the phenomena of their fusion and ebullition. It +consists of a strip of platinum arranged to traverse the stage of a +microscope, and heated by a current derived from two Grove's cells.</p> + +<p>On this strip the fragments of the mineral, or, if for comparative +observation, of two or more minerals, are placed. The temperature of the +platinum is then raised by gradually diminishing a resistance placed in +circuit with the battery and meldometer, the behavior of the substance +being meanwhile observed through the microscope. To effect the elevation +of a temperature automatically, a resistance, consisting of a rod of +carbon fitted in a vertical glass tube, is employed. Professor Fitzgerald +showed two sets of apparatus for measuring the densities of gases. Both +methods depend on the determination of the amount by which a body is +buoyed up when immersed in the gas.</p> + +<p><i>Model for Illustrating the Properties of the Ether.</i>—A very interesting +exhibit was the model for illustrating the electromagnetic and +luminiferous properties of the ether, of which a detailed description is +almost necessary. The model consists of a series of wheels, rotating on +axes fixed perpendicularly in a plane board, and connected together by +India-rubber bands. The axes are fixed at the intersections of two systems +of perpendicular lines, and each wheel is connected with each of its four +neighbors by an India-rubber band. Thus all the wheels can rotate without +any consequent straining of the system if they all rotate at the same +rate. If, however, some of the wheels are rotated through a different +angle from others, the India-rubber bands will be strained. If it be +desired to represent a region in which conducting matter exists, it will +be represented by removing the bands from a set of wheels. Suppose the +bands are removed from the regions, A and B, and from the connecting line, +A B, then we can represent the charging of these regions with opposite +electricities by introducing some mechanism by means of which the wheels +on opposite sides of the line, A B, can be rotated in opposite directions. +The model is not intended to illustrate in any way the connection between +the ether and matter; indeed, one of the advantages claimed for the model +is, that the study of it so distinctly emphasizes the distinction between +the phenomena depending on the general properties of the ether by itself +and +<!--018.png--><span class="pagenum"><a name="Page_10349" id="Page_10349">10349</a></span>those +depending on its connection with matter. For instance, from the +very case we have just considered, we get impressed upon us that it is by +means of matter only that we can get a hold on the ether so as to strain +it. As the object is not to illustrate the connection between matter and +ether, any rough method of turning the wheels so as to create the proper +strain will do well enough, as it is not the method of producing, but the +nature of the strain produced that is to be considered. Having once +rotated these wheels, we may replace the bands along the line, A B, and we +have the state of the ether between two oppositely electrified bodies +represented on the model.</p> + +<p>It will be observed that half the India-rubber bands are strained, and +that in lines running round the bodies the tight side of a band is always +away from one body and next the other. This represents the polarization of +the ether. The late Prof. Clerk-Maxwell defined polarization as a state in +which the opposite sides of each element are in opposite states. Now, the +opposite sides of each band are in opposite states—one side loose, the +other tight; and so it can very well represent the polarized state of the +ether. The displacement producing the polarization is due to the different +rotation of the wheels carrying the band causing more of the band to be at +one side of the wheels than at the other—less at the tight and more at +the loose side of the pair of wheels, and this represents the electric +displacement producing the polarization. The direction of this +displacement is at right angles to the line of the bands that are +strained, and is out from one body and in toward the other all round.</p> + +<p>Considering the other properties of the ether that are represented by the +model, we observe in the first place that during the time polarization is +taking place the wheels are rotating, and that the rate of rotation of the +wheels is proportional to the rate of increase of polarization, and that +the direction of the axis of rotation is perpendicular to the direction of +the displacement. Hence it is seen that the magnetic force is properly +represented by the rate of rotation of the wheels, and its direction by +the axis of rotation. The model, although simple in construction, is very +useful, and its careful study will greatly assist the student in obtaining +definite physical conceptions of many of the more abstruse phenomena +depending on the ether.</p> + +<p><i>Prismatic Photometers.</i>—Another exhibit was a photometer made of solid +paraffin, or any other translucent substance, invented by Mr. J. Joly, of +the University of Dublin. The arrangement is at once simple and effective. +The instrument depends upon the fact that if a prism be cut from a +translucent body, and so exposed to a source of light that one only of its +faces is illuminated, the light diffused through the substance and +reflected out through the illuminated faces of the prism gives it an +appearance as if lighted up internally. The effect is, in fact, as if the +prism itself was a source of light. Two such prisms laid together on +smooth faces, and receiving light from separate sources, if placed so as +to be at opposite sides of the plane of division, appear as if each was +emitting light proportional in intensity to the source of its supply. The +double prism has the appearance of two luminous bodies laid side by side.</p> + +<p>When, however, the supply to each prism is brought to equality, they +appear as if emitting equal quantities of light; and it is hard to detect +any longer that two prisms are being observed, so completely does all +trace of the plane of division disappear. An ingenious piece of apparatus +invented by Mr. Joly was one for carrying out his method of determining +the specific gravity of small quantities of dense or porous bodies. The +method here shown enables the specific gravity to be determined whatever +the density or state of aggregation of the substances, and in extremely +minute quantities, with an accuracy limited only by the sensitiveness of +the chemical balance.</p> + +<p><i>Telegraphing the Readings of Scientific Instruments.</i>—Another invention +of Mr. Joly was his apparatus for obtaining telegraphically the readings +of meteorological instruments placed at a distance from the observer. This +apparatus may be attached or adapted to the various thermometers, the +barometer, rain gauge, and to other instruments placed in a mountain +station, thus enabling their readings to be taken from a conveniently +placed observatory. Any number of instruments may be worked with perfect +reliability and certainty by the use of three wires only; the only extra +piece of apparatus needed being a disk, carrying insulated contact pieces +arranged round its circumference, to which the wires of the different +instruments are attached. Of these three wires, one serves to put one +after the other of the contacts into circuit with the home station through +the second wire. By this second wire the readings are taken and the +readjustment of the instruments effected. The third wire is for the +indication of the contacts, and is taken from all the instruments to the +galvanometer in the home station.—<i>Industries.</i></p> + +<hr class="ChapterTopRule" /> + +<h2><a name="COLORED_PHOTOGRAPHY" id="COLORED_PHOTOGRAPHY"></a>COLORED PHOTOGRAPHY.</h2> + +<p>About nine months since we directed attention to the system of colored +photography invented by Mr. J. E. Mayall, London. Since that time, Mr. +Mayall has further developed the details of his process, and as a result +his color pictures have been much improved both as regards appearance and +size, and are beautiful specimens of this new departure in photographic +art. As stated in our previous notice, Mr. Mayall, after fourteen years of +experimental research, has discovered the art of reproducing the colors +latent in the negative of the photograph, having arrived at his discovery +by the aid of spectrum analysis, which led him to the conclusion that +every color in the organic world, when exposed to a suitable photographic +plane in a camera, registers exact vibrations. Mr. Mayall has succeeded in +producing chemical colors extremely attenuated, which exactly correspond +with the vibrations in the negative. In doing this, he keeps the film +alive to the smallest vibrations of light. He uses, first, lactate of iron +to impregnate the isinglass film with a salt of iron capable of uniting +with any stronger organic acid; and, secondly, meconic acid, which +impregnates the film of albumen, and has a stronger affinity for iron than +lactic acid. It unites with the iron, and forms a red film, which is in a +state to receive all the lower vibrations of the red end of the spectrum, +and this gives these lower vibrations a fair chance with the electric +light. All subsequent processes assist this chemical march to the +<!--019.png-->final +end of making a print that will take up colors, which, when added, fall in +their places, and there remain indelible and unalterable.—<i>Iron.</i></p> + +<hr class="ChapterTopRule" /> + +<h2><a name="FUTURE_PROSPECTS_FOR_GAS_COMPANIES4" id="FUTURE_PROSPECTS_FOR_GAS_COMPANIES4"></a>FUTURE PROSPECTS FOR GAS COMPANIES.<a name="FNanchor_4_4" +id="FNanchor_4_4"></a><a href="#Footnote_4_4" class="fnanchor">[4]</a></h2> + +<div class="c3">By Mr. <span class="smcap">Thos. Wood</span>, of Sandusky.</div> + +<p>Those who were in attendance at our Dayton meeting will perhaps recall the +fact that the writer, in a paper read at that time, strongly advocated gas +companies taking hold of the electric light business and running the same +in connection with their gas business; you will also recall the fact that +the writer suggested that gas companies should take up the incandescent +electric light and fuel gas. Since that time it has been demonstrated by +several gas companies in this and other States that the electric arc +system can be added with success, financially, to gas companies and with +satisfaction to their patrons; and the writer derives great pleasure in +hearing of so many companies who have left the narrow and beaten track of +prejudice and are now walking in the broad road of progression.</p> + +<div class="footnote"><p><a name="Footnote_4_4" id="Footnote_4_4"></a><a class="label" href="#FNanchor_4_4">[4]</a> A paper read lately before the Ohio Gas Light Association.</p></div> + +<p>It is not my intention to dwell upon arc lighting now only long enough to +state that, after two years of practical experience with the combination, +our company consider they have taken a right step in adopting it, and that +it is satisfactory in every respect. Other gas companies that have adopted +the arc system can undoubtedly corroborate this with their experience. I +would make this paper a continuation of the last one by now taking up the +incandescent electric system and fuel gas question. That both will be +introduced into every city in the United States before long by some one I +have not a shadow of a doubt; and why? Simply because they are both +desirable commodities in domestic economy and hygiene.</p> + +<p>Please lay aside all prejudice, and I will show you an ideal domestic +burner for illumination purposes. Now, what comprises an ideal burner for +domestic use? In the first place, such a burner must not blacken our walls +and ceilings, neither must it give off deleterious products of combustion; +it must be a steady light, and not subject to draughts; it must not give +out heat in summer, it must not be possible for inflammable goods to +ignite by coming in contact with it; it must be a light that will have no +ill effect if by accident the key is left open; it must be a light that +our country cousins cannot blow out, neither must it be one that requires +dangerous matches to ignite it, and lastly, it must be a fairly cheap +light.</p> + +<p>Now, gentlemen, if you have thrown prejudice to the winds, perhaps you can +recognize in this ideal burner the incandescent electric light for +domestic use. Now, if this light is an ideal one, who is going to prevent +its adoption by the public? Gas companies cannot, and if they cannot no +one can. So, in my mind, the wisest course to pursue is to admit what we +know to be true, and proceed at once to supply the demand, increase our +revenue, push out into the suburbs of our cities, sell it as cheaply as +possible, and don't let others come in and take away what rightly belongs +to you. If there is any money to be made in the business by others, there +is still more in it for us.</p> + +<p>For store purposes, where the hours of burning are defined, I think it +better to abandon the meter system and fix a price per annum or month for +each lamp, taking into consideration the hours of use as a basis for +charges. For private dwellings this would not be practicable, and we would +have to resort in this case to meters, or perhaps fix upon a price for +furnishing the current and have the consumer purchase the bulbs or lamps +whenever renewals were necessary. In this way economy would cheapen the +light to the consumer. Any method that will dispense with the meter and +still be satisfactory will be the one to adopt.</p> + +<p>I cannot understand how some gas companies who have the incandescent +electric system as a competitor can console themselves with the fact that +it is not injurious to their gas business, even taking it for granted they +are selling as much gas as before its advent. Is this a just reason why +they should make no effort to secure their old patronage? I think not, for +it is human nature to secure a whole loaf in place of the half, when it is +possible to get it. A gas company's revenues would certainly be increased +by the step, and a dangerous rival would be made profitable.</p> + +<p>I think it is a mistake to think that by and by the people will get back +to gas. Of course some will, just as gas consumers sometimes go back to +coal oil; but, because a few give it up, don't let us deceive ourselves by +thinking that all will do it eventually, for the incandescent electric +burner is bound to remain wherever it is now in use, and will find its way +to the other places where it is not now in use. "That is all very well to +talk about," I hear some one say, "but what are they going to do with our +prior investment?" To such I would say, push that, too. Cheapen it to its +lowest point and urge its use for power and cook stoves until such time +that you find yourselves able to supply gas for heating purposes of all +kinds.</p> + +<p>What difference does it make to a company whether the money expended for +improvement account be coal gas benches, holders and mains, or dynamos, +boilers, and wire? I fail to see the difference, and if improvements have +to be made in both, so much the better—it shows a healthy demand for both +branches, and should be promptly provided for.</p> + +<p>If arc lighting is to be the light on our streets and the incandescent +electric light for our stores and dwellings, shall we have to draw our +fires from under our gas benches and stop making gas? This, to the writer, +would be an absurd deduction, for the very reason that in nature's +laboratory all these elements are placed, and gas would not be one of them +if there were not some important part for it to play in the supplying of +man's wants. It is for us to take the things we find in nature's +laboratory and select the fittest articles for each special use; and it is +reasonable to suppose that it will be only the fittest that will finally +be a success. The arc light, so far as the writer has ascertained, has +asserted pretty generally throughout the country its supremacy on our +streets, and this in spite of all opposition from gas companies—showing +conclusively that it has gained its position by the force of demand for +the fittest. Incandescent electric light is just as surely finding its +position and field of usefulness, and in its turn will assert its +supremacy, and why? Because it has the +<!--020.png-->qualifications called for in the +public specifications. Some will assert that it is too expensive to come +into general use, and also that it is not as reliable as gas. The first is +no argument against it, for was not coal gas sold at exorbitant prices in +its early days? It certainly is capable of being cheapened in the future, +as gas has been, and this is one reason why gas companies should enter the +business, as it is in their power to cheapen it.</p> + +<p>As far as unreliability is concerned, it certainly looks the most serious +objection; but don't be alarmed on that score, for duplicate machinery or +storage batteries will eventually overcome this bugbear, and while +discussing this subject don't let us forget that the breaking of a main, +the filling up of a drip, a flood or explosion, or even Jack Frost, has +often caused our customers to think that even gas is not very reliable.</p> + +<p>I cannot understand what prompts gas companies as a rule to prejudice +against electric lighting, unless it be they imagine the outcome to be +idle gas mains and cold benches. This I think is all wrong. The largest +unoccupied field to-day is the fuel gas field, and who should step in and +supply this demand? Could any one do it as well as the present gas +companies? We have our mains and services already laid; we have our +holders, meters, and trained labor, most of us have also the necessary +land to spare on which to erect the generators.</p> + +<p>Next to the fuel gas field I think I can see another field nearly as +extensive, and that is the coal oil field.</p> + +<p>Please imagine the following picture, which is representative of the +writer's belief of what a gas company will be in the near future; in fact +so near in the future that before our next convention rolls around it will +be a reality.</p> + +<p>One set of officers, whose principal qualifications shall be +progressiveness—their duties to be divided between electric lighting of +all kinds, including electric power, fuel gas for all purposes, including +gas engines; also incandescent lights off fuel gas mains.</p> + +<p>Now let us see what the plant will consist of. One set of mains for fuel +gas, from which our patrons will draw all their fuel, and also light, if +they wish. Gas engines will be run economically with this gas. One set of +meters only will be required.</p> + +<p>There will be no coal gas benches as we have them now, as the method of +manufacture is too laborious, too expensive and very primitive, not to say +barbarous—everything now being built on the horizontal plan, requiring +the greatest possible exertion to both draw a charge and stoke. The +generators of the future will be on the cupola style, feeding by +gravitation from the top. Native coals in all probability will be +sufficiently good to make gas of. One portion of the plant will be devoted +to the dynamos and engines for furnishing the electric light. Where the +coal gas benches now are will be boilers, or perhaps even these will be +unnecessary if gas engines be used. If steam boilers be used, they will be +fired with producer gas, and the holders will become simply pressure +regulators. The revenues of gas companies will be increased fivefold, if +not more; the consumer will get cheaper fuel, cheaper power, and cheaper +light.</p> + +<p>Native coal fields will become more valuable, and we will not pay tribute +to other States, as heretofore. The change from illuminating coal gas to +fuel gas will perhaps be a slow one, owing to the conservatism of gas +companies and imperfected details; but eventually it will be brought about +in spite of all obstacles. If a company is operated as pictured, it will +furnish arc lighting, incandescent electric lighting, and electric motors, +fuel gas, incandescent gas lighting, and gas engines.</p> + +<p>Gas will be made on a larger scale, with less dirt and nuisance, and +without that laboriousness now made necessary. Valves, levers, and push +buttons will displace scoop, drawing hook, and wheelbarrow, and the +employees will no longer be known as "gas house terriers," but will become +elevated to a higher plane. The officers of the company will also of +necessity have to be more active and alert, and the rule of thumb will be +at a discount. Now let us see where the gas man will be who fails to +occupy these new fields of pasture green.</p> + +<p>He will, of course, go on making coal gas in the old way; he will still +wrestle with stopped stand pipes, steam jet exhausters, naphthaline, etc., +and worry over how much a bushel of coke weighs. He will try to convince +his customers that he knows better than they do what they want, and that +anything but his gas is of no account. He will keep on cutting out items +from the newspapers whenever he finds it recorded that an electric light +somewhere failed to flicker.</p> + +<p>He will still maintain that there is not a company in the country making +anything out of electric lighting, and that it is only a matter of time +when some fellow slips into his town and, noting things, works up an arc +light company, captures the street lighting and some of our friend's best +consumers. The price of gas is lowered; all kinds of patent gas burners +are invested in to recapture those lost consumers; a fight ensues, +factions are made in the town, and the arc light company adds an +incandescent plant to the arc light, and captures more of our friend's +consumers. To cap the climax, another fellow comes along and proposes to +supply fuel gas to the citizens, gets a franchise, puts in pipes and +services, and our friend wakes up some fine morning to find that what the +electric light fellow has left him in the shape of lighting has been +captured by the fellow with the fuel gas plant, who puts in the +incandescent gas burners.</p> + +<p>Evidence is cropping up all around us that tends to this change. We find +manufacturers of fireclay goods now making carbons for electric lighting; +we also find gas fixture manufacturers now making and selling electric +wires of all kinds, besides other apparatus connected with the electrical +field. Manufacturers of meters have not yet devised a meter for measuring +electrical currents, but perhaps it would pay them to devote a portion of +their time to studying one out. As far as the present meter business is +concerned, I think, if this transformation of the gas business is brought +about, the demand for gas meters would be quadrupled and the use of the +larger sizes of meters would be made necessary; but if accuracy could be +insured with a much smaller meter with quicker action, I think it would be +better adapted for the purpose. Fuel gas, if it can be manufactured at a +price at which it could be sold with profit at a lower or as low price as +coal, would prove a larger field than all the kinds of lighting put +together, and is certainly worth our while to +<!--021.png--><span class="pagenum"><a name="Page_10350" id="Page_10350">10350</a></span>investigate +thoroughly. The +owners of the smallest houses of our cities would become our patrons, and +a small profit per thousand would represent a wide margin when taking into +consideration the large amount that would be consumed.</p> + +<p>But is the fuel gas practical, and has there been sufficient progress made +to date to warrant gas companies taking hold of it with any assurance of +success?</p> + +<p>In the first place, what assurance do we require? Do we want some one to +come along and guarantee us a profit of 20 per cent. on our investment if +we enter the field? If so, the patentees of the different processes might +just as well negotiate with the shoe maker as with the gas company. I +think all the assurance we want in the premises is that with certain +apparatus we can get certain results from a ton of coal (the kind of coal +being specified), or that from a ton of coal we can get a certain amount +of available deliverable heat units.</p> + +<p>The balance we should be capable of working out ourselves, such as labor, +leakage, cost of gas at consumers' meters, and such other data that we +certainly should be more familiar with than any one else.</p> + +<p>Of course, the fuel gas will have to have an odor, and must be delivered +at a proper pressure; and proper appliances for governing supply and +insuring perfect safety will have to be calculated on. In fact, the gas +man must try to improve on methods adopted, and do his best to hasten the +day when solid fuel in our homes shall be no more—in other words, we have +to take hold of the fuel gas business in its infancy or it will get weaned +away from us.</p> + +<p>Mr. McMillin, with others, has given us some figures on fuel gas which +have been verified by practical tests. For instance, he gives us as his +opinion that a mixed gas is more adapted for all-round purposes than +either coal or water gas alone.</p> + +<p>From experiments made we find that from a ton of bituminous coal, making a +mixed gas, we can realize as salable gas 63 or 64 per cent. of the total +heat units in the original ton of coal, or about 17,000,000 heat units, +besides a residue of heat sufficient to produce the steam for making the +above amount.</p> + +<p>Of this mixture 20 per cent. is coal gas, made in the ordinary way, which +is the only objectionable feature the writer can see in the process. I am +inclined to think that Mr. McMillin rather strained a point here in order +not to alarm coal gas men, or else to avoid a too radical change in the +apparatus now in vogue for making coal gas.</p> + +<p>By his statement we find that in water gas, labor and repairs cost but 7 +cents per M, while coal gas costs for the same items 15 cents per M. Of +course, the proportion of coal gas made by the old method is of more value +in heat units than the water gas made by the new method; but what I wished +to suggest was this, that if the whole process be made in the cupola as +water gas is now made, whether the result would be the same number, or +nearly so, of heat units in amount of gas made, with a large reduction in +labor making the coal gas cost no more than the water gas for the item of +labor repairs. If the mixture can be made in this manner, and I have some +assurance that it can be done successfully, then I think it would pay any +company to abandon the use of the present style of gas benches, and use +the space now occupied by them with more improved apparatus, rather than +use them at a loss, simply because we have them on hand.</p> + +<p>We have pictured an ideal burner for our homes in the fore part of this +paper, and I cannot refrain from holding up to your view this ideal fuel, +which has no smoke, no dirt, no ashes, and entails on the housewife no +extra labor, can be regulated automatically to one steady temperature, and +does not require a workingman, after doing a hard day's work, to come home +and find a ton of coal dumped on the front sidewalk, which has to be +wheeled or carried in before night comes on.</p> + +<p>Now that we have seen an ideal street light, an ideal house light, and an +ideal fuel, we will endeavor to show you an ideal gas company; and we +cannot do it in a more concise way than to say that an ideal gas company +is one that keeps all these ideal commodities for sale at a reasonable +price.</p> + +<p>This may look visionary on my part to some of you, perhaps all of you; +but, nevertheless, I feel that this is the place and time to talk over +"our future prospects," and if this paper is the cause of any one +investigating the subjects spoken of or bringing forth discussion +regarding the same, I shall feel I have not written in vain.</p> + +<hr class="ChapterTopRule" /> + +<h2><a name="THE_APPLICATION_OF_ELECTRICITY_TO_LIGHTING_AND_WORKING5" id="THE_APPLICATION_OF_ELECTRICITY_TO_LIGHTING_AND_WORKING5"></a>THE APPLICATION OF ELECTRICITY TO LIGHTING AND WORKING.<a name="FNanchor_5_5" id="FNanchor_5_5"></a><a href="#Footnote_5_5" class="fnanchor">[5]</a></h2> + +<div class="c3">By <span class="smcap">W. H. Preece, F.R.S.</span></div> + +<div class="c3">LECTURE I.</div> + +<p>I appear before you to give a short course of two lectures on the +application of electricity to lighting and working. To-night I shall +confine my attention entirely to lighting, and if we succeed in getting +through our subject, we shall devote ourselves next Wednesday to the +application of electricity for working tramways, to the transmission of +power for various purposes, and generally to working.</p> + +<div class="footnote"><p><a name="Footnote_5_5" id="Footnote_5_5"></a><a class="label" href="#FNanchor_5_5">[5]</a> Two juvenile lectures recently delivered before the Society +of Arts, London.—<i>From the Journal of the Society.</i></p></div> + +<p>Many people imagine the electric light to be a cold light. It is a +delusion. It is called a cold light because in many of its forms it gives +what we may call a cheerless light; it has not got the warmth, the +comfortable look, of other artificial means of illumination.</p> + +<p>The electric light owes its existence to the intense heat that the +electric current produces, and heat lies at the root of every system of +artificial illumination. For instance, suppose we take a common match and +light it, we light it simply because by the friction of the two surfaces +together we generate heat, the heat burns the substance of which the match +is made. We are able to light a common candle because we have applied heat +to the wick, the heat liquefies the wax of which the candle is made, the +wax is decomposed, it combines with the oxygen of the air, intense heat is +produced at that point, carbon is consumed, and the consequence is light. +So with all our various modes of artificial illumination. Gas, as you are +well aware, produces intense heat, and the result of that heat is light. +There are various ways +<!--022.png-->in which gas is applied to produce heat and the +necessary consequence—light. Here is a Sellon gas burner, in which the +combustion of gas raises the temperature of a fine platinum cap, and the +result is, as you see, a very beautiful light. In one lamp we have a cap +or mantle, in the other case there is merely a flat disk gauze of +platinum. The combustion of the gas produces intense heat, which raises +the network to a very high state of temperature, though in the present +case the light is not so good as it should be, probably through the +pressure in the supply main not being sufficiently great.</p> + +<p>In another case we have a gas jet surrounded with a network of some +vegetable matter, linen or cambric, steeped in a solution of salts of +zirconium, and a few other rare earths, and the intense heat of the gas +causes a very high temperature, and, as you see, a very brilliant effect +is produced.</p> + +<p>You will see from this that in all cases of artificial illumination bodies +have to be raised to a high state of temperature. I hold in my hand a +piece of magnesium wire; it is really flat magnesium tape, but it is +called wire. If I heat that, you will observe that a very brilliant light +is produced, due to the very high temperature at which it burns. Now, if I +take a lump of coal and heat it—it requires to be raised to a certain +temperature before the oxygen is directed upon it—and subject it to a jet +of oxygen, you will see that it burns with very much more intense light +than you are accustomed to in the ordinary fire. If I take a piece of iron +wire and place it in a jar of oxygen, you see what a very brilliant effect +the combination of oxygen and iron produces through the iron being raised +to a very high temperature.</p> + +<p>I have now shown you that in order to produce light we must, by some means +or other, raise the temperature of a body. But the high temperature that +we have to deal with is not that produced by the combination of the oxygen +of the air and carbon, and other bodies such as I have shown you, but it +is produced by the aid of the electric current. In all these cases the +result of the combustion you have seen has been to remove oxygen from the +air, but now I want to show you how a body can be raised to a high state +of temperature without combustion of any kind. In front of me I have a +fine platinum wire. In my hand I hold a wire that is in connection with a +battery upstairs, the other wire in connection with the battery is +attached to the far end of the fine platinum wire; now, when I make +contact with the near end of the platinum wire, you observe that the wire +is raised to redness, its temperature is high, and as I reduce the length +of the platinum wire it gets brighter and brighter, the amount of +electricity passing through it is greater and greater, and presently the +wire is fused. I should have pointed out that as the quantity of heat +generated in a wire increases, so does the color of the light. When heat +is applied to a body, that body is first warmed, then it gets gradually +hotter and hotter, until it becomes red hot, and the first color that +appears is always red. The temperature is further raised, and the body +assumes the color of orange, then at a little higher temperature it +appears yellow, and so the different colors of the rainbow are perceived +according to the different temperatures to which the body tested with is +raised. Now, I want to show you the most intense form in which heat can be +produced on this earth. There is no hotter object that we can obtain than +that of the electric arc. I will try and produce this arc. You observe +that when I bring these two pieces of carbon together, a current of +electricity passes between them, and the passage of the current of +electricity between them creates such an intense temperature that a +brilliant white light, as you see, is produced. Incandescent particles of +carbon pass between the two points, forming a sort of bridge or arch, +which is called the electric arc. But the temperature of this arc is, as I +said before, the highest temperature that we can produce; it has been +measured, and is found to be 8,500° Fahr. That is a temperature that can +hardly be conceived; the melting point of iron is only about 1,200° Fahr.; +the melting point of platinum, which is one of the most refractory metals +we have, is about 3,000° Fahr.; but here in the arc we have the intense +temperature that nothing can withstand, equal to 8,500° Fahr. The color is +really due to the combustion that takes place between the materials +forming the arc. I have just used two pieces of carbon, but I will now try +other materials—copper, iron, and zinc. You will see a difference in the +color of the light, due to the fact that metal is burned in the arc +instead of carbon. Every metal has its own distinct and particular color, +and the presence of the different metals can be detected by the character +of the small arcs produced.</p> + +<p>I have shown you that we have two modes of producing intense heat, and +therefore light, by electricity. I want now to show you how we produce +electricity. The first essential for the production of electricity with a +hand machine like this is a good dinner. The energy provided by beef or +mutton enables the operator to turn the big wheel of the machine, whence +motion is transmitted to the apparatus for producing the electricity. This +machine when rotated causes a coil of copper wire to be whirled in a +magnetic field, and that rotation of the coil in a magnetic field converts +the energy derived from the grass and from the mutton through the machine +into electric currents; those electric currents flow through wires that +are under the table, they will appear in the two wires I hold in my hand, +and will, I hope, reappear in the little glow-lamps I have before me in +the shape of heat, and then of light when I attach the wires. The light of +the glow-lamp is of just the same form of energy as that which passed from +the sun to the earth, and by beginning backward from the lamps we have +light, heat, electric currents, mechanical motion, food or fuel in the +shape of mutton, grass on the South Downs, to the sun. Whichever way it is +taken, you will find there is direct action between the sun and the +glow-lamp. The lamps are now burning, and you see that we are able to +produce electricity to our hearts' content. Down-stairs there is a +gas-engine; the gas-engine is at work; the gas-engine works because the +gas supplies energy which, stored up in the bowels of the earth in the +form of coal for ages and ages, has been extracted; it has been converted +into gas at the large gas works down the River Thames, it has been brought +up here, it is burned in the gas-engine, and produces energy in the +gas-engine exactly in the same way as the mutton or +<!--023.png-->beef produced energy +just now. There is a dynamo down-stairs exactly like the dynamo that we +have upon the platform, and the current that is produced is exactly as the +current we just obtained, and is sending electricity through all the lamps +in this room. The currents of electricity passing through the lamps are +producing intense heat, the heat is producing the incandescence of a fine +carbon filament, such as I will show you directly, and the consequence is +that we are now being lighted in this room by the energy that unmistakably +and undisputably arrived on this earth millions of years ago in the form +of sunshine.</p> + +<p>We can store up the energy in batteries. I shall show you to-night two or +three different forms of battery. Here is what is called a primary +battery. The only difference between a primary battery and a secondary +battery is this, that a primary battery consists of chemical elements that +at once combine and produce electricity by combustion, whereas a secondary +battery involves some anterior electrical action, which prepares the +surfaces of two bodies to put them in exactly the same condition as a +primary battery. Here is a primary battery known as the Schanschieff, +which is charged with a solution of sulphate of mercury, and into that +sulphate of mercury we will dip plates of zinc and plates of carbon. Zinc +has a greater affinity for the sulphuric acid of the sulphate of mercury +than mercury has; the sulphuric acid will at once combine with the zinc; +it will burn the zinc just as the gas burned just now, but instead of +burning with heat and light in the battery, it burns in the form of +electricity, which appears in the glow-lamps attached. You see that the +moment the zinc and carbons are placed in the cell electricity is +produced, and the lamp is lighted. The form of battery from which we are +drawing our electricity to-night is the accumulator, or the storage or +secondary battery. The secondary battery simply consists of plates or +"grids," as they are called, one filled with litharge, and the other with +red lead; the one becomes pure lead, the other becomes peroxide of lead; +the plates are combined in this form, and then placed in a glass cell, and +upstairs there are 52 of these E.P.S. cells, which have been charged all +day long by the gas-engine of which I spoke, and which now contain a store +of electricity that I shall make considerable use of to-night before I +finish.</p> + +<p>I showed you the form of electric light which we call the arc, and I have +here to-night two or three different forms of arc lamps, which I will show +in action. But I want you to see this arc light for yourselves, and I want +you to feel, as I feel, that in all nature there is nothing more wonderful +and nothing more beautiful than the action of electric currents in the +arc. The light is, as I attempted to show you, the very same light that +came from the sun. I can show you that it is of the same character as the +light of the sun, and in the lantern on the table there is an arc lamp the +light of which we will throw on the paper before me in the form of a +spectrum. There you see the spectrum in all its purity; the spectrum from +the sun is no purer as regards light than what you now see. There you see +all the colors of the rainbow, and I had intended, if it were possible, to +show you in the first experiment, in which we raised platinum wire to +incandescence, that the first color would be the red, then the orange, +then the yellow, then the green, then the blue, then the indigo, and +lastly the violet. Beyond the violet there are rays of light which we +cannot see; they are the rays that produce the photographic pictures, and, +had time permitted it, we would probably have taken to-night a picture by +means of the arc lamps, but it requires a long time to do so, and it +really is no more interesting than an ordinary photographic picture. There +are all the different colors of the rainbow. Those who are anxious to +remember the order of the colors can very easily do so if they will +remember this simple sentence, "Read over your good book in verse." The +first letter of each word in that sentence gives the first letter of the +color in the order of the spectrum. It would be a very good thing if some +of our artists were to study and remember the colors of the rainbow, for +it is an extremely rare thing indeed to find a picture with the colors of +the rainbow properly depicted, sometimes they are upside down, sometimes +they are mixed, and if you discuss the fact with an artist, he will say, +"I do not care about your science. I simply paint my own impressions."</p> + +<p>I will now show you the arc in another form. We are to-night connected in +this room—I have told you there is a gas-engine down-stairs; there are +also secondary batteries upstairs—but we are in connection with the +Grosvenor Gallery in Bond Street. The Grosvenor Gallery has a central +station where a very large dynamo is at work, from which electricity is +supplied to different parts of London; many thousand lamps are fed, in a +great many clubs, theaters, and private houses; they are all lit up by the +currents generated underneath the Grosvenor Gallery. The Grosvenor Gallery +Company, through their engineer, Mr. Ferranti, have very kindly undertaken +to supply us to-night with a current. The current is supposed to be a very +dangerous one, in reality it is not; there is no electric current that has +ever been produced that is one-tenth as dangerous as a steam boiler, and +all these currents, however immense they may be, are very simply +controlled, and very easily brought within the region of safety. There is +no doubt that with the apparatus that is now being handled in this room, +if anybody were deliberately to put one wire in his mouth and the other in +his hand, he would have the funeral service performed over him in two or +three days; but those who know what they are about no more handle electric +light wires carelessly than they put their hands in a furnace or their +noses in boiling water. We acquire experience by practice, and we know by +this time pretty well how to deal with electric currents. Now, you see in +the lower arrangement there that safety catches are being put in, which +render any accident quite impossible. Passing through each of those boxes +there is what is called a "cut-out" safety fuse, or safety valve, and +should, from any accident, anything go wrong in this theater, or in any +way with the system outside the theater, the safety fuses would burst, and +would so remove all danger from inside. The switch has now been turned, +and by it the current from the Grosvenor Gallery has been brought within +our reach. You see an arc light produced by it, and you see how intensely +bright and brilliant that light is. I do not want you so much to see that +light itself, but I want you to see its projection, or picture; and if Mr. +Wickham will kindly direct it on that white paper, at the +<!--024.png--><span class="pagenum"><a name="Page_10351" id="Page_10351">10351</a></span>end +of the room +furthest from the table, you will see a picture of the carbons which are +now emitting that intense and brilliant light. You will see that between +what appears to you as the top carbon (but which is in reality the bottom +carbon of the two) and the bottom one there is playing, apparently, a +shower of minute fragments of something, but which are in reality +innumerable minute flashes of lightning, there is a constant uninterrupted +shower of electric shocks passing, that produce that intense brilliancy, +and that very bright appearance. There is intense commotion, a terrible +surging about of matter in a molten condition. Well, that arc that you see +is produced by the currents from the Grosvenor Gallery. They are +alternating currents of electricity, currents that are constantly and +suddenly circulating backward and forward. The arc that we have at this +other end of the room is a direct current one, and it is now projected on +to another sheet of paper, where you see a different form of are +altogether. This arc is produced by the direct current from a battery. You +will see the form is quite different from that in the alternate current +arc. You heard a peculiar hissing sound just now; that is a peculiar +phenomenon in arc lamps that has attracted a good deal of attention from +physicists, but nobody has yet arrived at a satisfactory conclusion as to +the cause. The lamp sometimes sings and sometimes hisses, and while thus +behaving it produces an intense and variable inverse electro-motive force, +that has to be overcome before the current can produce a steady and silent +arc. You will notice in the upper carbon of this form of lamp a kind of +cup, or "crater." The lower carbon forms a kind of point, a raised +surface, and between the two there is on the projection that which appears +as a glow, but which in reality has very intense heat, reaching, as I told +you, a temperature of 8,500° Fahr. In those two projections you have, I +think, within my experience for the first time, been shown in public an +alternate current arc and a direct current arc at the same time, so that +you are really able to see what I do not think most people have seen +before.</p> + +<p>There are a great many different arc lamps. I have not time to bring +before you all the various lamps that I might have secured for your +inspection. There is the Brush lamp, that for a long time lit up the +streets of our city, and I sincerely hope very soon is going to light up +the city again. There was the Jablochkoff lamp, that lighted up our Thames +Embankment, and which can be seen, on going down the Strand, at the Tivoli +Restaurant, not far from here. The offices of the <i>Daily Telegraph</i>, in +Fleet Street, and many other places, are lighted up by different lamps, +many of them excellent. Our experience of the last two or three years at +the exhibitions has taught us that there are a great many different kinds +of arc lamps, but all these arc lamps are lamps so constructed that they +cause the pair of carbons to be fed, to be kept together, as they consume, +at the same rate as they do consume. The mechanism is of great delicacy, +it acts with great promptitude, and the one that we have here to-night is +one of the last and one of the best; it is known as the Brockie-Pell lamp. +The lamp now at work is a Brockie-Pell, and for those who are interested, +a diagram representing it is upon the wall, and its operation I shall be +very happy to explain after the lecture; it feeds with great rapidity, +with great convenience, and is one of the steadiest lamps we have.</p> + +<p>There are objections to the arc light; it is extremely dazzling and +irritating to the eye. Although the arc lamps we have here to-night are of +the very best of their kind, and are certainly almost steady, still they +have little irregularities in their action, and worst of all, they throw +intense shadows. The light from them is not very well diffused, still the +light is very brilliant, and it raises the envy of a good many people. For +instance, the Brush Company were once establishing a light in the +neighborhood of Cork, and an Irish farmer was remarkably struck by the +appearance and the steadiness of the light, so he came to the engineer in +charge and asked him, as a great favor, if he could kindly tell him where +he got his oil from.</p> + +<p>I must now go from this to the next branch, the glow-lamp, the lamp that +is burning so steadily and so nicely above us. For this lamp we do not use +platinum, such as I heated before you just now, but we use carbon, so fine +that although I have probably one hundred or more in my hand, they feel no +heavier than a feather. These extremely fine filaments of carbon are made +with very great care from cotton. I cannot show you the whole operation of +making carbons and some of the preliminary operations connected with the +making of the lamp; but owing to the kindness of the Anglo-American Brush +Company, their manager, Mr. Sillar, is here to-night, and we shall have +the pleasure of seeing how the whole operation of the manufacture of one +of these glow lamps, such as we have above us now, is carried out. The +carbons have already been formed, but the first process is that the cotton +fiber is carefully tied and wrapped around pieces of carbon, as you see. +It is then placed in a furnace and carbonized. After being thus prepared, +a glass tube of special quality selected for the purpose is used to form +the glass globe. Mr. Donaldson will take a piece of the glass tube before +you, and will blow it into the shape similar to the lamp I hold, which is +of the very familiar pear-like form. The carbon filament will then be +fixed in the glass bulb, the latter will be exhausted and sealed, and the +whole process be passed through before your eyes. I must first of all show +you why it is necessary to take all this care. We have in front of the +board one of these carbon filaments suspended, and we will now pass a +current through it, and the carbon filament is raised to incandescence, it +combines with the oxygen of the air, it is at once consumed, and, as you +saw, we only had a light for a few seconds. Now, in order to make that +light permanent, it is necessary to inclose the carbon filament in a glass +globe, and to exhaust from that glass globe all the air, or as much of it +as possible, and then, instead of having a life of a few seconds, the life +of a lamp frequently continues for 4,000 or 5,000 hours. The first +process, as I said, in making an incandescent lamp, after the carbon +filament has been prepared, is that of blowing a glass bulb. The blowpipe +has now been put on, and the intense heat of the Bunsen burner raises the +glass to incandescence, to a soft, plastic condition, so plastic that the +manipulator can do with it just +<!--025.png-->whatever he likes. Having got the glass +to this particular shape, the filament will be placed inside it, first of +all mounting the filament, which is an operation requiring a great deal of +care and great skill in handling. It is an extremely pretty operation, and +I beg to call your attention to it. The carbon is fixed inside a fine +spiral of platinum, which is at the same time subjected to an intense +current which decomposes the oil or the hydrocarbon in which it is placed, +the carbon deposits on the carbon filament, and cements it to the platinum +spiral. That is called mounting the filament. When that is done, the +filament is fixed in the glass globe, and the platinum and glass are fused +together. The brilliance of the platinum can be seen during this +operation, and it is very pretty. I do not know how it would have been +possible for us to have glow-lamps if it had not been for the fact that +the coefficients or rates of expansion of platinum and glass are +practically exactly the same, and the result is that when the platinum and +glass are combined together, as they are in a glow-lamp, the two contract +and expand at the same rate, and the result is there is no leakage; if +there had been leakage through the glass, it would have been quite +impossible to have made a glow-lamp. The success of a glow-lamp depends +upon the vacuum produced, and the next process is to cement the lamp so +far to a vacuum tube connected to a mercurial air-pump. The one before you +is Mr. Lane Fox's. It would have been also impossible to have produced +these beautiful glow-lamps without the mercurial air-pump, so that the +success of electric lighting and its perfection depend upon, first, the +similarity of expansion of glass and platinum, and secondly upon our power +of producing a vacuum. As it takes ten minutes or a quarter of an hour to +carry out the process of exhaustion, I will proceed with other portions of +my subject, and presently, when the time is ready, Mr. Sillar will inform +me, and we will light up the lamp that has been made before you this +evening, and, I hope, with success. The operation we have just seen is one +that has been just as interesting to me as it has been to you. There are +very few who are permitted to see this operation. We once had it before in +this hall when General Webber read a paper on glow-lamps, but with that +exception I am not aware that the manufacture of glow-lamps has ever been +shown in public before. It is most wonderful to watch the marvelous way in +which glass can be twisted and turned to our ways and to our wants, and +the skill with which the blower is able to manipulate glass in its plastic +condition, and to shape it in any form he likes, is an operation which +never ceases to excite one's wonderment. The form of lamp that is being +made before us is of the ordinary size that we see used generally, but +there are a great many different sizes of glow-lamps. For instance, here +is a very small lamp; above me you will see, if I may call the small one a +dwarf, there is a giant glow-lamp. It is a lamp invented by the Honorable +Charles Parsons, it is made by the Sunbeam Lamp Company, of Gateshead, and +is called the Sunbeam lamp; it has the same proportion to an ordinary lamp +that an ostrich egg has to a hen's egg, and the light from it is of +equally large proportion, as you see now the current has been turned on to +it. It gives a light of four hundred candles, but it is rather too +brilliant I see by your faces, and we will go back to our old friends of +the ordinary size. There are also above us lamps of various sizes; there +is a five-candle, ten-candle, sixteen-candle, twenty-candle, and a +hundred-candle lamp. Here also are a fifty-candle Swan lamp, a +sixteen-candle Swan, and an eight-candle Swan lamp. There are the ordinary +sixteen-candle lamp; these are being burned from the Grosvenor Gallery. +Here is a miner's lamp, which is supplied with a current by the +Schanschieff battery, the same as I showed you at first. The peculiarity +of this arrangement is that when the battery is turned upside down the +light goes off, the zincs and carbons occupy one half of the cell, and the +solution the other half, the zincs and carbons being at the bottom, and +the battery is not excited unless contact is made with the carbons and +zinc. Such a battery as this will maintain its lamp for 12 or 13 hours. +There are several forms of the Schanschieff battery. Here is a portable +form, and lamp connected with it by a flexible wire, which can be used +when traveling; or in the night, when you want to know the time, you can +have a lamp and battery like this by your bedside, and you can turn it +upside down, and produce a light, see the hour, and turn the battery back.</p> + +<p>These glow-lamps are used for different purposes and ways. They may be +used with care, they may be used recklessly; their duration depends a good +deal upon the care with which they are used. A practiced eye, one who is +accustomed to deal with electric lamps, can tell at a glance when the lamp +is raised to a proper incandescence; but there is a point in all lamps +that is a sign of danger, and indicates "breakers (or breakage) ahead." +Whenever in an electric light installation a glow-lamp begins to show a +blue effect, then breakers are ahead; the current must be reduced or other +steps taken. I want to show you this blue effect, which is extremely +pretty, and I want you to see the gradual stages through which a lamp +passes from long life to death, or rather to a very short and merry life. +We can make the life of a lamp just exactly what we like; we can make a +lamp last a minute, or we can make it last a hundred years, and the number +of years of its duration is simply dependent upon the current employed. I +have here a glow-lamp, and I pass a current through it. There is no blue +effect at present; the current is increased, and the carbon filament is +raised to a high state of incandescence. In such a state it would not last +for a long time, not more than ten minutes or a quarter of an hour; but it +does not show the blue effect yet. On further increasing the current the +blue effect appears, though I doubt whether it is visible to many of the +audience; a little more current is put on, and the blue effect is very +marked, the globe itself looks very brilliant, and—there—the current has +been increased until the filament has parted.</p> + +<p>It is always better, when making an observation or experiment, to know +what you are going to see, so that you can direct your attention to +exactly what is being done or to what you want to know. If I put another +lamp through the same experiment, you will be better able to understand +this blue effect, and see just that point where the lamp is about to give +out. The current is now on, and is being gradually increased; the lamp is +now intensely blue, and—there—it has gone in the same way exactly as the +other one did. The way +<!--026.png-->in which lamps burst is sometimes very beautiful; +they disintegrate, they seem to volatilize, and the substance of the lamp +is projected with great force against the side of the globe. On the table +there are several beautiful specimens showing this effect.</p> + +<p>The glow-lamp in process of manufacture before you is now being unsealed +from the pump; it is now exhausted, and we will pass a current through it +so as to raise it to incandescence. The current is now on, and you see the +lamp burns with full brilliancy. The next experiment is rather a cruel +one, because it is willful destruction. I will not destroy the lamp that +has just been made before us, for I will keep it as a memento of this +evening. I want to show the safety of the electric lamp. Many people +imagine that there is a great deal of danger about it. I will take a +handkerchief, and in it place a lighted lamp, when, on the globe being +broken, the carbon filament instantly goes out, and there is no damage to +the handkerchief, or the slightest appearance of scorching or heating upon +it. On breaking that lamp you heard a report. That is due to the vacuum, +which, on sudden rupture, the air rushes in to fill. These lamps will not +only burn in air, but will actually burn in water. Here I have a lamp +which on placing in a bowl of water continues alight in the water just as +well as in the air. You can imagine what an immense boon that is to our +divers and others who unfortunately have to work under water for our +benefit.</p> + +<p>I will not attempt to occupy your time in speaking of the beauties of this +wonderful light, how it removes really poison from our air, how it is very +good for sore eyes, because it burns with such steadiness that those who +work under it really never find, in any shape or form, any inconvenience +or discomfort to the eyes. It is extremely cleanly; it does not fill the +air we breathe with noxious fumes. People are little aware of it, but it +is a very simple calculation to show that thirty gas burners produce a +gallon of water in an hour, so that if you have thirty burners in a shop, +for instance, alight for six hours, six gallons of water are produced and +the water can very often be seen running down the cold windows of shops. +That water absorbs sulphur and sulphuric acid, and when deposited on books +and decorations destroys them. If we could only get the electric light +cheap, delivered at our doors, then everybody who has an idea of luxury +and comfort would at once take it.</p> + +<p>I want now to show you some of the dodges of the electric light. First I +will show you that by the action of a cut-out an excess of current is +prevented from injuring the lamps. A cut-out is inserted so as to protect +a group of lamps here, and on a large current being sent you hear a crack, +and the lamps have gone out; the safety fuse has perished in performing +its duty. To prove this we will renew the cut-out, and on the proper +current being turned on, you see the lamps are sound. Here is an electric +cigar lighter. I raise this up and the wire in front of it comes to a +state of incandescence, and I have there, as you see, sufficient heat to +light my cigarette. Some years ago, I had my daughter's doll house, which +was furnished by herself, fitted up with the electric light, and I thought +that some of my younger hearers to-night, who were still in the doll age, +would appreciate the way in which a doll's house can be lighted up by +electricity. You now see the doll's house illuminated; it has a hall door +lamp which lights up on the opening of the door; the house has rooms +furnished, occupied with handsome dolls, and fitted with every kind of +contrivance; the doll who occupies the drawing room has the convenience of +a portable lamp, which she can move about wherever she likes, and each +room and the kitchen has a particular form of lamp.</p> + +<p>I have also here a model of that famous ship the Captain, which was +wrecked off Cape Finisterre. The model has been fitted with electric +light, and you now see the mast head-light, the red light for the port +side, and the green light for the starboard side; there are high jinks +going on in the saloon by the aid of the electric light, and there is also +a search light which can be used for looking for the advance of the enemy. +A beautiful phosphorescent effect is produced upon the water, which is +covered with blue cotton wool, in which a lamp is placed, causing really a +very pretty illustration of what the phosphorescence of the sea is like.</p> + +<p>Here I have an apparatus for heating curling tongs by electricity; here is +a flat iron treated in the same way, and here is a kettle in which the +current is carried to boil water. I travel a good deal, and I always carry +in my traveling bag a battery like this, which is one of Pitkin's +secondary batteries; it is light and extremely convenient. I can strap it +on my shoulder like an opera glass. To this is attached a reading lamp +which I fix in my waistcoat, and to the astonishment of my fellow +travelers, when the shades of evening are beginning to set, I take out the +lamp and put it in operation—so. My reading lamp is thus provided, and it +is fixed in the most convenient position, for the light falls just where +it is wanted, it does not offend the eye, and enables me to read the +smallest print. I have always got with me my own light, perhaps much to +the annoyance of my fellow passengers, and with the electric light +machinery at my own house, I have little or no trouble in recharging the +battery, or keeping it in order. The Pitkin battery is also applied to a +miner's lamp.</p> + +<hr class="ChapterTopRule" /> + +<h2><a name="EFFECT_OF_CHLORINE_ON_THE_ELECTRO-MOTIVE_FORCE_OF_A_VOLTAIC_COUPLE6" id="EFFECT_OF_CHLORINE_ON_THE_ELECTRO-MOTIVE_FORCE_OF_A_VOLTAIC_COUPLE6"></a>EFFECT OF CHLORINE ON THE ELECTRO-MOTIVE FORCE OF A VOLTAIC COUPLE.<a name="FNanchor_6_6" id="FNanchor_6_6"></a><a href="#Footnote_6_6" class="fnanchor">[6]</a></h2> + +<div class="c3">By <span class="smcap">D. G. Gore, F.R.S.</span></div> + +<p>If the electro-motive force of a small voltaic couple of unamalgamated +magnesium and platinum and distilled water is balanced through the coil of +a moderately sensitive galvanometer of about 100 ohms resistance, by means +of that of a small Daniells cell, plus that of a sufficient number of +couples of iron and German silver of a suitable thermo-electric pile (see +Proc. Birm. Phil. Soc., vol. iv., p. 130), the degree of potential being +noted, and sufficiently minute quantities of very dilute chlorine water +are then added in succession to the distilled water, the degree of +electro-motive force of the couple is not affected until a certain +definite proportion of chlorine has been added; the potential then +suddenly commences to increase, and continues to do so with each further +addition within a certain limit. Instead +<!--027.png--><span class="pagenum"><a name="Page_10352" id="Page_10352">10352</a></span>of +making the experiment by +adding chlorine water, it may be made by gradually diluting a very weak +aqueous solution of chlorine.</p> + +<div class="footnote"><p><a name="Footnote_6_6" id="Footnote_6_6"></a><a class="label" href="#FNanchor_6_6">[6]</a> Read before the Royal Society, May 3, 1888.</p></div> + +<p>The minimum proportion of chlorine necessary to cause this sudden change +of electro-motive force is extremely small; in my experiments it has been +one part in 17,000 million parts of water;<a name="FNanchor_7_7" id="FNanchor_7_7"></a><a href="#Footnote_7_7" class="fnanchor">[7]</a> or less than <sup>1</sup>⁄<sub>7000</sub> part of +that required to yield a barely perceptible opacity in ten times the bulk +of a solution of sal-ammoniac by means of nitrate of silver. The quantity +of liquid required for acting upon the couple is small, and it would be +easy to detect the effect of the above proportion or of less than one +ten-thousand millionth part of a grain of chlorine in one tenth of a cubic +centimeter of distilled water by this process. The same kind of action +occurs with other electrolytes, but requires larger proportions of +dissolved substance.</p> + +<div class="footnote"><p><a name="Footnote_7_7" id="Footnote_7_7"></a><a class="label" href="#FNanchor_7_7">[7]</a> As one part of chlorine in 17,612 million parts of water had +no visible effect, and one in 17,000 million had a distinct effect, the +influence of the difference, or of one part in 500,000 millions, has been +detected.</p></div> + +<p>As the degree of sensitiveness of the method appears extreme, I add the +following remarks: The original solution of washed chlorine in distilled +water was prepared in a dark place by the usual method from hydrochloric +acid and manganic oxide, and was kept in an opaque, well-stoppered bottle +in the dark. The strength of this liquid was found by means of volumetric +analysis with a standard solution of argentic nitrate in the usual manner. +The accuracy of the silver solution being proved by means of a known +weight of pure chloride of sodium. The chlorine liquid contained 2.3 +milligrammes or 0.03565 grain of chlorine per cubic centimeter, and was +just about three-fourths saturated.</p> + +<p>One tenth of a cubic centimeter of this solution ("No. 1") or 0.003565 +grain of chlorine was added to 9.9 c. c. of distilled water and mixed. One +cubic centimeter of this second liquid ("No. 2"), or 0.0003565 grain of +chlorine, was added to 99 c. c. of water and mixed; the resulting liquid +("No. 3") contained 0.000003565 grain of chlorine per cubic centim. To +make the solutions ("No. 4") for exciting voltaic couple, successive +portions of <sup>1</sup>⁄<sub>10</sub> or <sup>1</sup>⁄<sub>20</sub> c. c. of "No. 3" liquid were added to 900 cubic +centimeters of distilled water and mixed.</p> + +<p>I have employed the foregoing method for examining the states and degrees +of combination of dissolved substances in electrolytes, and am also +investigating its various relations.</p> + +<hr class="ChapterTopRule" /> + +<h2><a name="THE_WIMSHURST_INFLUENCE_MACHINE" id="THE_WIMSHURST_INFLUENCE_MACHINE"></a>THE WIMSHURST INFLUENCE MACHINE.</h2> + +<p>In our last number we gave illustrations of this machine, in which 12 +plates 30 in. in diameter are used, and sparks nearly 14 in. in length are +obtained. The engraving, from photographs, shows sparks 13½ in. in length, +obtained from this machine.</p> + +<div class="figcenter" style="width: 300px;"> +<img src="images/i027.png" width="300" height="196" alt="Arc tracks." title="" /> +<span class="caption">DISCHARGE FROM THE WIMSHURST INFLUENCE MACHINE.</span> +</div> + +<hr class="ChapterTopRule" /> + +<h2><a name="SANITATION_IN_MASSACHUSETTS" id="SANITATION_IN_MASSACHUSETTS"></a>SANITATION IN MASSACHUSETTS.</h2> + +<p>This subject was prominently considered by Dr. H. P. Walcott, of Boston, +in his address on state medicine, at the meeting of the American Medical +Association recently. The vital statistics of Massachusetts, he said, +showed a declining death rate for the last thirty-six years, under the +influence of state sanitation. The most marked decrease had been observed +in the mortality from zymotic diseases; there had been a less decided +reduction of that from constitutional diseases; that from local diseases +had increased; and that from mental diseases and from violence had +remained stationary. In 1876 there was not a single death from small-pox. +Typhoid fever had diminished most in cities having a good system of +sewerage and water supply, and least in towns without such improvements. +Diphtheria, which reached its maximum in 1877, had since declined, until +it now caused only one per cent. of the total mortality. Ovariotomy saved +more lives than any other surgical operation, but, taking Somerville as a +basis of calculation, the ascertained results of preventive medicine had +saved more lives in ten years, among thirty thousand people, than +ovariotomy would save in the same time among two millions. Great attention +was given to small-pox, which had killed but 5,500 persons in +Massachusetts in thirty-six years, and to cholera, which had destroyed +only 2,000; but too little heed was given to scarlet fever, with its +mortality of 37,000, and to typhoid fever, with its mortality of +45,000.—<i>N. Y. Med. Jour.</i><!--028.png--></p> + +<hr class="ChapterTopRule" /> + +<h2><a name="THE_CARE_OF_THE_EYES8" id="THE_CARE_OF_THE_EYES8"></a>THE CARE OF THE EYES.<a name="FNanchor_8_8" id="FNanchor_8_8"></a><a href="#Footnote_8_8" class="fnanchor">[8]</a></h2> + +<div class="c3">By Prof. <span class="smcap">David Webster</span>, M.D.</div> + +<h3>SPECTACLES.</h3> + +<p>A vast amount of popular misapprehension and prejudice exists as to the +use of spectacles. Many persons who need them object to wearing them for +various reasons. Some fear that it will lead their friends to suspect that +they are getting old. Others think it will cause them to be suspected of +wishing to appear learned or cultured. Some persons do not want to begin +to wear them lest, having acquired the habit, they may not be able to +leave them off or to see well without them. Others again object to glasses +only on account of their inconvenience. I have personally met with many of +all these classes of persons, but I have frequently heard of another class +that I have never met with, namely, those who do not need glasses, but who +wear them just for effect and to attract attention. Now, the simple truth +is that there are just two good reasons for wearing spectacles, and only +two. One is that we may see better, the other is that our eyes may be +relieved of strain. Often both these reasons are combined in the same +case. Many children begin to be near-sighted after they have attended +school a few years. They first find it out by observing that they cannot +see letters or figures on the blackboard as far as the other children. +They can use their eyes as much as they want to without fatigue or +blurring, or smarting, or burning, or itching, or pain in the eyes, or +headache. In short, they show no symptoms of eye strain. They simply do +not see distant objects distinctly. Such children should be fitted with +glasses at once that will enable them to see as well as others at a +distance, and these glasses should be worn constantly. The child should be +instructed to take them off only when necessary to wipe them or to wipe or +bathe the eyes and on going to bed. The sooner the eyes get accustomed to +them the less likely is the near-sightedness to increase. Moreover, the +child who sees clearly only a few feet away from him loses a very +important part of his education. Our eyes gather information for us when +we are least thinking of it, by taking cognizance of the many objects that +come within our field of vision just as our ears gather material for the +proper development of our minds in listening to general conversation or to +the sounds of nature and of busy life about us. It is the duty of every +one to make the best possible use of the faculties the Creator has +bestowed upon him. The near-sighted person who does not have his vision +corrected by glasses fails in the performance of this duty.</p> + +<div class="footnote"><p><a name="Footnote_8_8" id="Footnote_8_8"></a><a class="label" href="#FNanchor_8_8">[8]</a> Continued from <span class="smcap">Supplement</span>, No. 647, page 10342. +</p><p> +From a paper by David Webster. M.D., professor of ophthalmology in the New +York Polyclinic and surgeon to the Manhattan Eye and Ear Hospital, New +York.</p></div> + +<p>Again, the time comes in the life of every one who is not near-sighted, +and who lives to a good old age, when he cannot see near objects well +without glasses. Between the ages of 40 and 50, the crystalline lenses of +his eyes having hardened along with the other tissues of his body, he +finds it impossible to focalize as he used to. He holds his book farther +and farther away from his eyes, and finally he finds that he cannot read +fine print at all, or without straining his eyes. Then he must accept the +unpleasant fact that he is getting old-sighted, and if he wishes to use, +and not abuse, his eyes, he must get glasses to take the place of his lost +accommodation and with which he can read easily. Some persons who are +near-sighted in one eye and far-sighted in the other never need glasses, +but always do their reading and other near work with the near-sighted eye +and their distant seeing with the far-sighted eye. I believe I read a long +time ago, in an article by himself in the New York <i>Ledger</i>, that this was +the case with the late Rev. Henry Ward Beecher. But the vast majority of +persons who wear glasses, both for the distance and for the near, can see +quite as well without them. They do not wear them in order to be able to +see, but in order to have the strain removed from their eyes, and to be +relieved from the many disagreeable symptoms, both direct and reflex, that +result from eye strain.</p> + +<h3>FOCALIZATION.</h3> + +<p>The act of focalization is a muscular act and requires an effort, an +output of nervous energy, just as much in +<!--029.png-->proportion as any other +muscular act, such as lifting a weight or shoving a saw or a jack plane. +The eye that is normally shaped forms pictures of objects, more than a few +feet distant, on its back wall without any muscular effort, and has to +focalize only when engaged in near work. But the oversighted eye is +compelled to do this extra work all the time, except when closed. If it +did not focalize, it would see indistinctly. This it refuses to do, +independently of any volition on the part of its owner. The eye that <i>can</i> +see distinctly <i>will</i> see distinctly, no matter how great the strain, and +this by a volition apparently entirely its own. The results are headache, +vertigo, nausea, nervousness, irritability, and other disagreeable reflex +conditions, besides the pain and inflammation, and other symptoms +manifested in the eyes themselves. Of course, the only remedy in such +cases is glasses, and these glasses should be carefully selected by a +competent person, and should be worn as much of the time as is necessary +to relieve the eye strain. I find in <i>Taggart's Times</i>, February 5, 1888, +the following: "A French philosopher has said that a man who wears +gold-bowed spectacles always admires himself, and it would seem as though +spectacles were becoming a sort of badge of distinction, since young and +old who have the slightest excuse for using them put them on.</p> + +<h3>HEADACHE.</h3> + +<p>"When one suffers from headache, he is told that he overstrains the nerves +of the eyes, and must relieve this by the use of spectacles. When things +dance before the sight, the cure for that is also spectacles; and when +tired with close attention to work, the cure for wearied eyes is not rest, +but spectacles.</p> + +<p>"People who live much out of doors are usually very keen-sighted, owing +probably to the ever-varying impressions made on the eyes, and this might +reasonably suggest that the proper relief for a great many eye troubles +would be a change from overwork."</p> + +<p>I can only say that the person who wrote it seems not only to be +prejudiced against glasses, but to know very little of the anatomy and +physiology of the eye. The fact is that oversighted and astigmatic eyes, +needing glasses to relieve the constant and severe strain upon the +accommodative muscular apparatus, are benefited by rest and by change of +air and occupation only to a limited degree. Real rest for such eyes is +possible only from the use of glasses. Moreover, it is not possible for +all who suffer from fatigue of the eyes to take the time for rest. It is +necessary for many to use their eyes daily and almost constantly in order +to make a living for themselves and for those dependent upon them. There +is much more good sense in the paragraphs which follow and which are +extracted from the same article.</p> + +<p>"It is not surprising that so many school children suffer with weak eyes +when we consider the conditions under which they are forced to use them. +The very fact that the light in many school rooms is twice strained +through glass partitions before it penetrates the inside rooms is in +itself a severe test of sight. The preponderance of sash-wood over the +panes of glass is anything but propitious to clear seeing. With heads bent +over desks doing arithmetical examples, or studying the fine printed +school books, or reading their own imperfect handwriting from which many +of the lessons must be learned, the only wonder is that all the little +ones are not purblind before they reach the grammar schools.</p> + +<h3>FLUFFY BANGS.</h3> + +<p>"But this is not all. Girls wear long and fluffy bangs, intercepting the +sight, and both boys and girls seldom bathe their faces with clear cold +water. In the matutinal face washing the eyes are usually closed, while a +wet towel is delicately passed over the eyelids. Few persons can bear the +pain of opening their eyes wide in a basin of cold water, yet Mr. A. M. +Spangler told, in his interesting lecture on Nassau, how the native +population would dive to the bottom of the sea and bring up shells, +sponges, etc., that had been pointed out to them by curious visitors +through a sea glass. Not only men divers, but also little boys and girls +could keep their eyes open in the water and search for cents which had +been thrown in for them to pick up. This shows that even salt water is not +injurious to eyes accustomed to it, and that habit makes the eye +unnaturally sensitive."</p> + +<p>As to the statement that "people who live much out of doors are usually +very keen-sighted," it is an expression of a popular idea, but, like most +popular ideas, is true only to a limited extent. The fact is that persons +who do not live much out of doors generally use their eyes more for near +work, such as reading, sewing, drawing, etc., and hence are more likely to +develop near-sightedness. Persons living indoors who are not near-sighted +are able to see as well and as far as those who live outdoors. It is true +that the old sailor will recognize a ship in the horizon, or any other +distant object at sea, sooner than a landsman. But it is not because he is +any more "keen-sighted." It is because he knows just what to look for. He +has seen such objects amid similar surroundings a thousand times, and +recognizes them, even though his vision be considerably impaired by +disease. I have often found, on testing the vision of such persons, that +it was not more than one-half the normal, and yet they declared, and, I +believe, conscientiously so, that they could discern a ship at sea as far +as any one. A very large proportion of the North American Indians, who +live much out of doors, have poor sight from inflammatory diseases of +their eyes caused by exposure to smoke in their wigwams, and by contagious +eye diseases, the propagation of which is favored by their unsanitary +methods of living. But, no doubt, many of them can discern distant objects +upon the prairies and in the forests farther than their white brothers +because of their greater familiarity with the appearances of such objects.</p> + +<p>It seems to me that the practice of opening the eyes under water is not to +be specially recommended, except in cases of necessity. While many bear it +well, to others it is more or less painful and irritating. Moreover, +nature furnishes a fluid with which to wash the eyeballs, and applies it +herself. It is only necessary to keep the eyelids scrupulously clean, and +especially the edges of the eyelids where the eyelashes grow out. For +bathing the eyelids when uninflamed, nothing is better than pure cold +water. When the eyes become red and inflamed, the best domestic remedy is +salt and water, about a teaspoonful to the pint, and applied warm or cold, +or at whatever temperature seems most agreeable to the eyes in any +particular +case.<!--030.png--><span class="pagenum"><a name="Page_10353" id="Page_10353">10353</a></span></p> + +<h3>NO POULTICES.</h3> + +<p>Under no circumstances should poultices be applied to the eyes unless +ordered by a physician. I have seen many cases in which a simple +inflammation of the inside lining of the eyelids had been greatly +aggravated by bread and milk poultices, or tea leaves, bound upon the +closed eyelids and left on overnight. In fact, a distinguished professor +of diseases of the eye has formulated the results of his observations +thus: "Poultices spoil eyes."</p> + +<p>All patent eye washes, eye salves, and other remedies advertised to cure +all diseases of the eye should be avoided. Different diseases require +different remedies. What will benefit one may injure another. When one +gets something the matter with his eyes and resorts to the use of a patent +medicine for its relief, he is in danger of losing valuable time. He may +lose an eye from want of proper treatment at the outset of the disease. In +a great city like New York, every one may easily avail himself of the +services of the most skillful physician. If unable to visit them at their +offices and pay their fees, they may consult them at the numerous +dispensaries, hospitals, and medical schools and colleges, where it will +cost them nothing.</p> + +<h3>USE OF INFLAMED EYES.</h3> + +<p>A lesson that is very difficult for many of us to learn is that inflamed +eyes should not be used actively. Children with sore eyes should not be +allowed to go to school for two reasons. First, the use of their eyes in +reading will prevent or retard their recovery. Secondly, sore eyes are +usually communicable, and one such child may infect a whole school. It is +highly important that all persons with inflamed eyes should use only their +own wash basins, towels, and handkerchiefs, and so avoid spreading the +disease. We not infrequently see a catarrhal inflammation of the eyes run +through a whole family. Of course, they catch it one from another, and, as +there is no disease of the eye which is, like measles, or scarlet fever, +or smallpox, communicable through the air, such spread of the disease +might easily be prevented by proper care of the person first affected. +Persons whose eyes are sensitive to light should not be kept in dark +rooms, which are always unhealthy. They may have their eyes protected by +shades or by smoke colored glasses, but should keep them open and exposed +to the air, and should remain out of doors as much as possible.</p> + +<h3>EFFECT OF ALCOHOL AND TOBACCO UPON THE EYES.</h3> + +<p>I must not close without warning my hearers against the baneful effects of +alcohol and tobacco upon the eyes. It is not uncommon for the eye surgeon +to meet with persons who have become partially blind from the effects of +these poisons upon their optic nerves. Of course, only a small proportion +of those who use alcohol and tobacco to excess are affected in this way, +but this renders it none the less certain that impaired sight is one of +the dangers that we may avoid by abstaining from the use of these +unnecessary and poisonous luxuries.</p> + +<hr class="ChapterTopRule" /> + +<h2><a name="TUMORS_OF_THE_BLADDER" id="TUMORS_OF_THE_BLADDER"></a>TUMORS OF THE BLADDER.<br /> +DIAGNOSED BY MEANS OF THE ELECTRO-ENDOSCOPIC CYSTOSCOPE.</h2> + +<div class="c3">By Dr. <span class="smcap">Max Nitze</span>.</div> + +<p>In the following lines I wish to direct the attention of my English +<i>confreres</i> to the value of the electro-endoscopic mode of examination of +the male urinary bladder, invented by me. I believe I could not have +chosen a more suitable theme for that purpose than a short report of the +bladder tumors diagnosed by me cystoscopically; for the diagnosis of these +new formations offers the greatest difficulty, and in most cases it has +been impossible till now to prove their existence with accuracy without +digital exploration of the bladder. By the new method of cystoscopical +examination the conditions have entirely changed. One look into the +bladder, illuminated as if by daylight, is generally sufficient to afford +means for forming an opinion of all the questions coming into +consideration—viz., size, form, and site of the tumor. The accompanying +diagrams (Figs. 1, 2, 3, 4) may give an idea of the appearances which the +different forms of bladder tumors present endoscopically. I regret that +they cannot show the brightness of the light by which one sees the tumors +during examination. The celebrated Vienna specialist, V. Dittel, is right +in saying that "they offer sometimes truly charming pictures;" especially +certain kinds of villous tumors, whose long slender villi floating in the +liquid often present a splendid appearance. The following are the cases +cystoscopically diagnosed by me.</p> + +<div class="figright" style="width: 300px;"> +<img src="images/i031-1.jpg" width="300" height="300" alt="View through cystoscope." title="" /> +<span class="caption"><span class="smcap">Fig. 1.</span></span> +</div> + +<p><i>Case 1.</i>—A man, aged fifty-five, under the care of Dr. Ch. Mayer, +suffered from attacks of hæmaturia for thirty years. During the last six +years he has had dysuria and inability to empty the bladder completely. +The patient had been examined by the sound repeatedly by eminent surgeons +and specialists, but none could give a certain diagnosis. On Nov. 11, +1886, I undertook the cystoscopic examination. I found on the anterior +wall of the bladder a puffy swelling covered with white masses of mucus. +(See Fig. 1.) The trigone was covered by a mass consisting of pointed +papillæ. On account of the weakness of the patient extirpation was +impossible. The patient became weaker +<!--031.png-->and weaker, and died in June, 1887. +The post mortem examination showed the internal orifice of the urethra +surrounded by a swelling representing a continuous tumor as large as a +small apple. It was found that the instrument had penetrated through the +middle of this swelling, which bled easily on pressure. In spite of this, +the clearness of the picture was not interfered with in the least.</p> + +<div class="figright" style="width: 300px;"> +<img src="images/i031-2.jpg" width="300" height="291" alt="View through cystoscope." title="" /> +<span class="caption"><span class="smcap">Fig. 2.</span></span> +</div> + +<p><i>Case 2.</i>—A man, aged fifty, was obliged to exert a strong pressure in +order to empty the bladder. The flow of urine often stopped. He himself +introduced a catheter, and on withdrawing it a piece of villous tissue was +found. On Dec. 10, 1886, I saw, on cystoscopical examination, directly and +immediately over the internal orifice of the urethra, a villous swelling +hanging from the anterior wall of the bladder. (See Fig. 2.) On Jan. 15, +1887, extirpation of the tumor by means of the high section was performed +by Professor v. Bergmann. The size of the tumor (which was as large as a +pigeon's egg) and its position corresponded exactly to the endoscopic +picture. The patient recovered.</p> + +<div class="figright" style="width: 300px;"> +<img src="images/i031-3.jpg" width="300" height="299" alt="Fig. 3." title="" /> +<span class="caption"><span class="smcap">Fig. 3.</span></span> +</div> + +<p><i>Case 3.</i>—A patient under the care of Professor Madelung, aged +fifty-five, suffered from attacks of hæmaturia. Examination by sound and +rectal palpation had given me negative results. On Feb. 20, 1887, +cystoscopical examination was made. On the left side of the trigone a +tumor with a broad base was seen, which resembled somewhat a strawberry in +size and form. (See Fig. 3.) On March 1, Professor Madelung undertook the +extirpation of the tumor. The appearance corresponded exactly to the +cystoscopic picture. The patient recovered.</p> + +<div class="figright" style="width: 300px;"> +<img src="images/i031-4.jpg" width="300" height="299" alt="View through cystoscope." title="" /> +<span class="caption"><span class="smcap">Fig. 4.</span></span> +</div> + +<p><i>Case 4.</i>—This was a patient on whom Dr. Israel had performed the high +section a long time before, on account of a bladder tumor. The extent was +so great that only its most prominent part could be removed. The +microscopical examination proved the diagnosis of cancer. Quick healing +took place. The patient became free from pain, and the urine became clear. +In +<!--032.png-->order to see what had become of the remaining part, the cystoscopical +examination was undertaken on April 3. It was easy to see that the right +lateral wall was covered to an extent of from three to four centimeters +with thick masses of verrucous and fungiform excrescences. (See Fig. 4.)</p> + +<p>[We omit the description of the additional cases.]</p> + +<p>The above shortly described fifteen<a name="FNanchor_9_9" id="FNanchor_9_9"></a><a href="#Footnote_9_9" class="fnanchor">[9]</a> cases of bladder tumors have been +diagnosed by me cystoscopically during the last sixteen months. This is a +proof, on the one hand, of the value of the cystoscopic examination; on +the other hand, of the fact that the new formations in question are not of +so rare occurrence as has been hitherto thought. I would like to emphasize +that the important results were often obtained under the most difficult +circumstances. In several cases the external orifice of the urethra was +found abnormally small; in others (Cases 8 and 11) the examination was +made during the occurrence of a continuous hemorrhage from the tumor; in +one case (Case 1) I introduced the instrument through the center of the +tumor, which bled on the slightest pressure. In spite of this the +appearances were seen satisfactorily. In the first case a post mortem +examination was made; in eight other cases (Cases 2, 3, 9, 10, 11, 13, 14, +and 15) the tumor was extirpated, seven times by the high section—in one +case, that of a woman, through the dilated urethra. In these nine cases +the endoscopic appearances were in every important respect confirmed in +the most perfect manner. In every case my opinion regarding the size, +position, and form was found to be correct. It is only in those cases +where the edges of the tumor overlap the short pedicle that the latter +cannot be observed. Besides, the relative good results of the operations +undertaken on account of the cystoscopic appearance may be emphasized. Of +the eight patients from whom the tumors had been extirpated, none died +from the result of the operation. Case 9 proved fatal on account of the +progressive extension of the growth. In the eleventh case there was a +recurrence, but the patient is still alive. Five patients (Cases 2, 3, 10, +13, 14) must be considered entirely cured. Case 15 is still under +treatment, and, as the conditions of the patient are at present (ninth day +after operation) in every way satisfactory, a complete recovery is +anticipated.</p> + +<div class="footnote"><p><a name="Footnote_9_9" id="Footnote_9_9"></a><a class="label" href="#FNanchor_9_9">[9]</a> The first eight cases are more fully described in the Arch. +fur Chirurgie, vol. xxxvi., Part 3 (Dr. Nitze, Beitrage zur Endoscopie der +mannlichen Harnblase). The full account of the last seven cases will be +published soon.</p></div> + +<p>Finally, on comparing the above cystoscopic appearances with the results +obtained by other methods of examination, it must be observed that the +examination of the urine, in most cases carefully made, had only in two +cases shown the presence of villous tissue, which in one instance was +brought out by the catheter. The rectal palpation, when made, had always +given negative results. Further, the examination by means of the sound had +been made in nine cases before the cystoscopic examination. In none of the +cases had the sound revealed the presence of a tumor (which in two had +attained the size of a small apple), although the examination was made by +most experienced surgeons and eminent specialists. Those cases show how +imperfect an instrument the sound is for the diagnosis of bladder tumors.</p> + +<p>Only one method can compare with the cystoscope in giving valuable +information regarding the size and nature of a bladder tumor—viz., the +digital exploration of the internal surface of the bladder after a +previous <i>boutonniere</i>, or the high section. The superiority of the +cystoscopic method over the latter, on account of the smaller amount of +inconvenience it causes the patient, need not be insisted on. The latter +involves a cutting operation not free from danger, as well as deep +narcosis, while the cystoscopic method is similar to a simple +catheterization.</p> + +<div class="figcenter" style="width: 434px;"> +<img src="images/i030.png" width="434" height="121" alt="Cystoscope." title="" /> +<span class="caption"><span class="smcap">Fig. 5.</span></span> +</div> + +<p>The accompanying diagram (Fig. 5) shows the instrument used by me for +cystoscopic examination. It has been made by the Berlin instrument maker, +Hartwig, according to my instructions. The source of the light (Mignon +lamp) is cemented in a silver capsule, which is screwed into the distal +end of the cystoscope. This instrument is superior to that made by Leiter, +the Vienna instrument maker, because of its greater simplicity in +construction, which allows the lamp to be easily replaced when necessary, +and also on account of the greater length of the shaft.</p> + +<p>I mention this because it differs from the explanation +<!--033.png--><span class="pagenum"><a name="Page_10354" id="Page_10354">10354</a></span>which +Mr. Fenwick +gave in his speech concerning my method of examination at the meeting of +the Medical Society of London on Jan. 23, 1888. I must also strongly +contradict Mr. Fenwick's statements concerning the share which he +attributed to the Vienna instrument maker in the construction of the +instrument. Leiter's connection with our instrument will be best explained +when I say that he had to buy the patent<a name="FNanchor_10_10" id="FNanchor_10_10"></a><a href="#Footnote_10_10" class="fnanchor">[10]</a> from me first in order to be +allowed to make the instrument. Leiter has had no share in those +peculiarities which characterize it as new. The introduction of the source +of light into the organ had been practically brought about, the optical +apparatus enlarging the view designed, the whole construction perfected, +the instrument had proved itself useful in examining patients, and had +been demonstrated by me in the Saechsisches Landes Medicinal Collegium +before Leiter had any idea of the new invention! Also the eventual +replacement of the first source of light (platinum wire) had been provided +for.<a name="FNanchor_11_11" id="FNanchor_11_11"></a><a href="#Footnote_11_11" class="fnanchor">[11]</a> Leiter has only made a few technical modifications on the +finished instrument. I protest most emphatically against the incorrect +explanations given by Mr. Fenwick, and against every connection of +Leiter's name with my instruments. I hope to obtain in England the same +generous recognition of my labors in this field that has been accorded to +me in Germany.—<i>Lancet.</i></p> + +<div class="footnote"><p><a name="Footnote_10_10" id="Footnote_10_10"></a><a class="label" href="#FNanchor_10_10">[10]</a> Deutsche Patentschrifte, No. 6, 853.</p></div> + +<div class="footnote"><p><a name="Footnote_11_11" id="Footnote_11_11"></a><a class="label" href="#FNanchor_11_11">[11]</a> Ibid.</p></div> + +<hr class="ChapterTopRule" /> + +<h2><a name="PAPILLOMATOUS_TUMOR_OF_THE_BLADDER_DEMONSTRATED_BY_MEANS_OF_LISTERS" +id="PAPILLOMATOUS_TUMOR_OF_THE_BLADDER_DEMONSTRATED_BY_MEANS_OF_LISTERS"></a>PAPILLOMATOUS +TUMOR OF THE BLADDER, DEMONSTRATED BY MEANS OF LISTER'S +ELECTRO-CYSTOSCOPE.</h2> + +<div class="c3">By F. N. Otis, M.D., Clinical Professor, College of Physicians and +Surgeons, New York.</div> + +<p>A. G——, aged twenty-three, United States; single; barber.</p> + +<p>The young man was referred to me by his former medical attendant, March +16, 1883. His urine was found to be slightly but distinctly tinged with +blood, and contained some small clots as well as some pus and mucus. He +complained of exquisite pain on urination, increased at the close, +recurring every half hour. Through examination per rectum (<i>a posteriori</i>) +unusual tenderness was found. Distinct increase in the density and +thickness of the right inferior section of the bladder was recognized by +the bimanual touch; a catheter was introduced, and three ounces of bloody +urine removed. The bladder was then irrigated gently with a saturated +solution of boric acid until the fluid returned clear. The catheter was +then withdrawn, leaving about four ounces of the solution, of a +temperature of 80°, in the bladder, as a preparation for its examination +by the electro-cystoscope of Lister. The required current was furnished by +the small six-cell battery of the Galvano-Faradic Co. The cystoscope was +then introduced into the bladder, and the current turned on. The +illumination was complete. Through the slightly rosy medium the small +blood vessels in the bladder mucous membrane were distinctly seen. On the +right side a deep red, granular-looking mass, with a wavy outline, was +then distinctly observed, covering about one-fourth of the cystoscopic +field. This appearance was verified by Drs. Abbe, Bangs, and W. K. +Otis—the unanimous opinion being that it represented a papillomatous +growth, to some extent covered by coagulated blood. Two days later a +similar examination was made, under the influence of an anæsthetic, which +corroborated the previous observations in every particular. (See +illustration.)</p> + +<div class="figright" style="width: 300px;"> +<img src="images/i033-1.png" width="300" height="263" alt="Traveling up urethra, scope views +tumor from the inside of the bladder." title="" /> +<span class="caption">DIAGRAM OF BLADDER, SHOWING LOCATION OF TUMOR +AND POSITION OF CYSTOSCOPE.</span> +</div> + +<p>Some small filaments were subsequently removed with the lithotrite, but on +microscopical examination nothing of diagnostic importance was discovered. +From lack of the capacity of the bladder, the field was necessarily +limited, nevertheless, a very excellent view of the tumor could be +obtained. This is shown in the illustration, from a sketch made at the +time of the first examination. It represents the position of the tumor and +cystoscope when the best view of it was obtained.</p> + +<p>On the following Monday the patient entered St. Luke's Hospital, and was +operated upon by my associate, Dr. L. B. Bangs, Dr. Charles McBurney +assisting. The high operation was performed, and the bladder being +examined by means of an electric light, introduced through the suprapubic +incision, the diagnosis made by the cystoscope was verified in every +particular. The growth was then removed, as far as possible, with the +scissors, and the surface cauterized with the Paquelin cautery. At the +present writing the patient is going on toward a satisfactory recovery. +The pathological examination made by Dr. Frank Ferguson, pathologist of +St. Luke's Hospital, showed the neoplasm to be a simple papilloma.</p> + +<p>This case is deserving of especial interest as being the first tumor of +the bladder diagnosticated in this country by means of the cystoscope, and +verified by subsequent +<!--034.png-->operation, and adds one more to the list of +sixteen cases so made out by foreign observers, and two by Dr. Fenwick, of +England. In this instance the instrument deserves particular credit, as +other methods had completely failed in the practice of competent +observers.</p> + +<p>This consists of a metal tube, about seven inches long, of a caliber of 22 +French, having at the proximal end a funnel shaped ocular opening; at the +distal, a short beak, similar to that of the catheter coudé. A window of +rock crystal is set in the end of this beak, behind which a small electric +lamp, controlled by a switch at the ocular end, is placed. A rectangular +prism, the hypothenuse plane of which is silvered, is placed in the end of +the straight portion of the tube, its superior face being seen just +anterior to the angle formed by the beak. The distended bladder is +illuminated by the electric lamp, the rays reflected from its wall falling +on the prism experience total reflection, an inverted image being formed +within the tube. The size of the field thus obtained is greatly increased +by means of a telescope introduced into the tube. The image seen through +the cystoscope is an inverted image, but right and left are not +transposed.</p> + +<div class="figcenter" style="width: 478px;"> +<img src="images/i034.png" width="478" height="117" alt="The cystoscope." title="" /> +<span class="caption">THE CYSTOSCOPE.</span> +</div> + +<p>There can be no question as to the great prospective value of the +electro-cystoscope in diagnosis of many difficulties to which the bladder +is subject. A variety of foreign bodies have already been reported as made +out by use of this instrument. The locality, size, and color of vesical +calculi have been demonstrated in my own experience. In one instance two +stones were seen where only one had been previously found, but this of +course might with care have been effected by means of the lithotrite. But +it is in the diagnosis of the tumors, and encysted or impacted calculi, +that the most essential service may be anticipated from the use of the +cystoscope. The orifices of the ureters are quite readily brought into the +cystoscopic field, and it is more than probable that (perhaps through the +introduction of some clear fluid with which blood does not readily +mingle—glycerine, for instance) the true source of a previously doubtful +hæmaturia will be demonstrated.—<i>Medical Record.</i></p> + +<hr class="ChapterTopRule" /> + +<h2><a name="DISTANCE_AND_CONSTITUTION_OF_THE_SUN" +id="DISTANCE_AND_CONSTITUTION_OF_THE_SUN"></a>DISTANCE AND CONSTITUTION OF THE SUN.</h2> + +<p>So many queries about the solar system, or the members of it, have come +recently to the attention of those in charge of this journal, from various +sources, that it is thought best to make a brief statement of the present +state of knowledge that astronomy has of the solar neighborhood in which +we live.</p> + +<p>Naturally we begin with the sun, and the oldest and most important problem +which the study of this body offers is the determination of its distance +from the earth in terrestrial units of measure. This distance is important +because the knowledge of all the phenomena of all the heavenly bodies, +except those of the moon, depend directly or indirectly on its value. The +problem of the sun's distance is difficult because the data given for +determining it are insufficient to enable the astronomer to apply the +principles of trigonometry directly to it. He is, therefore, compelled to +use indirect methods of solution, which, at best, give only approximations +to the true distance, arising chiefly from small errors in observation, +which, at the present time, seem unavoidable. A familiar illustration will +make our meaning clear. The knowledge we have of the sun's distance +depends on the accurate measurement of a small angle formed by drawing two +lines from a point at the sun to the extremities of the earth's radius. +That angle is called the sun's parallax. Ptolemy thought that this angle +was 3′ of arc, but we now know that its value is very near 8.80" of arc, +and that the error of this amount from the true angle probably is not more +than 0.02". To measure this small angle has been the astronomer's great +trouble since the time of Aristarchus, and he does not yet know its value +accurately. His problem is like that of a surveyor attempting to measure a +ball, whose real diameter is one foot, at the distance of 4.4 miles +nearly; and unless he can determine the diameter of the ball so that he +shall not be uncertain in his measure to the amount of 0.03 of an inch, +his work will not add anything useful to present knowledge.</p> + +<p>If we suppose the angle of parallax to be known, the computation of the +distance of a celestial body is easy. Multiply earth's radius by 206,265 +(seconds of arc in the unit radius), and divide the product by the angle +of parallax in seconds of arc. The mean equatorial radius of the earth, as +given in Clark's Geodesy, is 3963.3 English miles. The sun's distance for +a parallax of 8.78" would be</p> + +<pre> +206,265" × 3963.3 +————————————————— = 93,108,000 miles. + 8.78" + +For parallax of 8.80" = 92,897,000 miles. +For parallax of 8.82" = 92,686,000 miles. +</pre> + +<p>The range of error in parallax, as here given, is 0.04", and the change of +the distance of the sun in allowing for this error is nearly half a +million of miles. If 8.80" be the assumed parallax, with ± 0.02" as +probable error, then the uncertainty of the sun's distance is still nearly +a quarter of a million of miles.</p> + +<p>So far astronomers are pretty generally agreed, unless it be in the value +of the earth's radius used above. In his excellent work, entitled "The +Sun," we notice that Professor Young gives 3,962.72 English miles as the +"latest and most reliable determination" (page 22), while he seems to use +Bessel's value of 3,962.80 in obtaining 92,885,000. This may be because +the last named value is still in most general use, though less accurate +undoubtedly than that of Clarke.</p> + +<p>Since the transit of Venus, of 1874, the determination of the solar +parallax has not been very much improved. +<!--035.png-->The transit of 1882, so far as +known, has given surprisingly discordant results, and probably they will +be of very little service in improving our knowledge of the distance of +the sun. In the midst of all this uncertainty of late work, in ordinary +methods two ways of studying the problem show results almost exactly +alike. They are obtained from late improved measures of the velocity of +light, and from measures by the heliometer. The parallax from these +sources is 8.794". The Brazilian results of transit of Venus for 1882, by +Wolf and Andre, recently published, make the parallax 8.808". The American +reductions for the last transit are not yet completed.</p> + +<p>From the above brief statement of results, it seems that the value of the +solar parallax is likely to be a trifle under 8.80", rather than above it, +making the distance of the sun probably very near 93,000,000 miles.</p> + +<p>The next most important problem pertaining to the sun is its constitution, +which is usually considered under four heads:</p> + +<p>1. The central portion, thought to be made up chiefly of intensely heated +gases.</p> + +<p>2. That part which is seen by the aid of the telescope, called the +photosphere, consisting of a "shell of luminous clouds formed by the +cooling and condensation of the condensible vapors at the surface where +exposed to the cold of outer space." (Young.)</p> + +<p>3. Outside of the photosphere is a shallow stratum, called the +chromosphere, "composed mainly of uncondensible gases (conspicuously +hydrogen) left behind by the formation of the photospheric clouds, and +bearing something the same relation to them that the oxygen and nitrogen +of our own atmosphere do to our own clouds." (Young.) And—</p> + +<p>4. The corona, which is the beautiful halo seen, with the naked eye, +outside of all, during the time of a total eclipse of the sun. This +curious halo with all its streamers and rifts is thought to be composed +chiefly of an incandescent material, in a far more attenuated state than +that of hydrogen, the rarest gas known, because it yields freely in the +spectroscope a certain line, 1474 K, which most agree can mean nothing +else, although no one knows what the gas or metallic vapor is. Hydrogen is +also found in the corona extending to the height of 600,000 miles above +the photosphere, and possibly 1,200,000 miles. Suspended in this mixture +of vapors, and "falling into, or projected from, the sun is a large +quantity of solid or liquid material, which is at such a temperature as to +be self-luminous. It is this which yields the continuous spectrum, free +from dark lines.</p> + +<p>"Besides these components in the outer envelope, there is present matter +which reflects or diffuses light much as our own atmosphere does.</p> + +<p>"To this is attributed the partial radial polarization of the corona. The +streamers and rifts indicate matter repelled, in various quantities, from +the sun by forces which may be electrical." (Hastings.)</p> + +<p>These are the views advanced by astronomers and physicists, as theories or +working hypotheses, until something better or more certain can be known. +They are not held as facts by any, because of insufficient proof to +establish them as such, and because there are very grave objections to +some of them which are at present unanswerable.</p> + +<p>For example, the spectroscope shows that the gaseous pressure at the limit +of the chromosphere is very small, although that is at the base of an +atmosphere from 600,000 to 1,200,000 miles deep, and under the influence +of a force of gravity more than twenty-seven times as great as that in +action at the surface of the earth.</p> + +<p>Optically, the atmosphere of the earth ceases at a height of forty-five +miles, but bodies at twice that altitude, moving at the rate of +twenty-seven miles per second, meet resistance of air enough to render +them incandescent almost instantly. But the evidence seems clear that, far +within the corona, the resistance to moving bodies is much less than in +our atmosphere at a height of sixty miles. The great comet of 1882 passed +through the coronal atmosphere within 300,000 miles of the sun, with a +velocity one hundred and eighty times that of the earth in its orbit. The +comet was not stopped, nor destroyed, nor its orbit disturbed, as +subsequent observations showed. The same thing was true, so far as known, +of the comet of 1843, which passed still nearer the solar surface. These +facts are troublesome to explain on the hypothesis of a coronal +atmosphere.</p> + +<p>Still further: if the sun be surrounded by a gaseous envelope, its +density, as aforesaid, ought to diminish from the solar surface outward to +its upper limits; but the fact is, the material of 1474 K line always +appears in the spectrum of chromosphere, which would seem to indicate, by +its place, that it is as much more dense than hydrogen as is magnesium +vapor, or even the vapor of iron. But the evidence of the spectroscope +makes this 1474 K material far less dense than that of hydrogen, and this +is a contradiction that is very troublesome to the student of solar +physics.</p> + +<p>In studying the polarization of the light of the corona, it is clear that +the amount of polarized light reflected from a particle at the surface of +the sun is nothing, "because the luminous source there is a surface with +an angular subtense of 180°;" hence polarization of the corona near the +limb of the moon ought to be small, farther away, larger. But observation +shows that the contrary is true, <i>i. e.</i>, the percent. of polarized light +increases as the corona is observed nearer the limb of the moon during +totality.</p> + +<p>These are a few of the difficult questions that stand in the way of +accepting the foregoing theories as facts pertaining to, or well grounded +knowledge of, the constitution of the sun. They are by no means all, or +possibly the most important ones. They are certainly among those that are +receiving very general attention at the hands of physicists at the present +time.—<i>Sidereal Messenger.</i> +<!--036.png--><span class="pagenum"><a name="Page_10355" id="Page_10355">10355</a></span></p> + +<hr class="ChapterTopRule" /> + +<h2><a name="CHANGES_IN_THE_STELLAR_HEAVENS" id="CHANGES_IN_THE_STELLAR_HEAVENS"></a>CHANGES IN THE STELLAR HEAVENS.</h2> + +<div class="c3">By <span class="smcap">J. E. Gore</span>, F.R.A.S., Honorary Associate and Vice-President of the +Liverpool Astronomical Society.</div> + +<p>If we look up at the starry heavens on a clear, moonless night, all seems +still, lifeless, and devoid of energy and motion. All of us are—or at +least should be—familiar with the apparent diurnal motion of the star +sphere, caused by the actual rotation of the earth on its axis, and with +the slower annual motion, due to the earth's revolution round the sun, +which brings different constellations into view at different seasons of +the year. These motions, due to the great and universal law of +gravitation, discovered and so ably expounded by the famous Sir Isaac +Newton, are of course wonderful and orderly in their regularity, and bear +silent testimony to the amazing power, majesty, and goodness of a great +and glorious Creator. There are, however, other motions and changes, even +still more wonderful, going on in the depths of space, which, though +unperceived by the ordinary observer, have been revealed to the eye and +contemplation of the astronomer by the accurate instruments and methods of +research which modern science has placed at his disposal. Some accounts of +these marvelous discoveries may prove of interest to the reader. The +"fixed stars" are so called because they apparently hold a fixed position +with reference to each other on the concave surface of the celestial +vault, and do not, as far as the unaided eye can judge, change their +relative positions as the planets do. Many stars have, however, what is +technically called a "proper motion," which, though of course very minute, +and only to be detected by the aid of refined and accurate instruments, +yet accumulate in the course of ages, and sensibly alter their position in +the sky. The largest "proper motion" hitherto detected (about seven +seconds of arc per annum) is that of a small star in the constellation +Ursa Major, known to astronomers as No. 1830 of Groonbridge's catalogue. +It has been calculated that this star is rushing through space with the +amazing and almost inconceivable velocity of 200 miles per second!—a +velocity which would carry it from the earth to the sun in about 5½ days +and to the moon in 20 minutes! The well-known double star 61 Cygni has a +proper motion of about five seconds of arc per annum, both components +moving through space together. This is, as far as yet known, the nearest +star to the earth in the northern hemisphere. Its parallax, as determined +by Sir R. S. Ball, is 0.4676 of a second of arc, and by Prof. Pritchard +(by photography) 0.43 of a second. Taking the mean of these values, its +distance from the earth would be about 460,000 times the earth's mean +distance from the sun, and its actual velocity about 33 miles per second. +This is, of course, the motion at right angles to the line of sight, but +as it may also have a motion <i>in</i> the line of sight, either to or from the +eye, its real velocity is probably greater than this. The remarkable +triple star 40 Eridani has a proper motion of four seconds annually. The +components are a fourth magnitude star accompanied by a distant double +companion which is a binary (or revolving double star), and accompanies +the bright star in its flight through space. There are two other faint and +distant companions which do not partake in the motion of the ternary star. +In the year 1864 the bright star was situated to the east of a line +joining these faint companions, but owing to its large proper motion it is +now to the west of them. In the case of the triple star Struve 1516, one +of the companions, which was to the west of the primary star in 1831, is, +owing to the proper motion of the bright star, now to the east of it. +Prof. Asaph Hall has found a parallax for 40 Eridani of 0.223 of a second. +This, combined with the observed proper motion, indicates an actual +velocity of about 54 miles per second. The star Mu Cassiopeiæ has also a +large proper motion. This star, about 4,000 years ago, must have been +close to Alpha Cassiopeiæ, and might have been so seen by the ancient +astronomers. The proper motion of the bright star Arcturus is so +considerable that in the course of about 30,000 years it will be near the +equator, and about 10° to the north of the bright star Spica, from which +it is at present separated by over 30°. These motions are of course those +which take place across the face of the sky. There are, however, motions +in the line of sight—both toward and from the eye—which have of late +years been revealed to us by the spectroscope, that wonderful instrument +of modern scientific research, by the aid of which several new metals have +been discovered, and which has been found so useful in chemical analysis, +and even in the manufacture of steel by the Bessemer process. Some years +since, Dr. Huggins, the eminent spectroscopist, found that the bright star +Sirius, "the monarch of the skies," was receding from the earth at the +rate of about 20 miles a second. Later observations at Greenwich +Observatory showed that this motion was gradually diminishing, and within +the last few years it has been found that the motion of recession has been +actually changed into a motion of approach, showing that this giant sun is +probably traveling in a mighty orbit round some as yet unknown center of +gravity.</p> + +<p>From a consideration of stellar proper motions, it has been concluded that +the sun—and therefore the whole solar system—is moving through space. +Recent investigations make the velocity of translation about 19 miles per +second (30 kilometers). The Greenwich observations place the "apex of the +solar motion" (as the point toward which the sun is moving is called) +between Rho and Sigma Cygni, while Dr. Huggins' results fix a point near +Beta Cephei. Both these points are near the Milky Way.</p> + +<p>There are other startling changes which have occasionally taken place +among the stars, and which must be looked upon almost in the light of +catastrophes. At rare intervals in the history of astronomy "temporary" or +"new" stars have suddenly blazed out in the heavens which were previously +either unknown to astronomers, or else were invisible, except in the +telescope. Some of these were of great brilliancy. In A.D. 173 a bright +star is recorded in the Chinese annals as having appeared between Alpha +and Beta Centauri (two bright stars in the southern hemisphere). It +remained visible for seven or eight months, and is described as resembling +"a large bamboo mat" (!)—a not very lucid description. It is worthy of +remark that there exists at the present time, close to the spot indicated, +an interesting variable star, which may possibly be identical with the +bright star of the +<!--037.png-->second century. Perhaps the most remarkable of these +wonderful objects was that observed by the famous Tycho Brahe in 1572, in +Cassiopeia, and called the "Pilgrim." It was so brilliant that it rivaled +the planet Venus at its brightest, and was visible at noonday. It remained +visible for over a year and then disappeared.</p> + +<p>A small star close to its recorded position has been observed in recent +years, and as it is thought to be slightly variable in its light, it may +possibly be identical with the long lost star of Tycho Brahe. Another new +star of almost equal brilliancy was observed in October, 1604, in +Ophiuchus, a few degrees southeast of the star Eta Ophiuchi. The planets +Mars, Jupiter, and Saturn were close together in this vicinity, and one +evening Mostlin, a pupil of Kepler's, remarked that a new and very +brilliant star had joined the group. When first seen it was white, and +exceeded in brightness Mars and Jupiter, and was even thought to rival +Venus in splendor! It gradually diminished, however, and in six months was +not equal in luster to Saturn; in March, 1606, it had entirely +disappeared. In 1670 a star of the third magnitude was observed by Anthelm +near Beta Cygni. It remained visible for about two years, and increased +and diminished several times before it finally disappeared. Flamsteed's +star, No. 11 of Vulpecula, has been supposed to be identical with +Anthelm's star, but Baily could not find that such a star exists. A small +star has, however, been observed at Greenwich within one minute of arc of +the place assigned to the temporary star by Picard's observations.</p> + +<p>Variability has been suspected in this faint star, and according to Hind +it has a hazy, ill-defined appearance about it, which may perhaps suggest +that it may be a small planetary nebula, similar to Schmidt's new star of +1876 in Cygnus. A small new star was observed by Hind in Ophiuchus on +April 28, 1848. When first noticed it was about the fifth magnitude. It +afterward rose to about fourth magnitude, but very soon faded away, and, +although still visible in the telescope, has become very faint in recent +years. A new star of seventh magnitude was found by Pogson on May 28, +1860, in the well-known star cluster known as 80 Messier in Scorpio. The +light of the star when first seen obscured the light of the nebula. On +June 10 the star had nearly disappeared, and the nebula was again seen +shining with great brilliancy.</p> + +<p>A very interesting temporary star—known as the "Blaze Star"—suddenly +appeared in Corona Borealis in May, 1866. It was first seen by the late +Mr. Birmingham, of Tuam, Ireland, on the night of May 12, when it was of +the second magnitude and equal in brightness to Alphecca, the brightest +star in the well-known "Coronet." It must have made its appearance very +suddenly, for Dr. Schmidt, the director of the Athens observatory, stated +that he was observing this region of the heavens a few hours previously, +and noticed nothing unusual. It rapidly diminished in brightness, and on +May 24 of the same year was reduced to nearly the ninth magnitude. It was +soon discovered that the star had been previously observed, and its place +registered by the great German astronomer, Argelander, as of magnitude 9½, +so that it is possibly a variable star of irregular period and fitful +variability. When near its maximum brilliancy, its light was examined by +Dr. Huggins with the spectroscope, which showed the bright lines of +incandescent hydrogen gas in addition to the ordinary stellar spectrum. +This implies that the great increase in its light was due to a sudden +outburst of hydrogen in the star's atmosphere. Some observers remarked +that when viewed with the naked eye it decidedly twinkled more than other +stars in the neighborhood, which rendered a correct estimate of its +relative brightness somewhat difficult. During the years 1866 to 1876, +Schmidt detected variations of light which seemed to show a period of +about 94 days, and these observations were confirmed by Schonfeld.</p> + +<p>On the evening of November 24, 1876, the late Dr. Schmidt, of Athens, +discovered a new star of the third magnitude, near Rho Cygni, in a spot +where he was certain that no bright star was visible four nights +previously. When first seen, it was somewhat brighter than Eta Pegasi. It +did not, however, remain long at this degree of brightness, but rapidly +decreased, and on November 30 had faded to fifth magnitude. It afterward +diminished very regularly, and in September, 1885, was estimated only +fifteenth magnitude with the 15½ inch refractor of Mr. Wigglesworth's +observatory. The star was examined with the spectroscope a few days after +its discovery, and showed bright lines similar to the "Blaze Star" in the +Northern Crown. One of these bright lines was believed to be identical +with Kirchhoff's No. 1474, which has been observed in the spectrum of the +solar corona during total eclipses of the sun. This star would seem to be +quite new, as there is no star in any of the catalogues in its position. +In September, 1877, it was examined with the spectroscope at Lord +Crawford's observatory, and its light was found to be almost entirely +monochromatic (of only one color), showing that the star "had changed into +a planetary nebula of small angular diameter" (!)</p> + +<p>In August, 1885, a star of about seventh magnitude made its appearance +close to the nucleus of the Great Nebula in Andromeda—a well-known object +visible to the naked eye, and which has been well called "the Queen of the +Nebulæ." The new star was independently discovered by several observers +toward the end of August, but seems to have been first certainly seen by +Mr. T. W. Ward, of Belfast, on August 19, at 11 P.M. At Greenwich +observatory the spectrum of the new star was found "of precisely the same +character as that of the nebula, <i>i. e.</i>, it was perfectly continuous, no +lines, either bright or dark, being visible, and the red end was wanting." +Dr. Huggins, however, on September 9, thought he could see from three to +five bright lines in its spectrum. The star gradually faded away, and on +February 7, 1886, was estimated only sixteenth magnitude in the 26 inch +refractor of the naval observatory at Washington. From a series of +measures by Prof. Asaph Hall he found "no certain indications of any +parallax," so that evidently the star and the nebula, in which it probably +lies, are situated at an immense distance from the earth. Prof. Seeliger +has investigated the decrease in light of the star on the hypothesis that +it was a cooling body, which had been suddenly raised to an intense heat +by the shock of a collision, and finds a fair agreement between theory and +observation. Anwers points out the similarity between this outburst and +the new star of 1860 in the +<!--038.png-->cluster 80 Messier, and thinks it very +probable that both phenomena were due to physical changes in the nebulæ in +which they occurred.</p> + +<p>With reference to the colors of the stars, some of the red stars have been +suspected to vary in color. The bright star Sirius is supposed—from the +description of it by ancient astronomers—to have been originally red, but +this seems very doubtful. The Persian astronomer Al Sufi, in his +"Description of the Heavens," written in the tenth century, describes the +well-known variable star Algol distinctly as a red star. It is now white, +and this is perhaps the best attested instance on record of change of +color in a bright star.—<i>Naturalists' Monthly.</i></p> + +<hr class="ChapterTopRule" /> + +<h2><a name="THE_COMMON_DANDELION" id="THE_COMMON_DANDELION"></a>THE COMMON DANDELION.</h2> + +<div class="c3">By <span class="smcap">Frederick Leroy Sargent</span>.</div> + +<p>In the various names which the dandelion has received, we see expressed, +for the most part, either a reference to the tooth-like recurved lobes of +the leaves, Fig. 1, or an allusion to the medicinal properties of the +plant. Thus, our English name is a modified form of the French <i>dent de +lion</i>, meaning lion's tooth, and in German we have the same idea expressed +in <i>Löwenzahn</i>. Fifty years ago this plant appeared in the botanies as +<i>Leontodon taraxicum</i>, the generic name being derived from the Greek +<i>leon</i>, lion, and <i>odons</i>, tooth, and the specific from the Greek +<i>tarasso</i>, to stir up, in reference to the effect of a dose. In later +works we find the genus <i>Leontodon</i>, including the "fall dandelion" (<i>L. +autumnale</i>), but not the true dandelion, which now appears in a genus by +itself under the name <i>Taraxicum Densleonis</i>. Here the specific name is +merely "lion's tooth" again, in Latin.</p> + +<div class="figleft" style="width: 72px;"> +<img src="images/i038.png" width="72" height="167" alt="Outline of leaf." title="" /> +<span class="caption"><span class="smcap">Fig. 1.</span></span> +</div> + +<p>Finally, in the latest works our plant is given as <i>Taraxicum officinale</i>, +since this has been found to be the name which, according to the rules of +botanical nomenclature, takes precedence of all others. An allusion to the +teeth is thus no longer retained, the only reference remaining being to +the plant's officinal use.</p> + +<p>To the majority of people the mention of the dandelion calls to mind not +so much its medicinal properties as its use for food. Although its +cultivation, either as a spring pot herb or as a salad with blanched +leaves, is comparatively modern, the wild plant seems to have been long +valued as a vegetable. There is reason to believe that the Romans made use +of it as a pot herb, and Chinese writers of the fourteenth century mention +its being eaten in their country, although there is no evidence of +cultivation at that time.</p> + +<p>There are but few of our flowering plants that grow so widespread over the +world. It occurs in North America from the Atlantic to the Pacific coast, +in Europe, in Asia, and in the Arctic regions. This extensive range may in +part be accounted for by the fact that our plant belongs to the large and +aggressive family of the <i>Compositæ</i>, and is thus related to such invaders +as daisies, burdocks, and thistles. Still, the dandelion has more to +recommend it than mere family connection; for, despite its lowly aspect, +it is no poor relation, but, as we shall hope to show in the present +article, it has many virtues of its own which entitle it to respect.</p> + +<p>Prominent among these is its adaptability to the different conditions +under which it grows. It seems to make the best of everything. If by +chance a seed falls upon poor, thin soil, the young plant sends forth, as +rapidly as possible, a rosette of leaves pressed close to the earth. And +thus, on the principle that "possession is nine points of the law," it +secures for its roots the use of a certain amount of territory quite safe +from the encroachments of other plants. In rich ground the case is quite +different, for here there is so much nutriment in a small quantity of +earth, that the struggle for soil is not such a life and death matter as +in the less favored localities. Consequently we find a large number of +plants crowded together as close as they can stand; and it is obvious that +if, under these circumstances, the dandelion should develop a flat rosette +of leaves, the grass and other plants growing around would soon overshadow +it, and it would have small chance for life.</p> + +<p>Our plant, therefore, extends its leaves upward, and does its best to +elongate them so as to keep pace with the growth of its rivals. But as +these are for the most part grasses and plants which grow by elongation of +the stem, the race for sunshine is rather in favor of these other plants, +for the reason that a given amount of material put into a stem makes a +stiffer organ than when put into a leaf. Still, even with these odds +against it, the dandelion seems well able to hold its own, for it probably +derives more or less advantage from the recurved lobes, or teeth, which +give the plant its name. These are admirably fitted to act in much the +same manner as a ratchet; and when the neighboring grasses are blown +against the dandelion, a blade may slide along the margin of the leaf +toward the base; but, as it springs back from its own elasticity, it +cannot slide in the opposite direction, for a tooth will catch it, and +thus force it to help support the leaf, and hold it up to the sunshine. We +need not stop to consider how the dandelion behaves in soil which is +neither very rich nor very poor, for enough has been said to show that it +has not much to fear from any rivals it may meet under ordinary +circumstances.</p> + +<p>It is not only against the aggressions of neighboring plants, however, +that our dandelion needs to be prepared. +<!--039.png--><span class="pagenum"><a name="Page_10356" id="Page_10356">10356</a></span>It +is at least equally important +for its welfare that it have some means of protection against herbivorous +animals—not only such as might eat its leaves, but also the more stealthy +ones that live upon the food which plants store underground. All such foes +it thwarts by a means as simple as it is efficient. Every part of the +plant contains a milky juice which is intensely bitter, and a first taste +is quite enough to convince the most stupid animal that raw dandelion is +not good eating, and most animals know enough to let it severely alone. +Curiously enough, however, in this, as in many other cases, it happens +that what in nature acts to deter animals from eating the plant, with man +offers the chief attraction, for it is this very bitter principle +(<i>taraxacin</i>) which gives to dandelion greens their peculiar flavor, and +affords the essential element in the extract which physicians prescribe.</p> + +<p>The store of food, referred to above, which the dandelion accumulates in +its root, not infrequently enables it to pass, almost unharmed, through +dangers that with less provident plants would surely prove fatal. For +example, it must often happen that from drought or from being trampled +upon by animals, the leaves become wholly or in part destroyed. Now, if +there were no reserve store of food, the plant would have no chance of +rallying; but as it is, this food supplies the material for new growth, +and upon the return of favorable conditions, fresh leaves are developed, +and the plant lives on as before. Primarily, of course, the purpose of +this storage of food is to enable the plant to live on from year to year, +resting in the winter, and in the spring beginning work again with a good +start.</p> + +<p>In comparing the higher with the lower plants, the superiority of the +former is most beautifully shown in the better provision which is made for +the welfare of offspring; and in this regard our dandelion stands among +the highest. Before we can understand the ways in which our little plant +performs this part of its life work, we must briefly consider the +structure of the blossom.</p> + +<div class="figcenter" style="width: 500px;"> +<img src="images/i039-2.png" width="500" height="364" alt="Diagram of structure." title="" /> +<span class="caption"><span class="smcap">Fig. 2.</span></span> +</div> + +<p>If with a sharp knife we cut a blossom in halves, from the stem upward, +the parts represented in Fig. 2 will be disclosed. Surmounting the stalk +is a cushion-like receptacle, R, from the top of which arise a number of +tiny flowers, F, while from the side grow out a series of green scales, S, +forming an involucre around the whole. A single one of these florets, Fig. +3, exhibits the following parts: First, a bright yellow corolla, C O, +tubular below, but strap-shaped above, as if a tube had been split for +part of the way on one side, and the upper part flattened. Second, five +stamens, S K, attached by slender filaments, F M, to the tubular part of +the corolla, and with their anthers or pollen sacs, A N, joined together +by the edges to form a tube. Third, a single pistil having a long style, S +Y, which, above, passes through the anther tube, and bears at its end two +diverging stigmas, S G, and below connects by a short neck, N, with the +small ovary, O, which contains a solitary ovule. Fourth, a calyx, C X, +composed of numerous slender bristles.</p> + +<div class="figleft" style="width: 210px;"> +<img src="images/i039-3.png" width="210" height="412" alt="Drawing of structure." title="" /> +<span class="caption"><span class="smcap">Fig. 3.</span></span> +</div> + +<p>The purpose of these complex structures is, of course, in one way or +another to secure the development of the ovule into a seed fitted to +produce a new plant. This development will proceed only after the ovule +has been influenced (<i>i. e.</i>, fertilized) by pollen placed upon the +stigma; but when once the mysterious process of fertilization has taken +place, then there follows immediately those wonderful changes in the +blossom which culminate in the ripening of the fruit.</p> + +<p>There are but two possible ways in which fertilization may be secured; +either the pollen which affects the ovule must come from the same flower +(then called close fertilization), or the pollen must come from another +flower of the same kind (cross fertilization). Now, while either of these +methods will insure the production of a seed, numerous experiments go to +show that those offspring which result from cross fertilization are in +many ways superior to those which are produced from close fertilization; +and it is to the advantages of cross fertilization that we have to look +for an explanation of the significance of many peculiar structures, not +only of the dandelion, but of flowers in general.</p> + +<p>It is obvious that, to secure cross fertilization, there must be some +agent to transfer the pollen from one plant to another. Most commonly, +either the wind is taken advantage of for this purpose, as with elms, +pines, grasses, etc., or else flying insects are induced to perform the +office, as is the case with the majority of our familiar flowers. The wind +is a very wasteful carrier, +<!--040.png-->so that for every grain that is properly +placed, thousands, or even millions, may be lost. Insects, on the +contrary, waste but little; and, moreover, as Aristotle so shrewdly +observed, they habitually confine their visits, for a number of trips, +exclusively to the flowers of one species.</p> + +<p>The dandelion seems to fully appreciate the great advantages of securing +the services of insects, for it appeals most strongly to their love of +bright colors and their passion for sweets. As the flowers open, each tiny +golden cup is filled to the brim with purest nectar, and he must be a very +dull insect, indeed, that cannot see the brilliant head of flowers as far +as he can see anything. At any rate, it is not the dandelion's fault if he +does not, for the blossom is placed where it will be as conspicuous as +possible. If the surrounding herbage is tall, the flower stalk is +elongated, so that the crown of flowers may not be obscured. If the plants +around are low-lying, it would be wasteful to have a long stalk, so it has +a short one, sometimes so short that the blossom looks like a button in +the center of the leaf rosette. Economy of material is furthermore shown +in the fact that the stalk is always hollow, for it is a principle well +known to builders that, when there is required a pillar of a given +strength, less material is needed for the tubular form than for the solid +cylinder.</p> + +<div class="figleft" style="width: 54px;"> +<img src="images/i040-4.png" width="54" height="207" alt="Drawing of structure." title="" /> +<span class="caption"><span class="smcap">Fig. 4.</span></span> +</div> + +<div class="figright" style="width: 79px;"> +<img src="images/i040-5.png" width="79" height="310" alt="Drawing of structure." title="" /> +<span class="caption"><span class="smcap">Fig. 5.</span></span> +</div> + +<p>But to return to our flower. We have next to consider how the visits of +insects are utilized to secure cross fertilization. If we examine the +anther tube of a flower that has just opened, Fig. 4, we shall see that +the style has not yet protruded, but fills the entire cavity, except such +space as is occupied by a quantity of pollen which the anthers have shed. +So much of the style as is within the tube is thickly beset with hairs +that point upward; and when the lower portion elongates, this hairy part +brushes the pollen out of the tube, and protrudes, covered with the yellow +dust, Fig. 5. At this stage, an insect coming for nectar must rub against +the style, and so become more or less covered with pollen. None of it, +however, can get upon the stigmas, for they are not yet exposed. After a +short time has elapsed, during which much of the pollen has probably been +rubbed off, the style is seen to split at the top; and as the halves +separate and roll back, Fig. 3, their inner faces (the stigmas) are +exposed. If, now, the flower be visited by an insect which has previously +been to a younger flower, the pollen he brings will be deposited upon the +stigmas as he rubs against them, and cross fertilization will be effected.</p> + +<p>Let us suppose, however, that no insect visits the blossom—and this must +often happen to such as appear very early in the spring or late in the +fall, when hardly any insects are around. In such cases we find that seeds +are produced, and therefore we must infer that fertilization has in some +way or other been secured. An examination of a flower still older than any +we have considered, Fig. 6, will show us what takes place. Here it will be +seen that, after the stigmas have diverged, they continue to roll back, +until a coil of one or more turns has been made; and as a result of this +the stigmatic surface comes in contact with the hairs on the style, and +touches the pollen grains entangled by them. Still, the close +fertilization thus accomplished is only a last resort, and it can only +occur in the event of insects' visits having failed; for when pollen from +another flower has once fallen on the stigma, no pollen coming afterward +can have the least effect. Thus, we have another instance of the +dandelion's ability to make the best of its surroundings.</p> + +<div class="figleft" style="width: 118px;"> +<img src="images/i040-6.png" width="118" height="312" alt="Drawing of structure." title="" /> +<span class="caption"><span class="smcap">Fig. 6.</span></span> +</div> + +<p>It even adapts itself to the weather; for when the sun shines, the scales +of the involucre bend back, and the blossom is expanded to its fullest +extent; but in dull weather, or at night, the scales bend inward, and the +blossom is tightly closed. The advantages of this remarkable movement, +with its implied sensitiveness, is obvious when we consider that insects +are abroad only in sunshine, while at other times there is danger of dew +or rain getting into the nectar, and so spoiling it for the insects.</p> + +<p>After fertilization has been accomplished throughout the blossom, the +involucre closes, and remains closed during the ripening of the fruit. The +changes which now take place are as follows: In each flower the corolla, +stamens, and style, being of no further use, wither, and sever their +connection with the ovary; the ovule develops into a seed containing a +tiny plantlet well provided with food for its use during germination; +<!--041.png-->the +ovary grows to keep pace with the seed, its tissues become hardened, and a +number of spine-like projections develop near the upper part; and finally +the short neck which bears the calyx bristles elongates, pushing upward +the withered parts of the flower. At this stage the involucral scales bend +back through an arc of about 180°, the cushion-like receptacle becomes +almost spherically convex, the fruits radiate in all directions, the +bristles spread, and a beautiful cluster of little parachutes is presented +to the wind.</p> + +<div class="figleft" style="width: 207px;"> +<img src="images/i041-7.png" width="207" height="312" alt="Drawing of structure." title="" /> +<span class="caption"><span class="smcap">Fig. 7.</span></span> +</div> + +<div class="figright" style="width: 117px;"> +<img src="images/i041-8.png" width="117" height="335" alt="Drawing of structure." title="" /> +<span class="caption"><span class="smcap">Fig. 8.</span></span> +</div> + +<p>Even a glance at one of these fruits, Fig. 7, is sufficient to discover a +wonderful fitness for transportation by wind, and more careful study shows +that this fitness pervades every detail. For example, on examining the +bristles microscopically, Fig. 8, it is shown that they are not simple +threads, but each is hollow and has numerous projections extending on +either side, all of which serves to increase the buoyancy in a very +effective way.</p> + +<p>The experience of aeronauts has shown that a highly important part in the +equipment of a balloon, after the attainment of buoyancy, is the provision +of some means of arresting the balloon's progress when the destination has +been reached. One of the most successful means which they employ is the +grappling hook; and as we find the base of our diminutive parachute +provided with a number of upwardly directed spines, it seems fair to +conclude that these serve to arrest the fruit upon favorable soil. If it +comes to rest upon a smooth surface—which, of course, would be +barren—the next breeze would easily blow it away; but if it chance to +fall on soil or among other plants, the effect of the spines would be to +retain it against the power of even a strong wind. Thus, we may leave it +safely landed upon good soil, ready to begin under favorable conditions +the cycle of its wonderful life.—<i>Popular Science News.</i></p> + +<hr class="ChapterTopRule" /> + +<h2><a name="SYSTEMATIC_RELATIONS_OF_PLATYPSYLLUS_AS_DETERMINED_BY_THE_LARVA12" +id="SYSTEMATIC_RELATIONS_OF_PLATYPSYLLUS_AS_DETERMINED_BY_THE_LARVA12"></a>SYSTEMATIC RELATIONS OF PLATYPSYLLUS, AS DETERMINED BY THE LARVA.<a name="FNanchor_12_12" id="FNanchor_12_12"></a><a href="#Footnote_12_12" class="fnanchor">[12]</a></h2> + +<div class="c3">By <span class="smcap">Dr. C. V. Riley</span>.</div> + +<p>There is always a great deal of interest attaching to organisms which are +unique in character and which systematists find difficulty in placing in +any of their schemes of classification. A number of instances will occur +to every working naturalist, and I need only refer to Limulus, and the +extensive literature devoted, during the past decade, to the discussion of +its true position, as a marked and well-known illustration. In hexapods +the common earwig and flea are familiar illustrations. These osculant or +aberrant forms occur most among parasitic groups, as the Stylopidæ, +Hippoboscidæ, Pulicidæ, Mallophaga, etc. Probably no hexapod, however, has +more interested entomologists than <i>Platypsyllus castoris</i> Ritsema, a +parasite of the beaver. I cannot better illustrate the diversity of +opinion respecting its true position in zoology than by giving an epitome +of the more important literature upon it.</p> + +<div class="footnote"><p><a name="Footnote_12_12" id="Footnote_12_12"></a><a class="label" href="#FNanchor_12_12">[12]</a> Read at the meeting of the National Academy of Sciences, +April 20, 1888.</p></div> + +<p>J. Ritsema, in <i>Petites Nouvelles Entomologiques</i> for September 15, 1869, +described the species as <i>Platypsyllus castoris</i>. He found it on some +American beavers (<i>Castor canadensis</i>) in the zoological garden of +Rotterdam. He considered it to "undoubtedly" belong to the Suctoria of De +Geer, and to form a new genus of Pulicidæ.</p> + +<p>In the same year, in the <i>Tijdschrift voor Entomologie</i>, 2d ser., vol. v., +p. 185 (which I have not seen), the same author publishes what is +apparently a redescription of the insect. He gives his views more fully as +to its systematic position, considering that it belongs to the +Aphaniptera, and is equivalent to the Pulicidæ.</p> + +<p>In the same year, Prof. J. O. Westwood (having previously read a +description of the species, November 9, 1868, before the Ashmolean Society +of Oxford) published in the <i>Entomologist's Monthly Magazine</i>, vol. vi., +October, 1869, pp. 118-119, a full characterization of the insect under +the name of <i>Platypsyllus castorinus</i>. A new order, <i>Achreioptera</i>, is +established upon the species, which he very aptly likens, in general +appearance, to a cross between a flattened flea and a diminutive +cockroach. "The abnormal economy of the insect, its remarkable structure, +the apparent want of mandibles, our ignorance of its transformations, and +the possibility that the creature may be homomorphous in the larva and +pupa states," are the reasons assigned for establishing the new order, and +here Prof. Westwood is perfectly consistent, as in his famous +"Introduction to the Classification of Insects" the Forficulidæ are placed +in the order Euplexoptera; the Thripidæ in the order Thysanoptera; the +Phryganeidæ in the order Thrichoptera; the Stylopidæ in the order +Strepsiptera; and the Pulicidæ in the order Aphaniptera.</p> + +<p>In 1872, Dr. J. L. Le Conte published his paper "On <i>Platypsyllidæ</i>, a New +Family of Coleoptera" (Proc. Zool. Soc. of London for 1872, pp. 779-804, +pl. lxviii.), in which he shows that <i>Platypsylla</i> is undoubtedly +coleopterous and cannot possibly be referred to the Aphaniptera. Careful +descriptions and figures of anatomical details are given, and he finds +that its affinities are very composite, but in the direction of the +Adephagous and Clavicorn series. Its most convenient place is +<!--042.png--><span class="pagenum"><a name="Page_10357" id="Page_10357">10357</a></span>shown +to be +between the <i>Hydrophilidæ</i> and <i>Leptinidæ</i>. There seems to be no good +reason why the name <i>Platypsyllus</i> is here changed to <i>Platypsylla</i>, a +spelling adopted by most subsequent American writers.</p> + +<p>In 1874, Prof. Westwood, in the "<i>Thesaurus Entomologicus Oxoniensis</i>" +(Oxford, 1874), p. 194, pl. xxxvii., gives figures with details; reprints +his previous diagnosis, and maintains his previous course in erecting a +new order for the insect, without giving any additional reasons.</p> + +<p>In 1880, P. Megnin, in "Les Parasites et les maladies parasitaires," etc., +Paris, 1880, gives (pp. 66-67) a description of the family +"Platypsyllines" without expressing an opinion concerning the systematic +position. He also describes and figures the species.</p> + +<p>In 1882, Dr. Geo. H. Horn (Trans. Amer. Ent. Soc., x., 1882-83; Monthly +Proc., Feb. 10, 1882, p. ii.) exhibited drawings illustrating the anatomy +of <i>Platypsylla</i> and <i>Leptinus</i>, and showed that a close relationship +exists between these genera. Later, in his "Notes on Some Little Known +Genera and Species of Coleoptera" (Trans. Amer. Ent. Soc., x., 1882-83, +pp. 113-126, pl. v., 114-116), he reviews the characters, and explains and +illustrates the anatomical details. The differences he points out between +his observations and those of Le Conte are more particularly in the +mandibles. In connection with this paper he also describes and illustrates +the structure of Leptinillus, which he separates from Leptinus, and +demonstrates their close relationship with Platypsyllus.</p> + +<p>In 1883, Le Conte and Horn, in their "Classification of the Coleoptera of +North America" (Washington, Smithsonian Institution, 1883), give (pp. +13-15) a full description of the family characters, a little modified from +Le Conte's first description, but sustaining his views on the systematic +position of <i>Platypsyllidæ</i>.</p> + +<p>In 1883, Alphonse Bonhoure (Ann. Soc. de France, 1883; Bull, des Seances, +p. cxxvi.) exhibited drawings and specimens of <i>Platypsyllus castoris</i> +found in the <i>Departement des Bouches du Rhone</i>.</p> + +<p>In 1884, Edm. Reitter, in "<i>Platypsylla castoris</i> Rits. als Vertreter +einer neuer europaischen Coleopteren-Familie" (Wiener entom. Zeit. iii., +1884, pp. 19-21) gives a lengthy description of the species with special +regard to the sexual differences. He shows that the European insect is not +specifically distinct from the American form, but he does not express an +opinion on the position of the family among the Coleoptera.</p> + +<p>In the same year, Bonhoure (Ann. Soc. Ent. de France, 1884, pp. 143-153) +more fully records its discovery on <i>Castor fiber</i> taken in the +Petit-Rhone. It is a question whether this European beaver, now quite +rare, is distinct from ours. He gives a very good review of the subject, +with a plate of the most important details, after Horn, and he fully +indorses the coleopterological position of the insect.</p> + +<p>In the same year Ritsema (<i>Tijdschrift voor Entomologie</i>, 1883-84, +lxxxvi.) refers to Bonhoure's discovery of <i>Platypsylla</i> in France, and +corrects Reitter in some unimportant details.</p> + +<p>In 1885, Reitter, in "<i>Coleopterologische Notizen</i>" xiii. (Wiener +entomolog. Zeit., vol. iv., 1885, p. 274), answers Ritsema's criticism.</p> + +<p>In the same year, Dr. Friederich Brauer, in his masterly +"Systematisch-zoologische Studien" (Sitzh. der Kais. Akad. der Wissensch., +xci., p. 364), speaks of the relationship in the thoracic characters +between Mallophaga and Coleoptera as illustrated by Platypsyllus, by +inference admitting the coleopterous nature of the latter, but recognizing +that it has mallophagous affinities.</p> + +<p>In 1886, H. J. Kolbe, in his "Ueber die Stellung von Platypsyllus im +System" (Berlin entom. Zeitsch., xxx., 1886, pp. 103-105), discusses the +subject, without any new evidence, however. He concludes that most of its +characteristics relate it to the Corrodentia, and particularly to the +sub-order Mallophaga, in which it has its closest kinship in Liotheidæ. +The remarkable tripartite mentum he thinks should not be compared with the +bipartite mentum of Leptinus, and calls attention to the fact that in +Ancistrona in Mallophaga it is also trilobed.</p> + +<p>The above are the more important papers on the subject, though the insect +has been referred by other authors to both Neuroptera and Orthoptera.</p> + +<h3>CHARACTERS OF PLATYPSYLLUS.</h3> + +<div class="figleft" style="width: 150px;"> +<img src="images/i042.png" width="150" height="351" alt="LARVA." title="" /> +<span class="caption">LARVA OF PLATYPSYLLUS CASTORIS—DORSAL VIEW.</span> +</div> + +<div class="figright" style="width: 317px;"> +<img src="images/i043-1.png" width="317" height="421" alt="Platypsyllus Castoris." title="" /> +<span class="caption">PLATYPSYLLUS CASTORIS.</span> +</div> + +<p>Where the characters of the image have been so often described, it is +unnecessary to refer to them in detail, and I will only call attention to +the more striking structural features and to some omissions by, or +differences between, previous authors. A glance at the illustrations which +I have prepared will show the prevailing characteristics of this +interesting creature, its general +<!--043.png-->ovoid and flattened form, and more +particularly the flattened semicircular head. Dorsally, we notice the +rather prominent occiput fringed behind with short and broad depressed +spines or teeth which form a sort of comb, the prothorax trapezoidal and +but very slightly curved, with side margins strongly grooved. There is a +very distinct scutellem, and the two elytra are rounded at the tip and +without venation. Hind wings and eyes are both wanting. The abdomen shows +five segments, each with a row of depressed bristles.</p> + +<p>On the ventral surface we find among the more curious characteristics, +first the antennæ; these were originally described by Westwood as +three-jointed, the club being annulated. Le Conte could not distinctly +make out the number of annular joints upon this club, though he thought he +detected seven, which made nine joints to the whole antenna. The club is +received in the deep cup-shaped excavation of the second joint. Horn +thought he detected a division of the second joint, and resolved but six +segments in the club, making also nine joints to the whole antenna, but in +a somewhat different fashion from Le Conte. Westwood's figure shows eight +annuli to the club. He failed to find any trace of the mandibles, but Le +Conte described them as small, flat, subquadrate, with the inner side +deeply crenulate, and resembling those of <i>Corylophus</i>; the stipes well +developed, and biarticulate. Horn could not entirely make out the +mandibles as described by Le Conte, and rather concluded that what Le +Conte described is really one of the granules which occur behind the +labrum. He considered that the piece could hardly be even an aborted +mandible, because of its diminutive size.</p> + +<div class="figright" style="width: 150px;"> +<img src="images/i043-2.png" width="150" height="376" alt="Young Larva." title="" /> +<span class="caption">YOUNG LARVA.</span> +</div> + +<p>What all authors have agreed in calling the mentum is very noticeable, +being large and broad, and trilobed behind. The maxillæ are strong, with +complicated stipes and with two flat, thin lobes, the inner one smaller +than the outer and rounded at the tip, both lobes being ciliate. The +maxillary palpi are four-jointed, the labial palpi three-jointed. The +prosternum is very large, subtriangular, concealing the insertion of the +coxæ, and extending over the front part of the mesosternum, as does this +over the front of the metasternum. Six ventral segments of the abdomen are +visible behind the posterior coxæ, which conceal two and the base of a +third. The coxæ are flat and not at all prominent. The legs are +characterized by broad and flattened tibiæ and femora, and the strong +spines with which they are armed. The tarsi are five-jointed, the front +and middle pair with a row of claviform membraneous appendages each side, +which Le Conte found only in the male.</p> + +<p>American entomologists have been satisfied to follow Le Conte and Horn as +to the position of Platypsyllus. Yet with such diversity of opinion on the +subject among high European authorities, the importance of a knowledge of +the adolescent states has been recognized, as the character of either the +larva or pupa would settle the question.</p> + +<p>During a stay at West Point, Neb., in October, 1886, I learned from one of +my agents, Mr. Lawrence Bruner, that there was a beaver in a creek not far +from that point, and I at once made arrangements for him to trap the +beaver, and to look particularly for living specimens of Platypsyllus on +the skin, and especially the earlier stages. He succeeded in capturing the +beaver and sent me some fifteen specimens of the larva and also some +imagos, but neither eggs nor pupæ were found. A glance at the larva +satisfied me at once of its coleopterous nature; but as we have, waiting +to be +<!--044.png-->worked up and published, an <i>embarras de richesses entomologiques</i> +in the collections of the National Museum, and as circumstances largely +decide the precedence, I should probably not have called attention to this +larva for some time, had it not been that at the last monthly meeting of +the Entomological Society of Washington, Dr. Horn, who was present, +announced the finding, the present spring, by one of his correspondents, +of this very larva, and exhibited a specimen. Some points about it, and +especially the position of the spiracles, being yet rather obscure in his +mind, he requested me to examine my material, which I have thus been led +to do. I have made a figure of this larva which will sufficiently indicate +its nature.</p> + +<p>The general form of the trophi, and particularly the anal cerci, fully +settle the disputed point, and remove this insect completely from the +Mallophaga (none of which possess them), and confirm its position in the +Clavicorn series of the Coleoptera. Yet in the larva, as in the imago, the +effects of its parasitic life are shown in certain modifications which +approach the running section of the Mallophaga. Without going into details +I may say that, besides its general and more decided coleopterological +features, this larva is distinguished by the shortness and stoutness of +its legs, by the size and stoutness of the antennæ, by the stiff and long +depressed hairs on the dorsal and more particularly on the ventral +surface, and by the dorsal position of the abdominal spiracles, all +characters approaching the Mallophaga. The first pair of spiracles is +lateral, and may be said to be mesothoracic, being placed on the +mesothoracic joint, but on a distinct fold. The eight abdominal spiracles +are placed on the sides of the dorsum, and in this respect recall the +parasitic triungulin of the meloid larvæ. The mandibles are barely +corneous, and they are more elongate and curved in the younger than in the +older larva, while the legs are also relatively stouter, more curved, and +with a much longer and sharper claw in the younger larva, which seems well +fitted for grasping the hairs of its host.</p> + +<p>There can no longer be any doubt, therefore, about the true position of +Platypsyllus. The eggs will probably be found attached in some way to the +hairs of the animal they are laid on, much as they are in Mallophaga, and +the pupa is probably formed in the nests of the host, and not upon the +skin, which will explain the reason for its not occurring with the larva +and imago upon the beaver, either in the case of my specimens or those of +Dr. Horn.</p> + +<p>The greatest resemblance of Platypsyllus in the imago state to the +Mallophaga is found in the spinous comb on the hind border of the occiput, +the arrangement of the spines on the abdomen, and the superficial antennal +structure, but particularly in the broad trilobed mentum. All of the other +characteristics are readily referable to the Coleoptera, though, as Le +Conte pointed out, they are composite, recalling in the antennæ the +Grynidæ, in the pronotum the Silphidæ, in the mesosternum Limulodes, in +the elytra the Staphilindæ, in the legs the Anisotomidæ, and in the +mandibles the Corylophidæ. The scutellum and the five-jointed tarsi at +once remove it from Mallophaga, and it is a wonder that Le Conte and Horn +have not more fully insisted on this fact. The trophi are very +complicated, and there are various details of structure not noticed or not +mentioned by any of the writers upon the subject hitherto.</p> + +<p>I have been led to very carefully examine the imago, and the more closely +I have done so, the more completely I realize the accuracy of Le Conte's +original work. The mandibles are visible or not, according as they are +exposed or withdrawn, and their existence may depend on the sex, as, so +far as my material justifies conclusion, they are visible in the male +only. Where found they correspond to Le Conte's description. Even in the +larva they are weak and of doubtful service in mastication, while in the +imago they are, as is also the labrum, quite rudimentary, which fact +hardly justifies us, however, in arguing their non-existence.</p> + +<p>As confirmatory of the affinities of Platypsyllus, as here proved, it may +be mentioned that <i>Leptinus testaceous</i> Mull., the only species of its +genus, is known to be parasitic on mice, as it has been found upon them in +Philadelphia by Dr. Jno. A. Ryder, and I have taken it in the nests of a +common field mouse near Washington. But still more interesting is the fact +that <i>Leptinillus validus</i> Horn (also the only species of its genus) is an +associate parasite of Platypsyllus on the beaver, a number of both having +been taken by one of my agents, Mr. A. Koebele, in San Francisco, from +beaver skins brought from Alaska.</p> + +<div class="figright" style="width: 199px;"> +<img src="images/i044-1.png" width="199" height="475" alt="Larva of Platypsyllus Castoris." title="" /> +<span class="caption">LARVA OF PLATYPSYLLUS CASTORIS.</span> +</div> + +<p>In reference to the classificatory value that should be attached to an +aberrant type like this, I have already expressed my opinion in a paper on +Megathymus, a Lepidopteron that connects in many ways the two great +divisions of butterflies and moths, published in the Transactions of the +Academy of Sciences of St. +<!--045.png--> +<span class="pagenum"><a name="Page_10358" id="Page_10358">10358</a></span> +Louis, volume iii., 1876, and will take the +liberty of reading a few passages therefrom:</p> + +<div class="blockquot"><p>"Between all classificatory divisions, from variety to kingdom, +the separating lines we draw get more and more broken in +proportion as our knowledge of forms, past and present, +increases. Every step in advance toward a true conception of the +relations of animals brings the different groups closer +together, until at last we perceive an almost continuous chain. +Even the older naturalists had an appreciation of this fact. +Linnæus' noted dictum, '<i>Natura saltus non facit</i>' implies it; +and Kirby and Spence justly observe that 'it appears to be the +opinion of most modern physiologists that the series of +affinities in nature is a concatenation or continuous series; +and that though an hiatus is here and there observable, this has +been caused either by the annihilation of some original group or +species, or that the objects required to fill it up are still in +existence but have not yet been discovered.'"</p> + +<p>"Modern naturalists find in this more or less gradual blending +their strongest arguments in favor of community of descent; and +speculation as to the origin, or outcome rather, in the near +present or remote past of existing forms is naturally and very +generally indulged, even by those who a few years back were more +inclined to ridicule than accept Darwinian doctrine. Shall we +then say that the old divisions must be discarded because not +absolute? As well might we argue for the abolition of the four +seasons because they differ with the latitude, or because they +gradually blend into each other. Entomologists will always speak +of moths and butterflies, howsoever arbitrary the groups may +come to be looked upon, or however numerous the intermediate +gradations."</p> + +<p>"Families should, I think, be made as comprehensive as possible, +and not unduly multiplied; and in considering aberrant forms, +the objects of classification are best subserved by retaining +them in whatever division can claim the balance of characters. +It is better to widen than to restrict in the higher groups. Le +Conte does better service in bringing Platypsylla among the +Coleoptera than does Westwood in creating a new +order—Achreioptera—for it. Phylloxera, in Homoptera, is much +more wisely retained in the Aphididæ than made the type of a new +family."</p></div> + +<p>Platypsyllus, therefore, is a good Coleopteron, and in all the characters +in which it so strongly approaches the Mallophaga it offers merely an +illustration of modification due to food habit and environment. In this +particular it is, however, of very great interest as one of the most +striking illustrations we have of variation in similar lines through the +influence of purely external or dynamical conditions, and where genetic +connection and heredity play no part whatever. It is at the same time +interesting because of its synthetic characteristics, being evidently an +ancient type from which we get a very good idea of the connection in the +past of some of the present well-defined orders of insects.</p> + +<p>Westwood, though now an octogenarian, may safely be called England's most +eminent entomologist by virtue of the character and volume of the work +which he has accomplished. Dr. Le Conte was, <i>facile princeps</i>, America's +leading coleopterist. I do not know that any greater tribute could be +added to the sound judgment and deep knowledge possessed by that late +distinguished member of the Academy than the confirmation of his views as +opposed to the views of Westwood and other European authorities which the +discovery of this larva now gives us.</p> + +<hr class="ChapterTopRule" /> + +<h2><a name="THE_SPECTRA_OF_OXYGEN" id="THE_SPECTRA_OF_OXYGEN"></a>THE SPECTRA OF OXYGEN.</h2> + +<p>The author has observed a fact which furnishes a remarkable demonstration +of the law of the production of the dark bands which he has detected in +the spectrum of oxygen. The phenomena of elective absorption in oxygen gas +are manifested in two mutually distinct spectral systems. A first system, +formed of fine rays, follows the law of the product of the gaseous system +traversed by its density. The second system is formed of bands much less +easily resolved, is governed by the law of the product of the thickness by +the square of the density. This second law being quite novel in spectral +analysis, the author has instituted experiments necessary to prove that +this system of obscure bands really belongs to oxygen. These experiments +range from pressures of 100 atmospheres down to those of a few units, and +with lengths of tubes from 0.42 meter to 60 meters. At the same time +prolonged observations have been made upon the atmosphere, brought into +connection with the experiments in the tubes. These observations, and +especially those made during autumn last on the Pic du Midi, prove that +all the bands of the spectrum of oxygen are found in the spectrum of the +solar light if it is allowed to traverse a sufficient thickness of the +atmospheric medium. Further, on comparing, by the aid of photography, the +intensities of the bands of the atmospheric spectrum with those given in +the tubes, the author has found that the intensities of these atmospheric +bands fulfill the law of the square. It appears from <i>Wiedemann's Annalen</i> +that M. Olszewski, when liquefying oxygen, examined its spectrum and +ascertained the existence of the bands in question with a stratum of 7 mm. +of liquid oxygen.—<i>J. Jansen.</i></p> + +<hr class="ChapterTopRule" /> + +<h2><a name="ON_A_THEORY_CONCERNING_THE_SUDDEN_LOSS_OF_MAGNETIC_PROPERTIES_OF_IRON_AND" +id="ON_A_THEORY_CONCERNING_THE_SUDDEN_LOSS_OF_MAGNETIC_PROPERTIES_OF_IRON_AND"></a>ON +A THEORY CONCERNING THE SUDDEN LOSS OF MAGNETIC PROPERTIES OF IRON AND +NICKEL.</h2> + +<div class="c3">By Mr. <span class="smcap">H. Tomlinson</span>, B.A.</div> + +<p>Experiments by himself and other observers have shown that the +temperatures at which iron and nickel lose their magnetic properties +depend on the specimens used and the magnetizing forces employed; but the +temperatures at which they <i>begin to lose</i> these properties are +definite—for nickel about 300° C., and iron about 680° C. The author's +own experiments on "Recalescence of Iron" show two critical temperatures; +and Pinchon has shown by calorimetric measurement that between 660° and +720° C., and between 1,000° and 1,050° C., heat becomes latent. All these +facts seem to indicate a molecular rearrangement about these temperatures.</p> + +<p>In his proposed theory he assumes that the molecules +<!--046.png-->of iron (say) +contain magnetic atoms capable of motions of translation and of rotation. +These tend to form closed magnetic circuits, but at ordinary temperatures +are unable to do so on account of the close proximity of their centers. On +raising the temperature their centers are further separated, till at about +680° C. their polar extremities rush together, forming complete circuits +and exhibiting no external magnetic properties. On cooling down, the +centers approach until the gravitation attraction overcomes the magnetic +attraction of their poles, when the magnetic properties reappear.</p> + +<p>Prof. Ayrton asked whether the author had made experiments on the +reappearance of magnetic properties when raised to a white heat, and Prof. +Thompson inquired whether cobalt had been tested. Both questions were +answered negatively.</p> + +<hr class="ChapterTopRule" /> + +<h2><a name="POISON_OF_THE_SOMALIS_EXTRACTED_FROM_THE_WOOD_OF_THE_OUABAIO" id="POISON_OF_THE_SOMALIS_EXTRACTED_FROM_THE_WOOD_OF_THE_OUABAIO"></a>POISON OF THE SOMALIS, EXTRACTED FROM THE WOOD OF THE OUABAIO.</h2> + +<p>The principle in question, ouabaine, forms rectangular plates, very +slender, of a nacreous appearance. It is absolutely white, inodorous, and +not appreciably bitter. It contains no nitrogen, and does not react with +coloring matters. At a boiling heat, in presence of dilute acids, it is +split up, yielding a reductive sugar. Its composition is +C<sub>90</sub>H<sub>45</sub>O<sub>12</sub>. It is poisonous if introduced into the circulation, +but not if swallowed.—<i>M. Arnaud, in Comptes Rendus.</i></p> + +<hr class="ChapterTopRule" /> +<h2 style="padding-bottom: 1em;"><a name="ADVERTISEMENTS" +id="ADVERTISEMENTS"></a>(Advertisements.)</h2> + +<div class="c3">A New Catalogue of Valuable Papers</div> + +<div style="text-align: justify;">Contained in <span class="smcap">Scientific American Supplement</span> during the past ten years, +sent <i>free of charge</i> to any address. MUNN & CO., 361 Broadway, New York.</div> + +<hr style="width: 45%;" /> + +<div class="c3">THE SCIENTIFIC AMERICAN</div> + +<div class="c2">Architects and Builders Edition.</div> + +<div class="c3">$2.50 a Year. Single Copies, 25 cts.</div> + +<p>This is a Special Edition of the <span class="smcap">Scientific American</span>, issued monthly—on +the first day of the month. 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Patents are obtained +on the best terms.</p> + +<p>A special notice is made in the <b>Scientific American</b> of all inventions +patented through this Agency, with the name and residence of the Patentee. +By the immense circulation thus given, public attention is directed to the +merits of the new patent, and sales or introduction often easily effected.</p> + +<p>Any person who has made a new discovery or invention can ascertain, free +of charge, whether a patent can probably be obtained, by writing to <span class="smcap">Munn & +Co.</span></p> + +<p>We also send free our Hand Book about the Patent Laws, Patents, Caveats, +Trade Marks, their costs, and how procured. Address</p> + +<div style="text-align: center; font-weight: bold;"> +<span style="font-size: large;">MUNN & CO.,</span><br /> +<span style="padding-left: 5em;">361 Broadway, New York.</span><br /> +Branch Office, 622 and 624 F St., Washington, D. C. +</div> + +<hr class="ChapterTopRule" /> + +<div class="c3"><a name="Changes" id="Changes"></a>Transcriber's Amendments</div> + +<p>Transcriber's Note: Some illustrations may have been moved. We have +rendered consistent on a per-word-pair basis the hyphenation or spacing of +such pairs when repeated in the same grammatical context. The table of +contents has been moved to the front.</p> + +<p>Other changes are listed below. The listed source publication page number +also applies in this reproduction except for the table of contents since +it has been moved.</p> + +<pre> + Page Change + +10343 [Fig. 1 redrawn slightly to reduce the reader's confusion.] +10345 [<span class="smcap">Nature.</span>][Heading deleted.] +10345 12,600 lb. per square inch [(psi)].[also in following lines.] +10346 [First line of heading moved to footnote.] +10347 as much as [a] plank of the same size +10347 For these upper floors hard-wood[hardwood] plank, +10349 asserted pretty generally thoughout[throughout] the country +10349 employes[employees] will no longer be known as "gas house +10350 reappear in the little glow lamp[glow-lamp][multiple instances] +10351 through[though] I doubt whether it is visible +10351 due to the vacum[vacuum], +10351 and to the atonishment[astonishment] of my fellow +10352 the many disagreeable symptons[symptoms], +10352 [Part of Care of The Eyes header moved to footnote.] +10354 but on miscroscopical[microscopical] examination +10354 neigborhood[neighborhood] in which we live. +10355 It[Its] parallax, as determined by Sir R. S. Ball, +10355 The well known[well-known] double star 61 Cygni +10356 [Fig. 3: Illegible text re-composed.] +10358 [Advertisements header added.] +10358 [Table of contents moved to front of publication.] +10358 The One Hundred and Twenty Foot[Ton] Shears {Table of Contents} +</pre> + +<div style="padding-top: 1em;"><a href="#Start">Start of text.</a></div> + +<hr class="ChapterTopRule" /> + + + + + + + + +<pre> + + + + + +End of the Project Gutenberg EBook of Scientific American Supplement, No. +648, June 2, 1888., by Various + +*** END OF THIS PROJECT GUTENBERG EBOOK SC. 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