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+The Project Gutenberg EBook of Scientific American Supplement, No. 303,
+by Various
+#2 in our series
+
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+
+Title: Scientific American Supplement, No. 303
+       October 22, 1881
+
+Author: Various
+
+Release Date: June, 2005 [EBook #8296]
+[Yes, we are more than one year ahead of schedule]
+[This file was first posted on July 4, 2003]
+
+Edition: 10
+
+Language: English
+
+Character set encoding: ASCII
+
+*** START OF THE PROJECT GUTENBERG EBOOK SCIENTIFIC AMERICAN NO. 303 ***
+
+
+
+
+Olaf Voss, Don Kretz, Juliet Sutherland, Charles Franks
+and the Online Distributed Proofreading Team.
+
+
+
+
+[Illustration]
+
+
+
+
+SCIENTIFIC AMERICAN SUPPLEMENT NO. 303
+
+
+
+
+NEW YORK, OCTOBER 22, 1881
+
+Scientific American Supplement. Vol. XII, No. 303.
+
+Scientific American established 1845
+
+Scientific American Supplement, $5 a year.
+
+Scientific American and Supplement, $7 a year.
+
+
+       *       *       *       *       *
+
+     TABLE OF CONTENTS
+
+I.   ENGINEERING AND MECHANICS.--New Eighty-ton Steam Hammer at the Saint
+     Chamond Works, France.--7 figures.--Elevation of hammer.--Profile--
+     Transverse section.--Profile view of foundation, etc.--Plan of
+     plant.--General plan of the forging mill.--Details of truss and
+     support for the cranes.
+
+     Great Steamers.--Comparative details of the Servia, the City of Rome,
+     the Alaska, and the Great Eastern.
+
+     Improved Road Locomotive.--2 figures.--Side and end views
+
+     American Milling Methods. By ALBERT HOPPIN.--Ten years' progress.--Low
+     milling.--Half high milling.--High milling.--Important paper read
+     before the Pennsylvania State Millers' Association.
+
+     Machine for Dotting Tulles and other Light Fabrics.--3 figures.
+
+II.  TECHNOLOGY AND CHEMISTRY.--The Reproduction and Multiplication of
+     Negatives. By ERNEST EDWARDS.
+
+     A New Method of Making Gelatine Emulsion. By W. K. BURTON.
+
+     The Pottery and Porcelain Industries of Japan.
+
+     Crystallization Table.
+
+     The Principles of Hop Analysis. By Dr. G. O. CECH.
+
+     Water Gas.--A description of apparatus for producing cheap gas, and
+     some notes on the economical effects of using such gas with gas
+     motors, etc.--By J. EMERSON DOWSON.
+
+     On the Fluid Density of Certain Metals. By Professors CHANDLER ROBERTS
+     and T. WRIGLESON.
+
+III. PHYSICS, ELECTRICITY, ETC.--Electric Power.--The nature and uses of
+     electricity.--Electricity vs. steam.
+
+     On the Method of Obtaining and Measuring Very High Vacua with a
+     Modified Form of Sprengel Pump. By Prof OGDEN N. ROOD.--4 figures.--
+     Apparatus for obtaining vacua of one four hundred-millionth of an
+     atmosphere--Construction.--Manipulation.--Calculations.--Results
+
+IV.  ART, ARCHITECTURE, ETC.--Old Wrought Iron Gates, Guildhall.
+     Worcester, England. 1 figure.
+
+     The French Crystal Palace, Park of St. Cloud, Paris. 1 full page
+     illustration.
+
+     Suggestions in Architecture. A Castellated Chateau. Perspective and
+     plan. Chateau in the AEgean Sea.
+
+V.   HYGIENE AND MEDICINE.--Hydrophobia Prevented by Vaccination.
+
+     On Diptera as Spreaders of Disease. By J. W. SLATER.
+
+     On the Relations of Minute Organisms to Certain Specific Diseases.
+
+VI.  ASTRONOMY--The Centenary of the Discovery of Uranus. By F. W. DENNING.
+     2 figures. Approximate place of Uranus among the stars at its
+     discovery, March l3, 1871.--Orbits of the Uranian Satellites.
+
+VII. BIOLOGY, ETC.--The Varying Susceptibility of Plants and Animals to
+     Poisons and Disease.
+
+     Kind Treatment of Horses.
+
+       *       *       *       *       *
+
+
+
+
+NEW EIGHTY TON STEAM HAMMER AT THE SAINT CHAMOND WORKS
+
+
+Ever since the improvements that have been introduced into the
+manufacture of steel, and especially into the erection of works for its
+production, have made it possible to obtain this metal in very large
+masses, it has necessarily been preferred to iron for all pieces of
+large dimensions, inasmuch as it possesses in the highest degree that
+homogeneousness and resistance which are so difficult to obtain in the
+latter metal. It has consequently been found necessary to construct
+engines sufficiently powerful to effect the forging of enormous
+ingots, as well as special furnaces for heating them and apparatus for
+manipulating and transporting them.
+
+The greatest efforts in this direction have been made with a view to
+supplying the wants of heavy artillery and of naval constructions;
+and to these efforts is metallurgy indebted for the creation of
+establishments on a scale that no one would have dared a few years ago
+to think of. The forging mill which we are about to describe is one of
+those creations which is destined to remain for a long time yet very
+rare; and one which is fully able to respond, not only to all present
+exigencies, but also, as far as can be foreseen, to all those that may
+arise for a long period to come. The mill is constructed as a portion of
+the vast works that the Compagnie des Forges et Acieries de la Marine
+own at Saint Chamond, and which embrace likewise a powerful steel works
+that furnishes, especially, large ingots exceeding 100 tons in weight.
+
+The mill consists, altogether, of three hammers, located in the same
+room, and being of unequal powers in order to respond to different
+requirements. The largest of these hammers is of 80 tons weight, and
+the other two weigh respectively 35 and 28 tons. Each of them has
+a corresponding furnace for heating by gas, as well as cranes for
+maneuvering the ingots and the different engines. The general plan view
+in Fig. 4 shows the arrangement of the hammers, cranes, and furnaces in
+the millhouse.
+
+[Illustration: FIG. A.--ELEVATION OF A HAMMER. FIG. B.--PROFILE VIEW]
+
+The gas generators which supply the gas-furnaces are located out of
+doors, as are the steam-generators. The ingots are brought from the
+steel factory, and the forged pieces are taken away, by special trucks
+running on a system of rails. We shall now give the most important
+details in regard to the different parts of the works.
+
+_The Mill-House_--This consists of a central room, 262 feet long, 98
+feet wide, and 68 feet in height, with two lean-to annexes of 16 feet
+each, making the total width 100 feet. The structure is wholly of metal,
+and is so arranged as to permit of advantage being taken of every foot
+of space under cover. For this purpose the system of construction
+without tie-beams, known as the "De Dion type," has been adopted. Fig.
+1 gives a general view of one of the trusses, and Fig. 5 shows some
+further details. The binding-rafters consist of four angle-irons
+connected by cross-bars of flat iron. The covering of corrugated
+galvanized iron rests directly upon the binding-rafters, the upper parts
+of which are covered with wood for the attachment of the corrugated
+metal. The spacing of these rafters is calculated according to the
+length of the sheets of corrugated iron, thus dispensing with the use of
+ordinary rafters, and making a roof which is at once very light and very
+durable, and consequently very economical. Rain falling on the roof
+flows into leaden gutters, from whence it is carried by leaders into a
+subterranean drain. The vertical walls of the structure are likewise of
+corrugated iron, and the general aspect of the building is very original
+and very satisfactory.
+
+_The 80 Ton Hammer_--The three hammers, notwithstanding their difference
+in power, present similar arrangements, and scarcely vary except in
+dimensions. We shall confine ourselves here to a description of the 80
+ton apparatus. This consists, in addition to the hammer, properly so
+called, of three cranes of 120 tons each, serving to maneuver the pieces
+to be forged, and of a fourth of 75 tons for maneuvering the working
+implements. These four cranes are arranged symmetrically around the
+hammer, and are supported at their upper extremity by metallic stays.
+Besides the foregoing there are three gas furnaces for heating the
+ingots. Figs. 1, 2, and 3 show the general arrangement of the apparatus.
+
+_Foundations of the Hammer and Composition of the Anvil-Bed_--To obtain
+a foundation for the hammer an excavation was made to a depth of 26 feet
+until a bed of solid rock was reached, and upon this there was then
+spread a thick layer of beton, and upon this again there was placed a
+bed of dressed stones in the part that was to receive the anvil-stock
+and hammer.
+
+On this base of dressed stones there was placed a bed formed of logs
+of heartwood of oak squaring 16 inches by 3 feet in height, standing
+upright, joined together very perfectly, and kept in close juxtaposition
+by a double band of iron straps joined by bolts. The object of this
+wooden bed was to deaden, in a great measure, the effect of the shock
+transmitted by the anvil-stock.
+
+NEW EIGHTY-TON STEAM HAMMER AT THE ST CHAMOND WORKS.
+
+[Illustration: FIG. 1.--TRANSVERSE SECTION.]
+
+[Illustration: FIG. 2.--PLAN.]
+
+[Illustration: FIG. 3.--PROFILE VIEW.]
+
+[Illustration: FIG. 4.--GENERAL PLAN OF THE FORGING MILL.]
+
+[Illustration: FIG. 5.--DETAILS OF THE TRUSSAND SUPPORT FOR THE CRANE.]
+
+_The Anvil-Stock_.--The anvil-stock, which is pyramidal in shape, and
+the total weight of which amounts to 500 tons, is composed of superposed
+courses, each formed of one or two blocks of cast iron. Each course
+and every contact was very carefully planed in order to make sure of
+a perfect fitting of the parts; and all the different blocks were
+connected by means of mortises, by hot bandaging, and by joints with
+key-pieces, in such a way as to effect a perfect solidity of the parts
+and to make the whole compact and impossible to get out of shape.
+
+The anvil-stock was afterwards surrounded by a filling-in of masonry
+composed of rag-stones and a mortar made of cement and hydraulic lime.
+This masonry also forms the foundation for the standards of the hammer,
+and is capped with dressed stone to receive the bed-plates.
+
+_The Power-Hammer_ (Figs. A and B).--The power-hammer, properly
+so-called, consists, in addition to the hammer-head, of two standards to
+whose inner sides are bolted guides upon which slides the moving mass.
+The bed-plates of cast iron are 28 inches thick, and are independent of
+the anvil-stock. They are set into the bed of dressed stone capping the
+foundation, and are connected together by bars of iron and affixed to
+the masonry by foundation bolts. To these bedplates are affixed the
+standards by means of bolts and keys. The two standards are connected
+together by iron plates four inches in thickness, which are set into the
+metal and bolted to it so as to secure the utmost strength and solidity.
+The platform which connects the upper extremities of the standards
+supports the steam cylinder and the apparatus for distributing the
+steam. The latter consists of a throttle valve, twelve inches in
+diameter, and an eduction valve eighteen inches in diameter, the
+maneuvering of which is done by means of rods extending down to a
+platform upon which the engineman stands. This platform is so situated
+that all orders can be distinctly heard by the engineman, and so that
+he shall be protected from the heat radiated by the steel that is
+being forged. All the maneuvers of the hammers are effected with most
+wonderful facility and with the greatest precision.
+
+The piston is of cast-steel, and the rod is of iron, 12 inches in
+diameter. The waste steam is carried out of the mill by a pipe, and,
+before being allowed to escape into the atmosphere, is directed into an
+expansion pipe which it penetrates from bottom to top. Here a portion of
+the water condenses and flows off, and the steam then escapes into
+the open air with a greatly diminished pressure. The object of this
+arrangement is to diminish to a considerable extent the shocks and
+disagreeable noise that would be produced by the direct escape of the
+steam at quite a high pressure and also to avoid the fall of condensed
+water.
+
+The following are a few details regarding the construction of the
+hammer:
+
+  Total height of foundations........... 26    ft.
+  From the ground to the platform ...... 28     "
+
+  Platform .............................. 3.25  "
+  Height of cylinder.................... 21     "
+                                         ________
+
+      Total height...................... 78.25 ft.
+
+  Weight of anvil-stock................ 500 tons.
+  Weight of bed-plates................. 122  "
+  Weight of standards.................. 270  "
+  Weight of platform and cylinder...... 148  "
+  Piston, valves, engineman's platform,
+    hammer, etc........................ 160  "
+                                        __________
+
+      Total weight................... 1,200 tons.
+
+  Weight of the hammer.................. 80 tons.
+  Maximum fall.......................... 25.75 ft.
+  Distance apart of the standards....... 21.6   "
+  Width of hammer.......................  6     "
+  Pressure of steam..................... 16 lb.
+  Effective pressure to lift 80 tons....  7  "
+_Description of Figures_.--A, the 80-ton hammer; B, B1, B2, cranes; C,
+C1, C2, supports of cranes; D, D1, D2, gas furnaces; A1, the 35-ton
+hammer; A2, the 28-ton hammer; EE, railways; F, engineman's platform; G,
+lever for maneuvering the throttle valve; H, an ingot being forged.
+
+       *       *       *       *       *
+
+
+
+
+GREAT STEAMERS.
+
+
+The _Brooklyn Eagle_ gives a very interesting description of the three
+new steamships now almost completed and shortly to be placed in the New
+York and Liverpool trade by the Cunard, Inman, and Williams and Guion
+lines. The writer has prepared a table comparing the three vessels
+with each other and with the Great Eastern, the only ship of greater
+dimensions ever built. We give as much of the article as our space will
+allow, and regret that we have not the room to give it entire:
+
+     Line.         Cunard.       Inman.        Guion.    Admiralty.
+    Vessel.        Servia     City of Rome.    Alaska.    Great[1]
+
+  Length        530 feet.     546 feet.     520 feet.     679 feet.
+  Breadth        52 feet.      52 ft. 3 in.  50 ft. 6 in.  82 feet.
+  Depth          44 ft. 9 in.  37 feet.      38 feet.      60 feet.
+  Gross ton'ge     8,500         8,300         8,000      13,344[2]
+  Horse pow'r     10,500        10,000        11,000       2,600
+  Speed          171/2 knots.    18 knots.     18 knots.    14 knots.
+  Sal'n pas-                                 320 and 52
+    sengers.       450           300          2d class
+  Steerage         600         1,500         1,000
+  Where          Clydeb'nk     Barrow in      Clyde,
+    built.        Thomson       Furness       Elder
+  Date of
+    sailing.     October 22    October 13    November 5
+
+[Footnote 1: To be sold at auction soon.]
+
+[Footnote 2: Net register.]
+
+In 1870 the total tonnage of British steam shipping was 1,111,375; the
+returns for the year 1876 showed an increase to 2,150,302 tons, and from
+that time to the present it has been increasing still more rapidly. But,
+as can be seen from the above table, not only has the total tonnage
+increased to this enormous extent, but an immense advance has been made
+in increasing the size of vessels. The reason for this is, that it has
+been found that where speed is required, along with large cargo and
+passenger accommodation, a vessel of large dimensions is necessary, and
+will give what is required with the least proportionate first cost as
+well as working cost. Up to the present time the Inman line possessed,
+in the City of Berlin, of 5,491 tons, the vessel of largest tonnage in
+existence. Now, however, the Berlin is surpassed by the City of Rome by
+nearly 3,000 tons, and the latter is less, by 200 tons, than the Servia,
+of the Cunard line. It will be observed, too, that while there is not
+much difference between the three vessels in point of length, the depth
+of the Alaska and the City of Rome, respectively, is only 38 feet and 37
+feet, that of the Servia is nearly 45 feet as compared with that of the
+Great Eastern of 60 feet. This makes the Servia, proportionately, the
+deepest ship of all. All three vessels are built of steel. This metal
+was chosen not only because of its greater strength as against iron,
+but also because it is more ductile and the advantage of less weight is
+gained, as will be seen when it is mentioned that the Servia, if built
+of iron, would have weighed 620 tons more than she does of steel, and
+would have entailed the drawback of a corresponding increase in draught
+of water. As regards rig, the three vessels have each a different style.
+The Cunard Company have adhered to their special rig--three masts, bark
+rigged--believing it to be more ship shape than the practice of fitting
+up masts according to the length of the ship. On these masts there is a
+good spread of canvas to assist in propelling the ship. The City of Rome
+is rigged with four masts; and here the handsome full-ship rig of the
+Inman line has been adhered to, with the addition of the fore and aft
+rigged jigger mast, rendered necessary by the enormous length of the
+vessel. It will be seen that the distinctive type of the Inman line
+has not been departed from in respect to the old fashioned but still
+handsome profile, with clipper bow, figurehead, and bowsprit--which
+latter makes the Rome's length over all 600 feet. For the figurehead
+has been chosen a full length figure of one of the Roman Caesars, in the
+imperial purple. Altogether, the City of Rome is the most imposing and
+beautiful sight that can be seen on the water. The Alaska has also four
+masts, but only two crossed.
+
+The length of the City of Rome, as compared with breadth, insures long
+and easy lines for the high speed required; and the depth of hold being
+only 37 feet, as compared with the beam of 52 feet, insures great
+stability and the consequent comfort of the passengers. A point calling
+for special notice is the large number of separate compartments formed
+by water tight bulkheads, each extending to the main deck. The largest
+of these compartments is only about 60 feet long; and, supposing that
+from collision or some other cause, one of these was filled with water,
+the trim of the vessel would not be materially affected. With a view to
+giving still further safety in the event of collision or stranding, the
+boilers are arranged in two boiler rooms, entirely separated from each
+other by means of a water tight iron bulkhead. This reduces what, in
+nearly all full-powered steamships, is a vast single compartment, into
+two of moderate size, 60 feet in length; and in the event of either
+boiler room being flooded, it still leaves the vessel with half her
+boiler power available, giving a speed of from thirteen to fourteen
+knots per hour. The vessel's decks are of iron, covered with teak
+planking; while the whole of the deck houses, with turtle decks and
+other erections on the upper deck, are of iron, to stand the strains
+of an Atlantic winter. Steam is supplied by eight cylindrical tubular
+boilers, fired from both ends, each of the boilers being 19 feet long
+and having 14 feet mean diameter. There are in all forty eight furnaces.
+The internal arrangements are of the finest description. There are two
+smoking rooms, and in the after deckhouse is a deck saloon for ladies,
+which is fitted up in the most elegant manner, and will prevent the
+necessity of going below in showery weather. At the sides of the
+hurricane deck are carried twelve life boats, one of which is fitted as
+a steam launch. The upper saloon or drawing-room is 100 feet long, the
+height between decks being 9 feet. The grand dining-saloon is 52 feet
+long, 52 feet wide, and 9 feet high, or 17 feet in the way of the large
+opening to the drawing-room above. This opening is surmounted by a
+skylight, and forms a very effective and elegant relief to the otherwise
+flat and heavy ceiling. There are three large and fourteen small dining
+tables, the large tables being arranged longitudinally in the central
+part of the saloon, and the small tables at right angles on the sides.
+Each diner has his own revolving arm chair, and accommodation is
+provided for 250 persons at once. A large American organ is fixed at the
+fore end of the room, and opening off through double spring doors at the
+foot of the grand staircase is a handsome American luncheon bar, with
+the usual fittings. On each side of the vessel, from the saloon to the
+after end of the engine room, are placed staterooms providing for 300
+passengers. The arrangements for steerage passengers are of a superior
+description. The berths are arranged in single tiers or half rooms, not
+double, as is usually the custom, each being separated by a passage,
+and having a large side light, thus adding greatly to the light,
+ventilation, and comfort of the steerage passengers, and necessitating
+the advantage of a smaller number of persons in each room. The City
+of Rome is the first of the two due here; she sails from Liverpool on
+October 13.
+
+In the Servia the machinery consists of three cylinder compound surface
+condensing engines, one cylinder being 72 inches, and two 100 inches in
+diameter, with a stroke of piston of 6 feet 6 inches. There are seven
+boilers and thirty-nine furnaces. Practically the Servia is a five
+decker, as she is built with four decks--of steel, covered with yellow
+pine--and a promenade reserved for passengers. There is a music room on
+the upper deck, which is 50 feet by 22 feet, and which is handsomely
+fitted up with polished wood panelings. For the convenience of the
+passengers there are no less than four different entrances from the
+upper deck to the cabins. The saloon is 74 feet by 49 feet, with sitting
+accommodations for 350 persons, while the clear height under the beams
+is 8 feet 6 inches. The sides are all in fancy woods, with beautifully
+polished inlaid panels, and all the upholstery of the saloon is of
+morocco leather. For two-thirds of its entire length the lower deck is
+fitted up with first class staterooms. The ship is divided into nine
+water-tight bulkheads, and she is built according to the Admiralty
+requirements for war purposes. There are in all twelve boats equipped
+as life-boats. The Servia possesses a peculiarity which will add to her
+safety, namely, a double bottom, or inner skin. Thus, were she to
+ground on rocks, she would be perfectly safe, so long as the inner skin
+remained intact. Steam is used for heating the cabins and saloons, and
+by this means the temperature can be properly adjusted in all weathers.
+In every part of the vessel the most advanced scientific improvements
+have been adopted. The Servia leaves Liverpool on October 22.
+
+The Alaska, whose owners, it is understood, are determined to make her
+beat all afloat in speed, does not sail until November 5, and therefore
+it is premature to say anything about her interior equipments. She is
+the sister of the celebrated Arizona, and was built by the well-known
+firm of Elder & Co., on the Clyde.
+
+       *       *       *       *       *
+
+
+
+
+IMPROVED ROAD LOCOMOTIVE.
+
+
+Several attempts have been made to connect the leading wheels of a
+traction engine with the driving wheels, so as to make drivers of all of
+them, and thus increase the tractive power of the engine, and to afford
+greater facilities for getting along soft ground or out of holes. The
+wheels with continuous railway and India-rubber tires have been employed
+to gain the required adhesion, but these wheels have been too costly,
+and the attempts to couple driving and leading wheels have failed. The
+arrangement for making the leading wheels into drivers, illustrated
+on page 4825, has been recently brought out by the Durham and North
+Yorkshire Steam Cultivation Company, Ripon, the design being by Messrs.
+Johnson and Phillips. The invention consists in mounting the leading
+axle in a ball and long socket, the socket being rotated in fixed
+bearings. The ball having but limited range of motion in the socket, is
+driven round with it, but is free to move in azimuth for steering.
+
+This engine has now been in use more than twelve months in traction
+and thrashing work, and, we are informed, with complete success. The
+illustrations represent a 7-horse power, with a cylinder 8 in. diameter
+by 12 in. stroke, and steam jacketed. The shafts and axles are of
+Bowling iron. The boiler contains 140 ft. of heating surface, and is
+made entirely of Bowling iron, with the longitudinal seams welded. The
+gearing is fitted with two speeds arranged to travel at 11/2 and 3 miles
+per hour, and the front or hind road wheels can be put out of gear when
+not required. The hind driving wheels are 5 ft. 6 in. diameter, and the
+front wheels 5 ft.; weight of engine 8 tons.--_The Engineer._
+
+[Illustration: IMPROVED ROAD LOCOMOTIVE]
+
+[Illustration: IMPROVED ROAD LOCOMOTIVE]
+
+       *       *       *       *       *
+
+
+
+
+AMERICAN MILLING METHODS.
+
+[Footnote 1: A paper read before the meeting of the Pennsylvania State
+Millers Association at Pittsburgh, Pa., by Albert Hoppin, Editor of the
+_Northwestern Miller_.]
+
+By ALBERT HOPPIN.
+
+
+To speak of the wonderful strides which the art of milling has taken
+during the past decade has become exceedingly trite. This progress,
+patent to the most casual observer, is a marked example of the power
+inherent in man to overcome natural obstacles. Had the climatic
+conditions of the Northwest allowed the raising of as good winter wheat
+as that raised in winter wheat sections generally, I doubt if we should
+hear so much to-day of new processes and gradual reduction systems. So
+long as the great bulk of our supply of breadstuffs came from the winter
+wheat fields, progress was very slow; the mills of 1860, and I may even
+say of 1870, being but little in advance, so far as processes were
+concerned, of those built half a century earlier. The reason for this
+lack of progress may be found in the ease with which winter wheat could
+be made into good, white, merchantable flour. That this flour was
+inferior to the flour turned out by winter wheat mills now is proven by
+the old recipe for telling good flour from that which was bad, viz.: To
+throw a handful against the side of the barrel, if it stuck there it was
+good, the color being of a yellowish cast. What good winter wheat patent
+to-day will do this? Still the old time winter wheat flour was the best
+there was, and it had no competitor. The settling up of the Northwest
+which could not produce winter wheat at all, but which did produce a
+most superior article of hard spring wheat, was a new factor in the
+milling problem. The first mills built in the spring wheat States tried
+to make flour on the old system and made a most lamentable failure of
+it. I can remember when the farmer in Wisconsin, who liked a good loaf
+of bread, thought it necessary to raise a little patch of winter wheat
+for his own use. He oftener failed than succeeded, and most frequently
+gave it up as a bad job. Spring wheat was hard, with a very tender,
+brittle bran. If ground fine enough to make a good yield a good share
+of the bran went into the flour, making it dark and specky. If not
+so finely ground the flour was whiter, but the large percentage of
+middlings made the yield per bushel ruinously small. These middlings
+contained the choicest part of the flour producing part of the berry,
+but owing to the dirt, germ, and other impurities mixed with them, it
+was impossible to regrind them except for a low grade flour. Merchant
+milling of spring wheat was impossible wherever the flour came in
+competition with winter wheat flours. At Minneapolis, where the millers
+had an almost unlimited water power, and wheat at the lowest price,
+merchant milling was almost given up as impracticable. It was certainly
+unprofitable. To the apparently insurmountable obstacles in the way of
+milling spring wheat successfully, we may ascribe the progress of modern
+milling. Had it been as easy to raise good winter wheat in Wisconsin and
+Minnesota as in Pennsylvania and Ohio, or as easy to make white flour
+from spring as from winter wheat, we should not have heard of purifiers
+and roller mills for years to come.
+
+The first step in advance was the introduction of a machine to purify
+middlings. It was found that the flour made from these purified
+middlings was whiter than the flour from the first grinding and brought
+a better price than even winter wheat flours. Then the aim was to make
+as many middlings as possible. To do this and still clean the bran so
+as to make a reasonable yield the dress of the burrs was more carefully
+attended to, the old fashioned cracks were left out, the faces and
+furrows made smooth, true, and uniform, self-adjusting drivers
+introduced, and the driving gear better fitted. Spring wheat patents
+rapidly rose to the first place in the market, and winter wheat millers
+waked up to find their vantage ground occupied by their hitherto
+contemned rivals. To their credit it may be said that they have not
+been slow in taking up the gauntlet, and through the competition of the
+millers of the two climatically divided sections of this country with
+each other and among themselves the onward march of milling progress has
+been constantly accelerated. Where it will end no man can tell, and
+the chief anxiety of every progressive miller, whether he lives in
+Pennsylvania or Minnesota, is not to be left behind in the race.
+
+The millers of the more Eastern winter wheat States have a two-fold
+question to solve. First, how to make a flour as good as can be found in
+the market, and second, how to meet Western competition, which, through
+cheap raw material and discriminating freight rates, is making serious
+inroads upon the local markets. Whether the latter trouble can be
+remedied by legislature, either State or national, or not, remains to be
+proven by actual trial. That you can solve the first part of the problem
+satisfactorily to yourselves depends upon your readiness to adopt new
+ideas and the means you have at hand to carry them out. It is manifestly
+impossible to make as good a flour out of soft starchy wheat as out of
+that which is harder and more glutinous. It is equally impossible for
+the small mill poorly provided with machinery to cope successfully
+with the large merchant mill fully equipped with every appliance that
+American ingenuity can suggest and money can buy. I believe, however,
+that a mill of moderate size can make flour equally as good as the large
+mill, though, perhaps, not as economically in regard to yield and cost
+of manufacture.
+
+The different methods of milling at present in use may be generally
+divided into three distinct processes, which, for want of any better
+names, I will distinguish as old style, new process, and gradual
+reduction. Perhaps the German division of low milling, half high
+milling, and high milling is better. Old style milling was that in
+general use in this country up to 1870, and which is still followed in
+the great majority of small custom or grist mills. It is very simple,
+consisting of grinding the wheat as fine as possible at the first
+grinding, and separating the meal into flour, superfine or extra,
+middlings, shorts, and bran. Given a pair of millstones and reel long
+enough, and the wheat could be made into flour by passing through the
+two. Because spring wheat was so poorly adapted to this crude process,
+it had to be improved and elaborated, resulting in the new process.
+
+At first this merely consisted of purifying and regrinding the middlings
+made in the old way. In its perfected state it may be said to be halfway
+between the old style and gradual reduction, and is in use now in many
+mills. In it mill stones are used to make the reductions which are only
+two in number, in the first of which the aim of the miller is to make as
+many middlings as he can while cleaning the bran reasonably well, and
+in the second to make the purified middlings into flour. In the most
+advanced mills which use the new process, the bran is reground and the
+tailings from the coarse middlings, containing germ and large middlings
+with pieces of bran attached, are crushed between two rolls. These
+can hardly be counted as reductions, as they are simply the finishing
+touches, put on to aid in working the stuff up clean and to permit of
+a little higher grinding at first. Regarding both old style and new
+process milling, you are already posted. Gradual reduction is newer,
+much more extensive, and merits a much more thorough explanation. Before
+entering upon this I will call your attention to one or two points which
+every miller should understand.
+
+The two essential qualities of a good marketable flour are color and
+strength. It should be sharply granular and not feel flat and soft to
+the touch. A wheat which has an abundance of starch, but is poor in
+gluten, cannot make a strong flour. This is the trouble with all soft
+wheats, both winter and spring. A wheat which is rich in gluten is hard,
+and in the case of our hard Minnesota wheat has a very tender bran.
+It is comparatively easy to make a strong flour, but it requires very
+careful milling to make a flour of good color from it. Probably the
+wheat which combines the most desirable qualities for flour-making
+purposes is the red Mediterranean, which has plenty of gluten and a
+tough bran, though claimed by some to have a little too much coloring
+matter, while the body of the berry is white. By poor milling a good
+wheat can be made into flour deficient both in strength and color, and
+by careful milling a wheat naturally deficient in strength may be made
+into flour having all the strength there was in the wheat originally and
+of good color. Good milling is indispensable, no matter what the quality
+of the wheat may be.
+
+The idea of gradual reduction milling was borrowed by our millers from
+the Hungarian mills. There is, however, this difference between the
+Hungarian system and gradual reduction, as applied in this country, that
+in the former, when fully carried out, the products of the different
+breaks are kept separate to the end, and a large number of different
+grades of flour made, while in the system, as applied in this country,
+the separations are combined at different stages and usually only three
+different grades of flour made, viz.: patent, baker's, or as it is
+termed in Minnesota, clear flour, and low grade or red dog. In the
+largest mills the patent is often subdivided into first and second, and
+they may make different grades of baker's flour, these mills approaching
+much nearer to the Hungarian system, though modifying it to American
+methods and machinery. In mills of from three to five hundred barrels
+daily capacity, it is hardly possible or profitable to go to this
+subdivision of grades, owing to the excessive amount of machinery
+necessary to handling the stuff in its different stages of completion.
+The Hungarian system has, therefore, been greatly modified by American
+millers and milling engineers to adapt it to the requirements of mills
+of average capacity. This modified Hungarian system we call gradual
+reduction. It can be profitably employed in any mill large enough to run
+at all on merchant work. So far it has not been found practicable to use
+it in mills of less than one hundred and twenty-five to one hundred and
+fifty barrels capacity in twenty-four hours, and it is better to have
+the mill of at least double this capacity.
+
+Gradual reduction, as its name implies, consists in reducing the
+wheat to flour, shorts, and bran, by several successive operations or
+reductions technically called breaks, the process going on gradually,
+each break leaving the material a little finer than the preceding one.
+Usually five reductions or breaks are made, though six or seven may be
+used. The larger the number of breaks the more complicated the system
+becomes, and it is preferable to keep it as simple as possible, for even
+at its simplest it requires a good, wide-awake thinking miller to handle
+it successfully. When it is thoroughly and systematically carried out in
+the mill it is without question as much in advance of the new process as
+that is ahead of the old style of milling.
+
+In order that I may convey to you as clear an idea of gradual milling
+reduction as possible, I will give as fully as possible the programme of
+a mill of one hundred and fifty barrels maximum daily capacity designed
+to work on mixed hard and soft spring wheat, and which probably will
+come much nearer to meeting the conditions under which you have to mill
+than any other I have found readily obtainable. I have chosen a mill of
+this size, first, because following out the programme of a larger one
+would require too much time and too great a repetition of details and
+not give you any clearer idea of the main principles involved, and
+secondly, because I thought it would come nearer meeting the average
+requirements of the members of your association. Your worthy secretary
+cautioned me that I must remember that I was going to talk to winter
+wheat millers. The main principles and methods of gradual reduction are
+the same, whether applied to spring or winter wheat; the details may
+have to be varied to suit the varying conditions under which different
+mills are operated. For this programme I am indebted to Mr. James Pye,
+of Minneapolis, who is rapidly gaining an enviable and well deserved
+reputation as a milling engineer, and one who has given much study to
+the practical planning and working of gradual reduction mills.
+
+And right here let me say that no miller should undertake to build
+a gradual reduction mill, or to change over his mill to the gradual
+reduction system, until he has consulted with some good milling engineer
+(the term millwright means very little nowadays), and obtained from him
+a programme which shall fit the size of the mill, the stock upon which
+it has to work, and the grade of flour which it is to make. This
+programme is to the miller what a chart is to the sailor. It shows him
+the course he must pursue, how the stuff must be handled, and where it
+must go. Without it he will be "going it blind," or at best only feeling
+his way in the dark. A gradual reduction mill, to be successful, must
+have a well-defined system, and to have this system, the miller must
+have a definite plan to work by. But to go on with my programme.
+
+The wheat is first cleaned as thoroughly as possible to remove all
+extraneous impurities. In the cleaning operations care should be taken
+to scratch or abrade the bran as little as possible, for this reason:
+The outer coating of the bran is hard and more or less friable. Wherever
+it is scratched a portion is liable to become finely comminuted in the
+subsequent reductions, so finely that it is impossible to separate it
+from the flour by bolting, and consequently the grade of the latter is
+lowered. The ultimate purpose of the miller being to separate the flour
+portion of the berry from dirt, germ, and bran it is important that he
+does not at any stage of the process get any dirt or fine bran speck or
+dust mixed in with his flour, for if he does he cannot get rid of it
+again. So it must be borne in mind that at all stages of flouring, any
+abrasion or comminution of the bran is to be avoided as far as possible.
+
+After the wheat is cleaned, it is by the first break or reduction split
+or cut open, in order to liberate the germ and crease impurities. As
+whatever of dirt is liberated by this break becomes mixed in with the
+flour, it is desirable to keep the amount of the latter as small as
+possible. Indeed, in all the reductions the object is to make as little
+flour and as many middlings as possible, for the reason that the latter
+can be purified, while the former cannot, at least by any means at
+present in use. After the first break the cracked wheat goes to a
+scalping reel covered with No. 22 wire cloth. The flour, middlings,
+etc., go through the cloth, and the cracked wheat goes over the tail of
+the reel to the second machine, which breaks it still finer. After this
+break the flour and middlings are scalped out on a reel covered with
+No. 22 wire cloth. The tailings go to the third machine, and are still
+further reduced, then through a reel covered with No. 24 wire cloth. The
+tailings go to the fourth machine, which makes them still finer, then
+through a fourth scalping reel the same as the third. The tailings from
+this reel are mostly bran with some middlings adhering, and go to the
+fifth machine, which cleans the bran. From this break the material
+passes to a reel covered with bolting cloth varying in fineness from No.
+10 at the head to No. 00 at the tail. What goes over the tail of this
+reel is sent to the bran bin, and that which goes through next to the
+tail of the reel, goes to the shorts bin. The middlings from this reel
+go to a middlings purifier, which I will call No. 1, or bran middlings
+purifier. The flour which comes from this reel is sent to the chop reel
+covered at the head with say No. 9, with about No. 5 in the middle and
+No 0 at the tail. You will remember that after each reduction the flour
+and middlings were taken out by the scalping reels. This chop, as it is
+now called, also goes to the same reel I have just mentioned. The
+coarse middlings which go over the tail of this reel go to a middlings
+purifier, which I will designate as No. 2. These go through the No. 0
+cloth at the tail of the reel purifier No. 3; those which go through No.
+5 cloth got to purifier No. 4; while all that goes through the No. 9
+cloth at the head of the reel is dropped to a second reel clothed with
+Nos. 13 to 15 cloth with two feet of No. 10 at the tail. The flour from
+this reel goes to the baker's flour packer; that which drops through the
+No. 10 is sent to the middlings stone, while that which goes over the
+tail of the reel goes to purifier No. 4. We have now disposed of all the
+immediate products of the first five breaks, tracing them successively
+to the bran and shorts bins, to the baker's flour packer and to the
+middlings purifiers, a very small portion going to the middlings stone
+without going through the purifiers.
+
+The middlings are handled as follows in the purifiers. From the No. 1
+machine, which takes the middlings from the fifth break, the tailings go
+to the shorts bin, the middlings which are sufficiently well purified go
+to the middlings stone, while those from near the tail of the machine
+which contain a little germ and bran specks go to the second germ rolls,
+these being a pair of smooth rolls which flatten out the germ and crush
+the middlings, loosening adhering particles from the bran specks. From
+the second germ rolls the material goes to a reel, where it is separated
+into flour which goes into the baker's grade, fine middlings which are
+returned to the second germ rolls at once, some still coarser which go
+to a pair of finely corrugated iron rolls for red dog, and what goes
+over the tail of the reel goes to the shorts bin. The No. 2 purifier
+takes the coarse middlings from the tail of the first or chop reel as
+already stated. The tailings from this machine go to the shorts bin,
+some few middlings from next the tail of the machine are returned to the
+head of the same machine, while the remainder are sent to the first germ
+rolls. The reason for returning is more to enable the miller to keep a
+regular feed on the purifiers than otherwise. The No. 3 purifier takes
+the middlings from the 0 cloth on the chop reel. From purifier No. 3
+they drop to purifier No. 5. A small portion that are not sufficiently
+well purified are returned to the head of No. 3, while those from the
+head of the machine, which are well purified, are sent to the middlings
+stones. The remainder, which contain a great deal of the germ, are taken
+to the first germ rolls, in passing which they are crushed lightly to
+flatten the germ without making any more flour than necessary. The No. 4
+purifier takes the middlings from No. 2 and also from No. 5 cloth on
+the chop reel and from the No. 10 on the tail of the baker's reel. The
+middlings from the head of this machine go to the middlings stones, and
+the remainder to purifier No. 6. The tailings from Nos. 3, 4, 5, and 6
+go to the red dog rolls. A small portion not sufficiently well purified
+are returned from No. 6 to the head of No. 4, while the cleaned
+middlings go to the middlings stones.
+
+The portions of the material which have not been traced either to the
+baker's flour or the bran and shorts bins are the middlings which have
+gone to the middlings stones, the germy middlings which have gone to the
+first germ rolls, and the tailings from purifiers Nos. 3, 4, 5, and 6,
+and some little stuff not quite poor enough for shorts from the reel
+following the second germ rolls. Taking these _seriatim_: the middlings
+after passing through the middlings stones, go to the first patent reel
+covered with eleven feet of No. 13 and four feet of No. 8. The flour
+from the head of the reel goes to the patent packer, that from the
+remainder of the reel is dropped to another reel, while the tailings go
+to the No. 4 purifier. The lower patent reel is clothed with No. 14 and
+two feet of No. 10 cloth; from the head of the reel the flour goes to
+the patent packer, the remainder that passes through the No. 10 cloth
+which will not do to go into the patent, being returned to the middlings
+stones, while the tailings are sent to the No. 4 purifier.
+
+The germ middlings, after being slightly crushed as before stated, are
+sent to a reel covered with five feet of No. 13 cloth, five feet of No.
+14, and the balance with cloth varying in coarseness from No. 7 to No.
+00. The flour from this reel goes into the patent, the tailings to the
+red dog rolls, the middlings from next the tail of the reel which still
+contain some germ to the second germ rolls, while the middlings which
+are free from germ go to the middlings stones.
+
+The tailings from purifiers 3, 4, 5, and 6, the material from the reel
+following the second germ rolls, which is too good for shorts, but not
+good enough to be returned into middlings again, and the tailings from
+the reel following the first germ rolls are sent to the red dog rolls,
+which, as I have stated, are finely corrugated. Following these rolls is
+the red dog reel. The flour goes to the red dog bin, the tailings to
+the shorts bin, while some stuff intermediate between the two, not fine
+enough for the flour but too good for shorts, is returned to the red dog
+rolls.
+
+This finishes the programme. I have not given it as one which is exactly
+suited to winter wheat milling. However, as I said before, the general
+principles are the same in either winter or wheat gradual reduction
+mills, and the various systems of gradual reduction, although they
+differ in many points, and although there are probably no two engineers
+who would agree as to all the details of a programme, the main ideas
+are essentially the same. The system has been well described as one of
+gradual and continued purification. In the programme above given the
+idea was to fit up a mill which should do a maximum amount of work of
+good quality with a minimum amount of expenditure and machinery. In a
+larger mill or even in a mill of the same capacity where money was not
+an object, the various separations would probably be handled a little
+differently, the flour and middlings from the first and fifth breaks
+being handled together, and those from the second, third, and fourth
+breaks being also handled together. The reason for this separation being
+that the flour from the first and fifth breaks contain, the first a
+great deal of crease dirt, and the fifth more bran dust than that from
+the other breaks, the result being a lower grade of flour. The object
+all along being to keep the amount of flour with which dirt can get
+mixed as small as possible, and not to lower the grade of any part of
+the product by mixing it with that which is inferior, always bearing in
+mind that the aim is to make as many middlings as possible, for they can
+be purified while the flour can not, and that whenever any dirt is once
+eliminated it should be kept out afterwards. This leads me to say that
+if a miller thinks the adoption of rolls or reduction machines is all
+there is of the system, he is very much mistaken. If anything, more of
+the success of the mill depends upon the careful handling of the stuff
+after the breaks are made, and here the miller who is in earnest to
+master the gradual reduction system will find his greatest opportunities
+for study and improvement. A few years back it was an axiom of the trade
+that the condition of the millstone was the key to successful
+milling. This was true because the subsequent process of bolting was
+comparatively simple. Now the mere making of the breaks is a small
+matter compared with the complex separations which come after. In
+the foregoing programme we had five breaks or successive reductions.
+Although this is better than a smaller number, I will here say that
+it is not absolutely essential, for very good work is done with four
+breaks. The mill for which this programme was made, including the
+building, cost about $15,000, and is designed to make about sixty per
+cent. of patent, thirty-five per cent. of baker's, and five per cent.
+of low grade, results which are in advance of many larger and more
+pretentious mills.
+
+One difficulty in the way of adapting the gradual reduction system to
+mills of very small capacity is that the various machines require to be
+loaded to a certain degree in order to work at their best. It is only a
+matter of short time when our milling inventors will design machinery
+especially for small mills; in fact they are now doing it, and every
+day brings it more within the power of the small miller to improve his
+manner of milling. To show what can be done in this direction I will
+briefly describe a mill of about ninety barrels maximum capacity per
+twenty-four hours, which is as small as can be profitably worked. I will
+premise this description by saying it is designed with a view to the
+greatest economy of cost, the best trade of work, and to reduce the
+amount of machinery and the handling of the stuff as much as possible.
+This latter point is of much importance in any mill, either large or
+small, no matter upon what system it is operated, for it takes power to
+run elevators and conveyors, and especially in elevating and conveying
+middlings, especially those made from winter wheat, their quality is
+inured and a loss incurred, by the unavoidable amount of flour made by
+the friction of the particles against each other. So much is this the
+case that in one of our largest mills it is deemed preferable to move
+the middlings from one end of the mill to the other by means of a hopper
+bin on a car which runs on a track spiked to the floor, rather than to
+employ a conveyor. A mill built as I am going to describe would require
+from fifty to sixty horse-power to run it, and including steam power and
+building would cost from $10,000 to $12,000, according to location. I
+give it as of interest to those among your number who own small mills
+and may contemplate improving them.
+
+The building is four stories high, including basement, and thirty-two
+feet square. It would be some better to have it larger, but it is made
+this small to show how small a space a mill of this size can be made to
+occupy. No story is less than twelve feet high. The machinery Is very
+conveniently arranged, and there is plenty of room all around. The
+system is a modification of the gradual reduction system, the middlings
+being worked upon millstones. The first break is on one pair of 9 x
+18 inch corrugated iron rolls, eight corrugations to the inch, the
+corrugations running parallel with the axis of the rolls. The second
+break on rolls having twelve corrugations to the inch, the third
+sixteen, and the fourth twenty to the inch, while the fifth break, where
+the bran is finally cleaned, has twenty-four corrugations to the inch.
+The basement contains the line shaft and pulleys for driving rolls,
+stones, cockle machine, and separator. The only other machinery in the
+basement is the cockle machine. The line shaft runs directly through
+the center of the basement, the power being from engine or water wheel
+outside the building. The first floor has the roller mills in a line
+nearly over the line shaft below, the middlings stones, two in number,
+at one side opposite the entrance to the mill, the receiving bin at
+one side of the entrance in the corner of the mill, and the two flour
+packers for the baker's and patent flour in the other corner. This
+arrangement leaves over half of the floor area for receiving and packing
+purposes. The bolting chests, one with six reel and the other with three
+reel begin on the second floor and reach up into the attic. An upright
+shaft from the line shaft in the basement geared to a horizontal shaft
+running through the attic parallel with the line shaft below, comprise
+about all the shafting there is in the mill. There is a short shaft on
+the second floor from which the two purifiers on this floor and the two
+in the attic are driven, and another short shaft on the first floor to
+drive the packers. There are four purifiers, two on the second floor,
+and two more directly over them in the attic. The elevator heads are all
+directly upon the attic line shaft, and the bolting chests are driven by
+uprights dropped from this shaft. The combined smutter and brush machine
+is on the third floor at one end of the bolting chests and directly over
+the stock hoppers. This comprises all the machinery in the mill. The
+programme is about as follows:
+
+The break reels are clothed as follows: First break No. 20, wire cloth,
+second break No. 22, third break No. 24, and fourth break No. 24. The
+material passing through these scalping reels, now called chop, goes to
+a series of reels, the first clothed with Nos. 6, 4, and 0. The material
+passing over the tail is sent to the germ purifier, that passing through
+Nos. 4 and 0, to the coarse middlings purifier, and that through the No.
+6 goes to the reel below clothed with Nos. 12 and 13. Some nice granular
+flour is taken off from this reel; the remainder, which passes over the
+tail and through the cutoffs, goes to the next reel below clothed with
+Nos. 14, 15, and 9. Some good flour comes from the 14 and 15; that which
+passes through the 9 goes at once to the stones without purifying, while
+that which passes over the tail is sent to the fine middlings purifiers.
+
+After the purification, the middlings are ground on stones and bolted
+on Nos. 13 and 14 cloth, after having been scalped on No 8. The germ
+middlings are crushed on smooth rolls and bolted on Nos. 12 and 13. What
+is not crushed fine enough goes with poor tailings to the second germ
+rolls, and from these to a reel by themselves or to the fifth reduction
+or bran reel. A mill of this kind could be made much more perfect by an
+expenditure of two or three thousands dollars more. I have instanced it
+to show what can be done with gradual reduction in a very small way.
+
+In mills of from three hundred to five hundred barrels capacity and
+still larger, the programme differs considerably from that I have
+sketched, the middlings being graded and handled with little, if any,
+returning, and are sized down on the smooth rolls, a much larger
+percentage of the work of flouring being done on millstones. For a three
+hundred barrel roller mill, the following plant is requisite: five
+double corrugated roller mills, five double smooth roller mills, three
+pairs of four foot burrs sixteen purifiers, four wire scalping reels,
+six feet long, one reel for the fifth break, one reel for low grade
+flour, eight chop reels, seven reels for flour from smooth rolls, three
+reels for the stone flour, two grading reels, three flour packers, and
+necessary cleaning machinery. The reels are eighteen feet thirty-two
+inches. The programme is necessarily more complicated.
+
+When it comes to the machinery to be employed in making the reductions
+or breaks, the miller has several styles from which to choose. Which is
+best comes under the head of what I don't know, and moreover, of that
+which I have found no one else who does know. Each machine has its good
+points, and the mill owner must make his own decision as to which is
+best suited to his purpose. The main principles involved are to abrade
+the bran as little as possible while cleaning it thoroughly, and to make
+as little break flour, and as many middlings as possible, the latter to
+be made in such shape as to be the most easily purified. Regarding
+the difference between spring and winter wheat for gradual reduction
+milling, it may be stated something after this manner: Spring wheat
+has a thinner and more tender bran, makes more middlings because it is
+harder, and for the same reason the flour is more inclined to be coarse
+and granular. In milling with winter wheat, especially the better
+varieties, there will be more break flour made, the middlings will be
+finer with fewer bran specks, and the bran more easily cleaned, because
+it will stand harsher treatment. Winter wheat, moreover, requires more
+careful handling in making the breaks, not because of the bran, but to
+avoid breaking down the middlings, and making too much and too fine and
+soft break flour. In order to keep the flour sharp and granular, coarser
+cloths are used in bolting, and because the middlings are finer the
+bolting is not so free and a larger bolting surface is required. In
+milling either spring or winter wheat there should be ample purifying
+capacity, it being very unwise to limit the number of machines, so that
+any of them will be overtaxed. The day has gone by when one purifier
+will take care of all the middlings in the mill.
+
+There is one point which is of much interest to mill owners who wish to
+change their mills over to the gradual reduction process, that is, how
+far they can utilize their present plan of milling machinery in making
+the change. Of course the cleaning machinery is the same In both cases,
+so are the elevators, conveyors, bolting chests, etc. But to use the
+millstone is a debatable question. After carefully considering the
+matter I have come to the conclusion that it has its place, and an
+important one at that, under the new regime, viz., that of reducing
+the finer purified middlings to flour. The reason for this lies in the
+peculiar construction of the wheat berry. If the interior of the berry
+were one solid mass of flour, needing only to be broken up to the
+requisite fineness, it could be done as well on the rolls. But instead
+of this, as is well known, the flour part of the berry is made up of
+a large number of granules or cells, the walls of which are cellular
+tissue, different from the bran in that it is soft and white instead of
+hard and dark colored. It is also fibrous to a certain extent, and when
+the fine middlings are passed between the rolls instead of breaking
+down and becoming finer, it has a tendency to cake up and flatten out,
+rendering the flour soft and flaky. It does not hurt the color, but it
+does hurt the strength. When the millstone is used in place of the roll
+the flour is of equally good color, and more round and granular. I
+know that in this the advocates of smooth rolls will differ from my
+conclusions, but I believe that the final outcome will be the use of
+millstones on the finer middlings, and in fact on all the middlings that
+are thoroughly freed from the germ.
+
+It has been said that that which a man gives the most freely and
+receives with the worst grace is advice. I will, however, close with a
+little of the article which may not be wholly put of place. If you have
+a mill do not imagine that the addition of a few pairs of rolls, a
+purifier or two, and a little overhauling of bolting-chests, is going to
+make it a full-fledged Hungarian roller mill. If you are going to change
+an old mill or build a new one, do not take the counsel or follow the
+plans of every itinerant miller or millwright who claims to know all
+about gradual reduction. No matter what kind of a mill you want to
+build, go to some milling engineer who has a reputation for good work,
+tell him how large a mill you want, show him samples of the wheat it
+must use and the grades of flour it must make, and have him make a
+programme for the mill and plan the machinery to fit it. Then have the
+mill built to fit the machinery. When it starts follow the programme,
+whether it agrees with your preconceived notions or not, and the mill
+will, in ninety-nine cases out of one hundred, do good work.
+
+       *       *       *       *       *
+
+
+MACHINE FOR DOTTING TULLES AND OTHER LIGHT FABRICS.
+
+Dotted or chenilled tulles are fabrics extensively used in the toilet
+of ladies, and the ornamentation of which has hitherto been done by
+the application to the tissue, by hand, either of chenille or of small
+circles previously cut out of velvet. This work, which naturally takes
+considerable time, greatly increases the cost price of the article.
+
+A few trials at doing the work mechanically have been made, but without
+any practical outcome. The workwomen who do the dotting are paid at
+Lyons at the rate of 80 centimes per 100 dots; so that if we take
+tulle with dots counter-simpled 0.04 of an inch, which is the smallest
+quincunx used, and suppose that the tissue is 31 inches wide and that
+the daily maximum production is one yard, we find that 400 dots at 80
+centimes per 100 = 3 francs and 20 centimes (about 63 cents), the cost
+of dotting per yard. It is true that the workwoman furnishes the velvet
+herself.
+
+Mr. C. Ricanet, of Lyons, has recently invented a machine with which he
+effects mechanically the different operations of dotting, not only on
+tulles but also upon gauzes or any other light tissues whatever, such
+as those of cotton, silk, wool, etc. Aided by a talented mechanic, Mr.
+Ricanet has succeeded in constructing one of those masterpieces of
+wonderfully accurate mechanism of which the textile industry appears
+to have the monopoly--at least it is permissible to judge so from the
+remarkable inventions of Vaucanson, Jacquard, Philippe de Girard,
+Heilmann, and others.
+
+The object of this new machine, then, which has been doing its wonderful
+work for a few days only, is to reproduce artificially chenille
+embroidered on light tissues, by mechanically cutting out and gluing
+small circles of velvet upon these fabrics.
+
+For this purpose all kinds of velvet may be employed, and, in order to
+facilitate the cutting, they are previously coated on the reverse side
+with any glue or gum whatever, which gives the velvet a stiffness
+favorable to the action of the punch. To effect the object desired the
+apparatus has three successive operations to perform: first, cutting the
+circles; second, moistening; and third, fastening down the dots upon the
+tissue according to a definite order and spacing. The machine may be
+constructed upon any scale whatever, although at present it is only made
+for operating on pieces 31 inches wide, that being the normal width of
+dotted tulles. The quincuncial arrangement of the dots is effected by
+the punching, moistening, and fastening down of odd and even dots,
+combined with the forward movement of the tissue to be chenilled.
+
+The principal part of the machine is the cam-shaft, A (Figs. 1, 2, and
+3), which revolves in the direction of the arrows and passes in the
+center of 80 cam-wheels, 40 of which are odd and 40 even, alternately
+opposed to each other. This shaft actuates, through its two extremities,
+the different combined motions in view of the final object to be
+attained, and also carries the motive pulleys, PP'. Figs. 1 and 2 show
+the profile of two of these opposed cam-wheels--the arrangement by means
+of which two rows of dots (odd and even) are laid down upon the tissue
+during one revolution of the shaft or drum, A. Each of the wheels
+carries three cams (Figs. 1 and 3), the first, (_a_), corresponding to
+the punching; the second, (_a'_), to the moistening, and the third,
+(_a''_), to the gluing down of the dots.
+
+The annexed figure, one-quarter actual size, shows in section the
+details of the cutting mechanism. To each cam-wheel there corresponds
+one punch, and the eighty punches are arranged side by side and parallel
+upon a shaft, B, a spring, _b_, holding them constantly against the
+circumference of the cam-wheels. In Fig. 2 only one of these details is
+shown. The punching arrangement consists of an ordinary punch, _c_, of
+variable diameter, screwed to the extremity of a tube, _d_, which is
+itself suspended from the end of the lever, _p_, but which can receive
+from it at the desired moment the pressure necessary to effect the
+cutting. The vertical position of these multiple tubes is insured by
+a guide, _e_, which is thoroughly indispensable. Through each of the
+tubes, _d_, there passes a plunger designed for expelling from the punch
+the piece that has been cut out of the velvet, and for gluing it down to
+the fabric. The two small springs, _b'_ and _b''_, tend continually to
+lift the tubes as well as the plunger. The whole mechanism is affixed to
+solid cast-iron frames, and the machine itself may be mounted on wooden
+supports or a metal frame.
+
+The punching is effected on a bronze straight-edge, C, which slides in a
+cast-iron channel, D. This presents alternately, in its movement, entire
+and punctured spaces, the former for receiving the blow of the punch and
+the latter for allowing passage at the desired moment to the plunger
+as it goes to fasten the dots upon the tulle which is passing along
+underneath the channel, D. The punching is done primarily and
+principally by pressure, but, in order to facilitate the complete
+detachment of filaments which might retain the punched-out piece, the
+punch is likewise given at the same time a slight rotary motion, thus
+imitating mechanically what is performed by hand in the maneuver of all
+punches. This rotary motion is communicated to the punches by means of
+levers actuated by an eccentric, E, and which move the frame, _h_, whose
+bars engage with the horizontal lever, _g_, soldered to the tube, _d_,
+thus causing the latter at the very moment the punch descends to revolve
+from right to left. The forty punches in operation cause the frame to
+return to its initial position through the action of the springs, _b'_.
+We say forty, since the inventor, in principle, has admitted 80 punches,
+operating 40 as odd and 40 as even; obtaining in this way a dotting in
+a regular quincunx of one yard, that is to say, 80 dots arranged in two
+rows on a fabric 31 inches wide. But it is evident that a much larger
+quincunx may be had by putting in play only a half, a third, or a
+fourth of the punches, and causing the tulle and velvet to advance
+proportionally. For this purpose it is only necessary to unscrew the
+punches which are not to act, and to substitute for the ratchet wheel
+which controls the unrolling of the I tulle, another having a number of
+teeth proportioned to the desired spacing of the dots.
+
+The punching having been executed, and the drum, A, continuing to
+revolve, the punches rise a little owing to the conformation of the
+cam-wheel, and through the action of the springs, _b_, and allow the
+moistener to move forward to dampen the little circles which remain at
+the orifice of the punches. The moistener or dampener is a sort of pad
+equal in length to the field of action of the punches, and is affixed
+to a cross-bar, F, which is connected at its two extremities with the
+levers, G, that are actuated by the cam-wheels, H. These cam-wheels, or
+eccentrics, H, which are mounted on the shaft of the drum, A, cause the
+moistener to move forward as soon as the punches rise after operating,
+and, when it arrives beneath the punches, the larger cams, _a_, of
+the cam-wheels, A, press the latter upon the pad and thus effect the
+dampening of the circles of velvet.
+
+Immediately afterwards, the same eccentrics, H, acting on a lever, I,
+uncover the holes in the straight-edge, C, and the channel, D. The
+large cams, _a"_, of the wheel, A, then acting very powerfully upon the
+respective punches, cause these latter to pass through the orifices so
+that the extremity of each punch comes within about one twenty-fifth of
+an inch of the fabric to be dotted. In this passage of the tube, _d_, a
+small rod, _i_, connected by a lever with the plunger, _f_, is made to
+abut against the guide, _e_, thus causing the descent of the plunger to
+a sufficient degree to push the velvet "dot" out of the tube and to glue
+it upon the fabric. The manner in which these operations are performed
+being now well enough understood, let us for a moment examine the
+motions of the fabrics to be cut and dotted--the first being velvet or
+any other material, even metal (goldleaf, for example), and the second,
+the tulle.
+
+The latter has but one motion, and that is in the direction of its
+length, while the velvet has, in addition to this same motion, another
+slight one from right to left in the direction of its width in order to
+diminish waste as much as possible.
+
+The tulle to be dotted is first wound around a roller, R, from whence it
+passes over the glass guide-roller, R', and between the channel, D, and
+the table, T, to the roller, R", which is heated by steam.
+
+The hot air which is radiated dries the dots, and from thence the fabric
+is taken up by other rollers or by any other method. The steam roller,
+R", carries at one of its extremities a ratchet wheel whose teeth vary
+in number according to the greater or less rapidity with which the tulle
+is unrolled. It is actuated by a lever which receives its motion from
+the eccentric, K.
+
+[Illustration: IMPROVED MACHINE FOR DOTTING TULLAND OTHER LIGHT
+FABRICS.]
+
+In the table, T, there is a rectangular receptacle, _t_, containing
+rasped or powdered velvet for the purpose of forming a reverse of the
+dot. This powder attaches itself to the gum and imitates on the wrong
+side of the fabric a dot similar to that on the upper or right side. The
+velvet is wound upon the roller, _r_, and from thence passes under the
+guiding roller, _r'_, the punches, and the second roller, _r"_. These
+two latter rollers are solidly connected by a straight-edge fixed at the
+extremity of the lever, L, whose other end is in continuous correlation
+with the eccentric, M, which controls the lateral displacements;
+while the eccentric, O, actuates, by means of the screw, Q, and the
+ratchet-wheel, S, the longitudinal advance of the velvet. The eccentric,
+M, is fixed upon an axle, A', which carries a wheel, U, having teeth
+inclined with respect to its axis, and which derives its motion from the
+Archimedean screw, N, fixed at one of the extremities of the cam-shaft,
+A.
+
+We have stated above that the maximum daily hand production of tulle
+dotted in quincunxes of 0.04 of an inch is about one yard. At the rate
+of 30 revolutions per minute, and for the same article as that just
+mentioned, this dotting machine is capable of producing, theoretically,
+360 yards per 10 hours; but practically this production is reduced to
+about 250 yards, which, however, is sufficiently satisfactory.
+
+       *       *       *       *       *
+
+
+
+
+THE REPRODUCTION AND MULTIPLICATION OF NEGATIVES.
+
+By ERNEST EDWARDS, B.A.
+
+
+A question, relative to the subject of reproducing negatives, which was
+put at a meeting of one of your New York societies, prompts me to make a
+few remarks on the subject.
+
+Among the numerous and widely diversified ramifications of our business
+(the Heliotype Printing Company) we have very often to reproduce and
+multiply negatives in both a direct and reversed form. Various methods
+for doing this have been tried, and I may here say that I am quite well
+aware of all the methods that have hitherto been suggested for the
+purpose, but that which I am to describe is the one to which preference
+has been given, and which is that known as the carbon process.
+
+A sheet of carbonized paper or "tissue," having been sensitized by
+immersion in a bath of bichromate of potash, is dried in the dark and
+placed away for future use, although it is undesirable that it be kept
+for more than four or five days. This is placed in a printing frame in
+contact with the negative and exposed for a few minutes, after which it
+is immersed in water, squeegeed down upon a glass plate, and developed
+with warm water in the way so well known to carbon printers. The result
+is a transparency which, owing to having received a sufficient exposure,
+should show every detail of the negative. The nature of the tissue
+employed for such a purpose must be such as to give no strong contrasts,
+but everything reproduced with soft and fine gradation of tone.
+
+The transparency thus obtained forms the _cliche_ by which the negatives
+are subsequently made; and a negative of any size may be obtained by
+the camera on wet or dry plates. The transparency must, of course, be
+pointed to the sky and the light transmitted through it, no other light
+being allowed to reach the lens except that which passes through the
+carbon transparency. Care must also be taken that the transparency is
+_uniformly_ lighted. If it is not possible to obtain a northern light,
+which is best, a reflector of white paper or card may be used which must
+be sufficiently large and placed at an angle of about forty-five degrees
+to the transparency.
+
+If the repeated negative is to be of the same size as the original it
+may be readily produced by repeating the operation of printing on carbon
+tissue, using the transparency in place of the negative, or using a dry
+plate in place of the tissue. But on the whole I have satisfied myself
+that the best results are to be obtained by the first method. There is
+a greater softness in the latter method, but a greater character and
+similarity to the original in the former method. There is no doubt that
+the use of the carbon transparency removes the hardness and riffidness
+of the outlines peculiar to the older method of a collodion
+transparency, while with carbon as the medium it is difficult for
+any but the most experienced eye to distinguish the copy from the
+original.--_Photo Times._
+
+       *       *       *       *       *
+
+
+
+
+A NEW METHOD OF MAKING GELATINE EMULSION.
+
+
+Since gelatine emulsion first came into use one of the greatest troubles
+in connection with the manufacture of it has been that of washing.
+According to the first methods the time taken for this part of the
+process was, I believe, about twenty-four hours. It was very much
+reduced and the ease of manufacture greatly facilitated by the methods
+now most generally used, and which were, I believe, first communicated
+by Messrs. Wratten and Wainright. I refer to those of precipitating with
+alcohol and of straining the emulsion, when set, through canvas, so
+as to divide it very finely. When the latter method is resorted to a
+comparatively short time is sufficient to wash it. This method, although
+a great improvement upon the older ones, yet leaves much to be desired,
+especially for those who are not in the habit of making emulsion
+regularly, but only an occasional batch. When the weather is at all warm
+it takes a long time for the emulsion to set, unless ice be used, and
+when once it is set the washing process is an exceedingly "messy" one
+unless the water be cooled with ice; and the amount of water taken up
+during washing is often so great that there is considerable difficulty
+in getting the emulsion to set on the plates. In fact, even in cold
+weather, it is not an easy process to conduct in the necessary near
+approach to total darkness.
+
+Considerable suspicion has of late been thrown upon the thoroughness of
+the alcohol method, unless the emulsion has, previous to precipitation,
+been freed of the greater part of the soluble salts by washing; that is
+to say, it is doubtful whether the whole of the soluble salts can be
+eliminated by the process, and, therefore, unless in exceptionally hot
+weather, it would seem best not to trust to it, except as a further
+security against soluble bromide and nitrate after washing. Besides
+this, the consumption of alcohol is very large. Almost three times the
+amount of the emulsion precipitated is required, and this, even when
+methylated spirit is used, adds considerably to the expense. With a view
+of doing away with the washing altogether, or, rather, of washing of
+the silver bromide when not incorporated with the gelatine, several
+processes have been invented. By these silver bromide is obtained in a
+very fine state of division, ready to mix with gelatine and water in any
+proportion.
+
+The best known of them is Captain Abney's very ingenious glycerine
+method, which seems to have been thoroughly successful in his hands,
+although it has not been in every one's. The silver bromide obtained by
+his process is not highly sensitive, and requires boiling with gelatine
+before it is in a fit state to make a rapid plate.
+
+We have lately had described in these columns a method of obtaining
+bromide in a highly-sensitive state by means of the use of an acid,
+whereby, after emulsifying and boiling, the viscosity of the gelatine
+was destroyed, and the bromide in time deposited itself. During the late
+hot weather, when washing became almost impossible, I was led to cast
+about for some method of eliminating the soluble salts less tedious and
+"sloppy" than that of washing, more certain and less expensive than that
+of precipitating the whole of gelatine with alcohol, and which would
+take less time than the method of obtaining the bromide in a pure form.
+
+My first idea was to make up the solutions used in emulsifying in a very
+concentrated form, and, after emulsifying, boiling, and allowing to
+cool, to add to the thin emulsion thus obtained gelatine to the amount
+of twenty grains to the ounce, and to precipitate this with alcohol,
+the rest of the gelatine required to make up the bulk being afterwards
+added, and the whole thoroughly incorporated by warming and shaking.
+I was thus successful in reducing the amount of alcohol required to
+one-third of what would be necessary if the whole of the emulsion were
+precipitated; but still I found that, if a reliable emulsion were
+required, the pellicle as formed had to be washed to free it from the
+last trace of soluble salts.
+
+It now struck me that it might be possible to precipitate the bromide of
+silver direct from a very weak solution of gelatine, and obtain it in
+such a form that it might be filtered, washed, and in every way treated
+as an ordinary precipitate. I tried the following experiment. I took--
+
+    1. Silver nitrate....................... 200  grains
+        Water...............................   11/2 ounce.
+    2. Ammonia bromide...................... 120  grains.
+       Water................................   11/2 ounce.
+       Gelatine.............................  12  grains.
+
+I emulsified the two together in the usual way, allowed the whole
+to cool, and then poured the thin emulsion into about ten ounces
+of alcohol, stirring the while. As I had anticipated, a flocculent
+precipitate was formed, which settled to the bottom of the vessel in a
+few minutes. This was, in fact, sensitive bromide of silver mixed with
+a very small quantity of gelatine (about five per cent.), and could, I
+found, be treated in the same manner as a bromide precipitate from
+an aqueous solution; it might be washed, either by decantation or by
+filtration, easily dried, and doubtless could, when dry, be kept for an
+indefinite time, and be at any time used by mixing with gelatine and
+water in any proportion thought fit.
+
+I found that a less amount of gelatine than four grains to the ounce was
+sufficient to carry the bromide down, while five grains to the ounce
+carried it down in something which I considered too near an approach to
+a plastic mass.
+
+It will be noticed that in the experiments which I have described the
+emulsion had not been boiled, so that the sensitiveness of the bromide
+was probably not great. As the experiment was done in daylight it was
+of no practical use for making emulsion; but I have since made several
+batches in this manner and have found them most satisfactory.
+
+When sensitiveness is sought by boiling I rind it necessary to add a
+small quantity of gelatine after boiling and before precipitating, as
+that which has been kept for some time at a high temperature seems to
+have lost the viscosity necessary to carry down the silver bromide in
+such a form that it can he easily separated from the alcohol and water.
+
+The practical manner of making an emulsion by this method may be as
+follows. Make up the following mixtures:
+
+  I.
+  Silver nitrate...........................................400 grains.
+  Water..................................................... 3 ounces.
+
+  II.
+
+  Ammonia bromide..........................................240 grains.
+  Gelatine..................................................24 grains
+  Water..................................................... 3 ounces.
+  Hydrochloric acid enough to slightly acidify the solution.
+
+  III.
+  Gelatine................................................. 20 grains.
+  Water....................................................  1/2 ounce.
+  IV.
+
+  Hard gelatine (say Nelson's X opaque,
+  or Mr. A. L. Henderson's)................................240 grains.
+  Soft gelatine (Nelson's No.1)........................... 240 grains.
+  Water.....................................................24 ounces.
+
+Nos. II., III., and IV. are allowed to stand until the gelatine is
+softened. No. I is then warmed in a hock bottle until the gelatine is
+just melted, when No. II. is poured into it, a little at a time, with
+vigorous shaking, until the whole is emulsified. It is then transferred
+to an ordinary jelly can, which is placed in a saucepan half full of
+water over a ring Bunsen burner in the dark room, and boiled for half an
+hour. It is then allowed to cool to about 100 deg. Fahr., when No. III. is
+added. The whole is then allowed to get quite cool, when it is poured,
+with stirring, into about one pint of methylated spirit. If it be wished
+the precipitate may now be filtered out and washed at once like an
+ordinary filtrate, but I prefer to allow it to settle, which it will do
+in about five minutes. The supernatant fluid is then gently poured off.
+
+This fluid will have the appearance of still containing a considerable
+amount of the silver bromide; but if it be kept and filtered it will be
+seen that the quantity is really so small that it may be disregarded. We
+all know what an alarming quantity of silver seems to be going down the
+sink when we wash vessels to which a very small quantity of emulsion is
+adhering. If filtering be resorted to the liquid which comes through
+will be quite clear. This was somewhat unexpected by me, as, if an
+emulsion containing the whole of the gelatine be precipitated into
+alcohol in the usual way, the alcohol becomes milky with a substance
+which could not, I imagine, be filtered from it.
+
+Two or three ounces of methylated spirit are now added to the vessel
+containing the silver bromide, and the latter well mixed with it. This
+makes the precipitate "firmer"--if such an expression be allowable--and
+this time it will sink to the bottom almost immediately after the
+stirring has ceased, and the alcohol may be poured off.
+
+I consider that the bromide in this state is practically free from
+soluble salts, but it may be washed with one or two changes of water if
+desired.
+
+No. IV. is now gently heated till the gelatine is melted and the
+precipitate mixed with it. It must be kept warm for some time, and
+shaken vigorously until all granularity has disappeared, This is, of
+course, ascertained by placing a drop of the emulsion on a piece of
+glass, and examining it. If it be wished to keep the bromide of silver
+for future use it may be placed on a piece of muslin stretched in the
+drying-box, when it will dry in a very short time; and, although I
+cannot speak from experience on this point, it will, I have no doubt,
+keep for an indefinite time so long as light is kept from it.
+
+If it be desired the ammonio-nitrate method may be used instead of the
+boiling one, although in my hands it does not give such sensitiveness.
+If it be desired to use this method, solution Nos. I, II., and IV. are
+made up exactly as for the boiling method, except that No. II. is not
+acidified. Liquid ammonia is then poured with stirring into the silver
+solution, until it blackens and again clears. Emulsification is
+performed exactly as described above, but instead of boiling, the
+emulsion is kept at a temperature of about 100 deg. Fahr. for half an hour,
+when it is poured into the alcohol, no addition of gelatine being
+previously made.
+
+I think I may claim for the method which I have just described that it
+is less troublesome and more certain than either the ordinary washing
+method or the usual one of precipitating with alcohol, while it affords
+an easy method of making sensitive silver bromide in such a form that it
+can be more easily stored and afterwards manipulated than if it were in
+the form of pellicle. The whole of the soluble salts are eliminated,
+and also any gelatine which may have been destroyed in the cooking.
+The amount of alcohol used is comparatively small; in fact, to prepare
+silver bromide for a pint of emulsion very little more than a pint of
+methylated spirit is required. Besides this I do not think that I would
+be wrong in saying that the chance of green fog is reduced to a minimum.
+
+Let me take this opportunity of thanking Captain Abney for his prompt
+reply to my question about the connection between the proportion
+of bromide to gelatine in emulsions, and the density of resulting
+images.--_W. K. Burton, in British Journal of Photography_.
+
+       *       *       *       *       *
+
+[Illustration: Old Wrought Iron Gates, Guildhall.]
+
+       *       *       *       *       *
+
+
+
+
+THE POTTERY AND PORCELAIN INDUSTRIES OF JAPAN.
+
+
+Japanese chronicles claim that the first pottery was made in the year
+660 B.C.; it was not, however, until the Christian era that the art made
+any considerable advances. In the year 1223 A.D., great improvements
+were made in manufacture and decoration of the ware. From that date to
+the sixteenth century the great potteries of Owari, Hizen, Mino, Kioto,
+Kaga, and Satsuma were established. The Rahn-Yaki, or crackled ware, was
+first made at Kioto, at the commencement of the sixteenth century. The
+best old Hizen ware, that which is still the most admired, was made
+at Arita Hizen, in 1580 to 1585; the old Satsuma dates from 1592.
+Consul-General Van Buren states that porcelain clays are found in nearly
+all parts of the country, and the different kinds are usually found
+in close proximity, and close to canals and rivers, which is of
+considerable advantage, as affording a means of transport. In all cases
+every variety of clay used in the manufacture of pottery is found in a
+natural state; there is no necessity to manufacture the quartzose or
+fusible clays as is done in other parts of the world, and which adds
+considerably to the cost of the ware. One of the peculiarities in the
+clay found in Japan is that it contains both the fusible and infusible
+materials in such proportions as to make a light, beautiful,
+translucent, and durable porcelain. At Arita, in Hizen, there is a clay
+found which contains 783/4 per cent, of silica, and l73/4 per cent, of
+alumina; from this clay is made the delicate, translucent eggshell ware,
+without the addition of any other matter. From an adjoining bluff a clay
+is taken which has 50 per cent, of silica, and 38 per cent, of alumina;
+from this the common porcelain is made.
+
+Potter's clay is found in very large quantities in the provinces of
+Yamashiro, Hoki, Turoo Iyo, Hizen, Higo, Owari, Mikaera, Idyn, Musashi,
+and Mino. In the whole of Japan there are 283 localities where the clay
+is deposited; many of these only furnish inferior clays, but they are
+all fitted for use in some of the various kinds of pottery. These clays
+are thoroughly powdered by means of what is called "balance pounders,"
+worked in some localities by water-power, but the work is often done by
+hand. The powder is then dried, and stored on boards or in flat boxes.
+This dough does not go through the process of fermentation. The shaping
+is almost exclusively done on the potter's wheel, which is set on a
+pivot working in a porcelain eye. As a rule, the wheel is turned by the
+potter himself, but in Hizen it is kept in motion by means of a band
+connected with its pivot and another wheel turned by a boy. In making
+dishes of other shape than round, a crude mould is sometimes used. After
+the clay has been shaped on the wheel, it is set away for drying, and
+usually in two or three days it is considered sufficiently dry for
+smoothing, which is done on the wheel with a sharp curved knife. The
+material is now made into "bisque," or biscuit, by a preliminary baking
+in small ovens, when it is ready for painting, if it is to be painted
+on the biscuit; if not, it is ready for the glazing. In either event it
+will then go to the large furnace for the final baking. The kilns for
+this purpose are always built on hill sides, and are joined together,
+increasing in size from the lower to the higher ones, and in number from
+four to twenty five; these kilns are so constructed that the draught is
+from the lowest one, in addition to which each kiln has its own firing
+place. The result of this construction is that the upper ones are by
+far the most heated, and the ware is arranged accordingly; that which
+requires the least baking, in the lower kiln, and that which requires
+the greatest heat, in the upper. These connecting kilns have the merit
+of being heat saving, but they are usually small and badly constructed,
+and the heat in none of them is uniform.
+
+The glaze is made from the silicious clay and potash extracted from wood
+ashes. This potash is not a pure white, and this accounts for the dirty
+color usually to be observed in unpainted Japanese ware. In different
+districts the painting varies. For instance, in Owari, the greater part
+of the ware is painted a cobalt blue--the cobalt ore being found in the
+bluffs near the clay deposits, and is used for painting the cheaper
+wares, and for this purpose German cobalt is also employed. The painting
+with cobalt is generally done on the biscuit before glazing. In several
+districts a very handsome ware is made, and painted on the glaze. For
+this kind of painting the colors are mixed with a silicate of lead
+and potash, and baked the third time in a small furnace at a low
+temperature. The coloring oxides in use are those of copper, cobalt,
+iron, antimony, manganese, and gold. Japanese porcelain painting may be
+divided into two categories, decorative and graphic; the first is used
+to improve the vessel upon which it is placed, and this class includes
+all the ware except that of the province of Kaga, which would come under
+the head of graphic, as it delineates all the trades, occupations,
+sports, customs, and costumes of the people, as well as the scenery,
+flora, and fauna of the country. "Owari ware" is made in the province
+of that name; it is not as translucent, but stronger and more tenacious
+than some of the Hizen manufacture.
+
+The principal potteries are at a village called Seto, twelve miles from
+the sea; in this village there are more than 200 kilns. The ware is
+mostly painted a cobalt blue, and is merely of a decorative kind,
+consisting of branches of trees, grass, flowers, birds, and insects, all
+these being copied by the artist from nature. All the Owari ware is true
+hard porcelain, and is strong and durable. In Hizen, a number of wares
+are manufactured, the best known kind being the "Eurari," which is made
+at Arita, but painted at Eurari. The colors in use are red, blue, green,
+and gold; these are combined in various proportions, but, as a rule, the
+red predominates. Generally the surface of the vessel is divided into
+medallions of figures, which alternately have red, blue, or white
+back-ground, with figures in green or blue and gold.
+
+The egg-shell porcelain sold at Nagasaki is made in this province from
+Arita clay, and this is made from clay with no admixture of fusible
+matter except that contained by the clay naturally. The province of
+Satsuma is noted for crackled ware. It is only within a very few years
+that large vases have been manufactured, and in earlier days the old
+ware was confined to small vessels. The glaze is a silicate of alumina
+and potash, and the best ware has a complete network of the finest
+crackles; the painting is of birds and flowers, and noted for its
+delicate lines of green, red, and gold.
+
+In Kioto, the ware manufactured is very similar to that produced in
+Satsuma, but it is lighter and more porous; the decorations are also
+nearly the same, being of birds and flowers. There is a description of
+ware made in Kioto, called "Eraku," the whole body of which is covered
+with a red oxide of iron, and over this mythical figures of gold are
+traced. That produced in Kagja is _faience_, and in the style of
+painting is unlike any other in Japan, the predominating color being
+a light red, used with green and gold. The designs with which it is
+profusely decorated are trees, grasses, flowers, birds, and figures of
+all classes of people, with their costumes, occupations, and pastimes.
+The "Banko" ware is made at the head of the Owari Bay; it is an unglazed
+stone-ware, very light and durable, made on moulds in irregular shapes,
+and decorated with figures in relief. On the island of Awadji, a
+delicate, creamy, crackled, soft paste porcelain is made. The figures
+used in decoration are birds and flowers, but outlined by heavy, dark
+lines.
+
+Consul Van Buren is of opinion that, at no distant day, Japan will be
+one of the foremost competitors in the pottery markets of the world,
+on account of the great variety and excellence of the clays, their
+proximity to the sea, the cheapness of labor, and the beauty and
+originality of the decorations. Already this important industry has been
+greatly stimulated by the foreign demand, and by the success of
+Japanese exhibitors at the Exhibitions of Vienna, Philadelphia, and
+Paris.--_Journal of the Society of Arts_.
+
+       *       *       *       *       *
+
+Professor Julius E. Hilgard, for twenty years assistant in charge of the
+office, has been placed in temporary charge of the Coast and Geodetic
+Survey. It is understood that he will be appointed superintendent to
+succeed the late Captain Carlile P. Patterson.
+
+       *       *       *       *       *
+
+
+
+
+THE FRENCH CRYSTAL PALACE.
+
+
+The first idea of the French Crystal Palace was suggested by the English
+structure of the same name at Sydenham, about eight miles from London.
+Such a structure, as may be readily conceived, requires a site of vast
+extent, and one that shall be easy of access and possess the most
+agreeable surroundings. To the promoter of the project, those portions
+of the park of St. Cloud in the vicinage of the old chateau appeared to
+combine within themselves all the conditions that were desirable, and
+he, therefore, on the 15th of December, 1879, addressed the Ministers of
+Public Works and of Finances asking for the necessary concessions. The
+extensive specifications have been finally completed and will probably
+be shortly submitted for the approval of the parliament. The moment has
+arrived then for the public press to take cognizance of a project which
+concerns so great interests.
+
+[Illustration: THE FRENCH CRYSTAL PALACE--PARK OF ST CLOUD, PARIS.]
+
+At present we shall say a few words _a propos_ of the engraving we
+present herewith. The French Crystal Palace will consist of one great
+nave, two lateral naves, two surrounding galleries, and a vast rotunda
+behind. The principal entrance, located at the head of the avenue
+leading from the present ruins (which will, ere long, be transformed
+into a most interesting museum), will exhibit a very striking aspect
+with its monumental fountain and the dome which it is proposed to erect
+over the very entrance itself. The whole structure will cover about
+nineteen acres of ground, thus being two and a half times the extent of
+the Palace of Industry in the Champs Elysees. The great nave of honor
+will be nearly 1,650 ft. in length, 78 ft. in width, and 98 ft. in
+height. The dome will measure exactly 328 ft. in height, or 105 ft. more
+than the towers of Notre Dame. The structure, with the exception of
+basement and foundation, will be of glass and iron.
+
+The project which we publish to-day has been studied and gotten up,
+according to the general plans and dimensions suggested by the promoter,
+by Mr. Dumoulin, the architect. We are informed that the builder is to
+be Mr. Alfred Hunnebelle, a contractor well known from the extensive
+works that he has executed, and who is president of the Syndical Chamber
+of Contractors of Paris.
+
+Among the annexes of this palace we may note a "Palace of the Republic,"
+to be built on the ruins and designed for illustrious or distinguished
+visitors, such as the President of the Republic, the Ministers, the
+Municipal Council of Paris, foreign delegates, etc.; a farm house for
+special exhibitions and a field for experiments; galleries, cottages,
+etc.
+
+As for the programme, which embraces six divisions and numerous
+subdivisions, we are unable to give it at present for want of space; we
+need only say that it satisfies perfectly all the conditions of so vast
+an undertaking.
+
+In the hands of the projector, Mr. Nicole, who is well known from his
+long experience in such matters, the exhibition will undoubtedly prove
+a success and be instrumental in adding prosperity to all French
+industries.
+
+       *       *       *       *       *
+
+THE GREAT HEAT OF THE SUN.--Prof. S. P. Langley has made the following
+calculation: A sunbeam one centimeter in section is found in the clear
+sky of the Alleghany Mountains to bring to the earth in one minute
+enough heat to warm one gramme of water by 1 deg. C. It would, therefore,
+if concentrated upon a film of water 1/500th of a millimeter thick,
+1 millimeter wide, and 10 millimeters long, raise it 83 1/3 deg. in one
+second, provided all the heat could be maintained. And since the
+specific heat of platinum is only 0.0032 a strip of platinum of the same
+dimensions would, on a similar supposition, be warmed _in one second_ to
+2,603 deg. C.--a temperature sufficient to melt it!
+
+       *       *       *       *       *
+
+
+
+
+CHATEAU IN THE AEGEAN SEA.
+
+
+From the site of this building, magnificent views are obtained over the
+island-dotted sea and the mainland of Asia Minor: but, "though every
+prospect pleases," it is a land of earthquakes, and unfortunately, the
+works at the chateau have been suspended, owing to the dreadful calamity
+which has recently fallen upon the district. The building is intended
+for the residence of an English lady of exalted rank. It is to be built
+of local white stone, the hall, staircase, etc., being lined and paved
+with marbles. The hall is a large apartment about 25 ft. high, with
+paneled ceiling, having galleries on two sides, giving access to the
+rooms surrounding it on first floor, and to the turret staircase leading
+to roofs, etc. With the exception of sanitary apparatus, painted
+windows, etc. (which will be supplied by English firms), the whole of
+the work will be executed by native labor. The architect is Mr. Edwin T.
+Hall, London.--_Building News_.
+
+[Illustration: SUGGESTIONS IN ARCHITECTURE--A CASTELLATED CHATEAU.]
+
+       *       *       *       *       *
+
+
+
+
+ELECTRIC POWER.
+
+
+Just now nothing save electricity is talked about in scientific circles.
+During the meeting of the British Association the greatest possible
+prominence was given to electrical questions and propositions The
+success of the electric light, the introduction of the Faure battery
+with a great flourish of trumpets, and the magnificent display of
+electrical instruments and machinery at Paris, have all operated to the
+same end. The daily press has taken the subject up, and journals which
+were nothing hitherto if not political, now indulge in magnificent
+rhapsodies concerning the future of electricity. Even eminent engineers,
+carried away by the intoxication of the moment, have not hesitated to
+say that the steam engine is doomed, and that its place will be taken by
+the electricity engine. In the midst of all this noise and clamor and
+blowing of personal trumpets, it is not easy to keep one's head clear,
+and mistakes may be made which will cause disappointment to many and
+retard the progress of electrical science. We confidently expect that
+electricity will prove a potent agent by and by in the hands of the
+speculator for extracting gold from the pockets of the public, and we
+write now to warn our readers in time, and to endeavor to clear the air
+of some of the mists with which it is obscured. There is, no doubt,
+a great future before electricity; but it is equally certain that
+electricity can never do many things which the half informed may be
+readily made to believe it will do. We propose here to say enough
+on this point to enlighten our readers, without troubling them with
+perplexing problems and speculations.
+
+No one at this moment knows what electricity is; but for our present
+purpose we may regard it as a fluid, non-elastic, and without weight,
+and universally diffused through the universe. To judge by recently
+published statements, a large section of the reading public are taught
+that this fluid is a source of power, and that it may be made to do the
+work of coal. This is a delusion. So long as electricity remains in what
+we may call a normal state of repose, it is inert. Before _we can get
+any work out of electricity a somewhat greater amount of work must be
+done upon it_. If this fundamental and most important truth be kept in
+view it will not be easy to make a grave mistake in estimating the value
+of any of the numerous schemes for making electricity do work which will
+ere long be brought before the public. To render our meaning clearer,
+we may explain that in producing the electric light, for instance, a
+certain quantity of electricity passes in through one wire to the lamp,
+and precisely the same quantity passes out through the other wire, and
+on to the earth or return wire completing the circuit. Not only is the
+quantity the same, the velocity is also unchanged. But in going through
+the lamp the current has done something. It has overcome the resistance
+of the carbons, heated them to a dazzling white heat, and so performed
+work. In doing this the current of electricity has lost something. Led
+from the first lamp to a second, it is found powerless--if the first
+lamp be of sufficient size. What is it that the electricity has lost?
+It has parted with what electricians would term "potential," or the
+capacity for performing work. What this is precisely, or in what way the
+presence or absence of potential modifies the nature of the electric
+current, no one knows; but it is known that this potential can only be
+conferred on electricity by doing work on the electricity in the first
+instance. The analogy between electricity and a liquid like water will
+now be recognized. So long as the water is at rest, it is inert. If we
+pump it up to a height, we confer on it the equivalent of potential.
+We can let the water fall into the buckets of an overshot wheel. Its
+velocity leaving the tail race may be identical with that at which it
+left the supply trough to descend on the wheel. Its quantity will be
+the same. It will be in all respects unchanged, just as the current
+of electricity passing through a lamp is unchanged; but it has,
+nevertheless, lost something. It has parted with its potential--capacity
+for doing work--and it becomes once more inert. But the duty which it
+discharged in turning the mill wheel was somewhat less than the precise
+equivalent of the work done in pumping it up to a level with the top of
+the wheel. In the same way the electric current never can do work equal
+in amount to the work done on it in endowing it with potential.
+
+It will thus be seen that electricity can only be used as a means of
+transmitting power from one place to another, or for storing power up
+at one time to be used at a subsequent period; but it cannot be used to
+originate power in the way coal can be used. It possesses no inherent
+potential. It is incapable of performing work unless something is done
+to it first. We have spoken of it as a fluid, but only for the sake of
+illustration. As we have said, no one knows what it is, but the theory
+which bids fair for acceptance is that it is a mode of motion of the
+all-pervading ether. Very curious and instructive experiments are now
+being carried out in Paris by Dr. Bjerkness, of Christiania, in the
+Norwegian section of the electrical exhibition. This gentleman submerges
+thin elastic diaphragms in water, and causes them to vibrate, or rather
+pulsate, by compressed air. He finds that if they pulsate synchronously
+they attract each other. If the pulsations are not simultaneous, the
+disks repel each other. From this and other results he has obtained,
+it may be argued that the ether plays the part of the water in Dr.
+Bjerkness' tank, and that when special forms of vibration are set up
+in bodies they become competent to attract or repel other bodies. This
+being so, it will be seen that the power of attraction or repulsion of
+an electrical body depends in the first instance on the motion set up
+in the body attracted or repulsed, and this motion is, of course, some
+function of the work originally done on the body. We need not pursue
+this argument further. Among the most scientific investigators of the
+day it is admitted that the efficiency of electricity as a doer of work,
+or a producer of action at a distance, must depend for its value on the
+performance of work in some one way or another on the electricity itself
+in the first instance. It may be worth while here to dispel a popular
+delusion. It is held very generally that electricity can be made, as,
+for instance, by the galvanic battery. There is no reason to believe
+anything of the kind; but whether it is or is not true that electricity
+is actually made by the combustion of zinc in a galvanic trough, it is
+quite certain that this electricity, unless it possesses potential, can
+do no work, no matter how great its quantity. Of course, it is to be
+understood that all electric currents possess potential. If they did
+not, their presence would be unknown; but the potential of a current
+is in all cases the result of work done on electricity, either by the
+oxidation of zinc, or in some other way. This is a broad principle, but
+it is strictly consistent in every respect with the truth. Electricity,
+then, is, as we have said, totally different from coal; and it can never
+become a substitute for it alone. Water power, air power, or what we
+may, for want of a better phrase, call chemical power, combined with
+electricity, can be used as a substitute for coal; but electricity
+cannot of itself be employed to do work. It is true, however, that
+electricity, on which work has already been done, may be found in
+nature. Atmospheric electricity, for example, may perhaps yet be
+utilized. It is by no means inconceivable that the electricity contained
+in a thunder cloud might be employed to charge a Faure battery; but up
+to the present no one has contemplated the obtaining of power from the
+clouds, and whether it is or is not practicable to utilize a great
+natural force in this way does not affect our statement. The use of
+electricity must be confined to its power of transmitting or storing up
+energy, and this truth being recognized, it becomes easy to estimate the
+future prospects of electricity at something like their proper value.
+
+It has been proved to a certain extent that electricity can be used to
+transmit power to a distance, and that it can be used to store it up.
+Thus far the man of pure science. The engineer now comes on the stage
+and asks--Can practical difficulties be got over? Can it be made to pay?
+In trying to answer these questions we cannot do better than deal with
+one or two definite proposals which have been recently made. That with
+which we shall first concern ourselves is that trains should be worked
+by Faure batteries instead of by steam. It is suggested that each
+carriage of a train should be provided with a dynamo motor, and that
+batteries enough should be carried by each to drive the wheels, and so
+propel the train. Let us see how such a scheme would comply with working
+conditions. Let us take for example a train of fifteen coaches on the
+Great Northern Railway, running without a stop to Peterborough in one
+hour and forty minutes. The power required would be about 500 horses
+indicated. To supply this for 100 minutes, even on the most absurdly
+favorable hypothesis, no less than 25 tons of Faure batteries would be
+required. Adding to these the weight of the dynamo motors, and that
+unavoidably added to the coaches, it will be seen that a weight equal to
+that of an engine would soon be reached. The only possible saving would
+be some 28 to 30 tons of tender. In return for this all the passengers
+would have to change coaches at Peterborough, as the train could not be
+delayed to replace the expended with fresh batteries. This is out of
+the question. The Faure batteries must all be carried on one vehicle or
+engine, which could be changed for another, like a locomotive. Even then
+no advantage would be gained. As to cost, it is very unlikely that the
+stationary engines which must be provided to drive the dynamo machines
+for charging the batteries would be more economical than locomotive
+engines; and if we allow that the dynamo machine only wasted 10 per
+cent. of the power of the engine, the Faure batteries 10 per cent. of
+the power of the dynamo machines, and the dynamo motors 10 per cent. of
+the power of the batteries--all ridiculously favorable assumptions--yet
+the stationary engines would be handicapped with a difference in net
+efficiency between themselves and the locomotive--admitting the original
+efficiency per pound of coal in both to be the same--of some 27 per
+cent., we think we may relegate this scheme to the realms of oblivion.
+Another idea is that by putting up turbines and dynamo machines the
+steam engine might be superseded by water power. Now it so happens that
+if all the water power of England were quadrupled it would not nearly
+suffice for our wants. It may be found worth while perhaps to construct
+steam engines close to coalpits and send out power from these engines by
+wire; but the question will be asked, Which is the cheaper of the two,
+to send the coal or to send the power? On the answer to this will
+depend the decision of the mill owners. Another favorite scheme is that
+embodied in the Siemens electrical railway. We believe that there is a
+great future in store for electricity as a worker of tramway traffic;
+but the traffic on a great line like the Midland or Great Northern
+Railway could not be carried on by it. As Robert Stephenson said of the
+atmospheric system, it is not flexible enough. The working of points
+and crossings, and the shunting of trains and wagons, would present
+unsurmountable difficulties. We have cited proposals enough, we think,
+to illustrate our meaning. Sir William Armstrong, Sir Frederick
+Bramwell, Dr. Siemens, Sir W. Thomson, and many others may be excused if
+they are a little enthusiastic. They are just now overjoyed with success
+attained; but when the time comes for sober reflection they will, no
+doubt, see good reason to moderate their views. No one can say, of
+course, what further discoveries may bring to light; but recent speakers
+and writers have found in what is known already, materials for sketching
+out a romance of electricity. It is but romancing to assert that the end
+of the steam engine is at hand. Wonderful and mystical as electricity
+is, there are some very hard and dry facts about it, and these facts are
+all opposed to the theory that it can become man's servant of all work.
+Ariel-like, electricity may put a girdle round the earth in forty
+minutes; but it shows no great aptitude for superseding the useful old
+giant steam, who has toiled for the world so long and to such good
+purpose--_The Engineer_.
+
+       *       *       *       *       *
+
+
+
+
+ON A METHOD OF OBTAINING AND MEASURING VERY HIGH VACUA WITH A MODIFIED
+FORM OF SPRENGEL-PUMP.
+
+By Ogden N. Rood, Professor of Physics in Columbia College.
+
+
+In the July number of this Journal for 1880, I gave a short account of
+certain changes in the Sprengel-pump by means of which far better vacua
+could be obtained than had been previously possible. For example, the
+highest vacuum at that time known had been reached by Mr. Crookes, and
+was about 1/17,000,000, while with my arrangement vacua of 1/100,000,000
+were easily reached. In a notice that appeared in _Nature_ for August,
+1880, p. 375, it was stated that my improvements were not new, but had
+already been made in England four years previously. I have been unable
+to obtain a printed account of the English improvements, and am willing
+to assume that they are identical with my own; but on the other hand,
+as for four years no particular result seems to have followed their
+introduction in England, I am reluctantly forced to the conclusion that
+their inventor and his customers, for that period of time, have remained
+quite in ignorance of the proper mode of utilizing them. Since then I
+have pushed the matter still farther, and have succeeded in obtaining
+with my apparatus vacua as high as 1/390,000,000 without finding
+that the limit of its action had been reached. The pump is simple in
+construction, inexpensive, and, as I have proved by a large number of
+experiments, certain in action and easy of use; stopcocks and grease are
+dispensed with, and when the presence of a stopcock is really desirable
+its place is supplied by a movable column of mercury.
+
+_Reservoir_.--An ordinary inverted bell-glass with a diameter of 100 mm.
+and a total height of 205 mm. forms the reservoir; its mouth is closed
+by a well-fitting cork through which passes the glass tube that forms
+one termination of the pump. The cork around tube and up to the edge of
+the former is painted with a flexible cement. The tube projects 40 mm.
+into the mercury and passes through a little watch-glass-shaped piece of
+sheet-iron, W, figure 1, which prevents the small air bubbles that creep
+upward along the tube from reaching its open end; the little cup is
+firmly cemented in its place. The flow of the mercury is regulated
+by the steel rod and cylinder, CR, Figure 1. The bottom of the steel
+cylinder is filled out with a circular piece of pure India-rubber,
+properly cemented; this soon fits itself to the use required and answers
+admirably. The pressure of the cylinder on the end of the tube is
+regulated by the lever, S, Figure 1; this is attached to a circular
+board which again is firmly fastened over the open end of the
+bell-glass. It will be noticed that on turning the milled head, S, the
+motion of the steel cylinder is not directly vertical, but that it tends
+to describe a circle with c as a center; the necessary play of the
+cylinder is, however, so small, that practically the experimenter does
+not become aware of this theoretical defect, so that the arrangement
+really gives entire satisfaction, and after it has been in use for a few
+days accurately controls the flow of the mercury. The glass cylinder is
+held in position, but not supported, by two wooden _adjustable_ clamps,
+_a a_, Figure 2. The weight of the cylinder and mercury is supported by
+a shelf, S, Figure 2, on which rests the cork of the cylinder; in this
+way all danger of a very disagreeable accident is avoided.
+
+[Illustration: MODIFIED FORM OF SPRENGEL PUMP.]
+
+_Vacuum-bulb_.--Leaving the reservoir, the mercury enters the
+vacuum-bulb, B, Figure 2, where it parts with most of its air and
+moisture; this bulb also serves to catch the air that creeps into the
+pump from the reservoir, even when there is no flow of mercury; its
+diameter is 27 mm. The shape and inclination of the tube attached to
+this bulb is by no means a matter of indifference; accordingly Figure
+3 is a separate drawing of it; the tube should be so bent that a
+horizontal line drawn from the proper level of the mercury in the bulb
+passes through the point, _o_, where the drops of mercury break off. The
+length of the tube, EC, should be 150 mm., that of the tube, ED, 45 mm.;
+the bore of this tube is about the same as that of the fall-tube.
+
+_Fall-tube and bends_.--The bore of the fall-tube in the pump now used
+by me is 1.78 mm.; its length above the bends (U, Figure 2) is 310 mm.;
+below the bends the length is 815 mm. The bends constitute a fluid valve
+that prevents the air from returning into the pump; beside this, the
+play of the mercury in them greatly facilitates the passage of the
+air downward. The top of the mercury column representing the existing
+barometric pressure should be about 25 mm. below the bends when the pump
+is in action. This is easily regulated by an adjustable shelf, which is
+also employed to fill the bends with mercury when a measurement is taken
+or when the pump is at rest. On the shelf is a tube, 160 mm. high and 20
+mm. in diameter, into which the end of the fall-tube dips; its side has
+a circular perforation into which fits a small cork with a little tube
+bent at right angles. With the hard end of a file and a few drops of
+turpentine the perforation can be easily made and shaped in a few
+minutes. By revolving the little bent tube through 180 deg. the flow of the
+mercury can be temporarily suspended when it is desirable to change the
+vessel that catches it.
+
+_Gauge_.--For the purpose of measuring the vacua I have used an
+arrangement similar to McLeod's gauge, Figure 4; it has, however, some
+peculiarities. The tube destined to contain the compressed air has a
+diameter of 1.35 mm. as ascertained by a compound microscope; it is not
+fused at its upper extremity, but closed by a fine glass rod that fits
+into it as accurately as may be, the end of the rod being ground flat
+and true. This rod is introduced into the tube, and while the latter
+is gently heated a very small portion of the cement described below is
+allowed to enter by capillary attraction, but not to extend beyond the
+end of the rod, the operation being watched by a lens. The rod is
+used for the purpose of obtaining the compressed air in the form of a
+cylinder, and also to allow cleansing of the tube when necessary. The
+capacity of the gauge-sphere was obtained by filling it with mercury;
+its external diameter was sixty millimeters; for measuring very high
+vacua this is somewhat small and makes the probable errors rather
+large; I would advise the use of a gauge-sphere of about twice as great
+capacity. The tube, CB, Figure 4, has the same bore as the measuring
+tube in order to avoid corrections for capillarity. The tube of the
+gauge, CD, is not connected with an India-rubber tube, as is usual,
+but dips into mercury contained in a cylinder 340 mm. high, 58 mm. in
+diameter, which can be raised and lowered at pleasure. This is best
+accomplished by the use of a set of boxes of various thicknesses, made
+for the purpose and supplemented by several sheets of cardboard and even
+of writing-paper. These have been found to answer well and enable the
+experimenter to graduate with a nicety the pressure to which the gas is
+exposed during measurement. By employing a cylinder filled with mercury
+instead of the usual caoutchouc tubing small bubbles of air are
+prevented from entering the gauge along with the mercury. An adjustable
+brace or support is used which prevents accident to the cylinder when
+the pump is inclined for the purpose of pumping out the vacuum-bulb. The
+maximum pressure that can be employed in the gauge used by me is 100 mm.
+
+All the tubing of the pump is supported at a distance of about 55 mm.
+from the wood-work; this is effected by the use of simple adjustable
+supports and adjustable clamps; the latter have proved a great
+convenience. The object is to gain the ability to heat with a Bunsen
+burner all parts of the pump without burning the wood-work. Where glass
+and wood necessarily come in contact the wood is protected by metal or
+simply painted with a saturated solution of alum. The glass portions
+of the pump I have contrived to anneal completely by the simple means
+mentioned below. If the glass is not annealed it is certain to crack
+when subjected to heat, thus causing vexation and loss of time. The
+mercury was purified by the same method that was used by W. Siemens
+(Pogg. Annalen, vol. ex., p. 20), that is, by a little strong sulphuric
+acid to which a few drops of nitric acid had been added; it was dried by
+pouring it repeatedly from one hot dry vessel to another, by filtering
+it while quite warm, the drying being completed finally by the action of
+the pump itself. All the measurements were made by a fine cathetometer
+which was constructed for me by William Grunow; see this Journal, Jan.,
+1874, p. 23. It was provided with a well-corrected object-glass having a
+focal length of 200 mm. and as used by me gave a magnifying power of 16
+diameters.
+
+_Manipulation_.--The necessary connections are effected with a cement
+made by melting Burgundy pitch with three or four per cent of gutta
+percha. It is indispensable that the cement when cold should be so hard
+as completely to resist taking any impression from the finger nail,
+otherwise it is certain to yield gradually and finally to give rise to
+leaks. The connecting tubes are selected so as to fit as closely as
+possible, and after being put into position are heated to the proper
+amount, when the edges are touched with a fragment of cold cement which
+enters by capillary attraction and forms a transparent joint that can
+from time to time be examined with a lens for the colors of thin plates,
+which always precede a leak. Joints of this kind have been in use by me
+for two months at a time without showing a trace of leakage, and the
+evidence gathered in another series of unfinished experiments goes to
+show that no appreciable amount of vapor is furnished by the resinous
+compound, which, I may add, is never used until it has been repeatedly
+melted. As drying material I prefer caustic potash that has been in
+fusion just before its introduction into the drying tube; during the
+process of exhaustion it can from time to time be heated nearly to the
+melting point: if actually fused in the drying tube the latter almost
+invariably cracks. The pump in the first instance is to be inclined at
+an angle of about 10 degrees, the tube of the gauge being supported by
+a semicircular piece of thick pasteboard fitted with two corks into the
+top of the cylinder. This seemingly awkward proceeding has in no case
+been attended with the slightest accident, and owing to the presence of
+the four leveling-screws, the pump when righted returns, as shown by the
+telescope of the cathetometer, almost exactly to its original place. In
+the inclined position the exhaustion of the vacuum bulb is accomplished
+along with that of the rest of the pump. The exhaustion of the
+vacuum-bulb when once effected can be preserved to a great extent for
+use in future work, merely by allowing mercury from the reservoir to
+flow in a rapid stream at the time that air is allowed to re-enter the
+pump. During the first process of exhaustion the tube of the gauge is
+kept hot by moving to and fro a Bunsen burner, and is in this way
+freed from those portions of air and moisture that are not too firmly
+attached. After a time the vacuum-bulb ceases to deliver bubbles of
+air; it and the attached tube are now to be heated with a moving Bunsen
+burner, when it will be found to furnish for 15 or 20 minutes a large
+quantity of bubbles mainly of vapor of water. After then production
+ceases the pump is righted and the exhaustion carried farther. In spite
+of a couple of careful experiments with the cathetometer I have not
+succeeded in measuring the vacuum in the vacuum bulb, but judge from
+indications, that is about as high as that obtained in an ordinary
+Geissler pump. Meanwhile the various parts of the pump can be heated
+with a moving Bunsen burner to detach air and moisture, the cement being
+protected by wet lamp-wicking. In one experiment I measured the amount
+of air that was detached from the walls of the pump by heating them for
+ten minutes somewhat above l00 deg. C., and found that it was 1/1,000,000
+of the air originally present. I have also noticed that a still larger
+amount of air is detached by electric discharges. This coincides with an
+observation of E. Bessel-Hagen in his interesting article on a new form
+of Toepler's mercury-pump (Annalen der Physik und Chemie, 1881, vol.
+xii.). Even when potash is used a small amount of moisture always
+collects in the bends of the fall tube; this is readily removed by a
+Bunsen burner; the tension of the vapor being greatly increased, it
+passes far down the fall-tube in large bubbles and is condensed. Without
+this precaution I have found it impossible to obtain a vacuum higher
+than 1/25,000,000; in point of fact the bends should always be heated
+when a high exhaustion is undertaken even if the pump has been standing
+well exhausted for a week; the heat should of course never be applied at
+a late stage of the exhaustion. Conversely, I have often by the aid of
+heat completely and quickly removed quite large quantities of the vapor
+of water that had been purposely introduced. The exhaustion of the
+vacuum-bulb is of course somewhat injured by the act of using the pump
+and also by standing for several days, so that it has been usual with me
+before undertaking a high exhaustion to incline the pump and re-exhaust
+for 20 minutes; I have, however, obtained very high vacua without using
+this precaution.
+
+During the process of exhaustion not more than one-half of the mercury
+in the reservoir is allowed to run out, other wise when it is returned
+bubbles of air are apt to find their way into the vacuum-bulb. In order
+to secure its quiet entrance it is poured into a silk bag provided with
+several holes. When the reservoir is first filled its walls for a day
+or two appear to furnish air that enters the vacuum-bulb; this action,
+however, soon sinks to a minimum and then the leakage remains quite
+constant for months together.
+
+_Measurement of the vacuum_.--The cylinder into which the gauge-tube
+dips is first elevated by a box sufficiently thick merely to close the
+gauge, afterwards boxes are placed under it sufficient to elevate the
+mercury to the base of the measuring tube; when the mercury has reached
+this point, thin boards and card-boards are added till a suitable
+pressure is obtained. The length of the inclosed cylinder of air is
+then measured with the cathetometer, also the height of the mercurial
+"meniscus," and the difference of the heights of the mercurial columns
+in A and B, figure 4. To obtain a second measure an assistant removes
+some of the boxes and the cylinder is lowered by hand three or four
+centimeters and then replaced in its original position. In measuring
+really high vacua, it is well to begin with this process of lowering and
+raising the cylinder, and to repeat it five or six times before taking
+readings. It seems as though the mercury in the tube, B, supplies to the
+glass a coating of air that allows it to move more freely; at all events
+it is certain that ordinarily the readings of B become regular, only
+after the mercury has been allowed to play up and down the tube a number
+of times. This applies particularly to vacua as high 1/50,000,000 and to
+pressures of five millimeters and under. It is advantageous in making
+measurements to employ large pressures and small volumes; the correct
+working of the gauge can from time to time be tested by varying the
+relations of these to each other. This I did quite elaborately, and
+proved that such constant errors as exist are small compared with
+inevitable accidental errors, as, for example, that there was no
+measurable correction for capillarity, that the calculated volume of the
+"meniscus" was correct, etc. It is essential in making a measurement
+that the temperature of the room should change as little as possible,
+and that the temperature of the mercury in the cylinder should be at
+least nearly that of the air near the gauge-sphere. The computation is
+made as follows
+
+  n = height of the cylinder inclosing the air;
+  c = a factor which, multiplied by n, converts it into cubic
+                millimeters;
+  S = cubic contents of the meniscus;
+  d = difference of level between A and B, fig. 4;
+    = the pressure the air is under;
+  N = the cubic contents of the gauge in millimeters;
+  x = a fraction expressing the degree of exhaustion obtained; then
+
+          x=1/([N (760/d)]/[nc - S])
+
+It will be noticed that the measurements are independent of the actual
+height of the barometer, and if several readings are taken continuously,
+the result will not be sensibly affected by a simultaneous change of the
+barometer. Almost all the readings were taken at a temperature of about
+20 deg. C., and in the present state of the work corrections for temperature
+may be considered a superfluous refinement.
+
+_Gauge correction_.--It is necessary to apply to the results thus
+obtained a correction which becomes very important when high vacua are
+measured. It was found in an early stage of the experiments that the
+mercury, in the act of entering the highly exhausted gauge, gave out
+invariably a certain amount of air which of course was measured along
+with the residuum that properly belonged there; hence to obtain the true
+vacuum it is necessary to subtract the volume of this air from nc. By a
+series of experiments I ascertained that the amount of air introduced by
+the mercury in the acts of entering and leaving the gauge was sensibly
+constant for six of these single operations (or for three of these
+double operations), when they followed each other immediately. The
+correction accordingly is made as follows: the vacuum is first measured
+as described above, then by withdrawing all the boxes except the lowest,
+the mercury is allowed to fall so as nearly to empty the gauge; it is
+then made again to fill the gauge, and these operations are repeated
+until they amount in all to six; finally the volume and pressure are a
+second time measured. Assuming the pressure to remain constant, or that
+the volumes are reduced to the same pressure,
+
+  v = the original volume;  v' = the final volume;
+  V' = volume of air introduced by the first entry of the mercury;
+  V = corrected volume; then
+
+  V' = (v'-v)/6
+  V = v - [(v'-v)/6]
+
+It will be noticed that it is assumed in this formula that the same
+amount of air is introduced into the gauge in the acts of entry and
+exit; in the act of entering in point of fact more fresh mercury is
+exposed to the action of the vacuum than in the act exit, which might
+possibly make the true gauge-correction rather larger than that given by
+the formula. It has been found that when the pump is in constant use the
+gauge-correction gradually diminishes from day to day; in other words,
+the air is gradually pumped out of the gauge-mercury. Thus on December
+21, the amount of air entering with the mercury corresponded to an
+exhaustion of
+
+  1/27,308,805 .......Dec. 21.
+
+  1/38,806,688 ...... Dec. 29.
+
+  1/78,125,000 .......Jan. 15.
+
+  1/83,333,333 .......Jan. 23
+
+  1/128,834,063 ......Feb. 1.
+
+  1/226,757,400 ..... Feb. 9.
+
+  1/232,828,800 ..... Feb. 19.
+
+  1/388,200,000 ......March 7.
+
+That this diminution is not due to the air being gradually withdrawn
+from the walls of the gauge or from the gauge-tube, is shown by the fact
+that during its progress the pump was several times taken to pieces, and
+the portions in question exposed to the atmosphere without affecting
+the nature or extent of the change that was going on. I also made one
+experiment which proves that the gauge-correction does not increase
+sensibly, when the exhausted pump and gauge are allowed to stand unused
+for twenty days.
+
+_Rate of the pump's work_.--It is quite important to know the rate of
+the pump at different degrees of exhaustion, for the purpose of enabling
+the experimenter to produce a definite exhaustion with facility; also if
+its maximum rate is known and the minimum rate of leakage, it becomes
+possible to calculate the highest vacuum attainable with the instrument.
+Examples are given in the tables below; the total capacity was about
+100,000 cubic mm.
+
+  Time.         Exhaustion.         Ratio.
+
+                1/78,511
+  10 minutes              }........ 1:1/3.53
+                1/276,980
+  10 minutes              }........ 1:1/6.10
+               1/1,687,140
+  10 minutes              }........ 1:1/4.15
+               1/7,002,000
+
+Upon another occasion the following rates and exhaustions were obtained:
+
+  Time.         Exhaustion.         Rate.
+
+               1/7,812,500
+  10 minutes              }........ 1:1/3.18
+              1/24,875,620
+  10 minutes              }........ 1:1/2.69
+              1/67,024,090
+  10 minutes              }........ 1:1/1.22
+              1/81,760,810
+  10 minutes              }........ 1:1.67
+             1/136,986,300
+  10 minutes              }........ 1:1.23
+             1/170,648,500
+
+The _irregular_ variations in the rates are due to the mode in which the
+flow of the mercury was in each case regulated.
+
+_Leakage_.--We come now to one of the most important elements in the
+production of high vacua. After the air is detached from the walls of
+the pump the leakage becomes and remains nearly constant. I give below a
+table of leakages, the pump being in each case in a condition suitable
+for the production of a very high vacuum:
+
+  Duration of the                           Leakage per hour in
+     experiment                               cubic mm., press.,
+                                                 760 mm.
+
+      181/2 hours............................ 0.000853
+      27  hours............................ 0.001565
+      261/2 hours.............................0.000791
+      20  hours.............................0.000842
+      19  hours.............................0.000951
+      19  hours.............................0.001857
+       7  days..............................0.001700
+       7  days..............................0.001574
+
+                Average.................... 0.001266
+
+I endeavored to locate this leakage, and proved that one-quarter of
+it is due to air that enters the gauge from the top of its column of
+mercury, thus:
+
+  Duration of the                         Gauge-leakage per hour
+    experiment.                            in cubic mm., press.
+                                                  760 mm.
+
+    18 hours.................................0.0002299
+     7 days..................................0.0004093
+     7 days..................................0.0003464
+
+               Average.......................0.0003285
+
+This renders it very probable that the remaining three quarters are due
+to air given off from the mercury at B, Fig. 4, from that in the bends
+and at the entrance of the fall-tube, _o_, Fig. 3.
+
+Further on some evidence will be given that renders it probable that the
+leakage of the pump when in action is about four times as great as the
+total leakage in a state of rest.
+
+The gauge, when arranged for measurement of gauge-leakage, really
+constitutes a barometer, and a calculation shows that the leakage would
+amount to 2.877 cubic millimeters per year, press. 760 mm. If this air
+were contained in a cylinder 90 mm. long and 15 mm. in diameter it would
+exert a pressure of 0.14 mm. To this I may add that in one experiment
+I allowed the gauge for seven days to remain completely filled with
+mercury and then measured the leakage into it. This was such as would
+in a year amount to 0.488 cubic millimeter, press. 760 mm., and in a
+cylinder of the above dimensions would exert a pressure of 0.0233 mm.
+
+_Reliability of the results: highest vacuum._
+
+The following are samples of the results obtained. In one case sixteen
+readings were taken in groups of four with the following result:
+
+        Exhaustion.
+       1 / 74,219,139
+       1 / 78,533,454
+       1 / 79,017,272
+       1 / 68,503,182
+  Mean 1 / 74,853,449
+
+Calculating the probable error of the mean with reference to the above
+four results it is found to be 2.28 per cent of the quantity involved.
+
+A higher vacuum measured in the same way gave the following results:
+
+  1 / 146,198,800
+  1 / 175,131,300
+  1 / 204,081,600
+  1 / 201,207,200
+
+The mean is 1 / 178,411,934, with a probable error of 5.42 per cent of
+the quantity involved. I give now an extreme case; only five single
+readings were taken; these corresponded to the following exhaustions:
+
+  1 / 379,219,500
+  1 / 371,057,265
+  1 / 250,941,040
+  1 / 424,088,232
+  1 / 691,082,540
+
+The mean value is 1 / 381,100,000, with a probable error of 10.36 per
+cent of the quantity involved. Upon other occasions I have obtained
+exhaustions of 1 / 373,134,000 and 1 / 388,200,000. Of course in these
+cases a gauge-correction was applied; the highest vacuum that I have
+ever obtained irrespective of a gauge-correction was 1 / 190,392,150. In
+these cases and in general, potash was employed as the drying material;
+I have found it practical, however, to attain vacua as high as 1 /
+50,000,000 in the total absence of all such substances. The vapor of
+water which collects in bends must be removed from time to time with a
+Bunsen burner while the pump is in action.
+
+It is evident that the final condition of the pump is reached when
+as much air leaks in per unit of time as can be removed in the same
+interval. The total average leakage per ten minutes in the pump used by
+me, when at rest, was 0.000211 cubic millimeter at press. 760 mm. Let
+us assume that the leakage when the pump is in action is four times
+as great as when at rest; then in each ten minutes 0.000844 cubic
+millimeter press., 760 mm., would enter; this corresponds in the pump
+used by me to an exhaustion of 1 / 124,000,000; if the rate of the pump
+is such as to remove one-half of the air present in ten minutes, then
+the highest attainable exhaustion would be 1 / 248,000,000. In the same
+way it may be shown that if six minutes are required for the removal of
+half the air the highest vacuum would be 1 / 413,000,000 nearly, and
+rates even higher than this have been observed in my experiments. An
+arrangement of the vacuum-bulb whereby the entering drops of mercury
+would be exposed to the vacuum in an isolated condition for a somewhat
+longer time would doubtless enable the experimenter to obtain
+considerably higher vacua than those above given.
+
+_Exhaustion obtained with a plain Sprengel Pump._--I made a series of
+experiments with a plain Sprengel pump without stopcocks, and arranged,
+as far as possible, like the instrument just described. The leakage per
+hour was as follows:
+
+  Duration of the             Leakage per hour in
+    experiment.               cubic mm. at press.
+                                    760 mm.
+
+  22 hours                          0.04563
+   2 days                           0.04520
+   2 days                           0.09210
+   4 days                           0.06428
+                                    -------
+            Mean                    0.06180
+
+Using the same reasoning as above we obtain the following table
+
+  Time necessary for removal     Greatest attainable
+     of half the air.                exhaustion.
+
+    10 minutes                     1 / 5,000,000
+    7.5 minutes                    1 / 7,000,000
+    6.6 minutes                    1 / 12,000,000
+
+In point of fact the highest exhaustion I ever obtained with this pump
+was 1 / 5,000,000; from which I infer that the leakage during action
+is considerably greater than four times that of the pump at rest. The
+general run of the experiments tends to show that the leakage of a plain
+Sprengel pump, without stopcocks or grease, is, when in action, about 80
+times as great as in the form used by me.
+
+_Note on annealing glass tubes._--It is quite necessary to anneal all
+those parts of the pump that are to be exposed to heat, otherwise they
+soon crack. I found by inclosing the glass in heavy iron tubes and
+exposing it for five hours to a temperature somewhat above that of
+melting zinc, and then allowing an hour or two for the cooling process,
+that the strong polarization figure which it displays in a polariscope
+was completely removed, and hence the glass annealed. A common
+gas-combustion furnace was used, the bends, etc, being suitably inclosed
+in heavy metal and heated over a common ten-fold Bunsen burner. Thus far
+no accident has happened to the annealed glass, even when cold drops of
+mercury struck in rapid succession on portions heated considerably above
+100 deg. C.
+
+I wish, in conclusion, to express my thanks to my assistant, Dr.
+Ihlseng, for the labor he has expended in making the large number of
+computations necessarily involved in work of this kind.--_Amer. Jour. of
+Science._
+
+       *       *       *       *       *
+
+
+
+
+CRYSTALLIZATION TABLE.
+
+
+The following table, prepared by E. Finot and Arm. Bertrand for the
+_Jour. de Ph. et de Chim._, shows the point at which the evaporation of
+certain solutions is to be interrupted in order to procure a good crop
+of crystals on cooling. The density is according to Baume's scale, the
+solution warm:
+
+  Aluminum sulphate       25 | Nickel acetate             30
+  Alum (amm. or pot.)     20 |   "    ammon. sulphate     18
+  Ammonium acetate        14 |   "    chloride            50
+    "      arsenate        5 |   "    sulphate            40
+    "      benzoate        5 | Oxalic acid                12
+    "      bichromate     28 | Potass. and sod. tartrate  36
+    "      bromide        30 | Potassium arsenate         36
+    "      chloride       12 |   "       benzoate          2
+    "      nitrate        29 |   "       bisulphate       35
+    "      oxalate         5 |   "       bromide          40
+    "      phosphate      35 |   "       chlorate         22
+    "      sulphate       28 |   "       chloride         25
+    "      sulphocyanide  18 |   "       chromate         38
+    "      tartrate       25 |   "       citrate          36
+  Barium ethylsulphate    43 |   "       ferrocyanide     38
+    "    formate          32 |   "       iodide           17
+    "    hyposulphite     24 |   "       nitrate          28
+    "    nitrate          18 |   "       oxalate          30
+    "    oxide            12 |   "       permanganate     25
+  Bismuth nitrate         70 |   "       sulphate         15
+  Boric acid               6 |   "       sulphite         25
+  Cadmium bromide         65 |   "       sulphocyanide    35
+  Calcium chloride        40 |   "       tartrate         48
+    "     ethylsulphate   36 | Soda                       28
+    "     lactate          8 | Sodium acetate             22
+    "     nitrate         55 |   "    ammon. phosp.       17
+  Cobalt chloride         41 |   "    arsenate            36
+    "    nitrate          50 |   "    borate              24
+    "    sulphate         40 |   "    bromide             55
+  Copper acetate           5 |   "    chlorate            43
+    "    ammon. sulph.    35 |   "    chromate            45
+    "    chloride         45 |   "    citrate             36
+    "    nitrate          55 |   "    ethylsulphate       37
+    "    sulphate         30 |   "    hyposulphite        24
+  Iron-ammon. oxalate     30 |   "    nitrate             40
+    " ammon. sulphate     31 |   "    phosphate           20
+    " sulphate            31 |   "    pyrophosphate       18
+    " tartrate            40 |   "    sulphate            30
+  Lead acetate            42 |   "    tungstate           45
+    " nitrate             50 | Stroutium bromide          50
+  Magnesium chloride      35 |   "       chlorate         65
+    "       lactate        6 |   "       chloride         34
+    "       nitrate       45 | Tin choride (stannous)     75
+    "       sulphate      40 |
+  Manganese chloride      47 | Zinc acetate               20
+    "       lactate        8 |   "  ammon. chloride       43
+    "       sulphate      44 |   "  nitrate               55
+  Mercury cyanide         20 |   "  sulphate              45
+
+       *       *       *       *       *
+
+
+
+
+THE PRINCIPLES OF HOP-ANALYSIS.
+
+By Dr. G. O. CECH
+
+[Footnote: 'Zeitschrift fur Analyt. Chemie,' 1881.]
+
+
+Hop flowers contain a great variety of different substances susceptible
+of extraction with ether, alcohol, and water, and distinguishable from
+one another by tests of a more or less complex character. The substances
+are: Ethereal oil, chlorophyl, hop tannin, phlobaphen, a wax-like
+substance, the sulphate, ammoniate, phosphate, citrate and malates of
+potash, arabine, a crystallized white and an amorphous brown resin, and
+a bitter principle. That the characteristic action of the hops is due to
+such of these constituents only as are of an organic nature is easy to
+understand; but up to the present we are in ignorance whether it is upon
+the oil, the wax, the resin, the tannin, the phlobaphen, or the bitter
+principle individually, or upon them all collectively, that the effect
+of the hops in brewing depends.
+
+It is the rule to judge the strength and goodness of hops by the amount
+of farina--the so-called lupuline; and as this contains the major
+portion of the active constituents of the hop, there is no doubt that
+approximately the amount of lupuline is a useful quantitative test. But
+here we are confronted by the question whether the lupuline is to be
+regarded as containing _all_ that is of any value in the hops and the
+leaves, the organic principles in which pass undetected under such a
+test, as supererogatory for brewers' purposes? Practical experience
+negatives any such conclusion. Consequently, we are justified in
+assuming that the concurrent development and the presence of the several
+organic principles--the oil, the wax, the bitter, the tannin, the
+phlobaphen, in the choicer sorts--are subject, within certain limits, to
+variations depending on skilled culture and careful drying, and that the
+aggregate of these principles has a certain attainable maximum in
+the finer sorts, under the most favorable conditions of culture, and
+another, lower maximum in less perfectly cultivated and wild sorts. The
+difference in the proportion of active organic substance in each sort
+must be determined by analysis. There then remains to be discovered
+which of the aforesaid substances plays the leading role in brewing, and
+also whether the presence of chlorophyl and inorganic salts in the hop
+extract influences or alters the results.
+
+That in brewing hops cannot be replaced by lupuline alone, even when the
+latter is employed in relatively large quantities is well known, as also
+that a considerable portion of the bitter principle of the hop is found
+in the floral leaves. Neither can the lupuline be regarded as the only
+active beer agent, as both the hop-tannin and the hop-resin serve to
+precipitate the albuminous matter, and clarify and preserve the beer.
+
+Both chemists and brewers would gladly welcome some method of testing
+hops, which should be expeditious, and afford reliable results in
+practical hands. To accomplish this account must be taken of all the
+active organic constituents of the hops, which can be extracted either
+with ether, alcohol, or water containing soda (for the conversion of the
+hop tannin in phlobaphen).[1] It should further be ascertained whether
+the chlorophyl percentage in the hop bells, new and old, is or is not
+the same in cultivated and in wild hops, and whether the aggregate
+percentages of organic and constituent observe the same limits.
+
+[Footnote 1: See C. Etti, in "Dingler's Polytech. Journ.," 1878, p.
+354.]
+
+As wild hops nowadays are frequently introduced in brewing, the
+proportion of chlorophyl and organic and inorganic constituents in them
+should be compared with those of cultivated sorts, taking the best
+Bavarian or Bohemian hops as the standard of measurement. The chlorophyl
+is of minor importance, as it has little effect on the general results.
+
+By a series of comparative analysis of cultivated and wild hops, in
+which I would lay especial stress on parity of conditions in regard
+of age and vegetation, the extreme limits of variation of which their
+active organic principles are susceptible could be determined.
+
+There is every reason to suppose that the chlorophyl and inorganic
+constituents do not differ materially in the most widely different sorts
+of hops. The more important differences lie in the proportions of hop
+resin and tannin. When this is decided, the proportion of tannin or
+phlobaphen in the hop extract or the beer can be determined by analysis
+in the ordinary way. But whenever some quick and sure hop test shall
+have been found, _appearance and aroma_ will still be most important
+factors in any estimate of the value of hops. Here a question arises as
+to whether hops from a warm or even a steppe climate, like that of
+South Russia, contain the same proportion of ethereal oil--that is, of
+aroma--as those from a cooler climate, like Bavaria and Bohemia, or
+like certain other fruit species of southern growth, they are early
+in maturing, prolific, large in size, and abounding in farina, but
+_deficient in aroma_.
+
+The bearings of certain experimental data on this point I reserve for
+consideration upon a future occasion.--_The Analyst_.
+
+       *       *       *       *       *
+
+
+
+
+WATER GAS.
+
+A DESCRIPTION OF APPARATUS FOR PRODUCING CHEAP GAS, AND SOME NOTES ON
+THE ECONOMICAL EFFECT OF USING SUCH GAS WITH GAS MOTORS, ETC.
+
+[Footnote: Abstract of paper read in Section G. British Association,
+York]
+
+By MR. J. EMERSON DOWSON, C.E., of London.
+
+
+In many countries and for many years past, inventors have sought
+some cheap and easy means of decomposing steam in the presence of
+incandescent carbon in order to produce a cheap heating gas; and working
+with the same object the writer has devised an apparatus which has been
+fitted up in the garden of the Industrial Exhibition, and is there
+making gas for a 31/2 horse power (nominal) Otto gas engine. The retort or
+generator consists of a vertical cylindrical iron casing which incloses
+a thick lining of ganister to prevent loss of heat and oxidation of the
+metal, and at the bottom of this cylinder is a grate on which a fire is
+built up. Under the grate is a closed chamber, and a jet of superheated
+steam plays into this and carries with it by induction a continuous
+current of air. The pressure of the steam forces the mixture of steam
+and air upward through the fire, so that the combustion of the fuel is
+maintained while a continuous current of steam is decomposed, and in
+this way the working of the generator is constant, and the gas is
+produced without fluctuations in quality. The well-known reactions
+occur, the steam is decomposed, and the oxygen from the steam and air
+combines with the carbon of the fuel to form carbon dioxide (CO_2),
+which is reduced to the monoxide (CO) on ascending the fuel column.
+In this way the resulting gases form a mixture of hydrogen, carbon,
+monoxide, and nitrogen, with a small percentage of carbon dioxide which
+usually escapes without reduction. The steam should have a pressure of
+11/2 to 2 atmospheres, and is produced and superheated in a zigzag coil
+fed with water from a neighboring boiler. The quantity of water required
+is very small, being only about 7 pints for each 1,000 cubic feet of
+gas, and, except on the first occasion when the apparatus is started,
+the coil is heated by some of the gas drawn from the holder, so that
+after the gas is lighted under the coil the superheater requires no
+attention.
+
+For boiler and furnace work the gas can be used direct from the
+generator; but where uniformity of pressure is essential, as for gas
+engines, gas burners, etc., the gas should pass into a holder. The
+latter somewhat retards the production, but the steam injector causes
+gas to be made so rapidly that a holder is easily filled against a back
+pressure of 1 in. to 11/2 in. of water, and at this pressure the generator
+can pass gas continuously into the holder, while at the same time it is
+being drawn off for consumption.
+
+The nature of the fuel required depends on the purpose for which the gas
+is used. If for heating boilers, furnaces, etc, coke or any kind of coal
+maybe used; but for gas engines or any application of the gas requiring
+great cleanliness and freedom from sulphur and ammonia it is best to use
+anthracite, as this does not yield condensable vapors, and is very free
+from impurities. Good qualities of this fuel contain over 90 per cent of
+carbon and so little sulphur that, for some purposes, purification is
+not necessary. For gas engines, etc., it is, however, better to pass
+the gas through some hydrated oxide of iron to remove the sulphureted
+hydrogen. The oxide can be used over and over again after exposure to
+the air, and the purifying is thus effected without smell or appreciable
+expense. Gas made by this process and with anthracite coal has no tar
+and no ammonia, and the small percentage of carbon dioxide present does
+not sensibly affect the heating power. A further advantage of this gas
+is that it cannot burn with a smoky flame, and there is no deposition of
+soot even when the object to be heated is placed over or in the flame,
+and this is of importance for the cylinder and valves of a gas engine.
+
+To produce 1,000 cubic feet only 12 lb. of anthracite are required,
+allowing 8 to 10 per cent, for impurities and waste; thus a generator
+A size, which produces 1,000 cubic feet per hour, needs only 12 lb. in
+that time, and this can be added once an hour or at longer intervals. No
+skilled labor is necessary, and in practice it is usual to employ a man
+who has other work to attend to near the generator, and to pay him a
+small addition to his usual wages.
+
+The comparative explosive force of coal gas and the Dowson gas
+calculated in the usual way is as 3.4:1, i. e., coal gas has 3.4 times
+more energy than the writer's gas. Messrs. Crossley, of Manchester, the
+makers of the Otto gas engines, have made several careful trials of this
+gas with some of their 31/2 horse power (nominal) engines, and in one
+trial they took diagrams every half-hour for nine consecutive days.
+These practical trials have shown that without altering the cylinder of
+the engine it is possible to admit enough of the Dowson gas to give
+the same power as with ordinary coal gas. It has been seen that the
+comparative explosive force of the two gases is as 3.4:1, but as it is
+well known the combustion of carbon monoxide proceeds at a comparatively
+slow rate, and for this reason, and because of the diluents present in
+the cylinder which affect the weaker gas more than coal gas, experience
+has shown that it is best to allow five volumes of the Dowson gas for
+one volume of coal gas, and then the same uniform power is obtained as
+with the latter.
+
+This gives very important economical results; for if the cost of the
+Dowson gas given in the tables as 41/4d., 3-1/3d., and 23/4d. per 1,000
+cubic feet, be multiplied by 5 there will be 1s. 91/4d., 1s. 43/4d., and 1s.
+23/4d., or a mean of 1s. 51/2d. for the equivalent of 1,000 cubic feet of
+coal gas, which usually costs from 3s. to 4s., and this represents an
+actual saving of about 50 to 60 per cent, in working cost. Another
+practical consideration is that coal gas requires 224 lb. to 250 lb. of
+coal per 1,000 cubic feet of gas, but the writer requires only 12 lb.
+per 1,000 cubic feet, and multiplying this by 5 to give the equivalent
+of 1,000 cubic feet of coal gas, for engine work, there are 60 lb.
+instead of 224 lb. to 250 lb. This is only 24 to 27 per cent, of the
+weight of the coal required for coal gas, and in many outlying districts
+this will effect an appreciable saving in the cost of transport.
+
+
+APPENDIX.
+
+   TABLE I.
+
+  _Generator A Size_ (producing 1,000 cubic feet per hour):
+    Anthracite to make gas at the rate of 1,000   s.  d.
+      cubic feet per hour=l2 lb x 9 working
+      hours=l08 lb., or say, 1 cwt. at 20s. a
+      ton....................................     1   0
+    Allowance for wages of attendant.........     1   0
+    Repairs and depreciation of generator,
+      gasholder, etc. (5 per cent. on Ll25)=
+      per working day........................     0   5
+    Interest on capital outlay, ditto........     0   5
+                                                 ______
+
+             Total...........................     2  10
+                                                  cub. ft.
+
+    Gas produced.............................     9.000
+    Less gas used for generating and
+       superheating steam.....................    1,000
+                                                  _____
+             Total effective gas for 2s. 10d.     8,000
+
+  Net cost 41/4 d. per 1,000 cubic feet.
+
+  TABLE II.
+
+  _Generator B Size_ (producing 1,500 cubic feet per hour)
+    Anthracite to make gas at the rate of 1,500   s.  d.
+      cubic feet per hour=18 lb. x 9 working
+      hours=162 lb., or, say, 11/2 cwt. 20s.
+      a ton..................................     1    6
+    Allowance for wages of attendant.........     1    0
+    Repairs and depreciation of generator,
+      gasholder, etc. (5 per cent, on L140)
+      =per working day.......................     0    51/2
+    Interest on capital outlay, ditto........     0    51/2
+                                                 ___  ___
+             Total...........................     3    5
+                                                 cub. ft.
+    Gas produced.............................    13,500
+    Less gas used for generating and
+      superheating steam.....................     1,200
+                                                 ______
+             Total effective gas for 3s. 5d..    12,300
+
+  Net cost 3 1/3d. per 1,000 cubic feet.
+
+  TABLE III.
+
+  _Generator C Size_ (producing 2,500 cubic feet per hour):
+    Anthracite to make gas at the rate of 2,500      s. d.
+    cubic feet per hour=30 lb. x 9 working
+    hours=270 lb. at 20s. a ton............          2  41/2
+    Allowance for wages of attendant.......          1  6
+    Repairs and depreciation of generator,
+      gasholder, etc. (5 per cent, on L160)=
+      per working day......................          0  61/2
+    Interest on capital outlay, ditto......          0  61/2
+                                                    _______
+             Total.........................          4 111/2
+
+                                                     cub. ft.
+    Gas produced...........................        22,500
+    Less gas used for generating and
+      superheating steam...................         1,500
+                                                   ______
+             Total effective gas for 4s. 111/2d      21,000
+
+  Net cost, say, 23/4 d. per 1,000 cubic feet.
+
+       *       *       *       *       *
+
+
+
+
+ON THE FLUID DENSITY OF CERTAIN METALS.
+
+[Footnote: Abstract of paper read before Section C (Chemical Science),
+British Association meeting, York.]
+
+By PROFESSOR W. CHANDLER ROBERTS, F.R.S., and T. WRIGHTSON.
+
+
+The authors described their experiments on the fluid density of metals
+made in continuation of those submitted to Section B at the Swansea
+meeting of the Association. Some time since one of the authors gave an
+account of the results of experiments made to determine the density of
+metallic silver, and of certain alloys of silver and copper when in a
+molten state. The method adopted was that devised by Mr. R. Mallet, and
+the details were as follows: A conical vessel of best thin Lowmoor plate
+(1 millimeter thick), about 16 centimeters in height, and having an
+internal volume of about 540 cubic centimeters, was weighed, first
+empty, and subsequently when filled with distilled water at a known
+temperature. The necessary data were thus afforded for accurately
+determining its capacity at the temperature of the air. Molten silver
+was then poured into it, the temperature at the time of pouring being
+ascertained by the calorimetric method. The precautions, as regards
+filling, pointed out by Mr. Mallet, were adopted; and as soon as the
+metal was quite cold, the cone with its contents was again weighed.
+Experiments were also made on the density of fluid bismuth; and two
+distinctive determinations gave the following results:
+
+  10.005 )
+         ) mean 10.039.
+  10.072 )
+
+The invention of the oncosimeter, which was described by one of the
+authors in the "Journal of the Iron and Steel Institute" (No. II.,
+1879, p. 418), appeared to afford an opportunity for resuming the
+investigation on a new basis, more especially as the delicacy of the
+instrument had already been proved by experiments on a considerable
+scale for determining the density of fluid cast iron. The following is
+the principle on which this instrument acts:
+
+If a spherical ball of any metal be plunged below the surface of a
+molten bath of the same or another metal, the cold ball will displace
+its own volume of molten metal. If the densities of the cold and molten
+metal be the same, there will be equilibrium, and no floating or sinking
+effect will be exhibited. If the density of the cold be greater than
+that of the molten metal, there will be a sinking effect, and if less a
+floating effect when first immersed. As the temperature of the submerged
+ball rises, the volume of the displaced liquid will increase or decrease
+according as the ball expands or contracts. In order to register these
+changes the ball is hung on a spiral spring, and the slightest change in
+buoyancy causes an elongation or contraction of this spring which can
+be read off on a scale of ounces, and is recorded by a pencil on a
+revolving drum. A diagram is thus traced out, the ordinates of which
+represent increments of volume, or, in other words, of weight of fluid
+displaced--the zero line, or line corresponding to a ball in a liquid of
+equal density, being previously traced out by revolving the drum without
+attaching the ball of metal itself to the spring, but with all other
+auxiliary attachments. By means of a simple adjustment the ball is kept
+constantly depressed to the same extent below the surface of the liquid;
+and the ordinate of this pencil line, measuring from the line of
+equilibrium, thus gives an exact measure of the floating or sinking
+effect at every stage of temperature, from the cold solid to the state
+when the ball begins to melt.
+
+If the weight and specific gravity of the ball be taken when cold,
+there are obtained, with the ordinate on the diagram at the moment of
+immersion, sufficient data for determining the density of the fluid
+metal; for
+
+W / W1 = D / D1
+
+the volumes being equal. And remembering that
+
+W (weight of liquid) = W1 (weight of ball) + x
+
+(where x is always measured as +_ve_ or -_ve_ floating effect), there is
+obtained the equation:
+
+       D1  x ( W1 + x)
+  D =  --------------- .
+            W1
+
+[TEX: D = \frac{D_1 \times (W_1 +x)}{W_1}]
+
+The results obtained with metallic silver are perhaps the most
+interesting, mainly from the fact that the metal melts at a higher
+temperature, which was determined with great care by the illustrious
+physicist and metallurgist, the late Henri St. Claire Deville, whose
+latest experiments led him to fix the melting point at 940 deg. Cent. The
+authors of the paper showed that the density of the fluid metal was 9.51
+as compared with 10.57, the density of the solid metal. Taking their
+results generally, it is found that the change of volume of the
+following metals in passing from the solid to the liquid state may be
+thus stated:
+
+               Specific       Specific
+   Metal.        Gravity,      Gravity,      Percentage of
+                 Solid.        Liquid.         Change.
+
+  Bismuth         9.82         10.055     Decrease of volume  2.3
+  Copper          8.8           8.217     Increase       "    7.1
+  Lead           11.4          10.37          "          "    9.93
+  Tin.            7.5           7.025         "          "    6.76
+  Zinc            7.2           6.48          "          "   11.10
+  Silver         10.57          9.51          "          "   11.20
+  Iron            6.95          6.88          "          "    1.02
+
+       *       *       *       *       *
+
+
+
+
+HYDROPHOBIA PREVENTED BY VACCINATION.
+
+
+M. Pasteur and other French savants have lately been devoting special
+attention to hydrophobia. The great authority on germs has, in fact,
+definitely announced that he does not intend to rest until he has made
+known the exact nature and life-history of this terrible disease, and
+discovered a means of preventing or curing it. The most curious result
+yet attained in this direction, however, has been announced by Professor
+V. Galtier, of the Lyons Veterinary School. This inquirer has found, in
+the first place, that if the virus of rabies be injected into the veins
+of a sheep, the animal does not subsequently exhibit any symptoms of
+hydrophobia. This in itself would be a sufficiently curious result
+to justify attention, though its importance, except as confirmatory
+testimony, becomes less striking when it is remembered that M. Pasteur
+has lately shown that the special _nidus_ of the disease appears to be
+the nervous tissue, and particularly the ganglionic centers. But there
+is this further curious consequence: sheep who have thus been treated
+through the blood, and who are afterwards inoculated in the ordinary
+way through the cellular tissue, as if by a bite, are proof against
+the disease. It is as though the injection into the veins acted as a
+vaccine. Twenty sheep were experimented upon; ten only were treated to
+the venous injection, and then all were inoculated through the cellular
+tissue. The ten which had been first "vaccinated" continue alive and
+well; they have not even shown any adverse symptoms. The other ten have
+all died of rabies. It remains to say why M. Galtier experimented
+upon sheep, and not upon dogs and cats, which usually communicate the
+disease. The incubation of the disease is much more rapid and less
+capricious in the sheep than in the dog or in man, and hence M. Galtier
+was able to get his results more certainly within a short period. Having
+succeeded so far, he is now justified in undertaking the more protracted
+series of observations which experiments upon the canine species will
+involve; and this he proposes to do. Experiments of this nature are not
+without a serious risk, and admiration is almost equally due to the
+courage and the intelligence of the experimentalist. But what will the
+anti-vaccinator say?--_Pall Mall Gazette_.
+
+       *       *       *       *       *
+
+
+
+
+ON DIPTERA AS SPREADERS OF DISEASE.
+
+By J.W. SLATER.
+
+
+The two-winged flies, in their behavior to man, stand in a marked
+contrast to all the other orders of insects. The Lepidoptera, the
+Coleoptera, the Neuroptera, the Hymenoptera no doubt occasion, in some
+of their forms at least, much damage to our crops. But none of them are
+parasitic in or upon our bodies; none of them persistently intrude into
+our dwellings, hover around us in our walks, and harass us with noise
+and constant attempts to bite, or at least to crawl upon us. Even the
+ants, except in a few tropical districts, rarely act upon the offensive.
+The Hemiptera contain one semi-parasitic species which has attained a
+"world-wide circulation," and one degraded, purely parasitic group.
+But the Diptera, among which the fleas are now generally included as a
+degenerated type, comprise more forms personally annoying to man than
+all the remaining insect orders put together. These hostile species are,
+further, incalculably numerous, and occur in every part of the globe.
+Mosquitoes swarm not merely in the swampy forests of the Orinoco or the
+Irrawaddy, but in the Tundras of Siberia, en the storm-beaten rocks of
+the Loffodens, and are even encountered by voyagers in quest of the
+North Pole. The common house fly was probably at one time peculiar to
+the Eastern Continent, but it followed the footsteps of the Pilgrim
+Fathers, and is now as great a nuisance in the United Slates and the
+Dominion as in any part of Europe. It is curious, but distressing, to
+note the tendency of evils to become international. We have communicated
+to America the house-fly and the Hessian fly, the "cabbage-white,"
+the small pox, and the cholera. She, in return, has given us the
+_Phylloxera_, a few visitations of yellow fever, the _Blatta gigantea_,
+and, climate allowing, may perhaps throw in the Colorado beetle as a
+make-weight. In this department, at least, free trade reigns undisputed.
+It is a singular thing that no beautiful, useful, or even harmless
+species of bird or insect seems capable of acclimatizing itself as do
+those characterized by ugliness and noisomeness.
+
+But, returning from this digression, we find in the Diptera the habit of
+obtrusion and intrusion, of coming in actual contact with our food and
+our persons, combined with another propensity--that of feeding upon
+carrion, excrement, blood, pus, and morbid matter of all kinds. This
+is a combination far more serious than is generally imagined. If the
+fly--which may at any moment settle upon our lips, our eyes, or upon
+an abraded part of our skin--were cleanly in its habits, we need feel
+little annoyance at its visits. Or if it were the most eager carrion
+devourer, but did not, after having dined, think it necessary to
+seek our company, we might hold it, as is done too hastily by some
+naturalists, a valuable scavenger. I fear, however, that I have already
+made too great a concession. So long as very many persons are suffering
+from disease--so long as many diseases are capable of being transmitted
+from the sick to the healthy--so long must any creature which is in the
+habit of flying about, and touching first one person and then another,
+be a possible medium of infection and death.
+
+Let us take the following case, by no means imaginary, but a
+generalization from occurrences far too frequent: A healthy man, sitting
+in his house or walking in the fields, especially in countries where the
+insectivorous birds have been shot down, suddenly feels a sharp prick on
+his neck or his cheek. Putting his hand to the place he perhaps crushes,
+perhaps merely brushes away, a fly which has bitten him so as to draw
+blood. The man thinks little of so trifling a hurt, but the next morning
+he finds the puncture exceedingly painful. An inflamed pimple forms,
+which quickly gets worse, while constitutional symptoms of a feverish
+kind come on. In alarm he seeks medical advice. The doctor tells him
+that it is a malignant pustule, and takes at once the most active
+measures. In spite of all possible skill and care the patient too often
+succumbs to the bite of a _mouche charbonneuse_, or carbuncle-fly. But
+has any kind of fly the property of producing malignant pustule by
+some specific inherent power of its own? Surely not. The antecedent
+circumstances are these: A sheep or heifer is attacked with the disease
+known in France as _charbon_, in Germany as _milz-brand_, and in England
+as _splenic fever_. Its blood on examination would be found plentifully
+peopled with bacteria. If a lancet were plunged into the body of the
+animal, and were then used to slightly scratch or cut the skin of a man,
+he would be inoculated with "charbon." The bite of the fly is precisely
+similar in its action. Its rostrum has been smeared with the poisoned
+blood, an infinitesimal particle of which is sufficient to inclose
+several of the disease "germs," and these are then transferred to the
+blood of the next man or animal which the fly happens to bite. The
+disease is reproduced as simply and certainly as the spores of some
+species of fern give rise to their like if scattered upon soil suitable
+for their growth. But flies which do not bite may transfer infection.
+Every one must know that if blood be spilt upon the ground a crowd of
+flies will settle upon and eagerly absorb it. Animals suffering from
+splenic fever in the later stages of the disease sometimes emit bloody
+urine. Often they are shot or slaughtered by way of stamping out the
+plague, and their carcasses are buried deep in the ground. But some loss
+of blood is sure to happen, and this will mostly be left to soak into
+the ground. Here again the flies will come, and their feet and mouth
+will become charged with the contagion. Such a fly, settling upon
+another animal or a man, and selecting--as it will do by preference, if
+such exist--a wound, or a place where the skin is broken, will convey
+the disease.
+
+Again, M. Pasteur has thoughtfully pointed out that if an animal has
+died of splenic fever, and has been carefully buried, the earth-worms
+may bring up portions of infectious matter to the surface, so that sheep
+grazing, or merely being folded over the spot in question, may take the
+plague and die. Hence be wisely counsels that the bodies of such animals
+should be buried in sandy or calcareous soils where earth-worms are not
+numerous. But it is perfectly legitimate to go a step farther. If such
+worm-borings retain the slightest savor of animal matter, flies will
+settle upon them and will convey the infectious dust to the most
+unexpected places, giving wings to the plague.
+
+Now it is very true that no one has seen a fly feasting upon the blood
+of a heifer or sheep dying or just dead of splenic fever, has then
+watched it settle upon and bite some person, and has traced the
+following stages of the disease. But it is positively known that a
+person has been bitten by a fly, and has then exhibited all the symptoms
+of charbon, the place of the bite being the primary seat of the
+infection. We know also, beyond all doubt, the eagerness with which
+flies will suck up blood, and we likewise know the strange persistence
+of the disease "germs."
+
+Again, the avidity of flies for purulent matter is not a thing of mere
+possibility. In Egypt, where ophthalmia is common, and where the "plague
+of flies" seems never to have been removed, it is reported as almost
+impossible to keep these insects away from the eyes of the sufferers.
+The infection which they thus take up they convey to the eyes of persons
+still healthy, and thus the scourge is continually multiplied.
+
+A third case which seems established beyond question is the agency of
+mosquitoes in spreading elephantiasis. These so-called sanitary agents
+suck from the blood of one person the Filariae, the direct cause of the
+disease, and transfer them to another. The manner in which this process
+is effected will appear simple enough if we reflect that the mosquito
+begins operations by injecting a few drops of fluid into its victim, so
+as to dilute the blood and make it easier to be sucked.
+
+So much being established it becomes in the highest degree probable that
+every infectious disease may be, and actually is, at times propagated
+by the agency of flies. Attention turned to this much neglected quarter
+will very probably go far to explain obscure phenomena connected with
+the distribution of epidemics and their sudden outbreaks in unexpected
+quarters. I have seen it stated that in former outbreaks of pestilence
+flies were remarkably numerous, and although mediaeval observations on
+Entomology are not to be taken without a grain of salt, the tradition
+is suggestive. Perhaps the Diptera have their seasons of unusual
+multiplication and emigration. A wave of the common flea appears to have
+passed over Maidstone in August, 1880.
+
+We now see the way to some practical conclusions not without importance.
+Recognizing a very considerable part of the order of Diptera, or
+two-winged flies, as agents in spreading disease, it surely follows
+that man should wage war against them in a much more systematic and
+consistent manner than at present. The destruction of the common
+house-fly by "_papier Moure_," by decoctions of quassia, by various
+traps, and by the so-called "catch 'em alive," is tried here and there,
+now and then, by some grocer, confectioner, or housewife angry at the
+spoliation and defilement caused by these little marauders. But there
+is no concerted continuous action--which after all would be neither
+difficult nor expensive--and consequently no marked success. Experiments
+with a view of finding out new modes of fly-killing are few and far
+between.
+
+Every one must occasionally have seen, in autumn, flies as if cemented
+to the window-pane, and surrounded with a whitish halo. That in some
+seasons numbers of flies thus perish--that the phenomenon is due to a
+kind of fungus, the spores of which readily transfer the disease from
+one fly to another--we know. But here our knowledge is at fault. We
+have not learnt why this fly-epidemic is more rife in some seasons than
+others. We are ignorant concerning the methods of multiplying this
+fungus at will, and of launching it against our enemies. We cannot tell
+whether it is capable of destroying _Stomoxys calcitram_, the blowflies,
+gadflies, gnats, mosquitoes, etc. Experiment on these points is rendered
+difficult by the circumstance that the fungus is rarely procurable
+except in autumn, when some of the species we most need to destroy are
+not to be found. Another question is whether the fungus, if largely
+multiplied and widely spread, might not prove fatal to other than
+Dipterous insects, especially to the Hymenoptera, so many of which,
+in their character of plant-fertilizers, are highly useful, or rather
+essential to man.
+
+Another fungus, the so-called "green muscardine" (_Isaria destructor_),
+has been found so deadly to insects that Prof. Metschnikoff, who is
+experimenting upon it, hopes to extirpate the _Phylloxera_, the Colorado
+beetle, etc., by its agency.
+
+Coming to better known and still undervalued fly-destroyers, we have
+interfered most unwisely with the balance of nature. The substitution of
+wire and railings for live fences in so many fields has greatly lessened
+the cover both for insectivorous birds and for spiders. The war waged
+against the latter in our houses is plainly carried too far. Whatever
+may be the case at the Cape, in Australia, or even in Southern Europe,
+no British species is venomous enough to cause danger to human beings.
+Though cobwebs are not ornamental, save to the eye of the naturalist,
+there are parts of our houses where they might be judiciously tolerated:
+their scarcity in large towns, even where their prey abounds, is
+somewhat remarkable.
+
+But perhaps the most effectual phase of man's war against the flies will
+be negative rather than positive, turning not so much on putting to
+death the mature individuals as in destroying the matter in which the
+larvae are nourished. Or if, from other considerations, we cannot
+destroy all organic refuse, we may and should render it unfit for the
+multiplication of these vermin. We have, indeed, in most of our large
+towns and in their suburbs, abolished cesspools, which are admirable
+breeding-places for many kinds of Diptera, and which sometimes presented
+one wriggling mass of larvae. We have drained many marshes, ditches,
+and unclean pools, rich in decomposing vegetable matter, and have thus
+notably checked the propagation of gnats and midges. I know an instance
+of a country mansion, situate in one of the best wooded parts of the
+home counties, which twenty years ago was almost uninhabitable, owing to
+the swarms of gnats which penetrated into every room. But the present
+proprietor, being the reverse of pachydermatous, has substituted covered
+drains for stagnant ditches, filled up a number of slimy ponds as
+neither useful nor ornamental, and now in most seasons the gnats no
+longer occasion any annoyance.
+
+But if we have to some extent done away with cesspools and ditches, and
+have reaped very distinct benefit by so doing, there is still a grievous
+amount of organic matter allowed to putrefy in the very heart of our
+cities. The dust bins--a necessary accompaniment of the water-carriage
+system of disposing of sewage--are theoretically supposed to be
+receptacles mainly for organic refuse, such as coal-ashes, broken
+crockery, and at worst the sweepings from the floors. In sober fact
+they are largely mixed with the rinds, shells, etc., of fruits and
+vegetables, the bones and heads of fish, egg-shells, the sweepings out
+of dog-kennels and henhouses, forming thus, in short, a mixture of evil
+odor, and well adapted for the breeding-place of not a few Diptera.
+
+The uses to which this "dust" is put when ultimately fetched away are
+surprising: without being freed from its organic refuse it is used to
+fill up hollows in building-ground, and even for the repair of roads. A
+few weeks ago I passed along a road which was being treated according
+to the iniquity of Macadam. Over the broken stones had been shot, to
+consolidate them, a complex of ashes, cabbage-leaves, egg and periwinkle
+shells, straw, potato-parings, a dead kitten (over which a few
+carrion-flies were hovering), and other promiscuous nuisances. The road
+in question, be it remarked, is highly "respectable," if not actually
+fashionable. The houses facing upon it are severely rated, and are
+inhabited chiefly by "carriage people." What, then, may not be expected
+in lower districts?
+
+Much attention has lately been drawn to the fish trade of London. It has
+_not_, however, come out in evidence that the fish retailers, if they
+find a quantity of their perishable wares entering into decomposition,
+send out late in the evening a messenger, who, watching his opportunity,
+throws his burden down in some plot of building land, or over a fence.
+When I say that I have seen in one place, close alongside a public
+thoroughfare, a heap of about fifty herrings, in most active
+putrefaction and buzzing with flies, and some days afterward, in another
+place, some twenty soles, it will be understood that such nuisances
+can only be occasioned by dealers. To get rid of, or at least greatly
+diminish, carrion-flies, house-flies, and the whole class of winged
+travelers in disease, it will be, before all things, essential to
+abolish such loathsome malpractices. The dustbins must cease being made
+the receptacle for putrescent and putrescible matter, the destruction of
+which by fire should be insisted upon.
+
+The banishment of slaughter-houses to some truly rural situation, where
+the blood and offal could be at once utilized, would be another step
+toward depriving flies of their pabulum in the larva state. An equally
+important movement would be the substitution of steam or electricity for
+horsepower in propelling tram-cars and other passenger carriages, with a
+view to minimize the number of horses kept within greater London. Every
+large stable is a focus of flies--_Journal of Science_.
+
+       *       *       *       *       *
+
+
+
+
+ON THE RELATIONS OF MINUTE ORGANISMS TO CERTAIN SPECIFIC DISEASES.
+
+
+At the recent Medical Congress in London, Professor Klebs undertook to
+answer the question: "Are there specific organized causes of disease?"
+
+A short historical review of the various opinions of mankind as to the
+origin of disease led, the speaker thought, to the presumption that
+these causes were specific and organized.
+
+If we now, he said, consider the present state of this question, the
+three following points of view present themselves as those from which
+the subject may be regarded:
+
+I.--We have to inquire whether the lower organisms, which are found in
+the diseased body, may arise there spontaneously; or whether even they
+may be regarded as regular constituents of the body.
+
+II.--The morphological relations of these organisms have to be
+investigated, and their specific nature in the different morbid
+processes has to be determined.
+
+III.--We have to inquire into their biological relations, their
+development inside and outside the body, and the conditions under which
+they are able to penetrate into the body, and there to set up disease.
+
+_First_.--With regard to the first question, that of the possibility of
+spontaneous generation, the speaker gave a decided negative.
+
+_Second and third_.--There is in microscopic organisms a difference of
+form corresponding, as a rule, to difference of function. The facts
+regarding these various lower forms are briefly reviewed.
+
+"Three groups of hyphomycetae, algae, and schizomycetae, have been
+demonstrated to occur in the animal and human organism in infective
+diseases. Their significance increases with the increase of their
+capacity for development in the animal body. This depends partly upon
+their natural or ordinary conditions of life, but partly also, and that
+in a very high degree, upon their power of adaptation, which, as Darwin
+has shown, is a property of all living things, and causes the production
+of new species with new active functions.
+
+"1. The hyphomycetae, on account of their needing an abundant supply
+of oxygen, give rise to but few morbid processes, and these run their
+course on the surface of the body, and are hence relatively of less
+importance. It will be sufficient here to refer to the forms, achorion,
+trichophyton, oidium, aspergillus, and the diseases produced by them,
+favus, ringworm, and thrush, to show this peculiarity. Nevertheless, we
+see that these organisms also (as was proved by the older observations
+of Hannover and Zenker) may, under certain circumstances, penetrate into
+the interior of the organs. Grawitz, moreover, has recently shown that
+their faculty of penetrating into the interior of the organism, and
+there undergoing further development, depends on their becoming
+accustomed to nitrogenous food.
+
+"2. Only one of the algae, viz., leptothrix, has as yet acquired any
+importance as a producer of disease. It gives rise to the formation of
+concretions, and that not only in the mouth, but also, as I have shown,
+in the salivary ducts and urinary bladder.
+
+"Another alga, the sarcina of Goodsir, may indeed pass through the
+organism, without, however, producing in its passage either direct
+or indirect disturbances. It seems more worthy of note that many
+schizomycetae, and especially the group of bacilli, are evidently nearly
+allied to the algae in their morphological and vegetative relations--so
+as to be assigned to this class by several authors, and especially by
+Cienkowski.
+
+"The schizomycetae furnish, without doubt, by far the most numerous
+group of infective diseases. We distinguish within this group two
+widely different series of forms, which we will speak of as bacilli and
+cocco-bacteria respectively. The former, which was first exhaustively
+described by Ferdinand Cohn, and the pathological importance of which,
+especially in relation to the splenic disease of cattle, was first shown
+by Koch, consist of threads, in the interior of which permanent or
+resting-spores are developed. These spores becoming free, are able,
+under suitable conditions of life, again to develop into threads. The
+whole development of these organisms, and especially the formation
+of spores, is completed on the surface of the fluids, and under the
+influence of an abundant supply of oxygen.
+
+"The number of affections in which these organisms have been found,
+and which may be to a certain extent produced artificially by the
+introduction of these organisms into healthy animal bodies, has been
+largely increased since the discovery of Koch, that the bacteria of
+splenic fever (anthrax) belong to this group. Under this head must be
+placed the bacillus malarise (Klebs and Tommassi-Crudeli), the bacillus
+typhi abdominalis (Klebs, Ebert), the bacillus typhi exanthematici
+(Klebs, observations not yet published), the bacillus of hog-cholera
+(Klein), and, finally the bacillus leprosus (Neisser). It would exceed
+the time appointed were I to attempt to describe these forms more
+minutely. This may, perhaps, be better reserved for discussion and
+demonstration.
+
+"Alongside of these general infective diseases produced by bacilli,
+local affections also occur, which indicate the presence of these
+organisms at the point where disease begins. As an example of these
+processes, which probably occur in various organs, I would mention
+gastritis bacillaris, of which I shall show you preparations. In this,
+we can trace the entrance of the bacilli into the peptic glands, as well
+as their further distribution in the walls of the stomach, and in the
+vascular system.
+
+"The second group of the pathogenetic schizomycetae I propose to call,
+with Billroth, cocco-bacteria, because they consist of collections of
+micrococci, which are capable of transforming themselves into short
+rods. The former usually form groups united by zooegloea; by prolongation
+of the cocci rods are formed, which sprout out, break up by division
+into chains, and further lead again to the formation of resting masses
+of cocci. I distinguish, further, in this group, two genera--the
+microsporina and the monadina; in the former of which the micrococci are
+collected into spherical lumps, in the latter into layers. The one class
+is developed in artificial cultivation fluid, the other on the surface.
+The former requires a medium poor in oxygen, the latter a medium rich in
+oxygen, for their development.
+
+"Among the affections produced by microsporina, I reckon especially the
+septic processes, and also true diphtheria. On the other hand, to the
+processes produced by monadina belong especially a large series of
+diseases, which according to their clinical and anatomical features,
+may be characterized as inflammatory processes, acute exanthemata, and
+infective tumors, or leucocytoses. Of inflammatory processes, those
+belong here which do not generally lead to suppuration, such as
+rheumatic affections, including the heart, kidney, and liver affections,
+which accompany this process, sequelae which, as is well known,
+lead more especially to formation of connective tissue, and not to
+suppuration. Here, also, belong croupous pneumonia, the allied disease
+erysipelas, certain puerperal processes, and finally, parotitis
+epidemica, or mumps.
+
+"Among the acute exanthemata, the following may, up to the present time,
+be placed in this group; variola-vaccina, scarlatina, and measles.
+
+"The group of infective tumors is represented by tuberculosis, syphilis,
+and glanders. Throughout the whole group of cocco-bacteria the
+demonstration of organisms in the diseased parts encounters difficulties
+which vary considerably in the different kinds."
+
+The speaker concluded by describing the methods (now well known) by
+which the powers of the different organisms are tested.
+
+He also referred to Pasteur's, Chauveau's, and Toussaint's recent
+experiments.
+
+His conclusion was that the specific communicable diseases are produced
+by specific organisms.
+
+       *       *       *       *       *
+
+
+
+
+THE CENTENARY OF THE DISCOVERY OF URANUS.
+
+By W. F. DENNING, F.R.A.S.
+
+
+The year 1781 was signalized by an astronomical discovery of great
+importance, and one which marked the epoch as memorable in the annals
+of science. A musician at Bath, William Herschel by name, who had been
+constructing some excellent telescopes and making a systematic survey of
+the heavens, observed an object on the night of March 13 of that year,
+which ultimately proved to be a large planet revolving in an orbit
+exterior to that of Saturn. The discovery was as unique as it was
+significant. Only five planets, in addition to the Earth, had hitherto
+been known; they were observed by the ancients, and by each succeeding
+generation, but now a new light burst upon men. The genius of Herschel
+had singled out from the host of stars which his telescope revealed
+an object the true character of which had evaded human perception for
+thousands of years!
+
+[Illustration: FIG. 1.--APPROXIMATE PLACE OF URANUS AMONGST THE STARS AT
+ITS DISCOVERY ON MARCH 13, 1781]
+
+The centenary of this remarkable advance in knowledge naturally recalls
+to mind the circumstances of the discovery, and makes us inquisitive to
+know what new facts have been gleaned of Herschel's planet, now that
+a hundred years have passed away, and we are enabled to look back and
+review the vast amount of labor which has been accomplished in this wide
+and attractive field of astronomical research. We may learn what new
+features have been discerned of the new body, and what additional
+discoveries in connection with other planets unknown in Herschel's day,
+have been effected by aid of the powerful telescopes which have been
+devoted to the work. We do not, however, intend dealing with the general
+question of planetary discovery, for at a glance we are impressed with
+its magnitude. While a century ago five planets only were known, we now
+have some two hundred and thirty of these bodies, and the stream of
+discovery flows on without abatement through each succeeding year. The
+detection of Uranus seems, indeed, to have been the prelude to many
+similar discoveries, and to have offered the incentive to greater
+diligence and energy on the part of observers in various parts of the
+world.
+
+[Illustration: Fig. 2.--ORBITS OF THE URANIAN SATELLITES.]
+
+Many great discoveries have resulted from accident; and the leading
+facts attending that of Uranus prove that, in a large measure, the
+result was brought about in a similar way. Herschel, as he unwearyingly
+swept the heavens night after night, was in quest of sidereal
+wonders--such as double stars and nebulae--and he happened to alight
+upon the new planet in a purely chance way. He had no expectation of
+finding such a remarkable object, and indeed, when he had found it,
+wholly mistook its character. There could be no doubt that it was a body
+wholly dissimilar to the fixed stars, and it was equally certain that it
+could not be a nebula. It had a perceptible disk, for when it had first
+come under the critical eye of its discoverer he had noticed immediately
+that its appearance differed widely from the multitude of objects which
+crossed the field of his telescope. He had been accustomed to see hosts
+of stars pass in review, and their aspect was in one respect similar,
+namely, they were invariably presented as points of light incapable of
+being sensibly magnified, even with the highest powers. True, there was
+a great variety of apparent brightness in these objects and a singular
+diversity of configuration, but there was no exception to the invariable
+feature referred to. The point of light was constant, and no striking
+exception was anticipated until one night--March 13, 1781--Herschel
+being intently engaged in the examination of some small stars in the
+region of Gemini, brought an object under the range of, his telescope,
+which his eye at once selected as one of anomalous character.
+
+Applying a higher power, he noticed that it exhibited a planetary disk,
+but his instrument failed to define it with sufficient distinctness, and
+hence he became doubtful as to its real nature. The object was found to
+be in motion, and subsequent observations led him to the assumption that
+it must be a comet of rather exceptional type. This appeared to be the
+best explanation of the strange body, for history contained many records
+of curious comets, some of which were observed as nearly circular
+patches of nebulous light, and probably of similar aspect to the object
+then visible; and apart from this it must be remembered that the idea of
+a large planet exterior to Saturn was a fact of such momentous import
+that Herschel, with a due regard to that modesty which accompanies
+true genius, refrained from attaching such an interpretation to his
+observations. He was content to direct the notice of astronomers to it
+as a phenomenon requiring close attention, and suggested that it might
+be a comet in consequence of its motion and the faint and somewhat
+ill-defined character of its appearance.
+
+From the earliest ages five planets only were known, and the discovery
+of another large planet beyond the sphere of Saturn must at once
+revolutionize existing ideas as to the range of the solar system, and
+immediately take rank as a scientific event of equal interest to the
+discovery of the moons of Jupiter or the rings of Saturn, which each in
+their day impressed men with new ideas of the celestial mechanism. But
+the truth could not long be delayed. The new body being watched and its
+orbit rigorously computed from a series of observed positions revealed
+its true character, and Herschel was awarded the honor due to the author
+of a discovery of such importance. His diligence and pertinacity alone
+had enabled him to search out from among the multitude of stars thickly
+strewn over the firmament this unknown and well-nigh invisible planet
+which, during all the preceding years of the world's history, had eluded
+human perception. Men had been all unconscious of its existence as it
+had been slowly completing its circuits around the sun, obedient to the
+same laws as the other planets of the solar system, and awaiting the
+hour when the unfailing eve of Herschel should introduce it as the faint
+and far-off planet girding our system within its expansive folds.
+
+As soon as the existence of the new orb was confirmed and the fact
+rendered indisputable, the question naturally arose whether it had ever
+been seen in former years by the authors of star catalogues, who could
+hardly have overlooked an object like this though its planetary nature
+had manifestly escaped detection. It was just perceptible to the naked
+eye, shining like a star of the sixth magnitude, and ought to have been
+distinguished by those who had reviewed the heavens with the purpose
+of determining and mapping the positions of the stars. Reference was,
+therefore, made to the chief catalogues, when it was found at once that
+the planet had been unquestionably observed by Tobias Mayer, Le Monnier,
+Bradley, and Flamsteed. It was several times noted by these observers:
+by Le Monnier no less than twelve times, and by Flamsteed on six
+occasions; and it is remarkable that in every instance its true
+character escaped detection. Neither its special appearance nor its
+motion attracted attention, so that it was merely catalogued as an
+ordinary fixed star. Thus Herschel was not anticipated in his discovery.
+It remained for him, in 1781, to note its exceptional aspect, and to
+specify it as an object requiring critical investigation. But the early
+observations above alluded to served a useful purpose in testing the
+accuracy of the computed orbit, for without waiting many years to
+compare the theoretical and observed positions, astronomers had in these
+old records a reliable series of points through which the previous
+course of the planet could be traced.
+
+The calculations showed that its mean distance from the sun was some
+1,750,000,000 miles, and that a revolution was completed in about
+eighty-four years. It was also found to be a very large planet, greatly
+exceeding either Mercury, Venus, the Earth, or Mars, though considerably
+inferior to either Jupiter or Saturn.
+
+Here, then, was a discovery of the utmost importance, and one of the
+most salient additions to our knowledge which the telescope had ever
+achieved. The new planet was now definitely assigned its proper place in
+the solar system, and was regarded as of equal significance with the
+old planets. True, the new planet of Herschel could not be compared as
+regards its visible aspect with the other previously known members of
+our system, but it was nevertheless an object of equal weight. Its vast
+distance alone rendered it faint. It formed one of the constituent parts
+of the solar system, which, though separated by immense intervals of
+space, are yet coherent by the far-reaching effects of gravitation.
+There is, indeed, a bond of harmony between the series of planetary
+orbits, which exhibit a marked degree of regularity in their successive
+distances from the sun; and though they are not connected by any visible
+links, they are firmly held together by unseen influences, and their
+motions are subject to certain laws which have been revealed by
+centuries of observation.
+
+The question of suitably naming the new planet soon came to the fore.
+Herschel himself proposed to designate it the "Georgium Sidus," in honor
+of his patron, George III., just as Galileo had called the satellites
+of Jupiter the "Medicean stars," after Cosmo de' Medici. But La Place
+proposed that the planet should be named after its discoverer; and thus
+it was frequently referred to as "Herschel," and sometimes as "The
+Herschelian planet." Astronomers on the continent objected to this
+system of personal nomenclature, and argued that the new body should
+receive an appellative in accordance with those adopted for the old
+planets, which had been selected from the heathen mythology. Several
+names were suggested as suitable (on the basis of this principle), and
+ultimately the one advanced by Bode received the most favor, and the
+planet thereafter was called "Uranus."
+
+The varying positions of the new body as observed on successive nights
+were determined by comparisons with a group of six small stars, termed
+by Herschel [Greek: alpha, beta, gamma, delta, epsilon] and afterwards
+formed into a constellation under the designation of "Britannia," though
+it does not appear that this little asterism is acknowledged as one of
+our constellations. Its position is about midway between Taurus and
+Gemini, and the following are the principal stars computed for 1881.0,
+as given by Mr. Marth:
+
+  Star.   Magnitude.  Right Ascension.   Declination.
+                      h. m.   s.
+  alpha     9.0       5  42  6.06        23 deg. 35'  6.7" N.
+  eta       8.7       5  43 17.82        23  26'  7.2  N.
+  theta     8.8       5  44  0.99        23  53' 30.8  N.
+  epsilon   8.8       5  45 40.68        23  34' 46.8  N.
+
+The stars are therefore merely telescopic, and are confined to a small
+area of space, so that the propriety of adopting the group as a distinct
+constellation is very questionable. Their positions close to Uranus at
+the time of its discovery, and the fact that the planet's motion was
+detected by means of comparisons with them, has given to these stars an
+historical interest which in future years must often attract the student
+to their reobservation. But it would be unwise, as forming a bad
+precedent, to accept a group of stars of this inferior type as meriting
+to rank among the old constellations, when we have numbers of richer
+groups, situated on their confines, which first deserve such a
+distinction. However special or unique the circumstances connected with
+certain telescopic stars may be, and however necessary it may appear
+to signalize them by a specific title, we are inclined to question the
+adoption of such means as likely to exercise a wrong influence,
+inasmuch as it may hereafter originate further innovations of a similar
+character, and ultimate complications will be certain to arise.
+
+Soon after the discovery of Uranus it was suspected that the planet
+was encircled, like Saturn, by a luminous ring, but on subsequent
+observation this was not confirmed, and no such appendage has ever been
+revealed in the more perfected instruments of our own times. Indeed, if
+Uranus displays a peculiarity of constitution in any way analogous to
+the ring system of Saturn, it must be of the most minute character so as
+to have thus evaded telescopic scrutiny during a hundred years.
+
+The discovery soon attracted the notice of royalty, and the reigning
+sovereign, George III., anxious to practically express his appreciation
+of the valuable labors of Herschel, awarded him a pension of L200 a year
+and furnished him with a residence at Slough, near Windsor, and the
+means to erect a gigantic telescope with which he might be enabled
+to continue his important researches. This instrument consisted of a
+reflector on the "Front-view" construction, with a speculum 4 feet in
+diameter and of 40 feet focal length. Upon its completion, Herschel
+immediately began to observe the region of the new planet with the idea
+of discovering any satellites which might belong to it, for analogy
+suggested that it was surrounded by a numerous retinue of such bodies.
+He was soon successful, for, on the night of January 11, 1787. he saw
+two minute objects near the planet, which renewed observations revealed
+to be satellites; and he detected two additional ones in 1790, and two
+others in 1794, making six in all. But the observations were of extreme
+difficulty. The path of the planet frequently passed near minute stars,
+and it became hard to distinguish between them and the suspected
+satellites. Herschel, however, considered he had obtained conclusive
+evidence of the existence of six satellites with sidereal periods
+ranging from 5d. 21h. 25m. to 107d. 16h. 39m., and his means of
+observation being much superior to those possessed by any of his
+contemporaries it was impossible to have corroborative testimony.
+
+The matter was thus allowed to rest until the middle of the present
+century, when Lassell, in the pure sky at Malta, endeavored to reobserve
+the satellites with a two-foot reflector. This instrument was considered
+superior to Herschel's telescope; and the atmosphere at this station
+being decidedly more suitable for such delicate observations than
+in England, it was removed there for the express purpose of dealing
+successfully with objects of extreme difficulty. The results were very
+important. Mr. Lassell became convinced that Uranus had only four
+satellites, and that if any others existed they remained to be
+discovered. Two of these were found to be identical with those seen by
+Herschel in 1787, and now called Titania and Oberon. The other two,
+Ariel and Umbriel, could not be identified with any of those alleged to
+have been previously detected by Herschel, so that the inference was
+that they were new bodies, and that the priority of discovery was due to
+Mr. Lassell; whence it also followed that the older observations were
+erroneous, and that in fact Herschel had been entirely mistaken with
+regard to the four satellites he believed he had detected subsequently
+to 1787.
+
+In November, 1873, a fine twenty-six-inch object glass, by Alvan Clark,
+was mounted at the U. S. Naval Observatory at Washington, and it was
+soon employed upon the difficult task of solving the problem as to the
+exact periods of the Uranian satellites. This was very satisfactorily
+effected, and with distinct and conclusive favor to Mr. Lassell, whose
+observations were fully corroborated. Only four satellites could be
+distinguished by the American observers, and their periods, as computed
+from a valuable series of measures, agreed with those previously derived
+at Malta. In Appendix I. to the "Washington Observations" for 1873,
+Prof. Newcomb gave a valuable summary of results--the first obtained, be
+it noted, with that splendid instrument which soon afterward, in 1877,
+revealed the satellites of Mars--which included the elements of the
+satellites of Uranus as follows:
+
+  Mean Longitude.
+
+      Satellite.      Epoch 1871.     Radius of        Period of
+                    Dec. 31, W.M.T.     Orbit.      Revolution in days.
+    I. Ariel........       21.83 deg.       13.78"          2.52038
+   II. Umbriel.....        13.52        19.20           4.14418
+  III. Titania.....       229.93        31.48           7.70590
+   IV. Oberon......       154.83        42.10          13.43327
+
+Speaking of the comparative brightness of the satellites, Prof. Newcomb
+says:
+
+"The greater proximity of the inner satellites to the planet makes it
+difficult to compare them photometrically with the outer ones, as actual
+feebleness of light cannot be distinguished from difficulty of seeing
+arising from the proximity of the planet. However, that Umbriel is
+intrinsically fainter than Titania is evinced by the fact that, although
+the least distance of the latter is somewhat less than the greatest
+distance of the former, there is never any difficulty in seeing it in
+that position. From their relative aspects in these respective positions
+I judge Umbriel to be about half as bright as Titania. Ariel must be
+brighter than Umbriel, because I have never seen the latter unless it
+was farther from the planet than the former at its maximum distance....
+I think I may say with considerable certainty that there is no satellite
+within 2' of the planet, and outside of Oberon, having one-third the
+brilliancy of the latter, and therefore that none of Sir William
+Herschel's supposed outer satellites can have any real existence. The
+distances of the four known satellites increase in so regular a way that
+it can hardly be supposed that any others exist between them. Of what
+may be inside of Ariel it is impossible to speak with certainty, since
+in the state of atmosphere which prevails during our winter all the
+satellites named disappear at 10" from the planet."
+
+Prof. Newcomb mentions that no systematic search for new satellites
+was undertaken because it must have interfered with the fullness and
+accuracy of the micrometer measures of the old satellites, which
+constituted the main purpose of the observations. Some faint objects
+were occasionally glimpsed near the planet, and their relative places
+determined, but they were never found to accompany Uranus. The fact,
+therefore, that no additional satellites were discovered is not to
+be regarded as a strong point in favor of the theory of their
+non-existence, because the great power and excellence of the telescope
+was expressly directed to the attainment of other ends; and moreover the
+season in which the planet came to opposition was distinctly unfavorable
+for the prosecution of a rigorous search for new satellites. There
+can, however, be no doubt that the analogies of the planetary systems
+interior to Uranus plainly suggest that this planet is attended by
+several satellites which the power of our greatest telescopes has
+hitherto failed to reveal; and that it is in this direction and that of
+Neptune we may anticipate further discoveries in future years when the
+conditions are more auspicious and the work is entered upon with special
+energy, aided by instruments of even greater capacity than those which
+have already so far conduced to our knowledge of the heavenly bodies.
+
+Notwithstanding the extreme difficulty with which the Uranian satellites
+are observed, the two brighter ones, Titania and Oberon, discovered by
+William Herschel in 1787, have been occasionally detected in telescopes
+of moderate power, and identified by means of an ephemeris which has
+shown that the computed positions approximately agree with those
+observed. During the last few years Mr. Marth has published ephemerides
+of the satellites of both Saturn and Uranus, and many amateurs have to
+acknowledge the valuable aid rendered by these tables, which supply a
+ready means of identifying the satellites, and thus act as an incentive
+to observers who are induced to pursue such work for the sake of the
+interesting comparisons to be made afterward. In one exceptional
+instance the two outer satellites of Uranus appear to have been glimpsed
+with an object glass of only 43 inches aperture, and the facts are given
+in detail in the "Monthly Notices of the R.A.S.," April 1876, pp. 294-6.
+The observations were made in January, February, and March, 1876, by
+Mr. J.W. Ward, of Belfast; and the positions of the satellites, as he
+estimated them on several nights, are compared with those computed, the
+two sets presenting tolerably good agreement. Indeed the corroborations
+are such as to almost wholly negative any skepticism, though such
+extraordinary feats should always be received with caution.
+
+In this particular case the chances of being misled are manifold; even
+Herschel himself fell into error in taking minute stars to be satellites
+and actually calculating their periods; so that when we remember the
+difficulties of the question our doubts are not altogether dispelled.
+Extreme acuteness of vision will, in individual instances, lead to
+success of abnormal character, and certainly in Mr. Ward's case the
+remarkable accordances in the observed and calculated positions appear
+to be conclusive evidence that he was not mistaken.
+
+It will be readily inferred that the great distance and consequent
+feebleness of Uranus must render any markings upon the disk of the
+planet beyond the reach of our best telescopes; and indeed this appears
+to have been a matter of common experience. Though the surface has been
+often scanned for traces of spots, we seldom find mention that any have
+been distinguished. Consequently the period of rotation has yet to be
+determined. It is true that an approximate value was assigned by Mr.
+T.H. Buffham from observations with a nine-inch reflector in 1870 and
+1872. but the materials on which the computation was based were slender
+and necessarily somewhat uncertain, so that his period of about twelve
+hours stands greatly in need of confirmation. The bright spots and zones
+seen on the disk in the years mentioned appear to have entirely eluded
+other observers, though they are probably phenomena of permanent
+character and within reach of instruments of moderate size. Mr. Buffham
+[1] thus describes them:
+
+[Footnote 1: "Monthly Notices K. A. S.," January, 1873.]
+
+"1870, Jan. 25, 11h. to 12h. in clear and tolerably steady air; power
+132 showed that the disk was not uniform. With powers 202 and 3.0, two
+round, bright spots were perceived, not quite crossing the center but a
+little nearer to the eastern side of the planet, the position angle of a
+line passing through their centers being about 20 and 200--ellipticity
+of Uranus seemed obvious, the major axis lying parallel to the line of
+the spots.
+
+"Jan. 27, 10h. to 101/2h.; some fog, and definition not good, but the
+appearance of the spots was almost exactly the same as on the 25th."
+
+On March 19 glimpses were obtained of a light streak and two spots.
+On April 1, 4, 6, and 8, a luminous zone was seen on the disk, and
+in February and March, 1872, when observations were resumed, certain
+regions were noted brighter than others, and underwent changes
+indicating the rotation of the planet in a similar direction to that
+derived from the results obtained in 1870. Mr. Buffham points out that,
+if this is admitted, then the plane of the planet's equator is not
+coincident with the plane of the orbits of the satellites. Nor need we
+be surprised at this departure from the general rule, where such an
+anomalous inclination exists. In singular confirmation of this is Mr.
+Lassell's observation of 1862, Jan. 29, where he says: "I received an
+impression which I am unable to render certain of an equatorial dark
+belt, and of an ellipticity of form."
+
+Some observations made in 1872-3 with the great six-foot reflector of
+Lord Rosse may here be briefly referred to. A number of measures, both
+of position and distance, of Oberon and Titania, were made, [1] and a
+few of Umbriel and Ariel, but "the shortness of the time available (40
+minutes) each night for the observation of the planet with the six-foot
+instrument, the atmospheric disturbance, so often a source of annoyance
+in using so large an aperture, and other unfavorable circumstances,
+tended to affect the value of the observations, and to make the two
+inner satellites rarely within detection."
+
+[Footnote 1: "Monthly Notices R. A. S.," March, 1875.]
+
+On Feb. 10, 1872, Lord Rosse notes that all four satellites were seen on
+the same side of the planet. On Jan. 16, 1873, when definition was good,
+no traces of any markings were seen. Diameter of Uranus = 5.29". Power
+414 was usually employed, though at times the inner satellites could be
+more satisfactorily seen with 625.
+
+It may be mentioned as an interesting point that, some fifty years
+after the first discovery of Uranus by Herschel, it was accidentally
+rediscovered by his son, Sir John Herschel, who recognized it by
+its disk, and had no idea as to the identity of the object until an
+ephemeris was referred to. Sir John mentions the fact as follows, in a
+letter to Admiral Smyth, written in 1830, August 8:
+
+"I have just completed two twenty-foot reflectors, and have got some
+interesting observations of the satellites of Uranus. The first sweep
+I made with my new mirror I _re-discovered_ this planet by its _disk_,
+having blundered upon it by the merest accident for 19 Capricorni."
+
+In commenting upon the centenary of an important scientific discovery we
+are naturally attracted to inquire what progress has been made in the
+same field during the comparatively short interval of one hundred years
+which has elapsed since it occurred. We have called it a short interval,
+because it cannot be considered otherwise from an astronomical or
+geological point of view, though, as far as human life is concerned,
+it can only be regarded as a very lengthy period, including several
+generations within its limits.
+
+Since Herschel, in 1781, discovered Uranus, astronomy has progressed
+with great rapidity, so that it would be impossible to enumerate in a
+brief memoir the many additional discoveries which have resulted from
+assiduous observation. A century ago only five planets were known
+(excluding the Earth), now we are acquainted with about two hundred and
+thirty of these bodies; and one of these, found in 1846, is a large
+planet whose orbit lies exterior to that of Uranus. In fact, the state
+of astronomical knowledge a century ago has undergone wonderful changes.
+It has been rendered far more complete and comprehensive by the
+diligence of its adherents and by the unwearying energy with which both
+in theory and practice it has been pursued. A zone of small planets has
+been discovered between Mars and Jupiter just where the analogies of the
+planetary distances indicated the probable existence of a large planet.
+The far-off Neptune was revealed in 1846 by a process of analytical
+reasoning as unique as it was triumphant, and which proved how well
+the theory of planetary perturbations was understood. The planet was
+discovered by calculation, its position in the heavens assigned, and the
+telescope was then employed merely as the instrument of its detection.
+The number of satellites which a century ago numbered only ten has now
+reached twenty, and the discovery in 1877 of two moons accompanying Mars
+shows that the work is being continued with marked success.
+
+In other departments we also find similar evidence of increasing
+knowledge. The periodicity of the sun spots, the existence of systems of
+binary stars, meteor showers, and their affinity with cometary orbits
+may be mentioned as among the more important, while a host of new
+comets, chiefly telescopic, have been detected. Large numbers of nebulae
+and double stars have been catalogued, and we have evidence every year
+of the activity with which these several branches are being followed up.
+
+In fine, it matters little to what particular department of astronomical
+investigation we look for traces of advancement during the past hundred
+years, for it is evident throughout them all, and sufficiently proves
+that the interest formerly taken in the science has not only been well
+sustained but has become more general and popular, and is extending its
+attractive features to all classes of the community.
+
+In Herschel's day large telescopes were rare. A man devoting himself to
+the study of the heavenly bodies as a means of intellectual recreation
+was considered a phenomenon, and indeed that appellation might be
+fittingly applied to the few isolated individuals who really occupied
+themselves in such work. How different is the case now that the pleasant
+ways of science have called so many to her side and so far perfected her
+means of research as to make them accessible to all who care to see and
+investigate for themselves the unique and wonderful truths so easily
+within reach! Large telescopes have become common enough, and there is
+no lack of hands and eyes to utilize them, nor of understanding, ever
+ready to appreciate, in sincerity and humbleness, those objects which
+display in an eminent degree the all-wise conceptions of a great
+Creator! It is, therefore, a most gratifying sign to notice this rapid
+development of astronomy, and to see year by year the increasing number
+of its advocates and the record of many new facts gleaned by vigorous
+observation.
+
+The character of recent discoveries distinctly intimates that, in future
+years, some departments of the science will become very complicated,
+owing to the necessity of dealing with a large number of minute bodies,
+for the tendency of modern researches has been to reveal objects which
+by their faintness had hitherto eluded detection. And when we consider
+that these bodies are rapidly increasing year by year, the idea is
+obviously suggested that, inasmuch as their numbers are comparatively
+illimitable, and there is likely to be no immediate abatement in the
+enthusiasm of observers, difficulties will arise in identifying them
+apart and forming them into catalogues with their orbital elements
+attached, so that the individual members may be redetected at any time.
+
+In this connection we allude particularly to minor planets, to
+telescopic comets, and to meteoric streams, which severally form a very
+numerous group of bodies of which the known members are accumulating to
+a great extent. As complications arise, some remedies must be applied to
+their solution, and one probable effect will be that astronomers will be
+induced each one to have a specialty or branch to which his energies are
+mainly directed. The science will become so wide in its application and
+so intricate in its details that it will become more than ever necessary
+for observers to select or single out definite lines of investigation
+and pursue them closely, for success is far more likely to attend such
+exertions than those which are not devoted to any special end, but
+employed rather in a general survey of phenomena.
+
+We have already before us some excellent instances in which individual
+energies have been aptly utilized in the prosecution of original work
+in some specific branch of astronomy, and we are strongly disposed to
+recommend such exclusive labors to those who have the means and the
+desire to achieve something useful. Observers who find one subject
+monotonous and then take up another for the sake of variation are not
+likely to get far advanced in either. In the case of amateurs who use a
+telescope merely for amusement, and indiscriminately apply it to nearly
+every conspicuous object in the firmament without any particular purpose
+other than to satisfy their curiosity, the matter is somewhat different,
+and our remarks are not applicable to them. We refer more pointedly
+to those who have a regard for the interests of the science and whose
+enthusiasm enables them to work habitually and with some pertinacity.
+
+History tells us that the Great Alexander wept when he found he had no
+other worlds to conquer, and we fear that some astronomers will lament
+that they have little prospect of discovering anything fresh in a sphere
+to which our giant telescopes have been so often directed, but this is
+founded on a palpable misconception. Certain objects, such as comets for
+example, do not require great power, and the revelation of new meteor
+showers is entirely a question for the naked eye. In fact, it may be
+confidently asserted that observations undertaken with energy and
+persistency will, if rightly directed, more than compensate for defects
+of instrumental power.
+
+It is true, however, that in certain quarters we must look to large
+instruments alone for new discoveries. It would be useless searching for
+an ultra-Neptunian planet, or for additional satellites to Uranus or
+Neptune, or for the materials to determine the rotation periods of these
+planets with a small telescope. Every observer will find objects suited
+to the capacity of his instrument, and he may not only employ it
+usefully but possibly make a discovery of nearly equal import with that
+which rendered the name of Herschel famous a century ago.--_Popular
+Science Review_.
+
+       *       *       *       *       *
+
+
+
+
+THE VARYING SUSCEPTIBILITY OF PLANTS AND ANIMALS TO POISONS AND
+DISEASES.
+
+
+Much attention is being devoted to the causes which determine the
+aptitude or immunity with animals for maladies. This is in a general
+sense called medical geography, as a physician who has prescribed for
+patients in various parts of the world, and belonging to different
+races--the white, yellow, and black--has been able to note the
+diversities in the same disease, and the contradictions in the remedies
+employed.
+
+The true social peril, hardly discovered before we became aware how
+to conjure it, lies in those legions of animalcules or microbes that
+surround us and in the middle of which we live. M. Pasteur has revealed
+them to us as the factors in infectious diseases. Claude Bernard
+has demonstrated the community which exists between animals and
+vegetables--phenomena of movement, of sensibility, of production of
+heat, of respiration, of digestion even, for there are the _Drosera_ and
+kindred carnivorous plants. Iron cures chlorosis in vegetables as well
+as in animals, and chloroform and ether render both insensible. There
+resemblances are more striking still between animals. After Baudrimont,
+insects are, in presence of alcohols, chloroform, and irrespirable
+gases, similarly affected as man. Many maladies, too, are common to
+man and several species of animals; and this organic identity is best
+illustrated in the relationship between epidemics and epizootias,
+cancer, asthma, phthisis, smallpox, rabies, glanders, charbon, etc.,
+afflict alike man and many species of animals.
+
+The differences between races are not less remarkable--odor and taste,
+for example. According to anthropophagy, negroes are best, and white
+people most detestable. Broca remarked, that, in the dissecting room,
+the muscles of the negro putrefied less rapidly than those of whites. It
+is perhaps to these anatomical differences that the diverse action of
+the same poison, in the case of races or species, may be attributed. On
+certain rodentia belladonna exercises no influence; morphine for a horse
+is a violent stimulant; a snail remains insensible to digitalis; goats
+eat tobacco with impunity; and in the Tarentin the inhabitants rear only
+black sheep, because a plant abounds which is noxious for white sheep.
+
+The nature of these conditions is a mystery for science. The _Solanae_
+tribe of plants furnish a principle which, as its name implies, produces
+consolation or forgetfulness, by acting on the tissues of the brain
+where resides the organ of thought; now, on the authority of Professor
+Bouchardat, these opiates have the less of effect in proportion as the
+animals possess the less of intelligence.
+
+To the same anatomical peculiarities must be ascribed the choice that
+disease makes in such or such a race. Glanders, for instance, so
+virulent with the horse, the ass, and man, produce in the case of the
+dog only a local accident; peripneumonia, so contagious among horned
+cattle, is more benign in its action on Dutch than other breeds of
+stock; the cattle plague that decimates so many farms is communicated by
+cattle to each other from the slightest contact, while the closest and
+most constant association is necessary to communicate the disease
+to sheep, and even when they are affected its action is not severe.
+Further, that plague only attacks ruminant animals--oxen, goats, sheep,
+zebras, gazelles, etc. Ten years ago this plague broke out in the Jardin
+d'Acclimatation; not a ruminant escaped, and also one animal not of that
+class, a little tenant nearly related to the pig--the _peccari_.
+
+Now, Dr. Condereau has demonstrated recently that the stomach of the pig
+has a rudimentary organization recalling that of the ruminants. Clearly,
+the stomach of the peccari, and perhaps that of the pig, present a
+favorable medium for the parasitical microbe peculiar to the rinderpest.
+In the potato disease, again, all the varieties are not affected with
+the same degree of violence; it is more marked in its action on the
+round yellows than the reds, and on the latter rather than the pink. But
+the symptoms even of the same malady differ, the parasite's attacks on
+the tissues being dissimilar. Oak galls are produced from the prickings
+of insects; now around the same larva often four varieties of galls are
+recognized. In the case of consumption in cattle, the disease marches
+slowly; in that of pigs it takes the galloping form, as with man.
+
+Each people or nation has its peculiar pathology and also its peculiar
+cures. A negro can take a dose of tartar ten times more excessive than a
+white; the same dose of brandy given to a black, a yellow, and a white,
+will not produce on the three men either drunkenness at the same moment,
+or intoxication at all. Mulattoes can sustain more drastic aperients
+than other races; the negro does not suffer from yellow fever, but he
+readily falls to phthisis; he will catch the cholera more quickly than a
+white. Human races, where they may catch the same intermittent fever at
+the identical moment and in the same swamp, will not the less display
+different types of fever. Dr. Crevaux has shown that a certain insect
+with the North American Indian is not the same as with the negro or the
+maroon, and both differ from that peculiar to Europeans.
+
+M. Pasteur's beautiful experiments have conclusively demonstrated that
+fowls do not catch the _charbon_; now the vital warmth of birds is from
+seven to nine degrees higher than in the case of mammiferous animals;
+he imagined that if the fowl was cooled down by baths to the lower
+temperature, it would be liable equally to become affected; he tried,
+and the result proved he was correct.
+
+The absence, then, of a certain temperature would be the reason why
+birds are exempt. The microbes are the agents of infectious disease;
+when these swarm in the blood of an individual they seem to leave there
+something pernicious for parasites resembling themselves, or to bring
+away with them something necessary to the life of their successors. A
+glass of sugar and water, where leaven has already fermented and yielded
+alcohol, is incapable of producing a second crop of leaven; similarly
+the blood of an individual, once contaminated, becomes uninhabitable
+afterward for like microbes. The individual has acquired immunity. Such
+is the principle of vaccination.--_Paris Correspondent of the Kansas
+City Review_.
+
+       *       *       *       *       *
+
+
+
+
+KIND TREATMENT OF HORSES.
+
+
+It has been observed by experienced horse trainers that naturally
+vicious horses are rare, and that among those that are properly trained
+and kindly treated when colts they are the exception.
+
+It is superfluous to say that a gentle and docile horse is always the
+more valuable, other qualities being equal, and it is almost obvious
+that gentle treatment tends to develop this admirable quality in the
+horse as well as in the human species, while harsh treatment has the
+contrary tendency. Horses have been trained so as to be entirely
+governed by the words of his driver, and they will obey and perform
+their simple but important duties with as much alacrity as the child
+obeys the direction of the parent.
+
+It is true that all horses are not equally intelligent and tractable,
+but it is probable that there is less difference among them in this
+regard than there is among his human masters, since there are many
+incitements and ambitions among men that do not affect animals.
+
+The horse learns to know and to have confidence in a gentle driver, and
+soon discovers how to secure for himself that which he desires, and
+to understand his surroundings and his duties. The tone, volume, and
+inflection of his master's voice indicate much, perhaps more than the
+words that are spoken. Soothing tones rather than words calm him if
+excited by fear or anger, and angry and excited tones tend to excite or
+anger him. In short, bad masters make bad horses.
+
+       *       *       *       *       *
+
+A catalogue, containing brief notices of many important scientific
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