The Project Gutenberg EBook of Scientific American Supplement, No. 620, November 19,1887, by Various This eBook is for the use of anyone anywhere at no cost and with almost no restrictions whatsoever. You may copy it, give it away or re-use it under the terms of the Project Gutenberg License included with this eBook or online at www.gutenberg.org Title: Scientific American Supplement, No. 620, November 19,1887 Author: Various Release Date: July 24, 2005 [EBook #16354] Language: English Character set encoding: ISO-8859-1 *** START OF THIS PROJECT GUTENBERG EBOOK SCIENTIFIC AMERICAN *** Produced by Juliet Sutherland and the Online Distributed Proofreading Team at www.pgdp.net SCIENTIFIC AMERICAN SUPPLEMENT NO. 620 NEW YORK, NOVEMBER 19, 1887 Scientific American Supplement. Vol. XXIV., No. 620. Scientific American established 1845 Scientific American Supplement, $5 a year. Scientific American and Supplement, $7 a year. TABLE OF CONTENTS. I. ARCHITECTURE—Bristol Cathedral—The history and description of this ancient building, with large illustration.—1 illustration. 9904 II. BIOGRAPHY—Oliver Evans and the Steam Engine.—The work of this early pioneer, hitherto but slightly recognized at his true worth as an inventor. 9896 III. CHEMISTRY—The Chemistry of the Cotton Fiber—By Dr. BOWMAN—An interesting investigation, showing the variation in composition in different cottons. 9909 Synthesis of Styrolene. 9910 Notes on Saccharin. 9910 Alcohol and Turpentine. 9910 IV. ENGINEERING—Auguste's Endless Stone Saw—A valuable improvement, introducing the principle of the band saw, and producing a horizontal cut—10 illustrations. 9896 V. ELECTRICITY.—A Current Meter—The Jehl & Rupp meter for electricity described—1 illustration. 9903 Mix & Genest's Microphone Telephone—The new telephone recently adopted by the imperial post office department of Germany—3 illustrations. 9902 Storage Batteries for Electric Locomotion—By A. RECKENZAUN—A valuable paper on this subject, giving historical facts and working figures of expense, etc. 9903 The Telemeter System—By R.F. UPTON—The system of Ö.L. Clarke, of New York, as described before the British Association—A valuable tribute to an American inventor—1 illustration. 9900 VI. METALLURGY.—The Newbery-Vautin Chlorination Process—A new process of extracting gold from its ores, with details of the management of the process and apparatus—1 illustration. 9907 VII. MISCELLANEOUS.—A Gigantic Load of Lumber—The largest barge load of lumber ever shipped—The barge Wahnapitæ and her appearance as loaded at Duluth—1 illustration. 9907 Apparatus for Exercising the Muscles—An appliance for use by invalids requiring to exercise atrophied limbs—1 illustration. 9908 Practical Education.—A plea for the support of manual training schools. 9906 Waves—The subject of ocean waves fully treated—An interesting resume of our present knowledge of this phenomenon of fluids. 9906 VIII. NAVAL ENGINEERING—The New Spanish Armored Cruiser Reina Regente. — Illustration and full description of this recent addition to the Spanish navy.—1 illustration. 9895 The Spanish Torpedo Boat Azor—Illustration and note of speed, etc., of this new vessel—1 illustration. 9895 IX. OPHTHALMOLOGY—The Bull Optometer—An apparatus for testing the eyesight.—The invention of Dr George J. Bull.—3 illustrations. 9908 X. SANITATION AND HYGIENE—The Sanitation of Towns—By J. GORDON, C.E.—A presidential address before the Leicester meeting of the Society of Municipal and Sanitary Engineers and Surveyors of England. 9909 XI. TECHNOLOGY—A New Monster Revolving Black Ash Furnace and the Work Done with It—By WATSON SMITH—The great furnace of the Widnes Alkali Company described, with results and features of its working—4 illustrations. 9900 Apparatus Used for Making Alcohol for Hospital Use during the Civil War between the States—By CHARLES K. GALLAGHER—A curiosity of war times described and illustrated.—1 illustration. 9900 Confederate Apparatus for Manufacturing Saltpeter for Ammunition —By CHARLES K. GALLAGHER—Primitive process for extracting saltpeter from earth and other material—1 illustration. 9900 Electrolysis and Refining of Sugar—A method of bleaching sugar said to be due to ozone produced by electric currents acting on the solution—1 illustration. 9903 Improvements in the Manufacture of Portland Cement—By FREDERICK RANSOME, A.I.C.E.—An important paper recently read before the British Association, giving the last and most advanced methods of manufacture. 9901 Roburite, the New Explosive—Practical tests of this substance, with special application to coal mining. 9897 The Mechanical Reeling of Silk.—An advanced method of treating silk cocoons, designed to dispense with the old hand winding of the raw silk.—3 illustrations. 9898 THE SPANISH TORPEDO BOAT AZOR. THE SPANISH TORPEDO BOAT AZOR. The Azor was built by Yarrow & Co., London, is of the larger class, having a displacement of 120 tons, and is one of the fastest boats afloat. Her speed is 24½ miles per hour. She has two tubes for launching torpedoes and three rapid firing Nordenfelt guns. She lately arrived in Santander, Spain, after the very rapid passage of forty hours from England. THE NEW SPANISH ARMORED CRUISER REINA REGENTE. THE NEW SPANISH ARMORED CRUISER REINA REGENTE. The new armored cruiser Reina Regente, which has been built and engined by Messrs. James & George Thomson, of Clydebank, for the Spanish government, has recently completed her official speed trials on the Clyde, the results attained being sufficient to justify the statement made on her behalf that she is the fastest war cruiser in the world. She is a vessel of considerable size, the following being her measurements: Length over all, 330 ft., and 307 ft. between perpendiculars; breadth, 50½ ft.; and her draught is 20 ft., giving a displacement of 5,000 tons, which will be increased to 5,600 tons when she is fully equipped. This vessel belongs to the internally protected type of war cruisers, a type of recent origin, and of which she is the largest example yet built. The internal protection includes an armored deck which consists of steel plates ranging from 3-1/8 in. in thickness in the flat center to 4¾ in. at the sloping sides of the deck. This protective deck covers the "vitals" of the ship, the machinery, boilers, etc. Then there is a very minute subdivision in the hull of the ship, there being, in all, 156 water-tight compartments, 83 of which are between the armored deck and the one immediately above it, or between wind and water. Most of these compartments are used as coal bunkers. Of the remainder of the water-tight compartments, 60 are beneath the armor. Throughout her whole length the Reina Regente has a double bottom, which also extends from side to side of the ship. In order to keep the vessel as free of water as possible, there have been fitted on board four 14 in. centrifugal pumps, all of which are connected to a main pipe running right fore and aft in the ship, and into which branches are received from every compartment. These pumps are of the "Bon Accord" type, and were supplied by Messrs. Drysdale & Co., Glasgow. Not being weighted by massive external armor, the Reina Regente is unusually light in proportion to her bulk, and in consequence it has been rendered possible to supply her with engines of extraordinary power. They are of the horizontal triple expansion type, driving twin screws, and placed in separate water-tight compartments. The boilers, four in number, are also in separate compartments. Well above the water line there are two auxiliary boilers, which were supplied by Messrs. Merryweather, London, and are intended for raising steam rapidly in cases of emergency. These boilers are connected with all the auxiliary engines of the ship, numbering no fewer than forty-three. The engines have been designed to indicate 12,000 horse power, and on the trial, when they were making 110 revolutions per minute, they indicated considerably upward of 11,000 horse power, the bearings all the while keeping wonderfully cool, and the temperature of the engine and boiler rooms being never excessive. The boilers are fitted with a forced draught arrangement giving a pressure of 1 in. of water. In the official run she attained a speed equal to 21 knots (over 24 miles) per hour, and over a period of four hours an average speed of 20.72 knots per hour was developed, without the full power of the engines being attained. The average steam pressure in the boilers was 140 lb. per square inch. In the course of some private trials made by the builders, the consumption of coal was tested, with the result that while the vessel was going at a moderate speed the very low consumption of 14 lb. of coal per indicated horse power per hour was reached. The vessel is capable of steaming 6,000 knots when there is a normal supply of coal in her bunkers, and when they are full there is sufficient to enable her to steam 13,000 knots. The Reina Regente will be manned by 50 officers and a crew of 350 men, all of whom will have their quarters on the main deck. Among her fittings and equipment there are three steam lifeboats and eight other boats, five of Sir William Thomson's patent compasses, and a complete electric light installation, the latter including two powerful search lights, which are placed on the bridge. All parts of the vessel are in communication by means of speaking tubes. In order to enable the vessel to turn speedily, she is fitted with the sternway rudder of Messrs. Thomson & Biles. This contrivance is a combination of a partially balanced rudder with a rudder formed as a continuation of the after lines of a ship. The partial balance tends to reduce the strains on the steering gear, and thereby enables the rudder area to be increased without unduly straining the gear. When fitted out for actual service, this novel war cruiser will have a most formidable armament, consisting of four 24 centimeter Hontorio guns (each of 21 tons), six 12 centimeter guns (also of the Hontorio type), six 6 pounder Nordenfelt guns, fourteen small guns, and five torpedo tubes—one at the stern, two amidships, and two at the bow of the ship. It is worthy of note that this war cruiser was constructed in fifteen months, or three months under the stipulated contract time; in fact, the official trial of the vessel took place exactly eighteen months from the signing of the contract. Not only is this the fastest war cruiser afloat, but her owners also possess in the El Destructor what is probably the simplest torpedo catcher afloat, a vessel which has attained a speed of 22½ knots, or over 26 miles, per hour.—Engineering. OLIVER EVANS AND THE STEAM ENGINE. A correspondent of the New York Times, deeming that far too much credit has been given to foreigners for the practical development of the steam engine, contributes the following interesting resume: Of all the inventions of ancient or modern times none have more importantly and beneficently influenced the affairs of mankind than the double acting high pressure steam engine, the locomotive, the steam railway system, and the steamboat, all of which inventions are of American origin. The first three are directly and the last indirectly associated with a patent that was granted by the State of Maryland, in 1787, being the very year of the framing of the Constitution of the United States. In view of the momentous nature of the services which these four inventions have rendered to the material and national interests of the people of the United States, it is to be hoped that neither they nor their origin will be forgotten in the coming celebration of the centennial of the framing of the Constitution. The high pressure steam engine in its stationary form is almost ubiquitous in America. In all great iron and steel works, in all factories, in all plants for lighting cities with electricity, in brief, wherever in the United States great power in compact form is wanted, there will be found the high pressure steam engine furnishing all the power that is required, and more, too, if more is demanded, because it appears to be equal to every human requisition. But go beyond America. Go to Great Britain, and the American steam engine—although it is not termed American in Great Britain—will be found fast superseding the English engine—in other words, James Watt's condensing engine. It is the same the world over. On all the earth there is not a steam locomotive that could turn a wheel but for the fact that, in common with every locomotive from the earliest introduction of that invention, it is simply the American steam engine put on wheels, and it was first put on wheels by its American inventor, Oliver Evans, being the same Oliver Evans to whom the State of Maryland granted the before mentioned patent of 1787. He is the same Oliver Evans whom Elijah Galloway, the British writer on the steam engine, compared with James Watt as to the authorship of the locomotive, or rather "steam carriage," as the locomotive was in those days termed. After showing the unfitness of Mr. Watt's low pressure steam engine for locomotive purposes, Mr. Galloway, more than fifty years ago, wrote: "We have made these remarks in this place in order to set at rest the title of Mr. Watt to the invention of steam carriages. And, taking for our rule that the party who first attempted them in practice by mechanical arrangements of his own is entitled to the reputation of being their inventor, Mr. Oliver Evans, of America, appears to us to be the person to whom that honor is due." He is the same Oliver Evans whom the Mechanics' Magazine, of London, the leading journal of its kind at that period, had in mind when, in its number of September, 1830, it published the official report of the competitive trial between the steam carriages Rocket, San Pariel, Novelty, and others on the Liverpool and Manchester Railway. In that trial the company's engines developed about 15 miles in an hour, and spurts of still higher speed. The Magazine points to the results of the trial, and then, under the heading of "The First Projector of Steam Traveling," it declares that all that had been accomplished had been anticipated and its feasibility practically exemplified over a quarter of a century before by Oliver Evans, an American citizen. The Magazine showed that many years before the trial Mr. Evans had offered to furnish steam carriages that, on level railways, should run at the rate of 300 miles in a day, or he would not ask pay therefor. The writer will state that this offer by Mr. Evans was made in November, 1812, at which date not a British steam carriage had yet accomplished seven miles in an hour. In 1809 Mr. Evans endeavored to establish a steam railway both for freight and passenger traffic between New York and Philadelphia, offering to invest $500 per mile in the enterprise. At the date of his effort there was not a railway in the world over ten miles long, nor does there appear to have been another human being who up to that date had entertained even the thought of a steam railway for passenger and freight traffic. In view of all this, is it at all surprising that the British Mechanics' Magazine declared Oliver Evans, an American, to be the first projector of steam railway traveling? In 1804 Mr. Evans made a most noteworthy demonstration, his object being to practically exemplify that locomotion could be imparted by his high pressure steam engine to both carriages and boats, and the reader will see that the date of the demonstration was three years before Fulton moved a boat by means of Watt's low pressure steam engine. The machine used involved the original double acting high pressure steam engine, the original steam locomotive, and the original high pressure steamboat. The whole mass weighed over twenty tons. Notwithstanding there was no railway, except a temporary one laid over a slough in the path, Mr. Evans' engine moved this great weight with ease from the southeast corner of Ninth and Market streets, in the city of Philadelphia, one and a half miles, to the River Schuylkill. There the machine was launched into the river, and the land wheels being taken off and a paddle wheel attached to the stern and connected with the engine, the now steamboat sped away down the river until it emptied into the Delaware, whence it turned upward until it reached Philadelphia. Although this strange craft was square both at bow and stern, it nevertheless passed all the up-bound ships and other sailing vessels in the river, the wind being to them ahead. The writer repeats that this thorough demonstration by Oliver Evans of the possibility of navigation by steam was made three years before Fulton. But for more than a quarter of a century prior to this demonstration Mr. Evans had time and again asserted that vessels could be thus navigated. He did not contend with John Fitch, but on the contrary tried to aid him and advised him to use other means than oars to propel his boat. But Fitch was wedded to his own methods. In 1805 Mr. Evans published a book on the steam engine, mainly devoted to his form thereof. In this book he gives directions how to propel boats by means of his engine against the current of the Mississippi. Prior to this publication he associated himself with some citizens of Kentucky— one of whom was the grandfather of the present Gen. Chauncey McKeever, United States Army—the purpose being to build a steamboat to run on the Mississippi. The boat was actually built in Kentucky and floated to New Orleans. The engine was actually built in Philadelphia by Mr. Evans and sent to New Orleans, but before the engine arrived out the boat was destroyed by fire or hurricane. The engine was then put to sawing timber, and it operated so successfully that Mr. Stackhouse, the engineer who went out with it, reported on his return from the South that for the 13 months prior to his leaving the engine had been constantly at work, not having lost a single day! The reader can thus see the high stage of efficiency which Oliver Evans had imparted to his engine full 80 years ago. On this point Dr. Ernst Alban, the German writer on the steam engine, when speaking of the high pressure steam engine, writes: "Indeed, to such perfection did he [Evans] bring it, that Trevithick and Vivian, who came after him, followed but clumsily in his wake, and do not deserve the title of either inventors or improvers of the high pressure engine, which the English are so anxious to award to them.... When it is considered under what unfavorable circumstances Oliver Evans worked, his merit must be much enhanced; and all attempts made to lessen his fame only show that he is neither understood nor equaled by his detractors." The writer has already shown that there are bright exceptions to this general charge brought by Dr. Alban against British writers, but the overwhelming mass of them have acted more like envious children than like men when speaking of the authorship of the double acting high pressure steam engine, the locomotive, and the steam railway system. Speaking of this class of British writers, Prof. Renwick, when alluding to their treatment of Oliver Evans, writes: "Conflicting national pride comes in aid of individual jealousy, and the writers of one nation often claim for their own vain and inefficient projectors the honors due to the successful enterprise of a foreigner." Many of these writers totally ignore the very existence of Oliver Evans, and all of them attribute to Trevithick and Vivian the authorship of the high pressure steam engine and the locomotive. Yet, when doing so, all of them substantially acknowledge the American origin of both inventions, because it is morally certain that Trevithick and Vivian got possession of the plans and specifications of his engine. Oliver Evans sent them to England in 1794-5 by Mr. Joseph Stacy Sampson, of Boston, with the hope that some British engineer would approve and conjointly with him take out patents for the inventions. Mr. Sampson died in England, but not until after he had extensively exhibited Mr. Evans' plans, apparently, however, without success. After Mr. Sampson's death Trevithick and Vivian took out a patent for a high pressure steam engine. This could happen and yet the invention be original with them. But they introduced into Cornwall a form of boiler hitherto unknown in Great Britain, namely, the cylindrical flue boiler, which Oliver Evans had invented and used in America years before the names of Trevithick and Vivian were associated with the steam engine. Hence, they were charged over fifty years ago with having stolen the invention of Mr. Evans, and the charge has never been refuted. Hence when British writers ignore the just claims of Oliver Evans and assert for Trevithick and Vivian the authorship of the high pressure steam engine and the locomotive, they thereby substantially acknowledge the American origin of both inventions. They are not only of American origin, but their author, although born in 1755, was nevertheless an American of the second generation, seeing that he was descended from the Rev. Dr. Evans Evans, who in the earlier days of the colony of Pennsylvania came out to take charge of the affairs of the Episcopal Church in Pennsylvania. The writer has thus shown that with the patent granted by the State of Maryland to Oliver Evans in 1787 were associated—first, the double acting high pressure steam engine, which to-day is the standard steam engine of the world; second, the locomotive, that is in worldwide use; third, the steam railway system, which pervades the world; fourth, the high pressure steamboat, which term embraces all the great ocean steamships that are actuated by the compound steam engine, as well as all the steamships on the Mississippi and its branches. The time and opportunity has now arrived to assert before all the world the American origin of these universally beneficent inventions. Such a demonstration should be made, if only for the instruction of the rising generation. Not a school book has fallen into the hands of the writer that correctly sets forth the origin of the subject matter of this paper. He apprehends that it is the same with the books used in colleges and universities, for otherwise how could that parody on the history of the locomotive, called "The Life of George Stephenson, Railway Engineer," by Samuel Smiles, have met such unbounded success? To the amazement of the writer, a learned professor in one of the most important institutions of learning in the country did, in a lecture, quote Smiles as authority on a point bearing on the history of the locomotive! It is true that he made amends by adding, when his lecture was published, a counter statement; but that such a man should have seriously cited such a work shows the widespread mischief done among people not versed in engineering lore by the admirably written romance of Smiles, who as Edward C. Knight, in his Mechanical Dictionary, truly declares, has "pettifogged the whole case." If, as Prof. Renwick intimates, "conflicting national pride" has led the major part of British writers to suppress the truth as to the origin of the high pressure steam engine, the locomotive, and the steam railway system, surely true national pride should induce the countrymen of Oliver Evans to assert it. In closing this paper the writer will say, for the information of the so-called "practical" men of the country, or, in other words, those men whose judgment of an invention is mainly guided by its money value, that Poor's Manual of Railroads in the United States for 1886 puts their capital stock and their debts at over $8,162,000,000. The value of the steamships and steamboats actuated by the high pressure steam engine the writer has no means of ascertaining. Neither can he appraise the factories and other plants in the United States—to say nothing of the rest of the world—in which the high pressure steam engine forms the motive power. AUGUSTE'S ENDLESS STONE SAW. It does not seem as if the band or endless saw should render the same services in sawing stone as in working wood and metals, for the reason that quite a great stress is necessary to cause the advance of the stone (which is in most cases very heavy) against the blade. Mr. A. Auguste, however, has not stopped at such a consideration, or, better, he has got round the difficulty by holding the block stationary and making the blade act horizontally. Fig. 1 gives a general view of the apparatus; Fig. 2 gives a plan view; Fig. 3 is a transverse section; Fig. 4 is an end view; Figs. 5, 6, and 7 show details of the water and sand distributer; and Figs. 8, 9, and 10 show the pulleys arranged for obtaining several slabs at once. FIG. 1 AUGUSTE'S STONE SAW. FIG. 2 AUGUSTE'S STONE SAW. FIGS. 3 and 4 AUGUSTE'S STONE SAW. FIGS. 5 through 10 AUGUSTE'S STONE SAW. The machine is wholly of cast iron. The frame consists of four columns, A, bolted to a rectangular bed plate, A', and connected above by a frame, B, that forms a table for the support of the transmission pieces, as well as the iron ladders, a, and the platform, b, that supports the water reservoirs, C, and sand receptacles, C'. Between the two columns at the ends of the machine there are two crosspieces, D and D', so arranged that they can move vertically, like carriages. These pieces carry the axles of the pulleys, P and P', around which the band saw, S, passes. In the center of the bed plate, A', which is cast in two pieces connected by bolts, there are ties to which are screwed iron rails, e, which form a railway over which the platform car, E, carrying the stone is made to advance beneath the saw. The saw consists of an endless band of steel, either smooth or provided with teeth that are spaced according to the nature of the material to be worked. It passes around the pulleys, P and P', which are each encircled by a wide and stout band of rubber to cause the blade to adhere, and which are likewise provided with two flanges. Of the latter, the upper one is cast in a piece with the pulley, and the lower one is formed of sections of a circle connected by screws. The pulley, P, is fast, and carries along the saw; the other, P', is loose, and its hub is provided with a bronze socket (Figs. 1 and 4). It is through this second pulley that the blade is given the desired tension, and to this effect its axle is forged with a small disk adjusted in a frame and traversed by a screw, d', which is maneuvered through a hand wheel. The extremities of the crosspieces, D and D', are provided with brass sockets through which the pieces slide up and down the columns, with slight friction, under the action of the vertical screws, g and g', within the columns. A rotary motion is communicated to the four screws simultaneously by the transmission arranged upon the frame. To this effect, the pulley, P, which receives the motion and transmits it to the saw, has its axle, f, prolonged, and grooved throughout its length in order that it may always be carried along, whatever be the place it occupies, by the hollow shaft, F, which is provided at the upper extremity with a bevel wheel and two keys placed at the level of the bronze collars of its support, G. The slider, D, is cast in a piece with the pillow block that supports the shaft, f, and the bronze bushing of this pillow block is arranged to receive a shoulder and an annular projection, both forged with the shaft and designed to carry it, as well as the pulley, P, keyed to its extremity. Now the latter, by its weight, exerts a pressure which determines a sensible friction upon the bushing through this shoulder and projection, and, in order to diminish the same, the bushing is continuously moistened with a solution of soap and water through the pipe, g, which runs from the reservoir, G'. The saw is kept from deviating from its course by movable guides placed on the sliders, D and D'. These guides, H and H', each consist of a cast iron box fixed by a nut to the extremity of the arms, h and h', and coupled by crosspieces, j and j', which keep them apart and give the guides the necessary rigidity. The shaft, m, mounted in pillow blocks fixed to the left extremity of the frame, receives motion from the motor through the pulley, p, at the side of which is mounted the loose pulley, p. This motion is transmitted by the drum, M, and the pulley, L, to the shaft, l, at the other extremity. This latter is provided with a pinion, l', which, through the wheel, F', gives motion to the saw. The shaft, m, likewise controls the upward or downward motion of the saw through the small drums, N and n, and the two pairs of fast and loose pulleys, N' and n'. This shaft, too, transmits motion (a very slow one) to the four screws, g and g', in the interior of the columns, and the nuts of which are affixed to the sliders, D and D'. To this effect, the shaft, q, is provided at its extremities with endless screws that gear with two wheels, q', with helicoidal teeth fixed near the middle of two parallel axes, r, running above the table, B, and terminating in bevel wheels, r', that engage with similar wheels fixed at the end of the screws, g and g'. The car that carries the block to the saw consists of a strong frame, E, mounted upon four wheels. This frame is provided with a pivot and a circular track for the reception of the cast iron platform, E', which rests thereon through the intermedium of rollers. Between the rails, e, and parallel with them, are fixed two strong screws, e', held by supports that raise them to the bottom of the car frame, so that they can be affixed thereto. When once the car is fastened in this way, the screws are revolved by means of winches, and the block is thus made to advance or recede a sufficient distance to make the lines marked on its surface come exactly opposite the saw blade. In sawing hard stones, it is necessary, as well known, to keep up a flow of water and fine sand upon the blade in order to increase its friction. Upon two platforms, b, at the extremities of the machine, are fixed the water reservoir, C, and the receptacles, C', containing fine sand or dry pulverized grit stone. As may be seen from Figs. 5 and 6, the bottom of the sand box, C', is conical and terminates in a hopper, T, beneath which is adjusted a slide valve, t, connected with a screw that carries a pulley, T'. By means of this valve, the bottom of the hopper may be opened or closed in such a way as to regulate the flow of the sand at will by acting upon the pulley, T', through a chain, t', passing over the guide pulley, t². A rubber tube, u, which starts from the hopper, runs into a metal pipe, U, that descends to the guide, H, with which it is connected by a collar. Under the latter, this pipe terminates in a sphere containing a small aperture to allow the sand to escape upon an inclined board provided with a flange. At the same time, through the rubber tube, c, coming from the reservoir, C, a stream of water is directed upon the board in order to wet the sand. As the apparatus with but a single endless saw makes but two kerfs at once, Mr. Auguste has devised an arrangement by means of which several blades may be used, and the work thus be expedited. Without changing the general arrangements, he replaces the pulleys, P and P', by two half drums, V and V' (Figs. 8, 9, and 10), which are each cast in a piece with the crosspieces, D² and D³, designed to replace D and D', and, like them, sliding up and down the columns, A, of the frame. Motion is transmitted to all the saw blades by a cog wheel, X, keyed to the vertical shaft, f, and gearing with small pinions, x, which are equally distant all around, and which themselves gear with similar pinions forming the radii of a succession of circles concentric with the first. All these pinions are mounted upon axles traversing bronze bearings within the drum, which, to this effect, is provided with slots. The axles of the pinions are prolonged in order to receive rollers, x', surrounded with rubber so as to facilitate, through friction, the motion of all the blades running between them. The other drum, V', is arranged in the same way, except that it is not cast in a piece with the carriage, D³, but is so adjusted to it that a tension may be exerted upon the blades by means of the screw, d, and its hand wheel. Through this combination, all the blades are carried along at once in opposite directions and at the same speed.—Publication Industrielle. ROBURITE, THE NEW EXPLOSIVE. A series of experiments of great interest and vital importance to colliery owners and all those engaged in mining coal has been carried out during the last ten days in the South Yorkshire coal field. The new mines regulation act provides that any explosible used in coal mines shall either be fired in a water cartridge or be of such a nature that it cannot inflame firedamp. This indeed is the problem which has puzzled many able chemists during the last few years, and which Dr. Roth, of Berlin, claims to have solved with his explosive "roburite." We recently gave a detailed account of trials carried out at the School of Military Engineering, Chatham, to test the safety and strength of roburite, as compared with gun cotton, dynamite, and blasting gelatine. The results were conclusive of the great power of the new explosive, and so far fully confirmed the reports of the able mining engineer and the chemical experts who had been sent to Germany to make full inquiries. These gentlemen had ample opportunity of seeing roburite used in the coal mines of Westphalia, and it was mainly upon their testimony that the patents for the British empire were acquired by the Roburite Explosive Company. It has, however, been deemed advisable to give practical proof to those who would have to use it, that roburite possesses all the high qualities claimed for it, and hence separate and independent trials have been arranged in such representative collieries as the Wharncliffe Silkstone, near Sheffield, Monk Bretton, near Barnsley, and, further north, in the Durham coal field, at Lord Londonderry's Seaham and Silksworth collieries. Mr. G.B. Walker, resident manager of the Wharncliffe Colliery Company, had gone to Germany as an independent observer—provided with a letter of introduction from the Under Secretary of State for Foreign Affairs—and had seen the director of the government mines at Saarbruck, who gave it as his opinion that, so far as his experience had gone, the new explosive was a most valuable invention. Mr. Walker was so impressed with the great advantages of roburite that he desired to introduce it into his own colliery, where he gladly arranged with the company to make the first coal mining experiments in this country. These were recently carried out in the Parkgate seam of the Wharncliffe Silkstone colliery, under the personal superintendence of the inventor, Dr. Roth, and in the presence of a number of colliery managers and other practical men. In all six shots were fired, five of which were for the purpose of winning coal, while the sixth was expressly arranged as a "blowout shot." The roburite—which resembles nothing so much as a common yellow sugar— is packed in cartridges of about 4½ in. in length and 1½ in. in diameter, each containing about 65 grammes (one-seventh of a pound) inclosed in a waterproof envelope. By dividing a cartridge, any desired strength of charge can be obtained. The first shot had a charge of 90 grammes (one-fifth of a pound) placed in a hole drilled to a depth of about 4 ft. 6 in., and 1¾ in. in diameter. All the safety lamps were carefully covered, so that complete darkness was produced, but there was no visible sign of an explosion in the shape of flame— not even a spark—only the dull, heavy report and the noise made by the displaced coal. A large quantity of coal was brought down, but it was considered by most of the practical men present to be rather too much broken. The second shot was fired with a single cartridge of 65 grammes, and this gave the same remarkable results as regards absence of flame, and, in each case, there were no noxious fumes perceivable, even the moment after the shot was fired. This reduced charge gave excellent results as regards coal winning, and one of the subsequent shots, with the same weight of roburite, produced from 10 to 11 tons of coal in almost a solid mass. It has been found that a fertile cause of accidents in coal mines is insufficient tamping, or "stemming," as it is called in Yorkshire. Therefore a hole was bored into a strong wall of coal, and a charge of 45 grammes inserted, and very slightly tamped, with the view of producing a flame if such were possible. This "blowout" shot is so termed from the fact of its being easier for the explosion to blow out the tamping, like the shot from a gun, than to split or displace the coal. The result was most successful, as there was no flash to relieve the utter darkness. The second set of experiments took place on October 24 last, in the Monk Bretton colliery, near Barnsley, of which Mr. W. Pepper, of Leeds, is owner. This gentleman determined to give the new explosive a fair and exhaustive trial, and the following programme was carried out in the presence of a very large gathering of gentlemen interested in coal mining. The chief inspector of mines for Yorkshire and Lincolnshire, Mr. F.N. Wardell, was also present, and the Roburite Explosives Company was represented by Lieut.-General Sir John Stokes, K.C.B., R.E., chairman, and several of the directors. 1. Surface Experiments.—A shot fired on the ground, exposed. This gave no perceptible flame (70 grammes of roburite was the charge in these experiments). 2. A shot fired on the ground, bedded in fine coal dust. No flame nor ignition of the coal dust was perceptible. 3. A shot fired suspended in a case into which gas was conducted, and the atmospheric air allowed to enter so as to form an explosive mixture. The gas was not fired. 4. A shot fired in a boiler flue 16 ft. by 2 ft. 8 in., placed horizontally, in which was a quantity of fine coal dust kept suspended in the air by the action of a fan. No flame nor ignition of the coal dust took place. 5. A shot fired as above, except that an explosive mixture of gas and air was flowing into the boiler tube in addition to the coal dust. That this mixture was firedamp was proved by the introduction of a safety lamp, the flame of which was elongated, showing what miners call the "blue cap." There was no explosion of the gas or sign of flames. 6. A shot of roburite fired in the boiler tube without any gas or suspended coal dust. The report was quite as loud as in the preceding case; indeed, to several present it seemed more distinct. 7. A shot of ½ lb. gunpowder was fired under the same condition as No. 5, i.e., in an explosive mixture of gas and air with coal dust. The result was most striking, and appeared to carry conviction of the great comparative safety of roburite to all present. Not only was there an unmistakable explosion of the firedamp, with very loud report, and a vivid sheet of flame, but the gas flowing into the far end of the boiler tube was ignited and remained burning until turned off. In the Pit.—1. A 2 in. hole was drilled 4 ft. 6 in. deep into coal, having a face 7 yards wide, fast at both ends, and holed under for a depth of 8 ft., end on, thickness of front of coal to be blown down 2 ft. 10 in., plus 9 in. of dirt. This represented a most difficult shot, having regard to the natural lines of cleavage of the coal—a "heavy job" as it was locally termed. The charge was 65 grammes of roburite, which brought down a large quantity of coal, not at all too small in size. No flame was perceptible, although all the lamps were carefully covered. 2. A 2 in. hole drilled 4 ft. 6 in. into the side of the coal about 10 in. from the top, fast ends not holed under, width of space 10 ft. This was purposely a "blowout" shot. The result was again most satisfactory, the charge exploding in perfect darkness. 3. A "breaking up" shot placed in the stone roof for "ripping," the hole being drilled at an angle of 35 deg. or 40 deg. This is intended to open a cavity in the perfectly smooth roof, the ripping being continued by means of the "lip" thus formed. The charge was 105 grammes (nearly 4 oz), and it brought down large quantities of stone. 4. A "ripping" shot in the stone roof, hole 4 ft. 6 in. deep, width of place 15 ft. with a "lip" of 2 ft. 6 in. This is a strong stone "bind," and very difficult to get down. The trial was most successful, a large heap of stone being brought down and more loosened. 5. A second "blowout" shot, under the conditions most likely to produce an accident in a fiery mine. A 2 in. hole, 4 ft. 6 in. deep, was drilled in the face of the coal near the roof, and charged with 105 grammes of roburite. A space of 6 in. or 8 in. was purposely left between the charge and the tamping. The hole was then strongly tamped for a distance of nearly 2 ft. The report was very loud, and a trumpet-shaped orifice was formed at the mouth of the hole, but no flame or spark could be perceived, nor was any inconvenience caused by the fumes, even the instant after the explosion. Further Experiments at Wharncliffe Colliery.—On Tuesday, October 25, some very interesting surface trials were arranged with great care by Mr. Walker. An old boiler flue was placed vertically, and closed at top by means of a removable wooden cover, the interior space being about 72 cubic feet. A temporary gasometer had been arranged at a suitable distance by means of a paraffin cask having a capacity of 6 cubic feet suspended inside a larger cask, and by this means the boiler was charged with a highly explosive mixture of gas and air in the proportion of 1 to 12. 1. A charge of gunpowder was placed in the closed end of a piece of gas pipe, and strongly tamped, so as to give the conditions most unfavorable to the ignition of the firedamp. It was, however, ignited, and a loud explosion produced, which blew off the wooden cover and filled the boiler tube with flame. 2. Under the same conditions as to firedamp, a charge of roburite was placed on a block of wood inside the boiler, totally unconfined except by a thin covering of coal dust. When exploded by electricity, as in the previous case, no flame was produced, nor was the firedamp ignited. 3. The preceding experiment was repeated with the same results. 4. A charge of blasting gelatine, inserted in one of Settle's water cartridges, was suspended in the boiler tube and fired with a fulminate of mercury detonator in the usual manner. The gelatine did not, however, explode, the only report being that of the detonator. After a safe interval the unexploded cartridge was recovered, or so much of it as had not been scattered by the detonator, and the gelatine was found to be frozen. This fact was also evident from an inspection of other gelatine dynamite cartridges which had been stored in the same magazine during the night. This result, although not that intended, was most instructive as regards the danger of using explosives which are liable to freeze at such a moderate temperature, and the thawing of which is undoubtedly attended with great risk unless most carefully performed. Also, the small pieces of the gelatine or dynamite, when scattered by the explosion of the detonator, might cause serious accident if trodden upon. —Engineering. THE MECHANICAL REELING OF SILK. When automatic machinery for thread spinning was invented, English intelligence and enterprise were quick to utilize and develop it, and thus gained that supremacy in textile manufacture which has remained up to the present time, and which will doubtless long continue. The making of the primary thread is the foundation of all textile processes, and it is on the possibility of doing this by automatic machinery that England's great textile industries depend. The use of highly developed machinery for spinning cotton, wool, and flax has grown to be so much a part of our conception of modern life, as contrasted with the times of our grandfathers, as often to lead to the feeling that a complete and universal change has occurred in all the textile industries. This is, however, not the case. There is one great textile industry—one of the most staple and valuable—still in the primitive condition of former times, and employing processes and apparatus essentially the same as those known and employed before such development had taken place. We mean the art of silk reeling. The improvements made in the production of threads of all other materials have only been applied to silk in the minor processes for utilizing waste; but the whole silk trade and manufacture of the world has, up to this time, been dependent for its raw silk threads upon apparatus which, mechanically speaking, is nearly or quite as primitive as the ancient spinning wheels. Thousands of operatives are constantly employed in forming up these threads by hand, adding filament by filament to the thread as required, while watching the unwinding from the cocoon of many miles of filament in order to produce a single pound of the raw silk thread, making up the thread unaided by any mechanical device beyond a simple reel on which the thread is wound as finished, and a basin of heated water in which the cocoons are placed. Viewed from any standpoint to which we are accustomed, this state of things is so remarkable that we are naturally led to the belief that there must be some special causes which tended to retard the introduction of automatic machinery, and these are not far to seek. The spinning machinery employed for the production of threads, other than those of raw silk, may be broadly described as consisting of devices capable of taking a mass of confused and comparatively short fibers, laying them parallel with one another, and twisting them into a cylindrical thread, depending for its strength upon the friction and interlocking of these constituent fibers. This process is radically different from that employed to make a thread of raw silk, which consists of filaments, each several thousand feet long, laid side by side, almost without twist, and glued together into a solid thread by means of the "gum" or glue with which each filament is naturally coated. If this radical difference be borne in mind, but very little mechanical knowledge is required to make it evident that the principle of spinning machinery in general is utterly unsuited to the making up of the threads of raw silk. Since spinning machinery, as usually constructed for other fibers, could not be employed in the manufacture of raw silk, and as the countries where silk is produced are, generally speaking, not the seat of great mechanical industries, where the need of special machinery would be quickly recognized and supplied, silk reeling (the making of raw silk) has been passed by, and has never become an industrial art. It remained one of the few manual handicrafts, while yet serving as the base of a great and staple industry of worldwide importance. There is every reason to suppose that we are about to witness a transformation in the art of silk reeling, a change similar to that which has already been brought about in the spinning of other threads, and of which the consequences will be of the highest importance. For some years past work has been done in France in developing an automatic silk-reeling machine, and incomplete notes concerning it have from time to time been published. That the accounts which were allowed to reach the outer world were incomplete will cause no surprise to those who know what experimental work is—how easily and often an inventor or pioneer finds himself hampered by premature publication. The process in question has now, however, emerged from the experimental state, and is practically complete. By the courtesy of the inventor we are in a position to lay before our readers an exact analysis of the principles, essential parts, and method of operation of the new silk-reeling machine. As silk reeling is not widely known in England, it will, however, be well to preface our remarks by some details concerning the cocoon and the manner in which it is at present manufactured into raw silk, promising that if these seem tedious, the labor of reading them will be amply repaid by the clearer understanding of the new mechanical process which will be the result. The silkworm, when ready to make its cocoon, seeks a suitable support. This is usually found among the twigs of brush placed for the purpose over the trays in which the worms have been grown. At first the worm proceeds by stretching filaments backward and forward from one twig to another in such manner as to include a space large enough for the future cocoon. When sufficient support has thus been obtained, the worm incloses itself in a layer of filaments adhering to the support and following the shape of the new cocoon, of which it forms the outermost stratum. After having thus provided a support and outlined the cocoon, the worm begins the serious work of constrution. The filament from its silk receiver issues from two small spinnarets situated near its jaws. Each filament, as it comes out, is coated with a layer of exceedingly tenacious natural gum, and they at once unite to form a single flattened thread, the two parts lying side by side. It is this flat thread, called the "baye" or "brin," which serves as the material for making the cocoon, and which, when subsequently unwound, is the filament used in making up the raw silk. While spinning, the worm moves its head continually from right to left, laying on the filament in a succession of lines so...