SCIENTIFIC AMERICAN SUPPLEMENT NO. 481
NEW YORK, MARCH 21, 1885
Scientific American Supplement. Vol. XIX, No. 481.
Scientific American established 1845
Scientific American Supplement, $5 a year.
Scientific American and Supplement, $7 a year.
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TABLE OF CONTENTS.
I. ENGINEERING AND MECHANICS.—The Righi Railroad.—With 3 engravings.
The Chinese Pump.—1 figure.
The Water Clock.—3 figures.
New Self-propelling and Steering Torpedoes.
Dobson and Barbour's Improvements in Heilmann's Combers.—1 figure.
Machine for Polishing Boots and Shoes.
II. TECHNOLOGY.—The Use of Gas in the Workshop.—By T. FLETCHER.—Placing of lights.—Best burners.—Light lost by shades.—Use of the blowpipe.—Gas furnaces.—Gas engines.
The Gas Meter.—3 figures.
The Municipal School for Instruction in Watchmaking at Geneva.—1 engraving.
III. ELECTRICITY, ETC.—Personal Safety with the Electric Currents.
A Visit to Canada and the United States; or, Electricity in America in 1884.—By W.H. PREECE.
IV. ARCHITECTURE.—The House of a Thousand Terrors, Rotterdam.—With engraving.
V. GEOLOGY.—On the Origin and Structure of Coal,—With full page of illustrations.
VI. POLITICAL ECONOMY.—Labor and Wages in America.—By D. PIDGEON.—Who and what are the operatives.—Native labor.—Alien employes.—Housing of labor.—Sobriety.—Pauperism.—Artisans' homes.—Interest of employer in the condition of his employes.—Wages in Europe and America.—Expenditures of workingmen.—Free trade and protection.
VII. MISCELLANEOUS.—Ice Boat Races on the Mueggelsee, near Berlin.—With engraving.
VIII. BIOGRAPHY.—DUPUY DE LOME—With portrait.
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THE RIGHI RAILROAD.
In the year 1864, the well-known geographer, Heinrich Keller, from Zurich, on ascending to the summit of the Righi Mountain, in the heart of Switzerland, discovered one of the finest panoramic displays of mountain scenery that he had ever witnessed. To his enthusiastic descriptions some lovers of nature in Zurich and Berne listened with much interest, and in the year 1865, Dr. Abel, Mr. Escher von der Luith, Aulic Councilor, Dr. Horner, and others, in connection with Keller himself, subscribed money to the amount of 2,000 marks ($500) for the purpose of building a hotel on the top of the mountain overlooking the view. This hotel was simple enough, being merely a hut such as is to be found in abundance in the Alps, and which are built by the German and Austrian Alpine Clubs. At present the old hotel is replaced by another and more comfortable building, which is rendered accessible by a railway that ascends the mountain. Mr. Riggenbach, director of the railway works at Olten, was the projector of this road, which was begun in 1869 and completed in 1871. Vitznau at Lucerne is the starting point. The ascent, which is at first gradual, soon increases one in four. After a quarter of an hour the train passes through a tunnel 240 feet in length, and over an iron bridge of the same length, by means of which the Schnurtobel, a deep gorge with picturesque waterfalls, is crossed. At Station Freibergen a beautiful mountain scene presents itself, and the eye rests upon the glittering, ice-covered ridge of the Jungfrau, the Monk, and the Eiger. Further up is station Kaltbad, where the road forks, and one branch runs to Scheideck. At about ten minutes from Kaltbad is the so-called "Kanzli" (4,770 feet), an open rotunda on a projecting rock, from which a magnificent view is obtained. The next station is Stoffelhohe, from which the railroad leads very near to the abyss on the way to Righi-Stoffel, and from this point it reaches its terminus (Righi-Kulin) in a few minutes. This is 5,905 feet above the sea, the loftiest and most northern point of the Righi group.
The gauge of this railroad is the same as that of most ordinary ones. Between the rails runs a third broad and massive rail provided with teeth, which gear with a cogwheel under the locomotive. The train is propelled upward by steam power, while in its descent the speed is regulated by an ingenious mode of introducing atmospheric air into the cylinder. The carriage for the passengers is placed in both cases in front of the engine. The larger carriages have 54 seats, and the smaller 34. Only one is dispatched at a time. In case of accident, the train can be stopped almost instantaneously.
We give herewith, from La Lumiere Electrique, several engravings illustrating the system. Fig. 1 shows the starting station. As may be seen on Figs. 2 and 3, the method selected for obtaining adhesion permits of ascending the steepest gradients, and that too with entire security.
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HIGH SPEED STEAM ENGINE.
The use of rapidly rotating machinery in electric lighting has created a demand for engines running from 400 to 1,200 revolutions per minute, and capable of being coupled directly to a dynamo machine. We have already illustrated several forms of these engines, and now publish engravings of another in which the most noticeable feature is the employment of separate expansion valves and very short steam passages. Many high-speed engines labor under the well-grounded suspicion of being heavy steam users, and their want of economy often precludes their employment. Mr. Chandler, the inventor of the engine illustrated above, has therefore adopted a more elaborate arrangement of valves than ordinarily obtains in engines of this class, and claims that he gains thereby an additional economy of 33 per cent. in steam. The valves are cylindrical, and are driven by independent eccentrics, the spindle of the cut-off valve passing through the center of the main valve. The upper valve is exposed to the steam on its top face, and works in a cylinder with a groove cut around its inner surface. As soon as the lower edge of the valve passes below the bottom lip of the groove, the steam is cut off from the space between it and the main valve, which is fitted with packing rings and works over a latticed port. This port opens directly into the cylinder. The exhaust takes place chiefly through a port uncovered when the piston is approaching the end of its stroke. The remaining vapor left in the cylinder is exhausted under the lower edge of the main valve, until cushioning commences, and the steam from both upper and lower ports is discharged into the exhaust box shown in Fig. 2. The speed of the engine is controlled by a centrifugal governor and an equilibrium valve. This is a "dead face" valve, and when the engine is running empty it opens and closes many times per minute. The spindle on which the valve is mounted revolves with the governor pulley, and consequently never sticks. To prevent the small gland being jammed by unequal screwing up, the pressure is applied by a loose flange which is rounded at the part which presses against the gland. The governor is adjustable while the engine is running.
Another economy claimed for this engine is in the use of oil. The cranks and connecting rods work in a closed chamber, the lower part of which is filled with oil and water. The oil floats in a layer on the surface of the water, and at every revolution is splashed all over the working parts, including the interior of the cylinder, which it reaches through holes in the piston. The oil is maintained exactly at one level by a very ingenious arrangement. The bottom of the crank chamber communicates through a hole, C, with an outer box, which receives the water deposited by the exhaust steam. The level of this water is exactly determined by an overflow hole, B, which allows all excess above that level to pass into an elbow of the exhaust pipe, out of which it is licked by the passing steam and carried away. Thus, as the oil is gradually used the pressure of the water in the other leg of the hydrostatic balance raises the level of the remaining portion. When a fresh supply of oil is poured into the box, it forces out some of the water and descends very nearly to the level of the hole, B.
The engine is made with either one or two cylinders, and is, of course, single-acting. The pistons and connecting rods are of forged steel and phosphor-bronze. The following is a list of their sizes:
Single Engines. - Brake Horsepower Bore of Revolutions at 62 lb. Cylinder. per minute. Height. Floor Space. Boiler Pressure. - - - in. in. in. in. 21/4 4 1,100 26 14 by 14 31/2 5 1,000 28 14 " 15 6 61/2 800 30 16 " 16 10 8 700 32 18 " 18 -
Double Engines. - Brake Horsepower Bore of Revolutions at 62 lb. Cylinder. per minute. Height. Floor Space. Boiler Pressure. - - - in. in. in. in. 41/2 4 1,100 26 14 by 20 71/4 5 1,000 28 14 " 20 12 61/2 800 30 16 " 26 20 8 700 32 18 " 32 -
The manufacturer is Mr. F.D. Bumstead, Hednesford, Staffordshire.—Engineering.
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THE CHINESE PUMP.
If a glass tube about three feet in length, provided at its upper extremity with a valve that opens outwardly, and at its lower with one that opens inwardly, be dipped into water and given a series of up and down motions, the water will be seen to quickly rise therein and finally spurt out at the top. The explanation of the phenomenon is very simple. Upon immersing the tube in the water it fills as far as to the external level of the liquid, and the air is expelled from the interior. If the tube be suddenly raised without removing its lower extremity from the water, the valve will close, the water will rise with the tube, and, through the velocity it has acquired, will ascend far above its preceding level. Now, upon repeating the up and down motion of the tube in the water five or six times, the tube will be filled, and will expel the liquid every time that the vertical motion occurs.
We speak here of a glass tube, because with this the phenomenon may be observed. Any tube, of course, would produce the same results.
The manufacture of the apparatus is very simple. The tube is closed above or below, according to the system one desires to adopt, by means of a perforated cork. The valve is made of a piece of kid skin, which is fixed by means of a bent pin and a brass wire (Fig. 2). It is necessary to wet the skin in order that it may work properly and form a hermetic valve. The arrangement of the lower valve necessitates the use of a tube of considerable diameter (Fig. 1). We would advise the adoption of the arrangement shown in Fig. 2. Under such circumstances a tube half an inch in diameter and about 3 feet in length will answer very well.
It is better yet to simply use one's forefinger. The tube is taken in the right hand, as shown in Fig. 3, and the forefinger placed over the aperture. The finger should be wetted in order to perfect its adherence, and should not be pressed too hard against the mouth of the tube. It is only necessary to plunge the apparatus a few inches into the liquid and work it rapidly up and down, when the water will rise therein at every motion and spurt out of the top.
This is an easy way of constructing the Chinese Pump, which is found described in treatises upon hydraulics. Such a pump could not, of course, be economically used in practice on account of the friction of the column of water against a wide surface in the interior of the tube. It is necessary to consider the pistonless pump for what it is worth—an interesting experimental apparatus that any one can make for himself.—La Nature.
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THE WATER CLOCK.
To the Editor of the Scientific American:
Referring to the clepsydra, or water clock, described and illustrated in the SCIENTIFIC AMERICAN SUPPLEMENT of December 20, 1884, it strikes me that the ingenious principle embodied in that interesting device could be put into a shape more modern and practical, doing away with some of its defects and insuring a greater degree of accuracy.
I would propose the construction given in the subjoined sketch, viz.: The drum, A (Figs. 1 and 3), is mounted in a yoke suspended in such a manner as to bring no unnecessary, but still sufficient, pressure on the friction roller, B, to cause it to revolve the friction cone, C (both cone and roller being of wood and, say, well rubbed with resin so as to increase adhesion).
The friction roller should be movable (on a screw thread), but so arranged that it can be fixed at any point, say by a lock nut, screw, clamp, or other simple means. It will be evident that, by shifting the roller, a greater or less speed of the cone can be effected, and as to the end of the cone's axis an index hand sweeping an ordinary clock face is attached, the speed of this index hand can be regulated to a nicety, in proportion to that of the drum. Of course, before fixing the size and proportion of the disk and cone, the number of revolutions of the drum in a given time must be ascertained by experiment. For instance, the drum being found to make 15 revolutions in 12 hours, the proportions would be:
Circumference of roller = 12 units. Circumference of middle part of cone = 15 units.
Or, the drum making 21/2 revolutions in 3 hours, equal to 9 revolutions in 12 hours:
Circumference of roller = 12 units. Circumference of middle part of cone = 9 units.
Any slight inaccuracy can be compensated by the cone and disk device.
The drum, or cylinder, is caused to gradually revolve by a weight attached to an endless cord passing once around the drum. The latter might be varnished to prevent slipping. The weight should be provided with an automatic wedge, allowing it to be slipped along the cord in an upward direction, but preventing its descent. The weight is represented partly in section in the engraving. This weight should not be quite sufficient to revolve the drum, it being counterbalanced by the liquid raised in the chambers of the drum. The liquid, however, following its tendency to seek the lowest level, gradually runs back through the small hole, D, in the partitions, but is continually raised again, with the chamber it has just entered, by the weight slightly turning the cylinder as it (the weight) gradually gains advantage over the as gradually diminishing weight of each chamber raised.
As to the drum, the same might be constructed as follows, viz.: First solder the partitions into the cylinder, making them slanting or having the direction of chords of a circle (see Fig. 2). The end disks should be dish shaped, as shown. Place them on a level surface, apply heat, and melt some mastic or good sealing wax in the same. Then adjust the cylinder part, with its partitions, allowing it to sink into the slight depth of molten matter. In this way, or perhaps by employing a solution of rubber instead of the sealing wax, the chambers will be well isolated and not liable to leak. The water is then introduced through the center openings of the disks before hermetically sealing the drum to its axis.
The revolving parts of the clock being nicely balanced, a pretty accurate timepiece, I should think, would be the result. It is needless to mention that the "winding" is effected by slipping the weight to its highest point.
Of course I am far from considering the above an "instrument of precision," but would rather look upon it in the light of a contrivance, interesting, perhaps, especially to amateur mechanics, as not presenting any particular difficulties of construction.
ED. C. MAGNUS.
Crefeld, January 5, 1885.
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We illustrate a new form of self-propelling and steering torpedo, designed and patented by Mr. Richard Paulson, of Boon Hills, Langwith, Notts. That torpedoes will play an important part in the next naval war is evident from the fact that great activity is being displayed by the various governments of the world in the construction of this weapon. Our own Government also has latterly paid great attention to this subject.
The methods hitherto proposed for propelling torpedoes have been by means of carbonic acid or other compressed gas carried by the torpedoes, and by means of electricity conveyed by a conductor leading from a controlling station to electrical apparatus carried by the torpedo. The first method has, to a considerable extent, failed on account of the inefficient way in which the compressed gas was employed to propel the torpedo. The second is open to the objection that by means of telephones placed in the water or by other signaling apparatus the torpedo can be heard approaching while yet at a considerable distance, and that a quick speeded dredger, kept ready for the purpose when any attack is expected, can be run between the torpedo and the controlling station and the conductor cut and the torpedo captured. The arrangements for steering by means of an electrical conductor from a controlling station are also open to the latter objection. The torpedo we now illustrate, in elevation in Fig. 1, and in plan in Fig. 2, is designed to obviate these objections, and possesses in addition other advantages which will be enumerated in the following description.
As stated above, the torpedo is self-propelling, the necessary energy being stored up in liquefied carbonic acid contained in a cylindrical vessel, E, carried by the torpedo. The vessel, E, communicates, by means of a small bent pipe extending nearly to its bottom, with a small chamber, B, the passage of the liquid being controlled by means of the cock or tap, F. The chamber, B, is in communication, by means of a small aperture, with the nozzle, G, of an injector, T, constructed on the ordinary principles. The liquid as it passes into the chamber, B, volatilizes, and the gas passes through the nozzle of the injector, which is surrounded by water in direct communication with the sea by means of the opening, W. The gas imparts its energy in the well-known manner to the water, being itself entirely or partially condensed, the water thus charged with carbonic acid gas being forced through the combining cone of the injector at a very high speed and pressure. Preferably the water is here divided into two streams, each driving a separate rotary motor or turbine, H, themselves driving twin screws or propellers, I. The motors exhaust into the hollow shafts, J, of the propellers, which are extended some distance beyond the propellers, so that the remaining energy of the water may be utilized to aid in propelling the torpedo on the well known principle of jet propulsion. The torpedo is preferably steered by means of the twin screws. A disk or other valve, A, is pivoted in an aperture in a diaphragm dividing the outlet of the injector, and is operated by means hereafter described, so as to diminish the stream of water on one side and increase it on the other, so that one motor, and consequently the corresponding propeller, is driven at a higher speed than the other, and so steers the torpedo.
The valve, A, is operated automatically by the following arrangement: A mariner's compass, P, placed in the head of the torpedo has its needle connected to one pole of a powerful battery, D. A dial of non-magnetic material marked with the points of the compass is capable of being rotated by the connections shown. This dial carries two insulated studs, p, each electrically connected with one terminal of the coils of an electromagnet, K, whose other terminal is connected to the other pole of the battery. These two magnets are arranged on opposite sides of an armature fixed on a lever operating the disk or valve, A. Before launching the torpedo the dial is set, so that when the torpedo is steering direct for the object to be struck, or other desired point, one end of the needle of the compass, P, is between the steeds, p, but contact with neither, the needle of course pointing to the magnetic north. Should the torpedo however deviate from this course, the needle makes contact with one or other of the studs according to the direction in which the deviation takes place, and completes the circuit through the corresponding electromagnet, which attracts the armature and causes the disk to move, so as to diminish the supply of water to one motor and increase it to the other, and so cause the torpedo to again assume the required direction. Supposing the object which it is intended that the torpedo should strike be a large mass of iron, such as an ironclad, the needle will be attracted, and, making the corresponding contact, will cause the torpedo to be steered directly away from the object. In order to prevent this, a second compass, Q, is mounted in the front of the torpedo, and when attracted by a mass of iron, it short-circuits the battery, D, and thus prevents the armature being attracted, and consequently the torpedo from deviating. This needle is also capable of slight movement in a vertical plane, so that when passing over or under a mass of iron it is attracted downward or upward, and completes a circuit by means of the stops, which operate so as to explode the charge. The charge can also be exploded in the ordinary manner, viz., by means of the firing pin, X, when the torpedo runs into any solid object.
The depth at which the torpedo travels below the surface of the water is regulated by means of a flexible diaphragm, M, secured in the outer casing and connected to a rod sliding freely in fixed bearings. A spiral or other spring, O, is compressed between a color on the rod and an adjustable fixed nut, by which the tension of the spring is regulated so that the pressure of water on the diaphragm, A, when the torpedo is at the desired depth just counterbalances the pressure of the spring, the diaphragm being then flush with the outer casing. The rod is connected by suitable levers to two horizontal fins, S, pivoted one on either side of the torpedo, so that they shall be in equilibrium. Should the torpedo sink too deep or rise too high, the diaphragm will be depressed or extended, and will operate on the lines so as to cause the torpedo to ascend or descend as the case may be.
In order to avoid the risk of a spent torpedo destroying a friendly vessel, a valve is arranged in any suitable part of the outer casing, and is weighted or loaded with a spring in such a manner that when under way the pressure of the water keeps the valve closed, but when it stops the valve opens and admits water to sink the torpedo.
In our description we have only given the main features of the invention, the inventor having mentioned to us, in confidence, several improvements designed to perfect the details of his invention, among which we may mention the steering arrangement and arrangements for attacking a vessel provided with what our contemporary, Engineering, not inaptly terms a "crinoline," i. e., a network for keeping off torpedoes. The transverse dimensions of our engravings have been considerably augmented for the sake of clearness.—Mech. World.
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DUPUY DE LOME.
M. Dupuy De Lome died on the 1st Feb., 1885, at the age of 68. It may be questioned whether any constructor has ever rendered greater services to the navy of any country than those rendered by M. Dupuy to the French Navy during the thirty years 1840-70. Since the fall of the Empire his connection with the naval service has been terminated, but his professional and scientific standing has been fully maintained, and his energies have found scope in the conduct of the great and growing business of the Forges et Chantiers Company. In him France has undoubtedly lost her greatest naval architect.
The son of a naval officer, M. Dupuy was born in October, 1816, near L'Orient, and entered L'Ecole Polytechnique when nineteen years of age. In that famous establishment he received the thorough preliminary training which France has so long and wisely provided for those who are to become the designers of her war-ships. After finishing his professional education, he came to England about 1842, and made a thorough study of iron shipbuilding and steam navigation, in both of which we then held a long lead of France. His report, subsequently published under the title of "Memoire sur la Construction des Batiments en Fer"—Paris, 1844—is probably the best account given to the world of the state of iron shipbuilding forty years ago: and its perusal not merely enables one to gauge the progress since made, but to form an estimate of the great ability and clear style of the writer. We may assume that this visit to England, coming after the thorough education received in Francem did much toward forming the views to which expression was soon given in designs and reports on new types of war ships.
When the young constructor settled down to his work in the arsenal at Toulon, on his return from England, the only armed steamships in the French Navy were propelled by paddle-wheels, and there was great opposition to the introduction of steam power into line-of-battle ships. The paddle-wheel was seen to be unsuited to such large fighting vessels, and there was no confidence in the screw; while the great majority of naval officers in France, as well as in England, were averse to any decrease in sail spread. M. Dupuy had carefully studied the details of the Great Britain, which he had seen building at Bristol, and was convinced that full steam power should be given to line-of-battle ships. He grasped and held fast to this fundamental idea; and as early as the year 1845 he addressed a remarkable report to the Minister of Marine, suggesting the construction of a full-powered screw frigate, to be built with an iron hull, and protected by a belt of armor formed by several thicknesses of iron plating. This report alone would justify his claim to be considered the leading naval architect of that time; it did not bear fruit fully for some years, but its recommendations were ultimately realized.
M. Dupuy did not stand alone in the feeling that radical changes in the construction and propulsion of ships were imminent. His colleagues in the "Genie Maritime" were impressed with the same idea: and in England, about this date, the earliest screw liners—the wonderful converted "block ships"—were ordered. This action on our part decided the French also to begin the conversion of their sailing line-of-battle ships into vessels with auxiliary steam power. But M. Dupuy conceived and carried out the bolder scheme of designing a full-powered screw liner, and in 1847 the Napoleon was ordered. Her success made the steam reconstruction of the fleets of the world a necessity. She was launched in 1850, tried in 1852, and attained a speed of nearly 14 knots an hour. During the Crimean War her performances attracted great attention, and the type she represented was largely increased in numbers. She was about 240 ft. in length, 55 ft. in breadth, and of 5,000 tons displacement, with two gun decks. In her design boldness and prudence were well combined. The good qualities of the sailing line-of-battle ships which had been secured by the genius of Sane and his colleagues were maintained; while the new conditions involved in the introduction of steam power and large coal supply were thoroughly fulfilled. The steam reconstruction had scarcely attained its full swing when the ironclad reconstructor became imperative. Here again M. Dupuy occupied a distinguished position, and realized his scheme of 1845 with certain modifications. His eminent services led to his appointment in 1857 to the highest office in the Constructive Corps—Directeur du Materiel—and his design for the earliest seagoing ironclad, La Gloire, was approved in the same year. Once started, the French pressed on the construction of their ironclads with all haste, and in the autumn of 1863 they had at sea a squadron of five ironclads, not including in this list La Gloire. It is unnecessary to trace further the progress of the race for maritime supremacy; but to the energy and great ability of M. Dupuy de Lome must be largely attributed the fact that France took, and for a long time kept, such a lead of us in ironclads. In the design of La Gloire, as is well known, he again followed the principle of utilizing known forms and dimensions as far as was consistent with modern conditions, and the Napoleon was nearly reproduced in La Gloire so far as under-water shape was concerned, but with one gun deck instead of two, and with a completely protected battery. So long as he retained office, M. Dupuy consistently adhered to this principle; but he at the same time showed himself ready to consider how best to meet the constantly growing demands for thicker armor, heavier guns, and higher speeds. It is singular, however, especially when his early enthusiasm for iron ships is remembered, to find how small a proportion of the ships added to the French Navy during his occupancy of office were built of anything but wood.
Distinctions were showered upon him. In 1860 he was made a Councilor of State, and represented the French Admiralty in Parliament; from 1869 to 1875 he was a Deputy, and in 1877 he was elected a Life Senator. He was a member of the Academy of Sciences and of other distinguished scientific bodies. Of late his name has been little connected with ship design; but his interest in the subject was unabated.
In 1870 M. Dupuy devoted a large amount of time and thought to perfecting a system of navigable balloons, and the French Government gave him great assistance in carrying out the experiments. It does not seem, however, that any sufficient success was reached to justify further trials. The theoretical investigations on which the design was based, and the ingenuity displayed in carrying out the construction of the balloon, were worthy of M. Dupuy's high reputation. The fleet that he constructed for France has already disappeared to a great extent, and the vessels still remaining will soon fall out of service. But the name and reputation of their designer will live as long as the history of naval construction is studied.—The Engineer.
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THE USE OF GAS IN THE WORKSHOP.
At a recent meeting of the Manchester Association of Employers, Foremen, and Draughtsmen of the Mechanical Trades of Great Britain, an interesting lecture on "Gas for Light and Work in the Workshop" was delivered by Mr. T. Fletcher, F.C.S., of Warington.
Mr. Fletcher illustrated his remarks with a number of interesting experiments, and spoke as follows:
There are very few workshops where gas is used so profitably as it might be; and my object to-night is to make a few suggestions, which are the result of my own experience. In a large space, such as an erecting or moulder's shop, it is always desirable to have all the lights distributed about the center. Wall lights, except for bench work, are wasteful, as a large proportion of the light is absorbed by the walls, and lost. Unless the shop is draughty, it is by far the best policy to have a few large burners rather than a number of small ones. I will show you the difference in the light obtained by burning the same quantity of gas in one and in two flames. I do not need to tell you how much the difference is; you can easily see for yourselves. The additional light is not caused, as some of you may suppose, by a combined burner, as I have here a simple one, burning the same quantity of gas as the two smaller burners together; and the advantage of the simple large burner is quite as great. It is a well-known fact that the larger the gas consumption in a single flame, the higher the duty obtained for the gas burnt. There is a practical limit to this with ordinary simple burners; as when they are too large they are very sensitive to draught, and liable to unsteadiness and smoking. I have here a sample of a works' pendant or pillar light, which, not including the gas supply-pipe, can be made for about a shilling. For all practical purposes I believe this light (which carries five No. 6 Bray's union jets, and which we use as a portable light at repairs and breakdowns) is as efficient and economical a form as it is possible to make for ordinary rough work. The burners are in the best position, and the light is both powerful and quite shadowless; giving, in fact, the best light underneath the burners. It must, of course, be protected in a draughty shop; and on this protection something needs to be said.
Regenerator burners for lighting are coming into use; and, where large lights are required for long periods, no doubt they are economical. Burners of the Bower or Wenham class would be worth adopting for main street or open space lighting in important positions; but when we consider that, with the fifty-four hours' system in workshops, artificial light is only wanted, on an average, for four hundred hours per annum, we may take it as certain that, at the present prices of regenerator burners, they are a bad investment for use in ordinary work. We must not forget that the distance of the burner from the work is a vital point of the cost question; and, for all except large spaces, requiring general illumination, a common cheap burner on a swivel joint has yet to meet with a competitor. Do not think I am old-fashioned or prejudiced in this matter. It is purely a question of figures; and my condemnation of regenerator burners applies only to the general requirements in ordinary engineering and other work shops where each man wants a light on one spot only.
Some people think that clear glass does not stop any light. This is a great mistake, as you will find it quite easy to throw a distinct shadow of a sheet of perfect glass on a white paper, as I will show you. Opal and ground glass throw a very strong shadow, and practically waste half the light. It is better to have a white enameled or whitewashed sheet-iron reflecting hood, which will protect the sides from wind, if such an arrangement suits other requirements.
I have endeavored in the engraving below to reproduce the shadows thrown by different samples of glass. This gives a fair idea of the actual loss of light involved by glass shades.
When lights are suspended, it is a common and costly fashion to put them high up. When we consider that light decreases as the square of the distance, it will be readily understood that to light, for instance, the floor of a moulding shop, a burner 6 feet from the floor will do as much work as four burners, the same size, placed 12 feet from the floor. It is therefore a most important matter that all lights should be as low as possible, consistent with the necessities of the shop, as not only is the expense enormously increased by lofty lights, but the air becomes more vitiated and unpleasant, interfering with the men's power of working. Any lights suspended, and, in fact, all workshop lights, must have a ball-joint or universal swivel at the point where they branch from the main, as they are liable to be knocked in all directions, and must, therefore, be free to move to prevent accidents. It is better to have wind-screens, if necessary, rather than glass lanterns, as not only does the glass stop a considerable amount of light when clean, but it is in practice constantly dirty in almost every workshop or yard.
For bench work and machine tools, each man must have his own light under his own control; and in this matter a little attention will make a considerable saving. The burners should be union jets—i. e., burners with two holes at an angle to each other—not slit or batswing, as the latter are extremely liable to partial stoppage with dust. Where batswing burners are used, I have often seen fully 90 per cent. more or less choked and unsatisfactory; whereas a union jet does not give any trouble. It is not generally known that any burner used at ordinary pressures of gas gives a much better light when it is turned over with the flat of the flame horizontal, until the flame becomes saucer-shaped, as I show you. You can see for yourselves the increase in light; and in addition to this the workman has the great advantage of a shadowless flame. In practice, a burner consuming 5 cubic feet of gas per hour with a horizontal flame is a better fitter's than an upright burner with 6 cubic feet per hour. I do not believe in the policy of giving a man a poor light to work by—it does not pay; and I never expect to get a man to work properly with smaller burners than these. We have a good governor on the main: and the lights are all worked with a low pressure of gas, to get the best possible duty. As a good practical light for a man at bench moulding, the one I have here may be taken as a fair sample. It is free to move, and the light is as near the perfect position as the necessities of the work will permit. When the light is not wanted, by simply pushing it away it turns itself down; the swivel being, in fact, a combined swivel and tap.
You will see on one of the lights I have here, a new swivel joint, which has been patented only within the last few days. The peculiarity of this swivel is that the body is made of two hemispheres revolving on each other in a ground joint. It will be made also with a universal movement; and its special advantage, either for gas, water, or steam, is that there is no obstruction whatever to a free passage—in fact, the way through the swivel body is larger than the way through the pipes with which it is connected. It can easily be made to stand any pressure, and if damaged by grit or dirt it can be reground with ease as often as necessary without deterioration, whereas an ordinary swivel, if damaged by grit, has to be thrown away as useless.
For meals, where a steam-kettle is not used, it is the best policy to have a cistern holding about 11/2 pints for each man, and to boil this with a gas-burner. The lighting of the burner at a specified time may be deputed to a boy. If the men's dinners have to be heated, it is easy to purchase ovens which will do all the work required by gas at a much cheaper rate than by coal, if we consider the labor and attention necessary with any coal fire. Not that gas is cheaper than coal; but say we have 100 dinners to warm. This can be done in a gas-oven in about 20 minutes, at a cost for gas of less than 1d.; in fact, for one-fourth the cost of labor only in attending to a coal fire, without considering the cost of wood or coals. Gas, in many instances, is an apparently expensive fuel; but when the incidental saving in other matters is taken into consideration, I have found it exceedingly profitable for all except large or continuous work, and in many cases for this also. I only need instance wire card-making and the brazing shops of wire cable makers to show that a large and free use of gas is compatible with the strictest economy and profitable working.
Of all the tools in a workshop, nothing saves more time and worry than two or three sizes of good blowpipes and an efficient blower. I have seen in one day more work spoilt, and time lost, for want of these than would have paid for the apparatus twice over; and in almost every shop emergencies are constantly happening in which a good blowpipe will render most efficient service. Small brazing work can often be done in less time than would be consumed in going to the smith's hearth and back again, independently of the policy of keeping a man in his own place, and to his own work. The shrinking on of collars, forging, hardening, and tempering of tools, melting lead or resin out of pipes which have been bent, and endless other odd matters, are constantly turning up; and on these, in the absence of a blowpipe, I have often seen men spend hours instead of minutes. Things which need a blowpipe are usually most awkward to do without one; and men will go fiddling about and tumbling over each other without seeing really what they intend to do. They are content, as it all counts in the day's work; that it comes off the profits is not their concern. It will, perhaps, be new to many of you that blowpipes can easily be made in a form which admits of any special shape of flame being produced. I have made for special work—such as heating up odd shapes of forgings, brands, etc.—blowpipes constructed of perforated tubes formed to almost every conceivable shape; these being supplied with gas from the ordinary main and a blast of air from a Root's or foot blower. I have here an example of a straight-line blowpipe made for heating wire passed along it at a high speed. The same flame, as you no doubt will readily understand, can be made of any power and of any shape, and will work any side up; in fact, as a rule, a downward vertical or nearly vertical position is usually the best for any blowpipe. As an example of this class of work, I may instance the shrinking on of collars and tires, which, with suitable ring-burner and a Root's blower, could be equally heated in five minutes for shrinking on; in fact, the work could be done in less time than it would usually take to find a laborer to light a fire. When the rings vary much in size, the burners can easily be made in segments of circles. But then they are not nearly so handy, as each needs to be connected up to the gas and air supply; and it is, in practice, usually cheaper to have separate ring burners of different sizes. Of course, you will understand that a 1/2-inch gas-pipe will not supply heat enough to make a locomotive tire red hot, and that for large work a large gas supply is necessary. Our own rule for burners of this class is that the holes in the tube should be 1/8 to 1/10 inch in diameter, from 1/4 to 1/2 inch pitch; and the area of the tube must be equal to the combined area of the holes. The gas supply-pipe must not be less than half the area of the burner-tube. Those of you who wish to study this matter further will, I think, find sufficient information in my paper on "The Construction of High-Power Burners for Heating by Gas," printed in the Transactions of the Gas Institute for 1883, and in the papers on the "Use and Construction of the Blowpipe" and "The Use of Gas as a Workshop Tool."
No doubt many of you have been troubled with the twisting of some special light casting, and will, perhaps, spend hours in the risky operation of bending an iron pattern so as to get a straight casting. A ladleful of lead and tin, melted in a small gas-furnace, will, in a few minutes, give you a pattern which you can bend and adjust to any required shape. It enables you to make trials to any extent, and get castings with the utmost precision. There is also this advantage, that a soft metal pattern can be cut about and experimented with in a way which no other material admits of. Awkward patterns commence with us with plaster, wax, sheets of wet blotting paper pasted together on a shape or wood; but they almost invariably make their appearance in the foundry after being converted into soft metal by the aid of a gas-furnace. I refer, of course, to thin, awkward, and generally difficult castings, which, under ordinary treatment, are either turned out badly or require a great amount of fitting. As an illustration of the use of this system of pattern-making, I have here two castings of my own, from patterns which, under the ordinary engineer's system, would be excessively costly and difficult to make as well as these are made. The surface is a mass of intricate pattern work and perforations. To produce the flat original, as you see it, a small piece of the pattern is first cut, and from this a number of tin castings are made and soldered together. From this pattern, reproduced in iron for the sake of permanence, is cast the flat center plate you see. To produce the curved pattern I show you, nothing more is necessary than to bend the tin pattern on a block of the right shape, and we now get a pattern which would puzzle a good many pattern-makers of the old style.
I will now show you by a practical utilization of the well known flameless combustion, how to light a coke furnace without either paper or wood, and without disturbing the fuel, by the use of a blowpipe which for the first minute is allowed to work in the ordinary way with a flame to ignite the coke. I then pinch the gas tube to extinguish the flame, allow the gas to pass as before, and so blow a mixture of unburnt air and gas into the fuel. The enormous heat generated by the combustion of the mixture in contact with the solid fuel will be appreciable to you all, and if this blast of mixed air and gas is continued, there is hardly any limit to the temperatures which can be obtained in a furnace. I shall be able to show you the difference in temperature obtained in a furnace by an ordinary air blast, by a blowpipe flame directed into the furnace, and by the same mixture of gas and air which I use in the blowpipe being blown in and burnt in contact with the ignited coke. In each case the air blast, both in quantity and pressure, is absolutely the same; but the roar and the intense, blinding glare produced by blowing the unburnt mixture into the furnace is unmistakable. The heat obtained in the coke furnace I am using, in less than ten minutes, is greater than any known crucible would stand. I am informed that this system of air and gas or air and petroleum vapor blast, first discovered and published by myself in a work on metallurgy issued in 1881, is now becoming largely used for commercial purposes on the Continent, not only on account of the enormous increase in the heat, and the consequent work got out of any specified furnace, but also because the coke or solid fuel used stands much longer, and the dropping, which is so great a nuisance in crucible furnaces, is almost entirely prevented; in fact, once the furnace is started, no solid fuel is necessary, and the coke as it burns away can be replaced with lumps of broken ganister or any infusible material. Few, if any, samples of firebrick will stand the heat of this blast, if the system is fully utilized. You will find it a matter of little difficulty, with this system of using gas, to melt a crucible of cast iron in an ordinary bed-room fire grate if the front bars are covered with sheet iron, with a hole (say) three inches in diameter, to admit the combined gas and air blast. The only care needed is to see that you do not melt down the firebars during the process. I will also show you how, on an ordinary table, with a small pan of broken coke and the same blowpipe, used in the way already described, you can get a good welding heat in a few minutes, starting all cold. In this case the blowpipe is simply fixed with the nozzle six inches above the coke, and the flame directed downward. As soon as the coke shows red, the gas pipe is pinched so as to blow the flame out, and the mixture of gas and air is blown from above into the coke as before. With this and a little practice, you can get a weld on a 7/8 inch round bar in 10 minutes.
There is one use of gas which has already proved an immense service to those who, in the strictest sense, live by their wits. In a small private workshop, with the assistance of gas furnaces, blowpipes, and other gas heating appliances, it is a very easy matter to carry out important experiments privately on a practical scale. A man with an idea can readily carry out his idea without skilled assistance, and without it ever making its appearance in the works until it is an accomplished fact. How many of you have been blocked in important experiments by the tacit resistance of an old fashioned good workman, who cannot or will not see what you are driving at, and who persists in saying that what you want is not possible? The application of gas will often enable you to go over his head, and do what, if the workman had his own way, would be an impossibility. When a man is unable or unwilling to see a way out of a difficulty, a master or foreman has the power to take the law in his own hands; and when a workman has been met with this kind of a reply once or twice, he usually gives way, and does not in future attempt to dictate and teach his master his own business. In carrying out this matter, it is not necessary that a specimen of fine workmanship shall be produced. A man usually appreciates the wits which have produced what he has considered impossible. In purely experimental work I think I may fairly state that the use of gas as a fuel in the private workshop and laboratory has done incalculable service in the improvement of processes and trades, and has played an important part in insuring the success and fortunes of many hundreds of experimenters, who have brought their labors to a successful issue in cases where, in its absence, neither time nor patience would have been available. I need only to call to your mind the number of new alloys which, for almost endless different purposes, have come into use during the last eight or ten years. I think the use of small gas furnaces in private workshops and laboratories may fairly be said to have enabled the experiments on most, if not all, of these alloys to be carried out to a successful issue.
I have been asked to say something regarding gas engines. The only thing I can say is that I know very little about them. In my own works we have about 300,000 cubic feet of space, all of which requires to be heated, more or less, during the greater part of the year. For this purpose we must have a steam boiler, and having this steam, it costs little to run it first through the engine, and so obtain our power for a good part of the year practically without any cost. It would not pay, under any circumstances, to have two separate sources of power for summer and winter; and therefore the use of gas for power has never been considered.
For irregular work and comparatively small powers, gas-engines have special and great advantages; and in this respect they may, perhaps, class with gas melting furnaces. If I wanted 1, or 10, or 20 lb. of melted metal, I could melt and make the casting in less time and with less cost than would be required to light a coke fire. There is no possible comparison in the two, as to convenience and economy; but if I wanted to melt 3 or 4 cwt. or 3 or 4 tons every day, I should not dream of using gas for the purpose, as the extra cost of gas in such a case would not be compensated by the saving in time. In commercial matters we must always consider first what is the most profitable way of going about our work; and, so far as I myself am concerned, I have always found it advantageous to expend some money annually on proving this by direct experiment. It is almost always possible to learn something, even from a failure.
I will now, with a blowpipe and small foot blower, heat a short length of locomotive boiler tube to a brazing heat on the table; and, in conclusion, will convert the table into a small foundry. I cannot cast you a flywheel for a factory engine; so will try at something smaller, and will reproduce a medallion portrait of Her Majesty, in cast iron, the original of which is silver, commonly valued at half a crown. From the time I light the furnace until I turn you out the finished casting I shall perhaps keep you eight or nine minutes. I can remember in the good old times 25 years ago, before I used gas furnaces, that it sometimes took about two hours to get a good wind furnace into condition to put the crucible in. My time in those days was not worth much; but if I valued it at 2s. 6d. per week, it would even then have been cheaper to use gas to do the same thing, irrespective of the cost of coke.
The age of gaseous fuel is commencing; and I feel daily, from the correspondence I receive, that there is a growing impression that gas is going to perform miracles. We do not need to go mad about it; and my own precept and practice is to employ gas only where its use shows a profit, either in time or money. Many of those present know that I am as ready to totally condemn gaseous fuel where it does not pay as to advise its use where some advantage is to be gained. You will understand that my remarks apply to coal gas only. As to producer or furnace gases, I know practically nothing, except that sometimes it pays better to burn your candle as a candle than make it into gas, and burn it as a gas afterward. The use of producer gas no doubt pays on a large scale; and things on a large scale, so far as gas is concerned, are not matters with which I have time to concern myself. The commercial use of coal gas has yet to be developed. It is in its infancy; and there are very few, if any, who have any conception of its endless uses, both for domestic and manufacturing purposes. The more general the information which can be given about its uses, the sooner it will find its own level, and the sooner the gas companies will appreciate the fact that their best customers are to be found among those who can use coal gas as a fuel for special work in manufacturing industries because it is profitable to use, and saves expensive labor. My own experiments with alloys of the rarer metals, which have not been concluded without profit to myself, would certainly never have been undertaken except with the use of gas furnaces, which were both practically unlimited in power and admitted of the most absolute precision in use; and I may safely say, without violating any confidence, that many of the precious stories and so-called "natural" products make their appearance in the world first in a crucible in a gas furnace.
At the conclusion of my lecture before the Institute at Leeds, on "Combustion and the Utilization of Waste Heat," Mr. Kitson, the Chairman, remarked that if he were a dreamer of dreams, he might look forward to the time when he would be growing cucumbers with the waste heat of his iron furnaces. Many wilder dreams than this have come true in the science of engineering; and the realization has brought honor and fortune to the dreamers, as you must all know. The history of engineering is full of the realization of "dreams," which have been denounced as absurdities by some of the best living authorities.
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THE GAS METER
The gas meter was invented by Clegg in 1816. Since that epoch no essential modification has been made of its structure. Fig. 1 shows the principle of the apparatus, mnpq is a drum movable around a horizontal axis. This is divided by partitions of peculiar form into four vessels of equal capacity, and dips into a closed water reservoir, RR'. A tube, t, near the axis, and the orifice of which is above the level of the water, leads the gas to be measured. This latter enters under the partition, l'm, of one of the buckets, and exerts an upward thrust upon it that communicates a rotary motion to the drum. The bucket, l'mi, closed hydraulically, rises and fills with gas until the following one comes to occupy its place above the entrance tube and fills with gas in turn. Simultaneously, as soon as the edge of each bucket emerges at e, the gas flows out through the opening that the water ceases to close, and escapes from the reservoir through the exit aperture, S. The gas, in continuing to traverse the system, is thus filling one bucket while the preceding one is losing its contents; so that, if the capacity of each bucket is known, the volumes of the gas discharged will likewise be known when the number of revolutions made by the drum shall have been counted. The addition of a revolution counter to the drum, then, will solve the problem.
The instrument, as usually constructed, is shown in Figs. 2 and 3.
The reservoir, RR' contains the measuring drum, mmmm, movable around the horizontal axis, aa'. The gas enters at E, passes at S into an opening that may be closed by a valve, and is distributed through the box, BB', which communicates with the reservoir through an orifice in the partition, hh'. This orifice is traversed by the axle, aa'. The box, like the reservoir, contains water up to a certain level, r. Through a U-shaped tube, lnl', the gas passes from the box, BB', into the movable drum, sets the latter in motion, and makes its exit at S. In order to count the volume discharged, that is to say, the number of revolutions of the drum, the axle terminates at a in an endless screw which, by means of a cog wheel, moves a vertical rod that traverses the tube, gg, and projects from the box. As the tube, gg, dips into the water, it does not allow the gas to escape, and this permits of the revolution counter that the rod actuates being placed in an external case, CC'.
The counter consists of toothed wheels and pinions so arranged that if the first wheel makes one complete revolution corresponding to a discharge of 1,000 liters, the following wheel, which indicates cubic meters, shall advance one division, and that if this second wheel makes one complete revolution marked 10 cubic meters, the third, which indicates tenths, shall advance one division, and so on. Hands fixed to the axles of the wheels, and movable over dials, permit the volume of gas to be read that has traversed the counter.
The object of the other parts of the instrument are to secure regularity in its operation by keeping the level of the liquid constant. It is evident, in fact, that if the level of the water gets below r, the capacity of the buckets will be increased, and the counter will indicate a discharge less than is really the case, and vice versa. If the level descends as far as to the orifice in the partition, hh', the gas will flow out without causing the apparatus to move. The water is introduced into the counter through f, which is closed with a screw cap, and passes through the opening shown by dotted lines into the reservoir, RR', whence it flows to the box, BB', When it has reached the desired level, it gains the orifice, r, of a waste pipe, escapes through the siphon, ruv, and makes its exit through the aperture, b', when the screw cap of the latter is removed. If, by accident, the level of the water should fall below a certain limit, a float, f, which follows its every movement, would close the valve, s, and stop the flow of the gas. Finally a tube, tt' soldered to the lower part of the tube, lnl', and dipping into the water of a compartment, P, serves to allow the surplus water to flow out at b'. To prevent the apparatus from being disarranged upon the drum being revolved in the opposite direction, there is fixed to the axle, aa', a cam which lifts a click, z, when the rotation is regular, but which is arrested by it when the contrary is the case.—Science et Nature.
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DOBSON AND BARLOW'S IMPROVEMENTS IN HEILMANN'S COMBERS.
Next to the mule, there is no doubt that the most beautiful machine used in the cotton trade is Heilmann's comber. Although the details of this machine are hard to master, when once its action is understood it will be found to be really simple. The object of combing is to remove the short staples and the dirt left in after the carding of the cotton, such as is used in the spinning of fine and even coarse numbers. The operation is an extremely delicate one, and its successful realization is a good illustration of what is possible with machinery. Combing machines are usually made with six heads, and sometimes with eight. As the working of each head is identical, we only speak of one of them. By means of a pair of fluted feeding rollers a narrow lap, about 71/2 in. wide, is passed into the head, in which the following action takes place: Assuming that the stroke is finished, the lap is seized near its end by a pair of nippers, so as to leave about half the length of the staple projecting. These projecting fibers are combed by a revolving cylinder, partially covered with comb teeth. When the front or projecting ends of the fibers are thus combed, a straight comb in front of the nippers drops into them, the nippers open, and the fibers are drawn through the straight comb. This combs the tail ends, and at the same time the fibers, now completely combed, are placed on or pieced to the fibers that had been combed in the previous stroke, producing in this way a continuous fleece of combed cotton. In short, in this most striking operation, the fiber during the combing is completely detached from the ribbon lap, carried over, and pieced to the tail end of the combed fleece, for a moment having no connection with either. Since the expiry of the patent, Messrs. Bobson and Barlow, of Bolton, have constructed a great many of these machines, and have found that, as compared with the original make, it was possible to greatly increase their efficiency. They accordingly devoted much attention to this object, and have patents for several improvements. To describe these so as to be understood by everybody would be a most difficult task, and would take more space than we can afford. We simply wish to record what these improvements are, and will suppose we are writing for those who have a good acquaintance with Heilmann's comber.
We give herewith a perspective view of the improved machine. On examination it will be noticed that an alteration is made in the motion seen at the end of the machine for working the detached rollers. This alteration we believe to be a decided improvement over Heilmann's original arrangement. It dispenses with the large detaching cam, the cradle, the notch-wheel, the catch and its spring, the large spur wheel which drives the calender roller, and the internal wheels for the detaching roller-shaft, substituting in their stead a much simpler motion, consisting of a smaller cam, a quadrant, and a clutch. The arrangement, having fewer parts, is also much more compact than the old one, for with the driving pulleys in the best position it enables the machine outside the framing to be shortened 10 in., an important point in a room full of combers. The action of this detaching motion is positive, and enables the machine to be run at a high speed without danger of missing, as happens when the point of the catch for the old notch-wheel becomes broken or worn away. Another important feature of the new arrangement is that it allows the motion of the detaching-roller to be varied. By an adjustment, easily made in a few seconds, the delivery may be altered to suit different classes of cotton or kinds of work without the necessity of changing the cams or the notch-wheels.
An improvement has been made in the construction of the nippers. In the ordinary Heilmann's comber, the upper blade has a groove in its nipping edge, and the cushion plate is covered with cloth and leather, the fibers being held by the grip between the leather of the cushion plate and the edges of the groove in the upper blade, or knife, as it is called. The objections to this mode of construction were that the leather on the cushion plate required frequent renewing, and unless the adjustment was more accurate than could always be relied on, the grip of the nippers was not perfect, for while at one end the nipper might be closed, at the other end it might be open wide enough to allow the cotton to be pulled through by the combing cylinder, and made into waste. In Messrs. Dobson and Barlow's nipper there is neither cloth nor leather on the cushion plate. Its edge is made into a blunt ^, upon which the narrow flat surface of a strip of India rubber or leather fixed in the knife falls to give the nip. By this plan the cushion is applied to the knife instead of to the plate, which of course makes the cushion plate, after it has once been set, a fixture; it also dispenses with the accurate setting, as is now necessary in the old arrangement. It further does away with the frequent and expensive covering of the cushion-plate with roller leather and cloth, thus effecting a considerable saving, not only in cost of material, but also in labor, inasmuch as the nipper knives can be taken off, recovered, and replaced in one-sixth the time required to cover the cushion plates and replace them on the old system. American cotton of 7/8" staple to silk of 21/2" staple can also be combed by this improved arrangement, an achievement which has been attempted by many, but hitherto without arriving at any success. Messrs. Dobson and Barlow have however overcome the difficulty by their improvements, which combine three important qualities, viz., simplicity, perfection, and cheapness. Many hundreds of other makers' machines have been altered to their new arrangements. The cam for working the nipper has also been altered to give a smoother motion than usual; one that moves the nipper quietly and without jerks when the machine runs from 80 to 95 strokes per minute. A very decided improvement has been made in the construction of the combing cylinder. The combs are always fixed on a piece called the "half-lap," which, in its turn, is secured to a barrel called the "comb-stock." Now it is very desirable and important that these half-laps should be perfectly true and exactly interchangeable. When one half-lap is taken off for repairs, another half-lap must be ready to take its place on the cylinder. The original mode in which the cylinders were made rendered it a matter of mechanical difficulty—almost an impossibility in the machine shop—to produce them exactly alike. To avoid this difficulty, Messrs. Dobson and Barlow have reconstructed the combing cylinder, and the parts being fitted together by simple turning or boring, accuracy and interchangeability can always be depended upon. The screws which fasten the cylinder to the shaft are also cased up with the cylinder tins, thus avoiding any accumulation of fly on the screw heads.
The motion for working the top detaching, the leather, or the piecing roller, as it is variously called, has also been improved. The ends of this roller are always carried on the top of two levers that are oscillated by a connecting rod attached to their bottom ends. In the new motion the connecting rod is dispensed with, and one joint saved. The joint that remains is at the foot of the levers that carry the leather roller. This joint is constructed so that it may be easily altered, and by its means one of the most delicate settings of the combing machine, viz., that of the leather roller, may be made with greater readiness than with the old system. Further, from the mode of mounting these rollers another advantage is gained in the facility of setting them. In setting with the old arrangement, only one end of the roller is adjusted at a time; in the new, the adjustment sets the ends of two rollers. With regard to the leather roller also, it was found that as the round brass tubes in which its ends revolved had very little wearing surface, they got worn into flats on the outside, and thus worked inaccurately. In the machine under notice this defect is remedied. The tubes are made square on the outside, and having ample bearing surface they keep their adjustment perfectly.
On the top of the detaching roller is a large steel fluted roller carried at each end by a small arm called a "horse tail." In the original machine this roller simply kept its place upon the detaching roller by its weight, and when the machine came to be run at high speeds it was found that owing to its lightness the contact thus obtained was not reliable, the flutes or ribs of the roller slipping upon those of the detaching roller, which for good work is undesirable. This is remedied by placing a heavier top roller in the horse tails, which is made with a broader bearing so as to give greater solidity to the top roller. Another good idea we noticed in this machine was in the application of a treble brush carrier wheel, which permits of the brushes being driven at three different speeds as they become worn. For instance, when the brushes are new the bristles are long, and consequently they are not required to revolve as quickly as when the bristles are far worn. By this improvement the brush lasts considerably longer than in any other system of machine. Their speed can also be regulated according to the length of the bristles, and the change from one speed to the other can be effected in a very few minutes.
A common defect in combing machines is the flocking that frequently happens. This is the filling up of the combs on the cylinder with dirt and cotton, which the brush fails to remove. Although in general appearance the cleaning apparatus is the same as the ordinary one, modifications are introduced which make its action always effective and reliable. We were informed by a mill manager, who has a great number of these combers, that he meets with no inconvenience from flocking from one week end to another. Altogether, it will be seen that Messrs. Dobson and Barlow have almost reconstructed the machine, strengthening and improving those parts which experience showed it was necessary to modify. As a result their improved machine works at a high speed (80 to 95 strokes per minute, according to the class of cotton), with great smoothness and without noise, and from the almost complete absense of vibration the risk of breakages is reduced to a minimum.—Textile Manufacturer.
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THE MUNICIPAL SCHOOL FOR INSTRUCTION IN WATCH-MAKING, AT GENEVA.
When, in 1587, Charles Cusin, of Autun, settled at Geneva and introduced the manufacture of watches there, he had no idea of the extraordinary development that this new industry was to assume. At the end of the seventeenth century this city already contained a hundred master watch makers and eighty master jewelers, and the products of her manufactures soon became known and appreciated by the whole world.
The French revolution arrested this impetus, but the entrance of the Canton of Geneva into the Confederation in 1814, rendered commerce, the arts, and the industries somewhat active, and watch-making soon saw a new era of prosperity dawning.
On the 13th of Feb., 1824, at the instigation of a few devoted citizens, the industrial section of the Society of Arts adopted the resolution to form a watch-making school, which, having been created by private initiative, was only sustained through considerable sacrifices.
In 1840 the school was transferred to the granary building belonging to the city. In 1842, when it contained about fifty pupils, it was made over to the administrative council of the city by the committee of the Society of Arts. From 1824 to 1842 the school had given instruction to about two hundred pupils. From 1843 to 1879 it was frequented by nearly eight hundred pupils, two-thirds of whom were Genevans, and the other third Swiss of other cantons and foreigners.
The school, then, has furnished the watch-making industry with the respectable number of a thousand workmen, among whom large numbers have been, or are yet, distinguished artists.
The rooms of the granary, where the school remained for nearly forty years, became inadequate, despite the successive additions that had been made to them, and it became necessary to completely transform them. The magnificent legacy that the city owes to the munificence of the Duke of Brunswick was partly employed in the reorganization, and the school is now located in a vast building designed to answer the requirements of instruction. This structure, which is located in Necker Street, presents an imposing and severe aspect. The main building embraces most of the workshops, the office, the library, and the classroom for instruction in mechanics, all of which receive a direct light. At right angles with the main building are two wings. The one to the north contains in its three upper stories workshops occupied by classes in escapements, bezil setting, compensating balances, and ruby working. On the ground floor are installed juvenile schools.
The south wing contains halls for lectures on theory, and two workshops looking toward the north. The ground floor is used for the same purpose as that of the north wing.
Finally, in the center of the main building is a wing parallel with its two mates. It is in this that is located the vast staircase that leads to spacious landings at which ends on every story a large corridor common to all the halls and workshops. It is in this part of the building that we find the amphitheater of physics and chemistry and the laboratories. Here also is located the museum in course of formation (gotten up in view of the historical study of watch-making), and the amphitheater designed for certain public lecture courses.
In the way of heating and lighting all parts of the building nothing has been neglected, and special care has been taken to have the ventilation perfect.
At present the instruction comprises a practical and a theoretical course.
Practical Instruction.—This is divided into three sections: (1) an elementary one having in view the construction of the simple watch in its essential parts; (2) a higher section in which the pupils learn to recognize the complicated parts; and (3) a section of mechanics applied to watch-making and to the study of the construction of machines and tools for facilitating and improving the manufacture.
1. Elementary Section, First Year.—The pupil must manufacture all the small tools necessary for making unfinished movements; that is, drills, reamers, punches, files, etc. He must then learn to file and turn, and to make use of the finishing lathe with the bow, or of the foot lathe.
In general, the time taken by an apprentice to manufacture his tools is from two to three months, and he can scarcely go to work on the movements before this.
In this class the regular pupils have to execute seven pieces of work in the rough, two for horizontal escapements with key and regulating wheel, and five for various other escapements. Among these there is one for simple repetition and one for minute piece. Aside from the work fixed by the programme, the pupils may manufacture all the other complicated pieces upon obtaining the authority for it from their masters and the director.
The average time employed in performing the work imposed by the programme necessarily depends upon the capacity of the pupil, but we may say that in general ten months are necessary.
Second Year.—After executing his last piece of work in a satisfactory manner, the apprentice passes into the class in regulators, where he begins to manufacture the small tools that he will require.
In this work, as in the preceding, he must take all his pieces from the crude metal, and he must do the forging himself, as well as the roughing down, the turning, filing, and shaping, and finally the finishing, without the aid of any other machine than the dividing one.
In general, after eighteen months of work, the apprentice goes to the finishing shop, where the delicate and minute work begins, pivoting, putting the wheels in place, and practical study of gearings. After learning how to divide a wheel correctly, he is set to work on pinions and wheels in the rough, which he must rivet, finish, and pivot according to the different planes of the pieces that have been calculated and executed by him under the direction of the master.
The programme to be followed by the pupils of the class in finishing is, as regards number of pieces, the same as that of the preceding classes, that is to say, seven.
In general, the pupil passes from the class in finishing to the class in dial-trains, where he makes two of these for his pieces—one a simple and the other a minute train. The teaching of this part is very important as regards the manufacture of escapements. In constructing the dial train, the pupil perfects his filing and learns to make the adjustments correct.
The last class in the elementary instruction is the one in escapements (Fig. 1), the programme of which includes several distinct parts: (1) The tools that are strictly necessary; (2) escapement and cylinder adjustment; (3) making the compensating balances for the pupil's pieces; (4) pivoting, putting in place, and finishing the escapements in regulating pieces. Here, as in the preceding classes, the pupils must do all the work themselves. During their stay in the elementary classes the work done is submitted to the director, who examines it and sends it back to the instructors accompanied with a bulletin containing his estimate as to its value, and his observations if there is occasion to make any.
Pupils who cannot or who do not wish to go over the entire field of the programme stop here, and are now capable of earning their living and of lightening the load that oppresses their parents.—Science et Nature.
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MACHINE FOR POLISHING BOOTS AND SHOES.
The principle of an apparatus for blackening boots and shoes dates back to 1838, the epoch at which a machine of this kind was put into use at the Polytechnic School. Since then it seems that not many applications have been made of it, notwithstanding the services that a machine of this kind is capable of rendering in barracks, lyceums, hotels, etc. Mr. Audoye, an inventor, has recently taken up the question again, and has proposed to The Societe d'Encouragement a model that gives a practical solution of it. The use of this will allow a notable saving in time and trouble to be effected.
This brush (see engraving) revolves around a horizontal axle supported by a cast iron frame similar to that of a sewing machine. Motion is communicated to it by a double pedal, which actuates a connecting rod and a system of pulleys. The external surface of the brush contains three channels in which the foot gear to be polished is successively placed. In the first of these the dust and mud are removed, in the second the blacking is spread on, and in the third the final polish is obtained.
In order to guide the blacking to that part of the brush which is to receive it, Mr. Audoye protects the lower part of the latter by a half-cylinder of sheet iron. On this there is placed a vessel containing the blacking, and into which dips a copper cylinder having a grooved surface. The horizontal axis of this cylinder is movable; when at rest it is so placed that the cylinder is an inch or so below the brush, but when the operator pulls a button that is within reach of his left hand, the axis is lifted, a contact takes place between the brush and the cylinder, and the former is thus given a rotary motion. As the cylinder still continues to dip into the blacking, the latter is thus spread ever the brush.—La Genie Civil.
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PERSONAL SAFETY WITH THE ELECTRIC CURRENTS.
To the Editor of the Scientific American:
In your paper of the 21st of February there is an article on personal safety with electric currents, by Prof. A.E. Dolbear. He says that a Holtz machine may give through a short wire a very strong current. For if E = 50,000 volts, R = 0.001 ohm, then C = 50000/0.001 = 50,000,000 amperes. Now that is a very large quantity of electricity, and is equal to an enormous horse power. I think the person receiving that charge would not need another. According to Ohm's law, the strength of current is proportional to the electromotive force divided by the total resistance, external and internal. The last is a very important element in the Holtz machine, and will make a big difference in the current strength. Here are some of the results obtained from experiments made with the Holtz machine. A machine with a plate 46 in. in diameter, making 5 turns in 3 seconds, produced a constant current capable of decomposing 31/2 millionths of a milligram in a second. This is equal to the effect produced by a Grove's cell in a circuit of 45,000 ohms resistance. The current produced would be about 0.0000044 ampere. That is rather small compared with the Professor's result. Rossetti found that the current is nearly proportional to the velocity of rotation. It increases a little faster than the velocity.
The electromotive force and resistance is constant if the velocity is constant. The electromotive force is independent of the velocity, but diminishes as the moisture increases, and is about equal to 52,000 Daniell cells. The resistance when making 120 revolutions per minute is 2,810 million ohms. At 450 per minute, 646 million.
Taking it at 450, C = 53950/64600000.001 = 0.0000835 ampere, against the Professor's 50,000,000, amperes, and it would be equal to about 0.006 horse power, which I think would be the more correct of the two; calling E equal to 50,000 Daniell cells.
Portland, Me., March 5, 1885.
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A VISIT TO CANADA AND THE UNITED STATES IN THE YEAR 1884.
[Footnote: A lecture delivered before the Society of Telegraph Engineers and Electricians, London, Dec. 11, 1884.]
By Mr. W.H. PREECE, F.R.S.
I do not know what the sensations of a man can be who is about to undergo the painful operation of execution; but I am inclined to think his sensations must be somewhat similar to those of a lecturer, brimful of notes, who has to wait until the clock strikes before he is allowed to address his audience.
The President has been kind enough to refer to the paper I propose to give you, as "Electricity in America in the year 1884;" but I would rather, after having thought more about it, that it be called "A Visit to Canada and the United States in the year 1884."
It will be in the recollection of a good many who are present that in the year 1877 I visited America, in conjunction with Mr. H.C. Fischer, the Controller of our Central Telegraph Station, to officially inspect and report upon the telegraph arrangements of that country; and on the 9th February, 1878, I had the pleasure of communicating to the members of this Society my experiences of that visit.
During the present year my visit was not an official one; I went for a holiday, and specially to accompany the members of the British Association, who, for the first time in the history of that association, held a meeting outside the limits of the United Kingdom.
We sailed from Liverpool in a splendid steamship called the Parisian. There were nearly 200 B.A. members on board; and notwithstanding the fact that rude Boreas tried all he could to prevent us from reaching the other side of the Atlantic; notwithstanding the fact that the Atlantic expressed its anger in the most unmistakable terms at our audacity in turning from our native shore; notwithstanding the fact that Greenland's icy mountains blew chilly blasts upon us, and made us call out all the warm things we possessed—I say notwithstanding all this, we reached the Gulf of St. Lawrence in safety, and I do not think that a merrier or a happier crew ever crossed the Atlantic.