Chapter 3

Messrs. Russell & Co., Greenock and Port Glasgow, show at the Glasgow exhibition a very numerous and varied show of sailing models. First, we find the noble four-masted ships of from 1,800 tons to 2,200 tons, which sail and carry well on their tonnage, and which are worked by fewer hands than are required for a ship of the same burden with three masts but squarer yards. Some owners prefer the latter, and so Messrs. Russell show not only such handsome specimens as the four-masted Falls of Earn, but also the three-masted Ardencraig and Soudan. One of the favorite models of this firm is that of their 1,500 ton ship with three masts, represented by the Cromartyshire, of which type they have built a large number of vessels noted alike for their carrying capacity and their excellent sailing qualities. The Main, built for Mr. James Nourse, of London, is a good specimen of their 1,700 ton ship, as designed for the special trade of the owner, between Calcutta, Demerara, and London. Their 1,300 ton bark is represented by the model of the Aboukir Bay and her sisters of the Bay Line, owned by Messrs. Hatfield, Cameron & Co., of Glasgow; while their 1,000 ton barks are shown in the model of the Banca, belonging to Messrs. P. Denniston & Co., of the same city. These are about the smallest class of sailing ships built during recent years, the demands of the shipping trade being such as to make it unprofitable to sail anything smaller than about 1,500 tons; while the tendency is to exceed 2,000 tons in burden, and to reach even as high as 3,000 tons.--_The Engineer._

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WATER BLAST PUMP.

It is well known that the principle which is applied to the construction of vacuum or filter pumps, and which aims at the production of rarefied air in a certain inclosed space, may also be applied to the production of air _pressure_.

A simple apparatus by which this may be accomplished has recently been constructed by A. Beutell.

A tall cylindrical flask, K (see cut), is provided with an outlet tube near the bottom, and its stopper carries two tubes, one (M) for the entrance of a jet of water, and the other (L) for the exit of the compressed air, which may be conducted to a blast lamp or wherever air under pressure may be needed. The column of water entering through M causes air to be sucked in through the little hole at c, and this air, after arriving in the flask, is gradually compressed by the continuously entering water.

In order that the apparatus may work properly, it is necessary to construct the tube, M, in a particular manner, and of certain definite proportions. Fig. 3 exhibits its bore and shape in an enlarged view. A short distance below the orifice of the tube it is slightly expanded, and then gradually contracts to the place, b. It then again expands to an oblong cavity, and contracts again to a neck, e, which is a trifle wider than that at b, and which must be so situated that the column of water passing through b is exactly perpendicular to the center of the aperture at e. The tube then expands again to its original diameter, and is slightly curved, which is done to prevent any of the compressed air in the cylinder, K, from regurgitating upward.

The outlet tube at A is preferably constructed as shown in Fig. 2. Instead of being made of one piece, it is there represented as consisting of two pieces joined together by rubber tubing, a sort of check valve, G, being introduced into the rubber joint. By regulating the check valve, that is by approaching it more or less to the exit of the tube, A, the outflow of water may be regulated. It is important to adjust this so that the cylindrical flask will always be at least half full, and never over three-fourths filled. While the column of water falls through the aperture at b, into the expanded portion of M, it aspirates air through the little orifice, c, communicating with the outer air, and this air is carried along with it into the flask, where it accumulates until it is under a pressure equal to that of the column of water entering the apparatus, when the latter will cease to flow. By allowing the air to escape through L, more will be successively compressed, so that a steady blast may be obtained.

The proportions between the diameters of the expanded and contracted portions of the glass tube, M, are important. If the bore at b amounts to 2.5 millimeters, that at e should be 3 millimeters. Under these circumstances, and with a pressure of water equal to a column of 61.7 cubic centimeters, the apparatus will furnish 890 liters of air for every 1,000 liters of water consumed. If the two diameters were: b, 1 millimeter, and e, 2.4 mm., one liter of water aspirates 2.35 liters of air. These proportions are, no doubt, capable of improvement.--_Chem. Zeit. and Ch. Centralbl._

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TRANSMISSION OF POWER BETWEEN BODIES MOVING AT DIFFERENT VELOCITIES.

A few months ago there was exhibited, in the society's reading room, a working model of an application to railway working of what the inventor calls "division of the mass." In causing a body, moving at a high velocity, to communicate motion to another at rest, or moving at a lower velocity, he splits one of them up into parts all the more numerous, and therefore tenuous, as the difference in velocity is greater; and this is accomplished by causing one of the parts to take the form of a brush composed of metal fibers.

In applying this principle to the transmission of motion for driving machinery, a disk, fitted with segmental brushes, is slid laterally along the shaft, so that the fibers come into contact with radial projections on a second disk; and, although the contact is made instantaneously, the action is exerted gradually, owing to the flexibility of the fibers. That is to say, the full power is communicated without any shock.

A similar arrangement, but with one of the disks fixed, serves as a brake for arresting motion, and this again without shock, but with gradually increasing action. Where space is very much circumscribed, the clutch and the brake may be combined, by fitting a disk with brushes on one side, and projections on the other, so that it may be brought by a lever against a second disk, for transmitting motion, and against a third, fixed, for stopping it.

Safety appliances for arresting the descent of mine cages, in the event of the rope breaking, have hitherto depended upon the entrance of claws into the guides, or the clipping of the latter, or the wedging of the cage between the guides.

In this application of the system, the guides of the shaft are fitted with corrugated iron plates, and the sides of the cage with steel brushes. In the normal state of working, the brushes are kept clear of the guides, but, should the rope break, a small brush, fitted on a sector, constantly rubbing against the corrugations of the guides, aided by a spring or counterweight, brings the main brushes into contact with the guides by a link arrangement, like that of the parallel ruler, thus arresting the cage, and holding it suspended until the brushes are gradually relaxed, for "braking" the cage slowly down to the next landing.

Many attempts have been made to cause a locomotive, running at full speed, to exert such a mechanical action as would set a signal to danger, so as to protect the train from another following in the rear. By fitting the engine with a steel brush, attached to the axle boxes, so as to preserve a uniform height with respect to the rails, a stationary lever may be gradually moved, so that the signal is set at "danger" without shock. Moreover, by means of another brush, in the event of the engine being turned upon the wrong line, a lever may be made to shut off the steam, apply the brakes, blow the whistle, or move an index on a dial, recording a neglect of duty, or may exert these four actions simultaneously.

All the above applications of this principle--"the division of the mass"--have been tested experimentally, the last named by the model above referred to. The clutch arrangement has transmitted six horse power from a petroleum motor, making 200 revolutions a minute, to a dynamo making 2,000 revolutions, while applications to industrial purposes are now being made, both in this country and in Belgium. The inventor of the system is M. Raymond Snyers, Ingénieur des Mines, du Génie Civil, et des Arts et Manufactures, of the Louvain University.--_Journal of the Society of Arts._

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STEAM GENERATOR OF SERPOLLET BROTHERS, PRODUCING STEAM INSTANTANEOUSLY.

The explosibility of a steam generator may be measured by the relation of its total capacity to its vaporizing power. The old fashioned generators and some of the modern ones are so constructed as to contain from fifteen to twenty times more water than they are able to vaporize within one hour. Thus a great quantity of heat is obtained and a uniform pressure assured, but the steam-generating apparatus is costly, heavy, and cumbersome; it requires a long time before the necessary pressure is obtained, and the generator is only suitable for a stationary installation and where it can uninterruptedly work for a long period of time. Besides, the enormous quantity of hot water under pressure constitutes a constant danger, and the explosion of a steam generator with boiler tubes becomes a real disaster.

In order to satisfy the requirements which have newly arisen in connection with navigation, locomotion, small motors and apparatus which need for their working an intermittent supply of steam, it became necessary to modify the construction of steam boilers, to augment their heating surface, to diminish their residue of water, and to gradually construct so-called _inexplosible_ apparatus, of which the Belleville boiler forms one of the most characteristic prototypes.

In trying to reduce the inexplosibility to the utmost, Messrs. Serpollet Brothers have succeeded in constructing a type of boilers which may be called _absolutely inexplosible_, and this result has been obtained by reducing the capacity of the boiler to practically _nil_, thus rendering the explosibility also _nil_, for under the circumstances the relation between capacity and vaporizing power becomes itself _nil_.

The method employed for this purpose by Messrs. Serpollet is an extremely simple one. A cylindrical steel tube of convenient diameter and sufficient thickness is rolled flat at a temperature below the white heat of the metal, and the last touch of the rollers is given to it when already cold. By this means a flat tube is obtained, the empty interior space of which looks in a cross section (Fig. 1, No. 2) like a black line not thicker than a hair, and measures from 0.1 to 0.3 millimeter. This tube is finally rolled up in the form of a spiral, or left straight, according to the use to be made of it, and put into an appropriate furnace (Fig. 1, No. 1). To either end of the tube a joint is attached, the one for the purpose of admitting the water, the other for admitting the steam.

When under these circumstances the tube has been heated to a high temperature in a convenient fire box, the water which has been pumped into it, by a feed pump fastened to one of its extremities, is instantly changed into steam and escapes at the other end at a pressure and in a state of dryness depending on the working conditions of the apparatus. The ingenious and really original and novel idea in this invention is this flattened tube, which constitutes an actual capillary boiler inside of which the water squeezed in between its walls cannot assume its spheroidal state, and the formation of drops becomes absolutely impossible. There exists no longer a residue of hot water, nor are water gauges, safety valves, or any other of those numerous accessories required which make all steam boilers so complicated and which augment considerably their cost.

It also becomes unnecessary to connect the joint from which the steam escapes by means of a valve with the motor for which the steam is to be used. If the supply of steam is to be stopped, this can be done by simply suppressing the supply of water, i.e., by _emptying the boiler_.

The regular working is assured by the quantity of heat contained in the heated iron tube, to which, for this purpose, an intentionally great thickness has been given, and it is this heat of the iron which replaces the heat furnished by the hot water in the steam generators with boiler tubes. From the above it will be easy to understand the general arrangement of the new steam generator, when connected with its motor. This motor works a small intermitting pump, which supplies the capillary boiler with water, according to the quantity consumed. The machine is started by means of a small special pump worked by hand.

Whenever the velocity of the motor tends to increase, a centrifugal regulator placed upon the motor reduces the action of the pump and, consequently, the supply of water to the tube, thus checking the velocity of the machine. If the velocity tends to slacken, the inverse process is employed. In order to stop the machine, it suffices to turn off the water furnished by the pump by means of a three-way cock, and to send the water back to the reservoir of supply. The boiler can be emptied in less than a second, and the motor stops in consequence of being deprived of motive power.

The whole is marvelously simple, and creates astonishment and admiration in the mind of even the most skeptical persons who see the apparatus.

The boiler of the one horse power type weighs 33 kilogrammes. It consists of an iron tube having a length of 2 meters and a height of 10.5 centimeters after it has been flattened; the total heating surface thus obtained being 48 square centimeters. The power of vaporization amounts to 20 kilogrammes of water per hour, while the quantity of coal consumed during the same period amounts to only 4 kilogrammes, which is comparatively little for a boiler of so small a power.

Fig. 2 shows the first model of a tricycle constructed by Messrs. Serpollet as an application of their boiler for locomotion. The writer has seen the working of this apparatus, and consequently is able to give some data. The total weight of the machine is 185 kilogrammes, or about 250 kilogrammes when mounted by a person. The boiler is placed behind the tricycle, the motor is under the seat, inside of which is the water reservoir and the supply of coal. In the motor employed in the present case the feed pump is a constant supply pump, but by means of a directing lever turning around its own axis and acting upon a three-way cock, the water can be divided into two streams, the one emptying into the feeding reservoir, the other into the boiler. By varying the position of the cock, the power of the machine can be modified and its velocity regulated. The machine can be brought to a stop within less than two meters by means of the combined action of a brake and the complete suppression of water in the boiler. In order to start the machine, the water is sent into the tube by a little extra pump worked for a moment by the left hand of the cyclist when starting.

On July 25 some experiments were made before the Society of Civil Engineers with the tricycle above described, and on that occasion it traversed the Rue Girardon and the Rue de Norvino to Montmartre (streets in which the gradient rises to 15 centimeters per meter) with a velocity of three meters per second.

Fig. 3 represents the arrangement of the first stationary boiler of the new kind. The letters of reference will suffice to indicate the position of the principal parts of it, the forms of which may be varied according to the object for which the boiler is to be used.

Messrs. Serpollet are occupied at present with studying the special arrangements which will be needed for connecting their boiler with a quadricycle, a torpedo boat, a stove, a locomotive, or a stationary machine of 10 horse power, and with rectangular parts.

The inexplosibility of their boiler has been tested during an experiment made before the engineers of mines, on which occasion a manometer (steam gauge) graduated for a pressure of upward 200 kilogrammes per square centimeter was used, and the pressure raised far beyond the limits indicated. The result was that the hand of the manometer, being pressed against the walls of the box, became bent, and though the boiler was submitted to a pressure the degree of which it was impossible to measure, it was not changed in the slightest.

Incrustation of the boiler is not to be feared, for, in consequence of the great velocity with which the steam circulates through the tube, the solid matter dissolved in the water becomes pulverized and is forced out, mechanically assisting to lubricate and polish the parts of the motor.

The invention of Messrs. Serpollet is still too new to foretell all its possible applications, but their apparatus, in its present form, is exactly the steam generator which will be useful for producing a small motive force; while it will be necessary to wait until it has been ascertained, by further study, how the system can economically be used for high motive power.

The most natural and immediate application of the invention seems to be its use for the electric lighting of restaurants, in which case one of the instantaneous vaporization tubes might be connected with stoves which remain lighted all day, and which might thus besides supply the necessary motive force to work a small dynamo charging some accumulators.--_E. Hospitalier, in La Nature._

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GAS LIGHTING BY HIGH-POWER BURNERS.

In the course of a communication presented to the Societe Industrielle du Nord de la France by the manager of the Wazemmes Gas Company, he made the following remarks on gas lighting with high-power burners:

For gas of a standard illuminating value, the lighting power increases with the temperature of the flame. It also increases, under favorable conditions, if the quantity of gas consumed by the burner in a certain period is augmented. Thus, two burners consuming 60 liters (rather more than 2 cubic feet) of gas, placed in juxtaposition, produce less light than one burner consuming 120 liters. As it is impossible to indefinitely increase the supply to ordinary burners, multiple-flame burners have been invented, in which two or more ordinary flames are united so that they may impinge upon each other. By an ingenious arrangement for bringing the air into contact with the multiple flames, two excellent types of lamps are obtained, consuming respectively 700 and 1,400 liters per hour, which meet with a rapid demand in Paris, and in many other towns, for lighting wide public thoroughfares, squares, and large open spaces. If, however, it is desired to obtain a flame with a much higher temperature, it is necessary to resort to a special arrangement for heating the air intended for combustion with the gas. The principle of heating the air by means of waste heat escaping with the products of the waste gas--the regenerative principle--was adopted by Mr. F. Siemens, and applied not only to gas burners, but to high temperature stoves. With the Siemens burner on the regenerative principle the following results are obtained: With a consumption of 150 liters per hour, the light of from 1 to 3 carcels; 250 to 300 liters, 6 to 7 carcels; 600 liters, 15 carcels; 800 liters, 20 to 22 carcels; 1,600 liters, 46 to 48 carcels; 2,200 liters, 72 carcels. Unfortunately, the construction of the Siemens Argand lamps is very delicate, and, moreover, they have the disadvantage of being heavy and rather unsightly. In Germany they have been widely adopted; but in France they have met with but little success. The Schulke lamp is made on the same principle; and this appears to be too delicate to come into general use. One of the latest burners of the regenerative class is the Wenham, which has been before the public for some time in England and is now being adopted in France. In point of fact it is merely a very effective improvement on Breittmayer's burner, from which it differs only in its construction; being produced in some elegant styles, which lend themselves perfectly to the decorations of private houses. The No. 2 lamp of this type, with a consumption of 283 liters (10 cubic feet) per hour, has given 126 candles, in a vertical direction without reflectors: horizontally, 50 candles. But the gas employed in the tests had an illuminating power about 20 per cent. higher than that usual in Paris. When experimenting in Paris with a No. 3 lamp in a vertical direction, it showed a consumption of 34.6 liters (1.2 cubic feet) per carcel obtained. The Wenham lamp is constructed to give light in a vertical direction; and by adopting a large reflector, the illuminating power is increased 18 per cent. in a vertical line and 55 per cent. at 80°, which is a highly satisfactory result. There are at present five sizes of these lamps. There is also the Delmas hot air burner, in which the batswing flame is completely inclosed in a glass, mounted with a sheet-iron casing, heated by the products of combustion, through which the air passes on its passage downward to feed the flame; and it thus increases the temperature, improves the illuminating power, and produces a beautiful steady light. Mention also may be made of the Siemens radiated heat burner, by means of which the heating of the air is effected simply by the radiation of the metallic parts of the appliance which are in contact with the flame. These burners produce the light of 1 carcel (9.5 candles) with a gas consumption of 70 liters (about 2½ cubic feet), and are therefore, from an economical point of view, intermediary between the high power and regenerative burners. This degree of economy can be ascertained by an ingenious arrangement of the air supply in a burner with holes, which has been made in the laboratory of the Wazemmes Gas Company by M. Verlé, the engineer, who has invented a very simple burner called the "Lillois," with which the light of 1 carcel is obtained with a consumption of 70 liters. This produces a tulip-shaped flame, and it has a specially constructed glass arrangement on the outside for regulating the combustion. Comparing the above-mentioned burners with each other, we arrive at the following results: The "Lillois" burner consumes 70 liters of gas per carcel; the Siemens ordinary, 70 liters; the Siemens-Breittmayer, 35 to 39 liters; the Wenham, about 35 liters. Taking this into account, and considering that a carcel corresponds with 105 liters of gas consumed in the Bengal form of burner, we see that the economy in gas might, by employing these burners, reach from 33 to 71 per cent. If this is compared with the batswing burner, which produces the light of 1 carcel with a consumption of 120 liters of gas, the economy is greater--varying, according to the type of lamp, from 41 to 85 per cent.

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SYNCHRONIZING CLOCKS.