Chapter 4

The need of irrigating prairies, inundating vines, drying marshes, and accumulating electricity cheaply has, for some time past, led to a search for some means of utilizing the forces of nature better than has ever hitherto been done. Wind, which figures in the first rank as a force, has thus far, with all the mills known to us, rendered services that are much inferior to those that we have a right to expect from it with improved apparatus; for the work produced, whatever the velocity of the wind, has never been greater than that that could be effected by wind of seven meters per second. But, thanks to the experiments of recent years, we are now obtaining an effective performance double that which we did with apparatus on the old system.

Desirous of making known the efforts that have been made in this direction, we lately described Mr. Dumont's atmospheric turbine. In speaking of this apparatus we stated that aerial motors generally stop or are destroyed in high winds. Recently, Mr. Sanderson has communicated to us the result of some experiments that he has been making for years back by means of an apparatus which he styles a pantanemone.

The engraving that we give of this machine shows merely a cabinet model of it; and it goes without saying that it is simply designed to exhibit the principle upon which its construction is based.

Two plane surfaces in the form of semicircles are mounted at right angles to each other upon a horizontal shaft, and at an angle of 45° with respect to the latter. It results from this that the apparatus will operate (even without being set) whatever be the direction of the wind, except when it blows perpendicularly upon the axle, thus permitting (owing to the impossibility of reducing the surfaces) of three-score days more work per year being obtained than can be with other mills. Three distinct apparatus have been successively constructed. The first of these has been running for nine years in the vicinity of Poissy, where it lifts about 40,000 liters of water to a height of 20 meters every 24 hours, in a wind of a velocity of from 7 to 8 meters per second. The second raises about 150,000 liters of water to the Villejuif reservoir, at a height of 10 meters, every 24 hours, in a wind of from 5 to 6 meters. The third supplies the laboratory of the Montsouris observatory.

The first is not directible, the second may be directed by hand, and the third is directed automatically. These three machines defied the hurricane of the 26th of last January.--_La Nature._

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RELVAS'S NEW LIFE-BOAT.

The Spanish and Portuguese papers have recently made known some interesting experiments that have been made by Mr. Carlos Relvas with a new life-boat which parts the waves with great facility and exhibits remarkable stability. This boat, which is shown in front view in one of the corners of our engraving, is T-shaped, and consists of a very thin keel connected with the side-timbers by iron rods. Cushions of cork and canvas are adapted to the upper part, and, when the boat is on the sea, it has the appearance of an ordinary canoe, although, as may be seen, it differs essentially therefrom in the submerged part. When the sea is heavy, says Mr. Relvas, and the high waves are tumbling over each other, they pass over my boat, and are powerless to capsize it. My boat clears waves that others are obliged to recoil before. It has the advantage of being able to move forward, whatever be the fury of the sea, and is capable, besides, of approaching rocks without any danger of its being broken.

Fig. 1 represents a single barrel fitted with sights and firmly attached to a heavy block of beech. This was placed on an ordinary rifle rest, being fastened thereto by a pin at the corner, A, the block and barrel being free to revolve upon the pin as a center. Several shots were fired both with the pin in position and with it removed, the barrel being carefully pointed at the target each time. No practical difference in the accuracy of fire was discernible under either condition. When the pin was holding the corner of the block, the recoil caused the barrel to move from right to left in a circular path; but when the pin was removed, so that the block was not attached to the rest in any way, the recoil took place in a line with the axis of the bore. It will be observed that the conditions which are present when a double barreled gun is fired in the ordinary way from the shoulder were in some respects much exaggerated in the apparatus, for the pin was a distance of 3 in. laterally from the axis of the barrel, whereas the center of resistance of the stock of a gun against the shoulder would ordinarily be about one-sixth of this distance from the axis of the barrel. This experiment would apparently tend to prove that the recoil does not appreciably affect the path of the projectile, as it would seem that the latter must clear the muzzle before any considerable movement of the barrel takes place.

With a view to obtain a further confirmation of the result of this experiment, it was repeated in a different form by a number of shots being fired from a "cross-eyed" rifle,[1] in which the sights were fixed in the center of the rib. Very accurate shooting was obtained with this arm.

[Footnote 1: A cross-eyed rifle is one made with a crooked stock for the purpose of shooting from the right shoulder, aim being taken with the left eye.]

A second theory, often broached, in order to account for the divergence of the charge, is that the barrel which is not being fired, by its _vis inertia_ in some way causes the shot to diverge. In order to test this, Mr. Phillips took a single rifle and secured it near the muzzle to a heavy block of metal, when the accuracy of the shooting was in no way impaired.

So far the experiments were of a negative character, and the next step was made with a view to discover the actual cause of the divergence referred to. A single barrel was now taken, to which a template was fitted, in order to record its exact length. The barrel was then subjected to a heavy internal hydrostatic pressure. Under this treatment it expanded circumferentially and at the same time was reduced in length. This, it was considered, gave a clew to the solution of the problem. A pair of barrels was now taken and a template fitted accurately to the side of the right-hand one. As the template fitted the barrel when the latter was not subject to internal pressure, upon such pressure being applied any alterations that might ensue in the length or contour of the barrel could be duly noted. The right-hand barrel was then subjected to internal hydrostatic pressure. The result is shown in an exaggerated form in Fig. 2. It will be seen that both barrels are bent into an arched form. This would be caused by the barrel under pressure becoming extended circumferentially, and thereby reduced in length, because the metal that is required to supply the increased circumference is taken to some extent from the length, although the substance of metal in the walls of the barrel by its expansion contributes also to the increased diameter. A simple illustration of this effect is supplied by subjecting an India-rubber tube to internal pressure. Supposing the material to be sufficiently elastic and the pressure strong enough, the tube would ultimately assume a spherical form. It is a well known fact that heavy barrels with light charges give less divergence than light barrels with heavy charges.

After the above experiments it was hoped that, if a pair of barrels were put together parallel and soldered only for a space of 3 in. at the breech end, and were then coupled by two encircling rings joined together as in Fig. 4, the left-hand ring only being soldered to the barrel, very accurate shooting would be obtained. For, it was argued, that by these means the barrel under fire would be able to contract without affecting or being affected by the other barrel; that on the right-hand, it will be seen by the illustration, was the one to slide in its ring.

A pair of able 0.500 bore express rifle barrels were accordingly fitted in this way. Fig. 3 shows the arrangement with the rings in position. Upon firing these barrels with ordinary express charges it was found that the lines of fire from each barrel respectively crossed each other, the bullet from the right-hand barrel striking the target 10 in. to the left of the bull's eye, while the left barrel placed its projectile a similar distance in the opposite direction; or, as would be technically said, the barrels crossed 20 in. at 100 yards, the latter distance being the range at which the experiment was made. These last results have been accounted for in the following manner: The two barrels were rigidly joined for a space of 3 in., and for that distance they would behave in a manner similar to that illustrated in Fig. 2, and were they not coupled at the muzzles by the connecting rings they would shoot very wide, the charges taking diverging courses. When the connecting rings are fitted on, the barrel not being fired will remain practically straight, and, as it is coupled to the barrel being fired by the rings, the muzzle of the latter will be restrained from pointing outward.

The result will be as shown in an exaggerated manner by the dotted lines on the right barrel in Fig. 3.

It would appear from these experiments that when very accurate shooting is required at long ranges with double-barreled rifles, they should be mounted in a manner similar to that adopted in the manufacture of the Nordenfelt machine gun, in which weapon the barrels are fitted into a plate at the extreme breech end, the muzzles projecting through holes bored to receive them in a metal plate. No unequal expansion would then take place, and the barrels would be free to become shorter independently of each other. We give the above experiments on the authority of their author, who, we believe, has taken great pains to render them as exhaustive as possible, so far as they go.--_Engineering._

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BALL TURNING MACHINE.

The distinguishing feature in the ball turning machine shown opposite is that the tool is stationary, while the work revolves in two directions simultaneously. In the case of an ordinary spherical object, such as brass clack ball, the casting is made from a perfect pattern having two small caps or shanks, in which the centers are also marked to avoid centering by hand. It is fixed in the machine between two centers carried on a face plate or chuck, with which they revolve. One of these centers, when the machine is in motion, receives a continuous rotary motion about its axis from a wormwheel, D. This is driven by a worm, C, carried on a shaft at the back of the chuck, and driven itself by a wormwheel, B, which gears with a screw which rides loosely upon the mandrel, and is kept from rotating by a finger on the headstock. This center, in its rotation, carries with it the ball, which is thus slowly moved round an axis parallel to the face plate, at the same time that it revolves about the axis of the mandrel, the result being that the tool cuts upon the ball a scroll, of which each convolution is approximately a circle, and lies in a plane parallel to the line of centers.

When the chuck is set for one size of ball, which may be done in a few minutes, any quantity of that diameter may be turned without further adjustment. A roughing cut for a 2 in. ball may be done in one minute, and a finishing cut leaving the ball quite bright in the same time. The two paps are cut off within one-sixteenth of an inch and then broken off, and the ball finished in the usual way. On account of the work being geometrically true, the finishing by the ferrule tool is done in one quarter of the time usually required.

The chuck may be applied to an ordinary lathe or may be combined with a special machine tool, as show in our illustration. In the latter case everything is arranged in the most handy way for rapid working, and six brass balls of 2 in. in diameter can be turned and finished in an hour. The machine is specially adapted for turning ball valves for pumps, pulsometers, and the like, and in the larger sizes for turning governor balls and spherical nuts for armor plates, and is manufactured by Messrs. Wilkinson and Lister, of Bradford Road Iron Works, Keighley.--_Engineering._

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COOLING APPARATUS FOR INJECTION WATER.

It often happens in towns and where manufactories are crowded together, that the supply of water for condensing purposes is very small, and consequently that it attains an inconveniently high temperature under unfavorable conditions of weather, resulting in the deterioration of the vacuum and a consequent increase in the consumption of fuel. To remedy or to diminish this difficulty, Messrs. Boase and Miller, of London, have brought out the water cooler illustrated above. This consists, says _Engineering_, of a revolving basket of wire gauze surrounding an inner stationary vessel pierced with numerous small holes, through which the heated water discharged by the air pump finds its way into the basket, to be thrown out in the form of fine spray to a distance of 20 ft. at each side. The drops are received in the tank or pond, and in their rapid passage through the air are sufficiently cooled to be again injected into the condenser.

The illustration shows a cooler having a basket three feet in diameter, revolving at 300 revolutions per minute, and discharging into a tank 40 ft. square. It requires 3 to 4 indicated horse-power to drive it, and will cool 300 gallons per minute. The following decrease of temperature has been observed in actual practice: Water entering at 95 deg. fell 20 deg. in temperature; water entering at 100 deg. to 110 deg. fell 25 deg.; and water entering at 110 deg. to 120 deg. fell 30 deg. The machine with which these trials were made was so placed that the top of the basket was four ft. from the surface of the water in the pond. With a greater elevation, as shown in the engraving, better results can be obtained.

The advantages claimed for the cooler are that by its means the temperature of the injection water can be reduced, the cost and size of cooling ponds can be diminished, and condensing engines can be employed where hitherto they have not been possible. The apparatus has been for two years in operation at several large factories, and there is every reason to believe that its use will extend, as it supplies a real want in a very simple and ingenious manner. Messrs. Duncan Brothers, of Dundee and 32 Queen Victoria Street, E.C., are the manufacturers.

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CORRUGATED DISK PULLEYS.

This is a pulley recently introduced by Messrs. J. and E. Hall, of Dartford Eng. With the exception of the boss, which is cast, it is composed entirely of steel or sheet iron. In place of the usual arms a continuous web of corrugated sheet metal connects the boss to the rim; this web is attached to the boss by means of Spence's metal. Inside the rim, which is flanged inward, a double hoop iron ring is fixed for strengthening purposes. The advantageous disposition of metal obtained by means of the corrugated web enables the pulley to be made of a given strength with less weight of material, and from this cause and also on account of being accurately balanced these pulleys are well adapted for high speeds.

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[KANSAS CITY REVIEW.]

EARLY HISTORY OF THE TELEGRAPH.

Although the electric telegraph is, comparatively speaking, a recent invention, yet methods of communication at a distance, by means of signals, have probably existed in all ages and in all nations. There is reason to believe that among the Greeks a system of telegraphy was in use, as the burning of Troy was certainly known in Greece very soon after it happened, and before any person had returned from Troy. Polybius names the different instruments used by the ancients for communicating information--"pyrsia," because the signals were always made by means of fire lights. At first they communicated information of events in an imperfect manner, but a new method was invented by Cleoxenus, which was much improved by Polybius, as he himself informs us, and which may be described as follows:

Take the letters of the alphabet and arrange them on a board in five columns, each column containing five letters; then the man who signals would hold up with his left hand a number of torches which would represent the number of the column from which the letter is to be taken, and with his right hand a number of torches that will represent the particular letter in that column that is to be taken. It is thus easy to understand how the letters of a short sentence are communicated from station to station as far as required. This is the pyrsia or telegraph of Polybius.

It seems that the Romans had a method of telegraphing in their walled cities, either by a hollow formed in the masonry, or by a tube fixed thereto so as to confine the sound, in order to convey information to any part they liked. This method of communicating is in the present age frequently employed in the well known speaking tubes. It does not appear that the moderns had thought of such a thing as a telegraph until 1661, when the Marquis of Worcester, in his "Century of Inventions," affirmed that he had discovered a method by which a man could hold discourse with his correspondent as far as they could reach, by night as well as by day; he did not, however, describe this invention.

Dr. Hooke delivered a discourse before the Royal Society in 1684, showing how to communicate at great distances. In this discourse he asserts the possibility of conveying intelligence from one place to another at a distance of 120 miles as rapidly as a man can write what he would have sent. He takes to his aid the then recent invention of the telescope, and explains how characters exposed at one station on the top of one hill may be made visible to the next station on the top of the next hill. He invented twenty-four simple characters, each formed of a combination of three deal boards, each character representing a letter by the use of cords; these characters were pushed from behind a screen and exposed, and then withdrawn behind the screen again. It was not, however, until the French revolution that the telegraph was applied to practical purposes; but about the end of 1703 telegraphic communication was established between Paris and the frontiers, and shortly afterward telegraphs were introduced into England.

The history of the invention and introduction of the electric telegraph by Prof. Morse is one of inexhaustible interest, and every incident relating to it is worthy of preservation. The incidents described below will be found of special interest. The article is from the pen of the late Judge Neilson Poe, and was the last paper written by him. He prepared it during his recent illness, the letter embodied in it from Mr. Latrobe being of course obtained at the time of its date. It is as follows:

On the 5th of April, 1843, when the monthly meeting of the directors of the Baltimore & Ohio Railroad Company was about to adjourn, the President, the Hon. Louis McLane, rose with a paper in his hand which he said he had almost overlooked, and which the Secretary would read. It proved to be an application from Prof. Morse for the privilege of laying the wires of his electric telegraph along the line of the railroad between Baltimore and Washington, and was accompanied by a communication from B.H. Latrobe, Esq., Chief Engineer, recommending the project as worthy of encouragement.

On motion of John Spear Nicholas, seconded by the Hon. John P. Kennedy, the following resolution was then considered:

_Resolved_, "That the President be authorized to afford Mr. Morse such facilities as may be requisite to give his invention a proper trial upon the Washington road, provided in his opinion and in that of the engineer it can be done without injury to the road and without embarrassment to the operations of the company, and provided Mr. Morse will concede to the company the use of the telegraph upon the road without expense, and reserving to the company the right of discontinuing the use if, _upon experiment_, it should prove _in any manner injurious_."

"Whatever," said Mr. McLane, "may be our individual opinions as to the feasibility of Mr. Morse's invention, it seems to me that it is our duty to concede to him the privilege he asks, and to lend him all the aid in our power, especially as the resolution carefully protects the company against all present or future injury to its works, and secures us the right of requiring its removal at any time."

[In view of the fact that no railroad can now be run safely without the aid of the telegraph, the cautious care with which the right to remove it if it should become a nuisance was reserved, strikes one at this day as nearly ludicrous.]

A short pause ensued, and the assent of the company was about to be assumed, when one of the older directors, famed for the vigilance with which he watched even the most trivial measure, begged to be heard.