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parts of the camel, the water is pumped from them; by which means they rise, and raise the ship along with them. Each half of the camel is often about 127 feet in length; the breadth at one end is 22, and at the other 13. The hold is divided into several compartments, that the machine may be kept in equilibrio while the water is flowing into it. An East India ship that draws 15 feet of water can, by the help of the camel, be made to draw only 11; and the heaviest ships of war, of 90 or 100 guns, can be so lightened as to pass, without obstruction, all the sand-banks of the Zuyder-Zee.

Leupold, in chap. 6. of his Theatrum Machinarum, published in 1725, at Leipsick, describes this machine under the head Beschreibung der se genannten Camele zu Amsterdam, womit die befruchten Schiffe über dem Pampus gebracht werden, and says it was invented by Cornelius Meyer, a Dutch engineer. But the Dutch writers almost unanimously ascribe this invention to a citizen of Amsterdam, called Meuves Meindertszoon Bakker.

As ships built in the Neiva cannot be conveyed into harbour, on account of the sand-banks formed by the current of that river, camels are employed also by the Russians, to carry ships over these shoals: and they have them of various sizes. Bernoulli saw one, each half of which was 217 feet long, and 36 broad. Camels are used likewise at Venice. An engraving of the camel may be seen in L'Art de bater les Vaisseaux, Amsterdam, 1719, 4to. vol. ii. p. 93.

CANALS, motion of water in. See STREAM.

CAPSTAN, a large massy column, shaped like a truncated cone, placed perpendicularly on the deck of a ship, and turned by levers or bars, which pass through holes pierced in its upper extremity; serving, by means of a cable which winds round the barrel, to draw up burdens fastened to the end of the cable. The power of this machine in its simplest state is manifestly reducible to that of the axis in peritrochio. There is frequently attached to it a tackle of pulleys, but the ingenious contrivance described in art. 4. of the introductory part of this volume is far preferable.

CASKS, manufactory of. This is now much facilitated by means of the machinery for the invention of which Messrs. Plaskete and Brown took out a patent in March 1811.

The machinery described in the specification of this patent is of the various kinds following, according to the-work which it is intended to execute.

First-The machinery for cutting out the stave, consists of a stout bench, having a board or platform annexed to it, capable of being moved endways, to which another board is connected,

so arranged as to be moved across it steadily by racks and pinions, or screws. This last board has a hollow part made in it, in which the stave-board may be laid, so that one edge of it may project clear beyond the edge of the first mentioned board: a circular saw is placed either above or below the bench, having its axis at right angles to the line of motion of the first mentioned board, and opposed to the direction of the course of the projecting part of the stave-board: this circular saw is made flat, when straight edged staves are to be cut, and is dished, or of a spherical shape, when staves with curved edges are wanted.

The board first mentioned is moved either in a right line, or is made to assume a curved course by being confined in its motion by curved grooves, or by curved rods moving against pins; and by the proper management of these sliding-boards, the stave-board is cut by the circular saw of the shape desired. The machinery next used consists of a large lathe, in which the cask is turned in a vertical position when it is of a large size, (after it is formed in the usual manner from the staves prepared as above described) being either fixed in a great chuck placed beneath it, or in a cylindrical cage, which surrounds it, fixed upon a strong upright arbor, and revolving between collars, where it serves the office of a mandril. In this lathe the chime and groove for receiving the head are turned in the cask by the application of a proper tool. When the cask is small, the cage is made to turn in a horizontal position, instead of revolving vertically.

The third operation is to form the head, which is pinned together as usual, after having the pin-holes made by piercers, projecting from the mandril of a lathe; the distances and depth of which holes are correctly regulated by gauges; it is then turned on a flat revolving table, from which pomts project to hold it fast, and against which it is held by another revolving piece, that is screwed towards the first, where it is brought to the proper size of the cask by fit tools.

The fourth operation is to turn the whole cask at the outside; for which purpose it is placed in a large lathe between two chucks, made to fit into the chimes, and attached to the head by points: and then the surface of the cask is turned smooth by a spoke-shave, or other fit instrument, held against it by a rest properly placed for the purpose.

The patentees bend the wooden hoops for their casks in a more expeditious manner, by fastening one end of them to the circumference of a wheel, and pressing them against the wheel as it is turned round: they also describe a method of forming the projecting part in the bung-staves of the small casks, called

bottles, by flat or concave circular saws, which cut the face of the stave on each side close up to the projection: and lastly, they state, that in giving motion to their machinery they use any of the usual first movers and mill-work, as may be necessary. (Retrospect, No. 31.)

CELLAR CRANE, a machine represented in fig. 6. pl. VI.; and is very useful to wine-merchants, brewers, &c. in drawing up and letting down casks full of wine, beer, &c. It saves the trouble and inconvenience of horses, and in many places can be used where horses could not. AA are two wooden props, about 6 feet in height, and jointed together like a ruler at B. They are connected to each other by an iron round bar c, and wooden bar at the bottom D. The iron prongs EE fasten the uprights steadily to the edge of the cellar; F is the axis round which two ropes are coiled, the ends of which are fastened to the two clamps GG. On the axis F is fixed the iron wheel H, of 3 feet in diameter: in the teeth of this works the pinion 1, of about 6 or 7 inches in diameter, and is turned by the handle at K.

It is evident, by a bare inspection of the figure, that when the two ropes are slipt over the ends upon the barrel, either at the top or bottom of the cellar, by turning of the winch K towards or from the operator, the barrel can be safely and expeditiously taken out or lowered down. When 'the crane is done with it shuts up, by unscrewing the nut B, taking the wheel and axis away out of the loops at L, and folding the sides at a together, like a jointed rule; it may then be taken away in the cart or dray, or taken in the men's hands.

CENTRIFUGAL PUMP, a very curious machine, invented by Mr. Erskine, for raising water by means of a centrifugal force combined with the pressure of the atmosphere. It consists of a large tube of copper, &c. in the form of a cross, which is placed perpendicularly in the water, and rests at the bottom on a pivot. At the upper part of the tube is an horizontal cog-wheel, which touches the cogs of another in a vertical position; so that by the help of a double winch the whole machine is moved round with very great velocity. Near the bottom of the perpendicular part of the tube is a valve opening upwards; and near the two extremities, but on the contrary side of the arms or cross part of the tube, are two other valves opening outwards. These two valves are, by the assistance of springs, kept shut till the machine is put in motion, when the centrifugal velocity of the water forces them open, and discharges itself into a cistern or reservoir placed there for that purpose. On the upper part of the arms are two holes, which are closed by pieces screwed into the metal of the tube. Before the machine can work, those holes must be opened, and

water poured in through them, till the whole tube be full; by these means all the air will be forced out of the machine, and the water supported in the tube by means of the valve at the bottom. The tube being thus filled with water, and the holes closed by the screw-caps, it is turned round by means of the winch, when the water in the arms of the tube acquires a centrifugal force, opens the valves near the extremities of the arms, and flies out with a velocity nearly equal to that of the extremities of the said arms. The theory of this pump may be seen in arts. 537, 538, of our first volume.

CHIMNEY CLEANSING MACHINES have been lately invented, in order, as far as possible, to diminish the number of infant victims of a filthy and disgusting operation, performed under the inspection of unfeeling masters. Those who have long viewed the wretchedness to which many of the children are exposed who are still employed in climbing chimneys, will be happy to hear of any contrivances which have a tendency to lessen their sufferings: we therefore mention here two machines which have been devised for the purpose of sweeping chimneys; either of which may, we doubt not, be made use of with considerable success.

The first is that invented by Mr. George Smart, of Ordnancewharf, Westminster-bridge. Its principal parts are the brush, the rods for raising the brush, and the cord for connecting the whole together. The brush consists of four fan-shaped or wing-like portions, which are hung upon hinges, in order that in ascending the chimney the brush may take up as little space as possible, and in descending may spread out and sweep the sides of the flue: this brush is prevented from falling down into its contracted form by a contrivance exactly like that which is made use of for umbrellas. The substance made use of in general for the brush is what is called whisk. The rods are hollow tubes, with a metal socket at the lower end; some of the sockets have screws in them, for the purpose of confining the cord, and preventing the rods from separating. The upper ends of the rods are now made without ferrules, aud are rather tapered, which allows of a small motion within the sockets. Each rod is about 2 feet long. The cord runs from the top of the brush through all the rods, and when drawn tight keeps the whole of the machine together.

Method of using the machine. Having first ascertained, by looking up the chimney, what course the flue immediately takes, the cloth is then to be fixed before the fire-place, with the horizontal bar, and the sides to be closed with two upright bars. The next part of the operation is to introduce, through the opening in the cloth, the brush in its contracted form: this

opening is then to be buttoned or tied up, to prevent the soot coming into the apartments; then one of the rods is to be passed up the cord into the socket, on the lower end of the rod which supports the brush; the other rods are in like manner, one by one in succession, to be brought up, until the brush is raised somewhat above the top of the chimney, observing to keep the cord constantly tight; and when those rods which have a screw in the socket are brought up they are to be placed on the purchase, when the cord is to be put round the pulley and drawn very tight, and screwed down, by which all the rods above will be firmly connected together, and the whole may be considered one long flexible rod.

When the operator thinks that the brush is near the top of the chimney he should move it up and down, as he will then find the brush, if out, stop, in returning, on the top of the pot or chimney.

When it is known to be out, the machine is to be pulled down: in doing which the edges of the brush, striking against the top of the chimney, will cause it to expand; and there being a spring to prevent its contracting again, it will sweep the soot down before it: the whisk being long and elastic, makes the brush capable of filling flues of different diameters. In drawing down the machine the person should grasp with his left hand the rod immediately above that which he is separating with his right hand, otherwise he may chance to have those above loosen and slide down the cord, which will render the operation unpleasant and difficult: the rods, as they are brought down, are to be laid carefully one by one in as small a compass as they conveniently can be, that they may not dirt the apartments: with a little attention they may be placed like a bundle of sticks, side by side, in very little compass. When the brush is quite down it is to be shaken withinside the cloth, then the spring must be pushed in, and the brush which was expanded will flap down into the state in which it went up.

If, as sometimes happens, there is any difficulty found in drawing the brush into the upper part of the chimney, the rods must be thrust up again somewhat higher, in order to alter the direction, then carefully drawn down. It will be proper to let the cloth remain a short time up (where great cleanliness is required), in order to let the finer particles of soot subside within it.

For extinguishing a chimney on fire a coarse cloth is to be tied over the brush and dipped into water, then passed up as above directed.

It is now more than ten years since this machine was invented, and its use has been attended with very considerable success;

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