and what is very remarkable, the same side of the feather will be constantly opposite the tube.

While the feather is flying before the smooth tube, it will be immediately attracted by an excited rough tube, or a stick of wax, and fly continually from one tube to the other, till the electricity of both is discharged.

This was one of the first, and is one of the most common experiments in electricity; it is, however, very entertaining, and shows the nature of electric attraction and repulsion altogether as well as a more elaborate performance.

The Marvellous Fountain.

Suspend a vessel of water from the middle of the brass arch, and place in the vessel a capillary syphon. The water will at first issue by drops only, from the lower leg of the syphon, but when the vessel is put in motion, there will be one continued stream of water, and if the electrification be strong, a number of streams will issue, in form of a cone, the top of which will be at the extremity of the tube. This experiment may be stopped and renewed, almost instantly, as if at the word of command.

The Magic Picture.

Have a large print, suppose of the king, with a frame and glass. Cut a panel out of the print at about two inches from the frame all round; with thin paste or gum, fix the border that is cut off, on the inside of the glass, pressing it smooth and close, then fill up the vacancy, by covering the glass well with leaf gold, or thin tin-foil, so that it may lie close. Cover, likewise, the inner edge of the bottom part of the back of the frame with the same tin-foil, and make a communication between that and the tin-foil in the middle of the glass; then put in the board, and that side is finished. Turn up the glass and cover the foreside with tin-foil, exactly over that on the backside, and when it is dry, paste over it the pannel of the print that was cut out, observing to bring the corresponding parts of

the border and pannel together, so that the picture will appear as at first, only part of it behind the glass, and part before. Lastly, hold the print horizontally by the top, and place a little moveable gilt crown on the king's head.

Now if the tin-foil on both sides of the glass be moderately electrified, and another person take hold of the bottom of the frame with one hand, so that his fingers touch the tin-foil, and with the other hand endeavour to take off the crown, he will receive a very smart blow, and fail in the attempt. The operator. who holds the frame by the upper end, where there is no tin-foil, feels nothing of the shock, and can touch the face of the king, without danger, which he pretends to be a test of his loyalty. When a ring of persons take a shock among them, the experiment is called the conspirators.

The Tantalian Cup.

Place a cup or pot, of any sort of metal, on a stool of baked wood, or a cake of wax. Fill to the brim with any sort of liquor; let it communicate with the branch by a small chain, and when it is moderately electrified, desire a person to taste the liquor, without touching the cup with his hands, and he will immediately receive a shock at his lips; which, however, should not be very strong.

The motion of the wheel being stopped, you offer to taste the liquor yourself, and desire the rest of the company to taste it likewise, which they will do without any inconvenience. You then give the signal to the operator, and while you are amusing the company with discourse, the cup is again charged, and you desire the same person a second time to taste the liquor, when, to the no small diversion of the company, he will receive a second shock.

The Self-moving Wheel.

This wheel is formed of a thin round plate of window-glass, 17 inches diameter, well gilt on both sides, all but two inches next the edge. Two small hemi

spheres of wood are then fixed with cement to the middle of the upper and under sides, centrally opposite, and in each of them a thick strong wire, eight or ten inches long, which together make the axis of the wheel. It turns horizontally, on a point at the lower end of its axis, which rests on a bit of brass cemented within a glass salt-cellar. The upper end of its axis passes through a hole in a thin brass plate, which keeps it six or eight inches distant from any non-electric, and has a small ball of wax or metal on the top, to keep in the fire.

In a circle on the table which supports the wheel, are fixed twelve small pillars of glass, at about eleven inches distance, with a thimble on the top of each. On the edge of the wheel is a small leaden bullet, communicating by a wire with the gildings of the upper surface of the wheel; and about six inches from it is another bullet, communicating, in like manner, with the under surface. When the wheel is to be charged by the upper surface, a communication must be made from the under surface to the table.

When it is well charged it begins to move. The bullet nearest to a pillar moves towards the thimble on that pillar, and passing by, electrifies it, and then pushes itself from it. The succeeding bullet, which communicates with the other surface of the glass, more strongly attracts that thimble, on account of it being electrified by the other bullet, and thus the wheel increases its motion, till it is regulated by the resistance of the air. It will go half an hour, and make, one minute with another, 20 turns in a minute, which is 600 turns in the whole. The bullet of the upper surface gives in each turn 12 sparks to the thimbles, which makes 7200 sparks; and the bullet of the under surface receives as many from the thimbles, those bullets moving in the same time 2500 feet. The thimbles are well fixed, and in so exact a circle, that the bullets may pass within a very small distance of them.

If, instead of two bullets, you put eight, four communicating with the upper surface, and four with the under surface, placed alternately (which eight, at about

six inches distance, complete the circumference) the force and celerity will be greatly increased; the wheel making 50 turns in a minute: but then it will not continue so long in motion.

The Magician's Chace.

On the top of a finely painted wire, rising perpendicularly from the conductor, let another wire, sharpened at each end, be made to move freely, as on a center. If it be well balanced, and the points be bent horizontally, in opposite directions, it will, when electrified, turn very swiftly round, by the re-action of the air against the current which flows from off the points. These points may be nearly concealed, and the figures of men and horses, with hounds and a hare or fox, may be placed upon the wires so as to turn round with them, when they will look as if the one pursued the other. If the number of wires proceeding from the same center be increased, and a still greater variety of wires proceeding from the same center be increased, and a still greater variety of figures be put upon them, the chace must be more diversified and entertaining. If the wire which supports the figures have another wire finely pointed, rising from its center, a second set of mires, furnished with another sort of figures, may be made to revolve above the former, and either in the same or the contrary direction, as the operator shall think, fit.

If such a wire, pointed at each end, and the ends bent in opposite directions, be furnished like a dipping needle, with a small axis fixed in its middle, at right angles with the bending of the points, and the same be placed between two insulated wire strings, near and parallel to each other, so that it may turn on its axis, freely upon and between them, it will, when electrified, have a progressive as well as circular motion, from one end of the wires that support it to the other; and this even up a considerable ascent.'

The Planetarium.

From the branch suspend six concentric hoops of metal, at different distances from each other; and under them, on a stand, place a metal plate, at the distance of about half an inch. Then place upon the plate, within each hoop, and near to it, a round glass bubble, blown very light. These bubbles, and the distances between the hoops should correspond to the different diameters of the planets, and those of their orbits; but as that cannot be, on account of the vast disproportion between them, it must suffice here to make a difference that bears some relation to them.

Now, the hoops being electrified, the bubbles placed upon the plate, near the hoops, will be immediately attracted by them; in consequence of which, that part of a bubble which touches a hoop will acquire some electric virtue, and be repelled. The electricity not being diffused over the whole surface of the glass, another part of the surface will be attracted, while the former goes to discharge its electricity upon the plate. This will produce a revolution of the bubble quite round the hoop, as long as the electrification is continued, and will be either way, just as the bubble happens to set out, or is driven by the operator. A ball hung over the center of all the hoops will serve to represent the sun in the center of its system. If the room be darkened the several glass balls will appear beautifully illuminated. This experiment affords a remarkable instance of electric attraction and repulsion.

The Incendiaries.

Let a person stand upon a stool made of baked wood, or upon a cake of wax, and hold a chain communicating with the branch. Upon turning the wheel, he will soon be electrified; his whole body, in reality, making a part of the prime conductor, and will exhibit the same appearances; emitting sparks wherever he is touched by any person standing on the floor. If the prime conductor be very large, the sparks may be rather