red hot; withdraw it with the tongs, and put it aside, to cool slowly. If copper wire is used, it will bend without preparation. String must not be employed, as it might burn, and let the case fall. Common pins, patent short whites, deprived of their elasticity, are useful for connecting the parts of lustres together.

FLOWER POTS.

These are choked cases, charged with spur fire the fire is somewhat slow, so the cases must be short: 4 inches long, and diameter is a good size. Rub the composition thoroughly up in the mortar; the vegetable black produces beautiful star-like sparks, totally dissimilar to any other. Put a little composition, at a time, into the case, and jolt it with the roman candle rammer.

Vegetable black, introduced into a star, causes it to tail, like linseed oil. Light such star on the hob; it will burn, and leave à residue, unaltered in shape; blow upon this continuously with the mouth, or, better still, with a pair of bellows the supply of oxygen

will cause it to boil up, in a state of fusion, when it will begin to throw out clusters of the peculiar starlike sparks, before mentioned, bright and yellow as new sovereigns.

Vegetable black is a pure lamp black; some samples of lamp black make equally good stars, but others are worthless. Greater reliance can be placed upon vegetable black. Vegetable black and lamp black must not be mixed with linseed oil, as such mixture is liable to spontaneous combustion.

Roll up a tube for pill boxes, of two thicknesses of brown paper. When dry, cut it into pieces about 1 inch long: choke one end, like a wheel case; set it on a nipple, and charge it with spur fire, till full within of an inch : fill up flush with a little plaster of paris, pressed in flat with a knife: prime the choked end, and put a number of such cases into a rocket head, or shell.

PORT FIRES AND SHELL FUSES.

These are unchoked cases, like roman candles; 6 inches long, internal, external, is a good size. They should be rammed,

as hard as possible; and, for this purpose, it is best to have a mould. Now, if a case is rolled of such a size that it will exactly fit into a brass tube, and is charged, in it, very hard, it will swell, and it will be almost impossible to get it out again; but if it be made a trifle smaller, so as to just slip through the tube; then, if a piece of writing paper be rolled, dry, round it, once or twice, so as to make it a tight fit, and the case is charged, it can be pushed out, like a pellet from a popgun, leaving the writing paper, generally, in the tube, or mould, and the case will come out without a wrinkle.

Let the composition be put in, very little at a time, and well driven with a solid rammer and mallet. Fig. 59 represents the mould; the foot b fits the tube a; the tenon c fits the case; a wire, d, goes through 2 holes in the brass tube, and a hole through the foot; a nut, e, to keep the wire from jarring out, is made of a piece of indiarubber: make a hole through it, with a bradawl, and slip it on the wire; or, a screw-eye may be passed through and held with a leaden, or wooden

nut.

TOURBILLIONS.*

A tourbillion, so called from the French word for whirlwind, is a case made to rotate and ascend at the same time, forming a spiral of fire, and ending in the shape of an umbrella.

TO MAKE A TOURBILLION.

Roll the case like a roman candle case, but gauge it to the thickness of a rocket case. Let the inner diameter be ; the outer ; the length of the case 7 inches, fig. 43. Το charge the case, have a mould, as directed for port-fires; and let the tenon rise exactly

of an inch up the case. Put in a little composition at a time, and mallet it as firmly as possible, till within exactly of an inch of the top of the case; so that there will be a vacancy of of an inch, at each end. Fill each of these ends flush with plaster of paris.

* Tourbillion, from tourbillon, like postillion, from postillon, the i being inserted to approximate the pronunciation of the French. In pavilion, from pavillon, and vermilion, from vermillon, one 1 is dropped; so in battalion, from bataillon; while medallion, from medaillon, retains the 11.

It is, better, too, if you can manage to fill the middle half-inch of the case with plaster of paris. It can be effected with care, and will hold the screw, hereafter to be described, more firmly.

Construct a wooden box, fig. 44, consisting of a bottom and two sides only, firmly screwed together. Each of the pieces of wood is to be 7 inches long, and an inch thick. The internal breadth of the box is to be exactly of an inch; and its internal depth exactly or, so that when the tourbillion is laid evenly in it, and pressed down to the bottom, half of the case will be in it, and half out of it. At a point b, fig. 44, on the top of the side, half an inch from a, make an ink mark : and, at a point d, half an inch from c, make another ink mark. Fig. 45 is the bottom of the box. At a point w, of an inch from the end; and, at a point z, the other end, make holes with a fine bradawl, truly, in a line down the middle of the wood, as between side and side. The distance w z is 6 inches; divide it into 3 equal parts, in the points x and y, two inches asunder. Procure 5 carpet

Bisect x y in the point s.

of an inch from