Читать книгу The Pyrotechnist's Treasury; Or, Complete Art of Making Fireworks - Thomas Kentish - Страница 6
To Make a 5⁄8 Roman Candle.
ОглавлениеProcure a straight piece of brass tube, 6⁄8 of an inch external diameter, and 161⁄2 inches long. Saw or file off a piece, 11⁄2 inch long, fig. 1. This is for the star former, and is drawn of the correct size.
In the other piece, of 15 inches, fix a handle, as shown, in diminutive, in fig. 7. This is for the case former. It should be filed smooth at the end.
Take another piece of brass tube 41⁄2/8 or 9⁄16 of an inch external diameter, and about 161⁄2 inches long. In this also fix a handle, or fix it into a handle, fig. 4. Invert it, and set it upright in a flower-pot, filled with sand or loose mould. Melt some lead in a ladle, and pour it slowly into the tube, leaving room for the air to escape up the side, till it is full. If the lead is poured in rapidly, the confined air, expanding, jerks the metal up, and may cause serious injury. A pound or more of lead will be required. When cold, drive the end of the lead in with a hammer, and file it smooth. This is for a rammer.
Take a piece of deal, fig. 6, about 12 inches long, 6 broad, and 3⁄4 thick; and, on the top, screw a handle, like one on a copper-lid, or black-lead brush. This is for a rolling-board. An iron door-handle would serve, and may be obtained at any ironmonger's, for about 2d. or 3d. A wooden one, however, about an inch thick, not cylindrical, but slightly flat, and rounded at the edges, is preferable, as it gives more purchase for the hand.
Cut a piece of tin, or zinc, or thin board, into the shape of fig. 8, in which the distance between the arms a and b, across the dotted line, shall be 7⁄8 of an inch. This is for a gauge, with which to measure the external diameter of the case. Write upon it, "7⁄8 space."
Procure some 60 lb., 70 lb., or 84 lb. imperial brown paper: the size of a sheet will be 29 inches by 221⁄2. Cut a sheet into 4 equal parts, each 141⁄2 by 111⁄4: paste the 4 pieces on one side, and lay them one on another, with the pasted face upwards, putting the fourth piece with the pasted side downwards, upon the pasted side of the third piece. Turn them over: take off the now top piece, and lay it flat on the near edge of a table, pasted side upwards. Take the former, fig. 7, and paste the tube all over. Lay it along the edge of the paper, bend the paper over with the fingers of both hands, and roll it tightly up, until the external diameter of the case about fits the gauge, fig. 8. If the paper should be too long, of course a piece must be cut off; if it should not be long enough, more must be added, taking care to bind in the second piece with 3 or 4 inches of the first piece; for if the whole of the first piece be rolled up before beginning the second, the latter, when dry, will probably slip off, and spoil the case. The case having been rolled up, take the handle of the former in the left hand, lay the case flat on the near side of the table, take the rolling-board, fig. 6, in the right hand, press the front part of it on the case, and drive it forwards 5 or 6 times, like a jack-plane, letting the handle of the former slip round in the left hand. This will tighten the case, and render it, when dry, as hard as a book-cover.
The former must always be pasted, before rolling a case, to prevent its sticking. It should, likewise, be wiped clean with a damp sponge, before being laid aside. Brass tubes keep clean a much longer time if lacquered. To lacquer them, clean them with very fine glass-paper; make them hot by the fire, till you can just bear them on the back of the hand; then, with a camel's-hair pencil, wash them over with thin lac solution. The cases may be either 141⁄2 or 111⁄4 inches long; but 111⁄4 is the best, for when the cases are too long, the fuse, as it approaches the bottom, is apt, if slow, to smoke; if fierce, to set the top of the case in a flame. If the learner decides upon 111⁄4 inches, the former and rammer may each be 2 or 3 inches shorter.
After the first case has been rolled up to fit the gauge, it may be unrolled, and the paper measured. Future pieces of the same quire of paper can then be cut of the right size at once, so that the case will fit the gauge without further trouble.
A large slab of slate is convenient for rolling upon; but a smoothly planed board will answer every purpose.
When a number of cases are finished, hitch a piece of flax two or three times round each of them, and hang them up to dry, in a place free from draught, that they may not warp.
Flax is sold in balls; the thick yellow, at 2d., is the best. It is named, indifferently, flax, or hemp. It is much used by shoe-makers; and is sold at the grindery, or leather shops. Two or three thicknesses of this, waxed, or drawn through the hand with a little paste, is very convenient for passing round the necks of small choked cases, tying cases on wheels, &c.
