Читать книгу The Pyrotechnist's Treasury; Or, Complete Art of Making Fireworks - Thomas Kentish - Страница 20

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Put into a gallipot, or basin, some hot starch, made as before directed, or some cold gum-water, or cold dextrine solution; and with a small stencil-brush, or a ³⁄₈ sash-tool, cut across the middle to make the bristles short and stubby, stir in some meal-powder, till it is well mixed and looks like black paint. To avoid repetition, it will be convenient to refer to this under the name of Meal-paste. Take two towel-horses, fig. 14, and set them parallel 5, 10, or 20 feet apart. In the top rail of each, drive four nails ¹⁄₂ an inch asunder. Fix the dry cotton to the nail a, carry it across to the opposite nail b, pass it round the second nail c, bring it to the opposite second nail, and so on, till the cotton lies in four parallel lines, like the strings of a harp placed horizontally. Hitch the cotton, without cutting it, to the hook of the weight, fig. 15. This weight is made by taking a piece of brass tube, 1 inch diameter, and 4 inches long. Stop one end with a bung, fill it with melted lead; and before it sets push in a lucifer match, having previously cut off the priming. As soon as the lead is cold, pull out the match, which having been partially burnt smaller, will come out easily, and in the hole left by it screw a cup-hook, as drawn. Invert the weight, pick out the bung, and fill its place with more melted lead. Now procure two pieces of planed deal board; one 4 inches square, the other 6 inches square. With the left hand hold the smaller piece close underneath the cotton; and with the sash-tool or stencil-brush, work the meal-paste well into the fibres of the threads, pressing the cotton on the board till it is thoroughly soaked, and rolling it over, laterally, to make it as round and smooth as possible. It is best to begin on the left, and work towards the right. If the wetting slackens the threads, pull them tight. Now brush some meal-powder through a fine sieve, to free it from lumps; put a tablespoonful or two upon the larger board; hold it close under the four threads, as the other, with the left hand, and move it laterally forwards and backwards, and down the whole length, at the same time brushing the meal over the threads, with a soft, dry, sash-tool, till they are smothered, and giving them an occasional jar to shake off the superfluous meal. By a little practice they may be made as smooth and as round as a piece of wire. Leave the weight hanging to them till they are dry. Instead of four nails on each rail, a dozen may be put; and if the towel-horses are set 12 yards apart, 144 yards may be soon made. In this case, three or four heavier weights would be required. These contrivances, however, are by no means necessary for an amateur; four hooks or nails opposite four others, anyhow supported, will be sufficient; and six or eight feet apart is a good distance. A small quantity may thus be made one day, and a small quantity another; and for this purpose it is best to use gum-water, as it is always ready, and a little can be added to the dry left the day before, and a little fresh meal stirred in. Three or four threads of white darning-cotton, which is of two twists, make very good match; knitting or crochet cotton, which is of three twists, produces, alone, excellent match; two or three pieces of the first, or two of the latter, put into a leader pipe, side by side, blow through with a violent report. Match may also be made of the very narrowest white tape, ³⁄₁₆ of an inch broad; this, from its flatness, is peculiarly suited for enveloped stars. For general purposes, however, lamp cotton is decidedly the best, as it is most loosely twisted, and therefore the most absorbent. If match is liable to be exposed to damp, it should be cased in thick leaders, and be prepared with starch; in other respects, nothing can surpass gum-water. Of course iron pound-weights, with a ring in them, will answer the purpose, or an iron pestle tied to the cotton, or anything heavy; but the kind I have advised are most convenient. They will weigh about a pound and a quarter each. The weight may hang over a chair-back.

Match, to be perfect, ought, when cut across, to look black throughout; it should, also, be stiff, straight, and round; but, to test it, cut off about 10 inches; put one end of this into a leader pipe, so that 5 inches will be in the pipe, and 5 out. Hold the end of the leader with a pair of tongs, or lay it on the ground; light the naked end. If the match is good it will burn gradually, though swiftly, till it gets to the pipe; it will then blow through with a bang. The nearer the leader pipe fits the match the better, only it ought to be large enough to allow it to go easily in, without force: if laid in a roman candle case it would hardly puff: the smaller and smaller the tube becomes the louder and louder the report: the increase of power being in the inverse ratio of the diminution of space. A train of gunpowder laid in the open air, or confined in a tube, comports itself in the same way, as is well known. Match, when dry, should be kept straight; for, if it gets broken, it acts like a cracker, snapping at every break.

A piece of zinc rainwater pipe, of suitable length, furnished with a bottom and lid, or a couple of bungs, is convenient for keeping it in; but a far better contrivance is a deal box, 5 feet long, 3 inches deep, and 3 broad, made of ¹⁄₂-inch pine. The lid of this box can be readily furnished with three or five hinges, like a piano, only made with string instead of brass. Take two pieces of string, fig. 57, and tie them in a knot near the end, as at k. At x, fig. 58, make a bradawl hole through the back of the box, near the top, and push the strings through it; make another hole through the lid, put the string through it, and tie in a knot on the top, as at z: and so with the other four. This will render the explanation easier to understand; but, practically, a single piece of thicker string is best, if you can manage to tie the second knot in the exact spot you wish. The knots must not be too close to each other, as the lid requires a little play. For safety, the box ought to be furnished with a lock.