Thomas Kentish

“ This composition is somewhat fiercer than would suit for the regular fuse, so catches the blowing-powder sooner.
A roman candle is well charged when the stars isochronise, or come out at equal intervals of time: they should, also, theoretically, ascend to equal heights; but, with coloured stars, this cannot be perfectly insured, as some shrink more than others in drying, and, of course, fit more loosely; some are heavier, some fiercer than others.
The interval fuse must always be driven in at twice, never at once. Each star, with its blowing-powder and fuse, occupies about an inch and a half ”

“ In forming a rocket spindle, taper it no more than will just make it deliver: the thicker it is left at the top, the stronger of course it will be. For small rockets, 3⁄8 or 4⁄8, a brass, iron, or steel wire, with a few notches filed in it, or made jagged with a cold chisel and hammer, driven into a block, will hold [Pg 180] firm without a screw. I have seen them driven into a piece of thick plank, and the nipple formed with an inch-length of wood, cut cylindrical, bored and slipped over the spindle, like c in fig. 155. Indeed, a spindle might be formed from a 5-inch or 6-inch carriage-bolt. ”

“ Weights for quickmatch may be made by nearly filling the brass tube with useless rusty old nails, tacks, screws, or odd bits of iron, or brass; then pouring in melted lead. If the ladle will not hold enough lead to fill it at once, it may be poured in at twice, thrice, four or more times. A tube 11⁄4 inch diameter and 6 inches long will weigh 21⁄2 lb. This will keep a great length of match tight and straight. Half-an-inch at each end of the tube should be solid lead, one to receive the screw, and one to make a firm bottom. ”

“ Rockets are charged in choked cases, on a spindle, to leave a hollow up the middle, through which the fire may be communicated to nearly the whole of the composition at once: this causes the sudden generation of an enormous quantity of elastic vapour, which, being unable to escape instantly through the contracted aperture left for its exit, exerts its pressure in the contrary direction, and hurries the rocket forward. ”

“ There is very great difficulty, at first, in rolling so long a pipe as 17 inches; it is advisable to begin with the halfpenny pipes, which are much shorter; the same wire-former will serve for both. If you cannot succeed, get a person to help you; sixteen fingers can manage the matter easily; but it is best to master the difficulty yourself. Have a funnel as nearly the size and shape of fig. 66 as possible. It is best with a lid soldered on the top, with a circular hole in the middle, about the size of a shilling, to prevent the composition from getting spilt. ”

“ If the plaster sticks to the end of the rammer, it shows, either that you have used the plaster too wet, or have not turned the rammer round a sufficient number of times.
No more plaster must be mixed at a time than will suffice for one case. When plaster has once set, it cannot be mixed up a second time; therefore take a fresh piece of paper, and let the knife be cleaned every time. It is advisable to have two dessert-knives, then one can be used with which to scrape the other. As much plaster should be used as will fill the case up about 1⁄2 an inch. ”

“ The best way, with fresh materials, is to weigh out as much nitre, charcoal, and sulphur, as will make one small rocket. Have the nitre as fine as possible, and dry it over the fire in a 6-inch frying pan, which should be kept for the purpose. If the rocket ascends well you will know that the articles are pure, and you can proceed to use them; but if the rocket does not rise, you may conclude the articles are adulterated, the nitre with salt, or that the charcoal is perhaps merely deal sawdust, burnt in a retort. In this case you must buy the nitre in crystals, and the charcoal in sticks. ”

“ If the cracker is intended to be put into a jack-in-the-box, shell, or rocket head, push a bradawl up the mouth, [Pg 102] insert a bit of quickmatch, to project a quarter of an inch, and secure it with a little wetted meal, pressed in with a knife. The way of bending it is shown at fig. 69. It is not necessary that a cracker should contain very much powder; the loudness of the bang depends more upon the thickness of the paper than upon the quantity of the powder. So with maroons; more string and less powder, are better than more powder and less string. A very good paper for crackers is 30-lb. ”

“ 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 [Pg 31] 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. ”

“ This leader is tied, in one or more places, to one of the spokes of the wheel, and to the nave; and is left protruding at b. A tin box, or a bit of a mine case, d e f g, is attached to the fixed, or second movable piece in such a manner, as to surround, but stand clear of, the end of the match, b, as it revolves, with the wheel. A hole is made at c, and the end of a leader, from the second piece, brought through it. The inside surface of the box, d e f g, is smeared with meal-paste. When the leader catches at a, it blows through to b ”

“ When dry, brush off the green powder which will be found on the outside, with a toothbrush, into a basin of water. After a quantity is obtained, wash it as directed for sulphur, and dry it in the bag, fig. 33. Test it with litmus paper to ascertain if free from acid.
Saw a piece of coke or charcoal in two, and on the flat surface place a few copper filings; direct upon them the flame of a lamp or candle with the blow-pipe; they will simply become red-hot. Lay a few more filings, and on them a little calomel or sal-ammoniac: now direct the flame, and a beautiful blue colour will be produced. ”

“ Push the pin through the side of the leader, down into the side of the lance; then make a triangular hole through the middle of the leader, down into the middle of the lance, turning the tool round to break the priming, and secure the leader with a gum strip. The gum strip, bent round, assumes the shape of the capital letter T. The best tool for making the holes is a steel bradawl, ground triangular and to a sharp point; another bradawl ground to a tapering point like a needle, about 3⁄4 of an inch long, may be used for making holes up the lances to receive the wires. ”

“ The object of the clay, or plaster, is to prevent the composition, which, containing much charcoal, does not bind well, from getting disturbed, and the solid part diminished, which would cause the stars to be ignited while the rocket was ascending, or [Pg 43] the fuse, perhaps, to blow through at the beginning. A piece or two of naked quickmatch is to be inserted in the hole through the clay or plaster, and a long piece is to be pushed up the core, or hollow, of the rocket, as far as it will go ”

“ Let the strings be 2 feet long: fasten them to the loop; gather them together; wind them round the colour, above the pulley; fold the parachute neatly, and bring the edges down over the strings, nearly to reach the pulley: this will keep the parachute a little open, and help it to expand. Both the tissue paper and the glazed lining should be well rubbed, to get the stiffness out of them. To ascertain how a parachute will act, the learner can take the colour case, and stop one end with plaster, fill up with sand, and stop the other end with plaster. Fire it in the day time. ”

“ 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 11⁄8 inch long: choke one end, like a wheel case; set it on a nipple,and charge it with spur fire, till full within 1⁄16 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. ”

“ Gerbes, so called from the French word for wheat-sheaf, which they resemble, are fixed choked cases: they do not show well on wheels. As they contain grains of iron, they must not be under 6⁄8; for private exhibitions a good size is 9⁄8, 9⁄8 internal diameter; 12⁄8 external; 3⁄8 the diameter of the choke; 111⁄4 inches, length of case. Charge the case on a nipple, exactly like a wheel case. It is advisable to put in, first, a little clay, to protect the choke, as the fire, being fierce, would, otherwise, enlarge it, and diminish the ascent of the sparks. ”

“ Meal, or petre, added to a fuse quickens it; sulphur slackens it. 6 meal, 1 sulphur, make a quickmatch that blows through a leader with great violence. 1 meal, 1 sulphur, will scarcely burn; pure meal only should be used for match, or grain powder with hot starch. It has already been stated that nitre in powder is sometimes adulterated with salt, and that it is impossible to make a rocket with such stuff. Powdered chlorate of potash is sometimes adulterated with nitre: with such mixture it is equally impossible to produce good colours: nitre whitens flame, and overpowers colour. ”

“ A magnet is convenient for lifting tacks, small screws, &c., from divisions in nail boxes.
If the brass tube formers get tarnished, scrape off the lacquer with a knife, sand paper them anew, and give them a fresh coat of lacquer.
Let all wheel frames and woodwork be coloured black, either with paint, or with a mixture of vegetable or lamp black and size, or thin glue, to prevent their being seen. A white thread hung upon a bush, is visible many yards off; a black one can scarcely be seen a few feet distant. ”

“ The mortar is placed in a hole, dug in the ground, a few inches left standing out; the earth is shovelled in, and driven down firm; a penthouse lid, to keep out rain, dirt, and insects, renders it complete. Amateurs require nothing of this kind. A small mortar may be a tube, open at both ends, and fitted with a wooden bottom, to which it is to be firmly screwed. Fig. 94 represents such mortar: it may be 4 diameters high; and the foot should have a conical hole turned in it to receive the cone fastened to the shell. ”

“ When dry, cut off the flange; make the edge straight: rub it on a sheet of glass paper, spread flat on a board. With a 9⁄16 inch punch, cut a hole in the middle of one hemisphere; to it, glue another hemisphere: and cover with two more layers of paper, or pieces of calico. The shell may, then, [Pg 121] when dry, be filled with any kind of stars, or rains, that can be got through the hole. Along with the stars put 1⁄16 of their weight of meal powder for a bursting charge: that is, if the stars weigh 4 ounces, as they probably will, put 4 drams of mealpowder. ”

“ Making use of the perforated zinc sieve just described, all the charcoal that goes through, fine and coarse, should be used for rockets. It need not be shaken much, but brushed through with a sash-tool. Construct a second sieve with 15 perforations to the lineal inch. Iron borings for gerbes should be sifted through this; use all that goes through. Construct, also, a third sieve with 9 perforations to the lineal inch. Nothing can equal iron and steel for making sparks; but neither will keep long from rusting, after coming in contact with nitre. ”

“ 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. ”

“ If the water does not remain hot long enough to make it boil, set it in a second basin of boiling water. As soon as it has curdled, remove it; and when cold, pour it into a vial, and cork it. Spirit must never be boiled over a fire, nor near one, as the vapour might inflame. Keep the pot, therefore, while in the hot water, at a distance from a fire, or flame of a lamp or candle.
To Make Wax Solution.
Put into a vial 1⁄2 an ounce of white wax, (bleached bees' wax) , pour upon it 5 ounces of mineral naphtha, (coal or gas tar naphtha) , keep it tightly corked.
To Make Stearine Solution. ”

“ Now put in a very little powdered clay, and mallet it with fig. 18; as much clay as will reach up 1⁄12 of an inch will be sufficient; its object is to preserve the choke from burning, and getting enlarged. One cannot be too precautious with rockets. Now put in a scoop of rocket fuse, insert drift, fig. 18, and mallet the fuse in firm, with about a dozen and a half blows, or till it offers a resistance to the hand. The blows must be light and numerous, not slow and heavy, like driving a post into the ground. ”

“ This is laid in the mixture, and when it is struck with the poker, the liquid escapes, and inflames the potash and sulphur. Sulphate of copper is a particularly dangerous salt, and must never be used, as it is almost certain to cause spontaneous combustion. Chertier, to whom pyrotechny otherwise owes so much, introduced an empirical preparation, by dissolving sulphate of copper in water, together with chlorate of potash, drying it, and wetting it with ammonia: but this, however dried, when again wetted, turns litmus paper red. Practicus has named it Chertier's copper. ”

“ To distribute the fire rapidly, over an extensive piece, it is necessary, at points, to make one leader light several, simultaneously. Suppose 10 are to be lighted at once: bring the 10 ends together and tie them; envelope them with a piece of double-crown, projecting a couple of inches; in the void put a scoop of meal; bring in the single match that is to light them, and tie as usual. Paste a piece of paper over all, to make secure.
To Preserve Steel Filings, or Cast-Iron Borings.
Put 1 lb. into a frying-pan, or iron ladle, with 3 ounces of marine glue; set it over the fire ”

“ When the articles are to be mixed, they may be put into the mortar, and stirred together with a small sash-tool. A 3⁄8 inch is a convenient size. The mixture must then be put into a sieve, and shaken in the usual way; or it may be brushed through with the [Pg 9] sash-tool. Return it to the sieve, and brush or shake through again. As it lies in a heap, level or smooth it with the blade of a table knife, or any straight-edge; if thoroughly mixed it will present a uniform colour; if it appears darker in one part than in another, it must be sifted again. ”