Plate. 8
There is another method of making these wheels, called the French method; which is, by winding on the pipes without paste, and sticking them together with sealing wax, at every half turn; so that when they are fired, the end will fall loose every time the fire passes the wax, by which means the circle of fire will be considerably increased. The formers for these pipes are made from one and a half to four sixteenths of an inch diameter, and the composition for them as follows; meal powder eight ounces, salt petre two ounces, and sulphur one; among these ingredients, may be mixed a little steel-filings, or the dust of cast-iron; this composition should be very dry, and not made too fine, or it will stick in the funnel. These wheels may be fired on a large pin, and held in the hand with safety.
Of Fire Globes.
There are two sorts of fire globes, one with projected cases, and the other with the cases concealed in the following manner; have a globe made of wood, of any diameter you chuse, and divide the surface of it into fourteen equal parts, and at each division bore a hole perpendicular to the center; these holes must be in proportion to the cases intended to be used; in every hole, except one, put a case filled with brilliant, or any other charge, and let the mouths of the cases be even with the surface of the globe; then cut in the globe a groove, from the mouth of one case to the other, for leaders, which must be carried from case to case, so that they may all be fired together; this being done, cover the globe with a single paper, and paint it. These sort of globes may be used to ornament a building.
Fire-globes with projected cases are made thus; your globe being made with fourteen holes bored in it as usual, six in every hole, except one, a case, and let each case project from the globe two thirds of its length; then cloath all the cases with leaders, so that they may all take fire at the same time. Fire-globes are supported by a pintle, made to fit the hole in which there is no case.
To thread and join Leaders, with the method of placing them on different Works.
Joining and placing of Leaders is a very essential part of fireworks, as it is on the leaders, that the performance of all complex works depend; for which reason I shall endeavour here to explain the method of conducting pipes of communication, in as plain a manner as possible. Your works being ready to be cloathed, proceed thus; cut your pipes of a sufficient length to reach from one case to the other, then put in the quick match, which must always be made to go in very easy; when the match is in, cut it off within about an inch of the end of the pipe, and let it project as much at the other end; then fasten the pipe to the mouth of each case with a pin, and put the loose ends of the match into the mouths of the cases, with a little meal powder; this being done to all the cases, paste over the mouth of each two or three bits of paper; the preceding method is used for large cases, and the following for small cases and illuminations; first thread a long pipe, then lay it on the tops of the cases, and cut a bit off the under side, exactly over the mouth of each case, so that the match may appear; then pin the pipe to every other case, but before you put on the pipes, put a little meal powder in the mouth of each case; if the cases thus cloathed be port-fires on illuminated works, cover the mouth of each case with a single paper; but if they are choaked cases, situated so that a number of sparks from other works may fall on them before they are fired, secure them with three or four papers, which must be pasted on very smooth, that there may be no creases for the sparks to lodge in, which often set fire to the works before their time; avoid, as much as possible, placing the leaders too near together, or one across the other so as to touch, as it sometimes happens that the flash of one will fire the other; therefore if your works should be so formed, that the leaders must cross or touch, be sure to make them very strong, and secure them well at the joints and at every opening.
When a great length of pipe is required, it must be made by joining several pipes together, in this manner; having put on one length of match as many pipes as it will hold, paste paper over every joint; but if a still greater length be required, more pipes must be joined, by cutting off about an inch of one side of each pipe near the end, and laying the quick match together, and tieing them fast with small twine; after which, cover the joining with pasted paper.
The manner of placing Fireworks to be exhibited, with the order of Firing.