To Form a Device, Or Design.
Take a sheet of paper, and draw upon it a representation of whatever is intended, as a temple, a mosque, a ship, a horse, George and the dragon, &c.; then cross the design with lines, at regular distances, and at right angles, so as to cover it with squares, as fig. 86. It is now requisite to have a floor, of a considerable size; but not necessarily so large as the design intended to be fired, as a part can be done at a time; this floor must be divided into large squares, and the device from the small pattern, fig. 86, transferred to it, and the outlines chalked on the floor, fig. 87. After this a number of frames are to be made, of deal, or other wood, like square lattice-work, as fig. 91. A frame is then to be laid on the floor, so as to cover a portion of the design; and the French nails, or inch rivets, before mentioned, driven in, at distances of 3 inches, to receive the lances. Every frame must be numbered, and a copy kept in miniature, so that they may be correctly fitted together, to form the figure, without delay or error. 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.