It is apparent, that a variety of figures may be put in motion, and consequently new appearances formed, by different contrivances. To represent, for instance, two fighting dragons, we must have two swivels, made square; and on each swivel, tie three rockets together, on the under side. Then having two flying dragons, made of tin, fix one of them on the top of each swivel, so as to stand upright, and in the mouth of each dragon, put a case of common fire; and another at the end of the tail. Two or three port-fires may also be put on the sides of their bodies to illuminate them Put them on the line, one at each end; but let there be a swivel in the middle of the line, to keep the figures from striking together. Before the rockets are fired, light the cases on the dragons, and, if care be taken in firing both at the same time, they will meet in the middle of the line. They will then turn, and run back with great violence. The line for these rockets, must be very long.
Sec. XI. Of Signal Sky-Rockets.
Signal rockets seldom exceed a pound in weight. Those which are employed in the land and sea service, are sometimes capped, or headed, and contain stars, serpents, &c. Two sorts of signals are used when artificial works are to be exhibited; namely, one with serpents, and the other without. Rockets which are to be bounced, must have their cases made one and a half or two diameters longer than the common proportion, and, after they are filled, a small quantity of clay is put in. Then bounce and pinch them in the usual manner, and fix on each a cap. Signal sky-rockets, without bouncers, are only sky-rockets closed and capped. These are very light, and, therefore, do not require such heavy sticks as those with loaded heads. Signal rockets, with reports, are fired in small flights; and are often, as well as those without reports, used for signals of the commencement of an exhibition of fire-works.
Signal rockets may be seen at a great distance, and observed instantly, when neither flags nor telegraphs could be observed without glasses; and may be so formed, as even to communicate particular orders or intelligence, by varying their decorations, their mode of ascension, as in the caduceus rocket, and by several other means.
[CHAPTER VIII.]
OF SUNDRY FIRE-WORKS, DENOMINATED AIR-WORKS.
Before we notice the various kinds of wheel-works, and their appendages, we purpose to consider the formation of gerbes, air-balloons, mortars, bombs, tourbillons, aigrettes, and some other works.
Sec. I. Of the Composition and Mode of forming large and small Gerbes.