Page:Pyrotechnics the history and art of firework making (1922).djvu/206

 CHAPTER V

COMPOUND FIREWORKS

Compound fireworks are those which are composed of a number of simple fireworks or units fixed to a framework or other device so that they produce a more elaborate effect than do single fireworks.

Probably the earliest form of compound firework was the wheel. After the sky rocket had become an established fact, it was a small step to tie rockets round a wheel, so that when fired they caused it to revolve.

Babington gives several devices based on the idea of imparting movement to a wheel by rockets: he describes horizontal and vertical wheels, which appear to be the same piece fired either horizontally or vertically. In neither case is there any further effect than the fire from the rockets tied to the periphery. His illustration shows no less than sixteen rockets to fire singly in succession, which would, by modern standards, make a rather lengthy and monotonous piece. He also describes ground wheels, which consist of two wheels fitted to an axle with a smaller wheel placed centrally between them The centre wheel has rocket cases fitted to it, causing the whole arrangement to revolve and run along the ground. As an alternative he suggests substituting cases secured to the axle without a central wheel, so arranged that one being burnt out the second burns in the opposite direction and reverses the direction of the wheels. The device is now quite obsolete.

One interesting point is the method of communicating fire from one case to the next; quickmatch, as used to-day, had not then been invented. His method was to fasten the cases head to tail a short distance apart by wrapping and tying