Under the same head fall the Light group, which are wide and comparatively thin cases filled with coloured or “bright” (as white composition is known in the trade) composition. They are used either for illuminating as Bengal lights, or for signalling purposes; if for the latter, they are generally provided with a wooden handle and some means of self-ignition.
The name Bengal light is probably based on the use of Bengal saltpetre, and does not indicate their origin in that province.
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 paper round in the form of a tube, the space so formed containing some mealed powder.
He also describes what he calls fixed wheels, which are in effect the fixed sun of to-day; that is, a framework with cases arranged radially so that the fire is thrown out from the centre.
As variations of the above, he suggests various effects such as “a fixed wheel which shall give divers reports,” “which shall cast forth divers fisgigs, and likewise as many reports or breakers,” “which shall cast forth many rockets into the ayre.” The latter is evidently the prototype of a piece known later as the rocket wheel, popular for some time, but little used at the present, the objection to it being that there is no control over the direction in which the rockets fly from it. The wheel revolves horizontally, and projects a series of rockets into the air as it revolves.