Wheels.
7. Wheels.
A great variety of forms may be given to this kind of fire-works. They are so called because they are generally made in the shape of wheels, with a nave and spokes radiating from the centre; on the extremities of the latter are adjusted charged cases, of the rocket kind, without heads; in such manner that the tail of one is connected with the head of another, by which method they will take fire successively, and keep up a continued revolution of the apparatus to which they are fixed.
These wheels are either vertical or horizontal, single or double. A single vertical or horizontal, may be made after the manner described in Art. 6, Rockets.