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.
A single Horizontal.
8. A Single Horizontal
May be rendered more pleasing by the following arrangement of the rocket. Provide a wheel, with nave, spindle, and spokes as before; and for the fells a broad cooper’s hoop of proper dimensions, nailed on to the end of the spokes, will answer very well. The wheel being thus prepared, the cases must be attached firmly to it, by means of strong pack-thread, loops passing through the circumference; and in such manner that their heads and tails, as they succeed each other, may alternately incline upwards and downwards, and likewise when fixed, come very near together.
This being done you must, from the tail of one case to the mouth of the next following, carry a leader, and well secure it by pasting paper round both the joinings:—within this pasted paper should be put a little mealed-powder, which will serve to blow off the paper, and leave no obstruction to the fire from the cases. To the spindle on which the wheel revolves, fix a case of the same kind as those on the wheel; which must be fired by a leader from the mouth of the last case on the wheel, which case should play downwards. The wheel will be much improved, if instead of a common case in the middle, you fix a case of Chinese-fire, in length sufficient to burn as long as three cases on the wheel. In all the cases, (except the first one,) on each wheel should be driven a ladle-full or two of slow-fire, in any part of the case: in the end of one or two alternate cases you may also ram a ladle-full of dead-fire composition, which must be very lightly rammed; many other changes in the appearance may be produced by alternately ramming in composition of different orders.
Horizontal Wheels are frequently fired two or three at a time; and being prepared after the same manner, will keep time with each other: when thus arranged, the slow or dead-fire is omitted. These wheels may be made from ten to twenty inches diameter.
A Horizontal Wheel, with the cases fixed, is represented in [fig. 26].