REVOLVING SUNS.
Provide a wooden wheel of the requisite size, and bring it into perfect equilibrium around its centre, in order that the least effort may make it turn round. Attach to the circumference of it jets placed in the direction of the circumference; and affix leaders of match to communicate the fire from jet to jet, according as may be required. When fire is applied to one of the jets, the recoil will immediately cause the wheel to revolve, unless it should be too ponderous or large: therefore, when these suns are intended to be of a considerable size, that is, when they consist of twenty jets, fire must be communicated at the same time to the 1st, 6th, 11th, and 16th, from which it will proceed to the 2nd, 7th, 12th, and 17th, and so on. Four jets will thus make the wheel revolve rapidly. If two similar suns be placed one behind the other, and made to turn round in a contrary direction, they will produce a very brilliant cross fire.
For a sun 5 feet in diameter, the cases should be 8 oz., filled about 10 inches in length with composition.
Four ounce cases will be required for wheels of 14, or 16 inches; if the wheels are larger, 8 oz., 1 lb., or even 2 lb. cases will be required.
The Chinese compositions are intended for cases of nine-tenths of an inch interior diameter, but they will be found to answer for cases as low as four ounces.
TOUCH PAPER.
Dissolve saltpetre in spirits of wine, or water, more or less of the saltpetre, according as the paper is to burn fast, or slow: then dip into the solution blue paper, which, when well saturated, take out, and dry for use. The touch-paper must be cut into slips, placed once round the mouth of the firework, and the end of the paper outside the case should be twisted to a point.
WHEELS, PIN, OR CATHERINE.
The pipe or case is made on a long wire former, about three-sixteenths of an inch in diameter, into which the composition is poured through a funnel, and shaken down. The case is then rolled round a small circle of wood about one inch in diameter, and not more than half an inch thick, with a hole through the centre of it for a nail, or pin. One end of the case is to be pasted round the wood, and each half turn of it secured with sealing-wax, or a strip of paper pasted across the wheel. The end is then primed.