A System of Pyrotechny / Comprehending the theory and practice, with the application of chemistry; designed for exhibition and for war.

by James Cutbush

Vertical wheels are made from ten inches, to three feet in diameter, and the size of the cases must vary accordingly. Four-ounce cases will be sufficient for wheels of fourteen or sixteen inches in diameter, which is the proportion generally used. The best wood for wheels of all kinds, is the light and dry beech.

Horizontal wheels are more perfect, when their fells are made circular. In the middle of the top of the nave must be a pintle, turned out of the same piece as the nave, two inches long, and equal in diameter to the bore of one of the cases of the wheel. There must be a hole bored up the centre of the nave, within half an inch of the top of the pintle. Nail at the end of each spoke, of which there should be six or eight, a piece of wood with a groove, cut in it to receive the case. Fix these pieces in such a manner, that half the cases may incline upwards, and half downwards, and that, when they are tied on, their heads and tails, or extremities, may come very near together. From the tail of one case to the mouth of the other, carry a leader, which is necessary to be secured with pasted paper. Besides these pipes, a little meal-powder must be placed in the inside of the pasted paper, to blow off the pipe, that there may be no obstruction to the fire from the cases. By means of these pipes, the cases will successively take fire, burning one upwards, and the other downwards. On the pintle, fix a case of the same sort as those on the wheel. This case must be fired by a leader from the mouth of the last case on the wheel, which case must play downwards. Instead of a common case in the middle, we may put a case of Chinese fire, sufficiently long to burn a given time, or as long as two or three cases on the wheel.

Horizontal wheels are often fired two at a time, and made to keep time, like vertical wheels, only they are prepared without any slow or dead-fire. Ten or twelve inches will be sufficient for the diameter of wheels with six spokes.

With respect to spiral wheels, we may remark, that they are only double horizontal wheels, made in the following manner: The nave must be thicker than that of the single sort; and, instead of the pintle at top, a hole is usually made for the case to be fixed in. There are two sets of spokes, one set put near the top of the nave, and the other, near the bottom. At the end of each spoke, cut a groove, in which the cases are to be tied, there being no fell. The spokes should not be more than three and a half inches long from the nave, so that the wheel may not be more than eight or nine inches in diameter. The cases are placed in such a manner, that those at top play down, and those at the bottom play up; but let the third or fourth case burn horizontally. The case in the middle may begin with any of the others. Six spokes will be sufficient for each set; so that the wheel may consist of twelve cases, besides that on the top; the cases six inches each.

Plural wheels are different from the former. They are made to turn horizontally, and consist of three sets of spokes, placed six at top, six at bottom, and four in the middle, which must be a little shorter than the rest. Let the diameter of the wheel be ten inches. The cases must be tied on the ends of the spokes, in grooves, cut on purpose, or in pieces of wood, nailed on the ends of the spokes, with grooves cut in them as usual. In clothing these wheels, make the upper set of cases play obliquely downwards, the bottom set obliquely upwards, and the middle set, horizontally. In placing the leaders, we must so arrange them, as that the case may turn thus: namely, first up, then down, then horizontally, and so on with the rest. But another change may be made, by driving in the end of the eighth case two or three ladles full of slow fire, to burn till the wheel has stopt its course. Then let the other cases be fixed the contrary way, which will make the wheel run back again. For the case at top, we may put a small gerbe, and the cases on the spokes may be short, and filled with the strong brilliant charge.

For forming the illuminated spiral wheel, we must proceed thus: First have a circular horizontal wheel, made two feet in diameter, with a hole quite through the nave; then take three thin pieces of light board, three feet long each, and three-fourths of an inch broad. One end of each of these pieces, nail to the fell of the wheel, at an equal distance from one another; and the other end, nail to a block with a hole in its bottom, which must be perpendicular to that in the block of the wheel, but not so large. Plane a hoop down very thin and flat, and nail one end of it to the end of the wheel, and wind it round three sticks in a spiral line, from the wheel to the block at top. On the top of this block, fix a case of Chinese fire. On the wheel may be placed any number of cases, which must incline downwards, and burn two at a time. If the wheel should consist of ten cases, we may let the illuminations and Chinese fire begin with the second cases. The spindle for this wheel must be a little longer than the cone, and made very smooth at top, on which the upper block is to turn, and the whole weight of the wheel to rest.

For making the double spiral wheel, the block, or nave, must be as long as the height of the worms, or spiral lines; but must be very thin, and as light as possible. In this block fix several spokes, which must diminish in length from the wheel to the top, so as not to exceed the surface of a cone of the same height. To the ends of these spokes nail the worms, which must cross each other, several times. These worms clothe with the same illuminations as those on the single wheels, but the horizontal wheel may be clothed according to fancy. At the top of the worm, place a case of slow fire, or an amber light.

Balloon wheels turn horizontally. They are usually made two feet in diameter without any spokes, and very strong, with any number of sides. On the top of the wheel, range and fix in pots of three inches in diameter, and seven inches high each, as many as there are cases on the wheel. Near the bottom of each pot, make a small vent; and into each of these vents, carry a leader from the tail of each case. Some of the pots may be charged with stars and some with serpents, crackers, &c. As the wheels turn, the pots will be fired in succession, and throw into the air a great variety of fires.