Part 27 (1/2)

SLOW FIRE FOR WHEELS.

lb. oz.

Saltpetre 0 4 Brimstone 0 2 Meal-powder 0 1-1/2

or, 1 oz. of brimstone may be used with 1 oz. of antimony.

DEAD FIRE FOR WHEELS.

oz. dr.

Saltpetre 4-1/4 0 Brimstone 0-1/4 0 Lapis-caliminaris 0 2 Antimony 0 2

_Single Vertical Wheels._--There are different sorts of vertical wheels; some having their fells of a circular form, others of an hexagonal, octagonal, or decagonal form, or of any number of sides, according to the length of the cases you design for the wheel; the spokes being fixed in the nave, nail slips of tin, with their edges turned up so as to form grooves for the cases to lie in; form the end of one spoke to that of another; then tie the cases in the grooves head to tail, in the same manner as those on the horizontal water-wheel; so that the cases, successively taking fire from one another, will keep the wheel in an equal rotation. Two of these wheels are very often fired together, one on each side of a building, and both lighted at the same time, and all the cases filled alike, to make them keep time together; as they will, if made by the following directions: In all the cases of both wheels, except the first, on each wheel drive two or three ladlesful of slow fire, in any part of the case; but be careful to ram the same quant.i.ty in each case; and in the end of one of the cases, on each wheel, you may ram one ladleful of dead-fire composition, which must be very lightly driven; you may also make many changes of fire by this method.

Let the hole in the nave of the wheel be lined with bra.s.s, and made to turn on a smooth iron spindle. On the end of this spindle let there be a nut, to screw off and on; when you have put the wheel on the spindle, screw on the nut, which will keep the wheel from flying off.

Let the mouth of the first case be a little raised. Vertical wheels are made from ten inches to three feet diameter, and the size of the cases must differ accordingly; four-ounce cases will do for wheels of 14 or 16 inches diameter, which is the proportion generally used. The best wood for wheels of all sorts is a light and dry beech.

_Horizontal Wheels._--They are best 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. The wheel being made; 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 may come very nearly together: from the tail of one case to the mouth of the other carry a leader, which should be secured with pasted paper. Besides these pipes, it will be necessary to put a little meal-powder within 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, you may put a case of Chinese fire, long enough to burn as long as two or three of the cases on the wheel.

Horizontal wheels are often fired two at a time, and made to keep time like vertical wheels, only they are made without any slow or dead fire; 10 or 12 inches will be enough for the diameter of wheels with six spokes.

_Spiral Wheels._--They are only double horizontal wheels, and made thus: the nave must be about six inches long, and rather thicker than the single sort; instead of the pintle at top, make a hole for the case to be fixed in, and two sets of spokes, one set near the top of the nave, and the other near the bottom. At the end of each spoke cut a groove wherein you tie the cases, there being no fell: the spokes should not be more than two inches and a half long from the naves, so that the wheel may not be more than eight or nine inches diameter; the cases are placed in such a manner, that those at top play down, and those at bottom play up; but let the third or fourth case play horizontally. The case in the middle may begin with any of the others; six spokes will be enough for each set, so that the wheel may consist of 12 cases, besides that on the top: the cases six inches each.

_Plural Wheels._--Plural wheels are made to turn horizontally, and to consist of three sets of spokes, placed six at top, six at bottom, and four in the middle; which last must be a little shorter than the rest: let the diameter of the wheel be 10 inches: the cases must be tied on the ends of the spokes in grooves cut on purpose, or on 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, they must be managed so that the cases may burn thus, viz., first up, then down, then horizontal, and so on with the rest. But another change may be made, by driving in the end of the eighth case two or three ladlesful of slow fire, to burn till the wheel has stopped 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 you may put a small gerbe; and let the cases on the spokes be short, and filled with a strong brilliant charge.

_Illuminated Spiral Wheel._--First have a circular horizontal wheel made two feet diameter, with a hole quite through the nave; then take three thin pieces of deal, three feet long each, and three-fourths of an inch broad each: nail one end of each of these pieces 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. The wheel being thus made, have a loop planed down very thin and flat; then nail one end of it into the fell of the wheel, and wind it round the 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 you may place any number of cases, which must incline downwards, and burn two at a time. If the wheel should consist of ten cases, you 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.

_Double Spiral Wheels._--For these wheels, the block or nave must be as long as the height of the worms, or spiral lines, but must be made very thin, and as light as possible. In this block must be fixed 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: close these worms with illuminations, the same as those on the single wheels; but the horizontal wheel you may clothe as you like. At the top of the worm place a case of spur-fire, or an amber light.

_Balloon Wheels._--They are made to turn horizontally: they must be made two feet diameter, without any spokes, and very strong, with any number of sides. On the top of a wheel range and fix in pots, three inches diameter and seven inches high each, as many of these as there are cases on the wheel: near the bottom of each pot make a small vent; into each of these vents carry a leader from the tail of each case; load some of the pots with stars, and some with serpents, crackers, &c. As the wheels turn, the pots will successively be fired, and throw into the air a great variety of fires.

BALLOON CASES.

You must have an oval former, turned of smooth wood; then paste a quant.i.ty of brown or cartridge-paper, and let it lie till the paste has soaked all through; this done, rub the former with soap or grease, to prevent the paper from sticking to it; then lay the paper on in small slips, till you have made it one-third of the thickness of the sh.e.l.l intended. Having thus done, set it to dry; and when dry, cut it round the middle, leaving about one inch not cut, which will make the halves join much better than if quite separated. When you have some ready to join, place the halves even together, and let that dry; then lay on paper all over as before, everywhere equal. When the sh.e.l.l is thoroughly dry, burn a vent at top with a square iron.

Sh.e.l.ls that are designed for stars only, may be made quite round, and the thinner they are at the opening the better; for if they are too strong, the stars are apt to break at the bursting of the sh.e.l.l.

Balloons must always be made to go easy into the mortars.

MORTARS.

These mortars must be made of pasteboard, with a small copper chamber at bottom, in which the powder is to be placed, on which the balloon is to be put. In the centre of the bottom of this chamber make a small hole a little down the foot: the hole must be met by another of the same size as the foot. Then putting a quick-match, or touch-string, of touch-paper, into the hole, your mortar will be ready to be fired.

_To load Air Balloons with Stars, Serpents, &c., &c._--When you fill your sh.e.l.ls, you must first put in the serpents, rains, &c., or whatever they are composed of, then the blowing powder; but the sh.e.l.ls must not be quite filled. All those things must be put in at the fuse-hole, but marrons being too large to go in at the fuse-hole, must be put in before the inside shall be joined. When the sh.e.l.ls are loaded, glue and drive in the fuses very tight. The number and quant.i.ties of each article for the different sh.e.l.ls are as follows:

BALLOONS ILLUMINATED.

oz.