Fires are often made to intersect each other, which has a good effect. For this purpose a perpendicular post is provided, of any thickness, so that it is sufficiently strong to hold the cases. There are two pieces of wood which go across the post, two feet six inches apart and two feet in length. On the end of each of these pieces there is usually a five-pointed star. Six stars are mostly employed. Pegs are fixed to the post in such a way that two of them incline upwards and two downwards, both forming an angle of ninety degrees, or forty-five degrees with the post. To these pegs are fixed half pound cases of brilliant fire. All the cases and stars must be fired at once. It is obvious that by this arrangement of the cases, the fires must cross, and thus by intersecting each other afford a greater variety.
Sec. X. Of the Pyramid of Flower Pots.
This piece is formed by attaching to a post, ten or twelve feet high, and placed perpendicularly in the ground, four rails or pieces, two feet apart, which must diminish in length, so as to represent a pyramid. The bottom rail must be six feet long. On the bottom rail fix five paper mortars, each three and a half inches in diameter. Let one be opposite the post, and the other four equally distant on each side. Load these mortars with serpents, crackers, stars, &c. In the centre of each mortar fix a case of spur-fire. On the second rail fix four mortars so as to stand exactly in the middle of the intervals of those on the bottom rail. On the third rail, place three mortars, on the fourth, two; and on the top of the post, one. All the mortars must incline a little forwards, that they may easily discharge; and the spur-fire rammed exactly alike, that the mortars may all be fired at the same time. The pipes of communication being prepared, carry them from one spur-fire to the other.
Sec. XI. Of the Dodecaedron.
The piece, required in forming a twelve sided figure, is prepared in the following manner: A ball must be turned out of solid wood, fourteen inches in diameter, and its surface is to be divided into fourteen equal parts. In each division bore holes of a half inch in diameter, perpendicular to the centre, so that they may all meet in the middle. In the inside of each hole, let there be turned a female screw. To all the holes but one must be made a round spoke, five feet long, with four inches of the screw at one end to fit the holes. In the screw end of all the spokes, bore a hole five inches up, which must be bored slanting so as to come out at one side a little above the screw. From these holes cut a small groove along the spoke, within six inches of the other end, where another hole through to the other side of the spoke is made. To this end fix a spindle, on which put a small wheel of three or four sides, each side six or seven inches long; these sides must have grooves cut in them, large enough to receive a two or four-ounce case. When these wheels are clothed put them on the spindles, and at the end of each spindle attach a nut to keep the wheel from falling off.
The wheels being thus fixed, carry a pipe from the mouth of the first case on each wheel through the hole in the side of the spoke, and from thence along the groove and through the other hole, so as to hang out at the screw end about an inch. The spokes being all prepared in this manner, a post must be provided on which the piece is to be fired, having an iron screw in the top of it to fit one of the holes in the ball. On the screw attach the ball and then in the top hole of the ball put a little meal-powder, and some loose quick-match. After this, screw in all the spokes, and in one side of the ball bore a hole, in which put a leader and secure it at the end. By this leader the powder and match in the centre are fired, which will light the match at the end of the spokes all at once, and by which all the wheels will be lighted at the same time. There may be an addition to this piece by fixing a small globe on each wheel, or one on the top wheel only. Gray charge may be used for the wheel cases.
Sec. XII. Of Cascades of Fire.
Cascades of fire may be made of any size, and with cases from a half pound to a pound, or more. Half pound cases are usually the size employed. Cascades may be made either fixed, or turning. The former are an assemblage of pieces of wood, furnished with cases charged with Chinese fire, and placed one above the other. The distance may be more or less; sometimes from eight to fifteen feet. The latter, or turning cascades, are constructed about four feet in diameter. The wheel is made to turn on a pivot, and is put in motion by attaching to it, in the usual manner, cases of white fire. These play horizontally. The cases of Chinese fire, which play downwards, are fixed to the wheel, or to another wheel below this, or above it, according to fancy, and are placed with their mouths downwards. Sometimes in fact they play upwards, and for that purpose are made to incline outwards. In the centre, there is a case or two of brilliant fire.
It is obvious, that this arrangement not only gives a motion to the wheel, and to the cases of Chinese fire, but produces in effect a circular sheet, which falls like a cascade.
By having an upright piece, stuck in the ground, on which are fixed three or more horizontal wheels, or segments of a circle, made permanent, and at about three feet from each other, diminishing, however, as they go up, and also in their diameter, a frame will be formed capable of holding a great number of cases. The first segment may be four feet in diameter. The top pieces may be of any length, so as to hold the cases at a little distance from each other. All the cross pieces are to be fixed horizontally, and supported by brackets. The bottom cross piece, or segment, should be about one foot six inches broad in the middle; the second, one foot; the third, nine inches; and the top piece, four inches. The cases may be made of any length, but must be filled with a brilliant charge. Bits of wood ought to be nailed on the edges of the cross pieces, having a groove cut in each piece, and sufficiently large for a case to lie in. These bits of wood are fixed, so as to incline downwards, and that the fire from one tier of cases may play over the other. Leaders are carried from one to the other, as before mentioned. Let there be a pipe, hung from the mouth of one of these cases, covered at the end with a single paper, which is burnt to fire the cascade. Nine cases generally form the first tier; seven, the second, four, the third; and three, the last. These cases play downwards, except the three at top, one of which is vertical and the other two inclining at an angle of about forty-five degrees. The arrangement may be varied at pleasure. The only thing to be attended to is, to fix the cases in such a way, that the fire which proceeds from them may pass over the tier immediately underneath, that the effect may be general and uniform. Chinese fire may be used, as in the former instance.