Though the directions already given may be sufficient for these rockets, we shall here add an improvement on a very essential part of this device, which is, that of hanging the rockets to be fired; for before the following method was contrived, many attempts proved unsuccessful. Instead, therefore, of the old and common manner of hanging them on nails or hooks, make use of the following contrivance: Have a ring made of strong iron wire, large enough for the stick to go in as far as the mouths of the rockets; then have another ring supported by a small iron, at some distance from the post or stand to which it is fixed; then have another ring fit to receive and guide the small end of the stick. Rockets thus suspended will have nothing to obstruct their fire; but when they are hung on nails or hooks, in such a manner that some of their mouths or against or upon a rail, there can be no certainty of their rising in a vertical direction.
To fire Rockets without Sticks.—You must have a stand, of a block of wood, a foot diameter, and make the bottom flat, so that it may stand steady: in the centre of the top of this block draw a circle two inches and a half diameter, and divide the circumference of it into three equal parts; then take three pieces of thick iron wire, each about three feet long, and drive them into the block, one at each point made on the circle; when these wires are driven in deep enough to hold them fast and upright, so that the distance from one to the other is the same at top as at bottom, the stand is complete.
The stand being thus made, prepare the rockets thus: Take some common sky-rockets of any size, and head them as you please; then get some balls of lead, and tie to each a small wire two or two feet and a half long, and the other end of each wire tie to the neck of a rocket. These balls answer the purpose of sticks, when made of a proper weight, which is about two-thirds the weight of the rocket; but when they are of a proper size, they will balance the rocket in the same manner as a stick, at the usual point of poise. To fire these, hand them one at a time, between the tops of the wires, letting their heads rest on the point of the wires, and the balls hang down between them: if the wires should be too wide for the rockets, press them together till they fit; and if too close, force them open; the wires for this purpose must be softened, so as not to have any spring, or they will not keep their position when pressed close or opened.
Scrolls for Rockets.—Cases for scrolls should be made four or five inches in length, and their interior diameters three-eighths of an inch: one end of these cases must be pinched quite close before beginning to fill; and when filled, close the other end; then in the opposite sides make a small hole at each end, to the composition, as in tourbillons, and prime them with wet meal-powder. You may put in the head of the rocket as many of these cases as it will contain: being fired, they turn very quick in the air, and form a scroll or spiral line. They are generally filled with a strong charge, as that of serpents or brilliant fire.
Stands for Rockets.—Care must be taken, in placing the rockets, when they are to be fired, to give them a vertical direction at their first setting out; which may be managed thus: Have two rails of wood, of any length, supported at each end by a perpendicular leg, so that the rails may be horizontal, and let the distance from one to the other be almost equal to the length of the sticks of the rockets intended to be fired; then in the front of the top rail drive square hooks at eight inches distance, with their points turned sidewise, so that when the rockets are hung on them, the points will be before the sticks, and keep them from falling or being blown off by the wind; in the front of the rail at bottom must be staples, driven perpendicularly under the hooks at top; through these staples put the small ends of the rocket-sticks. Rockets are fired by applying a lighted port-fire to their mouths.
Table-Rockets.—Table-rockets are designed merely to show the truth of driving, and the judgment of a fire-worker; they having no other effect, when fired, than spinning round in the same place where they began, till they are burnt out, and showing nothing more than a horizontal circle of fire.
The method of making these rockets is thus:—Have a cone turned out of hard wood two inches and a half in diameter, and as much high; round the base of it drive a line; on this line fix four spokes, each two inches long, so as to stand one opposite the other; then fill four nine-inch one-pound cases with any strong composition, within two inches of the top: these cases are made like tourbillons, and must be rammed with the greatest exactness.
The rockets being filled, fix their open ends on the short spokes; then in the side of each case bore a hole near the clay; all these holes, or vents, must be so made that the fire of each case may act the same way; from these vents carry leaders to the top of the cone, and tie them together. When the rockets are to be fired, set them on a smooth table, and light the leaders in the middle, and all the cases will fire together and spin on the point of the cone.
These rockets may be made to rise like tourbillons, by making the cases shorter, and boring four holes in the under side of each at equal distances; this being done they are called double tourbillons.
Note.—All the vents in the under side of the cases must be lighted at once, and the sharp point of the cone cut off; at which place make it spherical.