Caduceus rockets in rising form two spiral lines, or double worm, by reason of their being placed obliquely, one opposite the other; and their counterpoise in their center, which causes them to rise in a vertical direction. Rockets for this purpose, must have their ends choaked close, without either head or bounce; for a weight at top, would be a great obstruction to their mounting; though I have known them sometimes to be bounced, but then they did not rise so high as those that were not, nor do any Caduceous rockets ascend so high as single ones; because of their serpentine motion, and likewise the resistance of air, which is much greater than two rockets of the same size would meet with, if fired singly.
By [Fig. 33]. you see the method of fixing these rockets: the sticks for this purpose, must have all their sides equal, which sides should be equal to the breadth of a stick, proper for a sky rocket of the same weight as those you intend to use, and to taper downwards as usual, long enough to ballance them, one length of a rocket, from the cross stick; which must be placed from the large stick, six diameters of one of the rockets, and its length seven diameters so that each rocket when tied on, may form with the large stick an angle of sixty degrees. In tying on the rockets, place their heads on the opposite sides of the cross stick; and their ends on the opposite sides of the long stick, then carry a leader from the mouth of one, into that of the other. When these rockets are to be fired, suspend them between two hooks or nails, then burn the leader through the middle, and both will take fire at the same time. Rockets of one pound, are a good size, for this use.
Of Honorary Rockets.
Honorary rockets are the same as sky rockets, except that they carry no head nor report, but are closed at top, on which is fixed a cone, then on the case, close to the top of the stick, you tie a two ounce case, about five or six inches long, filled with a strong charge, and pinched close at both ends; then in the reverse sides at each end, bore a hole, in the same manner as in Tourbillons; from each hole, carry a leader, into the top of the rocket. When the rocket is fired, and arrived to its proper height, it will give fire to the case at top, which will cause both rocket and stick, to spin very fast, in their return, and represent a worm of fire, descending to the ground.
There is another method of placing the small case, which is by letting the stick rise a little above the top of the rocket, and tying the case to it, so as to rest on the rocket: these sort of rockets have no cones.
There is also a third method, by which these kind of rockets are managed, which is thus: In the top of the rocket fix a piece of wood, in which drive a small iron spindle, then make a hole in the middle of the small case, through which put the spindle; then fix on the top of it a nut, to keep the case from falling off; when this is done, the case will turn very fast, without the rocket: but this method does not answer so well, as either of the former.
[Fsg. 34.] is a honorary rocket compleat. The best sized rockets for this purpose are those of one pound.
To divide the Tail of a Sky Rocket, so as to form an Arch when ascending.
Having some rockets made, and headed according to fancy, and tied on their sticks; get some sheet tin, and cut it into round pieces, about three or four inches diameter, then on the stick of each rocket, under the mouth of the case, fix one of these pieces of tin; sixteen inches from the rockets neck, and support it by a wooden bracket, as strong as possible: the use of this, is, that when the rocket is ascending, the fire will play with great force on the tin, which will divide the tail in such a manner, that it will form an arch, as it mounts, (and will have a very good effect if well managed) if there be a short piece of port-fire, of a strong charge, tied to the end of the stick, it will make a great addition; but this must be lighted, before you fire the rocket.
To make several Sky Rockets, rise together, in the same direction, and equally distant from each other.