For a Ten-inch Ballóón of three Changes.
| oz. | dr. | |
| Meal powder | 3 | 0 |
| Corn powder | 3 | 2 |
| Powder for the mortar | 13 | 0 |
Length of the fuze composition one inch; the shell must be loaded with two ounce cases, drove with star composition a quarter of an inch, and on that one diameter of gold fire, then bounced three diameters; or with two ounce cases first filled one diameter with gold-fire, then a quarter of an inch with star composition, and on that one diameter and a quarter of brilliant fire. These cases must be well secured at top of the charge, lest they should take fire at both ends, but their necks must be larger than the common proportion.
To make Ballóón Fuzes.
Fuzes for air ballóóns are sometimes turned out of dry beech, with a cup at top, to hold the quick-match, as you see in [Plate II.] Fig. 28, but if made with pasted paper, they will do as well: the diameter of the former for fuzes for coehorn ballóóns, must be half an inch; for a royal fuze, five eighths of an inch; for an eight inch fuze, three quarters of an inch; and for a ten inch fuze, seven eighths of an inch. Having rolled your cases, pinch and tie them almost close at one end; then drive them down, and let them dry; before you begin to fill them, mark, on the out side of the case, the length of charge required, allowing for the thickness of the bottom; and when you have rammed in the composition, take two pieces of quick-match, about six inches long, and lay one end of each on the charge, and then a little meal powder, which ram down hard; the loose ends of the match double up into the top of the fuze, and cover it with a paper cap to keep it dry. When you put the shells in the mortars, uncap the fuzes, and pull out the loose ends of the match, and let them hang on the sides of the ballóóns; the use of the match is, to receive the fire from the powder in the chamber of the mortar, in order to light the fuze: the shell being put in the mortar with the fuze uppermost, and exactly in the center; sprinkle over it a little meal-powder, and it will be ready to be fired. Fuzes made of wood must be longer than those of paper, and not bored quite through, but left solid about half an inch at bottom; and when you use them, saw them off to a proper length, measuring the charge from the cup at top.
Of Tourbillons.
Having filled some cases within about one diameter and a half, drive in a ladle full of clay, then pinch their ends close, and drive them down with a mallet; when done, find the center of gravity of each case, where you nail and tie a stick which should be half an inch broad at the middle, and run a little narrower to the ends these sticks must have their ends turned upwards, so that the cases may turn horizontally on their centers: at the opposite sides of the cases at each end, bore a hole close to the clay with a gimblet, the size of the neck of a common case of the same nature; from these holes draw a line round the case, and at the under part of the case bore a hole, with the same gimblet, within half a diameter of each line towards the center; then from one hole to the other draw a right line. This line divide into three equal parts, and at X and Y, Fig. 29, [Plate III.] bore a hole, then from these holes to the other two, lead a quick-match, over which paste a thin paper. [Fig. 30], represents a tourbillon as it should lay to be fired, with a leader from one side hole A, to the other B. When you fire tourbillons, lay them on a smooth table, with their sticks downwards, and burn the leader thro’ the middle with a port fire. They should spin three or sour seconds on the table before they rise, which is about the time the composition will be burning, from the side holes to those at bottom.
To tourbillons may be fixed reports, in this manner; in the center of the case at top, make a small hole, and in the middle of the report make another; then place them together, and tie on the report, and with a single paper secure it from sire, this being done your tourbillon is compleated. By this method you may fix on tourbillons, small cones of stars, rains, &c. but be careful not to load them too much. One eighth of an inch will be enough for the thickness of the sticks, and their length equal to that of the cases.
The Manner of making Mortars, for throwing Aigrettes and loading and firing the same.
Mortars used for throwing aigrettes are generally made of paste-board, of the same thickness as ballóón mortars, and two diameters and a half long in the inside from the top of the foot; the foot must be made of elm without a chamber, but flat at top, and in the same proportion as those for ballóón mortars; these sort of mortars must also be bound round with cord as before mentioned; sometimes eight or nine of these sort of mortars, of about three or four inches diameter, are bound all together so as to appear but one; but when they are made for this purpose, the bottom of the foot must be of the same diameter as the mortars; and only half a diameter high. Your mortars being bound well together, fix them on a heavy solid block of wood: to load these mortars, first put on the inside bottom of each, a piece of paper, and on it spread one ounce and a half of meal and corn powder mixed; then tie your serpents up in parcels with quick-match, and put them in the mortar with their mouths downwards; but take care that the parcels do not sit too tight in the mortars, and that all the serpents have been well primed with powder, wetted with spirit of wine; on the top of the serpents in each mortar lay some paper or tow; then carry a leader from one mortar to the other all round, and then from all the outside mortars into that in the middle; these leaders must be put between the cases, and the sides of the mortar down to the powder at bottom: in the center of the middle mortar, fix a fire-pump or brilliant fountain, which must be open at bottom, and long enough to project out of the mouth of the mortar; then paste paper on the tops of all the mortars.