Pots are charged in the following manner: We first make the sacs of powder. For this purpose, we have as many squares of paper as there are pots, which are made into cylinders on the same roller that formed the pots. Into each is put about an ounce of the charge-composition, hereafter mentioned, with two pieces of match, sufficiently long to come out an inch. They are then closed and tied, and the excess is cut off. One of these sacs is put into each pot, having previously pierced it with several small holes, and sprinkled it with meal powder. After this, the garnishing, furniture, or decoration is added, always observing to put the primed part downwards. A wad of paper is then put over the whole, and the mouth is closed with pasted paper.
Composition of the charge for fire pots.
| Gunpowder, in broken grains, | 16 | oz. |
| Charcoal, | 3 | — |
Fire pots are discharged in the way we have described, which is considered the best and most certain; or they may be fired by communicating the fire with a match, passing out of the mouth, and hanging over the sides. Another mode may be used, similar to that for discharging balloons or bombs, but on a scale proportionate thereto. Pots may be discharged in any direction; hence two pieces, or sets, may be fired adversely, like rockets from the regulated rocket case. Their effect depends, as we have frequently observed, on their furniture or decorations.
The strength of fire pots is also to be considered. If they are made three inches in interior diameter, it is prudent to cover them with stout canvass, or small cord, wrapped round and covered with a coat of glue, in the same manner as for tourbillons.
Fire pots are calculated to throw serpents, &c. in the air. Mortars, it will be recollected, are designed to discharge shells or balloons, which are thrown to a considerable height, by the powder placed in the conical cavity; whereas fire pots, although their contents are thrown out by blowing powder, are differently made at the bottom, and merely designed to project serpents, stars, &c. to a small distance. Being primed, they take fire as they pass out of the pot. The charge is sometimes gunpowder, and, as above, composed of gunpowder and charcoal, to lessen the power of the former. The principle, on which they are discharged, is the same. Fire pots are called pots of ordnance, because they are used for discharging sundry substances, by means of gunpowder.
[CHAPTER IX.]
OF PARTICULAR COMPOSITIONS.
Sec. I. Of Fire-Jets, or Fire-Spouts.