| Saltpetre, | 12 | parts. |
| Meal-powder, | 12 | —— |
| Sulphur, | 4 | —— |
| Antimony, | 4 | —— |
These ingredients are mixed in a mortar with the oil of petroleum, or, if this cannot be had, good spermaceti oil, and made into a thick paste, about the consistence of dough, and then rolled into balls. The pots generally hold two rows of these balls, distributing through them grained powder. They are then finished by using fire stone composition, beaten into pieces, and mixed with an equal quantity of grained powder, and covered with meal-powder to facilitate the inflammation.
The pots are covered over with parchment, as in the former case. It is doubtful, whether fire pots, prepared in this way, have any advantages over those, made in the manner first described.
As to the shape of fire-pots, some are cylindrical, and others of the common figure. Sometimes they are furnished with an iron hoop, with a hook of iron, by which they are suspended. They are used, when equipped in that way, more for sea service, as a defence against small boats. They are hung over the side of the vessel, so as to come in contact with the boats. When designed in particular for that use, they are charged with the following composition:
Composition for Fire-Pots, for sea service.
| Grained powder, | 6 | lbs. |
| Meal-powder, | 2 | — |
| Saltpetre, | 1 | — |
| Sulphur, | ½ | — |
| Charcoal, | 10 | oz. |
With this composition, grenades are used, which are put into the pot with powder, fire-stone, &c. and a match is fixed as before mentioned.
We are told, that fire-pots, prepared in this manner, are a defensive, as well as a dangerous weapon, and that a vessel in the Indian seas was actually saved by them, when attacked by pirates. It appears, that she endeavoured to escape from her pursuers, and finding it in vain, the crew thought of making, and employing fire-pots, for their defence; as the number of the pirates was greater than their own crew. The effect was, that, not expecting that kind of reception, they were obliged to abandon their enterprize.
There is an incendiary fire-pot, which differs from that used in fire-works for exhibition, by being made of copper and very stout. It is charged with pieces of fire-stone, previously rolled in a paste of meal-powder and brandy. A charge of powder is put in the pot, and quick-match is fixed, which must be sufficiently long to hang over the pot, and then the fire-stone is thrown in. When the match is inflamed, the powder takes fire, and disperses the fire-stone. The better plan is to have a communication to the powder below, as in the pots of ordnance, or mortars for throwing fire-balloons. We see no particular advantage to be derived from the use of this pot; as a carcass or fire-ball, thrown out of a mortar, will do more execution, and at a greater distance than any of these contrivances. The carcass rocket, however, may be an exception, if we believe the account we have of it. As an incendiary, the fire-stone, put in a shell with powder, is more effectual than the fire-pot, we have just described.