The port-holes, funnels, and scuttles, not only serve to give the fire a free passage to the outside and upper parts of the ship and her rigging, but also to allow the inward air (otherwise confined) to expand itself, and push through those holes at the time of the combustibles being on fire, and prevent the blowing up of the decks, which otherwise must happen from the sudden and violent rarefaction of the air.
In the bulkhead behind on each side, is cut a small hole, large enough to receive a trough of the same size as the others, from which, to each side of the ship, lies a leading trough, one end coming through a sally port, cut through the ship's side, and the other fixing into a communicating trough, that lies along the bulk head, from one side of the ship to the other; and being laid with quick-match, at the time of firing either of the leading troughs, it communicates the fire, in an instant, to the contrary side of the ship, and both sides burn together.
Having thus described this preparatory arrangement, we shall consider, in the next place, the combustibles made use of in fitting up a fire-ship.
Fire-barrel. The fire-barrels for this purpose are cylindrical, on account of that shape answering better both for filling them with reeds, and for stowing them between the troughs. Their inside diameters are about 21 inches, and their length 33. The bottom parts are first filled with double-dipt reeds, set on end, and the remainder with fire-barrel composition, made of the following substances.
Composition for fire-barrels, for fire-ships.
| Grained Powder | 30 | lbs. |
| Pitch | 12 | —– |
| Saltpetre | 6 | —– |
| Tallow | 3 | —– |
There are 5 holes of three-quarters of an inch in diameter, and 3 inches deep, made with a drift of that size, in the top of the composition, while it is warm; one in the centre, and the other four at equal distances, round the sides of the barrel.
When the composition is cold and hard, the barrel is primed by well driving these holes, full of fuse composition, to within an inch of the top; then fixing in each hole a strand of quick-match twice doubled, and in the centre hole, two strands the whole length; all which must be well driven with meal-powder. Then lay the quick-match all within the barrel, and cover the top of it with a dipped curtain, fastened on with a hoop to slip over the head, and nailed on.
Bavins. Bavins are made of birch, heath, or other sort of brush wood, that is both tough and quickly fired. Their length is 21/2 to 3 feet. The bush ends are all laid one way, and the other ends, tied with two bands each. They are dipped, and sprinkled with sulphur, the same as reeds; with this difference, that the bush ends only are dipped, and should be a little closed together by the hand as soon as done, to keep them more compact, in order to produce a stronger fire, and to preserve the branches from breaking in shifting and handling them.