The interior diameter of port-fire moulds should be 10/16ths, of an inch, and the diameter of the former half an inch. The cases must be rolled wet with paste, and one end pinched or folded down. The moulds should be made of brass, and to take in 2 pieces lengthwise: when the case is in the two sides, they are held together by brass rings or hoops, which are made to fit over the outside. The bore of the mould must not be quite through, so that there will be no occasion for a foot. The French make the cases of five thicknesses of paper, and form the moulds upon rollers of 3/8ths of an inch in diameter.

Port fire, according to the full acceptation of the term Porte-feu of the French, means a porter, or carrier of fire, and implies all sorts of fusées or matches, by which fire is communicated.

In a treatise on Military Fire-works, as taught at Strasburg in 1764, an extract of which was translated and published by order of the War Department in 1800, there are some observations on port-fires, which, as the mode of making them according to these directions appears to have been adopted, may be useful to notice in this place.

"Port-fires may be made in two ways. The first is made and beaten in a mould; the other simply rolled on a ramrod, and filled lying on the table.

"To make port-fires of the first kind, the mould must be made of dry wood, such as pear-tree, nut or box wood. The height of the mould is 13.85 inches; its diameter at the bottom, 3.2 inches; its diameter above, 2.13 inches; diameter of the hole or caliber, .62 inches; height of the base, 2.13 inches; its diameter, 3.2 inches.

"The base of the mould has in the middle a nob, which the turner leaves there, the diameter of which is equal to the whole of the mould, and one inch high, including the circle, which should be rounded like a hemisphere. There must be three rods, one of which, of hard wood to roll the cartridge upon; the two others of iron to ram down with. The one to roll upon, or the form, is to be of the length of the mould, exclusive of the handle, which is 3.2 inches longer. The diameter of this rod is .45 parts of an inch. The first, or greater one to charge with, is the same length with that to roll upon; the second is but half the length, and both are .44 parts of an inch in diameter.

"To make good cartridges, you must have good paper, well sized, cut according to the length of the rolling rod or form, which must be rolled very tightly round the form, so that the vacancy left may be exactly equal to the size of the mould, and that the paper should exactly fill the space between the form and the mould. Then the form is drawn out, after having tied it at the end with packthread. To fill it, it must be replaced in the mould. A cupful of composition is then put in, and five or six strokes given with the large ramrod. The ramrod is then withdrawn, and a new charge is put in, which is beaten like the first, until the cartridge is filled to the height of the mould. It is then drawn out, and primed with priming powder.

"The port-fire is filled with ease, in using a tunnel placed at the end of the cartouch, through which you pass the rod.

"Composition of Port-fires of the first kind.

Saltpetre4 lbs. 2oz.
Sulphur112
Priming powder012