During the Revolution the Pennsylvania State Navy built, outfitted and maintained a fleet of fireships to aid in the defense of Philadelphia from British attack.  The vessels of the fleet consisted of fire rafts and fire ships as well as a small number of "fire boats" that were used to maneuver the vessels into place on the Delaware River.

The following text is taken from "A Treatise of Artillery", Third Edition, 1780 by John Muller, specifically Part VII, pages 207-214, and outlines in great detail how an 18th century fireship was to be prepared for an attack on enemy shipping.  The text has been transcribed exactly as it appears in the publication, and no effort has been made to correct spelling inconsistencies or alter in any way the presentation of the material.

Fireship, how to prepare it.

From the bulkhead at the forecastle to a bulkhead to be raised behind the main chains, on each side and across the ship at the bulkheads, is fixed close to the ship sides, a double row of troughs, two feet distance from each other, with cross troughs quite round, at about two feet and a half distance; which are mortised into the others.  The cross troughs lead to the sides of the ship, to the barrels, and to the port-holes, to give fire both to the barrels and to the chambers, to blow open the ports; and the side-troughs serve to communicate the fire all along the ship and the cross troughs.

The timbers of which the troughs are made are about five inches square; the depths of the troughs half their thickness, and they are supported by cross pieces at every two or three yards, nailed to the timbers of the ship, and to the wood-work which incloses the fore and main masts, and takes in an oblong in the middle of the deck, extending to the outside of both the masts, and in breadth is near one half of the deck; and is what makes the carpenter's room for his stores.  The decks and troughs are all well paved with melted rosin.

On each side of the ship are cut out six small port-holes, in size about 15 by 18 inches, the ports opening downwards, and are close caulked up: against each port is fixed an iron chamber, which, at the time of firing the ship, blows open the ports, and lets out the fire.  At the main and fore chains on each side is a wooden funnel fixed over a fire barrel, and comes through a scuttle in the deck up to the shrouds to give fire to them; and between them are cut two scuttles on each side of the ship, which also serve to let out the fire.  Both funnels and scuttles must be stopt with plugs, and have sail-cloth or canvas nailed close over them, to prevent any accident happening that way by fire to the combustibles below.

The port-hole, funnels, and scuttles, not only serve to give the fire a free passage to the outside and upper parts of the ship, and its rigging, but also for the inward air, otherwise confined, to expland itself, and push through those holes at the time of the combustibles being on fire, and prevent the blowing up the decks, which otherwise must of course happen from such a sudden and violent rarefaction of the air as will then be produced.

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 bulkhead, from one side of the ship to the other, and being laid with quickmatch only, at the time of firing either of the leading troughs, communicates the fire in an instant to the contrary side of the ship, and both sides burn together.  The communicating trough, which is fixed to the bulkhead, and the leading troughs, are the same size as the others.

Manner of Preparing Stores
F I R E - B A R R E L S

The form of the barrels should be cylindrical, both upon the account of that make answering better for filling them with reeds, and for stowing them on board between the troughs; their inside diameters are sufficient, if about 21 inches, and their length 33.  These bottom parts are first filled with short double dipt reeds set on end, and the remainder with fire-barrel composition well mixed and melted, and then poured over them.

There are 5 holes of 3/4 inches diameter, and 3 inches deep, make with a drift of that size in the top of the composition while it is warm; one in the center, 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 those holes full of fuze composition to within an inch of the top; then fixing in each hole a strand of quickmatch twice doubled, and in the center hole two strands the whole length; all which must be well set or drove in with mealed powder; then lay the quickmatch all within the barrel, and cover the top of it with a dipt curtain, fastened on with a hoop to flip over the head, and nailed on.

The barrels should be made very strong, not only to support the weight of the composition before firing, in removing and carrying them about, but to keep them together at the time they are burning; for if the staves are too slight and thin, and should burn too soon, so as to give way, the remaining composition would be apt to separate, and tumble upon the deck, which would destroy the designed effect of the barrel, which is to carry the fire aloft.

I R O N  C H A M B E R S

They are 10 inches long, and 3.5 inches in diameter; and breeched against a piece of wood fixed across the port holes, and let into another lving a little higher; when loaded they are filled almost full of corned powder, and have a wooden tompion well drove into their muzzles; are primed with a small piece of quickmatch thrust through their vents into the powder, with a part of it hanging out; and when the ship is fired, they blow open the ports; which either fall downwards, or are carried away, and so give vent for the fire out of the sides of the ship.

C U R T A I N S

Are made of barras about 3/4 of a yard wide, and one yard in length; when they are dipped, two men with each a fork (on a shaft of the same size, with one prong in each is made on purpose) must run each of their prongs through a corner of the curtain at the same end; then dip them into a large kettle of composition well melted; and when well dipped, and the curtain extended to its full breadth, whip it between two sticks of about 5.5 feet long, and 1.5 inches square, held close by two other men to take off the superfluous composition hanging to it; then immediately sprinkle saw dust on both sides to prevent its sticking, and the curtain is finished.

N.B. A copper fixed with a furnace is much better than a kettle that is not fixed, because it must be taken off from the fire for every dipping, to prevent the stripped off composition from falling into it, which would unavoidably give fire to the whole; and renders the use of a kettle tedious that way.

R E E D S

Are made up in small bundles of about 12 inches in circumference, cut even at both ends, and tied with two bands each; the longest sort is 4 feet, and the shortest 2.5; which are all the lengths that are used.  One part of them are single dipped, only at one end; the rest are double dipped, that is, at both ends.  In dipping, they must be put about 7 or 8 inches deep into a copper or kettle of melted composition; and when drained a little over it, to carry off the superfluous composition, sprinkle them over a tanned hide with pulverised sulphur, at some distance from the copper.

B A V I N S

Are made of birch, heath, or other sort of brushwood, that is both quickly fired and tough; in length 2.5 or 3 feet, the bush-ends all laid one way; and the other ends tied with two bands each.  They are dipped and sprinkled with sulphur the same are reeds, only that the bush-ends alone are dipped, and should be a little closed together by hand as soon as done, before they are sprinkled, to keep them more close, in order to give a stronger fire, and to keep the branches from breaking off in shifting and handling them.

D I S P O S I T I O N  of the S T O R E S on board, when laid for firing.

The fire-barrels are placed under the funnels and scuttles, one to each; and are fixed between the cross troughs leading to the sides of the ship, and lashed to them, and well cleeted to the deck.  Those at the funnels give fire to the main and fore shrouds; the rest rises over the deck through the scuttles.   The plugs must be taken out of the funnels and scuttles before the ship is fired, and the curtains covering the fire-barrels cut open and rolled back, and quickmatch spread, and the top of the barrels well salted with priming composition.  The curtains are nailed to the beams of the upper deck, hanging down over the troughs, bavins, and reeds.

The priming composition; a part of it is laid along the troughs, and the rest, after laying of the reeds and bavins, is regularly strewed over all.  The short reeds double dipped, with some of the single dipped, are laid along both the sides and cross troughs, and communicate the fire both to the barrels and chambers.  The rest of the single dipped reeds and bavins are set about the fire-barrels, and to the sides of the ship; and some flung upon the deck.

The quickmatch is laid two or three strands thick upon the reeds in the troughs, and about the fire-barrels and chambers, to communicate a general fire at once.   The reeds in the troughs with the quickmatch are lashed on, to prevent their falling out by the rolling of the ship.

The leading troughs are both laid with 4 or 5 strands of quickmatch; as if likewise the communicating trough, that, by firing either of the leading troughs, the communicating trough may carry the fire to the other side of the ship; which then runs along the troughs by the quickmatch on both sides, and give fire to the whole in an instant.

The C O M P O S I T I O N made use of for C U R T A I N S, R E E D S,
and B A V I N S, are all the same, viz.

Divide the composition into five pots; the pitch and tallow must be first thoroughly melted.  Tallow well the outside of the pot to take off the heat; and then put in the powder by small quantities, stirring it well about.

Priming C O M P O S I T I O N for one B A R R E L.

Take 20 lb. of powder, which mix will with the petre, sulphur, and rosin, work them well together, breaking it well in working; then put the rest of the powder in by degrees, and work it together: spread it in a trough, and through a hair sieve run 3 pints of oil all over it; then work it well together, and run it through a cane sieve.

N.B. In the following estimate for the quantity of stores requisite, the reeds for the barrels are not included; it will take 100 short double dipped more than these specified; but their value is included in the article of barrels.

S T O R E S for a F I R E S H I P  of 150 tons.

Quantity of C O M P O S I T I O N for preparing the
S T O R E S  of a F I R E S H I P.

Total weight of the composition 3017 equal to C. 26 : 3 : 2.

Composition allowed for the reeds for the barrels one fifth of the whole of the last article, which is equal to 160 lb. and makes the whole 3177 pounds, or C. 28 : 1 : 13.