These fuses were made use of at the siege of Ham in 1761. The experiments which were made in 1792, with this composition, by an artificer belonging to the ordnance-board at Douay, have proved, that it answers every purpose for which it is invented.
The author of the Manual de l’Artilleur, from whose treatise these observations are taken, concludes this article by stating that the advantages to be derived from this invention are not so great as they at first appear.
He remarks that with respect to the real utility of the fuse à feu mort, if it be considered as tending martially to the defence of any besieged place, the argument cannot be very forcible, when we reflect, that to gain time constitutes one of the principal means of defence, and that the only way to obtain it is by regarding the besiegers’ operations. These ends are gained by various expedients. Among others, the common lighted fuse conduces not a little; since during the whole direction of the bomb against the works of the assailants, the attention of the workmen is diverted from their immediate labour, and as long as it continues in its range, much uneasiness is created, because its ultimate explosion and concomitant destruction are unknown.
Add to this, that independent of the confusion which is occasioned among the assailants by repeated projectiles, the bombadier by means of the lighted fuses, is enabled to correct his aim during the darkest night. The same principles must certainly hold good in attacks; and from a conviction of their solid utility in both instances, the common fuses have been hitherto adopted, although the kind in question has been known for several years.
Fusees à grenades, Fr. fuses for grenades. These fuses are made of the same quality of wood as those adopted for bombs. Their length is 2 inches 6 lines; their diameter at the head is 10 lines; 7 lines in diameter 1 inch from the head, and 2 lines in diameter to the sight or aperture. The composition of these fuses consists of 5 parts of priming gunpowder, 3 parts of sulphur, and 2 of saltpetre: or 3 parts of priming powder, 2 of saltpetre, and one of sulphur.
These fuses must be loaded with the same care and precision as are required in bomb-charges; that is, the thick end of the fuse must be placed downwards, so that it stands upright; the composition must then be introduced by means of a trundle, which the French call lanterne, made for that specific purpose; the composition must, after that, be well pressed in with an iron ramrod fitted to the bore of the fuse, and gradually forced in by gentle taps with a mallet. Great precaution must be observed during this operation, as too much violence might split the fuse. When the fuse has been half filled, a shorter ramrod must be used, with which the charge is completed. In making bomb-fuses great care must be taken to strike equal blows with the mallet until you get to the three last, when the strength of each blow must be increased.
Fusees d’obus, Fr. howitzer-fuses. These are generally made of the same composition and wood, as serve for bombs, and are loaded in a similar manner. They have the same dimensions when applied to calibres of 8 or 6 inches diameter; that is, they contain 5 inches 4 lines in length; 15 lines diameter at the small end, 3 lines diameter at the thick end; 13 lines diameter 1 inch from the head; the eye, or vent is 10 lines. These fuses do not exceed the vent of an howitzer, so much as bomb fuses do the vent of bombs. They are in fact, shorter.
Fusees volantes, Fr. sky-rockets. These fuses are made of various dimensions, and serve for signals in times of war. They are sometimes 2 inches and more in diameter. The cartridges with which they are loaded, contain in thickness the sixteenth part, or more of the diameter.
The composition which is used for fuses of this description, consists of 16 parts of saltpetre, 7¹⁄₂ of charcoal, and 4 of sulphur; or of 16 parts of saltpetre, 6 of charcoal, 4 of sulphur, and 2 of priming gunpowder. The materials must be carefully pounded and well mixed together. Hollow rods of various lengths are used to charge these fuses. They must have cavity enough to admit the stick.
Fuses are tied to long sticks, or rods made of very light wood, such as hazel tree which must have been cut some time, and be perfectly dry. They must likewise be straight, and contain from 7 to 8 feet in length; the thick end of the rod, in which 2 notches are made to fix it to the fuse, must be 7 or 8 lines in diameter, and at the small end 3 to 4 lines diameter. When the rod is rather heavy, it takes a more upright direction than when it is light; but it does not acquire so many degrees of elevation.