Fuses

in artillery, are chiefly made of very dry beach wood, and sometimes of horn-beam taken near the root. They are turned rough and bored at first, and then kept for several years in a dry place. The diameter of the hole is about ¹⁄₄th of an inch; the hole does not go quite through, having about ¹⁄₄ of an inch at the bottom; and the head is made hollow in the form of a bowl. The composition for fuses is, salt petre 3, sulphur 1, and mealed powder 3, 4, and sometimes 5. This composition is driven in with an iron driver, whose ends are capped with copper, to prevent the composition from taking fire; and to keep it equally hard; the last shovel-full being all mealed powder, and 2 strands of quick match laid acro each other, being driven in with it, the ends of which are folded up into the hollow top, and a cap of parchment tied over it until it be used. When these fuses are driven into the loaded shell, the lower end is cut off in a slope, so that the composition may inflame the powder in the shell. The fuze must be of such a length as to continue burning all the time the shell is in its range, and to set fire to the powder as soon as it touches the ground, which occasions the shell instantly to burst into many pieces. When the distance of the battery from the object is known, the time of the shell’s flight may be computed to a second or two; which being ascertained, the fuse may be cut accordingly, by burning two or three, and making use of a watch, or of a string by way of a pendulum, to vibrate seconds.