These are a large kind of serpent, charged on a nipple, like a wheel case, with solid drift and mallet. They may be 5/8 or 6/8 or larger; about 31/2 inches long. Drive in brilliant fire, or gerbe, fig. 84, 11/2 inch; fill up to within 1/2 an inch of the top with F grain powder; and plug the end with plaster of paris, or a bit of wood, fastened with a tack or two. Press a piece of touch-paper, or double-crown, into the shape of a deep pill-box; fill it with F grain powder; fit it to the mouth of the saucisson; tie round the choke; brush, with meal paste, the outside, at bottom, and dip into dry meal. These saucissons are to be fired in a volley. Procure, say 2 dozen, iron tubes, a, b, c, &c., each a foot long; fit them with a wooden bottom, fig. 92, having a tenon, t, an inch long; let it be fastened with a screw on each side. Bore a hole through, to make a communication with the mortar formed by the tube. Take a board, an inch thick, of suitable length and breadth; bore in it 2 dozen holes, of a size to fit the tenons; glue these in, so that the tubes, or mortars, stand upright, in rows, side by side, like the pieces on a chess-board. Invert it. Nail a rim all round, so as to make a box, 2 or 3 inches deep. Cut a groove from hole to hole of the tenons; connect all the holes with naked match, also push a bit of match up all the holes in the tenons; now fill the box with sawdust, and nail a board on, to serve for a bottom, and to keep the sawdust in. Invert it; and put a saucisson, mouth downwards, into each mortar. Fig. 84 represents a single saucisson; w, w, w, fig. 85, saucissons in the mortars. On firing the match at s, it is evident the cases will be driven out rapidly, one after the other. The sawdust prevents the flash igniting the whole at once.
