Fig. 1. and Fig. 6.
Fig. 1. (cont.) and Fig. 6.—The broach or piercer I, fig. 1, (a section of which is represented in fig. 6), is a truncated cone, having a hemispherical summit. The cone is the part from a to b, fig. 6. The diameter of the base of the cone at b, ought to be two-fifths of the interior diameter of the case, and the diameter at the summit, one-fifth, which is also the diameter of the small hemisphere at the top. The height from b to a, ought to be seven times the interior diameter of the case, or 17.5 times the diameter of the base b. The part n, fig. 1, and from b to c, fig. 6, is rounded. Its diameter ought to be that of the interior of the case, and its height, seven-tenths of that diameter. This is called the nipple, and is the part, which gives shape to the cup o, fig. 10. The part m, fig. 1, and from c to d, fig. 6, is cylindrical, and may be made of any height or diameter, provided the latter is not less than that of the cone. It is generally one-twentieth more than the exterior diameter. This part ought to penetrate into the bottom of the charging mould, G, fig. 1, and fit closely, so as to be firm. The part from d to e, fig. 6, is the blade or tongue of the broach. It is rectangular, and enters into the block H, fig. 1, where it is firmly fixed. The size of this part is arbitrary, as well as that of the block H, fig. 1.
Fig. 2.—The Rocket finished.
Fig. 3.—Conical Mandril or Former, for the head of the Rocket.
Figs. 4 & 5.—Head of the Rocket and Pot de fusée.
Figs. 7 & 8.—Mealing table and Mullar.
Fig. 9.—The Rocket case choaked, and prepared for charging.
Fig. 10.—Section of the Rocket, after charging.
Fig. 11.—The Rocket with its stick. For want of room, the stick is represented in two pieces.