Smoke balls burn from 25 to 30 minutes.

Composition.
lb.oz.lb.oz.
Corned mealed powder50Swedish pitch20
Saltpetre, pulverized10Tallow08
Sea coal18

To construct hollow Globes, or Cases for Light Balls, &c.

The canvas, or paper, may be formed in the following manner, viz.:—With radius of half the intended calibre, describe the circle A B C D (vide [Figure 20], Practical Geometry), and divide the same into four equal parts. From B with radius A B describe arc A E, from A with radius A B describe arc B E, and from E with radius E A describe arc A B. Eight pieces, as E A B, will form a ball nearly, the edges being brought close together.

CARCASSES.

Carcasses, a species of shell, are filled with composition, the flame from which is extremely powerful, and nearly unextinguishable. They are much used in bombardments of towns, setting fire to shipping, &c., and are discharged from guns, mortars, and howitzers, similarly to common shells; from which, however, they differ, in being made thicker, to enable them to withstand the intensity of fire; and in having three fuze holes instead of one.

Carcasses burn from 8 to 10 minutes.

Common shells may be made to produce effects similar to carcasses, by filling them with a proportion of Valenciennes composition, and bursting powder.

All carcasses have three holes; and, from guns and howitzers, are fired with sabots.

Carcass Composition.Valenciennes Composition.
lb.oz.lb.oz.
Saltpetre, pulverized6 4Saltpetre, pulverized6 4
Sulphur, sublimated2 8Sulphur, sublimated2 8
Rosin, pounded114Rosin, pounded1 4
Antimony, pounded010Antimony, pounded010
Tallow010Linseed oil, 6 oz. 14 drams.
Turpentine010