| Meal powder | parts | 5 | 15 | 6 | 8 | 16 |
| Fine charcoal | ” | 1 | 4 | — | 2 | 17 |
| Coarse charcoal | ” | — | — | 6 | — | — |
| Sulphur | ” | — | — | 2 | — | 1 |
| Saltpetre | ” | — | — | 16 | 1 | 7 |
Composition for crackers with Chinese fire—
| Meal powder | parts | 9 | 6 | 16 |
| Saltpetre | ” | 6 | 8 | — |
| Sulphur | ” | 1 | 2 | 3 |
| Charcoal | ” | 11⁄2 | 11⁄2 | 2 |
| Fine iron | ” | 5 | — | 7 |
| Sand | ” | — | 5 | — |
Composition for crackers with brilliant fire—
| Meal powder | parts | 8 | 8 | 36 | 18 | 32 |
| Sulphur | ” | 1 | 11⁄2 | 1 | 1 | 3 |
| Iron filings | ” | 2 | 21⁄2 | — | — | — |
| Litharge | ” | — | — | — | 2 | — |
| Steel filings | ” | — | — | 8 | 3 | 12 |
The paper generally used for cartridge is that known as ‘elephant’ or cartridge, the latter being the more frequently employed.
Cartridge paper is employed in the preparation of crackers, which vary from 12 to 15 inches, and 31⁄2 inches diameter. One edge of the paper is folded down about 3⁄4-inch in breadth, then the double edge is turned down about 1⁄4-inch, and the single edge is bent back over the double fold so as to form a channel 1⁄4-inch wide. This is filled with meal powder, which is then to be covered by the folds on each side, when the whole is to be pressed very smooth and close, by passing it over the edge of a flat ruler. The part containing the powder is to be gradually folded into the remainder of the paper, each fold being carefully pressed down. The cracker is then doubled backwards and forwards into as many folds of about 21⁄4 inches as the paper will allow.
The whole is pressed together by means of a wooden vice, a piece of twine is passed twice round the middle across the folds, and the joinings are secured by causing the twine to
take a turn round the middle at every turn. One of the ends of the folds may be doubled short under, which will produce an extra report, but the other must project a little beyond the rest, for the priming and capping with the touch paper. When these crackers are fired they give a report at every turn of the paper.
The crackers may also be made of two single cards, rolled over each other and covered with paper coated with paste. The crackers are partially filled with the composition by means of a tin funnel. Ordinary powder is then introduced, and the remaining space is filled with a little sawdust.