A Table of Dimensions for Rocket Moulds, in which the Rockets are rammed solid.
| Weight of rockets. | Length of the moulds without their feet. | Interior diameter of the moulds. | Height of the nipples. | ||||
| lb. | oz. | Inches. | Inches. | Inches. | |||
| 6 | 0 | 34· | 7 | 3· | 5 | 1· | 5 |
| 4 | 0 | 38· | 6 | 2· | 9 | 1· | 4 |
| 2 | 0 | 13· | 35 | 2· | 1 | 1· | 0 |
| 1 | 0 | 12· | 25 | 1· | 7 | 0· | 85 |
| 0 | 8 | 10· | 125 | 1· | 333 &c. | 0· | 6 |
| 0 | 4 | 7· | 75 | 1· | 125 | 0· | 5 |
| 0 | 2 | 6· | 2 | 0· | 9 | 0· | 45 |
| 0 | 1 | 4· | 9 | 0· | 7 | 0· | 35 |
| 0 | ½ | 3· | 9 | 0· | 55 | 0· | 25 |
| 6 drams | 3· | 5 | 0· | 5 | 0· | 225 | |
| 4 drams | 2· | 2 | 0· | 3 | 0· | 2 | |
The diameter of the nipple must always be equal to that of the former.
I have omitted the thickness of the moulds, it being very immaterial, provided they are substantial and strong.
I would not advise any one who makes rockets for his private amusement, to ram them solid, for it requires a very skilful hand, and an expensive apparatus for boring them, which will be shewn herereafter. Driving of rockets solid is the most expeditious method, but not so certain as ramming them over a piercer, which I have found by experience.
Of Moulds for Wheel Cases, or Serpents.
[Fig. 12.] represents a mould in which the cases are drove solid; L the nipple[3], with a point[4] at top, which, when the case is filling, serves to stop the neck, and prevent the composition from falling out, which without this point it would do; and, in consequence, the air would get into the vacancy in the charge, and at the time of firing cause the case to burst. These sort of moulds are made of any length or diameter, according as the cases are required, but the diameter of the rollers must be equal to half the bore, and the rammers made quite solid.
How to roll Rocket and other Cases.
Sky rocket cases are to be made six and a half of their exterior diameter long, and all other cases that are to be filled in moulds must be as long as the moulds, within half its interior diameter.
Rocket cases, from the smallest to four or six pound, are generally made of the strongest sort of cartridge paper, and rolled dry; but the large sort are made of pasted paste-board. As it is very difficult to roll the ends of the cases quite even, the best way will be to keep a pattern of the paper for the different sorts of cases, which pattern should be somewhat longer than the case it is designed for, and on it marked the number of sheets required, which will prevent any paper being cut to waste: having cut your papers of a proper size, and the last sheet for each case with a slope at one end, so that when the cases are rolled it may form a spiral line round the outside, and that this slope may always be the same, let the pattern be so cut for a guide: before you begin to roll, fold down one end of the first sheet, so far that the fold will go two or three times round the former; then, on the double edge, lay the former with its handle off the table, and when you have rolled on the paper, within two or three turns, lay, on that part which is loose, the next sheet, and roll it all on.