Weight |Length of the |Interior diameter|Height of the of rockets.|moulds without| of the moulds. | nipples. | their feet. | | -----------+--------------+-----------------+------------- 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.