2052. To Charge Rocket Cases

2052.    To Charge Rocket Cases. In charging rocket cases, in order to increase the rapidity of its discharge a wire is sometimes inserted through the centre of the charge, the rammer being constructed with a small bore through its length, to receive this wire when ramming the charge. This wire is withdrawn when the charge is complete, and the space it has left is filled with a quick match (see No. 2060 (To Make Quick Match)), which thus sets fire to the entire charge at once. This central space is called the soul of the rocket, and the adop tion of this arrangement is necessary for large rockets, especially those having heavy pots.

2053. To Choke Firework Cases

2053.    To Choke Firework Cases. A short cylindrical piece of wood, of the same diameter as the thin end of the rod used for rolling a case, is furnished with a wire, the thickness of which must be the same as the desired bore of the choke. The end of the rod has a hole bored in it to receive this wire loosely. A is the rod on which the case is to be rolled; C the cap of the same diameter as the end of the rod, having the wire inserted firmly in its axis. The rod is bored, as the dotted lines at B denote, to receive the wire. The outside dotted lines indicate a case on the rod, choked at N. This is effected by stretching a piece of strong cord, a single turn of which is passed round the case at N, compressing it firmly and leaving a bore of the same size as the wire between the rod and the cap. In rolling a case to be choked, the paper should be used in pieces, each piece wide enough to make about 3 thicknesses when rolled over the rod, and the choking done after each piece is rolled. When finished, the rod is withdrawn from the mouth of the case, and the cap and wire from the other end.

2053 To Choke Firework Cases 29

2054. Composition for Rockets

2054.    Composition for Rockets. For 2 ounce rockets: - Mix 541/2 parts nitre (saltpetre), 18 parts sulphur, and 271/4 of charcoal, all in fine powder. Sift through lawn. For 4 ounce rockets : - 64 parts nitre, 16 parts sulphur, and 20 parts charcoal. For 8 ounce to 1 pound rockets : - 623/4 parts nitre, 15f parts sulphur, and 211/2 parts charcoal. For rockets 3/4 inch in diameter: - 16 parts nitre, 4 parts sulphur, and 7 parts charcoal. For rockets 11/2 inches in diameter use 1 part more nitre, and for still larger rockets, another additional part nitre. By using 1 part less charcoal, and adding respectively 3, 4, and 5 parts fine steel filings, the above are converted into brilliant fires; or, by using coarse iron filings, and still less charcoal, they become Chinese fire.

2055. Chinese Fire for Sky Rockets

2055.     Chinese Fire for Sky Rockets. If 3/4 inch or under, nitre, 16 parts J charcoal, 4 parts; sulphur, 8 parts; cast-iron borings, 4 parts. Mix. Or: If, over 1 inch and under 2 inches bore, nitre 16 parts; charcoal, 4 parts; sulphur, 4 parts ; iron borings, 5 parts. Mix.