The report, produced by crackers, is on the same principle as the report of a gun. The reports, which succeed each other, in crackers, formed in this manner, depends, as we remarked, on the turn of the paper, each turn producing that effect. Every part of the cracker, by this division, represents in fact a gun; and hence, as the combustion of one part necessarily succeeds that of another, we have, according to the number of turns, successive explosions.
Crackers, formed in this way, may furnish a variety in exhibitions. They may be either hung on a board, or set off on the ground. As to the report itself, it may be increased or diminished by enlarging or diminishing the size of each cracker, or division.
Crackers, as they are usually called, are nothing more than small cases charged with gunpowder. The Chinese squibs are crackers of this description. Some are four ounce cases; but the squibs, so named, hold about half a thimble full of powder. A piece of twisted match paper is inserted in the mouth of each of them. They are made of five or six turns of paper, and the last one is pasted and formed of red paper. The interior diameter is about a quarter of an inch.
Sec. III. Of Single Reports.
Cases for reports are generally rolled on one or two ounce formers, and seldom made larger, except on particular occasions. They are from two to four inches in length, and are formed of thick paper. Having rolled a case, pinch one end, quite close, and drive it down. Then fill the case with grain powder, leaving sufficient room to pinch at the top. Before it is pinched, a piece of paper is to be put on the powder at the top. Reports are fired by a vent bored in the middle, or at one end. Among the portable Chinese fire-works, reports form usually a large number. They are closed with clay, which is perforated to admit the match and priming.
There are a variety of compositions, used to produce the appearance of stars. Thus, there are stars of different colours, which also produce tails of sparks, scintillations, more or less vivid, &c. and are calculated for particular exhibitions. The serpent stars, however, have a different object, namely, to imitate a star at first, and afterwards a serpent.
The cases for serpent stars are choaked half an inch lower than the common kind; and, after filling the hole with meal powder, the following composition is put in. It is finished, but without the operation of choaking, by adapting a piece of quickmatch, and adding more priming powder.
Composition for serpent stars.