Pyrotechny is, properly speaking, the science which teaches the management and application of fire in various operations; but in a more limited sense, and as it is more commonly used, it refers chiefly to the composition, structure, and use of artificial fireworks. The ingredients are, 1. saltpetre, purified for the purpose; 2. sulphur; and 3. charcoal. Gunpowder is likewise used in the composition of fire works, being first ground, or, as it is technically termed, mealed. Camphor and gum benzoin are employed as ingredients in odoriferous fireworks. The proportions of the material differ very much in different fireworks, and the utmost care and precaution are necessary in the working them to a state fit for use, and then in the mixing. In this work wo cannot enter on the subject with a sufficient degree of minuteness to teach the method of manufacturing fireworks, and shall therefore content ourselves with a brief notice of the proportions of the materials in some of the more common and more interesting articles in use. The charges for sky-rockets are made of saltpetre, four pounds; brimstone, one pound; and charcoal, one pound and a half; or by another direction - saltpetre, four pounds; brimstone, one pound and a half; charcoal, twelve ounces; and mealed powder, two ounces.

These proportions vary according to the size of the rocket; in rockets of four ounces, mealed powder, saltpetre, and charcoal, are used in the proportions of 10, 2, and 1; but in very large rockets, the proportions are saltpetre, 4; mealed powder and sulphur, 1 each. When stars are wanted, camphor, alcohol, antimony, and other ingredients are required, according as the stars are to be blue, white, etc. In some cases gold and silver rain is required; then brass-dust, steel-dust, saw-dust, etc. enter into the composition; hence the varieties may be also indefinite. With respect to colour, sulphur gives a blue, camphor a white or pale colour; saltpetre, a clear white yellow; sal-ammoniac, a green; antimony, a reddish; resin, a copper colour.