The locks, also, for the military service generally, are now receiving an important improvement by means of his labours, having been simplified in a remarkable manner. The action of the main spring is reversed, as shown by [fig. 411.]; thus rendering the whole mechanism more solid, compact, and convenient; while the ignition of the charge being effected by percussion powders in a copper cap, the fire of the British line will, in future, be more murderous than ever, as a mis-fire is hardly ever experienced with the fire-arms made at the Royal manufactory, under Mr. Lovell’s skilful superintendence.
FIRE-DAMP; the explosive carburetted hydrogen of coal mines. See [Pitcoal].
FIRE-WORKS. (Feux d’artifice, Fr.; Feuerwerke, Germ.) The composition of luminous devices with explosive combustibles, is a modern art resulting from the discovery of gunpowder. The finest inventions of this kind are due to the celebrated Ruggieri, father and son, who executed in Rome and Paris, and the principal capitals of Europe, the most brilliant and beautiful fireworks that were ever seen. The following description of their processes will probably prove interesting to many of my readers.
The three prime materials of this art are, nitre, sulphur, and charcoal, along with filings of iron, steel, copper, zinc, and resin, camphor, lycopodium, &c. Gunpowder is used either in grain, half crushed, or finely ground, for different purposes. The longer the iron filings, the brighter red and white sparks they give; those being preferred which are made with a very coarse file, and quite free from rust. Steel filings and cast-iron borings contain carbon, and afford a more brilliant fire, with wavy radiations. Copper filings give a greenish tint to flame; those of zinc, a fine blue colour; the sulphuret of antimony gives a less greenish blue than zinc, but with much smoke; amber affords a yellow fire, as well as colophony, and common salt; but the last must be very dry. Lampblack produces a very red colour with gunpowder, and a pink with nitre in excess. It serves for making golden showers. The yellow sand or glistening mica, communicates to fire-works golden radiations. Verdigris imparts a pale green; sulphate of copper and sal-ammoniac, a palm-tree green. Camphor yields a very white flame and aromatic fumes, which mask the bad smell of other substances. Benzoin and storax are used also on account of their agreeable odour. Lycopodium burns with a rose colour and a magnificent flame; but it is principally employed in theatres to represent lightning, or to charge the torch of a fury.
Fire-works are divided into three classes: 1. those to be set off upon the ground; 2. those which are shot up into the air; and 3. those which act upon or under water.
Composition for jets of fire; the common preparation for rockets not more than 3⁄4 of an inch in diameter, is: gunpowder, 16 parts; charcoal, 3 parts. For those of larger diameter: gunpowder, 16; steel filings, 4.
Brilliant revolving wheel; for a tube less than 3⁄4 of an inch: gunpowder, 16; steel filings, 3. When more than 3⁄4: gunpowder, 16; filings, 4.
Chinese or Jasmine fire; when less than 3⁄4 of an inch: gunpowder, 16; nitre, 8; charcoal (fine), 3; sulphur, 3; pounded cast-iron borings (small), 10. When wider than 3⁄4: gunpowder, 16; nitre, 12; charcoal, 3; sulphur, 3; coarse borings, 12.
A fixed brilliant; less than 3⁄4 in diameter: gunpowder, 16; steel filings, 4; or, gunpowder, 16; and finely pounded borings, 6.
Fixed suns are composed of a certain number of jets of fire distributed circularly, like the spokes of a wheel. All the fusees take fire at once through channels charged with quick matches. Glories are large suns with several rows of fusees. Fans are portions of a sun, being sectors of a circle. The Patte d’oie is a fan with only three jets.