 | - | No. ¹⁄₂ L G | - | Marked in yellow, is restoved. | ||
| No. 3 F G |
This red L G, F G, or S G, denotes powder entirely made of the cylinder charcoal, and is that which is now always used on service. The white L G being a mixed powder, is not so uniform as the other, and is therefore generally used in filling shells, or for such other purposes as do not require much accuracy. All powder for service is mixed in proportions according to its strength, so as to bring it as much as possible to a mean and uniform force.
French Gunpowder.—The French proof ball is of brass, and weighs 60 lbs. French: the diameter of the mortar 7 inches 9 points, or ³⁄₄ of a line, and has one line of windage. The chamber holds exactly 3 ounces; and their best powder must give a range of 90 toises, and their restoved powder a range of 80 toises, to be received into the service. But the powder they now make, when new, will give range of 100 and 120 toises; and Mr. Lombard calculates all his tables from experiments made with powder giving 125 toises with the eprouvette. The above dimensions and weights are all of old French standard.
Invention of Gun-powder, is usually ascribed to one Bartholdus Schwartz, a German monk, who discovered it about the year 1320; it is said to have been first used in war by the Venetians against the Genoese in the year 1380. Thevel says its inventor was one Constantine Anelzen, a monk of Friburg. Peter Mexia says it was first used by Alphonsus XI. king of Castile, in the year 1342. Ducange adds, that there is mention made of this powder in the registers of the chambers of accounts of France, so early as the year 1338; and friar Bacon, expressly mentions the composition in his treatise De Nullitate Magiæ, published at Oxford in the year 1216. Some indeed are of opinion, that the Arabians or the latter Greeks were the first inventors of gunpowder, about the middle ages of our æra; because its Arabic name is said to be expressive of its explosive quality.
Considerable improvements have lately been made in the composition of gunpowder by the Chinese.
Method of making Gunpowder. Take nitre, sulphur, and charcoal; reduce these to a fine powder, and continue to beat them for some time in a stone mortar with a wooden pestle, wetting the mixture occasionally with water, so as to form the whole into an uniform paste, which is afterwards reduced to grains, by passing it through a sieve; and in this form, being carefully dried, it becomes the common gunpowder. For greater quantities mills are used, by means of which more work may be performed in one day than a man can do in a hundred. See [Mill].
This destructive powder is composed of 75 parts nitre, 9 sulphur, and 16 of charcoal, in the 100.
The granulation of gunpowder is performed by placing the mass, while in the form of a stiff paste, in a wire sieve, covering it with a board, and agitating the whole: by this means it is cut into small grains or parts, which, when of a requisite dryness, may be rendered smooth or glossy by rolling them in a cylindrical vessel or cask. Gunpowder in this form takes fire more speedily than if it be afterward reduced to powder, as may be easily accounted for from the circumstance, that the inflamation is more speedily propagated through the interstices of the grains. But the process of granulation does itself, in all probability, weaken the gunpowder, in the same manner as it is weakened by suffering it to become damp; for in this last case, the nitre, which is the only soluble ingredient, suffers a partial solution in the water, and a separation in crystals of greater or less magnitude; and accordingly the surfaces of contact are rendered less numerous.
The detonation of gunpowder has been always an interesting problem in chemistry. Numerous theories have been offered, to account for this striking fact. But it is now very well settled, that the nitric acid is decomposed by the heat of ignition; that is oxigen, combines with the charcoal, and forms carbonic acid, while the nitrogen, or other component part, with steam from the water of crystallization, becomes disengaged in the elastic form. Berthollet found, that the elastic product, afforded by the detonation of gunpowder, consisted of two parts nitrogen gas, and one carbonic acid gas. The sudden extrication and expansion of these airs are the cause of the effects of gunpowder.
The muriat afforded by combining the oxigenized muriatic acid and potash, affords gunpowder of much greater strength than the common nitre, but too dangerous for use. For the method of making this salt, See Acid (Muriatic, oxigenized).