The foregoing remarks will serve to explain how it is that powder varies so much in strength and quickness of fire. If the elements are imperfectly incorporated, the powder can never be equal to that which is properly made; and the manufacturer, having ascertained the best proportions in which to mix the elements, had better improve his machinery for incorporating them, rather than his knowledge of the chemistry of gunpowder. These observations will also serve to explain the apparent anomaly, that the French, and some of our other continental brethren, are held to produce a much inferior sporting gunpowder to that which is manufactured in old England.
Gunpowder is now made by all the sporting gunpowder manufacturers from No. 1 to No. 5 grain; and it appears certain that a further increase in the size of the grain would be advantageous; for many years of patient and laborious experiment clearly show, that the old notion of gunpowder being blown out of an ordinary sized gun in an unburnt state, is one of the “purest of vulgar errors:” such a thing indeed cannot possibly happen unless the powder be bad, or the gun _imperfectly made_, or injudiciously charged.
I am satisfied that I am under rather than over estimate, when I assert that six drams of ordinary sporting gunpowder may be beneficially and completely exploded in a barrel of 14 bore, 2 feet 6 inches long, with a resisting projectile one ounce in weight above it. This, however, being more than a double charge for such a gun, cannot be pleasantly practised; and it is only asserted by way of argument.
Assuming, then, for argument’s sake, that six drams of gunpowder are exactly consumed in passing from the breech to the muzzle of a gun 2 feet 6 inches long, and that the shot, therefore, acquires its greatest velocity as it leaves the muzzle, it follows that the ordinary charge of 2-1/2 drams will be wholly consumed before it has traversed half the length of the barrel, and consequently the charge of shot must here acquire its greatest velocity. It is certain, then, that the shot must travel the latter half of the barrel at a diminished velocity, and its velocity must continue to diminish as it passes up the barrel; for two obvious reasons--1st, The column of air in front of the charge is more condensed, and thus offers a greater resistance to the exit of the charge; 2nd, The velocity is continually diminished by the increased friction of the charge against the barrel.