Gun Powder
like many other socalled "modern inventions," gun powder appears to have been known to the Chinese several centuries before its invention in Europe, whether we ascribe the invention to Roger Bacon in the 13th century or to Friar Schwartz in the 14th. Its earliest well-authenticated use in warfare was at the battle of Crecy in 1346. Its use was rapidly extended and within a century after Crecy it had driven the bow and arrow from the field and relegated the lance and the battle axe to the secondary position of weapons for special emergencies only.
It is rather surprising that for more than five centuries, the ingredients first used remained unchanged. These were saltpeter, charcoal and sulphur;-charcoal to furnish the fuel for burning, saltpeter to furnish the oxygen needed to combine with the carbon of the charcoal, and sulphur to accelerate the rate of burning. The products of combustion are carbon dioxide and nitrogen, both gases, and the sulphate and carbonate of potassium, both solids. The expansive force of the gases is due not alone to the change from the solid to the gaseous state, but to the further expansion from the heat released by the change. The solids, being finely divided, produce the dense smoke which marks the firing of a gun loaded with what is now commonly called "black powder" as distinguished from the more modern smokeless powder.
Not every explosive substance is suitable for use as a "propellant" in a gun. To be available for such use, not only must the explosive develop great power but it must develop this power gradually, so that the projectile shall be started from its seat slowly and driven down the bore more and more rapidly as the pressure behind it rises to a maximum. If the full pressure were developed instan taneously, the gun would be ruptured before the projectile was started from its seat. Here we touch upon the difference between "explosion" and "detonation."
The explosion of a charge of powder in a gun, sudden as it is, is slow compared with the detonation of the "high explosives," nitro-glycerine, gun-cotton, etc. In one case we have an actual burning, the flame of which passes from grain to grain of the powder, occupying an interval which is perfectly appreciable and can be measured. In the other case we have a GUN POWDER shattering of the chemical structure and a re-arrangement of the atoms in a new structure, which is as nearly instantaneous as any process known to nature. It has been stated that for several centuries after the introduction of gun powder, its composition remained practically unchanged. This does not mean that no improvements were made. There are several factors besides the nature of the ingredients fluence its behavior. Of these, the most nts of the powder which inimportant are the size, shape and density of the grains. A large grain burns more slowly than a small one, and a dense grain more slowly than a light one. And slow burning means less violence of exof burning is still further affected by the sive development of pressure. The rate of burning is still further affected by the shape of the grain-a grain which exposes a large surface to ignition burning more rapidly than one of smaller surface. Taking adv artillerists designed many forms of powadvantage of these facts, der grains of varying degrees of effectiveness, but hampered always by the limitations of expansive power inherent in the chemical composition of black powder.
It was early recognized that certain of the high explosives would be ideal for gun powders if they could be tamed into the slow and regular burning needed for a propellant. It was realized not only that their power was enormously in excess of powder, but that, as the products of their combustion were entirely gaseous, a powder made from them would be pr practically smokeless. Many plans were tried for bringing them under control, but the problem was not solved until, toward bringing them under control, but the the end of the last century, the French chemist and artillerist Vielle discovered that the burning of gun-cotton could be perfectly controlled by making it into a colloid. A colloid is a hard, horn-like perfectly controlled by making it into a free from the cellular structure which, in simple gun-cotton, allows the flame of ignition to flash instantaneously throughout the mass. Singularly enough, it was found that one of the substances in which out the mass. Singularly enough, it was ing was another of the most violent of high explosives, nitro-glycerine. When mendously powerful explosives treated together by suitable processes, their combined power is preserved but are treated together by suitable processes, eliminated. The resultant substance is the their sensitiveness almost completely their combined power is preserved but most efficient of the modern smokeless powders. Another of the substances having the power of colloiding gun-cotton powders. Another of the substances hav- GUNTER is acetone, used in American and French smokeless powders. As has been already stated, none of these powders are absoproduce is lar dissipates quickly. The point should be produce is largely water-vapor, which is a matter of altogether secondary imlargely water-vapor, which portance, the real value of gun-cotton powders is a matter of altogether secondary impowder, and in the facility with which enormously greater than that of black they lend themselves to variations of powder, and in the facility with which brought out in the variegated shapes size and shape suitable for guns of various calibers. the United States Army and Navy. See EXPLOSIVES. and sizes of smokeless powders used in brought out in the variegated shapes ders lying in their power, which is This point is forcibly in England about A. D. 1604, by Robert GUNPOWDER PLOT, a plot, formed rank, goaded into excitement by the penal