O R D N A N C E. Although artillery weapons, equipment, such as wagons, caissons, and limbers, machine guns, rifles, small arms, hand grenades, har ness and ammunition of all kinds are in cluded in the general class of military supplies known as ordnance, this article will consider only the features of con struction of the artillery weapon and its mount.
Artillery weapons are of three types, guns, mortars and howitzers. Of each type there are various models, the style, size and power of which are de termined by the use for which the weapon is intended. Guns are of three main classes, field, siege and coast defense weapons. In the United States Army field guns are again classified. Those under six inches in diameter are known as light artillery and are operated by the field artillery, while every gun of more than six Inches is classed as heavy artillery, and is operated by the coast artillery corps. A gun is fired from a low angular muzzle compared to that of a mortar, the elevation frequently being as low as 15°, and seldom exceeding 40°, while a mortar is designed to fire with a muzzle elevation of 65° to 70°. The barrel of a gun is usually longer than that of a mortar of the same cali ber, and because of that fact, the ex panding gases from the explosion have a longer time to act and a higher muzzle velocity results from a charge of power of the same power. A siege weapon is either a large gun or mortar placed some sort of a mobile mount such as a caterpillar platform or a special railway mount. A howitzer is a short weapon
usually of comparatively light weight, and so designed that its projectile will have an abrupt fall.
It is a long step from the catapult of ancient days to the gun with which the Germans bombarded Paris from a dis tance of over seventy miles, but as a matter of fact real progress in ordnance has been comparatively modern.
In spite of the fact that gunpowder was known to China and the far east for years before it was known in Europe, credit should go to the West for the first use of guns as they are now understood. Little attention was paid to the design of the gun or to the strength of the .harge in early days, and the first models were frequently more dangerous to their crews than to the targets.
Early guns were made of wrought or cast iron or bronze, and gradually in creased in size and weight in order to secure greater strength. They were of course loaded at the muzzle and fired by many devices using springs, air or water have been introduced and many fected. In the French 75 millimeter gun, acknowledged the most successful field piece of the World War, its outstanding superior feature was its matic recoil mechanism.