AMMUNITION, a term applied to the ordnance stores used in the firing of guns of every sort and caliber. The term includes gunpowder, projectiles, primers, and accessories. The term "fixed ammunition" is applied to the condition when powder, projectile, or primer are combined in the single piece, so as to be ready for firing when placed in the gun. It is also employed in the case of ammunition for large guns, in which the powder is inclosed in a metal rim or groove around the base which is seized by the extractor in removing the empty case after firing.
lie case which is primed, but is loaded separately from the projectile. This type of ammunition is now seldom used. The ammunition used in heavy guns is almost always fixed for calibers of less than 4 inches. The metallic cartridge ease employed for fixed ammunition is usually made of brass of the best qual ity stamped from sheets or plates of varying thickness. The cases have a For guns of larger caliber, the propel ling force, which is gunpowder, is in closed in bags made of cloth. The charges are divided into sections when the weight of the complete charge is more than 100 pounds.
The charges are ignited by primers which are of four types: percussion, friction, electric, and percussion and electric combined. The ammunition sup ply for the army of the United States includes ammunition for small arms in cluding rifles, machine guns, and pistols, and ammunition for the Field Artillery. In the United States the ammunition for the Field Artillery, prior to the World War, included the following cali bers: 2.95-inch mountain gun, 3-inch company bodies of infantry and cavalry, and caissons which accompany artillery to the immediate neighborhood of the battle. Ammunition trains are held in the rear to insure a re-supply of combat trains.
The initial advantage obtained by Germany in the first years of the World field gun, and 3.8-inch field howitzers. In the case of these arms fixed ammuni tion is used.
The problem of continual and suffi cient supply of ammunition is one of the most serious factors in war and was an especially difficult solution in the World War in which vast quantities of ammunition were expended. The supply
is maintained by combat trains com posed of ammunition wagons which ac War were to a large extent due to the immense store of ammunition which had been prepared and held in reserve. Thus these years resulted in an industrial as well as a military combat between Germany and the western Allies. The Entente Powers soon recovered from this disadvantage and by 1916 possessed the advantage in artillery and ammuni tion. This preponderance was even more marked in 1917 and continued throughout the war. The French out put of projectiles for the 75 mm. field pieces had increased, by 1917, 40 times, compared with the output at the begin ning of the war. The production of large-caliber projectiles had increased 90 times. The case of Great Britain was even more remarkable. The out put in a single day of shells for heavy guns and in a week for field howitzer and 3-inch guns in 1917 equalled the production of these shells during the en tire first year of the war. At this time there were nearly 5,000 Government controlled ammunition plants in Great Britain, with over 2,000,000 employees.
The largest shells thrown during the World War were those fired from the long range cannon with which the Germans bombarded Paris. This gun had a range of 73 miles. The shell thrown weighed 330 pounds and had a bursting charge of 33 pounds. This was placed in two compartments separated by a metal diaphragm. The walls of the shell were very thick in order to withstand the shock of discharge. The total length was 4 feet, 2 feet 5 inches of which were ballastic cap to offset air resistance and cause the center of pres sure to fall in advance of the center of gravity.
For discussion of the types of am munition used in various types of ord nance, see ARTILLERY, MACHINE GUN, EXPLOSIVES, PROJECTILES, etc.
AMcEBA, a term applied to a proto zoiin which perpetually changes its form. It is classed under the rhizopoda. It is among the simplest living beings known, and might be described almost as an ani mated mass of perfectly transparent moving matter. The amceba diffiuens is sometimes called, from its incessant changes of form, the proteus.