These conditions led to the development of machine guns along two separate lines--the heavy type machine gun, which must be capable of long sustained fire, and the automatic rifle, whose primary requisite is extreme lightness. These requirements brought the ultimate elimination from ground use in France and in the United States of guns of the so-called intermediate weight as being incapable of fulfilling either of the above requirements to the fullest degree. The machine gun produced by the American inventor, Col. I. N. Lewis, was a revelation when it came to the aid of the allies early in the great war. This was an air-cooled gun which could be fired for a considerable time without excessive heating, and it weighed only 25 pounds, no great burden for a soldier. The Lewis machine gun was hailed by many as the greatest invention brought into prominence by the war, although its weight put it in the intermediate class, with limitations as noted above. Along in the first decade of the present century the Benét-Mercié automatic machine rifle was developed. This was an air-cooled gun of the automatic rifle type and weighed 30 pounds. Light as this gun was, it was still too heavy to be of great service as an automatic rifle, since a strong man would soon tire of holding 30 pounds up to his shoulder, and it was therefore in the intermediate class. The Germans had apparently realized better than anyone else the value of machine guns in the kind of fighting which they expected to be engaged in, and therefore supplied them to their troops in greater numbers than did the other powers, having, an early report stated, 50,000 Maxim machine guns at the commencement of hostilities. The Austrian Army had adopted an excellent heavy type machine gun known as the Schwarzlose whose chief feature lay in the fact that it operated with only one major spring. Such was the machine-gun situation, although incompletely set forth here, at the beginning of the great war. The nations, with the exception of Germany, had been slow to promote machine gunnery as a conspicuous phase of their military preparedness. In our Army we had a provisional machine-gun organization, but no special officers and few enthusiasts for machine guns. We were content with a theoretical equipment of four machine guns per regiment. The fact was that in no previous war had the machine gun demonstrated its tactical value. The chief utility of the weapon was supposed to lie in its police effectiveness in putting down mobs and civil disorders and in its value in other special situations, particularly defensive ones.