A gas operated fully automatic air cooled aircraft machine gun invented by Col. Isaac Lewis of the US Army. Highly distinctive in appearance, the original Lewis gun had a large, round ammunition magazine on top of the receiver and its barrel enclosed in a long, round aluminum tube. Developed as an assault weapon the original gun had a stock that was removed when modified for aircraft use. In its day the Lewis gun was a real innovation, weighing just 26 pounds against its competition, the Vickers machine gun at 68 pounds. The Lewis Gun was the first gun to be mounted on an airplane. A Bristol Scout had one mounted on the left side of the cockpit and angled out to miss the propeller. Wing mounts, ring mounts, and fixed mounts were developed to deploy the Lewis gun on several WW1 allied fighters. The early magazines held 47, 30 cal. Rounds, later magazines were up-graded to hold 94 rounds. The Lewis light machine gun was also an amazing World War I success story. By the spring of 1916, more than 50,000 Lewis guns were in combat use by allied Troops. Lewis machine guns were used well into the 1940’s.