Ms.Yippity Yap...Have a boo at a Lewis Gun..
http://www.ku.edu/~kansite/ww_one/ph...5/imag0473.jpg
A standard Lewis Mk.1 of the type issued in 1915, note the drum magazine.
The Lewis gun was initially designed by Samuel MacLean and was then developed and perfected by Colonel I. N. Lewis, of the American Army. Lewis was unable to interest the American Army in the weapon and so he took his design to Belgium where he set up a company to manufacture it in 1913. In 1914, with the outbreak of the First World War most of the staff of the Belgian factory fled to Britain bringing their designs and some equipment with them. They then began production of the Lewis at the Birmingham Small Arms Company factory. The British adopted the Lewis gun as their standard light machine gun in 1915. It was the first truly successful portable machine gun of its type in the world. It is an air-cooled, gas operated design feeding from a top mounted drum magazine.
The Lewis gun was one of the first machine guns to be mounted in aircraft. The standard version was used as an observers weapon in multiple seater aircraft, often with the rifle butt stock replaced with a spade type grip to make it easier to hold when standing up in a bucking aircraft (a frightening experience at the best of times). A stripped version called the Mk. 2 was used as a main, forward aimed machine gun on aircraft such as the SE5a scout. On the SE5a it was mounted so that to re-load you have to stand up, pull the weapon down so that it is in front of you, remove one magazine and replace it with a fresh one, all the while holding the control column between your knees. It was also seen on many of the two seat British fighters of the 1920’s
See More here...
http://www.wwiitech.net/main/britain/weapons/lewis/