from
The Collaborative International Dictionary of English v.0.48
Vickers-Maxim automatic machine gun \Vick"ers-Max"im automatic
machine gun\
An automatic machine gun in which the mechanism is worked by
the recoil, assisted by the pressure of gases from the
muzzle, which expand in a gas chamber against a disk attached
to the end of the barrel, thus moving the latter to the rear
with increased recoil, and against the front wall of the gas
chamber, checking the recoil of the system.
[Webster 1913 Suppl.]