According to Wikipedia, the Maxim gun was invented by Sir Hiram Stevens Maxim in 1884, and was the first recoil-operated machine gun. The mechanism of the Maxim gun employed one of the earliest recoil operated firing systems in history. The idea is that the energy from the recoil is used to eject each spent cartridge and insert the next one, in lieu of a locked bolt or a lever mechanism. This made it vastly more efficient and less labor-intensive than previous rapid-firing guns. Maxim established the Maxim Gun Company with financing from Albert Vickers (la), son of steel entrepreneur Edward Vickers. Finally, the company was absorbed into the mother Vickers company, leading first to the Maxim-Vickers gun and then, after Vickers' redesign, the Vickers machine gun.