Machine Gun Design by Leonardo da Vinci
Leonardo's designs for weapons and other machinery are particularly interesting in hindsight, because the ideas he had are very much those that exercised engineers and inventors during the 19th and 20th centuries. He foresaw the importance in warfare of heavy and light artillery, breech-loading firearms and multi-firing mechanisms to increase the rate of shot, all of which emerged in the latter half of the 19th century. With his interest in flying machines and parachutes, he also foresaw the aircraft revolution of the 20th century. The only thing that prevented him from producing modern weapons in his own time was the too-primitive technology and, more probably, the conservatism of the military leaders of the day.
This version of a machine-gun is a remarkable invention, given the problems of production. How well it would have worked is difficult to say, but theoretically everything has been thought through to an extraordinary degree. Leonardo's responsive mind obviously saw the advantage of firearms in battle, and he could see the problems of the contemporary weapons. His immediate response was to search for ways to improve their efficiency and range of powers.