Three-Registered Machine Gun

This machine had lines of barrels, in three racks on a revolving framework. As soon as the top row of cannons had been fired, the next rack was loaded; at the same time a third rack was cooling off. This could well be argued as being the forerunner of today’s modern machine gun. Historians generally agree that Leonardo's ideas were as sophisticated as those of an artillerist in the mid-1800s!