This was the principle employed by WW2-period British inventor Barnes Wallace when he developed the "bouncing bomb" used in the famous "Dam Busters" raid against the Ruhr District dams. He had been inspired by the story of a technique historically used by the British navy that bounced spherical canon balls off the ocean surface to achieve accurate hits against enemy ships. Wallace worked out the physics by bouncing marbles, steel spheres, and various sizes and shapes of balls across a pond and then a long trough before progressing to larger-scale experiments. Even solid steel balls would bounce across water.