Apparatus to show the path of a projectile, 1762.

Path of projectile apparatus, 1762. A ball runs down the curved slope and is projected from the end. It leaves the slope with a certain horizontal speed, which is maintained as it falls. However, it also accelerates, in the normal way for a falling object. The combination of a steady horizontal speed and an accelerating downward motion produces a curved parabolic path. The apparatus was made by George Adams of Fleet Street for King George III.