English: Illustration from Riccioli's 1651 New Almagest showing the effect a rotating Earth should have on projectiles. When the cannon is fired at eastern target B, cannon and target both travel east at the same speed while the ball is in flight. The ball strikes the target just as it would if the Earth was immobile. When the cannon is fired at northern target E, the target moves more slowly to the east than the cannon because the ground moves more slowly at more northern latitudes (and hardly moves at all near the pole). Thus the ball follows a curved path over the ground, not a diagonal, and strikes to the the east, or right, of the target at G.