The Magnus or Robins effect on rotating spheres

Abstract

Robins showed in 1742 that a transverse aerodynamic force on a rotating sphere could be detected by suspending it as a pendulum. Differences of periodic time in conical pendulum motion with spin and orbit parallel and opposed have been found to give a reasonably accurate measure of the lift coefficient, and the results shown extend knowledge of the effect down to a Reynolds number of 2 × 103 and up to a ratio of 12 between the peripheral and translational velocities.