English: Precision regulator clock with electromagnetically-driven pendulum, by Alexander Bain, London, around 1845 (Deutsches Uhrenmuseum [German clock museum], Inventory No. 2004-162). One of the first electric clocks ever built. The pendulum was kept swinging by pulses of magnetic force from an electromagnet (solenoid) (visible, bottom) near the bob, powered by a battery, and controlled by switch contacts (visible, center) on the pendulum rod.