Geared capstan, c 1820.
© Science Museum / Science & Society Picture Library
Model. Capstans were used for centuries to draw up ships' anchors. Turned by sailors pushing on the arms, a capstan acts as a wheel and axle, magnifying the turning force. The anchor is lifted by a rope or chain winding around the central axle. The arms on this example can be removed so that it takes up les room on deck when not in use. A ratchet in the base prevents it from turning back and allowing the anchor to fall.