Apparatus for demonstrating the elasticity of a spring or wire, 1762.

The material to be investigated could be stretched and screwed between plates attached to the two prominent ends projecting at right angles to the board nearly three feet apart. When weights were added to the plate which is attached to one pulley, they move the test material downwards. This turned the other pulley which moved the index finger over the dial. This apparatus was made by George Adams of Fleet Street, instrument maker to the king.