(Aluminium Frame) Dr. Searle's design. It is a famous instrument for determining the Young's modulus of a wire and is indispensable, where most accurate measurements are desired. The instrument consists of two aluminium frames connected by a link. The frames are fitted with two self centering chucks, with two wires (control and test wire) of equal lengths. An accurately graduated micrometer screw to read 0.01mm is fitted on a frame.