Modulus of elasticity -is a measure of stiffness of a given material. It is defined as the ratio -for small strains -of the rate of change of stress with strain. A specially designed apparatus capable of high sensitivity and accuracy. Two cast metal rectangular frames hinged together parallel to each other to allow only vertical relative motion -with a spirit level fixed on a cross-bar pivoted across the frames for noting the reference point. One frame has vertical scale 10 - 0 - 10mm with a micrometer head along it reading to 0.01mm for adjusting the spirit level. Each frame has a self-centering chuck at its top for holding wires and load hooks at the bottom. Also included are ceiling bracket carrying a pair of chucks -a counterpoise weight and a set of two wires -one each of brass and steel. The relative displacement between the two frames can be known from the micrometer reading after adjusting the bubble of spirit level.