Consists of hollow cylindrical brass tube of length 40cm long and 18mm diameter, open at both ends, so that two solid and two hollow brass cylinders, each of length 10 cm and same dia, when put end to end fill the hollow tube completely. The weights can be arranged in different configurations to yield different results and graduated with a scale reading from 0 to 15 cm on both sides with a Vernier to read up to 0.05 mm. Provided with a pin-vice fitted at the centre of the tube. A plane mirror is fixed to this point which is used a reference to count the number of oscillations. Designed to study & Determine the modulus of rigidity of material of given wire by dynamical method. Supplied with wall-bracket.