RIGIDITY APPARATUS  

(DYNAMICAL METHOD)

It consists of an iron stand 900 mm length fixed on a 4 kg cast iron heavy base with two levelling screws each rod 12.5 mm thick .

A steel frame mounted on a heavy cast iron base with leveling screws. Upper end of the rod (under test) 900 mm length and 5 mm dia is clamped by a 3 law chuck and the lower end is clamped into the axis of a torsional drum which can be rotated by putting load in the scale pan passing over to frictionless pulleys. 

Freely sliding three circular scales graduated in single degrees  can be clamped at any position .   three pointers made of Perspex for clamping to the test rod are provided.   Complete with three other rods, strings and two scale pans, but without weights