Bolton's Apparatus -HLSI
A steel frame mounted on a heavy cast iron base with leveling screws. Upper end of rod (under test) 900mm length and 5mm dia is clamped by a 3-jaw 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 two frictionless pulley. Freely sliding three circular scales graduated in single degrees can be clamped at any position. Three pointer for clamping to the test rod are provided. Complete with three test rods, strings and two scale pans, but without weight.