1. This is a hydraulic and electrically operated unit, intended for compression tests on concrete specimens including rocks and various other materials. 

2. The machine consists of a steel cross head and cast iron base with two pillars connecting the base and cross head by means of nuts. The hydraulic jack is fixed to the base.

3. The upper part of the machine has a self-aligning action and is attached to a screw which passes through the cross head and can be raised or lowered for initial clearance adjustment.

4. The lower platen rests on the jack ram and is positioned with the help of a centring pin. Loading is accomplished by the upward movement of the lower platen. 

5. The motorised pumping unit is of plunger type and is connected to the jack by means of a steel connecting tube.