The investigation of rod is measured by a micrometer screw. The brass tube is 50cms x 2.5cm C.P. With inlet and outlet tubes for steam and opening for thermometer reading to 1°x 110°C. The binding posts are provided on the supports for connecting a bell, buzzer or galvanometer for indicating the exact point of contact of the screw. Provided with three rods of brass, iron and aluminium without belland battery.

For showing the difference in conductivity. Rod 300 x 18mm length x dia ½ of which is of brass and ½ of polished wood jointed together.