Callender and Griffith’s Bridge, Carry Faster Bridge and Potentionmeter combined in one instrument. It is an improvement over the potentiomenter. 50 cm long slide wire of 1 ohms resistance is calibrated into 100 equal parts. 14 coils are arranged in series in dial form each being of 1 ohms resistance, terminals arranged for appropriate working of different instruments, jockey sliding on brass rod, accuracy of adjustment ± 0.05 %
