Produced by the Cambridge Instrument Co Ltd, England. Features a crescent dial, divided 30-0-30 with parallax mirror. Markings at left- RES 50.3 ohms; at right- No. Knife blade pointer, radical magnetic field mounted coil. Pointer arrestor mechanism with rear pin activation.
All mounted beneath a a substantial beveled crystal. Lacquered brass case has twin connections with engine-turning clamping knobs.
Backplate with tripod marked'No. Front section secured to the rear on bayonet fixing.Beautiful, high quality instrument for the detection of minute electrical emf originally created by the military during World War 1 for blasting and signaling. Features a spring-mounted universal pivot. Moving coil effectively floats on fine spring, protected by a plunge pin in the base that frees the coil on a flat, stable base. Height (When Standing): 6.0.