Historical information
A type of instrument used in the 1900s to measure very low currents by sending beams of light to the mirror and reflecting this back onto a wall using the mirror as an amplifier. Small currents in V/A can display a displacement of a few inches on the wall. This instrument has to be balanced, hence the air bubble level and adjustable feet. The meter was scaled in degrees.
Physical description
Galvonometer with all brass body shell removable for initital adjustments. Two observation ports. Base with levelling feet.
