potentiometer no.114 - 1890
potentiometer no.1012 - 1920
Crompton potentiometer
Evershed portable testing set
G.P.O. moving coil milliameter and voltmeter
portable voltmeter no.94282 - 1918, 0-600v.
Electrostatic voltmeter, disassembled to show parts
Evershed and Vignoles bridge 'Megger' testing set
