A Lord Kelvin type multicellular voltmeter Kelvin and James White Limited, Glasgow, circa 1900 The rectangular black japanned cast iron case with cylindrical post upstand over projecting top panel incorporating curved glazed mirror-backed scale annotated with unequal scale for 0 to 170 volts and with oval trade plate inscribed LORD KELVIN'S PATENTS, MULTICELLULAR VOLT METER No. 2403, KELVIN & JAMES WHITE, LIMITED, GLASGOW & LONDON, with insulated switch terminal inscribed ZERO to right hand side opposing looped connector to the other, the base cast with fixed rear foot and twin forward projecting brackets incorporating brass screw thread level adjustment supports around a glazed brass sleeve enclosing the lower part of the mechanism, 34cm (13.75ins) high. Kelvin, White (and Hutton) were chronometer and nautical instrument makers working both from 11 Billiter Street, London and 16, 18 and 20 Cambridge Street Glasgow from the late 19th century up to around 1925. The current lot is a type of electrostatic field voltmeter, the design of which was developed by Lord Kelvin in 1888.