Accession No

3358

Brief Description

electrostatic voltmeter, Lord Kelvin's patent, by Kelvin and James White Ltd., Scottish/English, 1905 (c)

Origin

Scotland; Glasgow or England; London

Maker

Kelvin and James White Ltd.

Class

electrical

Earliest Date

1905

Latest Date

1905

Inscription Date

Material

metal (brass, iron); glass; ebonite

Dimensions

height 310mm; breadth 220mm; depth 250mm box height 365mm; breadth 262mm; depth 309mm

Special Collection

Provenance

Transferred from Department of Engineering, University of Cambridge, Cambridge, England, 06/1986.

Inscription

‘VOLTS’ (dial)
‘LORD KELVIN’S PATENTS
MULTICELLULAR
VOLT METER No. 2808
KELVIN & JAMES WHITE
LIMITED
GLASGOW & LONDON’ (plate)
‘E L1. B4. L’ (added on front)
‘ZERO
ADJUSTMENT
DO NOT TOUCH’ (added to top)

Description Notes

Multicellular electrostatic voltmeter, horizontal scale model, Thomson type.
In black and silver metal case; horizontal glazed window showing white dial with mirror; non-linear scale, 0 - 120 volts; two terminals, ‘O - ON’ switch, clamp screw, and bubble level on horizontal surface of case; cylindrical upper part of case houses suspension mechanism and includes zero adjustment screw; three feet, two adjustable; glass cup at bottom to contain oil for damping (some oil present); with five-position resistance box, silvered metal with ebonite top (‘MULTIPLIER No. 82 KELVIN & JAMES WHITE…’); in wooden carrying case with hinged lid; bottle full of oil, labelled ‘(Castor) OIL FOR DASHPOTS’.

Condition: good (suspension intact); complete

References

Events