A brass base approximately 18 cm in diameter. Resting on top of the base is a removable brass cylinder casing. There is a round flat glass window on the side of the cylinder casing, for looking at the mirror behind it. The round base is standing on three leveling screws. There are two metal terminals.
Accession Number: 2009.ph.194
Primary Materials: Metal, Glass
Old inventory number = “phy258”. On the base is a marking “T.F.”. The top of the cylinder casing is engraved “AYRTON-MATHER GALV’N PATENT”, “ROBT. W. PAUL”, “68, HIGH HOLBORN”, “LONDON, W.C.” Underneath the lid historic measurements of the galvanometer’s internal resistance are measured (about 320 Ohms). Records go from April, 1908 to June 22, 1922.
Dimensions (cm): Height = 19, Diameter = 18
For precise measurements of electric currents.
Robert W. Paul, 68 High Holborn, London, England. Patented by A
Date of Manufacture: prior to Dec, 1919
Provenance: From the collection of Dr. Martin Lee.
Additional Information and References:
Robert W. Paul on Wikipedia – http://en.wikipedia.org/wiki/Robert_W._Paul – “In December 1919, the Cambridge Scientific Instrument Company took over the smaller but successful Robert W. Paul Instrument Company and became The Cambridge and Paul Instrument Company Ltd. The name was shortened to the Cambridge Instrument Co Ltd in 1924 when it was converted to a public company.”