Thomson indicating wattmeter
Date1900-1920
Inventory Number0561
ClassificationWattmeter
Subject
Maker
General Electric Company
1892-present
User
Department of Physics, Harvard University
founded 1884
User
Paul Donaldson
fl. ca. 1920-1950
Cultural Region
Place of Origin
Place of Use
Dimensions10 × 16 × 14 cm (3 15/16 × 6 5/16 × 5 1/2 in.)
blue board box: 11.4 × 38.1 × 31.1 cm (4 1/2 × 15 × 12 1/4 in.)
blue board box: 11.4 × 38.1 × 31.1 cm (4 1/2 × 15 × 12 1/4 in.)
Material
DescriptionA General Electric indicating wattmeter in a fan-shaped black metal case, mounted on a square wooden base. The face of the meter has two heavy binding posts and three cylindrical bakelite posts (one marked, "75") and two push buttons. The instrument case has a protuding half-dome centered at the bottom, beneath which the instrument coil is housed.
The instrument has an irregular, fan-shaped display window, through which the instrument's scale and a needle-shaped indicator may be seen. The scale has two sets of calibrations, one from 0-75 [watts] and the other from 0-150 [watts]. Below the scale is an arc-shaped reflecting mirror.
From card: "Moving coil within fixed current coil. Small fan-shaped meter. Black metal case on rectangular wood base. Pair heavy current binding posts, 3 voltage posts (one marked 75) and press button. A small button to hold pointer on reading and knob on side to clamp pointer.
The instrument has an irregular, fan-shaped display window, through which the instrument's scale and a needle-shaped indicator may be seen. The scale has two sets of calibrations, one from 0-75 [watts] and the other from 0-150 [watts]. Below the scale is an arc-shaped reflecting mirror.
From card: "Moving coil within fixed current coil. Small fan-shaped meter. Black metal case on rectangular wood base. Pair heavy current binding posts, 3 voltage posts (one marked 75) and press button. A small button to hold pointer on reading and knob on side to clamp pointer.
Signedprinted at the base of the scale: THOMSON INDICATING WATTMETER / NO. 54615 / POTENTIAL LIMIT 150 VOLTS / CURRENT LIMIT 2 AMPS. / GENERAL ELECTRIC CO. / SCHENECTADY, N.Y. U.S.A. / PATENTED FEB. 11 '96.
Curatorial RemarksIdentical model 0423 (ser. no. 54614)
Patented Feb 11, 1896.
FunctionFor measuring the power consumption of a circuit. Alternating Current (A.C.).
ProvenanceFrom the Lyman Laboratory (Physics, Harvard) attic, 1/19/72. The blue triangle indicates its use in the Physics 3 course by Paul Donaldson in the 1930s. [1920s?].
Weston Electrical Instrument Corporation
Date: 1890-1920
Object number: 0313
General Electric Company
Date: late 19th-early 21st Century
Object number: 1997-1-1077
Siemens & Halske AG
Date: 1897-1903
Accessories: wooden box
Object number: 0272a,b,c,d
See also/See also
