This instrument has a cylindrical brass casing with flat glass cover. The face consists of a dial with brass centre and a silver-coloured indicator needle. The scale and backing are hand-drawn. A roughly quarter-circle scale, graduated in single units, is marked in tens “0” through “50” . There are two brass knobs on the left and right sides of the casing.
This item was found with a wooden base and backing, upon which it could be mounted (2009.uc.61), though it is likely that this backing was used for other ammeters as well.
Accession Number: 2009.uc.15
Alternative Name: Ammeter, Amperes Meter
Primary Materials: Brass, Metal, Glass, Paper
On the face of the instrument: “AMPERE-METER; Carpentier; no. 730; Recalibrated May 25th 1893 by J.S.P. Phys Lab’t’y Univ. of Toronto; Keep away from similar Instruments on all Magnets”
On the left-hand knob: “65” Above this knob, there is “+”. Above the right hand knob, there is a “-”
Old Inventory Number = uc15.
Dimensions (cm): Diameter = 17.5 cm, Height = 12.5 cm
Measures electrical currents in Amperes.
Good. The metal of the casing is marked and scored with use. The backing of the dial has been replaced with a hand-written backing.
Associated Instruments: 2009.uc.61
Manufacturer: J. Carpentier, Paris
Date of Manufacture: c. 1880
For information on the manufacturer of this instrument, see this UTSIC blog post: <a href=https://utsic.org/2011/02/15/jules-carpentier-1851-1921-a-modern-maker/ >”Jules Carpentier (1851-1921): A Modern Maker”</a> by Erich Weidenhammer.
For information on J.S. Plaskett, the Department of Physics mechanician who recalibrated this instrument, see this UTSIC blog post: <a href=”https://utsic.org/2010/11/02/in-praise-of-small-instruments-j-s-plaskett-the-physical-laboratory-workshop-and-the-humble-resistance-box/”>In Praise of Small Instruments: J.S. Plaskett, the Physical Laboratory Workshop, and the Humble Resistance Box</a> by Ari Gross.
“J.S.P.” on the dial refers to J.S. Plaskett who was, in 1893, the mechanician at the University of Toronto Physics Department.