The ammeter is mounted on a wooden base with a pair of vertical wooden supports to hold it upright.
The ammeter itself is a cylindrical unit affixed on its back to one of the vertical supports. The face of the ammeter is round, and there is an arc-shaped scale at the top of the face covered in glass. The scale is printed on cardboard calibrated for milliamps; however, the cardboard piece has fallen down into the front of the ammeter and is not entirely visible.
The back of the ammeter is a simple wooden board. A pair of wires emerge from the base of the board and run to one of two electrical terminals. One terminal is labeled with a plus sign (‘positive’) and the other a minus sign (‘negative’). A white arrow, pointing left , is printed on the flat wooden base next to the two terminals.
Also on the back of the board there is an handwritten ink inscription: “150-0-150 MILLIAMPERES, R=0.15”.
Accession Number: 2009.ph.164
Primary Materials: Wood, Metal, Glass, Cardboard
Old inventory number = phy1023. The face is engraved with “WESTON AMMETER”, “MADE BY WESTON ELECTRICAL INSTRUMENT COMPANY, NEWARK, N.J., U.S.A., NO. 55363.”
Height = 33 cm, Width = 27 cm, Length = 33 cm
Measuring amperage in an electrical circuit; possibly a demonstration device.
The scale at the top of the face has fallen down into the front of the ammeter and is not entirely visible.
Weston Electrical Instrument Company, Newark, New Jersey, USA.
Date of Manufacture: 1880-1937
Department of Physics, University of Toronto
Additional Information and References: