Menu Close

Galvanometer (Weston Electrical Instrument Company)


The device is encased in a wooden box with a glass top. Visible under the glass top is a large horse-shoe shaped metal magnet. In the centre of this horseshoe are the mechanics of the device, including a needle system. The needle is quite long and rotates from a point at the split end of the horseshoe. The needle points to a short slightly arc-shaped scale which is affixed towards the rounded end of the horseshoe. Above the scale is written “RES. 275.2 OHMS”, but it is otherwise unmarked.

A metal plate is affixed to the side front of the box of instrument, which gives maker and patent information. On the opposite side of the box plate there is a screw, above which is stamped “0”, and below “CORRECTION”. At the top of the device are two electrical terminals with threaded caps. Two short wires insulated in woven fabric emerge from the left side of the box.

Accession Number:

Alternative Name: Ammeter, D’arsonval/Weston Galvanometer

Primary Materials:

Wood, Metal: Iron Alloy, Metal: Iron (?), Glass, Metal: Copper Alloy


On the front of the device is a metal plate reading “Made by the WESTON ELECTRICAL INSTRUMENT CO., Newark, N.J., U.S.A.”, “Patented”, “Nov. 6, 1886, May 14, 1889, Apr. 29, 1890, Feb. 17, 1891, Dec. 19, 1893, Oct. 4, 1898, Jul. 18, 1901.”, “MODEL 324”, “No. 134”.

On the left and right side of the device is painted the numeral “II” and the letter “E”.

Dimensions (cm):

Height = 8.5 cm, Length = 18 cm, Width = 10 cm

Function: Measuring electrical current.


Very Good: The wooden case of the instruments is in good condition. The metal screws holding the lid on are somewhat rusty and the correction pin and electrical terminals are oxidized. The surface is marked by small scratches and dents. The glass lid of the case is intact. The internal mechanism of the instrument is in excellent condition. The emerging wires have been cut close to the instrument.

Associated Instruments:

Manufacturer: Weston Electrical Instrument Company

Date of Manufacture: 1901 – c.1920


From the collection of Professor Martin Lee.

Additional Information and References:

Historical Notes: