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A rectangular wooden box with a top and base that are slightly broader than the sides. On the top of the box, there is a metal rod set flat on the wood. This can be rotated somewhat from a fixed point at one end between two protruding rods. This is labelled “Coarse Zero Adjuster Slide Scale for Final Adjustment”. On the front of the box there is a rectangular opening covered in glass on which there is a drawn a linear scale labelled 0 to 10 and -5 to 5. To the right of the scale on the side of the box is a knob for adjusting the scale.

There are two electrical terminals at the back of the instrument affixed to the side. On the left side is an inset male electrical plug, labelled “6 VOLTS”. A plastic tag affixed to the base at the front of the instrument can be rotated to it can be read or tucked away under the base of the instrument. This reads “Galvanometer CAT.No.4625 SER.No.53451 Sensitivity .0076 mw/MM resistance 962ohms PERIOD 2.06 seconds C.D.R.X4000Ohms Date 2/24/50 Rubicon Company Philadelphia.”

Accession Number: 2021.zoo.79

Alternative Name:

Primary Materials: Wood, Metal, Glass


Underneath the scale on the front of the box there are two tags reading “Made by Rubicon Co. Philadelphia Made in U.S.A.”. A tag on the bottom reads “Galvanometer CAT.No.4625 SER.No.53451 Date 2/24/50 Rubicon Company Philadelphia”

Dimensions (cm): Height = 19, Width = 19, Length = 25.5


Device for detecting and measuring small changes in electrical current. Reflected light impacts a small mirror and electromagnet are affixed to a thread suspended between the poles of a permanent magnet. Running a current causes the mirror to move, changing the direction of the light, which can be seen on the scale on the screen at the front of the instrument,.


Good. The corners and edges of the object show some minor signs of wear; the stain is worn, particularly on the right-front hand edge of the object. The glass dial screen is coming away from its frame on the left hand side at both the top and the bottom. The metal of the plug is slightly speckled. The black face of the “MADE IN U.S.A.” plaque is speckled.

Associated Instruments:


Rubicon Co. Philadelphia, Pennsylvania, USA

Date of Manufacture: 1950s


This object was donated to the IHPST in 1982 by the University of Toronto Department of Zoology. It had been collected by Zoology professor George F. Holeton (d. 1980) along with a number of other instruments, and was donated by John H. Booth.

Additional Information and References:

A letter from John H. Booth at the Department of Zoology to IHPST Professor Trevor Levere dated June 3, 1982 lists this instrument among a number that were donated from the collection of Professor G.H. Holeton (d. 1980) by John H. Booth. (UTSIC Archive, File 1982)

Historical Notes: