Physics · Unidentified

Accession Number: 2017.ph.738


This is a black metal box, with two additional metal plates. The box is made out of plates of metal that is painted with a black, mottled surface. The box is open on one square side. Two plates of the correct size to cover this hole with matching screwholes to holes in the edges of the open face can be affixed here, closing the box. One of these plates has a round hole cut in the centre, and two smaller holes either side of this, that have been covered on the inside face by strips of tape. There is also tape residue visible on the exterior.

On the opposite face to the open side the box is closed by a larger plate. This has holes around the rim so the instrument can be fixed to something. On the inside of this plate, sandwiched between the other walls and the larger plate there is a sheet of cork, cut to fit the dimensions of the box. There are two small holes cut through both the cork and the back plate. Affixed to the rear of the larger plate there is a rim of cork around the edge. There is also two metal flaps that are bent.

The inside corners of the box have been sealed with tape; this is now mostly decayed and mostly loose; however Tucked inside the box there are three large grey resisters, soldered together in a chain. Each of these is labelled: “Type AB 300 OHMS”. Also in the box are two strips of tape with labels stuck inside. One reads: “10,000 megohm resistor for emission spectra”, the other “2,000 megohm resistor for absorption spectra”.

With this object there is a narrow flat plate with a knob on one side in the centre of one side, and a heavier broad smaller plate affixed to the other. Also there is a a small ziplock plastic bag, empty.

Primary Materials: Metal: Iron Alloy, Wood: Cork


Printed on each of the resistors: “IRC TYPE AB 300 OHMS”

On the tape labels: “10,000 megohm resistor for emission spectra”
“2,000 megohm resistor for absorption spectra”

Dimensions (cm):

Length = 14.6, Width = 13.6, Height = 6.5


Unknown, but labels indicated a potential use in spectrometry.


Poor: Object is both incomplete (intended as an attachment to a larger piece of apparatus) and in a state of disassembly. The pieces of tape are badly degraded and brittle. The metal is in good condition, although oxidized where the surface has been disturbed, i.e. in drilled holes. The cork is warped and coming away from the metal.

Manufacturer: Locally made; Resistors: IRC

Date of Manufacture: c. Mid 20th Century


University of Toronto, Department of Physics