Induction Coil


Accession Number:


This is a large cylinder mounted vertically on a rectangular wooden base. The cylinder has a broader base and top; the base is black and formed of bakelite, or similar; the top is a light-coloured non-conductive material. Between these two sections is a coil of fine wire; this is hidden under a canvas-like covering, painted red. This cylinder is hollow, with a narrow circular hole down the middle. A metal rod with insulated copper wire coiled around its length with a handle at the top to enable easy removal fits into the hollow middle of the the outside cylinder. Directly above the coil and below the handle there are two small electrical terminals. This inner coil is also hollow and there is a rod of metal fitted through its core; this is removable.

On the wooden base, there are two electrical terminals connected by wires that run under the base to the external coil. A white marking, possibly an arrow, indicates that one of the terminals connects to the external coil.

Alternative Name:

Primary Materials:

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


Dimensions (cm):

Height = 24.5cm, Length = 25cm, Width = 17.5cm


When an electric current is run through one of the coils under certain conditions, it induces an electric current in the other coil. This induction coil is likely intended to be a demonstration model for students to explore this phenomenon.


Very Good: The wooden base of the instrument is chipped and scratched, particularly around the edges and corners. There are two holes drilled in the base that possibly indicate missing components or a base that has been reused. The cover of the outer coil is in pretty good condition, although there is a scratch on one side that has cut through the outer layer of canvas. In other places, the canvas cover has a loose thread. The top light coloured plate on top of the cylinder is scratched discoloured in places.

The metal components of the instrument are oxidized. The exposed top of the innermost rod is rusted, although the length that is normally enclosed in the cylinder is only slightly corroded.

Associated Instruments:

Manufacturer: Unknown\

Date of Manufacture: Late 19th or Early 20th Century


University of Toronto Department of Physics

Historical Notes: