Electric Pointolite Lamp

Physics

Accession Number: 2009.ph.24

Description:

This object consists of two parts, a box and a lightbulb attached by a wire. The metal box has sides perforated by circular holes. There is a large switch on the top and two wooden knobs. The larger knob has a cord attached which is attached at the other end to a large light bulb with four internal electrodes, some of which have metallic blobs on the end. A power cord with wall outlet plug is attached to the smaller knob.

Alternative Name:

Tungsten Arc Lamp, Electrical Discharge Lamp

Primary Materials: Metal, Glass, Ceramic, Cloth, Wood

Markings:

On the lightbulb: “ROYAL EDISWAN
POINTOLITE
(PATENT)
600 CP”

Dimensions (cm):

Height = 16.2cm, Width = 20.5, Length = 20.5

Function:

This lamp is a system for providing a very bright point of light. The bulb is rated 600 Candle Power.

Condition:

Good. The metallic parts of the switch are corroded. The lightbulb is blackened towards the tip. The wire is degrading and shedding fibres.

Associated Instruments: 2009.ph.96, 2009.ph.98

Manufacturer: Ediswan

Date of Manufacture: c. 1930s

Provenance:

University of Toronto Department of Physics

Additional Information and References:

Compare with this similar object at the Yale Peabody Museum of Natural History: Pointolite Resistance, Ediswan and this object at the Oxford Museum for the History of Science: Electric Pointolite Lamp, by Ediswan.