Accession No

2032

Brief Description

induction coil, Ruhmkorff type, 9-inch spark, by Harry W. Cox and Company Ltd., 1st 1/4 20th Century

Origin

England; London; 47 Gray’s Inn Road

Maker

Harry W. Cox and Company Ltd.

Class

electrical

Earliest Date

1900

Latest Date

1925

Inscription Date

Material

wood; metal (brass); ebonite; ivorine

Dimensions

length 670mm; breadth 375mm; height 335mm

Special Collection

Cavendish collection

Provenance

Transferred from Cavendish Laboratory, University of Cambridge, 1974.

Inscription

‘HARRY W. COX & CO LTD
ACTUAL MAKERS OF X RAY &
ELECTRO THERAPEUTIC APPARATUS
47 GRAY’S INN ROAD
LONDON, W.C.’ (ivorine plaque on base)
‘H. W. COX & CO LTD
LONDON.’ (interruptor plate)
‘PATENT
NO 16926’ (interruptor plate)

Description Notes

Rectangular wooden box containing capacitor. Two pairs of brass terminals marked ‘Mercury break’ and ‘MAINS’ respectively. Six extra terminals mounted on ebonite plate on base between discharge rod pillars with brass connectors. Two-position ebonite and brass switch. Ebonite and brass discharge rods on two ebonite pillars (1 pillar broken and rod detached). Primary and secondary coils mounted on two ebonite standards and covered with ebonite sheet. Oscillating contact interruptor without Nieff hammer, mounted on ebonite plate.

Condition poor (one discharge rod pillar broken, coil covering broken); incomplete (1 discharge rod pillar missing).

References

Events