Accession No

2442

Brief Description

plug-type Wheatstone Bridge, Post Office pattern, by Elliott Brothers, English, 1900-1925

Origin

England; London

Maker

Elliott Brothers

Class

electrical

Earliest Date

1900

Latest Date

1925

Inscription Date

Material

wood; plastic (ebonite, ivorine); metal (brass); wax

Dimensions

box length 263mm; breadth 190mm; height 170mm

Special Collection

Provenance

Transferred from Department of Physical Chemistry, University of Cambridge, Cambridge, England, 1978.

Inscription

“ELLIOTT BROS. LONDON / No. 745 / TEMP. 18 C. 1” (on top)
“ENGINEERING LABORATORY CAMB. UNIV.” (on inner box on ivorine plate, added)
“P.S. / B.A. UNITS” (on inner box on ebonite plate, added)
“Instr. No. 793 / 0” (on inner box on paper label, added)
“LEAVE LOOSE PLUGS IN BOX / LEAVE LID CLOSED” (on outer box inside lid on paper label, added)
“72” (on outer box on top of lid, added)
“DR J HOPKINSON / WESTMINSTER” (on outer box on bottom, added)

Description Notes

Plug type Wheatstone Bridge, Post Office pattern, made by Elliott Bros., 1900-1925; Rectangular wooden box with ebonite top, screwed to the inside of a second (added) wooden box with hinged lid and brass handle; six brass terminals; two tapping keys with ebonite handles; brass blocks with twenty-four plug receptors (including two marked INF’); twenty-four brass and ebonite plugs; three pairs of proportional coils of 10, 100, and 1 000 ohms, and sixteen coils fro 1 to 5 000 ohms, total 11 110 ohms; all twenty-two coils wound on brass and ebonite bobbins, wax coated, and fastened to underside of top plate.

References

Events