Accession No

4042

Brief Description

polarograph, by Cambridge Instrument Company Ltd., Cambridge and English, 1938

Origin

England; Cambridge and London

Maker

Cambridge Instrument Company Ltd.

Class

chemistry; laboratory apparatus

Earliest Date

1938

Latest Date

1938

Inscription Date

Material

wood; metal; glass; paper

Dimensions

length 525mm; breadth 230mm; height 200mm

Special Collection

Cambridge Instrument Company Collection

Provenance

Donated by the Cambridge Instrument Company.

Inscription

‘THE FIRST POLAROGRAPH
MANUFACTURED IN
GREAT BRITAIN
MAY 1939’ (attached card)
‘CAMBRIDGE POLAROGRAPHY
CAMBRIDGE INSTRUMENT CO. LTD.,
LONDON AND CAMBRIDGE
C251731’ (lid)
‘MILLIAMPERES
CAMBRIDGE
INSTRUMENT
Co LTD
ENGLAND’ (milliammeter)
‘RES. 1.11 OHMS
AT 8˚C’ (milliammeter)
‘No L97831’ (milliameter)
‘CAMBRIDGE INSTRUMENT CO. LTD ENGLAND’ (bulb holder)

Description Notes

Polarograph consists of potentiometer, galvanometer and camera enclosed in a wooden case with controls on the metal lid and on the sides of the case. The metal lid is hinged and has a chain to prevent opening too far. The window at one end reveals a printed card claiming the instrument as the first to be made in Britain. On removing this a ground glass scale calibrated 0 - 8 can be seen. The knobs on the side of the case by the window are used to control the drum holding the photographic paper. The larger knob is divided 0 - 25 around its circumference. On the lid of the instrument are two pairs of terminals labelled + 4v - and + ELECTRODE - , a milliammeter under a circular glass cover with pointer, movement etc.; the scale is ungraduated with zero (0 milliamp) and test (50mA) positions. Three knobs: one to adjust current, one to adjust sensitivity with a range of twelve sensitivities 0 - 1, one to adjust zero. Below there are four switches for lamp 1, lamp 2, battery and motor. On the top side is the lamp case which can be removed to reveal the bulbs.

References

Events