Accession No

6132

Brief Description

Dollar integrating micrometer microscope stage, for petrological use, by Unicam Instruments, English, c. 1940

Origin

Arbury Road; Cambridge; England

Maker

Unicam Instruments Ltd.

Class

metrology; microscopes; earth sciences

Earliest Date

1936

Latest Date

1950

Inscription Date

Material

metal (steel, copper); plastic; paper; rubber; glass

Dimensions

Box: length 200mm; width 150mm; height 60mm

Special Collection

Provenance

Donated on or before 18/6/2007.

Inscription

DR DOLLARS INTEGRATING MICROMETER
(centre: on bar across drums)

PAT:APPLIC:NO 29874
NO 630
UNICAM INSTRUMENTS CAMBRIDGE (bottom, centre)

Description Notes

Dollar integrating micrometer microscope stage, for petrological use, by Unicam Instruments, English, c. 1940. [See Wh.6111 for prototype version by Dollar]

Manufactured version of the Dollar integrating micrometer microscope stage designed by Dr. A. T. J. Dollar, Fellow of Emmanuel College, Cambridge. Intended for the geometrical analysis of rocks.

Micrometer assembly has six drums, each marked circumferentially from 0-10cm in both directions with 1/10 divisions. Drums are turned by first pressing down the typewriter-style key for that drum, to release it from its rubber brake, and then turning the wheel on the right-hand side.
In the centre is the slide under which specimen would be placed, marked ‘LEFT HAND’ on its left and ‘CENTERING SLIDE’ on its right. Two metal bars can be swivelled to either hold in place or release the slide.
Three small, radially-disposed jaws hold specimen in place under slide, in the centre hole of the microscope stage
A turning key sits loose in the box.

Object history file contains collection of printed ephemera material including original patent application material and photographs.

Condition: good; complete

References

Events