Accession No

3269

Brief Description

plate measurer for spectrograph, by Hilger and Watts Ltd., English, 3/4 20th Century

Origin

England

Maker

Hilger and Watts Ltd.

Class

optical

Earliest Date

1948

Latest Date

1975

Inscription Date

Material

metal (white metal, at least 3 other types); plastic (at least 4 types); glass

Dimensions

length 955mm; breadth 865mm; height 1470mm

Special Collection

Provenance

Transferred from Department of Earth Sciences, University of Cambridge, Cambridge, England, 09/1985.

Inscription

‘L99.3
64210’ (white metal plaque at rear of instrument)
‘HILGER
&
WATTS’ (plaque on lamp housing’

Description Notes

Large floorstanding grey-green painted metal casing with 4 levelling feet. Top of casing has 2 pairs of white metal rails on which move mountings for sample spectrogram and master spectrogram. Illumination lamp housed in arm mounted centrally at rear of casing and overhangs mountings for spectrograms. Lamp with condensers and 2 mirrors to direct light onto spectrograms. Longitudinal motion along length of spectrograms measured on scale divided 0 - [525]mm, numbered by 10 subdivided to 0.5, with vernier reading to 0.001. Magnifying lens to aid reading of vernier. Both sample and master can be adjusted in the lateral plane as well, using plastic knobs at front of plate mounts. Front of instrument has control panel. Panel at left hand side has white metal wheel (possibly for longitudinal motion of spectrograms?; plastic-topped knobs marked ‘motor drive’, ‘R’ numbered 5 - 25 numbered by 5 (with click stops), and another knob divided 1/1, 1/10, 1/100 (with click stops). At centre panel, knobs marked ‘Align’; ‘slit width’ with scale on knob divided 0 - 25 numbered by 5 subdivided to 1, and concentric outer fine scale divided 0 - [5] numbered by 1 subdivided to 0.5; ‘front focus’; ‘rear focus’; ‘slit height’ with click stops numbered 0, .1, .5, .7, 1.2, 1.6, 2.0. Control panel at right hand side with push buttons for ‘start’ and ‘ stop’; three position switch marked ‘projection lamp’ with positions for ‘off’, ‘low’, and ‘high’; toggle switch for ‘plate shift’ switching between ‘inching’ and ‘continuous’; toggle switches for ‘mains’ (with pilot light), ‘multiplier voltage’ (with pilot light), ‘display head’, ‘sync. plate and recorder’; knobs for sensitivity with coarse adjustment with click stops numbered 1 - 11, and fine adjustment with inner scale divided 0 - [10] and outer scale divided 0 - [100] (i.e. 1/100 - 1) numbered by 10 subdivded to 1; zero adjustment knob. Centrally located projection screen with knob for magnification compensation. 2 shelves (?) under control panels to either side of the projection screen. A small magnifying window is located to the right of the central control panel. At right side of main casing, emerges an insulated flex (to recorder ?) terminating in 6-pin plug; also plug sockets marked ‘mains’ and ‘recorder’.

References

Events