Accession No

3031

Brief Description

range calculator, by J. H. Steward, English, 1/2 20th Century

Origin

England; London

Maker

J. H. Steward

Class

calculating; military

Earliest Date

1900

Latest Date

1950

Inscription Date

Material

plastic (celluloid)

Dimensions

length 158mm; width 60mm

Special Collection

Steward collection

Provenance

Collection purchased from member of the Steward family, 1974.

Inscription

‘J.H. STEWARD LONDON’ (front)
‘UBIQUE PROTRACTOR 18 PR. Q.F.’ (reverse)

Description Notes

White celluloid rectangle with two bevelled edges and indentations along one long edge.
Obverse: shadow square in top left corner, with each side divided [0] - 10, numbered by 1. Along top edge a map scale for 1:20000, divided 0 - 2000, numbered by 1000, subdivided to 50. Remainder taken up with tables for calculating range dependent on various factors.
Reverse: correction tables for range. Small shadow square in top right corner, divided as before. Scale along bottom edge marked ‘degrees at 20´´’, divided 1˚ - 13˚, numbered by 1˚. Formulae and other aides-memoire on right hand side.

Discoloured and a little warped, complete.

References

Events