Accession No

2475

Brief Description

miners dial, by E. R. Watts and Son, English, 1931

Origin

England; London

Maker

E. R. Watts and Son

Class

surveying

Earliest Date

1931

Latest Date

1931

Inscription Date

Material

glass; metal

Dimensions

box height 334mm; breadth 223mm; depth 185mm

Special Collection

Provenance

Transferred from Department of Engineering, University of Cambridge, Cambridge, England, 05/1979. Purchased 1931.

Inscription

‘E R W & S No 22112’ (on dial face)

Description Notes

Compass box mounted on shaft through parallel plates with 3 foot screws. 8 point rose. Scale graduated 0-360˚ in single degrees. Locking screw for needle. Horizontal circle surrounding compass graduated 0-360˚ to 30’ of arc, read by opposing verniers and microscopes to 1’ of arc. Clamp and motion screws for horizontal circle and azimuth motion. Bubble inset into compass face; second at base of solid arm mounted on compass box and supporting vertical circle and telescope. Vertical circle rotates on a horizontal axis on the arm. Graduated 0-360 in single degrees. Read by opposing verniers and microscopes to 1’ of arc. Clamp and motion screw for vertical circle. Bubble mounted on vertical circle adjusted by clipping screws. Telescope; inverting; crosshairs. Rack and pinion focus moving the objective within fixed lens cover.

References

Events