Accession No

2557

Brief Description

alidade, Henderson’s rapid traverser, by E. T. Newton and Son Ltd., English, 1900 (c)

Origin

England; Camborne

Maker

E. T. Newton and Son Ltd.

Class

surveying

Earliest Date

1900

Latest Date

1900

Inscription Date

Material

metal; brass; oxidised brass; glass; wood; cloth; felt

Dimensions

circle diameter 227mm; telescope length 257mm

Special Collection

Provenance

Purchased from Peter Delehar, London, England, 10/05/1980. Purchased witht the aid of grant from Preservation fund administered by the Science Museum (PRISM).

Inscription

‘HENDERSON’S PATENT
RAPID TRAVERSER
MAKERS
E.T. NEWTON & SON LTD
CAMBORNE, ENGLAND.
S.M.’ (alidade)
trade label inside box

Description Notes

Brass circle divided [[0] - 360˚, numbered by 10˚, graduated to 30´; clamp for attachment to tripod. Oxidised cruciform brass alidade. Brass sights with screw attachment. Vernier plate at right angles reads scale to 1´. Clamp and slow motion screw on 4th arm. Edge of alidade bevelled and divided [0] - 4 on each side of fixed central screw. Long bubble level on alidade. Round bubble level on clamping arm. (White enamel zinc or celluloid disc fits below alided - missing). Vertical semicircle divided 90˚ - 0 - 90˚ on both sides, numbered by 10˚, divided to 1˚; Y bearings; vernier to 1´. Long bubble level in axis of Y bearings. Clamp and slow motion screw. Telescopic sight; rack and pinion focus moving eyepiece; cross hairs.
Spare sights.
Fitted box lined with green felt.
Plumb bob missing.

Incomplete (plumb bob and writing disc missing)

References

Events