Accession No
1028
Brief Description
Surveyor’s cross-head, English (?), c. 1910
Origin
England (?)
Maker
Class
surveying
Earliest Date
1910
Latest Date
1910
Inscription Date
Material
metal (brass)
Dimensions
diameter 90mm; height 224mm
Special Collection
Provenance
Gift from the Department of Geography, University of Cambridge, from 1969.
Inscription
Description Notes
Surveyor’s cross-head, English (?), c. 1910.
Brass cylinder in two parts divided by silvered scales, lower cylinder with set of slits and window sights; scale 0 - 360 in single degrees. Read by vernier on upper scale to 2’ of arc. Upper cylinder with 2 sets of slit and window sights set mutually at right angles. Upper cylinder revolves horizontally over lower circle; controlled by tangent screws and pinion cylinder; 4 point rose; silvered scale 0 - 360º; locking bar. Clamp controls ball and socket joint. Second clamp controls azimuth motion of both cylinder
References
Events
Description
When field-surveying with a chain the cross-head enables the surveyor to locate features set off at right angles to the line of the chain. The cross-head is set up on a staff and the lower half of the head rotated until the points to be sighted at right angles are seen through the lower slits. Their compass bearing can be read off against the graduations on the silvered rim of the cross-head.
10/03/2009
Created by: Dr. Anita McConnell on 10/03/2009
FM:43365
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