Accession No
2156
Brief Description
Y level by Troughton and Simms, c. 1880
Origin
London; England
Maker
Troughton and Simms
Class
surveying
Earliest Date
1880
Latest Date
1880
Inscription Date
Material
metal (brass, 1 other)
Dimensions
length 377mm; breadth 123mm; height 195mm
Special Collection
Provenance
Transferred from Department of Geography, University of Cambridge, Cambridge, England, 05/1969.
Inscription
‘Troughton & Simms
LONDON’ (on compass face)
Description Notes
Metal alloy with brass screws. Telescope with rack and pinion focusing moving objective lens. Cross-hairs. Detachable eyepiece cover. Bubble mounted benath telescope (no graduations).
Y supports. Compass mounted centrally. Scale on compass graduated to 10˚, upper scale divided to 1˚; locking bar. Axis clamp. Azimuth motion tangent screw. 4 foot screws between paralel plates.
References
Events
Description
The earliest form of modern surveyor’s level is the ‘Y’ level, which is a telescope supported in Y-shaped bearings. The telescope is held in place by pivoting straps, which allow the telescope to be reversed for back-sighting.
The Y level was unsuitable for difficult colonial terrain, requiring too frequent adjustments and the ‘dumpy’ level was developed in the early 19th century to overcome this. The dumpy level has a much shorter, fixed telescope, which turns about a central axis. It is compact, much more robust and is still being used in largely unaltered form on building sites and in road construction.
31/08/2006
Created by: updated by Ruth Horry on 31/08/2006
FM:42892
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