Accession No
2628
Brief Description
dumpy level with tripod, by Cooke, Troughton and Simms Ltd., English, 1950 (c)
Origin
England; York
Maker
Cooke, Troughton and Simms Ltd.
Class
surveying
Earliest Date
1950
Latest Date
1950
Inscription Date
Material
metal; glass
Dimensions
tripod height 1600mm; max diameter 120mm; level case length 240mm; breadth 120mm; height 180mm
Special Collection
Provenance
Purchased from Sotheby’s Belgravia, London, England; lot 271, 18/07/1980.
Inscription
‘COOKE, TROUGHTON & SIMMS LTD.
YORK ENGLAND.
No 365012’ (on telescope)
‘Vickers instruments 4.10.68’ (repair label in case)
‘BR W662’ (on case)
‘365012 Ex D.E. YORK. U.S.’ (in paint on case)
Description Notes
Metal alloy construction with grey finish. Telescope with internal focusing, inverting lens and adjustable eyepiece. Long bubble beside telescope viewed through microscope by eyepiece. Reflector below. Small circular bubble on axis of telescope. Tilting screw. Azimuth clamp and motion screw. 3 foot screws between parallel plates; (new cover for round bubble and one new foot screw). Base and metal lid with key fastening. Tripod with double legs, each with clamp and leather strap. Screw attachment.
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:43914
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