Accession No
3771
Brief Description
Y level by William Simms, c. 1820
Origin
London; England
Maker
Simms. William
Class
surveying
Earliest Date
1820
Latest Date
1820
Inscription Date
Material
metal (brass); glass
Dimensions
case length 555mm; breadth 180mm; height 190mm
Special Collection
Provenance
Purchased from Christie's, London, 1990.
Inscription
‘SIMMS LONDON’
Description Notes
Brass, Y-shape level designed by Jonathan Sissons, where the telescope with surmounting bubble level can be removed from its bearings and reversed. The compass surmounts the telescope on 4 pillars. Fitted box inside leather case.
Condition fair; complete
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:44342
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