Accession No
2447
Brief Description
dumpy level, by E. R. Watts and Son, English, 1919
Origin
England; London
Maker
E. R. Watts and Son
Class
surveying
Earliest Date
1919
Latest Date
1919
Inscription Date
25-5-1919
Material
metal (brass, nickel silver, 1 other); glass; wood
Dimensions
box length 380mm; breadth 185mm; height 163mm
Special Collection
Provenance
Transferred from Department of Engineering, University of Cambridge, Cambridge, England, 09/1979. Purchased by the Department of Engineering, University of Cambridge, Cambridge, England, in 1919.
Inscription
‘ERW & S’ (logo, in triangle)
‘E.R. WATTS & SON
LONDON
No 6404 L5’ (on level)
‘Patent No. 114036 - 1917 Regd. Design No. 665992’ (on level)
‘Instrument No. 6404 Date 25.5.19’ (label on box)
‘Constant 1.56ft. Lab No. LB’ (label in box)
Description Notes
Metal alloy body with black finish (rather worn). Brass eyepiece. Nickel silver screws. Axis clamp. Azimuth motion tangent screw. Rack and pinion focus and secondary eye focus. Bubble mounted on left side of telescope, hinged mirror over and white plastic reflector below. Bubble graduated in 1/10´´. Transverse bubble below eyepiece. Inverting telescope with cross-hairs and ray-shade. 3 foot screws in tribrach limbs. Fitted wooden box.
References
Events
Description
The ‘Dumpy’ level was developed in the nineteenth century to provide a compact robust instrument, suited to work on engineering construction and building sites. It was used in surveying and building to transfer, measure or set horizontal levels. In 1832, English civil engineer William Gravatt, who had worked with Marc Isambard Brunel (1769–1849) on the Thames Tunnel, was commission by Henry Robinson Palmer (1795–1844) to examine the South Eastern Railway’s route from London to Dover. Gravatt found traditional Y-levels too cumbersome for this surveying work, thus invented the more transportable and easier to use Dumpy level. The telescope, together with its bubble level, can be rotated round a central axis so that fore and back sights can be made without moving the instrument on its tripod. This level was made by E. R. Watts & Son of London in 1922 (active 1922/1926–1948).
17/03/2014
Created by: Allison Ksiazkiewicz on 17/03/2014
FM:42872
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