Accession No

3670

Brief Description

dumpy level by Troughton & Simms, 4/4 19th C

Origin

London; England

Maker

Troughton & Simms

Class

surveying

Earliest Date

1875

Latest Date

1900

Inscription Date

Material

metal (brass, metal alloy, white metal); glass; liquid; wood (mahogany); hide (leather)

Dimensions

length 335mm; breadth 145mm; height 205mm box length 410mm; breadth 172mm; height 262mm

Special Collection

Provenance

Purchased, 1988.

Inscription

‘TROUGHTON & SIMMS
LONDON’ (standard beneath telescope)

Description Notes

Metal alloy telesocpe with rack and pinion focusing; ray shade; sliding tube adjustment for eyepiece. Bubble mounted over telescope and graduated in 0.1 inch; transverse bubble near objective lens. The telesocpe is mounted a tripod head with 3 brass levelling screw set between two tribrach plates; the lower plate has a screw fitting for the tripod. Knurled screw controls azimuth motion.
Fitted mahogany box with brass hinges and lock (no key); leather carrying strap stored inside box.

Condition good; 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:44209