Accession No

2150

Brief Description

Y-Level, by E. R. Watts and Son, English, 1910 (c)

Origin

England; London

Maker

E. R. Watts and Son

Class

surveying

Earliest Date

1890

Latest Date

1920

Inscription Date

Material

metal (brass, alloy); glass

Dimensions

length 330mm; breadth 145mm; height 195mm

Special Collection

Provenance

Transferred from Department of Geography, University of Cambridge, Cambridge, England, 05/1969.

Inscription

on the telescope
ER WATTS & SON
LONDON 1606

Description Notes

Y-Level, by ER Watts & Son, c. 1910.

Metal alloy body with brass screws. Telescope. Focussing by rack and pinion on the objective lens. 2 vertical cross hairs. Sliding eyepiece. Y supports. Bubble mounted centrally, graduated in 1/10”, above compass graduated in half degrees. Prism sighting and locking screw on compass. Axis clamp. Brass housing for reaction spring to azimuth motion tangent screw with knurled head. 3 foot screws between parallel plates.

References

Events

Description
The Y-level is so called because the telescope rests on Y-shaped brackets. It is clamped by simple pins to enable it to be detached and reversed. When the level is placed on its tripod, readings to the targets ahead and behind are made without having to lift and rotate the tripod and instrument, thus speeding up the process and reducing the risk of error.

This level was made by E.R.Watts & Son of London in about 1910.

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.
10/03/2009
Created by: Ruth Horry, updated by Dr. Anita McConnell on 10/03/2009

FM:42891