Accession No

4402

Brief Description

American Y-level by P.H. Temple, c. 1840

Origin

Maker

Temple & Booker

Class

surveying

Earliest Date

1840

Latest Date

1840

Inscription Date

Material

metal (brass, silver); glass

Dimensions

length 495mm; breadth 130mm; height 200mm

Special Collection

Provenance

Purchased from Christie's in Lot 130.

Inscription

‘P H Temple
MAKER
Boston
No.40’ (on limb)

Description Notes

Brass surveying level. The telescope has rack and pinion focusing, the level has a graduated silver scale located by twin Y-supports and clamps on the shaped limb with 4 screw tripod attachment, adjustable by tangent screws.

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:44543