Accession No

6228

Brief Description

Brass surveyor’s cross, in the shape of a sphere, in wooden case, 19th or early 20th century

Origin

Maker

Class

surveying

Earliest Date

1800

Latest Date

1925

Inscription Date

Material

metal (brass); wood (mahogany)

Dimensions

[box] height 107mm; width 102mm; depth 102mm

Special Collection

Provenance

Purchased from an individual seller at the 44th International Scientific Instrument Fair, Marble Arch, 20/04/2008.

Inscription

Description Notes

Brass surveyor’s cross, in the shape of a sphere, in wooden case, 19th or early 20th century.

Hollow brass sphere with hole in top and threaded screw hole in bottom. Brass handle screws into bottom hole, either pointing inside the sphere for storage or pointing out from the sphere for handling.

Eight thin lines are cut through the sides of the sphere, at exact 45o separations. Small holes are placed at the top and bottom of each line.

With cube shaped mahogany box.

Condition: good/fair (one large dent in side, several scratch marks); complete

References

Events

Description
The Surveyor’s Cross is a simple surveying instrument, used to establish angles of 45o and 90o when either setting out a site or taking measurements. It is used by taking sight-lines by holding the instrument up to the eye and looking through one of the slits. In total the instrument contains eight slits, each separated by exactly 45o.

This example is unusual in that it is in the shape of a sphere, rather than the more commonly found cylinder or octagonal shapes.
09/06/2008
Created by: Joshua Nall on 09/06/2008

FM:46701