Accession No
3756
Brief Description
circumferentor, Stanley, 1900 (c)
Origin
Gt. Turnstile; Holborn; London; England
Maker
Stanley
Class
surveying
Earliest Date
1900
Latest Date
1900
Inscription Date
Material
metal (brass, silver); wood
Dimensions
box length 285mm; breadth 175mm; height 101mm
Special Collection
Provenance
Purchased from Tesseract, Hastings-on-Hudson, New York, USA, 1990.
Inscription
‘Diff. of Hypo. & Base’ (on compass lid)
‘Stanley,
Gt. Turnstile Holborn
London
7317’ (on compass rose)
Description Notes
Brass circumferentor. Silvered compass box, graduated 0-90 between each cardinal point and 0-360 around edge, by 1 degree divisions. Needle is lockable. Transverse spirit level mounted on limb, which extends to support folding sights. Brass cover for compass box has a scale marked on it. Socket and clamp for attachment to tripod base. Contained in a wooden case.
Condition: good (wire on one sight broken); complete.
References
Events
Description
The circumferentor is an instrument that derives from the reverse side of an astrolabe. It is used to measure horizontal angles, or vertical angles by suspending the instrument from its shackle.
The circumferentor was described by Arthur Hopton in 1611, though passing references had been made to it in earlier works. It became one of the standard pieces of equipment of the surveyor throughout the 17th and 18th centuries.
31/08/2006
Created by: updated by Ruth Horry on 31/08/2006
FM:44585
Images (Click to view full size):
