Accession No
3723
Brief Description
circumferentor, by Edward Spicer, Irish, 1770 (c)
Origin
Ireland; Dublin
Maker
Spicer, Edward
Class
surveying
Earliest Date
1770
Latest Date
1770
Inscription Date
Material
metal
Dimensions
box length 455mm; breadth 200mm; height 85mm
Special Collection
Provenance
Purchased from Tesseract, Hastings-on-Hudson, New York, USA, 1988.
Inscription
‘Spicer Dublin’ (centre of compass dial)
Description Notes
Irish instrument. Compass box and the sights can be removed from the long bar supporting the instrument on its ball and socket joint. Bubble on one arm. Fitted box.
Condition: good; 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:44591
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