Accession No
0387
Brief Description
Graphometer, by Canivet, 1772
Origin
Maker
Canivet
Class
surveying
Earliest Date
1772
Latest Date
1772
Inscription Date
1772
Material
metal (brass)
Dimensions
length 244mm; breadth 128mm; height 105mm case length 220mm; breadth 160mm; height 76mm
Special Collection
Robert Whipple collection
Provenance
Purchased by Robert Stewart Whipple from Gertrude Hamilton (trading as 'Mercator'), Paris.
Inscription
‘Canivet à La Sphére à Paris 1772’ (on semi-circle)
Description Notes
Graphometer, by Canivet, 1772.
Brass. Pierced semi-circle graduated 0 - 180 º clockwise and anti-clockwise in single degrees. Read by bevelled vernier on the rotating alidade to 5’ of arc. Combined slit and window (with wire) sights set at opposite ends of the diameter. Alidade with slit and window sights. Compass mounted centrally within semi-circle. Silvered 8 point rose graduated 0 - 90 - 0º in single degrees twice. Locking bar. Below centre of the diameter a ball fixed onto a socket and shaft for attachment to tripod.
Engraved with foliage decoration.
References
Events
Description
The graphometer is a surveying instrument used in the field to measure horizontal angles between two points, or between one point and a compass direction. Set up on a staff, with the fixed alidade aligned to survey point A, the moveable alidade can be aligned to point B, the angle between them being read on the graduated semi-circle.
Graphometers were more popular in France than in England. This instrument was made by the eminent craftsman Jacques Canivet (working 1743–74). It is signed ‘Canivet à la Sphère à Paris 1772’.
10/03/2009
Created by: Dr. Anita McConnell on 10/03/2009
FM:43322
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