surveyor's compass
Date: 1850-1854
Inventory Number: 5129a
Classification: Surveyor's Compass
Subject:
Maker: Chamberlain & Ritchie (fl. 1850 - 1854)
Seller: Charles Gedney King (1808 - 1858)
Cultural Region:
Place of Origin:
Dimensions:
Without Sights: 7.5 × 37 × 14 cm (2 15/16 × 14 9/16 × 5 1/2 in.)
Case: 10 × 41 × 17.5 cm (3 15/16 × 16 1/8 × 6 7/8 in.)
Accessories: carrying case; tripod (5129b)
Description:
All brass instrument with two removable sighting vanes. Both have a narrow slit and circular apertures. There are two bubble levels, one on each arm positioned at a right angle and forming a "T", to level in both axes of the horizontal plane.
The silvered dial's face has eight cardinal points, with a fleur-de-lys for identifying North. Degrees are engraved on the raised scale (0-90°-0-90°), divided in half degrees, marked every five and numbered by tens. The needle is suspended by a jewelled steel point. The brass lifter arm is operated from underneath the instrument. The instrument is supported by a ball-and-socket joint and a tripod.
When not in use, the instrument is stored in a mahogany box, which has a glued label inside from another firm, Charles Gedney King. Perhaps the latter was the seller of this instrument.
The silvered dial's face has eight cardinal points, with a fleur-de-lys for identifying North. Degrees are engraved on the raised scale (0-90°-0-90°), divided in half degrees, marked every five and numbered by tens. The needle is suspended by a jewelled steel point. The brass lifter arm is operated from underneath the instrument. The instrument is supported by a ball-and-socket joint and a tripod.
When not in use, the instrument is stored in a mahogany box, which has a glued label inside from another firm, Charles Gedney King. Perhaps the latter was the seller of this instrument.
Signedon dial: Chamberlin & Richie, / Boston
on label, inside box: C. G. KING / MANUFACTURER & IMPORTER OF / Mathematical and Egineering Instruments, / No. 7 BROAD ST. (3D STORE FROM STATE ST.) / BOSTON
on label, inside box: C. G. KING / MANUFACTURER & IMPORTER OF / Mathematical and Egineering Instruments, / No. 7 BROAD ST. (3D STORE FROM STATE ST.) / BOSTON
FunctionThe surveyor's compass is an instrument used in surveying (or in navigation in rare cases) to measure horizontal angles, what is called bearing or azimuth.
For a nice discussion of this type of intrument, see the following website.
For a nice discussion of this type of intrument, see the following website.
Curatorial RemarksNote the different spellings of both makers' names in the signature of this instrument.
A blue painted triangle is found on the instrument and its case, which usually means it was used in the physics' department at Harvard University.
A blue painted triangle is found on the instrument and its case, which usually means it was used in the physics' department at Harvard University.
ProvenanceFrom the Jefferson Laboratory, Harvard University.