surveyor's compass
Datecirca 1850
Inventory Number5203a
ClassificationSurveyor's Compass
Subject
Maker
E. & G. W. Blunt
1824 - 1866
Cultural Region
Place of Origin
Dimensions20.3 x 36.2 x 16.5 cm (8 x 14 1/4 x 6 1/2 in.)
blue board box: 23.5 × 39.4 × 20.6 cm (9 1/4 × 15 1/2 × 8 1/8 in.)
blue board box: 23.5 × 39.4 × 20.6 cm (9 1/4 × 15 1/2 × 8 1/8 in.)
Material
Accessoriesball-and-socket joint (5203b); tripod (5203c)
DescriptionThe instrument is made of brass with a silver dial. The two sighting vanes are removable. One is made of two narrow slits, the other of eight small circular apertures (four for the upper and four for the lower slits when looking through the latter). There is a small thumb knob to adjust the lifter arm.
On the South side, on the arm, is a circular universal bubble level. On the North side, an unusual round counter (0-10). The dial's face only has eight cardinal points. Degrees are engraved on the raised divided scale (0-360), divided in half degrees and marked to every ten. It is supported by a heavy ball-and-socket joint and a tripod.
On the South side, on the arm, is a circular universal bubble level. On the North side, an unusual round counter (0-10). The dial's face only has eight cardinal points. Degrees are engraved on the raised divided scale (0-360), divided in half degrees and marked to every ten. It is supported by a heavy ball-and-socket joint and a tripod.
Signedon arm, counter: E & G W Blunt / New York
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 intrument, see the following website.
For a nice discussion of this intrument, see the following website.
ProvenanceAlexander Johnston, Jr. (1815-1890), Wiscasset, Maine; David Wheatland acquired from Nelson J. Sanford, Damariscotta, Maine, July 30, 1970. Donated to CHSI February 2, 1977.
William J. Young
Date: 1820-1840
Accessories: ball-and-socket joint; carrying case
Object number: 5189
E. & G. W. Blunt
Date: 1844-1857
Accessories: handwritten tables and charts; carrying case; ball-and-socket joint
Object number: 5187
Samuel Thaxter & Son
Date: 1822-1831
Accessories: protective cushioned cloth; carrying case; ball-and-socket joint
Object number: 5180
Charles Pool
Date: 1820-1835
Accessories: carrying case; ball-and-socket joint; extra needle; plumb bob; glass vial; brass plates
Object number: 5194
J. Pool & Company
Date: circa 1850
Accessories: carrying case
Object number: 5200
H. M. Pool & Brothers
Date: 1853-1858
Accessories: belt grip; dial cover plate; lifter arm; carrying case
Object number: 5188
Alexander Megarey
Date: circa 1840
Accessories: cover plate for compass dial; plumb bob; ball and socket tripod (2005-1-0002), carrying case
Object number: 5199
William J. Young
Date: 1840-1855
Accessories: carrying case
Object number: 5190
Chamberlain & Ritchie
Date: 1850-1854
Accessories: carrying case; tripod (5129b)
Object number: 5129a
