surveyor's compass
Date1720-1750
Inventory Number5241a
ClassificationSurveyor's Compass
Subject
Maker
Thomas Heath
Cultural Region
Place of Origin
Dimensions18 x 36.5 x 15.5 cm (7 1/16 x 14 3/8 x 6 1/8 in.)
dial diam: 15.5 cm (6 1/8 in.)
dial diam: 15.5 cm (6 1/8 in.)
Material
DescriptionThe compass has a silvered dial with a central foliage design. The eight principal cardinal directions are engraved on it, as well as four 90-degree quadrants divided in increments of 10 degrees. The needle is in the shape of a harpoon. The outer rim as a 0-360° scale divided in degrees. The frame has two fixed sight vanes, on which plumb lines can be attached for leveling purposes (missing here).
The left side of the instrument is three inches long and has two sets of engraved scales: one divided in 12 equal parts; one divided in 6 equal parts. Diagonals are added for precision readings. On the right side, four other scales (15, 20, 25, 30) are engraved for surveying purposes. The limbs on which are found all these scales have "wheat-ear" decorative borders.
The left side of the instrument is three inches long and has two sets of engraved scales: one divided in 12 equal parts; one divided in 6 equal parts. Diagonals are added for precision readings. On the right side, four other scales (15, 20, 25, 30) are engraved for surveying purposes. The limbs on which are found all these scales have "wheat-ear" decorative borders.
In Collection(s)
Signedon limb: T. Heath Fecit
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.
ProvenanceMrs. Endicott Smith found this in an attic in Chestnut Hill, Massachusetts. David Wheatland purchased it from Smith on November 3, 1976. Donated to CHSI April 1977.
Henry Winter
Date: circa 1850
Accessories: carrying case; leather bag; tripod (5186b)
Object number: 5186a
George Adams (I)
Date: 1750-1772
Accessories: carrying case; cover plate (missing)
Object number: DW0687
Antonius Giamin
Date: early 20th Century
Object number: DW0590
Charles Pool
Date: 1820-1835
Accessories: carrying case; ball-and-socket joint; extra needle; plumb bob; glass vial; brass plates
Object number: 5194
Jacques le Maire
Date: 1738
Accessories: case; plumb bob
Object number: 7416
