full circle protractor
Datecirca 1775
Inventory NumberDW0285
ClassificationProtractor
Subject
Maker
George Burnthwaite
Cultural Region
Dimensions0.1 x 24.1 x 24.1 cm (1/16 x 9 1/2 x 9 1/2 in.)
Material
DescriptionThe protractor consists of a flat brass ring. There are 360 degree markings engraved around the circumference of the ring. Every tenth degree, beginning with 10, is also marked with the appropriate numeral. There is a brass cross bar fixed with one end at the 180 degree mark and the other end at the 360 degree mark. There is a small hole at each end of the cross bar.
Signedengraved on the cross bar: Geo. Burnthwaite Lamonby
Curatorial RemarksLamonby is most likely the city where this maker was working.
FunctionThe protractor is used for measuring and plotting angles. The protractor is placed above a figure or diagram with the center above the vertex of the angle and the diameter cross bar lined up with one of the angular arms. Users can then mark or measure the appropriate angle of the second angular arm using the engraved measurements.
ProvenanceDavid Wheatland purchased from Roux-Devillas Paris, July 7, 1967 (lot 7/39). Donated to CHSI 1985.
Elliott Brothers
Date: 1855-1870
Accessories: mahogany storage case lined with blue velvet
Object number: DW0460
William Cary
Date: 1790-1820
Accessories: original mahogany box (lid warped with cracks in two places)
Object number: DW0281
Keuffel & Esser Company
Date: 1900-1950
Accessories: original cardboard sleeve case
Object number: 1997-1-1625
Gabriel & Edward Davis
Date: 1830-1850
Accessories: circular mahogany case with one straight edge
Object number: DW0386
Troughton & Simms
Date: circa 1850
Accessories: walnut case (slightly warped and cracked; instrument fits in only one way and lid closely with slight difficulty); document concerning the cleaning of the instrument by John Losche in 1964 in the instrument file
Object number: 5461
Charles Bruning Company
Date: 1942
Accessories: plywood case; 3/4 inch wrench; black metal end pieces
Object number: 2003-1-0127