Hagger Backstaff

The frame of this instrument is rosewood, while the arcs, brace, and vanes are boxwood. The frame is inscribed "Wm. G. Hagger Newpt R. Island For M–" and "364." The "364" inscribed on the back of the larger arc is probably a serial number, indicating that this instrument dates from around 1773.
William Guyse Hagger (1748-1832) was an instrument maker in Newport, Rhode Island, until the Revolution, when British troops occupied that city.
Ref: Deborah J. Warner, "Davis Quadrants in America,"Rittenhouse 3 (1988): 23-40, on 32-33.
Currently not on view
Object Name
date made
ca 1773
Hagger, William G.
overall: 17.5 cm x 68 cm x 39 cm; 6 7/8 in x 26 25/32 in x 15 11/32 in
place made
United States: Rhode Island, Rhode Island, Newport
ID Number
catalog number
accession number
Measuring & Mapping
See more items in
Medicine and Science: Physical Sciences
Data Source
National Museum of American History, Kenneth E. Behring Center
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