Figure 74.—Theodolite used by Orange Warner Ellis about 1780 for surveying boundary between the United States and Canada in the area which is now Vermont. USNM 309596.
Greenough, Thomas (1710-1785), Boston, Mass. Surveying Compass, made of hickory with engraved paper compass card. Over-all length 11 ft.; dial 5-1/2 in. in diameter. Central medallion on card depicts man along shoreline using a Davis quadrant with a schooner offshore, with touches of red. Inscribed in gilt in band around central medallion: "Made and Sold by THOMAS GREENOUGH, Boston, New Eng." Used by Joseph Frye in 1762 for surveying his land grant in what is now Fryeburg, Maine. Loan from Laurits C. Eichner, Clifton, N.J., in 1957. USNM 315001. Figure 44.
(See also, Frye, Joseph, manuscript booklet of "Tables Useful for Surveying Land ... ")
Hagger, William Guyse, (C. 1748?-1830?), Newport, R.I. Backstaff, or Davis Quadrant, about 1760-1770, made of dark wood with scales and sights of boxwood, 25 in. long, 14 in. wide at large arc and 5 in. wide at small arc. Inscribed as follows: "Wm G. Hagger Newpt R. Island/For Mr——." The name of the original owner has been blocked out by the insertion of a piece of ivory. This quadrant was acquired from Mrs. Carola Paine of Bethel, Conn., in 1961. USNM 319029. Figure 59.
Davis quadrants signed by Hagger are in the Comstock Memorial Collection of the Rhode Island Historical Society (dated 1776); in the Shepley Library in Providence, R.I. (dated 1768); and in the Peabody Museum at Salem, Mass. (dated 1775).
Also in the U.S. National Museum is an unsigned quadrant (USNM 178975) that is almost identical in detail to the one signed by Hagger. It is the gift of A. R. Crittenden, Middletown, Conn. Another almost identical instrument, in the collection of the Franklin Institute, is signed "C. Elliott, New London, 1764"; it differs from the other two only in that a lens is combined in the middle sight.
Holbecher, John, (fl. 1738). Backstaff, or Davis Quadrant, of dark wood with boxwood scales and vanes. Length 25-1/2 in.; large arc 15 in. Inscribed "Made by John Holbecher/ For Capt. Joseph Swan—1738."
Holbecher is not listed as an English or American instrument maker, but it is believed that the instrument is American.