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Octant

Catalogue number:
PH*290534

Inscriptions:
"Made by Tho^s Ripley London For Fran^s Earle July 21^st 1784"

Dimensions:
radius 13.75 inches

Discussion:
This octant has a rosewood frame, flat brass index arm, and ivory name plate. The ivory scale is graduated every 20 minutes from -5^o to +95^o and read by vernier to 2 minutes of arc. Thomas Ripley was in business from 1765 to 1790, offering mathematical and optical instruments.  Caroline (Mrs. Alfred E.) Bates, a Washington socialite, donated this instrument to the Smithsonian in 1916.

Ref: Gloria Clifton, Directory of British Scientific Instrument Makers 1550-1851 (London, 1895), p.233.

Further Information:

Octant