This octant has an ebony frame, flat brass index arm, and ivory name plate.
The ivory scale is graduated every 20 minutes from -3o to +99o and read by vernier with top-mounted tangent screw to single minutes of arc. It probably dates from the first half of the 19th century when there were several men of this name working at this address, making and marketing mathematical and optical instruments. It belonged to Bowdoin College.
Ref: Gloria Clifton, Directory of British Scientific Instrument Makers
1550-1851 (London, 1995), pp. 124-126.
