radius 9.75 inches
This octant has an ebony frame and reinforced brass index arm. The ivory
scale is graduated every 20 minutes from -2o to +104o and
read by vernier (without tangent screw) to single minutes of arc. A note written
by Capt. H. Flynn of Lowell, Ma. in 1891 traces the history of this octant back
to 1772. Stylistic concerns, however, suggest that the instrument was made in
the early 19th century. The College of the Holy Cross in Worcester, Ma., donated
it to the Smithsonian in 1965.