radius 8.75 inches
The sextant belonged to the University of Pittsburgh, which was founded as
the Pittsburgh Academy in 1787. The frame is brass. The silvered scale is
graduated every 15 minutes from -3o to +143o and read by vernier with tangent screw and swinging magnifier to 15 seconds of arc. There were several instrument makers and dealers named
Chapman working in London during the middle decades of the 19th century. The
trade card in the wooden box is that of Benjamin Pike, Jr., who was in business
as an instrument dealer in New York from 1843 to 1864 and who probably imported this sextant into the U.S.