拍品 33
33
An ebony and brass octant signed on the makers plate Made by In° Gilbert on Tower Hill London Stephen Twycross 1793 the index arm 19¾in radius, with framed vernier scale, the arc divided 0°-90°, with mirrors, (sights and shades missing)

細節
An ebony and brass octant signed on the makers plate Made by In° Gilbert on Tower Hill London Stephen Twycross 1793 the index arm 19¾in radius, with framed vernier scale, the arc divided 0°-90°, with mirrors, (sights and shades missing)