A vernier octant late 18th Century, made of ebony and brass with inset ivory scale divided 2½° - 0° - 100° on Ramsden's engine, the span with inlaid ivory plaque stamped Spencer, Browning & Rust, London with screw fitted ivory ended pencil within, three shades, two mirrors and pin-hole sight with fitted in stepped key-stone case marked inside lid John Steer 1788 and with an ornate brass lock-plate (incomplete) -- 14in. (35.5cm.) in length