An 18th-Century mahogany octant, signed on the makers ivory plaque Made by Thos. Howard Liverpool, Elijh Tower, with double 'pin-hole' sight and slide, back sight, mirrors, two shades, the mahogany index arm with venier (no scale) the arc with well divided boxwood scale divided 0°o-90°o on three wedge feet in stepped mahogany case - 20in. (51cm.) wide.