A late 18th-century ebony octant, stamped on the bone-ivory makers plate W.H. Moralee, North Shields, with double pin-hole sight, three shades, the brass index arm 9.1/2in. (24.1cm.) radius, with vernier, tangent-screw fine adjustment and clamp, in stepped key-stone shaped oak case

細節
A late 18th-century ebony octant, stamped on the bone-ivory makers plate W.H. Moralee, North Shields, with double pin-hole sight, three shades, the brass index arm 9.1/2in. (24.1cm.) radius, with vernier, tangent-screw fine adjustment and clamp, in stepped key-stone shaped oak case

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