An early 19th-Century lacquered brass and ebony octant, signed on the makers ivory plaque Spencer, Browning & Rust London with telescope mount, star telescope, mirrors, six shades, brass index arm with framed ivory vernier scale and clamp, the arc with engraved ivory scale divided 0°o-100°o, on three brass pad feet in stepped mahogany case with part trade label - 15¼in. (39cm.) wide.