Antique Octant by Spencer. Browning & Rust, London.

ANTIQUE OCTANT. No.5

A fine mid 19th century navigators Octant made by Spencer Browning & Rust, London with applied makers plate.

The Octant’s ‘T’ shaped frame is constructed from ebony with brass fittings and ivory scales. The arc scale is crisp and clearly engraved, reading from -4 degrees to 100 degrees and further divided into 20 minutes of arc. This Octant can measure angles of up to 92 degrees.

Double-hole sighting pinnula with swing cover. There is a set of three sunshades for the index arm mirror.

This Octant has a braced brass index arm, which is fitted with an ivory Vernier scale engraved from 0 to 20 and reading 1 minute of arc. There is a clamping screw to the reverse side with a fine adjustment tangent screw off to the side.

The ivory makers plaque is situated on the crossbar of the octant frame and is engraved Spencer Browning & Rust, London. Spencer Browning & Rust are recorded as working from an address in London from 1784 to 1840.

This Octant is complete with its original wooden, stepped keystone shaped oak box. (some repairs to the box are present)

Height of Octant: 13 inches / 33 cm,

Radius of Octant: 10.5 inches / 27cm.

The Octant preceded the design and development of the Sextant. The Octant was invented by John Hadley and Thomas Godfrey simultaneously in 1731.

The Octant gets its name from the Latin word Octans because it is an eighth of a circle (45 degrees) and can measures angles of up to 90 degrees.

By 1780 the octant had almost completely replaced all previous navigational instruments and was half the size of a Davis Quadrant.

In the early days the instrument frames were made from wood, usually Ebony with Ivory scales, however in the later years of Octant production the frames were made from brass and the scales were either Ivory or silver.

Clipper Maritime Antiques specialises in antique navigation instruments.

We offer a wide selection of top quality antique Sextant’s, Quintant’s and Octant’s, prices range from £300 to over £1000.

Price on request: Please Email us your enquiry or if you would like any help or advice about choosing an antique celestial navigation instrument.