Antique Octant by Spencer Browning & Co, London.


A fine early 19th century navigators Octant made by Spencer Browning & Co, 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 -2 degrees to 107 degrees. It is further divided into 20 minutes of arc and can measure angles of up to 90 degrees.

Double-hole sighting pinnula with swing cover. Concealed pencil compartment with screw on ivory cap.

The scale is also engraved SBR (Spencer Browning & Rust) near the 50 degree mark, this indicates that this Octant's ivory scale was made by Spencer Browning & Rust who produced navigation instruments from 1784 to 1840.

This Octant has the early flat and unbraced 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 & Co, London. - Spencer Browning & Co are recorded as making navigational instruments from 1840 to 1870.

Height of Octant: 12 inches / 30 cm, Radius of Octant: 9.5 inches / 24cm. There is no box with this Octant. 

Rear view of antique Octant. 

Close up of the antique Octant scale and SBR initials (Spencer, Browning & Rust) engraved on the scale. 

Close up of the antique Octant Vernier scale.  

Close up of the Antique Octant manufacturers plate, Spencer. Browning & Co, London. 

Close up of the antique Octant components. 

Close up of the antique Octant components. 

Close up of the antique Octant components. 

Close up of the antique Octant components.