SPENCER, BROWNING & RUST (1778–1870), octant made of ebony, ivory, and brass Ebony frame with a brass sighting mechanism and vernier scale; ivory dial and index plate. The instrument is in fine condition and is marked with the firm’s name, “Spencer, Browning & Co. London,” and “SBR” intertwined on the vernier scale. This dual signature indicates a date of manufacture around 1782–1785, when the manufacturer changed its name to “Spencer, Browning & Rust” (SBR). England, late 18th century. Height: 26.5 cm No carrying case or accessories. William Spencer (1751–1816) and Samuel Browning (1752–1819) partnered between 1778 and 1784 to establish the Spencer & Browning & Co. manufacturing firm, which specialized in navigational instruments. In 1784, Ebenezer Rust (17..–1800) joined the company, and the firm became Spencer, Browning & Rust in 1781. The company, already renowned for its creations, experienced significant growth until 1870. Numerous museums and institutions house items from this manufacturer, which supplied equipment to various expeditions, such as that of Charles Francis Hall. CIC No. K/20260713/2477183.