Brockbank & Atkins, London c1820

An interesting early 30-hour pocket chronometer by Brockbanks, London dating from circa 1807, later cased up as a marine chronometer by Brockbank & Atkins circa 1820.

The Brockbank family business was started by John and Miles Brockbank circa 1780, and passed to their sons around 1808. George Atkins was accepted into the partnership in about 1815, the firm then trading as Brockbanks & Atkins until about 1860 when the name changed to Brockbanks Atkins & Moore.

When the chronometer was cased up as a marine timepiece to improve its timekeeping the movement was updated and fitted with an Earnshaw spring detent, and probably a new balance and balance spring.

A new larger, silvered dial was also fitted at this time and is engraved Brockbank & Atkins London 646. The chronometer has gold hands.

The chronometer movement, originally cased as a pocket chronometer, has gilt plates with decorative engraved backcock and is signed Brockbank’s London No 646.

The chronometer has an Earnshaw spring detent escapement and a compensated balance. The spare holes in the movement plates indicate that the chronometer was originally fitted with a Peto cross detent escapement, an amplitude limiting device and a separate cock to hold the top of the balance spring.

The original 3-tier mahogany box has brass drop type side handles and a small ratchet winding key.

Box size 5¼ x 5¼ x 5½ inches high.

Stock No. C1059