This watch is an example of the final development of pocket chronometers by Breguet. A single barrel with fusee have replaced the twin barrel calibre of the earlier type and the movement is of a more robust construction throughout. By the year 1818 when it was made, English chronometer makers, particularly Earnshaw, had begun to produce such instruments in substantial numbers and supply them to both merchant and naval shipping. The advantage gained by the use of an accurate timekeeper for navigaion was significant in the struggle between countries for trading superiority, and the French Navy was in no less a need of such watches and box chronometers than their English rivals. If such instruments could be made reliable and not over delicate, they could remain on board of a ship for longer periods between servicing. Furthermore with the end of hostilities after Napoleon's departure from France in 1815, the market was open for competition for the English chronometer makers; indeed, Bregueadapted certain features developed by such makers as Earnshaw and Arnold (his respect for the latter being well-known, to the extent that Arnold's son passed some time training with Breguet), but as is the case with this lot, he continued to demonstrate the unique style of the firm, particularly with regard to the elegant design of the dial.