LONGINES, A FINE AND RARE YELLOW GOLD KEYLESS LEVER TWO-DAY ‘CHRONOMÈTRE’ DECK WATCH WITH GUILLAUME BALANCE AND POWER RESERVE SECTOR

This impressive and very well preserved high-precision deck watch is double numbered on the movement and therefore it is likely that it was destined for Observatory timing trial. Like those of other makers, the movements of Longines watches were double engraved with the movement serial numbers when the intention was to submit them for testing. Deck watches were navigational instruments and as such had to be extremely accurate with a known rate of variation.