Very fine, 14K gold, keyless pocket watch with split-seconds chronograph and instantaneous 30-minute register. Case four-body, demi-bassine, polished, split-seconds gold push-button on the band at 11 o’clock, co-axial button in the crown for start/stop and return-to-zero of the chronograph. Hinged gold cuvette engraved with the Grand-Prix prize medals. Dial white enamel with bold painted dauphine numerals, outer minute track, outermost fifths of a second chronograph divisions, red painted Arabic five seconds numerals, subsidiary seconds dial and 30-minute register with red numerals. Gold spade hands. M. Cal. 19.73N, 19””, frosted gilt, 21 jewels, straight line lever escapement, monometallic balance, selfcompensating Breguet balance spring, cam micrometer regulator, visible split-seconds mechanism. Dial, case, cuvette and movement signed. Diam. 52 mm. The Longines Chronographe Rattrapante is rare in a gold case.