With Patek Philippe Extract from the Archives confirming production of the movement of the present watch in 1925. It was completed and encased in 1929 and sold on 16 January 1930. The Extract further states that the watch obtained a Geneva Observatory rating certificate in 1929/1930. Also delivered with copies of the Geneva Observatory timing sheet and results of the 1929 First Class timing contest where the watch obtained an Honorable Mention with 623 points. It had been prepared and adjusted by the renowned adjuster F. Modoux.
Patek Philippe chronometer movements were made to the highest possible standards and specially adjusted by master adjusters such as the celebrated F. Modoux, Henri Wehrli, J. Golay-Audemars and C. Batifolier. Watches prepared by them, especially those awarded prizes at the Observatory Contests, were several times more expensive than the standard versions.
The present watch is exceptionally well made, adjusted for the Observatory Contest, and engraved on the pillar plate and bridge with the serial number, which was one of the prerequisites of the Observatory Contest rules. A variety of details including the Guillaume balance with small "wings" at the arm for poising "in the raw", e.g. before the screws were fitted hence assuring that the temperature compensation adjustment would not affect poising, the superior polish of the steel parts, the olive-shaped jewel holes and the very light undercut escape wheel with raised teeth, prove the highest quality of this particularly fine watch. The unusual signature "Chronomètre" followed by the movement number in the power reserve indicator further underline this fact.
Precision timekeeping has always been vital to the scientific community, and in 1873, the first annual chronometer competition was held at the Geneva Astronomical Observatory. Rigorous quantitative internationally recognized testing standards were established. The testing, which initially lasted 40 days, consisted of placing the watches in various positions and temperature conditions. The prestigious watchmakers Patek Philippe were awarded First Prize in the competition as early as 1884.