Swiss large competition observatory chronometer Circa 1933

Heavy deck watch in a wooden case by Longines
–
An exceptional, heavy Swiss competition observatory chronometer in a wooden transport case, circa 1933. This watch features a steel case with factory glazing and a test housing made of wood. It has a silver-plated dial with Arabic radial hours, an outer minutes track, a subsidiary dial for the seconds, and Breguet-style hands. The watch also has a split 3/4 plate movement (65 mm diameter) and a large (24 mm) Guillaume screw compensation balance. Additionally, it comes with a copy of the NPL Cert. (National Physical Laboratory) Class A Kew certificate dated 15.12.1933.
–
Dimensions box: 97 x 55 x 100 mm
–
Diameter: 65 mm
–
Weight: 517 g
–
Signed: Longines
–
With only 12 examples ever made, the observatory calibre was specially crafted for observatory competitions. In addition to its impressive size of 65 mm, the most remarkable feature of this movement is the exquisitely finished escapement section, designed as a removable assembly. This concept offers improved precision regulation handling and component interchangeability. Of the 12 prototypes, 11 participated multiple times in the “A” class competitions, Chronometre de Bord, at the observatory in Geneva and the National Physical Laboratory in Kew. Our No. 300 underwent testing at Kew in 1932 and 1933, achieving high scores both times, with the 1933 result earning 95.60 points and securing the 13th position.