Extremely rare Longines Siderographe
Reference: siderographe made for the Marine Nationale Aeronavale.
Material: aluminium case
Caliber: 21.29, doble split-chronograph, antimagnetic.
Size: diameter 124mm
Remarks: this marine chronometer was used for astronavigation (at night by the stars) with a double split chronograph, degree indication and 30 hours power reserve indicator. Three tone silvered dial with color code scales that matches the hands indications (degrees and minutes of arc). Mounted in wooden glazed box. In excellent condition.