Swiss eight day lever with calendar and moon phases Circa 1970

Gold and enamel eight day going keyless lever 
–
A fine and rare Swiss 18 carat gold and enamel open faced eight day going keyless lever pocket watch with calendar and moon phases, circa 1970. Retailed by Claude Meylan in Vallee de Joux, Switzerland. The gilt brass movement with an inverted patented Hebdomas caliber, an extra large mainspring barrel on the back, a straight line lever escapement, monometallic balance and flat balance spring. Brushed gold eccentric dial with radial applied gold baton indexes and Roman quarter hour numerals, outer dot minute divisions, polished subsidiary dials for the date and days of the week, a fan form aperture for the moon phases, visible balance and original gold hands. Correctors on the polished band, the case back decorated with translucent Royal blue guilloché enamel and a gold paillon rosette, the bezel and pendant are decorated to match. Dial and movement signed 8 Jours Hebdomas Swiss.
–
Diameter: 51 mm
–
Signed: CM Claude Meylan Vallee de Joux
–
The name Hebdomas is derived from the Ancient Greek word for week/the seventh day. It refers to the watch’s ability to run for at least a week on a single winding.

A Hebdomas pocket watch is a timepiece known for its eight day, hand wound movement, off center time indication and a visible balance wheel mounted to a dial side bridge, a feature that makes Hebdomas watches instantly recognizable, and is typically gilded and engraved with a decorative floral motif. A massive mainspring barrel covers the entire diameter of the movement, rotating around the center similar to an automatic rotor.

Most Hebdomas watches feature the name centered in the dial and 8 Jours engraved on either side of the balance. Mostly also featuring a flower or arrow design above.