Vintage Patek Philippe Moon Phase Chronograph Watch Ref. 1518
Silvered dial with applied white gold Arabic numerals, outer 1/5 seconds division and black tachymeter scale, white gold feuille hands. Three subsidiary dials indicating constant seconds and 30 minutes register combined with phases of the moon, two windows for day and the month.
Nickel finished circular movement stamped twice with the Geneva seal, straight-line lever escapement, Cotes de Geneva decoration, self-compensating Breguet overcoil hairspring, bimetallic cut compensation balance and swan neck regulator, cal. 13 “130 Q, 23 jewels. Stamped on the movement of the watches, the Geneva Seal (created in 1886 by Swiss Society of Watchmakers to showcase watches made to the highest possible traditional standards within the canton of Geneva) depicts the coal of arms of the City of Geneva.
This drawing, in the 1948 instruction manual for watchmakers, details the procedures followed when dismantling and assembling a perpetual calendar movement. The calendar requires no manual adjustment and is also programmed for February 29 of a leap year.
The under dial view showing the quadrature for the date, day of the week, month and phases of the moon. The watch with reference 1518 was the world’s first perpetual wristwatch with chronograph made in series. It was launched in the market on 1941.
