1815 Moonphase (Emil Lange) 231.031

The pink-gold 1815 MoonphaseMoon-phase displayAn astronomical indication showing the Moon’s changing appearance through its cycle, averaging about 29.5 days. Display accuracy and the interval between corrections depend on the mechanism; a maker’s specification for one calibre should not be applied to every moon-phase watch. commemorates Emil Lange’s 150th birthday. Reference 231.031 has a black dial with a moon-phase displayMoon-phase displayAn astronomical indication showing the Moon’s changing appearance through its cycle, averaging about 29.5 days. Display accuracy and the interval between corrections depend on the mechanism; a maker’s specification for one calibre should not be applied to every moon-phase watch. among stars at eight o’clock and a subsidiary seconds register. Sotheby’s identifies this pink-gold reference; Lange records a 250-watch pink-gold edition made in 1999–2000.