A. Lange & Söhne Richard Lange Perpetual Calendar Terraluna
by Guillaume V - 09/10/2014
The three, pyramid-shaped rings on the dial of the regulating mechanism of the A. Lange & Söhne Richard Lange Quantième Perpétuel “Terraluna” remind instantly of an historical timepiece : the gold n°93 pocket watch from the prominent Saxon watchmaker Johann Heinrich Seyffert.
Now, the three rings on the dial correspond to three, separate displays for each time unit: minutes at the top, hours and seconds at the bottom. The jumping displays of the perpetual calendar are perfectly integrated into the dial, like the power reserve indicator and the first big Lange date in a model from the Richard Lange family.
As for the case back : the movement is just as spectacular with its patented orbital display of the moon phases which follows the position of the moon according to that of the Earth and the sun. This display, made up of 3 solid gold disks, matches the lunar month (29 days, 12 hours, 44 minutes et 3 seconds) so precisely that a one-day correction will only be necessary in 1,058 years.
The mechanical part is also impressive : its perpetual calendar not only takes into account the various duration of the months of the calendar year, but also leap years until 2100. To limit the force required for the commutation process, the necessary energy is continuously accumulated and released in one go at midnight.
The double-barrel and the constant-force escapement of the L096.1 caliber allow the Richard Lange Quantième Perpétuel “Terraluna” to offer a 14-day power reserve with variable amplitude and great working regularity from the first day to the last.
In addition, the balance wheel spiral but also the intermediary mainspring of the constant-force escapement are manufactured internally.
With an impressive mechanical part, the Richard Lange Quantième Perpétuel “Terraluna” also features an amazing pink or grey gold, 45.5 mm diameter case.
A. Lange & Söhne Richard Lange Perpetual Calendar Terraluna, Pink Gold
A. Lange & Söhne Richard Lange Perpetual Calendar Terraluna, white gold