A. Lange & Sohne Richard Lange Perpetual Calendar Terraluna

Just launched for SIHH, the Richard Lange Perpetual Calendar Terraluna from A. Lange & Sohne has caught the attention of many aficionados around the world. In many ways this masterpiece shows why this amazing watch manufacturer is a step ahead of many of its competitors. This timepiece is quite possibly the most complicated watch to come out of SIHH 2014.

The Richard Lange Perpetual Calendar Terraluna comes in a large size of 45.5mm and can be purchased in either 18kt white or rose gold. The gold in both models is polished to a fine finish. The main crown is ridged allowing for the easy winding and adjustments of the perpetual calendar. There is a push piece at the 2 o’clock position is also used as a corrector for the perpetual calendar function. The case back is exhibition styled being made from transparent sapphire crystal and it reveals the L096.1 manual wound movement. The Richard Lange Perpetual Calendar Terraluna is fitted with a brown or black alligator leather strap depending on which metal variation is chosen.

The movement is where one can find the Terraluna aspect of the watch. The Terraluna feature actually makes up more than 80% of the ¾ main plate. This function is a very unique orbital moonphase display. Not only does this complication indicate the moon phase but it also indicates the position of the moon relative to the earth. The lunar disc will make one complete revolution around the depiction of the earth once every month. There are a total of three discs in rotation – the moon, the earth, and the stars.

The movement also features a Constant Force Mechanism, which makes the escapement transfer energy to the twin barrels in 10 second intervals. Anything more and there would have been too much torque in the balance spring.

The dial is laid out as a Regulator with the most prominent dial indicating the minutes. This dial also carries A. Lange & Sohne’s signature large double date aperture. The hour dial and seconds dial can be found at the 4 and 8 positions respectively. The hour dial encompasses the month aperture, while the seconds dial features the day aperture. At the 6 position is a very detailed power reserve indicator, which counts down the 14 days of power available to the Richard Lange Perpetual Calendar Terraluna watch when fully wound. There is a very subtle leap year indicator at the 2:30 position.