The latest creation from A. Lange & Söhne combines three complications and five additional functions. In this regard, it should be emphasised that the greatest challenge in developing a watch with multiple complications lies in the perfect interplay of the various complex mechanisms in a harmonious design. Its black dial in solid silver contrasts aesthetically with the 41.5 millimetre diameter platinum case and the hands and indices made of rhodium-plated gold. This fine watch is also produced in a limited series of 100 pieces. The name Datograph identifies a chronograph with a column wheel, precise jumping minute counter, flyback function and Lange's iconic large double date window. In order to be able to perform short and precise timekeeping, the designers resorted to the construction of the Datograph Up/Down, which brings together three major technical achievements of chronograph construction in a single watch: the column wheel, which guarantees reliable adjustment of all chronograph functions, the 'jumping minute' counter, which precisely indicates the time measured, and finally the flyback mechanism, which allows time measurements in rapid succession with extremely short reaction times. The name Perpetuo, for its part, refers to the perpetual calendar 'jumping exactly', with an indication of the phases of the moon. All indications of the perpetual calendar, which, in addition to the date, also include indications of the day of the week, the month and the leap year in the auxiliary dials, advance by jumping exactly and are therefore always perfectly legible. The mechanism only needs to be advanced by one day on 1 March of the secular year 2100. Moreover, thanks to the high degree of mechanical precision, the moon phase display only deviates by one day from the actual lunation cycle after 122.6 years. Three correction pushers allow separate adjustment of the moon phase display, the day of the week and the combined advancement of the month and leap year display. If the watch has been stopped for a few days, all the calendar indications can easily be advanced together by means of the rapid correction button. Added to this is the fascinating mechanism of the tourbillon, which offers itself to the eye through the sapphire glass back and the open bridge on the tourbillon itself. Here, inside the filigree cage, the entire escapement rotates once a minute around its axis. This rotary motion compensates for the negative influence of gravity on the eccentric balance. The manufactory-made free-floating balance spring ensures excellent rate stability throughout the entire 50-hour power reserve. An integrated power-reserve indicator at the end of the tachymeter scale reminds one of the timely winding of the watch. The balance oscillates for the first time in a Lange tourbillon at 18 000 instead of the usual 21 600 vibrations per hour. This choice was necessary in order to be able to display the timed time to exactly one-fifth of a second. When the crown is pulled out, the patented seconds stop mechanism instantly locks the balance inside the tourbillon cage. However, not only the development, but also the finishing and assembly of the calibre L952.2, comprising 729 components, pose great challenges for the Lange Manufacture. Only the most talented watchmakers manage to overcome the countless obstacles to the flawless interplay of the various mechanisms. This requires a great deal of experience, virtuosity, concentration and patience. Thus, even in the Datograph Perpetuo Tourbillon, one can appreciate the great aptitude of the German watchmaker in continuing to evolve and always pushing the limits of mechanical watchmaking.
