Some 3,600 years separate the #richard-lange-perpetual-calendar-terraluna-/introduction/180-026">RICHARD LANGE PERPETUAL CALENDAR "Terraluna" by A. Lange & Söhne and the oldest realistic rendition of the nocturnal sky, the Nebra Sky Disc, but these two share a common objective: To illustrate the progression of celestial bodies as accurately as possible.
Terraluna means blue moon in English, and refers to the second full moon within a given calendar month, a rare phenomenon that on average occurs only every two and half years.
"Once in a blue moon," most mechanical moon-phase indications must be corrected by one day.
This occurs because most watchmakers round the period of time between two new moons down to 29.5 days for simplicity’s sake, even though the cycle is actually 44 m 3 s longer.
But not the RICHARD LANGE PERPETUAL CALENDAR "Terraluna". It is calculated with such accuracy that it takes 1,058 years to deviate by one day.
The patent-pending orbital moon-phase display of the timepiece, showing the constellation of the moon relative to the earth and the sun, is a genuine innovation in the domain of precision watchmaking.
With peerless accuracy, it depicts the changing orbital position of the moon relative to the earth and the sun. It is based on calculations used to determine the orbits and altitudes of planets attributed to Danish astronomer Tycho Brahe (1546 - 1601) whose observations of planetary positions were the most precise ones in the era before the telescope was invented.
On the dial side of the 45.5-millimetre pink- or white-gold case, the watch stands out with the regulator layout of scientific precision watches. The large minute circle is at the top of the dial whilst the smaller dials for the hours and seconds are beneath it, shifted toward the right and left.
The display also accommodates the four precisely-jumping perpetual calendar displays: date, day of week, month and leap year.
Finally, in addition to the balance spring which has been manufactured by A. Lange & Sohne since 2003, the remontoir spring of the constant-force escapement is also made in-house for the new L096.1 manufacture calibre. The indexless oscillator beats with a frequency of 21,600 semi-oscillations per hour.
Further Lange-style quality hallmarks include the hand-engraved balance cock and a lavishly hand-decorated movement — exemplary manifestations of the watchmaker's quest for precision.
A. Lange & Söhne ION Orchard
2 Orchard Turn, #02-05A, Singapore 238801
(65) 6509 9218