A Lange & Sohne Tourbograph Pour le Merite Watches

In many areas of luxury the end consumer is often met with the finished product with little idea of how that product was actually developed the way it was, nor why. Here A. Lange & Sohne provides a fascinating insight into how it approached three technical areas of watch*** and reveal how each of those paths evolved.The first of Lange's innovations for 2010 is harder gold (top). Chemically speaking, this novel "honey-coloured" gold is an 18-carat gold alloy which means it consists of 75 percent pure gold. Its colour lies midway between pink and white gold and is attribut-able to its copper and zinc content.The combination of a special thermal treatment with a slight admixture of man-ganese is responsible for its extraordi-nary hardness which registers between 300-320 HV on the Vickers scale. To put that in perspective, yellow gold's value lies between 135-150 HV meaning honey-coloured gold is more than twice as hard. The benefits to the watchmaker and the wearer are obvious, offering far improved scratch resistance and durability.Meanwhile another of Lange's discoveries for 2010 centres round its Zeitwerk timepiece (above) which boasts numerals that are obscured behind the dial for most of the day. To ensure the wearer can read the time in the dead of night, the numerals’ ability to absorb light had to be addressed.Lange's solution was to create a sapphire-crystal dial with a semi-transparent but UV-permeable coating. The light in the ultra-violet (UV) range from 250 to 430 nanometres is allowed to pass unhindered so the Superluminova numerals can be charged up with photonic energy even when obscured behind the dial. This allows them to glow for several hours at night despite not seeing sunlight in the traditional sense for much of the day.The final innovation likewise involves luminosity but is related to lunar discs rather than numerals. Lange's 1815 Moonphase is accurate to such a degree that it takes over a thousand years for the display to be off by one day relative to the moon's position. Maintaining this excellence, Lange wanted to develop a coating for the stars that would genuinely emulate the appearance of the night sky.The brand employed a group of scientists who pioneered a new process in the watch*** industry in which they apply extremely hard carbon films to the solid-gold lunar discs through physical vapour deposition �C known as PVD. This adjustment of the su***ce not only delivers the desired col-our hue but also very high wear resistance. The lunar discs are crisp and brilliant.

A. Lange & Shne is celebrating Wempes 150th anniversary with the 1815 Side Step, a mechanical watch with a 45-hour power reserve. This model, with case and crown in pink gold or platinum and a sapphire crystal, is water resistant to 25 meters. The strap is black crocodile for the platinum models, brown crocodile for the pink-gold ones.4/7/03