dorothea lange i am an american

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.

With the introduction of the Lange Zeitwerk timepiece, the celebrated watchmaking house of A. Lange & Sohne ventures confidently into the realm of contemporary time displays. This brilliant example of Saxon haute horlogerie presents outsized jumping digital displays for the minutes as well as the hours, in addition to a conventional power reserve indicator and subsidiary seconds with a stop function. Naturally, this visually dramatic masterpiece is animated by a complex and perfectly crafted mechanical movement conceived and produced by A. Lange & Sohne.The A. Lange & Sohne Zeitwerk watch is available in 18K pink, yellow or white gold, as well as platinum. In all of these noble materials, the stately case measures 41.9 millimeters in diameter, and 12.6mm tall. Impeccable in its luxurious detail, the case displays brushed finishing on its central section, and a rich polish on such sections as the strap lugs and bezel. The solid silver dial is characterized by a “time bridge” central section in contrasting German silver, which elegantly unifies the digital hours, digital minutes, and traditional subsidiary seconds. The symmetric arrangement is completed perfectly by the semi-circular power reserve scale at 12 o’clock which sweeps gradually to and fro to indicate the degree of tension remaining in the spring barrel.Comprised of 388 hand-finished parts, the 66-jewel Lange Calibre L043.1 carries on the fabled reputation of A. Lange & Sohne for manufacturing movements of the highest aesthetic and technical distinction. The caliber features the signature elements of a three-quarter plate in untreated German silver with Glashutte ribbing, a hand-engraved balance cock, and certain movement jewels (two, in this instance) set in screwed gold chatons. Like the acclaimed Richard Lange model, the Zeitwerk’s movement features the in-house Lange balance spring attached with a patented balance clamp; a precise beat adjustment device with a lateral setscrew and whiplash spring allows the watchmaker exceptional latitude for fine-tuning. Balance frequency is a traditional 18,000 vibrations per hour, and power reserve is 36 hours at full wind. A sapphire crystal exhibition window in the screw-secured caseback allows an expansive view of this watchmaking exemplar. Considerable ingenuity was required to solve the technical difficulties imposed by the energy-hungry disc switching operation. A specially-engineered barrel with an extra-strength mainspring ensures an optimal amount of torque to animate the watch and its battery of jumping discs. Assisting in regulating the considerable forces of acceleration and stopping that the discs undergo as they instantaneously switch is a rotating fly governor–its vanes displace air and are thus able to channel excess energy and produce a gentle impulse for the switch sequence. A remarkably compact constant force escapement positioned between the barrel wheel and the balance keeps energy flow to the balance consistent across the power reserve range, even with the hour and minute jumps taken into account. The A. Lange & Sohne Zeitwerk watch features a curved sapphire crystal, and hand-sewn straps in crocodile leather with a massive Lange buckle in 18-karat gold, or platinum. The solid silver dials are rendered in different finishes, according to the metal of the case: champagne for yellow gold, argente for pink gold, black for white gold, and rhodium-plated for platinum.