Glossary  A - B   C - F   G - L   M - P   Q – S   T - W

Quartz   Timekeeping's technical revolution found its way to the world's wrists in the late 1960s. This was a principally Swiss invention – the first working quartz wristwatches were manufactured by Girard-Perregaux and Piaget as the result of an early joint venture within the Swiss watch industry, but Japanese firms, primarily Seiko, came to dominate the market with new technology. The quartz movement uses the famously stable vibration frequency of a quartz crystal subjected to electronic tension (usually 32,868 Hz) as its norm. The fact that a quartz-controlled second hand jumps to the beat of each second is a concession to the use of outside energy.     Retrograde display   A retrograde display shows the time linearly instead of circularly. The hand continues along an arc until it reaches the end of its scale, at which precise moment it jumps back to the beginning instantaneously. This Nienaber model not only shows the minutes in retrograde form, it is also a regulator display.     Rotor   The rotor is the component that keeps an automatic watch wound. The kinetic motion of this part, which contains a heavy metal weight around its outer edge, winds the mainspring. It can either wind unilaterally or bilaterally (to one or both sides) depending on the caliber. The rotor from this Temption timepiece belongs to an ETA Valjoux 7750.     Sapphire crystal   Synthetic sapphire crystal has become the material of choice to protect the dials of modern wristwatches. This material, known to gemologists as aluminum oxide (AI2O3) or corundum, can be colorless (corundum), red (ruby), blue (sapphire), or green (emerald). It is virtually scratchproof with a hardness of 10 on the Mohs scale; only a diamond is harder. Corundum is «grown» using a method invented by Auguste Victore Louis Verneuil in 1902 whereby a process that usually takes a hundred thousand years to complete is accelerated to just a few hours, hence the use of the term synthetic. The innovative Royal Blue Tourbillon by Ulysse Nardin pictured here not only features sapphire crystals on the front and back of the watch, but also actual plates made of both colorless and blue corundum within the movement.     Screw balance   Before the invention of the perfectly weighted balance using a smooth ring, balances were fitted with weighted screws to get the exact impetus desired. Today a screw balance is a subtle sign of quality in a movement due to its costly construction and assembly utilizing minuscule weighted screws.     Seal of Geneva   Since 1886 the official seal of this canton has been awarded to Genevan watch manufactures who must follow a defined set of high-quality criteria that include the following: polished jewel bed drillings, jewels with olive drillings, polished winding wheels, quality balances and balance springs, steel levers and springs with beveling of 45 degrees and côtes de Genève decoration, and polished stems and pinions. This list is not exhaustive, but presents a clear idea of the precise elements needed for a movement to receive the soughtafter seal. The pictured seal was awarded to Vacheron Constantin, a traditional Genevan manufacture.     Skeletonization   The technique of cutting a movement's components down to their weight-bearing basic substance. This is generally done by hand in painstaking hours of microscopic work with a mini handheld saw, though machines can skeletonize parts to a certain degree, such as the version of the Valjoux 7750 that was created for Chronoswiss's Opus and Pathos models. This tourbillon by Christophe Schaffo is additionally – and masterfully – hand-engraved.     Sonnerie   A variety of minute repeater that – like a tower clock – sounds the time not at the will of the wearer, but rather automatically (en passant) every hour (petite sonnerie) or quarter hour (grande sonnerie). Gérald Genta built the most complicated sonnerie back in the early nineties. Shown is the latest evolution of that model from the front and back.     Split-seconds chronograph   Also known in the watch industry by its French name, the rattrapante. A watch with two second hands, one of which can be blocked with a special dial train lever to indicate an intermediate time while the other continues to run. When released, the split-seconds hand jumps ahead to the position of the other second hand. The PTC by Porsche Design illustrates nicely that there are two second hands for the chronograph present on the dial, one red and one white. The exploded illustration shows a rattrapante module.     Spring barrel   The spring barrel contains the mainspring. It turns freely on an arbor, pulled along by the toothed wheel generally doubling as its lid. This wheel interacts with the first pinion of the movement's gear train. Some movements contain two or more spring barrels for added power reserve.     Swan-neck fine adjustment   A regulating instrument used by the watchmaker to adjust the movement's rate in place of an index and located on top of the balance cock. The swan neck is especially prevalent in fine Swiss and Glashütte watchmaking. Glashütte Original has even invented a duplex version of the swan neck, and Mühle Glashütte has varied the theme with its woodpecker's neck. The swan neck shown here comes from Lang & Heyne's Moritz model.

Courtesy of Wristwatch Annual 2006 © Abbeville Press  A - B   C - F   G - L   M - P   Q – S   T - W