In a typical tourbillon the carriage is mounted on the 4th wheel pinion, which holds the seconds hand. Concentrically to it, a raised stationary wheel is fixed to the pillar plate. The escape wheel is mounted in the carriage in such a way that it gears with this stationary wheel and "runs" around it bringing with it the entire carriage since, usually the 4th wheel rotates once per minute. Such tourbillons are called one-minute tourbillons. Although there exist some variation to this design, they are, as a rule, rare. The one in the present watch is exceptionally interesting. The watch has an extra large wheel driven from the fourth wheel the one with the seconds hand fixed to it. This is the base for the carriage with thick 1.1 mm. hollow pivots, of which the bottom one runs in a large jewel in the plate and the top one in a similar jewel in a top bridge. Concentrically to the carriage in the pillar plate is fixed a raised sta ionary wheel as in a regular tourbillon which gears with the escape wheel mounted in the carriage. This gave the designers an opportunity to plant the balance independently of the carriage, directly on the movement through the hollow pivots. This allows better balance stability as well as better control of the oil flow to the balance staff pivots. The finish of the watch is exceptional; the steel parts are either matte with highly polished edges or polished throughout. For the jewels transparent sapphires were chosen, the regulator was fitted with adjustable pins to increase the isochronism. The train is designed for the smoothest transmission with pinions having a high number of leaves center wheel 96/12, 3rd wheel 90/12, 4th wheel 70/12, carriage 120, fixed wheel 120, escape wheel 15/7 giving the carriage rotation 1 and 5/7 minute, ap roximately 1 minute and 42 seconds, and setting the beat for 18,000 per hour. The escape wheel is recessed with beveled teeth to decrease the impulse friction, and lastly, a large Guillaume balance was employed. Georges Sautebin 1890 - 1974 Was director of adjustment at the Horological School at La Chaux-de-Fonds. During his career he obtained 28 prizes at different Observatory Timing Contests, spanning from 1923 to 1958. In 1932 he patented an improved way of mounting endstones Swiss patent o. 153880. The Musée International d'Horlogerie in La Chaux-de-Fonds has in its collection a one-minute tourbillon made by Sautebin, based on "Pellaton" caliber. Anibal Acier au Ickel pour BALanciers, An alloy invented by Dr. Charles Edouard Guillaume, exhibits unusual properties, both in terms of thermal expansion and in changes in elasticity. These properties are very different from those of two other famous alloys invented by Guillaume, Invar and Elinvar. Around 1900 Guillaume attempted to eliminate the so-called Middle Temperature Error caused by the fact that the change of rate in a timekeeper with a steel-brass bimetallic balance is approximately a linear function of temperature, while he change of rate caused by change in elasticity of a balance spring is approximately a quadratic function. Thus, it equals zero at only two temperatures, causing secondary error. Countless attempts were made to eliminate Middle Temperature Error, usually by means of auxiliary compensation devices. In 1899, Guillaume noticed that steel with an addition of 44.4% nickel had a negative square coefficient of thermal expansion. This alloy, combined with brass in bimetallic lamina, makes its expansion close to quadratic. Balances with bimetallic rims made of anibal and brass are usually called Guillaume bal nces, or, as their inventor called them, integral balances. When combined with special balance springs, they exhibit remarkable temperature stability, on occasion not exceeding 1/50 second per day at 1oC. In our April 2003 sale we offered the smallest tourbillon in the world, lot 559. It was made by Fritz-André Robert-Charrue, with a diameter of 19,7 mm. Antiquorum is pleased to present today the world's largest prize-winning deck tourbillon, with a diameter of 65 mm.