This is a very unusual tourbillon. Exceptionally well finished, it has all the features of a superior timekeeper from the period: superbly finished tourbillon carriage, superior chronometer escapement, free-sprung helical balance spring, reversed fusee to equalize the torque on the escapement without excessive wear on the center wheel bushing (not to be confused with inverse fusee). The finish is superior, including even the smallest details, such as the double click on the ratchet wheel, or the Maltese cross on the fusee, the use of gold for the wheel train, and nickel not only for the plates but also for the fusee and the barrel, the jeweled barrel, the skeletonized fusee/barrel bridge, and the recessed balance arm. All these elements clearly point to an exhibition piece. Another unusual feature of the chronometer is its carriage, which is found in very few early Swiss watches and in Adolph Lange's watches. The Lange carriage was designed by Fridolin Stübner circa 1870. One watch with this type of carriage, made circa 1870 by Girard Perregaux and formerly in the Paul M. Chamberlain Collection, is known to exist. A similar unsigned watch dating from the same period was sold by Antiquorum on October 3, 1976, lot 189. There are only two Swiss tourbillon watches from the period known with winding indicator, the above-mentioned Gerard-Perregaux and the present watch. During the 1860s and 1870s very few makers in Switzerland were capable of making a tourbillon. They were Ernest Guinand, Auguste Grether, and Roulet from Pont-de-Martel. The present watch is extremely important in the history of Swiss tourbillon production, it is also interesting in that it demonstrates the tremendous effort which went into producing an object for a Universal Exhibition. The 1876 Universal Centennial Exhibition in Philadelphia was a pivotal event in watchmaking history. During the Exhibition, American watchmakers demonstrated that excellent watches could be made with the aid of machines. After returning from the exhibition, where he was a judge as well as the Swiss Delegate to the Exhibition, Edouard Favre-Perret made a report. This report, delivered on November 14, 1876 in La Chaux-de-Fonds to the Swiss watch industry, changed the way the Swiss perceived watch production. Favre-Perret said ?For a long time America has been the principal market for our watches ? our milk cow, so to speak. Today we must earnestly prepare to struggle with the Americans on the fields where we have been the masters?. Having said this, the Swiss contingent of 54 exhibitors received a total of 41 medals which represented 76% of the medals awarded in the watchmaking category. The present watch thus demonstrated the skills of Swiss watchmakers at this turning point in watchmaking history. In several favre-parrets reports He states that this watch was the only exeample of a watch with tourbillon to be found in Phladelphia. If the Swiss were impressed by the Americans, the latter must have been equally impressed by the former when examining this watch.