The movement is engraved “Paul Ditisheim La Chaux-de-Fonds Switzerland / The Highest Records at Kew Teddington and Swiss Observatories”; the inscription refers to the 200- some prizes Paul Ditisheim (1868-1945) won at Kew and in Neuchâtel. He was one of the most esteemed Swiss horologists of the first half of the 20th century. Among Ditisheim deck watches, the ones with this type of movement, sometimes called “type 1”, are the most impressive; they won more Observatory prizes than any others. Solvil was founded in early-1920’s to exploit Ditisheim’s invention, and produce the highest possible timekeepers. The present watch is an excellent example of the early Solvil production. Ditisheim, Paul (1868-1945), La Chaux-de-Fonds, October 28, 1868 ?? Geneva, February 7, 1945 After early training in Switzerland, he studied in Berlin and Paris, arriving in England in 1891, where he worked as a technician at the Rotherham factory in Coventry. He started his own manufacture at La Chaux-de-Fonds in 1892, specialising in very high precision watches and jewelled watches. Success in both spheres followed rapidly, and he won many honours for adjusted watches, especially at the Neuchâtel and Kew Observatories. He designed and patented his own compensation balance (Swiss invention patent No. 98 234), developed a new oil with remarkable stability, and was known for his superior skills in adjusting, skills that won him many prizes and honours. He collaborated with Dr. Ch. E. Guillaume (1861-1938) in the use of both the Guillaume “integral” balance and the Elinvar-type of auto-compensating balance spring. He also contributed many papers to scientific and horological journals, and was associated with Dr. Paul Woog, an oil chemist, in the development of Chronax oils. Guillaume Balance The Guillaume balance is a compensated bimetallic balance, made of anibal (an alloy of steel and nickel) and brass, after the works of Dr Charles-Edouard Guillaume (1861-1938), with which the middle-temperature error is practically eliminated. The middle- temperature error (or Dent’s anomaly), is the difference between the rate of a chronometer at the mean temperature and the average of the rates at extreme temperatures. This type of balance was used by the horological manufactories since 1904. Ditisheim-Solvil deck chronometers - No. 703 446? Antiquorum, Geneva, auction, October 11, 2003, lot 222, sold for the amount of CHF 20 700.- - No. 703 453? Antiquorum, Geneva, auction, March 27, 2011, lot 428, sold for the amount of CHF 22 500.-