The present watch is fitted with Ditisheim so-called "calibre type 3", a slim movement with LeCoultre ébauche, featuring his patented compensation balance with outer bimetallic affixes, Swiss patent no. 98234 obtained in 1920. For a description and illustration of this balance see Paul Ditisheim Chronometers by Fritz von Osterhausen, pp. 24 - 26.
Paul Ditisheim (1868-1945), considered a genius in the world of horology. At the early age of 13 he entered the Horological School in La Chaux-de-Fonds where he obtained the Diploma of Honour. Before founding his own company in 1892 he worked for several renowned watch manufactures such as his father's, Vulcain, Ditisheim Frères. Around 1920, he entered into partnership with Solvil.
Paul Ditisheim is renowned for his highly precise chronometers for which he won an impressive number of prizes at various Observatory Contests. He also played an important role during the launch of Dr. Charles Guillaume's compensation balance, invented at the end of the 19th century and used in several of his watches during the Grand Prix in Paris in 1900.
Paul Chamberlain states in It's about Time, 1978, pp.463-7:
....M. Paul Ditisheim excelled in every form of watchmaking. He made the smallest watch in the world for the Sultan of Morocco, he designed and executed timepieces of great precision, and exhibited enviable talent as a regleur of his own pieces. He collaborated with Dr. Guillaume in the application of Invar and Elinvar, and produced by their own use and to his own invention of an 'affix', or very small bimetal compensation to the solid balance, a movement which made new records at most of the observatories of the world. A silver cased nineteen jewel, 'up and down' indicator watch, costing sixteen dollars at the factory, sent by me to the Bureau of Standards, took a First Grade Certificate'.