Fabrique d'Ebauches de Sonceboz
The Fabrique d'Horlogerie de Sonceboz was founded in 1845 in Sonceboz in the Vallon de Saint-Imier in Switzerland, making it one of the earliest ebauche factories. Originally known as Rosselet & Challandes, it would become a part of Fabriques d'Ebauches Bernoises in 1927 and would join Ebauches SA later that year.
Rosselet et Challandes
The ebauche firm of Rosselet et Challandes is listed in Sonceboz starting in 1860 but the origins are not entirely clear. An 1879 article places its founding at 1845, but the successor company today claims founding in 1849.
The company is listed as Rosselet & Cie. in 1879 and Fabrique d'Ebauches Paul Robert-Rosselet in 1883. In 1886 it is simply called Fabrique d'Ebauches de Sonceboz. In 1894 the company added "appareilles electriques" to their offerings. The factory was using both hyrdaulic and electric power by 1900.
Fritz-Edouard Pfister was appointed director of the factory in 1906. Pfister's brothers were Henri, director of the Terrasse Watch Company in Le Locle and Alfred, technical director for Longines. Fritz-Edouard Pfister's interests focused on industrial counters, including numeric totalizers for electric discs and roller counters. He used clock movements as reference timers for the switches used to activate urban gas-powered street lighting, with a customer selling 60,000 of these to the city of London in the 1920s.
The Sonceboz factory was greatly affected by the Great Depression and joined Hora in Cortébert and Aurore of Villeret on June 7, 1927 to become Fabriques d’Ebauches Bernoises SA. This group joined Ebauches SA later that year.
Société Industrielle de Sonceboz
Fritz-Edouard Pfister purchased the industrial counter operation, and the Sonceboz factory, from Ebauches SA in 1936. The new company, Société Industrielle de Sonceboz, was operated with his son, Pierre Pfister, who took over after his father's death on June 22, 1946. The company remains in operation in the same factory complex as of 2022.