Louis Rozat
Louis Rozat was a watchmaker active in La Chaux-de-Fonds from at least 1875 through 1910. Rozat produced an 8-day watch called Octomères as well as complicated watches, chronometers, and ladies watches. Additionally, Rozat produced a brand of specialty oil for watchmakers branded "Sine Dolo".
Louis Rozat was born in 1850 in Chateau d'Oex in Canton Vaud and died in 1911. He attended the school of watchmaking in La Chaux-de-Fonds from 1866 to 1870 and was remembered as one of the best students there. From 1877 through 1900 Rozat served on the board of the school, including as secretary. Rozat also served on the Société des Fabricants d'horlogerie de La Chaux-de-Fonds, acting as secretary starting in 1915.
Advertisements for L. Rozat around 1900 show "Maison fondée en 1830" though it is unclear if this was Louis Rozat's father or grandfather. Rozat was definitely active as a watchmaker by the 1870s as he won a medal in Paris in 1878 and is listed in Indicateur Davoine in 1875. He also won medals in La Chaux-de-Fonds in 1881, Zurich in 1883, Paris in 1889, and Chicago in 1893 and was a member of the jury in Geneva in 1896.
Rozat's workshop at Rue St-Pierre 22 in La Chaux-de-Fonds is noted in the 1883 business survey. In 1895 he opened a maker of watch hands at Rue du Parch 47, though he exited this business in 1898. He began selling a specialty oil for watchmakers branded "Sine Dolo" by the 1890s.
It appears that Rozat specialized in watches for the English market, producing quality anchor and cylinder watches with 3/4 plate English style movements from 13 to 20 lignes. Rozat also advertised complicated watches and chronometers, winning chronometer tests around the turn of the century.
One of Rozat's most lauded accomplishments was adjusting his Octomères 8-day watch to perform acceptably through the entire power reserve. A 1901 article in Journal Suisse d'Horlogerie praises "the consistency of said adjustment – this stumbling block of the genre – is guaranteed by the house." It also mentions that Rozat produced "a split-seconds chronograph counter, as well as several ladies' watches, always in very careful quality."
Rozat handed his business to his son, Louis Rosat (note the spelling change) on October 15, 1910. The younger Rosat was located at Rue Numa Droz 71. The company moved to Rue de la Balance 10 in 1916 as Louis junior re-focused on the Sine Dolo oil.
On his death on December 10, 1910, the Journal notes that Rozat "was a very zealous member of the inspection commission of the cantonal observatory; he rarely missed a session, and he took a great interest in the development of the chronometric service. Destiny did not grant him the favor of seeing the scientific installations completed to which he attached great importance for the practical services of the observatory."