Paul Perret

Paul Perret (1854-1904) was a watchmaker and regulator famous for promoting Invar, the material invented by Charles-Edouard Guillaume, for use in balances and hairsprings. He died just as his spring factory was getting started and it was sold to the FSR cartel. In 2014, a watch brand was created to celebrate Perret, but this failed as of 2022.

Biography

Paul Perret was born in in La Sagne in 1854. He was a member of the commission of the watchmaking school in La Chaux-de-Fonds or Fleurier in 1877 and 1878 and held the rank of major in the army.

Perret spent his working life in La Chaux-de-Fonds and was known as a skilled adjuster of chronometers. In the 1880s, Perret became well-known for two adjustment instruments of his invention: the "campyloscope", to check the terminal curve of a hairspring against a large-scale drawing; and the "talantoscope", to compare the oscillation of a test balance with that of a standard balance.

The campyloscope was recognized by the jury at the Universal Exhibition in Paris of 1878.

By 1883, Perret's eponymous company, located at Rue du Parc 65 in La Chaux-de-Fonds, was advertising in Indicateur Davoine. The firm offered adjustment machines, served as an adjustment workshop, and specialized in carefully adjusted balance wheels and springs. The company also boasted of winning a 1st class prize at La Chaux-de-Fonds in 1881, two silver medals in 1879 and 1881, a medal in Paris in 1878, and an "Invention and Fine Execution Diploma" in Geneva in 1880. Perret closed this firm in 1895.

In 1894, Perret joined with Louis-Emile Perret and Charles-Fréderic Perret to found Perret Frères, a maker of mainsprings for watches. The firm was located at Rue du Doubs 157 in La Chaux-de-Fonds.

On learning of the invention of a nickel-steel alloy by Charles-Edouard Guillaume in March 1897, Perret requested a sample. He was the first to experiment with a nickel-steel balance spring, bringing a sample to Guillaume in Sèvres to show the remarkable accuracy he had achieved. Working together, Guillaume and Perret developed an alloy that showed zero variation between zero and 30º C in observations on August 20, 1897. This material would later be known as Invar, and Guillaume opted to work with Perret to commercialize it. Paul-David Nardin and Paul Ditisheim were also granted early access to Guillaume's nickel steel but they focused on the balance wheel rather than the spring. The production of Invar balance wheels was licensed to FSR and produced by Ferrier & Vaucher in Travers.

On August 1, 1901, Perret set up a workshop in Fleurier to produce Invar balance springs but had only gotten started when he was struck ill. The firm was located at Rue de l'Ecole d'Horlogerie and was entirely focused on nickel-steel springs. The company had a troubled start, declaring bankruptcy on May 16, 1902 before being re-formed as a Société Anonyme on December 23 of that year. This new company was operated by Albert Welter of Fleurier, with Perret himself serving as technical director. It was located on Avenue Daniel Jean-Richard in Fleurier.

Although Invar balance springs were remarkably stable, they were difficult to work with. The material was too soft, so crafting an acceptable spring required a great deal of skill and experience, and they were easily damaged. Guillaume later developed a superior material for springs, which was introduced in 1919 and called Elinvar. Another issue for Invar springs and balances was the difficulty in producing the exact alloy in volume. The French forges at Imphy were the only source, resulting in issues once that nation was at war.

Perret died in Le Landeron on March 31, 1904 at 49 years of age. He was survived by his widow and daughter.

His assets were to be liquidated on May 14, but it was instead acquired. The firm was modified on August 25, 1904, following Perret's death. Henri Wittwer became director along with Fleurier merchant Edouard Ledermann. Albert Welter temporarily became manager. The company's address was listed as Rue de l'Ecole d'Horlogerie 7 in Fleurier. Finally, SA des Spiraux Paul Perret was liquidated on September 12, 1906. All of the company's trademarks and patents were transferred to FSR in late 1906 and early 1907. Reports suggest that it was Paul Baehni who was responsible for the purchase by FSR, and he transferred production to his family workshop in Bienne as well as the new FSR factory in Geneva.

FSR advertised "Spiraux Compensateurs Paul Perret" as early as 1903, but this was taken instead by Fabrique Nationale des Spiraux from 1904 through 1907 before reverting.