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 and talantoscope were recognized by the jury at the Universal Exhibition in Paris of 1878 with a bronze medal.

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.

The talantoscope caused a stir in 1889 when it was suggested in La Fédération Horlogère that the device would eliminate the need for skilled adjusters. When Paul Perret refused to engage with his critics and instead patented the device for production, rumors spread that he intended to sell it in America, undermining the Swiss watch industry. Eventually Perret's supporters, who were responsible for the anonymous letter that caused the controversy, admitted their involvement and Perret himself reassured everyone that his device would be made available in Switzerland.

Perret's skills as an inventor and regulator eclipsed his business sense, however, and he closed his eponymous firm in 1895. In 1894, seeking a more scalable trade, 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.

Perret, Guillaume, and Invar

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.

Paul Perret's Legacy

Paul Perret's assets were to be liquidated on May 14, 1904, but the legal case was delayed when investors came forward to take over. The firm was modified on August 25, 1904, with Henri Wittwer becoming director along with Fleurier merchant Edouard Ledermann. Former director Albert Welter temporarily became manager. The company's address was listed as Rue de l'Ecole d'Horlogerie 7 in Fleurier, likely the same building all along.

FSR advertised "Spiraux Compensateurs Paul Perret" as early as 1903, but it seems that this was taken instead by Fabrique Nationale des Spiraux from 1904 through 1907 before reverting. Working with this dissident spring maker may have been Wittwer and Ledermann's way of pressing FSR for a higher price.

Finally, in the summer of 1906, word leaked that the firm was to be purchased by FSR. This was confirmed in September and the transaction took place on September 12, 1906. All of the company's trademarks and patents were transferred to FSR in late 1906 and early 1907. The cartel immediately set about polishing the reputation of Perret's Invar springs, commissioning a second study of their accuracy in coordination with Dr. Arndt, director of the Neuchâtel Observatory. The study confirmed the remarkable capability of Invar springs, which were installed in standard production watches from Moeris, Omega, Zénith, Tavannes, and Longines. The latter company strongly endorsed the springs, which quickly became a commercial success for FSR.

Reports suggest that it was Paul Baehni who was responsible for the purchase by FSR, though he did not serve on the board. However, as Perret's springs gained market share, the cartel decided to transfer production to the Baehni family workshop in Bienne as well as the new FSR factory in Geneva. In April, 1915, it was announced that the Fleurier workshop would be closed, with most senior workers moving to these other cities to continue their work.

Paul Perret's name continued to be used in association with Invar hairsprings, but over time the name of his Nobel Prize-winning collaborator Charles-Edouard Guillaume was more prominent. By the time the cartel system took over in the 1930s with the creation of ASUAG, Paul Perret was generally forgotten.

In 2014, a new watchmaking firm was established in La Chaux-de-Fonds using Paul Perret's name. This company leaned heavily on his legacy as a watchmaker and regulator but generally glossed over his achievements as an inventor and his role in the development of Invar hairsprings. The company did not find success and disappeared around 2021.