Achille Brocot

Achille Brocot (pronounced "broco") (11 July 1817 – 19 January 1878) was a French clockmaker and amateur mathematician.

He is known for his discovery (contemporaneously with, but independently of, German number theorist Moritz Stern) of the Stern–Brocot tree, a mathematical structure useful in approximating real numbers by rational numbers; this sort of approximation is an important part of the design of gear ratios for clocks.

He also made many practical horological innovations including refinement of his father Louis-Gabriel's Brocot escapement and the development of clocks with perpetual calendar mechanisms. In order to commercially exploit his original designs, together with Jean-Baptiste Delettrez he established the clockmaking company "Brocot & Delettrez" in Paris on 20 October 1851, a partnership that would continue until his death.

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