Biography of Henry Sully, by Julien Le Roy (1737)

Last updated on August 5, 2022

Written and translated by : Robert St-Louis, June 2020

Source: 1737, Henry Sully, Paris: Règle artificielle du temps.  Traité de la division naturelle & artificielle du temps, des horloges & des montres de différentes constructions, de la manière de les connoître & de les regler avec justesse.  433 pages.

First page of JLR’s memoir

In 1737 a new edition of Sully’s ground-breaking 1717 book “Règle artificielle du temps”, was carried out by the publisher Dupuis, assisted by the venerated French “horloger” Julien Le Roy, who had known Sully very well during his time in Paris.  Le Roy added several of his memoirs on horology in the second part of the book, and penned a very interesting document starting on page 381, entitled “Memoir to serve the history of horology from 1715 to 1729”.  

The majority of this memoir deals with Henry Sully, from his arrival in Paris around 1715, to his death in 1728.  LeRoy knew Sully very well during much of this period.  They were friends and worked together on advancing some aspects of watch-making during this important renewal period of French horology.  Because LeRoy lived through this tumultuous period of Sully’s life, consisting of alternating highs and lows, he was perfectly positioned to describe it, and offers a sympathetic portrait of his friend, who he called a “martyr” to the art of horology.  

A previous translation of this important document was published in 1842 in “Time and Timekeepers”, by the Englishman Adam Thomson.  However, Thomson did not translate the text in its entirety, and took some editorial liberties with it. The document I prepared and which follows, contains both Thompson’s incomplete earlier translation of Le Roy’s memoir, as well as my recent, rather literal and complete translation of the original Le Roy document.

Julien Le Roy’s memoir is as close as we will ever get to a contemporary biography of Henry Sully, written by his friend who knew him well.



  1. Vincent Victor Cherico Jr. said:

    This has to be a stand alone book. Fantastic.
    Thanks Vin

    May 24, 2021
    • Robert said:

      Thank you Vin.
      Well, if I ever manage to pull all my Sully research into a book, this biographical memoir by his friend Julien Le Roy will definitely be a key element!
      Regards, Robert.

      May 25, 2021

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