(Paris, L'Imprimerie Royale, 1750). 4to. Extract from ""Mémoires fe Mathematique et de Physique, Présentés à l'Academie des Sciences par divers Savans"", Tome I. Pp. 80-94 a. 3 engraved plates showing the machinery of the sand-timer.
Describing the construction of his advanced sand-timer to measure both minutes and hours mainly to be used at see.