Jean Hautefeuille, the son of a French _boulanger_, born at Orleans, adopted by the Duchess of Bouillon at the suggestion of De Sourdis, profiting by the great opportunities offered him, entered the Church, and became one of the most learned men and greatest mechanicians of his time. He studied the many schemes then brought forward by inventors with the greatest interest, and was himself prolific of new ideas. In 1678, he proposed the use of alcohol in an engine, "in such a manner that the liquid should evaporate and be condensed, _tour à tour_, without being wasted"[16]--the first recorded plan, probably, for surface-condensation and complete retention of the working-fluid. He proposed a gunpowder-engine, of which[17] he described three varieties. [16] Stuart's "Anecdotes." [17] "Pendule Perpetuelle, avec la manière d'élever d'eau par le moyen de la poudre à canon," Paris, 1678. In one of these engines he displaced the atmosphere by the gases produced by the explosion, and the vacuum thus obtained was utilized in raising water by the pressure of the air. In the second machine, the pressure of the gases evolved by the combustion of the powder acted directly upon the water, forcing it upward; and in the third design, the pressure of the vapor drove a piston, and this engine was described as fitted to supply power for many purposes. There is no evidence that he constructed these machines, however, and they are here referred to simply as indicating that all the elements of the machine were becoming well known, and that an ingenious mechanic, combining known devices, could at this time have produced the steam-engine. Its early appearance should evidently have been anticipated. Hautefeuille, if we may judge from evidence at hand, was the first to propose the use of a piston in a heat-engine, and his gunpowder-engine seems to have been the first machine which would be called a heat-engine by the modern mechanic. The earlier "machines" or "engines," including that of Hero and those of the Marquis of Worcester, would rather be denominated "apparatus," as that term is used by the physicist or the chemist, than a machine or an engine, as the terms are used by the engineer. Huyghens, in 1680, in a memoir presented to the Academy of Sciences, speaks of the expansive force of gunpowder as capable of utilization as a convenient and portable mechanical power, and indicates that he had designed a machine in which it could be applied.