Hautefeuille, John

, an ingenious mechanic, born at Orleans, March 20, 1647, made a great progress in mechanics in general, but had a particular taste for | clockwork, and made several discoveries in it that were of singular use. He found out the secret of moderating the vibration of the balance by means of a small steelspring, which has since been made use of. This discovery he laid before the members of the academy of sciences in 1694 and these watches are, by way of eminence, called pendulum-watches not that they have real pendulums, but because they nearly approach to the justness of pendulums. M. Huygens perfected this happy invention; but having declared himself the inventor, and obtained a patent for making watches with spiral springs, the abbe* Feuille opposed the registering of it, and published a piece on the subject against Huygens. He died in 1724. Besides the above, he wrote a great many other pieces, most of which are small pamphlets, but very curious; as, 1. His “Perpetual Pendulum.” 2. “New Inventions.” 3. “The Art of Breathing under Water, and the means of preserving a Flame shut up in a small place.” 4. “Reflections on Machines for raising water.” 5. His opinion on the different sentiments of Mallebranche and Regis, relating to the appearance of the Moon when seen in the horizon. 6. “The Magnetic Balance.” 7. “A Placet to the king on the Longitude.” 8. “Letter on the secret of the Longitude.” 9. “A New System on the Flux and Reflux of the Sea.” 10. “The means of making sensible experiments that prove the Motion of the Earth;” and many other pieces. ¹