Opera mechanica, geometrica, astronomica et miscellanea

HUGENII VITA.

HUGENII VITA.

many things in mathematics were discovered, and he composed various works from these, which, now collected into one body, place before our eyes what he achieved in various branches of mathematics.

Beyond the aforementioned illustrious inventions of his, two others stand out for their notable utility. He constructed a level equipped with a telescope in such a way that it could be trusted above all others original: "ita conſtruxit, ut ipfi præ ceteris fides haberi poffit". Another invention concerns the measurement of time; he adapted a steel, spiral, elastic wire i.e., a balance spring to portable clocks original: "Horologiis portatilibus"; which no portable clock is now without, and which, if removed, causes even the most accurately constructed timepieces to lose all regularity of motion.

* See page 254.

* See page 253.

However, being too devoted to mathematical studies, his body could not sustain the labor that was pleasing to his mind. For this reason, he traveled to Holland twice, in the years 1670 and 1675, and having recovered his health, he returned to France; but finally, in order to care for his health, he said farewell to it forever in the year 1681, and resigned all the King's benefits.

He completed the remainder of his life's course occupied with the same studies.

In the year 1682, he caused an Automaton Planetarium a mechanical planetary model to be constructed, in which he very beautifully emulated the motion of the planets on a plane.

This machine is delineated and most accurately described in his posthumous works. It still exists today with his heirs.