Huygens, Christian

, a very celebrated mathematician and astronomer, was born at the Hague April 14, 1629, and was son of Constantino Huygens, lord of Zuylichem, who had served three successive princes of Orange in the quality of secretary, and had spent his whole life in cultivating the mathematics not in the speculative way only, but in making them subservient to the uses of life., From his infancy our author applied himself to this study, and made a considerable progress in it, even at nine years of age, as well as in music, arithmetic, and geography; in all which he was instructed by his father, who in the mean time did not suffer him to neglect the belles lettres. At thirteen he was initiated in the study of mechanics; having discovered a wonderful curiosity in examining machines and other pieces of mechanism; and two years after had the assistance of a master in mathematics, under whom he made surprising progress. In 1645 he went to study law at Leyden, under Vinnius; yet did not attach himself so closely to that science, but that he found time to continue his mathematics under the professor Schooten. He left this university at the end of one year, and went to Breda, where an university had just been founded, and placed under the direction of his father; and here, for two or three years, he made the law his chief study. In 1649 he went to Holstein and Denmark, in the retinue of Henry count of Nassau; and was extremely desirous of going to Sweden to visit Des Cartes, who was then in that country with the queen Christina, but the count’s short stay in Denmark would not permit him. In 1651, he gave the world a specimen of his genius for mathematics, in a treatise entitled “Theoremata de quadratura Hyperboles, Ellipsis, & Circuli, ex dato portionum gravitatis centro” in which he shewed very evidently what might be expected from him afterwards.

In 1655 he travelled into France, and took the degree of doctor of laws at Angiers. In 1658 he published his | “Horologium oscillatorium, sive de motu pendulorum,” &c. at the Hague. He had exhibited in a preceding work entitled “Brevis institutio de usu HorologioKum ad inveniendas longitudines,” a model of a new invented pendulum; but as some persons envious of his reputation were labouring to deprive him of the honour of the invention, he wrote this book to explain the construction of it, and to shew that it was very different from the pendulum of astronomers invented by Galileo. In 1659 he published his “Systema Saturninum, sive de causis mirandorum Saturni phenomenon, & comiteejus planeta novo.” Galileo had endeavoured to explain some of the surprising appearances of the planet Saturn. He had at first perceived two stars which attended it; and some time after was amazed to find them disappear. Huygens, desirous to account for these changes, laboured with his brother Constautine to bring the telescopes to greater perfection; and made himself glasses by which he could view objects at a greater distance than any that had yet been contrived. With these he applied himself to observe all the phases and appearances of Saturn, and drew a journal of all the different aspects of thai planet. He discovered also one of the satellites belonging to that planet, which had hitherto escaped the eyes of astronomers; and, after a long course of observations, perceived that the planet is surrounded with a solid and permanent ring, which never changes its situation. These discoveries gained him an high rank among the astronomers of his time.

In 1660 he took a second journey into France, and the year after passed over into England, where he communicated his art of polishing glasses for telescopes, and was made a fellow of the royal society. About this time the air-pump was invented, which received considerable im-rprovements from him. This year also he discovered the laws of the collision of elastic bodies: as did afterwards our own countrymen, the celebrated Wallis and Wren, with whom he had a dispute about the honour of this discovery. After he had stayed some months in England, he returned to France in 1663, where his merit became Sq conspicuous, that Colbert resolved to fix him at Paris, by settling on him a considerable pension. Accordingly, in. 1665, letters written in the king’s name were sent to him to the Hague, where he then was, to invite him to Paris, with, the promise of a large stipend, and other considerable | advantages. H.uygens consented to the proposal, and resided at Paris from 1666 to 1681; where he was made a member of the royal academy of sciences. During this time he was engaged in mathematical pursuits, wrote several works, which were published from time to time, and invented and perfected several useful instruments and machines. But continual application hegan then to impair his health; and, though he had twice visited his native air, in 1670 and 1675, for the sake of recovering from illness, he now found it permanently necessary to his constitution; but perhaps the revocation of the edict of Nantz was a principal reason for his wishing to return to his own country. Though he was assured that he should enjoy the same liberty as before, and not be molested for his religions opinions, he would not consent to live in a country where his religion was proscribed, and therefore left Paris in. 3681, and passed the remainder of his life in his own country, occupied in his usual pursuits and employments. He died at the Hague June 8, )695, in his sixty-seventh year, while his “Cosmotheoros,” a Latin treatise concerning the plurality of worlds, was printing; he provided, however, in his will for its publication, desiring his brother Constantine, to whom it was addressed, to take that trouble upon him. But Constantine was so occupied with business, as being secretary in Holland to the king of Great Britain, that he died also before it could be printed; so that the book did not appear in public till 1698.

In 1703 were printed at Leyden, in 1 vol. 4to, Hnygens’s “Opuscula Posthuma, quse continent Dioptricam, Commentaries de vitris figurandis, Dissertationem de Corona & Parheliis, Tractatum de motu & de vi centrifuga, descriptionem Automati Planetarii.” Huygens had left by will to the university of Leyden his mathematical writings, and requested de Voider and Fullenius, the former professor of natural philosophy and mathematics at Leyden, and the other at Franeker, to examine these works, and publish what they should think proper. This was performed in the volume here mentioned. Huygens had written in Low Dutch the second of the tracts it contains, relating to the art of forming and polishing telescope -glasses, to which he had greatly applied himself; and Boerhaave translated it into Latin for this work. In 1700, were published in 4to, his “Opera Varia.” This collection is generally bound in 4 volumes. It contains the greatest part | of the pieces which he had published separately, and is divided into four parts. The first part contains the pieces relating to mechanics; the second, those relating to geometry; the third, those relating to astronomy; and the fourth, those which could not be arranged under any of the former titles. Gravesancle had the care of this edition, in which he has inserted several additions to the pieces contained in it, extracted from Huygens’s manuscripts. In 1728 were printed at Amsterdam, in 2 vols. 4to, his “Opera lleliqua;” which new collection was published also by Gravesande. The first volume contains his “Treatises on Light and Gravity;” the second his “Opuscula Posthuma,” which had been printed in 1703. His whole time had been employed in curious and useful researches. He loved a quiet and studious life; and perhaps through fear of interruption, never married. He was an amiable, chearful, worthy man; and in all respects as good as he was great. As an inventor, the first and not the least considerable of his discoveries was that he made of the real nature, or rather figure of the luminous appearance which accompanies the planet Saturn; but the most important was his pendulum clock and his micrometer. His history, however, includes many controversies respecting priority in these inventions, which may be seen at large in our authorities. ¹