While Newton, in England, was thus enlarging the boundaries of astronomy, and conferring upon it a degree of accuracy and system hitherto unknown, a number of continental philosophers were contributing materials, which, though of an humble character, were not the less necessary to the future progress of the science. First among these was Christian Huygens, Lord of Zeelhem, born at the Hague on the 14th of April 1629, and descended of a rich and respected family. His father, secretary and counselor to the Princess of Orange, and distinguished as a scholar and poet, was not slow in observing the genius of his son, and, full of paternal solicitude for his improvement, became his first instructor. He early taught him music, arithmetic, and geography - says a writer in the Encyclopaedia, from which we select the materials of this notice - and initiated him, when about thirteen, in the knowledge of mechanics, for which the boy had evinced a surprising aptitude. At fifteen, he received the assistance of a master in mathematics, under whose tuition he made great progress; and at sixteen, was sent to Leyden, to study law under the eminent jurisconsult Vinnius. He did not, however, permit jurisprudence to divert him from his mathematical studies, which he now prosecuted with success as well as afterwards at Breda, at the university of which he resided from 1646 to 1648. In these two cities he had respectively as masters two very able geometers, Francis Schooten and John Pell; and his first essays were so successful, that they attracted the notice of Descartes, to whom the author, in his admiration of that great philosopher, had communicated them. Descartes predicted his future greatness, but did not live to appreciate his discoveries.

On quitting the university, Huygens, as was then the custom, made the tour of Europe; and after his travels, settled in his native country, where he commenced that series of inventions which have rendered his name so justly celebrated. Between the years 1650-60, his pursuits were chiefly mathematical, resulting in several publications of acknowledged merit. In 1655 he traveled into France, and took the degree of Doctor of Laws at Angers; and in 1658 made known his invention of the pendulum clock. In the following year he published his discoveries relative to the planet Saturn; discoveries which inseparably associate his name with the science of astronomy. Galileo had endeavored to explain some of the appearances exhibited by that planet. He had at first observed two attendant stars, but some time afterwards was surprised to find that they had disappeared. Huygens, desirous to account for these changes, labored with his brother Constantine to improve the construction of telescopes; and having at length made an instrument of this kind, possessing greater power than any which had yet been contrived, he proceeded to observe the phases of Saturn, and to record all the different aspects of that planet. The results were of equal interest and importance to the science of astronomy. He discovered a satellite of that planet which had hitherto escaped the notice of astronomers; and after a long course of observation, he showed that the planet is surrounded by a solid and permanent ring, which never changes its situation. In 1660 he took a second journey into France; and the year following he visited England, where he communicated the art of polishing glasses for telescopes, and was admitted a member of the Royal Society. The air-pump, then recently invented, he materially improved; and about the same time he also discovered the laws of the collision of elastic bodies, as did afterwards Wallis and Wren, who disputed with him the honor of the discovery. After a stay of some months in England, Huygens returned to France, where, in 1633, his merit became so conspicuous, that Colbert resolved to bestow on him such a pension as might induce him to establish himself at Paris. This resolution was not carried into effect until 1665, when letters in the king's name were written to the Hague, where the philosopher then resided, inviting him to repair to Paris, and offering him a considerable pension, with other advantages. Huygens accepted the proposal; and from 1666 to 1681, settled at Paris, where he was admitted a member of the Royal Academy.

During this period he was chiefly engaged in mathematical pursuits: he wrote and published several works, which were favorably received; and he invented and improved some useful instruments and machines. By continued application, his health began to be impaired, and he at length found it necessary to return to his native country a step somewhat accelerated by the revocation of the Edict of Nantes, which rendered him liable to molestations, although assured of the fullest privilege to follow his own religious opinions. He accordingly left the French metropolis in 1681; passed the remainder of his days in his own country, and in the pursuit of his favorite subjects; and died at the Hague on the 8th of June 1683, in the sixty-seventh year of his age. This illustrious man,' continues our authority, gave his whole time to science; he loved a quiet studious life, and found sufficient enjoyment in pursuing curious and useful researches. He was modest, amiable, cheerful, and in all respects as estimable in private life as he was eminent in science. It is not a little singular that the discovery of the real nature, or at least of the true figure, of the luminous ring which encompasses the planet Saturn, should have been made by the same individual who invented the pendulum clock and the micrometer.' His inventions, however, were more of a mathematical and mechanical than of an astronomical character; and we safely predict, that had Huygens lived in the present day, he would have risen to superlative fame as a mechanician and engineer.