With this improved telescope, he discovered Titan, one of Saturn's moons, in 1655, and was able to provide the first accurate description of the rings of Saturn.

In 1655 he devised a new method of grinding and polishing lenses, and this provided a much sharper definition. Xxxxx But his talent proved no less remarkable in his study of astronomy. He also did some work on the theory of probabilities, a topic which was also being studied at this time by his acquaintance, the brilliant French mathematician Blaise Pascal. His first two essays - Exetasis quadraturae circuli and Theorema de quadratura hyperboles - confirmed his exceptional ability in this subject, and his De Circuli Magnitudine Inventa of 1654 earned him a European reputation. During this period he made advances in both pure and applied mathematics. Xxxxx A loyal if somewhat critical disciple of the French scientist and philosopher René Descartes, he was particularly brilliant at mathematics, and devoted most of his early years to this aspect of his work. During his working life he lived in Denmark, Holland, France and England, but he spent some 15 years at both The Hague and the Bibliothèque Royale in Paris. After private tuition he studied at Leiden University and the College of Breda, and began his research in earnest in 1651. His father, Constantijn Huygens, was a well- known poet and a senior diplomat. Xxxxx The Dutchman Christiaan Huygens, one of the most outstanding scientists of his age, was born at The Hague.

On a visit to England, he met Isaac Newton and influenced some aspects of his work. A disciple of René Descartes, he numbered among his friends Antoni van Leeuwenhoek, Gottfried Leibniz and Blaise Pascal. His last work, Cosmotheoros, delved into the idea of extraterrestrial forms of life.

In 1657 he patented the first workable pendulum clock, and his research in this field was later set out in his Horologium Oscillatorium of 1673. Of practical use was his work on a weight- driven timepiece. A later work, Traité de la lumière of 1678, included his pulse theory of light, and his discovery of the polarization of light. These and other findings were contained in his Systema Saturnium, published in 1659. In astronomy, having improved the making of lenses, he discovered Titan, and accurately described the rings of Saturn. Xxxxx The Dutchman Christiaan Huygens, an outstanding scientist, gained an early reputation as a mathematician with his work of 1654, De Circuli Magnitudine Inventa.

De circuli magnitudine inventa lenses