xxxxxThe Dutchman Christiaan Huygens, an outstanding scientist, gained an early reputation as a mathematician with his work of 1654, De Circuli Magnitudine Inventa. In astronomy, having improved the making of lenses, he discovered Titan, and accurately described the rings of Saturn. These and other findings were contained in his Systema Saturnium, published in 1659. A later work, Traité de la lumière of 1678, included his pulse theory of light, and his discovery of the polarization of light. Of practical use was his work on a weight-driven timepiece. 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. His last work, Cosmotheoros, delved into the idea of extraterrestrial forms of life. A disciple of René Descartes, he numbered among his friends Antoni van Leeuwenhoek, Gottfried Leibniz and Blaise Pascal. On a visit to England, he met Isaac Newton and influenced some aspects of his work. Denis Papin was one of his assistants.

CHRISTIAAN HUYGENS  1629 - 1695  (C1, CW, C2, J2, W3)


Huygens: pastel portrait by the Dutch painter Bernard Vaillant (1632-1698), 1686 – Huygensmuseum, Hofwijck, Voorburg, Netherlands.

xxxxxThe Dutchman Christiaan Huygens, one of the most outstanding scientists of his age, was born at The Hague. His father, Constantijn Huygens, was a well-known poet and a senior diplomat. After private tuition he studied at Leiden University and the College of Breda, and began his research in earnest in 1651. 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.

xxxxxA 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 this period he made advances in both pure and applied mathematics. 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. 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.

xxxxxBut his talent proved no less remarkable in his study of astronomy. In 1655 he devised a new method of grinding and polishing lenses, and this provided a much sharper definition. 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. (The Italian scientist Galileo had seen the rings but, thinking they were attached to the planet, had called them "handles".) These and other findings, like the more accurate observation of the Orion Nebula - a vast cloud of gas and dust -, and the discovery of the black marking on the surface of Mars (known as Syrtis major), were later contained in his Systema Saturnium, published in 1659.

xxxxxAs a physicist he proposed the wave or pulse theory of light (rejecting Isaac Newton's corpuscular theory), and also discovered the polarisation of light, both concepts being expounded at length in his Traité de la lumière of 1678. He met Newton when he visited England in 1689, and there is little doubt that his research into centrifugal force was of assistance to the English scientist in formulating the laws of gravity. But Huygens is perhaps best remembered today for his development of the pendulum as a means of accurately regulating the movement of a weight-driven timepiece (an idea conceived earlier by Galileo but never fully exploited). In 1657 he patented the first practical pendulum clock, thus increasing the interest in time-keeping, and paving the way for the long-case or grandfather clock. Details of this research - notably the correlation between the length of the pendulum and the period of oscillation - were later set out in his Horologium Oscillatorium, published in 1673.

xxxxxWe are told that René Descartes, a friend of the family, once predicted that Huygens would attain greatness. It was a valid prediction. Such was his standing in the academic world that in 1666 he was appointed one of the founder members of the French Academy of Sciences. Among his large circle of influential friends were the Dutch microscopist Antoni van Leeuwenhoek, and the German philosopher Gottfried Leibniz, who sought his guidance in mathematics and physics while living in Paris during the 1670s. And numbered among his assistants was the French-born English inventor Denis Papin, who later played a vital part in the development of a practical air pump and pressure cooker.

xxxxxHuygens never enjoyed good health and, indeed, came near to dying in 1670. After a further bout of serious illness, he returned to Holland in 1681 and two years later, following the death of his patron, Jean-Baptiste Colbert (chief minister to king Louis XIV of France), decided not to return to Paris. It was at this time that he became interested in extraterrestrial forms of life. He discussed the possibility of there being life on planets revolving around the sun and other stars in his work Cosmotheoros, published posthumously in 1698. He died at The Hague in 1695 after five years of continual ill-health.

xxxxxIncidentally, it was around 1678 that Huygens designed the first internal combustion engine, fuelled by gunpowder. It never left the drawing-board, but his assistant, Denis Papin, continued this line of research, and was the first to put forward the idea of a cylinder and piston steam engine, though, once again, a prototype was never built.