Halley, Edmond

born Nov. 8, 1656, Haggerston, Shoreditch, near London

died Jan. 14, 1742, Greenwich, near London

English astronomer and mathematician.

He studied at the University of Oxford. In 1676 he set sail for the South Atlantic with the intention of compiling an accurate catalog of the stars of the Southern Hemisphere. His star catalogue (1678) recorded the position of 341 stars. In 1684 he met Isaac Newton at Cambridge, which led to his prominent role (with Robert Hooke and Christopher Wren) in the development of Newton's law of gravitation. Halley edited Newton's Philosophiae Naturalis Principia Mathematica, bringing it to print in 1687. He produced the first meteorological chart (1686, showing the distribution of prevailing winds in the world's oceans) and magnetic charts of the Atlantic and Pacific (1701). In astronomy, he described the parabolic orbits of 24 comets observed in the years 1337–1698. He showed that three of these were so similar that they must have been the same comet, and he accurately predicted its return in 1758 (see Halley's Comet).

Halley, detail of an oil painting by R. Phillips, c. 1720; in the National Portrait Gallery, ...

By courtesy of the National Portrait Gallery, London

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▪ British scientist

Introduction

Edmond also spelled  Edmund  

born Nov. 8, 1656, Haggerston, Shoreditch, near London

died Jan. 14, 1742, Greenwich, near London

 English astronomer and mathematician who was the first to calculate the orbit of a comet later named after him. He is also noted for his role in the publication of Newton's Philosophiae Naturalis Principia Mathematica.

Early life.

      Halley began his education at St. Paul's School, London. He had the good fortune to live through a period of scientific revolution that established the basis of modern thought. He was four years old when the monarchy was restored under Charles II; two years later the new monarch granted a charter to the informal organization of natural philosophers originally called the “invisible college,” which then became known officially as the Royal Society of London. Halley entered Queen's College, Oxford, in 1673 and there was introduced, by letter, to John Flamsteed (Flamsteed, John), who was appointed astronomer royal in 1676. On one or two occasions Halley visited the Royal Greenwich Observatory, where Flamsteed did his work, and there was encouraged to study astronomy.

      Influenced by Flamsteed's project of using the telescope to compile an accurate catalog of northern stars (star), Halley proposed to do the same for the Southern Hemisphere. With financial assistance from his father and, from King Charles II, an introduction to the East India Company, he sailed in November 1676 in a ship of that company (having left Oxford without his degree) for the island of St. Helena, the southernmost territory under British rule, in the South Atlantic. Bad weather frustrated his full expectations. But, when he embarked for home in January 1678, he had recorded the celestial longitudes and latitudes of 341 stars, observed a transit of Mercury across the Sun's disk, made numerous pendulum observations, and noticed that some stars apparently had become fainter since their observation in antiquity. Halley's star catalog, published late in 1678, was the first such work to be published containing telescopically determined locations of southern stars, and it established his reputation as an astronomer. In 1678 he was elected a fellow of the Royal Society and, with the intercession of the King, was granted the M.A. degree from Oxford University.

Halley and Newton.

      In 1684 Halley made his first visit to Sir Isaac Newton (Newton, Sir Isaac) in Cambridge, an event that led to his prominent role in the development of the theory of gravitation. Halley was the youngest of a trio of Royal Society members in London that included Robert Hooke (Hooke, Robert), the inventor and microscopist, and Sir Christopher Wren (Wren, Sir Christopher), the famous architect, both of whom, with Newton at Cambridge, were attempting to find a mechanical explanation for planetary motion. Their problem was to determine what forces would keep a planet in forward motion around the Sun without either flying off into space or falling into the Sun. Since these men were dependent upon their scientific stature for both livelihood and sense of achievement, each had a personal interest in being the first to find a solution. This desire for priority, a propelling motive in science, was the cause of much lively discussion and competition between them.

      Although Hooke and Halley had calculated that the force keeping the planets in orbit decreased as the inverse of the square of the distances between them, they were not able to deduce from this hypothesis a theoretical orbit that would match the observed planetary motions, despite the incentive of a prize offered by Wren. Halley then visited Newton, who told him he had already solved the problem—the orbit would be an ellipse—but that he had mislaid his calculations to prove it. Encouraged by Halley, Newton then expanded his studies on celestial mechanics into one of the greatest masterpieces produced by the mind of man, the Principia. The Royal Society decided that “Mr. Halley undertake the business of looking after it, and printing it at his own charge,” which he proceeded to do. He consulted with Newton, tactfully subdued a priority dispute between Newton and Hooke, edited the text of the Principia, wrote laudatory verse in Latin for the preface to honour its author, corrected the proofs, and saw it through the press in 1687.

Later works.

      Halley had the ability to reduce large amounts of data to a meaningful order. In 1686 his map of the world, showing the distribution of prevailing winds over the oceans, was the first meteorological chart to be published. His mortality tables for the city of Breslau, published in 1693, comprised one of the first attempts to relate mortality and age in a population; as such, it influenced the future development of actuarial tables in life insurance. Under instructions from the Admiralty, he commanded the war sloop Paramour Pink in 1698–1700 on the first sea voyage undertaken for purely scientific purposes, this one to observe variations in compass readings in the South Atlantic and to determine accurate latitudes and longitudes of his ports of call. In 1701 he published the first magnetic (magnetism) charts of the Atlantic and Pacific areas, showing curved lines that indicated positions in the oceans having the same variation of the compass. Such charts, compiled from all available observations and augmented with many of his own made on sea voyages, were of great practical value in navigation and were used for many years after his death. Notwithstanding opposition from Flamsteed, Halley in 1704 was appointed Savilian professor of geometry at Oxford.

      Continuing his pioneering work in observational astronomy, Halley published in 1705 A Synopsis of the Astronomy of Comets, in which he described the parabolic orbits of 24 comets (comet) that had been observed from 1337 to 1698. He showed that the three historic comets of 1531, 1607, and 1682 were so similar in characteristics that they must have been successive returns of the same visitant—now known as Halley's Comet—and accurately predicted its return in 1758.

      In 1716 he devised a method for observing transits of Venus across the disk of the Sun, predicted for 1761 and 1769, in order to determine accurately, by solar parallax, the distance of the Earth from the Sun. In 1720 Halley succeeded Flamsteed as astronomer royal at Greenwich, where he made observations, such as timing the transits of the Moon across the meridian, that he hoped would eventually be useful in determining longitude at sea.

Halley's significance.

      Halley's concern with practical applications of science, such as problems of navigation, reflects the influence on the Royal Society of Francis Bacon (Bacon, Francis, Viscount Saint Alban (or Albans), Baron of Verulam), who held that science should be for the “relief of man's estate.” Though wide ranging in his interests, Halley displayed a high degree of professional competence that foreshadowed scientific specialization. His wise assessment of Newton's work and his persistence in guiding it to completion earned for him an important place in the emergence of Western thought.

Olin Jeuck Eggen

Additional Reading

Eugene Fairfield MacPike (ed.), Correspondence and Papers of Edmond Halley (1932), collects contemporary materials. More recent studies include Colin A. Ronan, Edmond Halley: Genius in Eclipse (1969); A. Armitage, Edmond Halley (1966); Peter Lancaster-Brown, Halley & His Comet (1985); and Norman J.W. Thrower (ed.), Standing on the Shoulders of Giants: A Longer View of Newton and Halley (1990).

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