Halley, Edmund

, an eminent English philosopher and astronomer, was born at Haggerston, in the parish of St. Leonard, Shoreditch, near London, October 29, 1656. His father, a wealthy soap-boiler in Winchester-street, put him to St. Paul’s school, under the learned Dr. Thomas Gale, but his h’rst tutor is said to have been his father’s apprentice, who taught him writing and arithmetic at nine years old. At school he not only excelled in all parts of classical learning, but made such uncommon progress in mathematics, that, as Wood says, he had perfectly learnt the use of the celestial globe, and could make a complete dial; and we are informed by Halley himself, that he observed the change of the variation of the magnetic needle at London, in 1672, that is, one year before he left school. In 1673 he was entered a commoner of Queers-college, in Oxford, where he applied himself to practical and geometrical astronomy, in which he was greatly assisted by a curious apparatus of instruments which his father, willing to encourage his son’s genius, had purchased for him. At nineteen he began to publish | new observations and discoveries, and continued to do so to the end of a very long life; nor did he distinguish himself less in the practical part of the science. Several observations made by him concerning a spot in the sun, seen at Oxford in July and August 1676, were published, with others by Flamsteed upon the same subject, in the Philosophical Transactions. By these the motion of the sun round its own axis, a phenomenon till then not well ascertained, was finally determined. The same year he likewise observed there, on Aug. 21, a.n occultation of Mars by the Moon, which he made use of afterwards, with others, in settling the longitude of the Cape of Good Hope against the objections of the French astronomers.

He had from his first admission into college, pursued a general scheme for ascertaining the true places of the fixed stars, and thereby correcting the errors of Tycho Brahe. His original view was to carry on the design of that first restorer of astronomy, by completing the catalogue of those stars from his own observations; but upon farther inquiry, finding this province taken up by Hevelius and Flamsteed, he dropped that pursuit, and formed another; which was, to perfect the whole scheme of the heavens by the addition of the stars which lie so near the south pole that they could not be observed by those astronomers, as never rising above the horizon either at Dantzick or Greenwich. With this view he left the university, before he had taken a degree, and applied himself to sir Joseph Williamson, then secretary of state, and to sir Jonas Moore, surveyor of the ordnance, both encouragers of these studies; who, applauding his purpose, mentioned it to Charles II. The king was much pleased with the plan, and immediately recommended him to the East India Company, who readily promised to supply him with every convenience, and to carry him to St. Helena, then in their possession by a grant from the crown, which he had been told was a proper situation for his design. Accordingly he embarked for that island November 1676, and arriving there safely in three months, began his task; but the frequent fogs which hover over the island made it much more difficult than he expected, and it was only by embracing every opportunity which offered during his abode on the island, that he was enabled to execute his purpose. He ascertained the position of 350 Stars, and published an account of his labours in 1676, under the title of “Catalogus Stellarum Australian.” In | honour of his royal patron, he formed a new southern constellation, to which he gave the name of “Kobur Carolinum,” or the “Royal Oak.” During his stay at St. Helena, he had an opportunity of observing the transit of Mercury over the sun’s disk; an observation of some importance, because it could not be completely made in Europe, the sun not being risen in that country at the beginning of the transit. Having returned to England November 1678, the king, greatly satisfied, gave him, at his own request, a letter of mandamus to the university of Oxford for the degree of M. A. the words of which are, that “his majesty has received a good account of his learning as to the mathematics and astronomy, whereof he has gotten a good testimony by the observations he has made during his abode in the island of St. Helena.” This letter was dated November 18, and the same month he was also chosen fellow of the royal society. Indeed his catalogue of these southern stars merited particular honour; it was an entirely new acquisition to the astronomical world, and might not unaptly be called “Ccelum Australe eo usque incognitum;” and thence he acquired a just claim to the title, which by Flamsteed was not long after given him, the Southern Tycho.

In 1679 he was appointed by the royal society to go to Dantzick, for the satisfaction of Hevelius the consul, to adjust a dispute between him and our Hooke, about the preference of plain or glass sights in astroscopical instruments. He set out May 14 of this year, with a letter recommendatory from the society, and arrived at that city on the 26th. He waited on the consul immediately, and after some conversation, agreed to enter upon the business of his visit that same night; on which, and every night afterwards, when the sky permitted, the two astronomers made their observations together till July 18, when Halley left Dantzick, and returned to England. Here he continued till the latter end of the following year, 1680; when he set out upon what is usually called the grand tour, accompanied by the celebrated Mr. Nelson, who had been his school-fellow, and was his friend. They crossed the water in December to Calais; and in the mid-way thence to Paris, Haliey had, first of any one, a sight of the remarkable comet as it then appeared a second time that year in its return from the sun. He had the November before seen it in its descent, and now hastened to complete | his observations upon it, in viewing it from the royal observatory of France. That building had been finished not many years before; and Halley’s design in this part of his tour was to settle a friendly correspondence between the two royal astronomers of Greenwich and Paris; embracing in the mean time every opportunity of improving himself under so great a master as Cassini, as he had done before under Hevelius. From Paris he went with his fellow-traveller, by the way of Lyons, to Italy, where he spent a great part of the year 1681; but his affairs then calling him home, he left Mr. Nelson at Rome, and returned to England, after making some stay a second time at Paris.

Soon after his return to England, he married the daughter of Mr. Tooke, auditor of the Exchequer; and took a house at Islington, where he immediately set up his tube and sextant, and eagerly pursued his favourite study. In 1683 he published his “Theory of the Variation of the Magnetical Compass,” in which he supposes the whole globe of the earth to be one great magnet, having four rnagnetical poles or points of attraction, two near the north and two near the south pole. The same year also he entered early upon a new method of finding out the longitude by a most accurate observation of the moon’s motion. His pursuits are said to have been interrupted about this time by the death of his father, who having suffered greatly by the fire of London, as well as by a second marriage, into which he had imprudently entered, was found to have wasted his fortune. He soon, however, resumed his usual occupations; for, January 1684, he turned his thoughts to the theory of the planetary motions; and gravity occurred to him, as it bad done to Dr. Hooke, as the probable cause. But he could not satisfy himself as to the law according to which this power diminishes, and therefore first applied to Dr. Hooke and sir Christopher Wren; who not affording him any assistance, he went to Cambridge to Newton, who supplied him fully with what he had so ardently sought. But Halley having now found an immense treasure, could not rest till he had prevailed with the owner to enrich the public with it, and to this interview the world is in some measure indebted for the celebrated “Principia” of Newton, which were published in 1686; and Halley, who had the whole care of the impression by the direction of the royal society, presented it to James II, with a discourse of | his own, giving a general account of the astronomical part of that book. He also wrote some very elegant verses in Latin, which are prefixed to the “Principia.”

In 1685 he became clerk to the royal society, and seems, for several years about that period, to have been the principal person employed in drawing up the “Philosophical Transactions.” In 1687 he undertook to explain the cause of a natural phenomenon, which had till then baffled the researches of the ablest geographers. The Mediterranean Sea is observed not to swell in the least, although there is no visible discharge of the prodigious quantity of water which runs into it from nine large rivers, besides several small ones, and the constant setting-in of the current at the mouth of the Streights. His solution of this difficulty gave so much satisfaction to the society, that he received orders to prosecute these inquiries, in the course of which, having shewn by the most accurate experiments, how that great increase of water was actually carried off in vapours raised by the action of the sun and wind upon the surface, he proceeded with the like success to point out the method used by nature to return the said vapours into the sea. This circulation he supposes to be carried on by the winds driving these vapours to the mountains; where, being collected, they form springs, which uniting, becomte rivulets or brooks, and many of these again meeting in the valleys, grow into large rivers, emptying themselves at last into the sea; thus demonstrating in the most beautiful manner the way in which the equilibrium of receipt and expence is continually preserved in the universal ocean. In 1698 he was candidate for the Savilian professorship at Oxford, but lost it by the intervention of bishop Stillingtteet, who refused to recommend him, on account of his opinions, which were considered as unfavourable to Christianity. We shall find, however, that he was afterwards elected*.

Halley published his “Theory of the Variation of the Magnetical Compass,” as already observed, in 1683;

* Whiston, in the Memoirs of his ley should talk with him about it, which own Life, tells us from Dr. Bentlev, he did. But Halley was so sincere in that Halley “being thought of for sue-his infidelity, that he would not so cessor to the mathematical chair at Ox-much as pretend to believe the Chrisford, bishop Stilling&eet was desired tiau religiou, though he thereby was to recommend him at courti; but, hear-likely to lose a professorship; which ing that he was a sceptic and a ban-he did accordingly, and it was the terer of religion, the bishop scrupled given to Dr. Gregory.” fco be concerned, till his chaplain Bent. | which, though it was well received both at home and abroad, he found upon a review liable to great and insuperable objections. Yet the phenomena of the variation of the needle, upon which it is raised, being so many certain and indisputed facts, he spared no pains to possess himself of all the observations relating to it, he could possibly come at. To this end he procured an application to be made to king William, who appointed him commander of the Paramour Pink, August 19, 169S; with express orders to seek by observations the discovery of the rule of the variations, and, as the words of his commission run, “to call at his majesty’s settlements in America, and make such farther observations as are necessary for the better laying down the longitude and latitude of those places, and to attempt the discovery of what land lies to the south of the Western ocean.” He set out on this attempt November 24th following, and proceeded so far as to cross the line; but his men growing sickly and untractable, and his first lieutenant mutinying, he returned home in June 1699. After getting his lieutenant tried and cashiered, he sailed September following, a second time, having the same ship with another of less bulk, of which he had also the command. He traversed the vast Atlantic Ocean from one hemisphere to another, as far as the ice would permit him to go; and, in his way back touched at St. Helena, the coast of Brazil, Cape Verd, Barbadoes, Madeiras, the Canaries, the coast of Barbary, and many other latitudes, arriving in England in September 1700. Having thus furnished himself with a competent number of observations, he published in 1701, “A General Chart, shewing at one view the Variation of the Compass in all those seas where the English navigators were acquainted;” and was the first who laid a sure foundation for the discovery of the law or rule whereby the said variation changes all over the world. In 1775 the original journals of Dr. Halley’s two voyages were published by Mr. Alexander Dalrymple, in a thin quarto volume, but they are not of much value, and were obviously never intended for publication by Dr. Halley himself.

Halley had been at home little more than half a year, en he went in the same ship with another express commission from the king, to observe the course of the tides in cry part of the British channel at home, and to take the wigitude and latitude of the principal head-lands, in order | to lay down the coast truly. These orders were executed with his usual expedition and accuracy; and soon after his return he published, in 1702, a large map of the Britisli channel. The emperor of Germany having resolved to make a convenient and safe harbour for shipping in that part of his dominions which borders upon the Adriatic, Halley was sent this year by queen Anne to view the two ports on the Dalmatian coast, lying to that sea. He embarked November 27, went over to Holland, and passing thence through Germany to Vienna, proceeded to Istria, with a view of entering upon the execution of the emperor’s design; but, some opposition being given to it by the Dutch, it was laid aside. The emperor, however, presented him with a rich diamond ring from his finger, and gave him a letter of high commendation, written with his own hand, to queen Anne. He was likewise received with great respect by the king of the Romans, by prince Eugene, and the principal officers of that court. Presently after his arrival in England, he was dispatched again upon the same business; and, passing through Osnaburgh and Hanover, arrived at Vienna, and was presented the same evening to the emperor, who directly sent his chief engineer to attend him to Istria.

He returned to England November 1703; and, Wallis being deceased a few weeks before, Halley was appointed Savilian professor of geometry at Oxford in his room, and had the degree of LL. D. conferred upon him by that university. He was scarcely settled at Oxford when Aidrich, dean of Christ Church, engaged him to translate into Latin from the Arabic “Apollonius de Sectione llationis.” At the same time, from the account given of them by Pappus, he restored the two books, which are lost, of the same author, “De Sectione Spatii;” and the whole was published by him in one. volume, 8vo, at Oxford, 1706. Afterwards he took a share with his colleague, Dr. David Gregory, in preparing for the press the same Apollonius’s “Conies;” and ventured to supply the whole 8th book, which is lost, of the original. He likewise added Serenus on the “Section of the Cylinder and Cone,” printed from the original Greek, with a Latin translation, and published the whole, 1710, in folio; not to mention, that in the midst of all these publications the “Miscellanea Curiosa,” in 3 vols. 8vo, had come out under his direction in 1708. Jn 1713 he succeeded Dr. (afterwards sir) Haas Sloane, in | the post of secretary to the royal society; and, upon the death of Flamsteed in 1719, was appointed to succeed him at Greenwich by George I. which made Halley, that he might be more at liberty for the proper business of his situation, resign the post of secretary to the royal society in 1721.

Upon the accession of king George II. his consort queen Caroline thought proper to make a visit at the royal observatory; and, being pleased with every thing she saw, took notice that Dr. Halley had formerly served the crown as a captain in the navy; and she soon after obtained a grant of his half-pay for that commission, which he enjoyed from that time during his life. An offer was also made him of being appointed mathematical preceptor to the duke of Cumberland; but he declined that honour in consideration of his advanced age, and because he deemed the ordinary attendance upon that employment not consistent with the performance of his duty at Greenwich. In August 1729 he was admitted as a foreign member of the academy of sciences at Paris. About 1737 he was seized with a paralytic disorder in his right hand, which, it is said, was the first attack he ever felt upon his constitution: however, he came as usual once a week till within a little while before his death, to see his friends in town on Thursday, before the meeting of the royal society. His paralytic disorder increasing, his strength gradually wore away, and he came at length to be wholly supported by such cordials as were ordered by his physician Dr. Mead. He expired as he sat in his chair, without a groan, January 14, 1741-2, in his eighty-sixth year, and was interred at Lee, near Blackheath.

Halley’s astronomical tables, on which he laboured from 1725 till his death, were published in 1749, and were for many years the best and most complete with which astronomers were furnished, though of late years other tables have been constructed still more perfect, and entitled to a greater degree of confidence.

Dr. Halley was of a middle stature, inclining to tallness, of a thin habit of body, and fair complexion, and always spoke and acted with an uncommon degree of sprightliness and vivacity. He was of an ardent and glowing temper, of a generous and friendly disposition, and of great candour, He retained his good spirits to the last, and used to say “that a studious life generally contributes to make a long | one, by keeping a man out of harm’s way.” That he was, with all his learning and amiable qualifications, an infidel in religions matters, seems as generally allowed as it appears unaccountable. It must, however, be deeply regretted that he cannot be numbered with those illustrious characters who thought it not beneath them to be Christians, with Bacon and Milton, Boyle, Locke, and Newton. ¹