crease, in proportion to the squares of the distances, reciprocally," he, after in vain seeking information from Hooke, and Sir Christopher Wren, applied to Newton, who satisfied all his inquiries, by shewing him the manuscript of his Principia, which, as we have related in our memoir of Sir Isaac, was afterwards published at the suggestion of Halley, and under his special superintendence. In 1685, he was appointed assistantsecretary to the Royal Society; and, in the following year, he satisfactorily accounted for a natural phenomenon, which till then had baffled the researches of the ablest geographers. This was the discovery of the reason why the Mediterranean never swells in the least, although there is no visible discharge of the immense quantity of water that runs into it from nine large rivers, besides several small ones, and the constant setting in of the current at the mouth of the streight. Mr. Halley solved this difficulty, by finding that this vast accession of water was carried off in vapours, raised by the action of the sun and wind upon its surface, and returned again to the sea by the winds driving these vapours to the mountains, where, being collected, they form springs, the streams from which uniting, become rivulets or brooks; and many of these again meeting in the vallies, grow into large rivers, which again empty themselves into the sea.

In 1691, he became an unsuccessful candidate for the Savilian professorship of astronomy, at Oxford; an office which, according to Whiston, he lost, in consequence of being "a sceptic, and a banterer of religion," though the writer of his life, in The Biographia Britannica, ascribes it principally to the machinations of Flamsteed. In 1692, he published his Tables, shewing the value of Annuities for Lives, calculated from the bills of mortality at Breslaw, in Silesia, one of the most known and useful tracts that ever came from his pen. In the same year, he resigned his appointment of assistant-secretary to the Royal Society; but continued, for several years, to be one of the most valuable contributors to their Transactions. In 1696, on the establishment of five mints for the silver re-coinage, he was appointed comptroller of the one at Chester, where he resided for

two years. In 1698, having in view the substantiation of his theory respecting the variation of the compass, he obtained, from William the Third, the command of a vessel, called the Paramour Pink, with express orders to seek, by observation, the discovery of the rule of the variation. The insubordination of his officers, compelled him to put back home, just as he had crossed the line; but, in the September of the following year, he again set out, and after having traversed both hemispheres, as far as the ice would permit him, he returned, by way of St. Helena, to England, in the autumn of 1700. The spot, where he made his astronomical observations in the former island, has been since marked out by the erection of a telegraph, and the appellation of Halley's Mount. In 1701, he published, as the result of his researches, A General Chart, shewing, at one view, the variation of the compass in all those seas where the English navigators were acquainted; by which he was the first to lay the true foundation of a discovery, which his biographer deservedly calls "one of the most useful benefactions that mankind ever received from a fellow-creature."

He was shortly afterwards commissioned to observe the course of the tides in the British channel, and to take the longitude and latitude of the principal headlands, which he executed with great skill; and, on his return, in 1702, published a large map of the British channel. In 1703, he was engaged, by the Emperor of Germany, to survey the coast of Dalmatia, and on his return, in November, he was appointed Savilian professor of geometry, at Oxford, on the decease of Dr. Wallis; and at the same time was presented with the degree of LL.D. His next employment was in the translation, from Arabic into Latin, of Apollonius de sectione rationis ; a task which had been given up by Dr. Bernard, as too difficult to complete. Halley, however, although at the time he was perfectly ignorant of the Arabic, accomplished his undertaking in such a manner, as to call forth the approbation and astonishment of the first oriental scholars. He then turned his attention to the Conic Sections of Apollonius, in which he assisted his colleague, Dr. David Gregory; and

the eighth book of the original being lost, the whole of it was supplied by Halley.

In November, 1713, he succeeded Sloane in the post of secretary to the Royal Society; and, in 1715, he had, with regard to the syzigies, or conjunctions, so far perfected his theory of the moon's motion, that he not only predicted, within a very few minutes, the central eclipse of the sun, which happened in that year, but also drew a map, in which he represented the extent of the moon's shadow, with surprising exactness. This at once confirmed him in the reputation of a firstrate astronomer, especially on a calculation of the same eclipse, by Whiston and Flamsteed, on whose death, in 1719, the subject of our memoir succeeded to his post of astronomer-royal. On his removal to Greenwich, he resumed, with indefatigable zeal, his lunar observations; and, for eighteen years, he is said to have scarce lost a meridian view of the moon, whether by day or by night, as often as the heavens would permit. In order to devote himself more uninterruptedly to his favourite pursuit, he, in 1721, resigned his secretaryship to the Royal Society; and, for the same reason, he subsequently declined becoming mathematical preceptor to the Duke of Cumberland. On the accession of George the Second, he was visited, at Greenwich, by Queen Caroline, who procured him half-pay, as a captain in the navy; and, in 1729, he was admitted as a foreign member of the Academy of Sciences, at Paris. He continued to prosecute his tedious and difficult researches respecting the moon's theory, until the period of his death, which took place on the 14th of January, 1741-2.

In person, Mr. Halley is described "of a middle stature, inclining to tallness; of a thin habit of body, and a fair complexion." His éloge was pronounced, in the French Academy, by M. Mairan, who gave an oratorical account of the universality of his genius, and the boldness of his philosophical hypotheses. Among others, he supposed the age of the world to be greater than is usually inferred from the Mosaic history, and that the length of the six days of the creation extended, each of them, to a thousand years; being of

opinion that such a duration was not inconsistent with anything delivered by Moses. Mr. Halley made an important improvement in Davis's quadrant; and, in addition to the works already mentioned, he published Miscellanea Curiosa, in three volumes, octavo; and, in 1752, appeared his Astronomical Tables, with precepts, both in English and Latin, for computing the places of the sun, moon, planets, and comets. His papers were, for many years, the chief ornament and support of the Philosophical Transactions, being about twenty-five or thirty dissertations, all abounding with ideas, new, singular, and useful. They relate chiefly to the quantity of vapour which the sun raises from the sea; the circulation of vapours; the origin of fountains; questions on the nature of light, and transparent bodies; a determination of the degrees of mortality; and many other works in astronomy, geometry, algebra; optics and dioptrics; ballistics and artillery; speculative and experimental philosophy; natural history, antiquities, philology, and criticism. The character of Mr. Halley appears to have been estimable; he was of an ardent and generous disposition, pleasing and affable in his manners, punctual and open in his dealings, candid in his judgment, and no less ready to communicate, than he was diligent to acquire knowledge. He was cheerful and animated to the last; and it is said that the palsy itself, which attacked him some years before his death, could not impair his natural vein of gaiety and good-humour. With respect to his unbelief in matters of religion, "it is not now possible," says one of his biographers," to ascertain the cause; whether to his dissatisfaction, as a geometrician, with the subtleties of scholastic systems of faith, with which the pure doctrines of the Christian religion are too often confounded; or, as is no uncommon case for men of letters and science, his being so deeply engaged in his favourite speculations, as to disregard and despise inquiries not immediately connected with objects of his researches." He lived in the reigns of six British monarchs, from each of whom he received marked favour; and when Peter the Great, Emperor of Russia, visited England,

VOL. III.

he was invited to his table, and became both his friend and his guest. He was also highly respected and esteemed by Newton; and he most ably repelled the attacks of Hooke and

Souciet on that illustrious philosopher, who speaks of him, in the preface to a paper of Halley's, upon the subject of gunnery, as virum in omni genere doctrinæ eruditissimum."

THE proper name of this "prince and Mæcenas of botany," as he is called by several writers, was Sherwood, and he was born at Bushby, in Leicestershire, in 1659. He received his education at Merchant Tailor's School, and at the University of Oxford, where he became a fellow of St. John's College, and graduated B.A., in 1683. About this time, being appointed travelling tutor to Charles (afterwards Viscount) Townshend, he accompanied that nobleman on a continental tour, which he subsequently repeated with his second pupil, Lord Howland (afterwards second Duke of Bedford). Holland, France, Switzerland, and Italy, were the scene of his travels, and, in each of these countries, he not only carried on his botanical researches with ardour and ability, but formed an acquaintance with the most eminent foreigners of science, among whom were Boerhaave, Vaillant, Tournefort, Hermann, and Micheli. In his own country he had already gained the friendship of the illustrious Ray, having, previously to his departure from England, enriched the publications of that celebrated botanist by some valuable additions, and to whose Sylloge Stirpium Europcarum, he contributed, on his return, a catalogue of plants gathered in the neighbourhood of Geneva, In the years 1686, 1687, and 1688, he attended the lectures of Tournefort, at Paris, as appears from the preface to a work, entitled Schola Botanica, published anonymously, at Amsterdam, in 1689, but of which Ray appears to have been the author. It contained a systematic catalogue of the plants in the royal garden at Paris, and was reprinted in 1691, and 1699.

Soon after his arrival in England from his last tour, the subject of our memoir became one of the commissioners for sick and wounded seamen

at Portsmouth; and, about the year 1702, he was sent out as British consul to Smyrna. He remained in this capacity sixteen years, in the course of which he diligently studied various branches of science and literature; visited the seven churches of Asia; and communicated to the Royal Society an account of a new volcanic island, near Santorini, which rose out of the sea, on the 12th of May, 1707. Botany, however, continuing to be the favourite object of his pursuit, he purchased a villa and garden, at Sedekio, where he passed the greater portion of his time, occupied in the contemplation of plants, and in the cultivation of such as he had obtained from the neighbouring countries. In this spot, which Hasselquist, in the course of his travels, is said to have visited, with the devotion of a pilgrim, Sherard began his Herbarium, and he also made some progress in the arduous undertaking of continuing Bauhin's Pinax Botanicus. He returned home in 1718; and, after having received, at Oxford, the degree of LL.D., again repaired to the continent, where he assisted in editing, and negotiated the sale of, Vaillant's Botanicon Parisiense, to Boerhaave, and came back to England, in 1721, with the celebrated Dillenius, whom he had taken under his patronage and friendship. In 1724, he paid another visit to Boerhaave, in Germany; and, whilst pursuing his botanical researches in that country, is said to have been, "like Linnæus, in Norway, in danger of being shot for a wolf or a thief."

From the moment of his association with Dillenius, whose taste in this respect was similar with his own, Sherard renewed, with increased ardour, his investigations concerning those intricate tribes of vegetables, termed cryptogamic; and to their united la

bours is owing the cultivation which this line of botanical study has since received in England and Germany. Whilst pursuing his own researches, he was not unmindful of the labours of others; and, having acquired a tolerable fortune, was ever ready to give both money and information to those by whom they were needed. In this manner he assisted Catesby, in his Natural History of Carolina, and Dillenius in his Hortus Elthamensis; although neither works appeared until some time after his death, which took place on the 12th of August, 1728.

Dr. Sherard seems to have pursued his botanical researches out of pure love of the science, unmixed with any other ambition than that of extending its

limits, and of witnessing its improvements. At his death he left £3,000 to found and support a botanical professorship at Oxford, with a proviso, for which he has been blamed, that no clergyman should be elected to the chair. He also bequeathed to the university his very valuable library, the manuscript of his Pinax, and his Herbarium, which is, perhaps, except that of Linnæus, the most ample, authentic, and valuable botanical record in the world.

The name of Sherard has been commemorated by Vaillant, in some plants referred, by Linnæus, to Verbena; and Dillenius established a Sherardia, în honour of his munificent and learned patron.

HANS, the son of Alexander Sloane, a Scotchman, who, with a colony of his countrymen, had settled, during the reign of James the First, in the north of Ireland, was born at Killaleagh, in the county of Down, on the 16th of April, 1660. He displayed, from his boyhood, a strong predilection for natural history, and adopted the medical profession principally on account of the facilities it would afford him for following his favourite pursuits. He appears to have commenced the study of physic under Dr. Strafforth, in London; whence, after having attended various lectures on botany, anatomy, and chemistry, and formed a close intimacy with Boyle and Ray, he proceeded to Paris, where he became a pupil of Du Verney and Tournefort. At the University of Montpellier, according to some writers, he took his medical degrees, while others assert that he obtained them at Orange. Be this as it may, it appears certain that he passed some time at the former place; and, while there, made a large collection of plants; in the arrangement of which, he was materially assisted by the learned Magnol.

In 1684, he returned to London, and was, soon after, elected a member of the Royal Society. In April, 1687, he

became a fellow of the College of Physicians; and, on the 12th of the following September, proceeded to the West Indies, in the capacity of physician to the Duke of Albemarle, Governor of Jamaica. Here, in about fifteen months, he made an enormous collection of plants and other objects of natural history of the former, he brought home no less than eight hundred species; "a number," says Dr. Pulteney, in his Sketches of Botany,

"

very far beyond what had been inported, by any individual in England, before."

In May, 1689, Dr. Sloane returned to London, and resumed the duties of his profession; in which he became so eminent, that, in 1694, he was chosen physician to Christ's Hospital; and it is stated, by Mr. Hutchinson, that he applied the money he received from this appointment, which he held for thirty-six years, to the relief of the poor in the hospital. In the pre

vious year, he had been appointed secretary to the Royal Society; and, having revived the publication of the Philosophical Transactions, he continued to edit them until 1712.

In 1696, he published the prodromus to his History of Jamaica plants, under the title of Catalogus Plantarum quæ in

Insulâ Jamaicâ sponte proveniunt vel vulgo coluntur, &c.; a work, of which it is impossible to speak too highly. For indefatigable labour, and accurate research, it may be pronounced unequalled, though it is an objection against the author, that he has adhered too much to popularly-received genera of plants; taking, as his guides of arrangement, habit and general resemblance, rather than the structure of the fructification. In 1701, he was created M. D. at Oxford; and he was afterwards made a member of the Royal Academy of Sciences, at Paris, and of several other foreign academies. In 1707, appeared the first volume of his great work upon Jamaica, consisting of a general account of the discovery of the West Indies, and of the island of Jamaica in particular, and dedicated to Queen Anne, in whose last illness he was one of the physicians consulted. It was entitled A Voyage to the Islands of Madeira, Barbadoes, Nevis, St. Christopher's, and Jamaica; with the Natural History of the Herbs and Trees, Four-footed Beasts, Fishes, Birds, Insects, Reptiles, &c.; to which is prefixed an introduction, wherein is an account of the inhabitants, air, water, diseases, trade, &c. of that place; with some relations concerning the neighbouring continent and islands of America, folio, with two hundred and fiftysix plates. The second volume did not appear until seventeen years afterwards, when it was published, dedicated to the king.

In 1716, Dr. Sloane was created a baronet by George the First; being. it is said, the first physician on whom that honour was conferred. During the reign of the same monarch, he was physician-general to the ariny; and, on the accession of George the Second, he was appointed the king's physician in ordinary. In 1719, he was elected president of the College of Physicians; and, on the death of Sir Isaac Newton, in 1727, he succeeded him as president of the Royal Society; to which body he presented one hundred guineas, and a bust of their founder, Charles the Second. He presided over this institution until 1740, enjoying, in the mean time, the highest reputation as a naturalist, and one scarcely inferior as a physician. In 1741, he retired to his

abode at the manor-house of Chelsea, where the infirmities of age assailed him, and he died, on the 11th of January, 1752, in the ninety-second year of his age. He had been a widower since 1724; having married, in 1695, Elizabeth. daughter of Alderman Langley, by whom he had issue one son and three daughters.

In person, Sir Hans was tall and well made; in his manners, easy, polite, and engaging; and, in his conversation, sprightly and entertaining. His charity and liberality were extensive; and, besides being governor of almost every hospital in London, he founded a dispensary for the poor; his exertions for the establishment of which, and the opposition he met with, are recorded in Dr. Garth's poem of The Dispensary. He was also, says Dr. Pulteney," zealous in promoting the colony of Georgia, in 1732; and formed, himself, the plan for bringing up the children in the Foundling Hospital, in 1739. His principal claim, however, to the gratitude of his countrymen, is the share he had in the formation of the British Museum; of which his bequest to the public, at the price of £20,000, of the whole of his collection in natural history, with his valuable library and manuscripts, &c., laid the foundation. Accordingly, parliament complying with the terms, an act was passed, in 1753, "for the purchase of the museum or collection of Sir Hans Sloane, Bart., and of the Harleian collection of manuscripts, and for procuring one general repository for the better reception and more convenient use of the said collection, and of the Cottonian library, and additions thereto." Sir Hans oc cupied the greater part of his life in amassing this splendid collection, which he took great delight in exhibiting to strangers, particularly if they were foreigners.

He wrote several papers in the Philosophical Transactions, besides his Natural History of Jamaica, which Dr. Freind calls "an elaborate work, greatly tending to the honour of our country, and the enriching of the Materia Medica." It is, however, to be regretted, that a man of such practical benevolence as Sir Hans Sloane, should, in this work, which redounds so highly to his honour as a man of science, have ex