the aberration of the celestial bodies. His theory upon this subject was published in the Philosophical Transactions for 1728, and extended the fame of the author all over Europe, as an accurate observer, and profound philosopher. A very brief account of it must suffice here. Having determined the law of the variation in the motion of the fixed stars, Dr. Bradley was at first inclined to attribute it to the nutation of the earth's axis; but immediately abandoned this hypothesis, upon seeing that stars which, from the equality of their polar distances, ought to have had the same nutation, sustained very different changes of declination. He had been some time making observations with Graham's instrument, without the desired effect, when the discovery of Roemer, concerning the successive propagation of light, came into his mind. He then instantly saw, that all the phenomena which he had observed, might be occasioned by the motion of the earth in its orbit, combined with the successive propagation of light.

In 1730, he was appointed to succeed Mr.Whiteside, as lecturer in astronomy and experimental philosophy, in the University of Oxford; and, in 1737, he published his Observations on the Comet which appeared at the beginning of that year. Halley, who was the astronomer-royal at Greenwich, and now growing old, offered to resign his situation in favour of the subject of our memoir; but his death took place before the arrangement could be effected. On that event, however, which occurred in February, 1742, Bradley was appointed his successor, through the influence of the Earl of Macclesfield, and in the same year he was created D. D. by the University of Oxford. He had not long entered upon the duties of his new appointment, before he made such observations as enabled him to arrive at his important discovery of the nutation of the earth's axis. This he communicated to the Royal Society, in 1745, in a letter addressed to the Earl of Macclesfield, which is said to be equally remarkable for its philosophical precision, and for the simplicity and modesty with which it is written. His discovery was rewarded by the Royal Society's annual gold medal.

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He now turned his attention towards the improvement of the instruments in the Royal Observatory at Greenwich, it being his opinion that, "as we advance in the means of making more nice inquiries, new points generally offer themselves, that demand our attention." In consequence of his representation, a sum of £1,000 was granted, in 1748, to be expended on astronomical apparatus, which, under his superintendence, with the assistance of Mr. John Bird, and Mr. Graham, soon became one of the most perfect in Europe. Among other instruments which were set up at the observatory, was the new naval quadrant, of which he afterwards made such important use. In 1748, he was chosen a foreign member of the Royal Academy of Sciences at Paris; and, about the same time, he became entitled to Bishop Crew's benefaction of £30 a-year to the lecturer in experimental philosophy at Oxford. 1751, he was offered the valuable living of Greenwich, but he conscientiously declined it; alleging, that the duty of a pastor was incompatible with his other studies and engagements. The king was so pleased with this instance of his integrity, that he immediately granted him a pension of £250 a-year, which has since been regularly paid to the astronomer-royal. In 1752, he was elected one of the council of the Royal Society; in 1754, a member of the Academy of Sciences at Petersburgh, by diploma, from the whole body; and, in 1757, admitted a member of the Academy of Sciences at Bologna. He was subsequently chosen into the Prussian Academy of Science and Belles Lettres at Berlin. He pursued his studies with such unabated vigour, that, towards the close of his life, he began to fear that he should survive his rational faculties. He died, however, without having experienced this calamity, on the 13th of July, 1762, at Chalford, in Gloucestershire. He was a widower at the time of his death, having left one daughter by his wife, whom he married in 1744.

"The public character of Dr. Bradley," says one of his biographers, " as a man of science and discernment, is well established by his works. His private character was in every respect estimable. Temperate in his enjoy

became known, the illustrious Linnæus not only corresponded with him, but completed the general index to his works, according to Edwards's system. The Copleian medal was awarded to him by the Royal Society, in 1750, for his History of Birds; and, in 1757, he was elected a member of that body. He was also aggregated to several of the learned societies in different parts of Europe. In 1769, having previously disposed of his immense collection of drawings to Lord Bute, he resigned his office of librarian at the College of Physicians, and retired to Plaistow, in Essex. His last publication, which consisted of miscellaneous pieces, chiefly collected from the prefaces and introductions to

his books, appeared in 1770, under the title of Essays. During the latter part of his life, he was severely afflicted, having, at the same time, to endure the agonies of the stone, and of a cancer, which deprived him of the sight of one eye. He bore, with great fortitude and resignation, his sufferings, which were terminated by his death, in July, 1773. Books and conversation formed his chief amusement in his later years. In mixed company, his diffidence and humility prevented him from shining, but with his intimate friends few could be more entertaining or communicative. Besides the works before-mentioned, he contributed several papers to the Philosophical Transactions.

THIS celebrated mechanic was the son of a carpenter, at Foulby, near Pontefract, in Yorkshire, where he was born, in the year 1693. He received but a very limited education, and as soon as he was able, assisted his father in his business, which comprehended the occasional survey of land, and repairing of clocks and watches. For this latter department he evinced a particular predilection; and, as early as his sixth year, when he lay sick of the small-pox, is said to have amused himself in bed, for hours, by watching the movement of a small time-piece, which was placed open upon his pillow. In 1700, he removed, with his father, to Barrow, near Barton-upon-Humber, in Lincolnshire, where his thirst after information developed itself in a very striking manner. He frequently sat up whole nights, employed in writing or drawing; and having been lent a manuscript copy of Professor Saunderson's lectures, he carefully and neatly transcribed them, together with all the diagrams. With a mind so inquiring, and a genius totally unfettered, Harrison found his energies rather invigorated, than weakened, by the want of education. In 1726, he had attained to such skill in horology, as to be able to construct two wooden clocks, with an escapement and compound pendulum of his own invention: they surpassed

everything of the kind then made, and scarcely erred a second in a month.

This success probably induced Mr. Harrison to attempt to gain the reward of £20,000, which government were empowered, by an act of parliament, passed in the fourteenth of Queen Anne, to offer for discovering the longitude. He, accordingly, made drawings of a machine he had planned for this purpose; and, in 1728, came to London, and presented them to Dr. Halley, then astronomer-royal. Dr. Halley referred him to Mr. George Graham, by whose advice he returned home, completed, and made trial of, his machine, during very bad weather, upon the river Humber, and, in 1735, came back with it to the metropolis. It was examined by the Royal Society, who subscribed a favourable certificate of its properties; in consequence of which, it was put on board of a man-of-war, in 1736, and sent, with the maker, on a voyage to Lisbon and back, to make trial of its exactness. He was enabled to correct the deadreckoning nearly a degree and a half, and received, in the following year, a reward of £500 from the commissioners of the longitude, who recommended him to proceed with the improvement of his time-piece. He completed a second in 1739, of simpler construction and greater accuracy: qualities which were still more

predominant in his third machine, which erred only three or four seconds in a week. It procured him the Royal Society's annual gold medal, and he considered it the ne plus ultra of his art; but further experiments convinced him that it was possible to achieve still greater perfection. This he attempted in a fourth time-keeper, which he finished in 1759, in the form of a pocket-watch, about six inches in diameter. A trial of its accuracy was made in two voyages, which his son took with it, to the West Indies; and as it corrected, in both voyages, the longitude within the limits required by Queen Anne's act, Mr. Harrison applied to parliament for the reward of £20,000. Half of it was paid to him in 1765, and he subsequently received the remainder, but not without some trouble and repeated applications. "This delay," says his biographer, "in issuing to him his full reward, originated in the anxiety of the commissioners of the longitude to do justice to the public, at the same time that they encouraged merit in an individual; by obtaining from the inventor a full and clear discovery of the principles on which his time-piece was constructed, and by having it satisfactorily ascertained that they were such as rendered it of general use, by enabling other artificers, with reasonable skill, in reasonable time, and at a reasonable expense, to make similar machines."

Mr. Harrison received altogether the sum of £24,000 from the board of longitude, besides several hundred pounds from the East India Company. The

accuracy of his fourth machine, which is emphatically called Harrison's timekeeper, was further proved by a duplicate of it, constructed by Mr. Kendal, which, during a three years' circumnavigation of the globe, by Captain Cook, answered as well as the original. The subject of our memoir employed the latter part of his life in making a fifth time-keeper, which was tried for ten weeks, at the King's Observatory at Richmond, in 1772, and found to err only four seconds and a half in that time. Its ingenious constructor died at London, in 1776, in the eighty-second year of his age.

Mr. Harrison never became a man of the world, and possessed little knowledge of other subjects besides mechanics, on which he conversed with clearness, precision, and modesty. From the peculiar and uncouth phraseology, however, in his Description concerning such Mechanism as will afford a nice or true Mensuration of Time, &c., it is apparent that he found some difficulty in expressing his ideas in writing. This work includes an account of his new musical scale, or mechanical division of the octave, according to the proportion which the radius and diameter of a circle have respectively to the circumference. Mr. Harrison had a delicate musical ear, and, in his youth, was the leader of a distinguished band of church singers. Some experiments which he made on sound, and a curious monochord of his own improvement, are said to have been equally accurate with those in which he was engaged for the mensuration of time.

FRANCIS HUTCHESON, son of a dissenting minister, was born in the north of Ireland, in 1694. After a previous course of education, he, in 1710, entered a student of the University of Glasgow, where he studied the classics, philosophy, and divinity, for six years. On his return to his native country, he was licensed to preach among the dissenters, and was about to accept the pastorship of a congregation, when he received an invitation to set up an academy at Dublin. Here his accomplish

ments soon procured him the acquaintance and friendship of many persons distinguished for their rank and learning, and, in particular, of Lord Molesworth. This nobleman is said to have assisted him in his Inquiry into the Ideas of Beauty and Virtue, which appeared in 1725, without the author's name. The work created a great sensation in the literary world, and Lord Granville, then lord-lieutenant, was so struck with its merits, that he sent to his bookseller to inquire who the writer

was, and left a letter to be conveyed to him. Mr. Hutcheson was shortly afterwards introduced to his lordship, who, during the whole period of his viceroyalty, treated him with particular marks of familiarity and esteem. Either the talents, however, or the reputation of the subject of our memoir, raised him enemies as well as friends, and he was twice prosecuted in the Archiepiscopal court, for undertaking the instruction of youth, without having subscribed to the ecclesiastical canons, or obtained a license from the bishop. Both attempts failed, in consequence of the friendship of Archbishop King towards Hutcheson. He was also much esteemed by the primate, Dr. Boulter, from whom he procured the donation of a yearly fund, for an exhibitioner, to be educated to any of the learned professions at Glasgow.

In 1728, he published his Treatise of the Passions, &c., a work which was scarcely less admired than his former one, even by those who were opposed to his philosophy. In the same year, some letters, signed Philaretus, appeared in The London Journal, calling in question some parts of the doctrine of his Inquiry, &c., which, together with our author's answers, were afterwards published in a separate pamphlet. In 1729, he received an invitation to fill the chair of moral philosophy in the University of Glasgow, which he accepted, and, about the same time, was admitted to the degree of LL.D. Had he remained in Ireland, it is probable that his friends might have obtained him preferment, as they had neither want of inclination nor power to serve him; but “ he had private reasons," says his biographer, Dr. Leechman, "which determined him neither to seek promotion, nor to encourage the most probable schemes proposed to him for obtaining it."

As a lecturer, Dr. Hutcheson amply sustained his own reputation, and realized the expectations that had been formed of him. Pupils flocked to him

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from all parts of England and Ireland; and the credit of the university was greatly increased by the admirable manner in which he performed his duties. He died, universally respected and lamented, in 1747, in the fifty-third year of his age.

One of Dr. Hutcheson's most celebrated works did not appear till 1775, when his son, Dr. Francis Hutcheson, | published, in two volumes, quarto, his System of Moral Philosophy. The work is divided into three parts: in the first of which, the author endeavours to develope the several principles of the human mind, as united in a moral constitution, and from thence to point out the origin of our ideas of moral good and evil, and of our sense of duty, or moral obligation. This leads him to the inquiry of what must be the supreme happiness of mankind; and, in the second and third part, he goes on to deduce the particular laws of nature, or rules necessary to be observed for promoting the general good, in our common intercourse with one another as members of society. His leading philosophical doctrine is, that we have a moral sense implanted in our natures, or an instinct, like that of selfpreservation, which, independently of any arguments taken from the reasonableness and advantages of any action, leads us to perform it ourselves, or to approve it when performed by others.

The various abilities and talents of Dr. Hutcheson were united with the highest integrity of mind, and the most amiable and engaging disposition. His conversation has been called, by one of his biographers, a school of virtue to those who had the happiness to enjoy it. "A remarkable vivacity," adds the same authority, "of thought and expression, a perpetual flow of cheerfulness and good-will, and a visible air of inward happiness, made him the life and genius of society, and spread an enlivening influence everywhere around him. "

self-taught mathematician, is supposed to have been a native of Argyleshire,

known. He is said to have reached an advanced age in 1760, and would seem