Hueen, in the Sound, together with a pension of five hundred crowns, a lordship in Norway, and an ecclesiastical benefice, which brought him two thousand crowns more, in order that with these revenues, added to those of his original estates, he might be enabled to prosecute his celestial observations on the grandest scale. In this island, accordingly, Brahe now took up his abode, and soon erected on it a splendid observatory, provided with all the best instruments known in that age. He spent, he says, a hundred thousand crowns of his own money upon its completion, in addition to the produce of his grants from the king. Here he resided for seventeen years, during the whole of which time he continued to devote himself, with unabated zeal, to his scientific pursuits. But such was now his fame, that, even in this retirement, beside being surrounded, as before, by pupils who crowded to profit by his instructions, he was sought out by many visitors, both from his own and foreign countries. Among other persons of distinction who came to see him, was our James I., then king of Scotland, who passed a week with him in the year 1590; but if the story that is told be true, this visit was anything rather than a fortunate incident for Brahe. Some years afterwards, it is said, his protector, Frederick II., being dead, he was visited one day by the young King Christian IV., accompanied by his chief minister, Walckendorf; and it so happened that this latter personage, who was very sensitive and choleric, was barked at, as he approached the house, by two dogs belonging to the astronomer, at which he chose to be so much offended, that he went up to the animals and beat them severely. The dogs had been presented to Brahe by the Scottish monarch; and irritated at seeing them ill-treated, he interfered to prevent the enraged senator from continuing his chastisement. This gave rise to some high words between the two,

and the result was a quarrel, which Walckendorf, at least, never forgot. From that day, Brahe's ruin was resolved upon by his powerful enemy. A commission was soon after appointed to report upon the public utility of his establishment; and upon this compliant body declaring that they saw nothing in his splendid observatory but a source of useless expense to the state, a decree was passed, recalling all the grants he had received from the former king, and dispossessing him of his island. On this, Brahe determined to bid adieu for ever to his ungrateful country; and, taking with him all his instruments, he retired to Germany. About two years afterwards, however, he was invited to take up his residence at Prague, by the Emperor, Rodolph II.; and by this prince, who was warmly attached to science, he was provided with a second asylum, almost as splendid as that which he had enjoyed in his native country. But he lived only a very short time after this, having died in 1601, in the fifty-fifth year of his age. Tycho Brahe, as most of our readers are probably aware, was the inventor, or reviver, of a peculiar scheme of the universe, according to which the earth is conceived to be immoveable in the centre of the system, the sun to revolve round it, and the other planets round the sun. It is unnecessary to say that this hypothesis has been long exploded. Indeed, even at the time when it was proposed by its author, it was, although supported by him with much ingenuity, a most unphilosophical retrogression from the true system previously established by Copernicus. But although Brahe, it thus appears, has no very high claims upon our admiration as a theorist, he undoubtedly did much in another way to promote the improvement of astronomy. His extraordinary devotion to the science, of itself, operated as inspiration upon many of the other ardent, minds of the time. But it was

by the great number and comparative exactness of his observations, far surpassing anything that had been attained by his predecessors, that he chiefly contributed to the progress of astronomy. No other but one in his circumstances could have commanded either the leisure or the pecuniary means necessary for the making of these observations, which, besides having occupied many years, owed much of their superior accuracy to the excellence and consequent costliness of the instruments which Brahe employed. Here, therefore, was a case in which science was indebted to the wealth of one of its cultivators for services which no zeal or talents could have otherwise enabled him to render.

Another man of fortune, to whom both science and the arts are under considerable obligations, is the German mathematician, TSCHIRNHAUSEN, celebrated for the discovery of the peculiar curve called, after him, Tschirnhausen's Caustics. He was born in 1651, at the seat of his ancestors, in Upper Lusatia; and although, after receiving an excellent education, he entered the army at an early age, he very soon quitted the profession of a soldier, and set out on his travels through England, Italy, and France, He spent several years in traversing these countries, embracing every opportunity of obtaining a knowledge of their arts, manufactures, and productions, and seeking the acquaintance of the learned men of the time, wherever he went. On returning home, he took up his residence on his estate, the revenues of which were ample; and the remainder of his life was given to scientific speculations and experiments. The science of optics was that to which he was chiefly attached; and it was while making some experiments with reflecting mirrors, that he discovered his Caustics, which are curves formed by light reflected in certain circumstances, and are so called from the

Greek word for a burning-glass. They possess some remarkable geometrical properties*. When Tschirnhausen announced this discovery to the French Academy of Sciences, he was only in his thirty-first year; but he was immediately admitted a member of the Academy by order of the King, Louis XIV. In order to have the aid of proper instruments in the prosecution of his researches, he afterwards established three glass-houses in his native district; at which he employed all the resources of his ingenuity in endeavouring to fabricate burning-glasses of greater size and power than any which had ever been elsewhere produced. In 1687 he had made a concave reflecting mirror of copper, of the diameter of four feet and a half, which consumed wood and fused metals at twelve feet distance, in a few seconds; but although these effects greatly surpassed anything of the same kind that had been accomplished in modern times, he found the inconvenience of operating by reflection so great, that he determined to persevere in his attempts to obtain, if possible, a lens of equal magnitude. He did not exactly attain this object; for the largest lens he succeeded in producing had only a diameter of three feet. But when it is added that nobody but himself had ever before made one of more than four or five inches diameter, his success will probably be deemed sufficiently extraordinary. The method he employed in fabricating this immense glass is not known. It was convex on both sides, and weighed a hundred and sixty pounds. Although somewhat less in size, its effects greatly exceeded those of the

* In an article of some length upon Tschirnhausen, in the Biographie Universelle, the writer, M. Gley, by a strange blunder, mistakes these curves for actual burning-glasses; and describes, with great minuteness, their wonderful powers in kindling and consuming, or melting, wood, iron, tiles, slates, and earthen-ware! -Vid. Biog. Univ. xlvii. 3.

reflector he had formerly used. This lens was purchased from Tschirnhausen by the Duke of Orleans, who afterwards made a present of it to the Academy of Sciences. Tschirnhausen deserves, also, to be remembered as the founder of the celebrated porcelain manufactory of Dresden. Before his time, it was supposed that the Chinese employed for their porcelain a peculiar earth, only found in their own country; but he discovered that the same species of ware could be manufactured from a compound of different sorts of earth, which might be obtained in Europe as well as in China. This eminent benefactor to the arts, who, besides his contributions to the Transactions of the French Academy, was also the author of two separate works, the first, entitled The Medicine of the Body, the latter, The Medicine of the Mind, being, in fact, a system of the art of reasoning,-died in 1708.

But, perhaps, the best example we can adduce of the manner in which wealth may be made subservient by its possessor, not only to the acquisition of knowledge, but also to its diffusion and improvement, is that of our celebrated countryman the Honourable ROBERT BOYLE. Boyle was born at Lismore, in Ireland, in 1627, and was the seventh and youngest son of Richard, the first Earl of Cork, commonly called the Great Earl. The first advantage which he derived from the wealth and station of his father, was an excellent education. After having enjoyed the instructions of a domestic tutor, he was sent, at an early age, to Eton. But his inclination, from the first, seems to have led him to the study of things, rather than of words. He remained at Eton only four years, "in the last of which," according to his own statement, in an account which he has given us of his early life, "he forgot much of that Latin he had got, for he was so addicted to more solid parts

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