observations upon it, lest he should cast a stain upon his nobility!

Fickle in purpose, and discontented with Denmark, Tycho set out in search of a more suitable residence; but when the king heard of his plans, he resolved to detain him by acts of kindness and liberality. He was therefore presented to the canonry of Roschild, with an annual income of 2,000 crowns, and an additional pension of 1,000; and the island of Huen was offered to him as the site of an observatory, to be furnished with instruments of his own choice. The generous offer was instantly accepted. The celebrated observatory of Uraniburg, the City of the Heavens, was completed at the expense of £20,000, and from its hallowed towers Tycho continued for 21 years to enrich astronomy with the most valuable observations. From every kingdom in Europe admiring disciples repaired to this sanctuary of the sciences, to acquire a knowledge of the heavens, and kings and princes felt themselves honoured as the guests of the great astronomer.

Among the princes who visited Uraniburg, we are proud to enumerate James VI. of Scotland. In 1590, during his visit to Denmark to celebrate his marriage with the Princess Anne, he spent eight days with Tycho, accompanied with his counsellors and a large suite of nobility. He studied the construction and use of the astronomical instruments; he inspected the casts and pictures in the museum, and when he found among them the portrait of his own distinguished preceptor, George Buchanan, he could not refrain from the strongest expressions of delight. Upon quitting Uraniburg, James not only presented Tycho with a magnificent donation, but afterwards gave him his royal license to publish his works in England.

The equanimity of Tycho was not disturbed by these marks of respect and admiration; but while they animated his zeal and stimulated his labours, they were destined to be the instrument of his ruin. By the death of Frederick II. in 1588, Tycho lost his most valued friend; and though his son and

successor, Christian IV., visited Uraniburg, and seemed to take an interest in astronomy, his wishes to foster it, if he did cherish them, must have been overruled by the influence of his counsellors. The parasites of royalty found themselves eclipsed by the brightness of Tycho's reputation. They envied the munificent provision which Frederick had made for him; and, instigated by a physician who was jealous of his reputation as a successful practitioner in medicine, they succeeded in exciting against Tycho the hostility of the court. Walchendorf, the president of the council, was the tool of his enemies, and on the ground of an exhausted treasury, and the inutility of the studies of Tycho, he was deprived of his canonry, his pension, and his Norwegian estate.

Thus, stripped of his income, and degraded from his office, Tycho, with his wife and family, sought for shelter in a foreign land. His friend, Count Henry Rantzau, offered him the hospitality of his castle of Wandesberg, near Hamburg, and, having embarked his family and his instruments on board a small vessel, the exiled patriarch left his ungrateful country never to return. In the castle of Wandesberg he enjoyed the kindness and conversation of his accomplished host, by whom he was introduced to the emperor Rodolph, who, to a love of science, added a passion for alchemy and astrology. The reputation of Tycho having already reached the imperial ear, the recommendation of Rantzau was hardly necessary to insure him his warmest friendship. On the invitation of the emperor he repaired in 1599 to Prague, where he met with the kindest reception. A pension of 3,000 crowns was immediately settled upon him, and a commodious observatory erected for his use. Here he renewed with delight his interrupted labours, and rejoiced in the resting-place which he had so unexpectedly found for his approaching infirmities. These prospects of returning prosperity were enhanced by the pleasure of receiving into his house two such pupils as Kepler and Longomontanus; but the fallacy of human anticipation was here, as in so many

other cases, strikingly displayed. His toils and his disappointment had made severe inroads upon his constitution. Though surrounded with affectionate friends and admiring disciples, he was still an exile in a foreign land. Though his country had been base in its ingratitude, it was yet the land which he loved the scene of his earliest affections-the theatre of his scientific glory; these feelings constantly preyed upon his mind, and his unsettled spirit was ever hovering among his native mountains. In this condition he was attacked with a disease of the most painful kind, and though the paroxysms of its agonies had lengthened intermissions, yet he saw that death was approaching him. He implored his pupils to persevere in their scientific labours. He conversed with Kepler on some of the profoundest questions in astronomy, and with these secular occupations he mingled frequent acts of piety and devotion. In this happy frame of mind he expired without pain on the 24th October, 1601, at the age of 55, the unquestionable victim of the Councils of Christian IV.

Among the great discoveries of Tycho, his improvements of the lunar theory are perhaps the most important. He discovered the inequality called the Variation, amounting to 37 minutes, and depending on the distance of the moon from the sun. He discovered also the annual inequality of the moon depending on the position of the earth in its orbit, and affecting also the place of her apogee and node. He determined likewise the greatest and least inclination of the moon's orbit, and he represented this variation by the motion of the pole of the orbit in a small circle. Tycho had the merit, too, of being the first to correct, by the refraction of the atmosphere, the apparent places of the heavenly bodies; but what is very unaccountable, he made the refraction, which he found to be 34° in the horizon, to vanish at 45°, and he maintained that the light of the moon and stars was refracted differently by the atmosphere! By his observations on the comet of 1577 he proved that it was three times as distant as the moon, and

that since these bodies move in all directions, the doctrine of solid orbs could not be true. By means of large and accurately divided instruments, some of which were altitude and azimuth ones, having their divided circles six and nine feet in diameter, and others mural quadrants, sextants, and armillary spheres, he made a vast collection of observations, which led Kepler to the discovery of his celebrated laws, and formed the basis of the Rudolphine Tables. But the most laborious of his undertakings was his catalogue of 777 stars, for the epoch of 1600 A.D., a catalogue afterwards enlarged by Kepler from Tycho's observations, and published in 1627. The skill of Tycho in observing phenomena surpassed his genius for discovering their cause, and it was perhaps from his veneration for the scriptures, rather than from the vanity of giving his name to a new system, that he rejected the Copernican hypothesis. In the system which bears his name the earth is stationary in the centre of the universe, while the sun, with all the other planets and comets revolving around him, performs his daily revolution about the earth.

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BACON, FRANCIS, LORD VERULAM.-1561-1626.* Francis Bacon was born in London in 1561. In his thirteenth year he entered the university of Cambridge, where, as we are told, he made astonishing progress in all the sciences there taught, and, before the completion of his sixteenth year, wrote against the Aristotelian philosophy, which, in his estimation, was rather calculated to perpetuate disputes than to enlighten the mind. From Cambridge he went to Paris, in the suite of Sir Amos Paulet, and was by him sent to England on an important mission, which he discharged to the satisfaction of Elizabeth, and afterwards returned to France, visiting several of its provinces, and making a close study of its manners and laws, as is proved by his book-entitled, "Of the State of Europe"-published when he was only nineteen years of age. On his return to England, which was hastened by the death of his father, he devoted himself to the study of the law, and that with so much success as to gain for him the appointment of counsel extraordinary to the queen, in 1588, when he was only 27. In 1593, he entered parliament as member for the county of Middlesex. In the quarrel between Sir Robert Cecil and the Earl of Essex, both of whom were his patrons, he sided with Cecil, though under a heavy obligation to Essex, who had made him a present of an estate; and when Essex fell into disgrace, not merely did he abandon him, but, without being obliged to do so, took part against him on his trial, in 1600, to the disgust of the public and the displeasure of the queen. Bacon remained at court, the object of hatred to one party, and of jealousy to the other. The servility which he manifested towards the end of Elizabeth's reign, and which became

*The matter of this sketch was derived from the "Of the proficience and advancement of learning, by Francis, Lord Verulam, edited by B. Montagu, Esquire," 1840; "The Novum Organum," or true suggestions for the interpre tation of Nature, by Francis, Lord Verulam, 1850, London, William Pickering : and from Encyclopædias.