Galileo viewed all these circumstances in a different light. He resolved to compose a work in which the Copernican system should be demonstrated; but he had not the courage to do this in a direct and open manner. He adopted the plan of discussing the subject in a dialogue between three speakers, in the hope of eluding by this artifice the censure of the church. This work was completed in 1630, but, owing to some difficulties in obtaining a license to print it, it was not published till 1632.

In obtaining this license, Galileo exhibited considerable address, and his memory has not escaped from the imputation of having acted unfairly, and of having involved his personal friends in the consequences of his imprudence.

The situation of master of the palace was, fortunately for Galileo's designs, filled by Nicolo Riccardi, a friend and pupil of his own. This officer was a sort of censor of new publications, and when he was applied to on the subject of printing his work, Galileo soon found that attempts had previously been made to thwart his views. He instantly set off for Rome, and had an interview with his friend, who was in every respect anxious to oblige him. Riccardi examined the manuscript, pointed out some incautious expressions which he considered it necessary to erase, and returned it with his written approbation, on the understanding that the alterations he suggested would be made. Dreading to remain in Rome during the unhealthy season, which was fast approaching, Galileo returned to Florence, with the intention of completing the index and dedication, and of sending the MS. to Rome, to be printed under the care of Prince Cesi. The death of that distinguished individual, in August 1630, frustrated Galileo's plan, and he applied for leave to have the book printed in Florence. Riccardi was at first desirous to examine the MS. again, but, after inspecting only the beginning and the end of it, he gave Galileo leave to print it wherever he chose, providing it bore the license of the Inquisitor-General of Florence, and one or two other persons whom he named.

Having overcome all these difficulties, Galileo's work was published in 1632, under the title of "The System of the World of Galileo Galilei, &c., in which, in four dialogues concerning the two principal systems of the world—the Ptolemaic and the Copernican—he discusses, indeterminately and firmly, the arguments proposed on both sides." It is dedicated to Ferdinand, Grand Duke of Tuscany, and is prefaced by an "Address to the prudent reader," which is itself characterised by the utmost imprudence. He refers to the decree of the Inquisition in the most insulting and ironical language. He attributes it to passion and to ignorance, not by direct assertion, but by insinuations ascribed to others; and he announces his intention to defend the Copernican system, as a pure mathematical hypothesis, and not as an opinion having an advantage over that of the stability of the earth absolutely. The dialogue is conducted by three persons, Salviati, Sagredo, and Simplicio. Salviati, who is the true philosopher in the dialogue, was the real name of a nobleman whom we have already had occasion to mention. Sagredo, the name of another noble friend of Galileo's, performs a secondary part under Salviati. He proposes doubts, suggests difficulties, and enlivens the gravity of the dialogue with his wit and pleasantry. Simplicio is a resolute follower of Ptolemy and Aristotle, and, with a proper degree of candour and modesty, he brings forward all the common arguments in favour of the Ptolemaic system. Between the wit of Sagredo, and the powerful philosophy of Salviati, the peripatetic sage is baffled in every discussion; and there can be no doubt that Galileo aimed a more fatal blow at the Ptolemaic system by this mode of discussing it, than if he had endeavoured to overturn it by direct arguments.

The influence of this work on the public mind was such as might have been anticipated. The obnoxious doctrines which it upheld were eagerly received, and widely disseminated; and the church of Rome became sensible of the shock which was thus given to its intellectual supremacy. Pope Urban VIII., attached though he had been to Galileo, never once hesitated respecting the line of conduct which he felt himself bound to pursue. His mind was, nevertheless, agitated with conflicting sentiments. He entertained a sincere affection for science and literature, and yet he was placed in the position of their enemy. He had been the personal friend of Galileo, and yet his duty compelled him to become his accuser. Embarrassing as these feelings were, other considerations contributed to soothe him. He had, in his capacity of a Cardinal, opposed the first persecution of Galileo. He had, since his elevation to the pontificate, traced an open path for the march of Galileo's discoveries; and he had finally endeavoured to bind the recusant philosopher by the chains of kindness and gratitude. All these means, however, had proved abortive, and he was now called upon to support the doctrine which he had subscribed, and administer the law of which he was the guardian.

It has been supposed, without any satisfactory evidence, that Urban may have been influenced by less creditable motives. Salviati and Sagredo being well-known personages, it was inferred that Simplicio must also have a representative. The enemies of Galileo are said to have convinced his Holiness that Simplicio was intended as a portraiture of himself; and this opinion received some probability from the fact, that the peripatetic disputant had employed many of the arguments which Urban had himself used in his discussions with Galileo. The latest biographer of Galileo[33] regards this motive as necessary to account for "the otherwise inexplicable change which took place in the conduct of Urban to his old friend;"—but we cannot admit the truth of this supposition. The church had been placed in hostility to a powerful and liberal party, which was adverse to its interests. The dogmas of the Catholic faith had been brought into direct collision with the deductions of science. The leader of the philosophic band had broken the most solemn armistice with the Inquisition: he had renounced the ties of gratitude which bound him to the Pontiff; and Urban was thus compelled to entrench himself in a position to which he had been driven by his opponents.

[33] Library of Useful Knowledge, Life of Galileo, chap. viii.

The design of summoning Galileo before the Inquisition, seems to have been formed almost immediately after the publication of his book; for even in August 1632, the preliminary proceedings had reached the ears of the Grand Duke Ferdinand. The Tuscan ambassador at Rome was speedily acquainted with the dissatisfaction which his Sovereign felt at these proceedings; and he was instructed to forward to Florence a written statement of the charges against Galileo, in order to enable him to prepare for his defence. Although this request was denied, Ferdinand again interposed, and transmitted a letter to his ambassador, recommending the admission of Campanella and Castelli into the congregation of ecclesiastics by whom Galileo was to be judged. Circumstances, however, rendered it prudent to withhold this letter. Castelli was sent away from Rome, and Scipio Chiaramonte, a bigotted ecclesiastic, was summoned from Pisa to complete the number of the judges.

It appears from a despatch of the Tuscan minister, that Ferdinand was enraged at the transaction; and he instructed his ambassador, Niccolini, to make the strongest representations to the Pope. Niccolini had several interviews with his Holiness; but all his expostulations were fruitless. He found Urban highly incensed against Galileo; and his Holiness begged Niccolini to advise the Archduke not to interfere any farther, as he would not "get through it with honour." On the 15th of September the Pope caused it to be intimated to Niccolini, as a mark of his especial esteem for the Grand Duke, that he was obliged to refer the work to the Inquisition; but both the prince and his ambassador were declared liable to the usual censures if they divulged the secret.

From the measures which this tribunal had formerly pursued, it was not difficult to foresee the result of their present deliberations. They summoned Galileo to appear before them at Rome, to answer in person the charges under which he lay. The Tuscan ambassador expostulated warmly with the court of Rome on the inhumanity of this proceeding. He urged his advanced age, his infirm health, the discomforts of the journey, and the miseries of the quarantine,[34] as motives for reconsidering their decision: But the Pope was inexorable, and though it was agreed to relax the quarantine as much as possible in his favour, yet it was declared indispensable that he should appear in person before the Inquisition.

[34] The communication between Florence and Rome was at this time interrupted by a contagious disease which had broken out in Tuscany.

Worn out with age and infirmities, and exhausted with the fatigues of his journey, Galileo arrived at Rome on the 14th of February, 1633. The Tuscan ambassador announced his arrival in an official form to the commissary of the holy office, and Galileo awaited in calm dignity the approach of his trial. Among those who proffered their advice in this distressing emergency, we must enumerate the Cardinal Barberino, the Pope's nephew, who, though he may have felt the necessity of an interference on the part of the church, was yet desirous that it should be effected with the least injury to Galileo and to science. He accordingly visited Galileo, and advised him to remain as much at home as possible, to keep aloof from general society, and to see only his most intimate friends. The same advice was given from different quarters; and Galileo, feeling its propriety, remained in strict seclusion in the palace of the Tuscan ambassador.

During the whole of the trial which had now commenced, Galileo was treated with the most marked indulgence. Abhorring, as we must do, the principles and practice of this odious tribunal, and reprobating its interference with the cautious deductions of science, we must yet admit that, on this occasion, its deliberations were not dictated by passion, nor its power directed by vengeance. Though placed at their judgment-seat as a heretic, Galileo stood there with the recognised attributes of a sage; and though an offender against the laws of which they were the guardian, yet the highest respect was yielded to his genius, and the kindest commiseration to his infirmities.

In the beginning of April, when his examination in person was to commence, it became necessary that he should be removed to the holy office; but instead of committing him, as was the practice, to solitary confinement, he was provided with apartments in the house of the fiscal of the Inquisition. His table was provided by the Tuscan ambassador, and his servant was allowed to attend him at his pleasure, and to sleep in an adjoining apartment. Even this nominal confinement, however, Galileo's high spirit was unable to brook. An attack of the disease to which he was constitutionally subject contributed to fret and irritate him, and he became impatient for a release from his anxiety as well as from his bondage. Cardinal Barberino seems to have received notice of the state of Galileo's feelings, and, with a magnanimity which posterity will ever honour, he liberated the philosopher on his own responsibility; and in ten days after his first examination, and on the last day of April, he was restored to the hospitable roof of the Tuscan ambassador.

Though this favour was granted on the condition of his remaining in strict seclusion, Galileo recovered his health, and to a certain degree his usual hilarity, amid the kind attentions of Niccolini and his family; and when the want of exercise had begun to produce symptoms of indisposition, the Tuscan minister obtained for him leave to go into the public gardens in a half-closed carriage.

After the Inquisition had examined Galileo personally, they allowed him a reasonable time for preparing his defence. He felt the difficulty of adducing any thing like a plausible justification of his conduct; and he resorted to an ingenious, though a shallow artifice, which was regarded by the court as an aggravation of the crime. After his first appearance before the Inquisition in 1616, he was publicly and falsely charged by his enemies with having then abjured his opinions; and he was taunted as a criminal who had been actually punished for his offences. As a refutation of these calumnies, Cardinal Bellarmine had given him a certificate in his own handwriting, declaring that he neither abjured his opinions, nor suffered punishment for them; and that the doctrine of the earth's motion, and the sun's stability, was only denounced to him as contrary to Scripture, and as one which could not be defended. To this certificate the Cardinal did not add, because he was not called upon to do it, that Galileo was enjoined not to teach in any manner the doctrine thus denounced; and Galileo ingeniously avails himself of this supposed omission, to account for his having, in the lapse of fourteen or sixteen years, forgotten the injunction. He assigned the same excuse for his having omitted to mention this injunction to Riccardi, and to the Inquisitor-General at Florence, when he obtained the licence to print his Dialogues. The court held the production of this certificate to be at once a proof and an aggravation of his offence, because the certificate itself declared that the obnoxious doctrines had been pronounced contrary to the Holy Scriptures.

Having duly weighed the confessions and excuses of their prisoner, and considered the general merits of the case, the Inquisition came to an agreement upon the sentence which they were to pronounce, and appointed the 22d of June as the day on which it was to be delivered. Two days previous to this, Galileo was summoned to appear at the holy office; and on the morning of the 21st, he obeyed the summons. On the 22d of June he was clothed in a penitential dress, and conducted to the convent of Minerva, where the Inquisition was assembled to give judgment. A long and elaborate sentence was pronounced, detailing the former proceedings of the Inquisition, and specifying the offences which he had committed in teaching heretical doctrines, in violating his former pledges, and in obtaining by improper means a license for the printing of his Dialogues. After an invocation of the name of our Saviour, and of the Holy Virgin, Galileo is declared to have brought himself under strong suspicions of heresy, and to have incurred all the censures and penalties which are enjoined against delinquents of this kind; but from all these consequences he is to be held absolved, provided that with a sincere heart, and a faith unfeigned, he abjures and curses the heresies he has cherished, as well as every other heresy against the Catholic church. In order that his offence might not go altogether unpunished, that he might be more cautious in future, and be a warning to others to abstain from similar delinquencies, it was also decreed that his Dialogues should be prohibited by public edict; that he himself should be condemned to the prison of the Inquisition during their pleasure, and that, in the course of the next three years, he should recite once a week the seven penitential psalms.

The ceremony of Galileo's abjuration was one of exciting interest, and of awful formality. Clothed in the sackcloth of a repentant criminal, the venerable sage fell upon his knees before the assembled Cardinals; and laying his hands upon the Holy Evangelists, he invoked the Divine aid in abjuring and detesting, and vowing never again to teach, the doctrine of the earth's motion, and of the sun's stability. He pledged himself that he would never again, either in words or in writing, propagate such heresies; and he swore that he would fulfil and observe the penances which had been inflicted upon him.[35] At the conclusion of this ceremony, in which he recited his abjuration word for word, and then signed it, he was conveyed, in conformity with his sentence, to the prison of the Inquisition.

[35] It has been said, but upon what authority we cannot state, that when Galileo rose from his knees, he stamped on the ground, and said in a whisper to one of his friends, "E pur si muove." "It does move, though."—Life of Galileo, Lib. Useful Knowledge, part ii. p. 63.

The account which we have now given of the trial and the sentence of Galileo, is pregnant with the deepest interest and instruction. Human nature is here drawn in its darkest colouring; and in surveying the melancholy picture, it is difficult to decide whether religion or philosophy has been most degraded. While we witness the presumptuous priest pronouncing infallible the decrees of his own erring judgment, we see the high-minded philosopher abjuring the eternal and immutable truths which he had himself the glory of establishing. In the ignorance and prejudices of the age—in a too literal interpretation of the language of Scripture—in a mistaken respect for the errors that had become venerable from their antiquity—and in the peculiar position which Galileo had taken among the avowed enemies of the church, we may find the elements of an apology, poor though it be, for the conduct of the Inquisition. But what excuse can we devise for the humiliating confession and abjuration of Galileo? Why did this master-spirit of the age—this high-priest of the stars—this representative of science—this hoary sage, whose career of glory was near its consummation—why did he reject the crown of martyrdom which he had himself coveted, and which, plaited with immortal laurels, was about to descend upon his head? If, in place of disavowing the laws of Nature, and surrendering in his own person the intellectual dignity of his species, he had boldly asserted the truth of his opinions, and confided his character to posterity, and his cause to an all-ruling Providence, he would have strung up the hair-suspended sabre, and disarmed for ever the hostility which threatened to overwhelm him. The philosopher, however, was supported only by philosophy; and in the love of truth he found a miserable substitute for the hopes of the martyr. Galileo cowered under the fear of man, and his submission was the salvation of the church. The sword of the Inquisition descended on his prostrate neck; and though its stroke was not physical, yet it fell with a moral influence fatal to the character of its victim, and to the dignity of science.

In studying with attention this portion of scientific history, the reader will not fail to perceive that the Church of Rome was driven into a dilemma, from which the submission and abjuration of Galileo could alone extricate it. He who confesses a crime and denounces its atrocity, not only sanctions but inflicts the punishment which is annexed to it. Had Galileo declared his innocence, and avowed his sentiments, and had he appealed to the past conduct of the Church itself, to the acknowledged opinions of its dignitaries, and even to the acts of its pontiffs, he would have at once confounded his accusers, and escaped from their toils. After Copernicus, himself a catholic priest, had openly maintained the motion of the earth, and the stability of the sun:—after he had dedicated the work which advocated these opinions to Pope Paul III., on the express ground that the authority of the pontiff might silence the calumnies of those who attacked these opinions by arguments drawn from Scripture:—after the Cardinal Schonberg and the Bishop of Culm had urged Copernicus to publish the new doctrines;—and after the Bishop of Ermeland had erected a monument to commemorate his great discoveries;—how could the Church of Rome have appealed to its pontifical decrees as the ground of persecuting and punishing Galileo? Even in later times, the same doctrines had been propagated with entire toleration: Nay, in the very year of Galileo's first persecution, Paul Anthony Foscarinus, a learned Carmelite monk, wrote a pamphlet, in which he illustrates and defends the mobility of the earth, and endeavours to reconcile to this new doctrine the passages of Scripture which had been employed to subvert it. This very singular production was dated from the Carmelite convent at Naples; was dedicated to the very reverend Sebastian Fantoni, general of the Carmelite order; and, sanctioned by the ecclesiastical authorities, it was published at Naples in 1615, the very year of the first persecution of Galileo.

Nor was this the only defence of the Copernican system which issued from the bosom of the Church. Thomas Campanella, a Calabrian monk, published, in 1622, "An Apology for Galileo," and he even dedicates it to D. Boniface, Cardinal of Cajeta. Nay, it appears from the dedication, that he undertook the work at the command of the Cardinal, and that the examination of the question had been entrusted to the Cardinal by the Holy Senate. After an able defence of his friend, Campanella refers, at the conclusion of his apology, to the suppression of Galileo's writings, and justly observes, that the effect of such a measure would be to make them more generally read, and more highly esteemed. The boldness of the apologist, however, is wisely tempered with the humility of the ecclesiastic, and he concludes his work with the declaration, that in all his opinions, whether written or to be written, he submits himself to the opinions of the Holy Mother Church of Rome and to the judgment of his superiors.

By these proceedings of the dignitaries, as well as the clergy of the Church of Rome, which had been tolerated for more than a century, the decrees of the pontiffs against the doctrine of the earth's motion were virtually repealed; and Galileo might have pleaded them with success in arrest of judgment. Unfortunately, however, for himself and for science, he acted otherwise. By admitting their authority, he revived in fresh force these obsolete and obnoxious enactments; and, by yielding to their power, he riveted for another century the almost broken chains of spiritual despotism.

It is a curious fact in the annals of heresy and sedition, that opinions maintained with impunity by one individual, have, in the same age, brought others to the stake or to the scaffold. The results of deep research or extravagant speculation seldom provoke hostility, when meekly announced as the deductions of reason or the convictions of conscience. As the dreams of a recluse or of an enthusiast, they may excite pity or call forth contempt; but, like seed quietly cast into the earth, they will rot and germinate according to the vitality with which they are endowed. But, if new and startling opinions are thrown in the face of the community—if they are uttered in triumph or in insult—in contempt of public opinion, or in derision of cherished errors, they lose the comeliness of truth in the rancour of their propagation; and they are like seed scattered in a hurricane, which only irritates and blinds the husbandman. Had Galileo concluded his System of the World with the quiet peroration of his apologist Campanella, and dedicated it to the Pope, it might have stood in the library of the Vatican, beside the cherished though equally heretical volume of Copernicus.

In the abjuration of his opinions by Galileo, Pope Urban VII. did not fail to observe the full extent of his triumph; and he exhibited the utmost sagacity in the means which he employed to secure it. While he endeavoured to overawe the enemies of the church by the formal promulgation of Galileo's sentence and abjuration, and by punishing the officials who had assisted in obtaining the license to print his work, he treated Galileo with the utmost lenity, and yielded to every request that was made to diminish, and almost suspend, the constraint under which he lay. The sentence of abjuration was ordered to be publicly read at several universities. At Florence the ceremonial was performed in the church of Santa Croce, and the friends and disciples of Galileo were especially summoned to witness the public degradation of their master. The inquisitor at Florence was ordered to be reprimanded for his conduct; and Riccardi, the master of the sacred palace, and Ciampoli, the secretary of Pope Urban himself, were dismissed from their situations.

Galileo had remained only four days in the prison of the Inquisition, when, on the application of Niccolini, the Tuscan ambassador, he was allowed to reside with him in his palace. As Florence still suffered under the contagious disease which we have already mentioned, it was proposed that Sienna should be the place of Galileo's confinement, and that his residence should be in one of the convents of that city. Niccolini, however, recommended the palace of the Archbishop Piccolomoni as a more suitable residence; and though the Archbishop was one of Galileo's best friends, the Pope agreed to the arrangement, and in the beginning of July Galileo quitted Rome for Sienna.

After having spent nearly six months under the hospitable roof of his friend, with no other restraint than that of being confined to the limits of the palace, Galileo was permitted to return to his villa near Florence under the same restrictions; and as the contagious disease had disappeared in Tuscany, he was able in the month of December to re-enter his own house at Arcetri, where he spent the remainder of his days.



CHAPTER VI.

Galileo loses his favourite Daughter—He falls into a state of melancholy and ill health—Is allowed to go to Florence for its recovery in 1638—But is prevented from leaving his House or receiving his Friends—His friend Castelli permitted to visit him in the presence of an Officer of the Inquisition—He composes his celebrated Dialogues on Local Motion—Discovers the Moon's Libration—Loses the sight of one Eye—The other Eye attacked by the same Disease—Is struck blind—Negociates with the Dutch Government respecting his Method of finding the Longitude—He is allowed free intercourse with his Friends—His Illness and Death in 1642—His Epitaph—His Social, Moral, and Scientific Character.

Although Galileo had now the happiness of rejoining his family under their paternal roof, yet, like all sublunary blessings, it was but of short duration. His favourite daughter Maria, who along with her sister had joined the convent of St Matthew in the neighbourhood of Arcetri, had looked forward to the arrival of her father with the most affectionate anticipations. She hoped that her filial devotion might form some compensation for the malignity of his enemies, and she eagerly assumed the labour of reciting weekly the seven penitentiary psalms which formed part of her father's sentence. These sacred duties, however, were destined to terminate almost at the moment they were begun. She was seized with a fatal illness in the same month in which she rejoined her parent, and before the month of April she was no more. This heavy blow, so suddenly struck, overwhelmed Galileo in the deepest agony. Owing to the decline of his health, and the recurrence of his old complaints, he was unable to oppose to this mental suffering the constitutional energy of his mind. The bulwarks of his heart broke down, and a flood of grief desolated his manly and powerful mind. He felt, as he expressed it, that he was incessantly called by his daughter—his pulse intermitted—his heart was agitated with unceasing palpitations—his appetite entirely left him, and he considered his dissolution so near at hand, that he would not permit his son Vicenzo to set out upon a journey which he had contemplated.

From this state of melancholy and indisposition, Galileo slowly, though partially, recovered, and, with the view of obtaining medical assistance, he requested leave to go to Florence. His enemies, however, refused this application, and he was given to understand that any additional importunities would be visited with a more vigilant surveillance. He remained, therefore, five years at Arcetri, from 1634 to 1638, without any remission of his confinement, and pursuing his studies under the influence of a continued and general indisposition.

There is no reason to think that Galileo or his friends renewed their application to the Church of Rome; but, in 1638, the Pope transmitted, through the Inquisitor Fariano, his permission that he might remove to Florence for the recovery of his health, on the condition that he should present himself at the office of the Inquisitor to learn the terms upon which this indulgence was granted. Galileo accepted of the kindness thus unexpectedly proffered. But the conditions upon which it was given were more severe than he expected. He was prohibited from leaving his house or admitting his friends; and so sternly was this system pursued, that he required a special order for attending mass during passion week.

The severity of this order was keenly felt by Galileo. While he remained at Arcetri, his seclusion from the world would have been an object of choice, if it had not been the decree of a tribunal; but to be debarred from the conversation of his friends in Florence—in that city where his genius had been idolised, and where his fame had become immortal, was an aggravation of punishment which he was unable to bear. With his accustomed kindness, the Grand Duke made a strong representation on the subject to his ambassador at the Court of Rome. He stated that, from his great age and infirmities, Galileo's career was near its close; that he possessed many valuable ideas, which the world might lose if they were not matured and conveyed to his friends; and that Galileo was anxious to make these communications to Father Castelli, who was then a stipendiary of the Court of Rome. The Grand Duke commanded his ambassador to see Castelli on the subject—to urge him to obtain leave from the Pope to spend a few months in Florence—and to supply him with money and every thing that was necessary for his journey. Influenced by this kind and liberal message, Castelli obtained an audience of the Pope, and requested leave to pay a visit to Florence. Urban instantly suspected the object of his journey; and, upon Castelli's acknowledging that he could not possibly refrain from seeing Galileo, he received permission to visit him in the company of an officer of the Inquisition. Castelli accordingly went to Florence, and, a few months afterwards, Galileo was ordered to return to Arcetri.

During Galileo's confinement at Sienna and Arcetri, between 1633 and 1638, his time was principally occupied in the composition of his "Dialogues on Local Motion," in which he treats of the strength and cohesion of solid bodies, of the laws of uniform and accelerated motions, of the motion of projectiles, and of the centre of gravity of solids. This remarkable work, which was considered by its author as the best of his productions, was printed by Louis Elzevir, at Amsterdam, and dedicated to the Count de Noailles, the French ambassador at Rome. Various attempts to have it printed in Germany had failed; and, in order to save himself from the malignity of his enemies, he was obliged to pretend that the edition published in Holland had been printed from a MS. entrusted to the French ambassador.

Although Galileo had for a long time abandoned his astronomical studies, yet his attention was directed, about the year 1636, to a curious appearance in the lunar disc, which is known by the name of the moon's libration. When we examine with a telescope the outline of the moon, we observe that certain parts of her disc, which are seen at one time, are invisible at another. This change or libration is of four different kinds, viz. the diurnal libration, the libration in longitude, the libration in latitude, and the spheroidal libration. Galileo discovered the first of these kinds of libration, and appears to have had some knowledge of the second; but the third was discovered by Hevelius, and the fourth by Lagrange.

This curious discovery was the result of the last telescopic observations of Galileo. Although his right eye had for some years lost its power, yet his general vision was sufficiently perfect to enable him to carry on his usual researches. In 1636, however, this affection of his eye became more serious; and, in 1637, his left eye was attacked with the same disease. His medical friends at first supposed that cataracts were formed in the crystalline lens, and anticipated a cure from the operation of couching. These hopes were fallacious. The disease turned out to be in the cornea, and every attempt to restore its transparency was fruitless. In a few months the white cloud covered the whole aperture of the pupil, and Galileo became totally blind. This sudden and unexpected calamity had almost overwhelmed Galileo and his friends. In writing to a correspondent he exclaims, "Alas! your dear friend and servant has become totally and irreparably blind. These heavens, this earth, this universe, which by wonderful observation I had enlarged a thousand times beyond the belief of past ages, are henceforth shrunk into the narrow space which I myself occupy. So it pleases God; it shall, therefore, please me also." His friend, Father Castelli, deplores the calamity in the same tone of pathetic sublimity:—"The noblest eye," says he, "which nature ever made, is darkened; an eye so privileged, and gifted with such rare powers, that it may truly be said to have seen more than the eyes of all that are gone, and to have opened the eyes of all that are to come."

Although Galileo had been thwarted in his attempt to introduce into the Spanish marine his new method of finding the longitude at sea, yet he never lost sight of an object to which he attached the highest importance. As the formation of correct tables of the motion of Jupiter's satellites was a necessary preliminary to its introduction, he had occupied himself for twenty-four years in observations for this purpose, and he had made considerable progress in this laborious task. After the publication of his "Dialogues on Motion," in 1636, he renewed his attempts to bring his method into actual use. For this purpose he addressed himself to Lorenzo Real, who had been the Dutch Governor-General in India, and offered the free use of his method to the States-General of Holland.[36] The Dutch government received this proposal with an anxious desire to have it carried into effect. At the instigation of Constantine Huygens, the father of the illustrious Huygens, and the secretary to the Prince of Orange, they appointed commissioners to communicate with Galileo; and while they transmitted him a gold chain as a mark of their esteem, they at the same time assured him, that if his plan should prove successful it should not pass unrewarded. The commissioners entered into an active correspondence with Galileo, and had even appointed one of their number to communicate personally with him in Italy. Lest this, however, should excite the jealousy of the court of Rome, Galileo objected to the arrangement, so that the negociation was carried on solely by correspondence.

[36] It is a curious fact that Morin had about this time proposed to determine the longitude by the moon's distance from a fixed star, and that the commissioners assembled in Paris to examine it requested Galileo's opinion of its value and practicability. Galileo's opinion was highly unfavourable. He saw clearly, and explained distinctly, the objection to Morin's method, arising from the imperfection of the lunar tables, and the inadequacy of astronomical instruments; but he seemed not to be conscious that the very same objections applied with even greater force to his own method, which has since been supplanted by that of the French savant. See Life of Galileo, Library of Useful Knowledge, p. 94.

It was at this time that Galileo was struck with blindness. His friend and pupil, Renieri, undertook in this emergency to arrange and complete his observations and calculations; but before he had made much progress in the arduous task, each of the four commissioners died in succession, and it was with great difficulty that Constantine Huygens succeeded in renewing the scheme. It was again obstructed, however, by the death of Galileo; and when Renieri was about to publish, by the order of the Grand Duke, the "Ephemeris," and "Tables of the Jovian Planets," he was attacked with a mortal disease, and the manuscripts of Galileo, which he was on the eve of publishing, were never more heard of. By such a series of misfortunes were the plans of Galileo and of the States-General completely overthrown. It is some consolation, however, to know that neither science nor navigation suffered any severe loss. Notwithstanding the perfection of our present tables of Jupiter's satellites, and of the astronomical instruments by which their eclipses may be observed, the method of Galileo is still impracticable at sea.

In consequence of the strict seclusion to which Galileo had been subjected, he was in the practice of dating his letters from his prison at Arcetri; but after he had lost the use of his eyes, the Inquisition seems to have relaxed its severity, and to have allowed him the freest intercourse with his friends. The Grand Duke of Tuscany paid him frequent visits; and among the celebrated strangers who came from distant lands to see the ornament of Italy, were Gassendi, Deodati, and our illustrious countryman Milton. During the last three years of his life, his eminent pupil Viviani formed one of his family; and in October 1641, the celebrated Torricelli, another of his pupils, was admitted to the same distinction.

Though the powerful mind of Galileo still retained its vigour, yet his debilitated frame was exhausted with mental labour. He often complained that his head was too busy for his body; and the continuity of his studies was frequently broken with attacks of hypochondria, want of sleep, and acute rheumatic pains. Along with these calamities, he was afflicted with another still more severe—with deafness almost total; but though he was now excluded from all communication with the external world, yet his mind still grappled with the material universe, and while he was studying the force of percussion, and preparing for a continuation of his "Dialogues on Motion," he was attacked with fever and palpitation of the heart, which, after continuing two months, terminated fatally on the 8th of January 1642, in the 78th year of his age.

Having died in the character of a prisoner of the Inquisition, this odious tribunal disputed his right of making a will, and of being buried in consecrated ground. These objections, however, were withdrawn; but though a large sum was subscribed for erecting a monument to him in the church of Santa Croce, in Florence, the Pope would not permit the design to be carried into execution. His sacred remains were, therefore, deposited in an obscure corner of the church, and remained for more than thirty years unmarked with any monumental tablet. The following epitaph, given without any remark in the Leyden edition of his Dialogues, is, we presume, the one which was inscribed on a tablet in the church of Santa Croce:—

GALILAEO GALILAEI Florentino, Philosopho et Geometrae vere lynceo, Naturae Oedipo, Mirabilium semper inventorum machinatori, Qui inconcessa adhuc mortalibus gloria Caelorum provincias auxit Et universo dedit incrementum: Non enim vitreos spherarum orbes Fragilesque stellas conflavit: Sed aeterna mundi corpore Mediceae beneficentiae dedicavit, Cujus inextincta gloriae cupiditas Ut oculos nationum Saeculorumque omnium Videre doceret, Proprios impendit oculos. Cum jam nil amplius haberet natura Quod ipse videret. Cujus inventa vix intra rerum limites comprehensa Firmamentum ipsum non solum continet, Sed etiam recipit. Qui relictis tot scientiarum monumentis Plura secum tulit, quam reliquit. Gravi enim Sed nondum affecta senectute, Novis contemplationibus Majorem gloriam affectans Inexplebilem sapientiae animam Immaturo nobis obitu Exhalavit Anno Domini MCXLII. AEtatis suae LXXVIII.



At his death, in 1703, Viviani purchased his property, with the charge of erecting a monument over Galileo's remains and his own. This design was not carried into effect till 1737, at the expense of the family of Nelli, when both their bodies were disinterred, and removed to the site of the splendid monument which now covers them. This monument contains the bust of Galileo, with figures of Geometry and Astronomy. It was designed by Giulio Foggini. Galileo's bust was executed by Giovanni Battista Foggini; the figure of Astronomy by Vincenzio Foggini, his son; and that of Geometry by Girolamo Ticciati.

Galileo's house at Arcetri still remains. In 1821 it belonged to one Signor Alimari, having been preserved in the state in which it was left by Galileo; it stands very near the convent of St Matthew, and about a mile to the S. E. of Florence. An inscription by Nelli, over the door of the house, still remains.

The character of Galileo, whether we view him as a member of the social circle, or as a man of science, presents many interesting and instructive points of contemplation. Unfortunate, and to a certain extent immoral, in his domestic relations, he did not derive from that hallowed source all the enjoyments which it generally yields; and it was owing to this cause, perhaps, that he was more fond of society than might have been expected from his studious habits. His habitual cheerfulness and gaiety, and his affability and frankness of manner, rendered him an universal favourite among his friends. Without any of the pedantry of exclusive talent, and without any of that ostentation which often marks the man of limited though profound acquirements, Galileo never conversed upon scientific or philosophical subjects except among those who were capable of understanding them. The extent of his general information, indeed, his great literary knowledge, but, above all, his retentive memory, stored with the legends and the poetry of ancient times, saved him from the necessity of drawing upon his own peculiar studies for the topics of his conversation.

Galileo was not less distinguished for his hospitality and benevolence; he was liberal to the poor, and generous in the aid which he administered to men of genius and talent, who often found a comfortable asylum under his roof. In his domestic economy he was frugal without being parsimonious. His hospitable board was ever ready for the reception of his friends; and, though he was himself abstemious in his diet, he seems to have been a lover of good wines, of which he received always the choicest varieties out of the Grand Duke's cellar. This peculiar taste, together with his attachment to a country life, rendered him fond of agricultural pursuits, and induced him to devote his leisure hours to the cultivation of his vineyards.

In his personal appearance Galileo was about the middle size, and of a square-built, but well-proportioned, frame. His complexion was fair, his eyes penetrating, and his hair of a reddish hue. His expression was cheerful and animated, and though his temper was easily ruffled, yet the excitement was transient, and the cause of it speedily forgotten.

One of the most prominent traits in the character of Galileo was his invincible love of truth, and his abhorrence of that spiritual despotism which had so long brooded over Europe. His views, however, were too liberal, and too far in advance of the age which he adorned; and however much we may admire the noble spirit which he evinced, and the personal sacrifices which he made, in his struggle for truth, we must yet lament the hotness of his zeal and the temerity of his onset. In his contest with the Church of Rome, he fell under her victorious banner; and though his cause was that of truth, and hers that of superstition, yet the sympathy of Europe was not roused by his misfortunes. Under the sagacious and peaceful sway of Copernicus, astronomy had effected a glorious triumph over the dogmas of the Church; but under the bold and uncompromising sceptre of Galileo all her conquests were irrecoverably lost.

The scientific character of Galileo, and his method of investigating truth, demand our warmest admiration. The number and ingenuity of his inventions, the brilliant discoveries which he made in the heavens, and the depth and beauty of his researches respecting the laws of motion, have gained him the admiration of every succeeding age, and have placed him next to Newton in the lists of original and inventive genius. To this high rank he was doubtless elevated by the inductive processes which he followed in all his inquiries. Under the sure guidance of observation and experiment, he advanced to general laws; and if Bacon had never lived, the student of nature Would have found, in the writings and labours of Galileo, not only the boasted principles of the inductive philosophy, but also their practical application to the highest efforts of invention and discovery.



LIFE OF TYCHO BRAHE.



CHAPTER I.

Tycho's Birth, Family, and Education—An Eclipse of the Sun turns his attention to Astronomy—Studies Law at Leipsic—But pursues Astronomy by stealth—His Uncle's Death—He returns to Copenhagen, and resumes his Observations—Revisits Germany—Fights a Duel, and loses his Nose—Visits Augsburg, and meets Hainzel—Who assists him in making a large Quadrant—Revisits Denmark—And is warmly received by the King—He settles at his Uncle's Castle of Herritzvold—His Observatory and Laboratory—Discovers the new Star in Cassiopeia—Account of this remarkable Body—Tycho's Marriage with a Peasant Girl—Which irritates his Friends—His Lectures on Astronomy—He visits the Prince of Hesse—Attends the Coronation of the Emperor Rudolph at Ratisbon—He returns to Denmark.

Among the distinguished men who were destined to revive the sciences, and to establish the true system of the universe, Tycho Brahe holds a conspicuous place. He was born on the 14th December 1546, at Knudstorp, the estate of his ancestors, which is situated near Helsingborg, in Scania, and was the eldest son and the second child of a family of five sons and five daughters. His father, Otto Brahe, who was descended from a noble Swedish family, was in such straitened circumstances, that he resolved to educate his sons for the military profession; but Tycho seems to have disliked the choice that was made for him; and his next brother, Steno, who appears to have had a similar feeling, exchanged the sword for the more peaceful occupation of Privy Councillor to the King. The rest of his brothers, though of senatorial rank, do not seem to have extended the renown of their family; but their youngest sister, Sophia, is represented as an accomplished mathematician, and is said to have devoted her mind to astronomy as well as to the astrological reveries of the age.

George Brahe, the brother of Otto, having no children of his own, resolved to adopt and to educate one of his nephews. On the birth of Tycho, accordingly, he was desirous of having him placed under his wife's care; but his parents could not be prevailed upon to part with their child till after the birth of Steno, their second son.

Having been instructed in reading and writing under proper masters, Tycho began the study of Latin in his seventh year; and, in opposition to his father's views, he prosecuted it for five years under private teachers, from whom he received also occasional instruction in poetry and the belles lettres.

In April 1559, about three years after his father's death, Tycho was sent to the University of Copenhagen, to study rhetoric and philosophy, with the view of preparing for the study of the law, and qualifying himself for some of those political offices which his rank entitled him to expect. In this situation he contracted no fondness for any particular study; but after he had been sixteen months at college, an event occurred which directed all the powers of his mind to the science of astronomy. The attention of the public had been long fixed on a great eclipse of the sun, which was to happen on the 21st August 1560; and as in those days a phenomenon of this kind was linked with the destinies of nations as well as of individuals, the interest which it excited was as intense as it was general. Tycho watched its arrival with peculiar anxiety. He read the astrological diaries of the day, in which its phases and its consequences were described; and when he saw the sun darkened at the very moment that had been predicted, and to the very extent that had been delineated, he resolved to make himself master of a science which was capable of predicting future events, and especially that branch of it which connected these events with the fortunes and destinies of man. With this view he purchased the Tabulae Bergenses, calculated by John Stadius, and began with ardour the study of the planetary motions.

When Tycho had completed his course at Copenhagen, he was sent, in February 1562, under the charge of a tutor to study jurisprudence at Leipsic. Astronomy, however, engrossed all his thoughts; and he had no sooner escaped from the daily surveillance of his master, than he rushed with headlong impetuosity into his favourite pursuits. With his pocket money he purchased astronomical books, which he read in secret; and by means of a celestial globe, the size of his fist, he made himself acquainted with the stars, and followed them night after night through the heavens, when sleep had lulled the vigilance of his preceptor. By means of the Ephemerides of Stadius, he learned to distinguish the planets, and to trace them through their direct and retrograde movements; and having obtained the Alphonsine and Prutenic Tables, and compared his own calculations and observations with those of Stadius, he observed great differences in the results, and from that moment he seems to have conceived the design of devoting his life to the accurate construction of tables, which he justly regarded as the basis of astronomy.

With this view, he applied himself secretly to the study of arithmetic and geometry; and, without the assistance of a master, he acquired that mathematical knowledge which enabled him to realise these early aspirations. His ardour for astronomy was still farther inflamed, and the resolution which it inspired still farther strengthened, by the great conjunction of Jupiter and Saturn, which took place in August 1563. The calculated time of this phenomenon differed considerably from the true time which was observed; and in determining the instant of conjunction Tycho felt in the strongest manner the imperfection of the instruments which he used. For this purpose he employed a sort of compass, one leg of which was directed to one planet and the second to the other planet or fixed star; and, by measuring the angular opening between them, he determined the distance of the two celestial bodies. By this rude contrivance he found that the Alphonsine Tables erred a whole month in the time of conjunction, while the Copernican ones were at least several days in error. To this celebrated conjunction Tycho ascribed the great plague which in subsequent years desolated Europe, because it took place in the beginning of Leo, and not far from the nebulous stars of Cancer, two of the zodiacal signs which are reckoned by Ptolemy "suffocating and pestilent!"

There dwelt at this time at Leipsic an ingenious artisan named Scultetus, who was employed by Homelius, the professor of mathematics in that city, to assist him in the construction of his instruments. Having become acquainted with this young man, Tycho put into his hand a wooden radius, such as was recommended by Gemma Frisius, for the purpose of having it divided in the manner adopted by Homelius; and with this improved instrument he made a great number of astronomical observations out of his window, without ever exciting the suspicions of his tutor.

Having spent three years at Leipsic, he was about to make the tour of Germany, when, in consequence of his uncle's death, he was summoned to his native country to inherit the fortune which had been left him. He accordingly quitted Leipsic about the middle of May 1565, and after having arranged his domestic concerns in Denmark, he continued his astronomical observations with the radius constructed for him by Scultetus. The ardour with which he pursued his studies gave great umbrage to his friends as well as to his relations. He was reproached for having abandoned the profession of the law; his astronomical observations were ridiculed as not only useless but degrading, and, among his numerous connexions, his maternal uncle, Steno Bille, was the only one who applauded him for following the bent of his genius. Under these uncomfortable circumstances he resolved to quit his country, and pay a visit to the most interesting cities of Germany.

At Wittemberg, where he arrived in April 1566, he resumed his astronomical observations; but, in consequence of the plague having broken out in that city, he removed to Rostoch in the following autumn. Here an accident occurred which had nearly deprived him of his life. On the 10th December he was invited to a wedding feast; and, among other guests, there was present a noble countryman of his own, Manderupius Pasbergius. Some difference having arisen between them on this occasion, they parted with feelings of mutual displeasure. On the 27th of the same month they met again at some festive games, and having revived their former quarrel, they agreed to settle their differences by the sword. They accordingly met at 7 o'clock in the evening of the 29th, and fought in total darkness. In this blind combat, Manderupius cut off the whole of the front of Tycho's nose, and it was fortunate for astronomy that his more valuable organs were defended by so faithful an outpost. The quarrel, which is said to have originated in a difference of opinion respecting their mathematical acquirements, terminated here; and Tycho repaired his loss by cementing upon his face a nose of gold and silver, which is said to have formed a good imitation of the original.

During the years 1567 and 1568, Tycho continued to reside at Rostoch, with the exception of a few months, during which he made a rapid journey into Denmark. He lived in a house in the college of the Jesuits, which he had rented on account of its fitness for celestial observations; but, though he intended to spend the winter under its roof, he had made no arrangement respecting his future life, leaving it, as he said, in the hands of Providence. A desire, however, to visit the south of Germany induced him to quit Rostoch, and having crossed the Danube, he paid a visit to Augsburg.

Upon entering this ancient city, Tycho was particularly struck with the grandeur of its fortifications, the splendour of its private houses, and the beauty of its fountains; and, after a short residence within its walls, he was still more delighted with the industry of the people, the refinement of the higher classes, and the love of literature and science which was cherished by its wealthy citizens. Among the interesting acquaintances which he formed at Augsburg, were two brothers, John and Paul Hainzel, the one a septemvir, and the other the consul or burgomaster. They were both distinguished by their learning, and both of them, particularly Paul, were ardent lovers of astronomy. Tycho had hitherto no other astronomical instrument than the coarse radius which was made for him by Scultetus, and he waited only for a proper occasion to have a larger and better instrument constructed for his use. Having now the command of workmen who could execute his plans, he conceived the bold design of making a divided instrument which should distinctly exhibit single minutes of a degree. While he was transferring the first rude conception of his instrument to paper, Paul Hainzel entered his study, and was so struck with the grandeur of the plan, that he instantly undertook to have it executed at his own expense. The projected instrument was a quadrant of fourteen cubits radius! and Tycho and his friend entered upon its construction with that intense ardour which is ever crowned with success.

In the village of Gegginga, about half a mile to the south of the city, Paul Hainzel had a country house, the garden of which was chosen as the spot where the quadrant was to be fixed. The best artists in Augsburg, clockmakers, jewellers, smiths, and carpenters, were engaged to execute the work, and from the zeal which so novel an instrument inspired, the quadrant was completed in less than a month. Its size was so great that twenty men could with difficulty transport it to its place of fixture. The two principal rectangular radii were beams of oak; the arch which lay between their extremities was made of solid wood of a particular kind, and the whole was bound together by twelve beams. It received additional strength from several iron bands, and the arch was covered with plates of brass, for the purpose of receiving the 5400 divisions into which it was to be subdivided. A large and strong pillar of oak, shod with iron, was driven into the ground, and kept in its place by solid mason work. To this pillar the quadrant was fixed in a vertical plane, and steps were prepared to elevate the observer, when stars of a low altitude required his attention. As the instrument could not be conveniently covered with a roof, it was protected from the weather by a covering made of skins, but notwithstanding this and other precautions, it was broken to pieces by a violent storm, after having remained uninjured for the space of five years.

As this quadrant was fitted only to determine the altitudes of the celestial bodies, Tycho constructed a large sextant for the purpose of measuring their distances. It consisted of two radii, which opened and shut round a centre, and which were nearly four cubits long, and also of two arches, one of which was graduated, while the other served to keep the radii in the same plane. After the radii had been opened or shut till they nearly comprehended the angle between the stars to be observed, the adjustment was completed by means of a very fine tangent screw. With this instrument Tycho made many excellent observations during his stay at Augsburg. He began also the construction of a wooden globe about six feet in diameter. Its outer surface was turned with great accuracy into a sphere, and kept from warping by interior bars of wood supported at its centre.

After receiving a visit from the celebrated Peter Ramus, who subsequently fell a victim at the massacre of St Bartholomew, Tycho left Augsburg, having received a promise from his friend Hainzel that he would communicate to him the observations made with his large quadrant, and with the sextant which he had given him in a present. He paid a visit to Philip Appian in passing through Ingolstadt, and returned to his native country about the end of 1571.

The fame which he had acquired as an astronomer procured for him a warmer reception than that which he had formerly experienced. The King invited him to court, and his friends and admirers loaded him with kindness. His uncle, Steno Bille, who now lived at the ancient convent of Herritzvold, and who had always taken a deep interest in the scientific character of his nephew, not only invited him to his house, but assigned to him for an observatory the part of it which was best adapted for that purpose. Tycho cheerfully accepted of this liberal offer. The immediate proximity of Herritzvold to Knudstorp, rendered this arrangement peculiarly convenient, and in the house of his uncle he experienced all that kindness and consideration which natural affection and a love of science combined to cherish. When Steno learned that the study of chemistry was one of the pursuits of his nephew, he granted him a spacious house, a few yards distant from the convent, for his laboratory. Tycho lost no time in fitting up his observatory, and in providing his furnaces; and regarding gold and silver and the other metals as the stars of the earth, he used to represent his two opposite pursuits as forming only one science, namely, celestial and terrestrial astronomy.

In the hopes of enriching himself by the pursuits of alchemy, Tycho devoted most of his attention to those satellites of gold and silver which now constituted his own system, and which disturbed by their powerful action the hitherto uniform movements of their primary. His affections were ever turning to Germany, where astronomers of kindred views, and artists of surpassing talent were to be found in almost every city. The want of money alone prevented him from realizing his wishes; and it was in the hope of attaining the means of travelling, that he in a great measure forsook his sextants for his crucibles. In order, however, that he might have one good instrument in his observatory, he constructed a sextant similar to, but somewhat larger than, that which he had presented to Hainzel. Its limb was made of solid brass, and was exquisitely divided into single minutes of a degree. Its radii were strengthened with plates of brass, and the apparatus for opening and shutting them was made with great accuracy.

The possession of this instrument was peculiarly fortunate for Tycho, for an event now occurred which roused him from his golden visions, and directed all his faculties into their earlier and purer current. On the 11th November 1572, when he was returning to supper from his laboratory, the clearness of the sky inspired him with the desire of completing some particular observations. On looking up to the starry firmament he was surprised to see an extraordinary light in the constellation of Cassiopeia, which was then above his head. He felt confident that he had never before observed such a star in that constellation, and distrusting the evidence of his own senses, he called out the servants and the peasants, and having received their testimony that it was a huge star such as they had never seen before, he was satisfied of the correctness of his own vision. Regarding it as a new and unusual phenomenon, he hastened to his observatory, adjusted his sextant, and measured its distances from the nearest stars in Cassiopeia. He noted also its form, its magnitude, its light, and its colour, and he waited with great anxiety for the next night that he might determine the important point whether it was a fixed star, or a body within, or near to, our own system.

For several years Tycho had been in the practice of calculating, at the beginning of each year, a sort of almanac for his own use, and in this he inserted all the observations which he had made on the new star, and the conclusions which he had drawn from them. Having gone to Copenhagen in the course of the ensuing spring, he shewed this manuscript to John Pratensis, a Professor, in whose house he was always hospitably received. Charles Danzeus, the French ambassador, and a person of great learning, having heard of Tycho's arrival, invited himself to dine with him at the house of Pratensis. The conversation soon turned upon the new star, and Tycho found his companion very sceptical about its existence. Danzeus was particularly jocular on the subject, and attacked the Danes for their inattention to so important a science as astronomy. Tycho received this lecture in good temper, and with the anxious expectation that a clear sky would enable him to give a practical refutation of the attack which was made upon his country. The night turned out serene, and the whole party saw with astonishment the new star under the most favourable circumstances. Pratensis conceived that it was similar to the one observed by Hipparchus, and urged Tycho to publish the observations which he had made upon it. Tycho refused to accede to this request, on the pretext that his work was not sufficiently perfect; but the true reason, as he afterwards acknowledged, was, that he considered it would be a disgrace for a nobleman, either to study such subjects, or to communicate them to the public. This absurd notion was with some difficulty overcome, and through the earnest entreaties and assistance of Pratensis, his work on the new star was published in 1573.

This remarkable body presents to us one of the most interesting phenomena in astronomy. The date of its first appearance has not been exactly ascertained. Tycho saw it on the 11th November, but Cornelius Gemma had seen it on the 9th, Paul Hainzel saw it on the 7th of August at Augsburg, and Wolfgangus Schulerus observed it at Wittenberg on the 6th. Tycho conjectures that it was first seen on the 5th, and Hieronymus Munosius asserts that at Valentia, in Spain, it was not seen on the 2d, when he was shewing that part of the heavens to his pupils. This singular body continued to be seen during 16 months, and did not disappear till March 1574. In its appearance it was exactly like a star, having none of the distinctive marks of a comet. It twinkled strongly, and grew larger than Lyra or Sirius, or any other fixed star. It seemed to be somewhat larger than Jupiter, when he is nearest the earth, and rivalled Venus in her greatest brightness. In the first month of its appearance it was less than Jupiter; in the second it equalled him; in the third it surpassed him in splendour; in the fourth it was equal to Sirius; in the fifth to Lyra; in the sixth and seventh to stars of the second magnitude; in the eighth, ninth, and tenth, to stars of the third magnitude; in the eleventh, twelfth, and thirteenth, to stars of the fourth magnitude; in the fourteenth and fifteenth to stars of the fifth magnitude; and in the sixteenth month to stars of the sixth magnitude. After this it became so small that it at last disappeared. Its colour changed also with its size. At first it was white and bright; in the third month it began to become yellowish; in the fifth it became reddish like Aldebaran; and in the seventh and eighth it became bluish like Saturn; growing afterwards duller and duller. Its place in the heavens was invariable. Its longitude was in the 6th degree and 54th minute of Taurus; and its latitude 53 deg. 45' north. Its right ascension was 0 deg. 26-2/5' and its declination 61 deg. 46-3/4'. It had no parallax, and was unquestionably situated in the region of the fixed stars.

After Tycho had published his book, he proposed to travel into Germany and Italy, but he was seized with a fever, and he had no sooner recovered from it, than he became involved in a love affair, which frustrated all his schemes. Although Tycho was afraid of casting a stain upon his nobility by publishing his observations on the new star, yet he did not scruple to debase his lineage by marrying a peasant girl of the village of Knudstorp. This event took place in 1573, and in 1574 his wife gave birth to his daughter Magdalene. Tycho's noble relations were deeply offended at this imprudent step; and so far did the mutual animosity of the parties extend, that the King himself was obliged to effect a reconciliation.

The fame of our author as an astronomer and mathematician was now so high, that several young Danish nobles requested him to deliver a course of lectures upon these interesting subjects. This application was seconded by Pratensis, Danzeus, and all his best friends; but their solicitations were vain. The King at last made the request in a way which ensured its being granted, and Tycho delivered a course of lectures, in which he not only gave a full view of the science of astronomy, but defended and explained all the reveries of astrology.

Having finished his lectures, and arranged his domestic affairs, he set out on his projected journey about the beginning of the spring of 1575, leaving behind him his wife and daughter, till he should fix upon a place of permanent residence. The first town which he visited was Hesse-Cassel, the residence of William, Landgrave of Hesse, whose patronage of astronomy, and whose skill in making celestial observations, have immortalized his name. Here Tycho spent eight or ten delightful days, during which the two astronomers were occupied one half of the day in scientific conversation, and the other half in astronomical observations; and he would have prolonged a visit which gave him so much pleasure, had not the death of one of the Landgrave's daughters interrupted their labours. Passing through Frankfort, Tycho went into Switzerland; and, after visiting many cities on his way, he fixed upon Basle as a place of residence, not only from its centrical position, but from the salubrity of the air, and the cheapness of living. From Switzerland he went to Venice, and, in returning through Germany, he came to Ratisbon, at the time of the congress, which had been called together on the 1st of November, for the coronation of the Emperor Rudolph. On this occasion he met with several distinguished individuals, who were not only skilled in astronomy, but who were among its warmest patrons. From Ratisbon he passed to Saalfeld, and thence to Wittemburg, where he saw the parallactic instruments and the wooden quadrant which had been used by John Pratensis in determining the latitude of the city, and in measuring the altitudes of the new star.

Tycho was now impatient for home, and he lost no time in returning to Denmark, where events were awaiting him which frustrated all his schemes, by placing him in the most favourable situation for promoting his own happiness, and advancing the interests of astronomy.



CHAPTER II.

Frederick II. patronises Tycho—And resolves to establish him in Denmark—Grants him the Island of Huen for Life—And Builds the splendid Observatory of Uraniburg—Description of the Island, and of the Observatory—Account of its Astronomical Instruments—Tycho begins his Observations—His Pupils—Tycho is made Canon of Rothschild, and receives a large Pension—His Hospitality to his Visitors—Ingratitude of Witichius—Tycho sends an Assistant to take the Latitude of Frauenburg and Konigsberg—Is visited by Ulric, Duke of Mecklenburg—Change in Tycho's fortunes.

The patronage which had been extended to astronomers by several of the reigning princes of Germany, especially by the Landgrave of Hesse, and Augustus, Elector of Saxony, had begun to excite a love of science in the minds of other sovereigns. The King of Denmark seems to have felt it as a stain upon his character, that the only astronomer in his dominions should carry on his observations in distant kingdoms and adorn by his discoveries other courts than his own. With this feeling he sent ambassadors to Hesse-Cassel to inquire after Tycho, and to intimate to him his wish that he should return to Denmark, and his anxiety to promote the advancement of astronomy in his own dominions. Tycho had left Cassel when these messengers arrived, and had heard nothing of the King's intentions till he was about to quit Knudstorp with his family for Basle. At this time he was surprised at the arrival of a noble messenger, who brought a letter requesting him to meet the King as soon as possible at Copenhagen. Tycho lost no time in obeying the royal summons. The King received him with the most flattering kindness. He offered to give him a grant for life of the island of Huen, between Denmark and Sweden, and to construct and furnish with instruments, at his own expense, an observatory, as well as a house for the accommodation of his family, together with a laboratory for carrying on his chemical inquiries. Tycho, who truly loved his country, was deeply affected with the munificence of the royal offer. He accepted of it with that warmth of gratitude which it was calculated to inspire; and he particularly rejoiced in the thought that if any success should attend his future labours, the glory of it would belong to his native land.

The island of Huen is about sxix miles from the coast of Zealand, three from that of Sweden, and fourteen from Copenhagen. It is six miles in circumference, and rises into the form of a mountain, which, though very high, terminates in a plain. It is nowhere rocky, and even in the time of Tycho it produced the best kinds of grain, afforded excellent pasturage for horses, cattle, and sheep, and possessed deer, hares, rabbits, and partridges in abundance. It contained at that time only one village, with about forty inhabitants.

Having surveyed his new territory, Tycho resolved to build a magnificent tower in the centre of the elevated plain, which he resolved to call Uraniburg, or The City of the Heavens. Having made the necessary arrangements, he repaired to the island on the 8th of August, and his friend Charles Danzeus laid the foundation stone of the new observatory, which consisted of a slab of porphyry, with the following inscription:—

REGNANTE IN DANIA FREDERICO II., CAROLUS DANZAEUS AQUITANUS R. G. I. D. L.,[37] DOMUI HUIC PHILOSOPHIAE, IMPRIMISQUE ASTRORUM CONTEMPLATIONI, REGIS DECRETO A NOBILI VIRO TYCHONE BRAHE DE KNUDSTRUP EXTRUCTAE VOTIVUM HUNC LAPIDEM MEMORIAE ET FELICIS AUSPICII ERGO P. ANNO CIC.IC.LXXVI.[38] VI ID. AUGUSTI.

[37] Regis Gallorum in Dania Legatus.

[38] Transcriber's footnote: The second Cs in CIC and IC are printed reversed in the original.

This ceremony was performed early in the morning of a splendid day, in which the rising sun threw its blessing upon Frederick, and upon the party of noblemen and philosophers who had assembled to testify their love of science. An entertainment was provided for the occasion, and copious libations of a variety of wines were offered for the success of the undertaking.

The observatory was surrounded by a rampart, each face of which was three hundred feet long. About the middle of each face the rampart became a semicircle, the inner diameter of which was ninety feet. The height of the rampart was twenty-two feet, and its thickness at the base twenty. Its four angles corresponded exactly with the four cardinal points, and at the north and south angles were erected turrets, of which one was a printing-house, and the other the residence of the servants. Gates were erected at the east and west angles, and above them were apartments for the reception of strangers. Within the rampart was a shrubbery with about three hundred varieties of trees; and at the centre of each semicircular part of the rampart was a bower or summer-house. This shrubbery surrounded the flower-garden, which was terminated within by a circular wall about forty-five feet high, which enclosed a more elevated area, in the centre of which stood the principal building in the observatory, and from which four paths led to the above-mentioned angles, with as many doors for entering the garden.

The principal building was about sixty feet square. The doors were placed on the east and west sides; and to the north and south fronts were attached two round towers, whose inner diameter was about thirty-two feet, and which formed the observatories which had windows in their roof, that could be opened towards any part of the heavens. The accommodations for the family were numerous and splendid. Under the observatory, in the south tower, was the museum and library, and below this again was the laboratory in a subterraneous crypt, containing sixteen furnaces of various kinds. Beneath this was a well forty feet deep, from which water was distributed by syphons to every part of the building.

Besides the principal building there were other two situated without the rampart, one to the north, containing a workshop for the construction of astronomical and other instruments, and the other to the south, which was occupied as a sort of farm-house. These buildings cost the King of Denmark 100,000 rix-dollars (L20,000), and Tycho is said to have expended upon them a similar sum.

As the two towers could not accommodate the instruments which Tycho required for his observations, he found it necessary to erect, on the hill about sixty paces to the south of Uraniburg, a subterranean observatory, in which he might place his larger instruments, which required to be firmly fixed, and to be protected from the wind and the weather. This observatory, which he called Stiern-berg, or the mountain, of the stars, consisted of several crypts, separated by solid walls, and to these there was a subterranean passage from the laboratory in Uraniburg. The various buildings which Tycho erected were built in a regular style of architecture, and were highly ornamented, not only with external decorations, but with the statues and pictures of the most distinguished astronomers, from Hipparchus and Ptolemy down to Copernicus, and with inscriptions and poems in honour of astronomers.

While these buildings were erecting, and after their completion, Tycho was busily occupied in preparing instruments for observation. These were of the most splendid description, and the reader will form some notion of their grandeur and their expense from the following list:—

In the south and greater Observatory.

1. A semicircle of solid iron, covered with brass, four cubits radius.

2. A sextant of the same materials and size.

3. A quadrant of one and a half cubits radius, and an azimuth circle of three cubits.

4. Ptolemy's parallactic rules, covered with brass, four cubits in the side.

5. The sextant already described in page 134.

6. Another quadrant, like No. 3.

7. Zodiacal armillaries of melted brass, and turned out of the solid, of three cubits in diameter.

Near this observatory was a large clock, with one wheel two cubits in diameter, and two smaller ones, which, like it, indicated hours, minutes, and seconds.

In the south and lesser Observatory.

8. An armillary sphere of brass, with a steel meridian, whose diameter was about 4 cubits.

In the north Observatory.

9. Brass parallactic rules, which revolved in azimuth above a brass horizon, twelve feet in diameter.

10. A half sextant, of four cubits radius.

11. A steel sextant.

12. Another half sextant, with steel limb, four cubits radius.

13. The parallactic rules of Copernicus.

14. Equatorial armillaries.

15. A quadrant of a solid plate of brass, five cubits in radius, shewing every ten seconds.

16. In the museum was the large globe made at Augsburg, see p. 134.

In the Stiern-berg Observatory.

17. In the central part, a large semicircle, with a brass limb, and three clocks, shewing hours, minutes, and seconds.

18. Equatorial armillaries of seven cubits, with semi-armillaries of nine cubits.

19. A sextant of four cubits radius.

20. A geometrical square of iron, with an intercepted quadrant of five cubits, and divided into fifteen seconds.

21. A quadrant of four cubits radius, shewing ten seconds, with an azimuth circle.

22. Zodiacal armillaries of brass, with steel meridians, three cubits in diameter.

23. A sextant of brass, kept together by screws, and capable of being taken to pieces for travelling with. Its radius was four cubits.

24. A moveable armillary sphere, three cubits in diameter.

25. A quadrant of solid brass, one cubit radius, and divided into minutes by Nonian circles.

26. An astronomical radius of solid brass, three cubits long.

27. An astronomical ring of brass, a cubit in diameter.

28. A small brass astrolabe.

In almost all the instruments now enumerated, the limb was subdivided by diagonal lines, a method which Tycho first brought into use, but which, in modern times, has been superseded by the inventions of Nonius and Vernier.

When Tycho had thus furnished his observatory, he devoted himself to the examination of the stars; and during the twenty-one years which he spent in this delightful occupation, he made vast additions to astronomical science. In order to instruct the young in the art of observation, and educate assistants for his observatory, he had sometimes under his roof from six to twelve pupils, whom he boarded and educated. Some of these were named by the King, and educated at his expense. Others were sent by different academies and cities; and several, who had presented themselves of their own accord, were liberally admitted by the generous astronomer.

As Tycho had spent nearly a ton of gold (about 100,000 dollars) in his outlay at Uraniburg, his own income was reduced to very narrow limits. To supply this defect, Frederick gave him an annual pension of 2000 dollars, beside an estate in Norway, and made him Canon of the Episcopal Church of Rothschild, or Prebend of St Laurence,[39] which had an annual income of 1000 dollars, and which was burdened only with the expense of keeping up the chapel containing the Mausolea of the Kings of the family of Oldenburg.

[39] This office had been usually conferred on the King's Chancellor.

It would be an unprofitable task, and one by no means interesting to the general reader, to give a detailed history of the various astronomical observations and discoveries which were made by Tycho during the twenty years that he spent at Uraniburg. Every phenomenon that appeared in the heavens, he observed with the greatest care; while he at the same time carried on regular series of observations for determining the places of the fixed stars, and for improving the tables of the sun, moon, and planets. Though almost wholly devoted to these noble pursuits, yet he kept an open house, and received, with unbounded hospitality, the crowds of philosophers, nobles, and princes who came to be introduced to the first astronomer of the age, and to admire the splendid temple which the Danish Sovereign had consecrated to science.

Among the strangers whom he received under his roof, there were some who returned his kindness with ingratitude. Among these was Paul Witichius, a mathematician; who, under the pretence of devoting his whole life to astronomy, insinuated himself into the utmost familiarity with Tycho. The unsuspecting astronomer explained to his guest all his inventions, described all his methods, and even made him acquainted with those views which he had not realised, and with instruments which he had not yet executed. When Witichius had thus obtained possession of the methods, and inventions, and views of Tycho, and had enjoyed his hospitality for three months, he pretended that he was obliged to return to Germany to receive an inheritance to which he had succeeded. After quitting Uraniburg, this ungrateful mathematician neither returned to see Tycho, nor kept up any correspondence with him; and it was not till five years after his departure that Tycho learned, from the letters of the Prince of Hesse to Ranzau, that Witichius had passed through Hesse, and had described, as his own, the various inventions and methods which had been shewn to him in Huen.

Being unable to reconcile his own observations with those of Copernicus, and with the Prutenic Tables, Tycho resolved to obtain new determinations of the latitude of Frauenburg, in Prussia, where Copernicus made his observations, and of Konigsberg, to the meridian of which Rheinhold had adapted his Prutenic Tables. For these purposes he sent one of his assistants, Elias Morsianus, with a proper instrument, under the protection of Bylovius, Ambassador of the Margrave of Anspach, to the King of Denmark, who was returning by sea to Germany; and after receiving the greatest attention and assistance from the noble Canons of Ermeland, he determined, from nearly a month's observations on the sun and stars, that the latitude of Frauenburg was 54 deg. 22-1/2', in place of 54 deg. 19-1/2', as given by Copernicus. In like manner he determined that the latitude of Konigsberg was 54 deg. 43', in place of 54 deg. 17', as adopted by Rheinhold. When Morsianus returned to Huen in July, he brought with him, as a present to Tycho, from John Hannovius, one of the Canons of Ermeland, the Ptolemaic Rules, or the Parallactic Instrument which Copernicus had used and made with his own hands. It consisted of two equal wooden rules, five cubits long, and divided into 1414 parts. Tycho preserved this gift as one peculiarly dear to him, and, on the day of his receiving it, he composed a set of verses in honour of the great astronomer to whom it belonged.

Among the distinguished visits which were paid to Tycho, we must enumerate that of Ulric, Duke of Mecklenburg, in 1586. Although his daughter, Sophia, Queen of Denmark, had already paid two visits to Uraniburg in the same year, yet such was her love of astronomy, that she accompanied her father and his wife Elizabeth on this occasion. Ulric was not only fond of science in general, but had for many years devoted himself to chemical pursuits, and he was therefore peculiarly gratified in examining the splendid laboratory and extensive apparatus which Tycho possessed. It has been said by some of the biographers of Tycho, that the Landgrave of Hesse visited Uraniburg about this period; but this opinion is not correct, as it was only his astronomer and optician, Rothman, who made a journey to Huen in 1591 for the recovery of his health. Tycho had long carried on a correspondence with this able astronomer respecting the observations made at the observatory of Hesse-Cassel, and, during the few months which they now spent together, they discussed in the amplest manner all the questions which had previously been agitated. Rothman was astonished at the wonderful apparatus which he saw at Uraniburg, and returned to his native country charmed with the hospitality of the Danish astronomer.

Hitherto we have followed Tycho through a career of almost unexampled prosperity. When he had scarcely reached his thirtieth year he was established, by the kindness and liberality of his sovereign, in the most splendid observatory that had ever been erected in Europe; and a thriving family, an ample income, and a widely extended reputation were added to his blessings. Of the value of these gifts he was deeply sensible, and he enjoyed them the more that he received them with a grateful heart. Tycho was a christian as well as a philosopher. The powers of his gifted mind have been amply displayed in his astronomical labours; but we shall now have occasion to witness his piety and resignation in submitting to an unexpected and an adverse destiny.



CHAPTER III.

Tycho's Labours do honour to his Country—Death of Frederick II.—James VI. of Scotland visits Tycho at Uraniburg—Christian IV. visits Tycho—The Duke of Brunswick's visit to Tycho—The Danish Nobility, jealous of his fame, conspire against him—He is compelled to quit Uraniburg—And to abandon his Studies—Cruelty of the Minister Walchendorp—Tycho quits Denmark with his Family and Instruments—Is hospitably received by Count Rantzau—Who introduces him to the Emperor Rudolph—The Emperor invites him to Prague—He gives him a Pension of 3000 Crowns—And the Castle of Benach as a Residence and an Observatory—Kepler visits Tycho—Who obtains for him the Appointment of Mathematician to Rudolph.

The love of astronomy which had been so unequivocally exhibited by Frederick II. and his Royal Consort, inspired their courtiers with at least an outward respect for science; and among the ministers and advisers of the King, Tycho reckoned many ardent friends. It was every where felt that Denmark had elevated herself among the nations of Europe by her liberality to Tycho; and the peaceful glory which he had in return conferred upon his country was not of a kind to dissatisfy even rival nations. In the conquests of science no widow's or orphan's tears are shed, no captives are dragged from their homes, and no devoted victims are yoked to the chariot wheels of the triumphant philosopher. The newly acquired domains of knowledge belong, in right of conquest, to all nations, and Denmark had now earned the gratitude of Europe by the magnitude as well as the success of her contingent.

An event, however, now occurred which threatened with destruction the interests of Danish science. In the beginning of April 1588, Frederick II. died in the 54th year of his age, and the 29th of his reign. His remains were conveyed to Rothschild, and deposited in the chapel under Tycho's care, where a finely executed bust of him was afterwards placed. His son and successor, Christian IV., was only in the 11th year of his age, and though his temper and disposition were good, yet Tycho had reason to be alarmed at the possibility of his discontinuing the patronage of astronomy. The taste for science, however, which had sprung up in the Danish Court had extended itself no wider than the influence of the reigning sovereign. The parasites of royalty saw themselves eclipsed in the bright renown which Tycho had acquired, and every new visit to Uraniburg by a foreign prince supplied fresh fuel to the rancour which had long been smothering in their breasts. The accession of a youthful king held out to his enemies an opportunity of destroying the influence of Tycho; and though no adverse step was taken, yet he had the sagacity to foresee, in "trifles light as air," the approaching confirmation of his fears. Hope, however, still cheered him amid his labours, but that hope was founded chiefly on the learning and character of Nicolas Caasius, the Chancellor of the Kingdom, from whom he had experienced the warmest attentions.

Among the princes who visited Uraniburg, there were none who conducted themselves with more condescension and generosity than our own sovereign, James VI. In the year 1590, when the Scottish King repaired to Denmark to celebrate his marriage with the Princess Anne, the King's sister, he paid a visit to Tycho, attended by his councillors and a large suite of nobility. During the eight days which he spent at Uraniburg, James carried on long discussions with Tycho on various subjects, but chiefly on the motion which Copernicus had ascribed to the earth. He examined narrowly all the astronomical instruments, and made himself acquainted with the principles of their construction and the method of using them. He inspected the busts and pictures in the museum, and when he perceived the portrait of George Buchanan, his own preceptor, he could not refrain from the strongest expressions of delight. Upon quitting the hospitable roof of Tycho, James not only presented him with a magnificent donation, but afterwards gave him his royal license to publish his works in England during seventy years. This license was accompanied with the following high eulogium on his abilities and learning:—"Nor have I become acquainted with these things only from the relation of others, or from a bare inspection of your works, but I have seen then before my own eyes, and have heard them with my own ears, in your residence at Uraniburg, and have drawn them from the various learned and agreeable conversations which I there held with you, and which even now affect my mind to such a degree, that it is difficult to determine whether I recollect them with greater pleasure or admiration; as I now willingly testify, by this license, to present and to future generations," &c.

At the request of Tycho, the King also composed and wrote in his own hand some Latin verses, which were more complimentary than classical. His Chancellor had also composed some verses of a similar character during his visit to Tycho. A short specimen of these will be deemed sufficient by the classical reader:—

"Vidit et obstupuit Rex Huennum Scoticus almam; Miratus clari tot monumenta viri."

In the year 1591, when Christian IV. had reached his 14th year, he expressed a desire to pay a visit to Uraniburg. He accordingly set out with a large party, consisting of his three principal senators, and other councillors and noblemen; and having examined the various instruments in the observatories and laboratory, he proposed to Tycho various questions on mechanics and mathematics, but particularly on the principles of fortification and ship building. Having observed that he particularly admired a brass globe, which, by means of internal wheelwork, imitated the diurnal motion of the heavens, the rising and setting of the sun, and the phases of the moon, Tycho made him a present of it, and received in return an elegant gold chain, with his Majesty's picture, with an assurance of his unalterable attachment and protection.

Notwithstanding this assurance, Tycho had already, as we have stated, begun to suspect the designs of his enemies; and in a letter addressed to the Landgrave of Hesse, early in 1591, he throws out some hints which indicated the anxieties that agitated his mind. The Landgrave of Hesse, as if he had heard some rumours unfavourable to the prospects of Tycho, requested him to write him respecting the state of the Kingdom, and concerning his own private affairs. To this letter, which was dated early in February, Tycho replied about the beginning of April. He informed the Landgrave that he led a private life in his own island, exempt from all official functions, and never willingly taking a part in public affairs. He was desirous of leaving the ambition of public honours to others, and of devoting himself wholly to the study of philosophy and astronomy; and he expressed a hope that if he should be involved in the tumults and troubles of life, either by his own destiny or by evil counsels, he might be able, by the blessing of God, to extricate himself by the force of his mind and the integrity of his life. He comforted himself with the idea that every soil was the country of a great man, and that wherever he went the blue sky would still be over his head;[40] and he distinctly states at the close of his letter, that he had thought of transferring his residence to some other place, as there were some of the King's councillors who had already begun to calumniate his studies, and to grudge him his pension from the treasury.

[40] Omne solum forti patria, et coelum undique supra est.

The causes which led to this change of feeling on the part of Christian IV.'s advisers have not been explained by the biographers of Tycho. It has been stated, in general terms, that he had made many enemies, by the keenness of his temper and the severity of his satire; but I have not been able to discover any distinct examples of these peculiarities of his mind. In an event, indeed, which occurred about this time, he slightly resented a piece of marked incivility on the part of Henry Julius, Duke of Brunswick, who had married the Princess Eliza of Denmark; but it is not likely that so trivial an affair, if it were known at court, could have called down upon him the hostility of the King's advisers.

The Duke of Brunswick had, in 1590, paid a visit to Uraniburg, and had particularly admired an antique brass statue of Mercury, about a cubit long, which Tycho had placed in the roof of the hypocaust or central crypt of the Stiern-berg observatory. By means of a concealed mechanism, it moved round in a circular orbit. The Duke requested the statue and its machinery, which Tycho gave him, on the condition that he should obtain a model of it, for the purpose of having another executed by a skilful workman. The Duke not only forgot his promise, but paid no attention to the letters which were addressed to him. Tycho was justly irritated at this unprincely conduct, and ordered this anecdote to be inserted in the description of Uraniburg which he was now preparing for publication.

In the year 1592, Tycho lost his distinguished friend and correspondent the Prince of Hesse, and astronomy one of its most active and intelligent cultivators. His grief on this occasion was deep and sincere, and he gave utterance to his feelings in an impassioned elegy, in which he recorded the virtues and talents of his friend. Prince Maurice, the son and successor of the Landgrave, continued, with the assistance of able observers, to keep up the reputation of the observatory of Hesse-Cassel; and the observations which were there made were afterwards published by Snellius. The extensive and valuable correspondence between Tycho and the Landgrave was prepared for publication about the beginning of 1593, and contains also the letters of Rothman and Rantzau.