The Martyrs of Science, or, The lives of Galileo, Tycho Brahe, and Kepler Part 4

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 ma.s.s during pa.s.sion 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 amba.s.sador 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 amba.s.sador 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 princ.i.p.ally 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 amba.s.sador 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 amba.s.sador.

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 lat.i.tude, 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 antic.i.p.ated 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 s.p.a.ce which I myself occupy. So it pleases G.o.d; it shall, therefore, please me also." His friend, Father Castelli, deplores the calamity in the same tone of pathetic sublimity:--"The n.o.blest 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 ill.u.s.trious 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 a.s.sured him, that if his plan should prove successful it should not pa.s.s 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 a.s.sembled 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 ma.n.u.scripts of Galileo, which he was on the eve of publis.h.i.+ng, 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 Ga.s.sendi, Deodati, and our ill.u.s.trious 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.

c.u.m 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 sec.u.m tulit, quam reliquit.

Gravi enim Sed nondum affecta senectute, Novis contemplationibus Majorem gloriam affectans Inexplebilem sapientiae animam Immaturo n.o.bis 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 n.o.ble 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 superst.i.tion, 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 a.s.sists 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 Ca.s.siopeia--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 n.o.ble Swedish family, was in such straitened circ.u.mstances, 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 ent.i.tled 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 a.s.sistance 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 compa.s.s, 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 a.s.sist 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 circ.u.mstances 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 n.o.ble 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 cla.s.ses, 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 coa.r.s.e 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 princ.i.p.al 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 bra.s.s, 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 alt.i.tude 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 s.p.a.ce of five years.

As this quadrant was fitted only to determine the alt.i.tudes of the celestial bodies, Tycho constructed a large s.e.xtant 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 ma.s.sacre 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 s.e.xtant which he had given him in a present. He paid a visit to Philip Appian in pa.s.sing 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 a.s.signed 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 s.p.a.cious 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 const.i.tuted 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 surpa.s.sing 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 s.e.xtants for his crucibles. In order, however, that he might have one good instrument in his observatory, he constructed a s.e.xtant similar to, but somewhat larger than, that which he had presented to Hainzel. Its limb was made of solid bra.s.s, and was exquisitely divided into single minutes of a degree. Its radii were strengthened with plates of bra.s.s, 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 Ca.s.siopeia, 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 s.e.xtant, and measured its distances from the nearest stars in Ca.s.siopeia. 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.