LIVES

OF

EMINENT

LITERARY AND SCIENTIFIC MEN.

GALILEO.

1564-1642.

THE history of the life and labours of Galileo is pregnant with a peculiar interest to the general reader, as well as to the philosopher. His brilliant discoveries, the man of science regards as his peculiar property; the means by which they were made, and the developement of his intellectual character, belong to the logician and to the philosopher; but the triumphs and the reverses of his eventful life must be claimed for our common nature, as a source of more than ordinary instruction.

The lengthened career which Providence assigned to Galileo was filled up throughout its rugged outline with events even of dramatic interest. But though it was emblazoned with achievements of transcendent magnitude, yet his finest discoveries were the derision of his contemporaries, and were even denounced as crimes which merited the vengeance of Heaven. Though he was the idol of his friends, and the favoured companion of princes, yet he afterwards became the victim of persecution, and spent some of his last hours within the walls of a prison; and though the Almighty granted

him, as it were, a new sight to descry unknown worlds in the obscurity of space, yet the eyes which were allowed to witness such wonders, were themselves doomed to be closed in darkness.

Such were the lights' and shadows in which history delineates

"The starry Galileo with his woes."

But, however powerful be their contrasts, they are not unusual in their proportions. The balance which has been struck between his days of good and evil, is that which regulates the lot of man, whether we study it in the despotic sway of the autocrat, in the peaceful enquiries of the philosopher, or in the humbler toils of ordinary life.

Galileo Galilei was born at Pisa, on the 15th of February, 1564, and was the eldest of a family of three sons and three daughters. Under the name of Bonajuti, his noble ancestors had filled high offices at Florence; but about the middle of the 14th century they seem to have abandoned this surname for that of Galileo. Vincenzo Galilei, our author's father, was himself a philosopher of no mean powers; and though his talents seem to have been applied only in the composition of treatises on the theory and practice of music, yet he appears to have anticipated even his son in a just estimate of the philosophy of the age, and in a distinct perception of the true method of investigating truth.+

The early years of Galileo were, like those of almost all great experimental philosophers, spent in the construction of instruments and pieces of machinery, which were calculated chiefly to amuse himself and his schoolfellows. This occupation of his hands, however, did not interfere with his regular studies; and though, from the straitened circumstances of his father, he was educated under considerable disadvantages, yet he acquired the elements of classical literature, and was initiated into all the learning of the times. Music, drawing, and paint

Childe Harold, canto iv. stanza liv.

+ Life of Galileo, Library of Useful Knowledge, p. 1.

ing were the occupations of his leisure hours; and such was his proficiency in these arts, that he was reckoned a skilful performer on several musical instruments, especially the lute; and his knowledge of pictures was held in great esteem by some of the best artists of his day.

Galileo seems to have been desirous of following the profession of a painter: but his father had observed decided indications of early genius; and, though by no means able to afford it, he resolved to send him to the university to pursue the study of medicine. He accordingly enrolled himself as a scholar in arts at the university of Pisa, on the 5th of November, 1581, and pursued his medical studies under the celebrated botanist Andrew Casalpinus, who filled the chair of medicine from 1567 to 1592.

In order to study the principles of music and drawing, Galileo found it necessary to acquire some knowledge of geometry. His father seems to have foreseen the consequences of following this new pursuit, and though he did not prohibit him from reading Euclid under Ostilio Ricci, one of the professors at Pisa, yet he watched his progress with the utmost jealousy, and had resolved that it should not interfere with his medical studies. The demonstrations, however, of the Greek mathematician had too many charms for the ardent mind of Galileo. His whole attention was engrossed with the new truths which burst upon his understanding; and after many fruitless attempts to check his ardour and direct his thoughts to professional objects, his father was obliged to surrender his parental control, and allow the fullest scope to the genius of his son.

From the elementary works of geometry, Galileo passed to the writings of Archimedes; and while he was studying the hydrostatical treatise of the Syracusan philosopher, he wrote his essay on the hydrostatical balancet, in which he describes the construction of the instrument, and the method by which Archimedes detected the fraud committed by the jeweller

De Insidentibus in Fluido.

+ Opere di Galileo. Milano, 1810, vol. iv. p. 243-257.

in the composition of Hiero's crown. This work gained for its author the esteem of Guido Ubaldi, who had distinguished himself by his mechanical and mathematical acquirements, and who engaged his young friend to investigate the subject of the centre of gravity in solid bodies. The treatise on this subject, which Galileo presented to his patron, was the source of his future success.

Through the cardinal del Monte, the brother-in-law of Ubaldi, the reigning duke of Tuscany, Ferdinand de’ Medici, was made acquainted with the merits of our young philosopher; and, in 1589, he was appointed lecturer on mathematics at Pisa. By the drudgery of private teaching he was obliged to add to the small salary of sixty crowns which was attached to the office.

With this moderate competency, Galileo commenced his philosophical career. At the early age of eighteen, when he had entered the university, he displayed his innate antipathy to the Aristotelian philosophy. This feeling was strengthened by his earliest inquiries; and upon his establishment at Pisa, he seems to have regarded the doctrines of Aristotle as the intellectual prey which, in his chace of glory, he was destined to pursue. Nizzoli, who flourished near the beginning of the sixteenth century, and Giordano Bruno, who was burned at Rome in 1600, led the way in this daring pursuit; but it was reserved for Galileo to track the Thracian boar through its native thickets, and, at the risk of his own life, to strangle it in its den.

With the resolution of submitting every opinion to the test of experiment, Galileo's first inquiries at Pisa were directed to the mechanical doctrines of Aristotle. Their incorrectness and absurdity soon became apparent; and with a zeal, perhaps, bordering on indiscretion, he denounced them to his pupils with an ardour of manner and of expression proportioned to his own conviction of the truth. The detection of long-established errors is apt to inspire the young philosopher with an exultation which reason condemns. The feeling of triumph is apt to clothe itself in the language of asperity; and the

abettor of erroneous opinions is treated as a species of enemy to science. Like the soldier who fleshes his first spear in battle, the philosopher is apt to leave the stain of cruelty upon his early achievements. It is only from age and experience, indeed, that we can expect the discretion of valour, whether it is called forth in contro

versy or in battle. Galileo seems to have waged this stern warfare against the followers of Aristotle; and such was the exasperation which was excited by his reiterated and successful attacks, that he was assailed, during the rest of his life, with a degree of rancour which seldom originates in a mere difference of opinion. Forgetting that all knowledge is progressive, and that the errors of one generation call forth the comments, and are replaced by the discoveries, of the next, Galileo did not anticipate that his own speculations and incompleted labours might one day provoke unmitigated censure; and he therefore failed in making allowance for the prejudices and ignorance of his opponents. He who enjoys the proud lot of taking a position in advance of his age, need not wonder that his less gifted contemporaries are left behind. Men are not necessarily obstinate because they cleave to deeply rooted and venerable errors, nor are they absolutely stupid when they are long in understanding and embracing newly discovered truths.

It was one of the axioms of the Aristotelian mechanics, that the heavier of two falling bodies would reach the ground sooner than the other, and that their velocities would be proportional to their weights. Galileo attacked the arguments by which this opinion was supported; and when he found his reasoning ineffectual, he appealed to direct experiment. He maintained, that all bodies would fall through the same height in the same time, if they were not unequally retarded by the resistance of the air: and though he performed the same experiment with the most satisfactory results, by letting heavy bodies fall from the leaning tower of Pisa; yet the Aristotelians, who with their own eyes saw the unequal weights strike the ground