GALILEO. -(1564-1641.)

Vincenzo Galilei and Julia Ammanati of Pistoja in Tuscany, were the parents of Galileo Galilei, who was born at Pisa on the 15th of February, 1564. His introduction to science was through poetry, music, and the plastic arts, but when he had once begun to study science he regarded the fine arts as no more than a relaxation from arduous labor. His father being anxious that he should become a doctor, he matriculated at the University of Pisa in 1581, and attended the medical lectures of Andrea Cesalpino, but having been accidentally led to study mathematics he acquired such proficiency in that science that in 1589 he was appointed professor at Pisa. Private misunderstandings induced him, however, to remove to Padua, where during eighteen years he filled the chair of astronomical sciences. Florence, in the meanwhile, was very anxious to secure his services, and Cosimo II. appointed him his philosopher and mathematician, supplying him with ample means for devoting himself to the speculative inquiries and costly experiments which his researches necessitated.

His astronomical studies involved him in persecution and suffering, for in propagating the system of Copernicus the theologians accused him of teaching doctrines opposed to the Bible, and a Florentine monk hurled against him from the pulpit the passage from the Acts of the Apostles, " Ye men of Galilee, why stand ye gazing up into heaven?" The noise of all this travelled from Florence to Rome, and the Grand Duke, who was obliged to show deference to the Vatican, advised Galileo to appear before the Inquisition and defend himself against such a false accusation. He arrived at Rome in 1615, but in spite of the ability with which he argued that his doctrines were orthodox, he made no impression upon the tribunal, which had made up its mind to condemn him. He was, however, allowed to go free upon condition that he did not teach the doctrine of Copernicus, and it was subsequent to this that he wrote his "Dialogues," and submitted them to the censorship of the Vatican, obtaining the official sanction and printing them in 1632.

After an interval of seventeen years, from the time when Cardinal Bellarmino, in the name of the Pontiff, had forbidden him to propagate his doctrines, he was again summoned to appear before the Inquisition. He was not treated as an ordinary prisoner, and the Grand Duke, full of solicitude for his welfare, did all that he could to shield him from the possible consequences of the dreaded summons. He was lodged at first with the procurator-fiscal of the Holy Office, and then he was allowed to reside at the house of the Florentine ambassador, while at last he was permitted to go about the city upon parole. The trial lasted two months, and it ended in a retractation, followed by a sentence of imprisonment in the dungeons of the Inquisition. Urban VIII., however, commuted the punishment, and allowed him to live first at the Villa Medici, afterwards in the archbishop's palace at Siena, and finally in his own villa at Areetri, near Florence. In 1637 he became blind, but he continued to give lessons to the many devoted students of science whom he had gathered around him, seated on the terrace of the villa where he had spent so many nights watching the heavens. Fully resigned to his lot, and venerated as much for his misfortunes as for his genius, he received frequent visits from Cardinal Leopold and the Grand Duke Ferdinand. He died on the 18th of January, 1641, aged seventy-seven, and his body was interred with great pomp in Santa Croce, the monument erected to his memory being close to that of Michael Angelo. He was the inventor of the microscope, the thermometer, the sector, and the small hydrostatic balance. It has been denied that he invented the telescope, but in my previous work, " Venice," I have given the official report of the sitting of the Senate at which he made the experiments for which he received a pension from the Republic, already much indebted to him for his seventeen years' professorship at the University of Padua. The probability is, however, that he merely made a practical application of an invention due to Jacobus Mebius, an inhabitant of Holland, adapting the glasses made by the latter to tubes which enabled him to make astronomical observations. He also invented the pendulum, and in a letter to Lorenzo Redi, still extant, he explained how it might be adapted to clocks. His labors in the domain of astronomical science were almost boundless. He brought into clear relief the system of gravitation, explained the formation of the Milky Way, discovered the stars which accompany Saturn, and having ascertained the existence of satellites to Jupiter, named them " Medici stars," and made a careful calculation of their periods. He was the first to discover the unevenness of the moon's surface, its diameter, and the great altitude of its mountains. He also pointed out the spots on the sun, and explained the character of them.

In physical science his researches were also very extensive, and he proved that a mote of straw and a piece of lead fall at an equal rate when the air is rarefied. The pneumatic machine was invented to prove this law of nature, and the demonstration was most convincing. He laid down the law as to the acceleration of weighty substances, and reduced to fixed and certain principles their descent along inclined planes. He devoted a great deal of time also to hydrostatics and to hydraulics, though the only treatise which he wrote about them is that comprised in some correspondence concerning the overflow of the river Bisentio, near Florence.

In the course of a recent debate in the French Chamber of Deputies it was alleged that Galileo had never been persecuted, but Signor Domenico Berti has published an official report of his trial, with the documents preserved in the State archives at Rome.