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Dutchman, had invented a glass by means of explanations, but was directly accused of hewhich distant objects appeared as if they were resy for maintaining the two propositions, that near, he turned his attention to this subject, and the sun is the centre of the world, and imfrom the imperfect accounts which he had re- moveable by a local motion ; and that the earth ceived, and his own reflections on the nature of is not the centre of the world, nor immoverefraction, discovered the construction of that able, but moves with a diurnal motion. These instrument. The next day, after he had solved propositions he was by a decree of the Inquisithe problem of its construction, he made such tors ordered to renounce, and not to defend an instrument, and by the attention which he them either in conversation or writing, or even paid to its perfection and improvement, may to insinuate them into the minds of any persons justly be considered as the second inventor of whomsoever. Most accounts concur in stating, the telescope. He now turned his instrument that on this occasion he was committed to the towards the heavens, and discovered unheard-of prison of the holy office, where he was confined wonders. He perceived the surface of the moon for about five months ; but according to other not to be smooth, but rough, and full of pro- accounts he was treated with greater mildness, minences and cavities. The milky-way he and only threatened with imprisonment if he found to be an assemblage of fixed stars, invi- should prove refractory. Be that as it may, he sible to the naked eye. Venus he found to was not permitted to quit Rome until he had vary in its phases like the moon. The figure of promised to conform himself to the decree of Saturn he observed to be oblong, and imagined the Inquisition ; and it is probable that his senthat it consisted of three distinct parts, one tence would have been more severe, had not spherical in the midst, and two lesser ones on the grand-duke of Tuscany warmly interested the sides, which afterwards appeared to be only himself on his behalf, as well as some persons the anse, or extreme parts of Saturn's ring. Ju- of high rank and influence at the papal court. piter he saw surrounded with four moons, Galileo now returned to his studies, in which which in honour of the duke de Medici he called his astronomical observations and other happy Medicean stars, and soon perceived that by discoveries served to establish most completely means of their frequent eclipses geographical and satisfactorily the truth of his obnoxious longitudes might be found. On the sun's disk opinions. From time to time he laid before the he perceived spots, from the motion of which public an account of his discoveries, with such he inferred that the sun revolved on its axis. remarks and inferences as tended to point out It was while he was pursuing these discoveries, the natural conclusions to be drawn from them. that he was invited to Florence, where, as we At length, in the year 1632, he ventured to have seen, he had leisure afforded him to devote publish at Florence his famous “ Dialogues on himself to his mathematical and philosophical the two greatest Systems of the World, the studies, without being obliged to attend to the Ptolemaic and Copernican;" in which he produties of his professorship. In a very few years, duced the strongest arguments in favour of both however, his tranquillity was disturbed by the systems, without expressing a decided opinion ignorant and bigotted clergy, on account of the which of them was the true one, but not withzeal which he discovered for illustrating and out such insinuations in favour of the Copernican confirming the truth of the Copernican system. as sufficiently indicated its superior reasonableThat system they maintained to be false and ness, and his own belief in it. These dialogues, heretical, as being contrary to the plain and ex- likewise, contain some keen strokes of raillery press language of the Scriptures, and by their against the Aristotelians, for their bigotted and complaints against him to the Inquisition at servile attachment to every hypothesis of their Rome, rendered it necessary for him, in the master. Scarcely had this work made its apyear 1615, to appear in that city to justify him- pearance, before the cry of heresy was raised self. According to letters written from Rome more loudly than ever against Galileo, and he by the learned Anthony Querenghi, Galileo was again cited to appear before the tribunal of did not lose his courage on this occasion, but the Inquisition, in the year 1633. Though in numerous companies of men of letters and now seventy years of age, he was obliged to others, defended the Copernican doctrine with submit to the persecuting mandate, and on his a force of argument which persuaded many of arrival at Rome was at first committed prisoner its truth and reasonableness, and silenced the to the apartments of the fiscal of the holy of. objections of others who would not be con- fice. Afterwards, through the intercession of vinced. When he attended the Inquisition, the grand-duke, he was permitted to reside in however, he was not suffered to enter into any the house of his embassador while the process

mpanies of men doctrine with arrival at Romentos comphe Coperniersuaded many the to the afterwards,

was carrying on against him. After his trial observes, there had been nothing done in mehad lasted about two months, he was brought chanical geometry, till Galileo, who possessed up to receive sentence in full congregation; an excellent judgment, and great skill in the when he was ordered, in the most solemn man- most abstruse points of geometry, first extend. ner, to abjure and condemn the Copernican ed the boundaries of that science, and began to system, as contrary to the Scriptures, and to reduce the resistance of solid bodies to its laws. bind himself by oath no longer to teach or sup- We shall follow the example of Dr. Hutton, in port it, either directly or indirectly. As a pu- giving a summary sketch of his discoveries and nishment for having disobeyed the former de- improvements, chiefly in the language of the cree of the court, he was condemned to be de- judicious Colin Maclaurin. “ He made the tained in the prisons of the holy office, during evidence of the Copernican system more senthe pleasure of the cardinal inquisitors; and en- sible, when he shewed from the phases of Vejoined as a saving penance, for three years to nus, like to the monthly phases of the moon, come, to repeat once a-week the seven peni- that Venus actually revolves about the sun. He tential psalms, the court reserving to them- proved the revolution of the sun on his axis, selves the power of moderating, changing, and from his spots; and thence the diurnal rotation taking away, altogether, or in part, the above- of the earth became more credible. The four mentioned punishment and penance. His satellites that attended Jupiter in his revolution “ Dialogues" were also censured, prohibited, about the sun, represented, in Jupiter's lesser and ordered to be burnt at Rome. Pope Ur- system, a just image of the great solar system; ban VIII., who at that time sat on the pontific and rendered it more easy to conceive how the cal throne, lessened the rigour of his sentence, moon night attend the earth, as a satellite, in by confining him for a time to the palace and her annual revolution. By discovering hills and garden de Medici at Rome ; after which he was cavities in the moon, and spots in the sun consent to the archiepiscopal palace at Sienna, stantly varying, he shewed that there was not where the air was more favourable to his state so great a difference between celestial and subof health; and in the course of the year 1634 lunary bodies as the philosophers had vainly he was permitted to reside at his country-house imagined. He rendered no less service to sci. at Arcetri, in the vicinity of Florence. In this ence by treating, in a clear and geometrical place he spent the remainder of his days, visited manner, the doctrine of motion, which has and esteemed by the most distinguished cha- been justly called the Key of Nature. The racters in Florence, and diligently applying rational part of mechanics had been so much himself to his celestial observations. By his neglected, that scarcely any improvement was continual use of the telescope, however, and made in it for almost two thousand years; but the injuries which his eyes received from the Galileo has given us fully the theory of equable nocturnal air, his sight was gradually impaired, motions, and of such as are uniformly accelertill he became entirely blind about three years ated or retarded, and of these two compounded before his death. This calamity he bore with a together. He, first, demonstrated, that the truly philosophical resignation, employing him- spaces described by heavy bodies from the beself in constant meditation and enquiry, the re- ginning of their descent are as the squares of sult of which he intended to communicate to the times; and that a body, projected in any the world. He had digested much matter, and direction that is not perpendicular to the hori had begun to dictate his conceptions, when he zon, describes a parabola. These were the bewas attacked by a distemper which terminated ginnings of the doctrine of the motion of heavy in his death, in 1642, when he was in the se- bodies, which has been since carried to so great venty-eighth year of his age. Galileo was small a height by sir Isaac Newton. In geometry, he in stature, but of a venerable aspect, and of a invented the Cycloid, or Trochoid; though the vigorous constitution. His learning was very properties of it were afterwards chiefly demonextensive ; and he possessed in a high degree, a strated by his pupil Torricelli. He invented clearness and acuteness of wit. In company the simple pendulum, and made use of it in his he was free and affable, and full of pleasantry, astronomical experiments: he had also thoughts He took great delight in architecture and paint- of applying it to clocks; but did not execute ing, and designed extremely well ; and he also that design. The glory of that invention was played on the lute with great skill and taste, reserved for his son Vincenzo, who made the Whenever he spent any part of his time in the experiment at Venice in 1649 ; and Huygens country, he took great pleasure in husbandry. afterwards carried the invention to perfection. From the time of Archimedes, as M. Leibnitz Of Galileo's invention also was the inachine with which the Venetians render their Laguna 1623; “ A Letter to Prince Leopold of Tusfluid and navigable. He also discovered the cany, examining the fiftieth Chapter of Licegravity of the air, and endeavoured to compare tus's Letheosphoros ;'' “ A Letter to Christopher it with that of water; and opened up several Greinbergerus, concerning the Montuosity of other enquiries in natural philosophy. He was the Moon,” 1611 ; “Mathematical Discourses not esteemed and followed by philosophers only, and Demonstrations concerning two new Scibut was honoured by persons of the greatest dis- ences, relating to Mechanics and local Motions, tinction of all nations. Galileo had scholars together with an Appendix concerning the worthy of so great a master, by whom the gra- Centre of Gravity in some Solids," 1638, &c. vitation of the atmosphere was established fully, The preceding articles, together with some and its varying pressure accurately and conve- other treatises written either by Galileo, or by niently measured, by the column of quick- some of his disciples in defence of his doctrines .silver of equal weight sustained by it in the and observations, were collected and publishbarometrical tube. The elasticity of the air, by ed by Menolessi, in 1656, under the title of which it perpetually endeavours to expand itself, “ L'Opere de Galileo Galilei Lynceo, nobile and, while it admits of condensation, resists in Fiorentino, &c.” in two volumes quarto. Se proportion to its density, was a phenomenon of veral of these pieces were translated into Enga new kind (the common fluids having no such lish, and published by Thomas Salisbury, in his property), and of the utmost importance to phi- “ Mathematical Collections,” in two volumes losophy. These principles opened a vast field folio. A volume also of his “ Letters" to seof new and useful knowledge, and explained a veral learned men, and solutions of a variety of great variety of phenomena, which had been ac- problems, was published at Bologna, in quarto. counted for in an absurd manner before that His last disciple, Vincenzo Viviani, who proved time. It seemed as if the air, the fluid in which a very eminent mathematician, methodised a men lived from the beginning, had been then piece of his master's, and published it under the first discovered. Philosophers were every- title of “ Quinto Libro de gli Elementi d'Euwhere busy enquiring into the various properties clide, &c." 1674, quarto ; and he also puband their effects; and valuable discoveries re- lished some other pieces of Galileo, including warded their industry. Of the great number extracts from his Letters to a learned Frenchwho distinguished themselves on this occasion, man, in which the author gives an account of we cannot but mention Torricelli and Viviani the works which he intended to have published, in Italy, Pascal in France, Otto Guerick in and an extract of a Letter to John Camillo, a Germany, and Boyle in England.” Galileo mathematician of Naples, concerning the angle wrote a number of treatises, of which the prin- of contact. Many other of Galileo's writings cipal, published during his life-time, besides were unfortunately lost to the world, owing to his “ Mechanics," “ Balance,” and “ Dia- the superstition of one of his ignorant nephews; 'logues,” already mentioned, were, “ The Ope- who, considering that his uncle died a prisoner

rations of the Compass, geometrical and mili- of the holy office, though permitted to reside 'tary," 1606; “ A Discourse addressed to the in his own house, suspected that his papers most serene, Cosmo II., Grand-duke of Tus- might contain dangerous heresies, and therecany, concerning the Swimming of Bodies upon, fore committed them to the flames. Sir John and their Submersionin, Water," 1612;“Nun- Finch, in a Letter to Thomas Salisbury, attri'cius Sidereus," 1610, of which “ A Continua- butes the destruction of Galileo's MSS. to his tion,” or “ An Essay on the History of Gali- widow's devotion, and the fanaticism of her leo's last Observations on Saturn, Mirs, Venus, confessor; but the best authorities maintain that and the Sun, &c.” was afterwards collected our philosopher was never married. His son from letters between Galileo and his corre- VINCENZO GALILEI, who, as we have already spondents; “ A Letter concerning the Trepida- seen, honourably supported his father's repution of the Moon, lately discovered, inscribed tation, by first applying his invention of the to Alphonso Antonini, with Antonini's An- pendulum to clock-work,, was of illegitimate swer,” 1638; “ A Discourse of the solar Spots, birth.

&c. with Predictions and Ephemerides of the Vincenzo GALILEI, the father of Galileo, Medicean Planets,” 1613; the famous Italian was a man of letters, not unskilled in the mapiece entitled “ Il Saggiatore," written in de thematics, and particularly conversant in the fence of Guiducci's - Discourse on Comets," science of music. He wrote some elaborate and containing a complete account of the physi- works, of which the most esteemed consist of ology and astronomy of our author, printed in five dialogues concerning harmony, and its

was carrying on against him. After his trial observes, there had been nothing done in mehad lasted about two months. he was brought chanical geometry, till Galileo, who possessed up to receive sentence in full congregation; an excellent judgment, and great skill in the when he was ordered, in the most solemn man- most abstruse points of geometry, first extend. ner, to abjure and condemn the Copernican ed the boundaries of that science, and began to system, as contrary to the Scriptures, and to reduce the resistance of solid bodies to its laws. bind himself by oath no longer to teach or sup- We shall follow the example of Dr. Hutton, in port it, either directly or indirectly. As a pu- giving a summary sketch of his discoveries and nishment for having disobeyed the former de- improvements, chiefly in the language of the cree of the court, he was condemned to be de- judicious Colin Maclaurin. “ He made the tained in the prisons of the holy office, during evidence of the Copernican system more senthe pleasure of the cardinal inquisitors; and en- sible, when he shewed from the phases of Vejoined as a saving penance, for three years to nus, like to the monthly phases of the moon, come, to repeat once a-week the seven peni- that Venus actually revolves about the sun. He tential psalms, the court reserving to them- proved the revolution of the sun on his axis, selves the power of moderating, changing, and from his spots; and thence the diurnal rotation taking away, altogether, or in part, the above- of the earth became more credible. The four mentioned punishment and penance. His satellites that attended Jupiter in his revolution “ Dialogues" were also censured, prohibited, about the sun, represented, in Jupiter's lesser and ordered to be burnt at Rome. Pope Ur- system, a just image of the great solar system; ban VIII., who at that time sat on the pontifi- and rendered it more easy to conceive how the cal throne, lessened the rigour of his sentence, moon might attend the earth, as a satellite, in by confining him for a time to the palace and her annual revolution. By discovering hills and garden de Medici at Rome; after which he was cavities in the moon, and spots in the sun consent to the archiepiscopal palace at Sienna, stantly varying, he shewed that there was not where the air was more favourable to his state so great a difference between celestial and subof health; and in the course of the year 1634 lunary bodies as the philosophers had vainly he was permitted to reside at his country-house imagined. He rendered no less service to sciat Arcetri, in the vicinity of Florence. In this ence by treating, in a clear and geometrical place he spent the remainder of his days, visited manner, the doctrine of motion, which has and esteemed by the most distinguished cha- been justly called the Key of Nature. The racters in Florence, and diligently applying rational part of mechanics had been so much himself to his celestial observations. By his neglected, that scarcely any improvement was continual use of the telescope, however, and made in it for almost two thousand years; but the injuries which his eyes received from the Galileo has given us fully the theory of equable nocturnal air, his sight was gradually impaired, motions, and of such as are uniformly accelertill he became entirely blind about three years ated or retarded, and of these two compounded before his death. This calamity he bore with a together. He, first, demonstrated, that the truly philosophical resignation, employing him- spaces described by heavy bodies from the beself in constant meditation and enquiry, the re- ginning of their descent are as the squares of sult of which he intended to communicate to the times; and that a body, projected in any the world. He had digested much matter, and direction that is not perpendicular to the horihad begun to dictate his conceptions, when he zon, describes a parabola. These were the bewas attacked by a distemper which terminated ginnings of the doctrine of the motion of heavy in his death, in 1642, when he was in the sea bodies, which has been since carried to so great venty-eighth year of his age. Galileo was small a height by sir Isaac Newton. In geometry, he in stature, but of a venerable aspect, and of a invented the Cycloid, or Trochoid; though the vigorous constitution. His learning was very properties of it were afterwards chiefly demonextensive; and he possessed in a high degree, a strated by his pupil Torricelli. He invented clearness and acuteness of wit. In company the simple pendulum, and made use of it in bis he was free and affable, and full of pleasantry. astronomical experiments: he had also thoughts He took great delight in architecture and paint- of applying it to clocks; but did not execute ing, and designed extremely well; and he also that design. The glory of that invention was played on the lute with great skill and taste. reserved for his son Vincenzo, who made the Whenever he spent any part of his time in the experiment at Venice in 1649; and Huygens country, he took great pleasure in husbandry. afterwards carried the invention to perfection. From the time of Archimedes, as M. Leibnitz Of Galileo's invention also was the machine

ed by the tegeliby who the fully

other out his disciple were som unde, nico, nobile

with which the Venetians render their Laguna 1623; “ A Letter to Prince Leopold of Tusfluid and navigable. He also discovered the cany, examining the fiftieth Chap:er of Licegravity of the air, and endeavoured to compare tus's Letheosphoros ;” “ A Letter to Christopher it with that of water; and opened up several Greinbergerus, concerning the Montuosity of other enquiries in natural philosophy. He was the Moon,” 1611; “ Mathematical Discourses not esteemed and followed by philosophers only, and Demonstrations concerning two new Scibut was honoured by persons of the greatest dis- ences, relating to Mechanics and local Motions, tinction of all nations. Galileo had scholars together with an Appendix concerning the worthy of so great a master, by whom the gra- Centre of Gravity in some Solids," 1638, &c. vitation of the atmosphere was established fully, The preceding articles, together with some and its varying pressure accurately and conve- other treatises written either by Galileo, or by niently measured, by the column of quick- some of his disciples in defence of his doctrines silver of equal weight sustained by it in the and observations, were collected and publishbarometrical tube. The elasticity of the air, byed by Menolessi, in 1656, under the title of which it perpetually endeavours to expand itself, “ L'Opere de Galileo Galilei Lynceo, nobile and, while it admits of condensation, resists in Fiorentino, &c." in two volumes quarto. Seproportion to its density, was a phenomenon of veral of these pieces were translated into Eng. a new kind (the common fluids having no such lish, and published by Thomas Salisbury, in his property), and of the utmost importance to phi- “ Mathematical Collections,” in two volumes losophy. These principles opened a vast field folio. A volume also of his “ Letters" to seof new and useful knowledge, and explained a veral learned men, and solutions of a variety of great variety of phenomena, which had been ac- problems, was published at Bologna, in quarto. counted for in an absurd manner before that His last disciple, Vincenzo Viviani, who proved time. It seemed as if the air, the fluid in which a very eminent mathematician, methodised a men lived from the beginning, had been then piece of his master's, and published it under the first discovered. Philosophers were every- title of “ Quinto Libro de gli Elementi d'Euwhere busy enquiring into the various properties clide, &c.” 1674, quarto ; and he also puband their effects; and valuable discoveries re- lished some other pieces of Galileo, including warded their industry. Of the great number extracts from his Letters to a learned Frenchwho distinguished themselves on this occasion, man, in which the author gives an account of we cannot but mention Torricelli and Viviani the works which he intended to have published, in Italy, Pascal in France, Otto Guerick in and an extract of a Letter to John Camillo, a Germany, and Boyle in England.” Galileo mathematician of Naples, concerning the angle wrote a number of treatises, of which the prin- of contact. Many other of Galileo's writings cipal, published during his life-time, besides were unfortunately lost to the world, owing to his « Mechanics," “ Balance,” and “ Dia- the superstition of one of his ignorant nephews;. " logues," already mentioned, were, “ The Ope- who, considering that his uncle died a prisoner 'sations of the Compass, geometrical and mili- of the holy office, though permitted to reside 'tary," 1606; “ A Discourse addressed to the in his own house, suspected that his papers most serene, Cosmo II., Grand-duke of Tus- might contain dangerous heresies, and therecany, concerning the Swimming of Bodies upon, fore committed them to the flames. Sir John and their Submersionin, Water," 1612;“Nun- Finch, in a Letter to Thomas Salisbury, attri'cius Sidereus," 1610, of which “ A Continua- butes the destruction of Galileo's MSS. to his sion,” or “ An Essay on the History of Gali- widow's devotion, and the fanaticism of her leo's last Observations on Saturn, Mars, Venus, confessor; but the best authorities maintain that and the Sun, &c.was afterwards collected our philosopher was never married. His son from letters between Galileo and his corre- VINCENZO GALILEI, who, as we have already spondents; “ A Letter concerning the Trepida- seen, honourably supported his father's repuition of the Moon, lately discovered, inscribed tation, by first applying his invention of the to Alphonso Antonini, with Antonini's An- pendulum to clock-work,, was of illegitimate swer,” 1638;“ A Discourse of the solar Spots, birth. &c. with Predictions and Ephemerides of the VINCENZO Galilei, the father of Galileo, Medicean Planets,” 1613; the famous Italian was a man of letters, not unskilled in the mapiece entitled “ Il Saggiatore," written in de- thematics, and particularly conversant in the fence of Guiducci's “ Discourse on Comets,” science of music. He wrote some elaborate and containing a complete account of the physi- works, of which the most esteemed consist of ology and astronomy of our author, printed in five dialogues concerning harmony, and its

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