Page:Encyclopædia Britannica, Ninth Edition, v. 10.djvu/42

Rh 32 honour must be assigned to Ilans Lippershey, an obscure optician of Middleburg, who, on the 21st of Uctober 1608, offered to the states of Holland three instruments by which the apparent size of remote objects was increased. 3ut here his glory ends, and that of Galileo begins. The rumour of the new invention, which reached Venice in April or May 1609, was suﬁicient to set the Italian philo- sopher on the track; and after one night's profound mezlitation on the principles of refraction, he succeeded in producing a telescope of threefold magnifying power. Fpon this first attempt he rapidly improved, until he attained to a power of thirty-two, and his instruments. of which he manufactured hundreds with his own hands, were soon in request in every part of Europe. Two lenses only—a plane- convex anda plane-concave—were needed for the composition of each, and this simple principle is that still employed in the construction of opera-glasses. Galileo’s direction of his new instrument to the heavens formed an era in the history of astronomy. Discoveries followed upon it with astound- ing rapidity and in bewildering variety. The Sz'dr=reus IVuncz'us, published at Venice iii the early part of 1610, contained the ﬁrst-fruits of the new mode of investigation, which were snﬂicient to startle and surprise the learned on both sides of the Alps. The mountainous conﬁguration of the moon's surface was there ﬁrst described, and the so- called “phosphorescence” of the dark portion of our satellite attributed to its true cause-—nan1ely, illumination by sun—light reflected fron1 the earth.‘ All the time-worn tables and conjectures regarding the composition of the Milky Way were at once dissipated by the simple statement that to the eye, reinforced by the telescope, it appeared as a congeries of lesser stars, while the great nebulae were equally declared to be resolvable into similar elements. But the discovery which was at once perceived to be most important in itself, and most revolutionary in its effects, was that of J upiter’s satellites, ﬁrst seen by Galileo January 7, 1610, and by him named Siclera illedicea, in honour of the grand-.luke of Tuscany, Cos1no II., who had been his pupil, and was about to become his employer. An illustration is, with the general run of mankind, 1nore powerful to convince than an argument ; and the cogency of the visible plea for the Copernican theory offered by the miniature system, then for the first time disclosed to view, was recognizable in the triumph of its advocates, as well as in the increased acrimony of its opponents. In September 1610 Galileo ﬁnally abandoned Padna for Florence. Ilis researches with the telescope had been re- warded by the Venetian senate with the appointment for life to his professorship, at an unprecedentedly high salary. His discovery of the “ Medicean Stars ” was acknowledged by his nomination (July 12, 1610) as philosopher and mathematician extraordinary to the grand—dul<e of Tuscany. The emoluments of this ofﬁce, which involved no duties save that of continuing his scientiﬁc labours, were fixed at 1000 scudi; and it was the desire of increased leisure, rather than the promptings of local patriotism, which induced him to accept an oﬁfer, the ﬁrst suggestion of which had indeed come from himself. Before the close of 1610_ the memorable cycle of discoveries begun in the previous year was completed by the observation of the ansated or, as it appeared to Galileo, triple form of Saturn (the ring-formation was ﬁrst recognized by Huygens in 1655), of the phases of Venus, and of the spots upon the sun. Although his priority in several of these discoveries has been contested, inquiry has in each case proved favourable to his claims. In the spring of 1611 he visited Rome, and exhibited in the gardens of the 1 Leonardo da Vinci, more than a hundred years earlier, lmif come to the same conclusion. G A L 1 L 1*] 0 Quirinal Palace the telescopic wonders of the heavens to the most eminent personages at the pontiﬁcal court. En- couraged by the flattering reception accorded to him, he ventured, in his Letters on tile Solar Spots, printed at Rome in 1013, to take up a more decided position towards that doctrine on the establishment of which, as he avowed in a letter to Belisario Vinta, secretary to the grand-duke, “all his life and being henceforward depended.” liven in the time of Copernicus some well-meaning persons had sus- pected a discrepancy between the new view of the solar system and certain passages of Scripture a suspicion strengthened by the anti-Christian inferences drawn from it by Giordano Bruno ; but the question was never formally debated until Galileo’s brilliant discoveries, enhanced by his formidable dialectic and enthusiastic zeal, irresistibly challenged for it the attention of the authorities. Although he earnestly deprecated the raising of the theological issue, and desired nothing better than permission to pursue un- molested his physical demonstrations, it must be admitted that, the discussion once set on foot, he threw himself into it with characteristic impetuosity, and thus helped to pre- cipitate a decision which it was his ardent wish to avert. In December 1613 a Benedictine monk named Benedetto Castelli, at that time professor of mathematics at the uni- versity of Pisa, wrote to inform Galileo of a recent discus- sion at the grand—ducal table, in which he had been called upon to defend the Copernican doctrine against theological ob'ections. This task Castelli, who was a steady friend and dislciple of the Tuscan astronomer, seems to have discharged with moderation and success. Galileo’s answer, written, as_l1e said himself, c-mwnte calamo, was an exposition of a formal theory as to the relations of physical science to Holy Writ, still further developed in an elaborate apology ad- dressed by him in the following year (1614) to Christina of Lorraine, dowager grand—duchess of Tuscany. Not satisﬁed with explaining adverse texts, he met his oppon- ents with unwise audacity on their own ground, and endea- voured to produce scriptural conﬁrmation of a system which to the ignorant many seemed an incredible paradox, and to the scientiﬁc few was a beautiful but daring innovation. The rising agitation on the subject which, originating pro- babl with the sincere upholders of the integrity of Scrip- ture,y was foniented for their own purposes by the rabid Aristotelians of the schools, was heightened rather than allayed by these manifestoes, and on the fourth Sunday of the following Advent found a voice in the pulpit of Santa Maria Novella. Padre Caccini’s denunciation of the new astronomy was indeed disavowcd and strongly condemned b v his su )CI‘lOI‘S; nevertheless, on the 5th of February 1i3l5, anolher Dominican monk named Lorini laid Galilco’s letter to Castelli before the Inquisition. Cardinal Robert Bellannine was at that time by far the most inﬂuential member of the Sacred College. He was a man of vast learning and upright. piety, but, although per- sonally friendly to Galileo, there is no doubt that he saw in his scientiﬁc teachings a danger to religion. The year 1615 seems, however, to have been a period of suspense. Galileo received, as the result of a conference between Cardinals Bell-armine and Del Monte, a semi—oflici-.11 warning to avoid theology, and limit himself to physical reasoning. “ VVrite freely,” he was It“-olpl by 1lO]11Slgll1OI‘1 l)(11n1,1 “ bpt keep outside the sacrist '. 'n ortunate ', 1e Ia a neat y com- mitted himself toidangerousgroundii In December he re- paired personally to Rome, full of conﬁdence lthat the weigllii of his arrruments and the vivacity of his e oquence cou L not fail tbo convert the entire pontiﬁcal court to his views. He was cordially received, and eagerly listened to, but his imprudent ardour served but to injure his ca11se. On the 24tl1,'of February 1616 the consulting theologians of the Holy Office characterized the two propositions—that the sun