A still more disgraceful case, except that it did not terminate fatally, was that of the renowned astrologer Galileo. It belongs to a later date and occurred in the pontificate of Urban VIII, the pope who first armed the castle of St. Angelo with artillery. Urban VIII was also a champion persecutor, an energetic patron of the Holy Office, of whose merciless activity he thoroughly approved. Widespread alarm prevailed in Italy when it was seen that the Inquisition not only dealt summarily with religious opinions but also, yielding to the most prejudiced ignorance, was fiercely opposed to the advancement of natural science. Galileo, who had reached his seventieth year at the time of his troubles, had long resided in Florence, his native city, as a professor of mathematics under the protection of Ferdinand. He was far in advance of his age and had made many important discoveries. He had gauged the exact oscillations of the pendulum and had invented an astronomical clock; he brought out the first microscope, and with a long range telescope he established many remarkable astronomical facts, such as the explanation of the Milky Way as a collection of small stars, and that the moon was a burned out planet whose light was due to reflection. He dared, moreover, to adopt the theory of Copernicus, that the earth revolved round the sun and not the sun round the earth. When he published his own observations in support of this novel and startling theory, he fell at once under the censure of the Inquisition. The extravagant views entertained by Galileo were pronounced to be absurd, false and heretical. The cardinal-inquisitors referred the writings of Galileo to their literary advisers who, of course, passed a strongly condemnatory verdict upon them. Galileo was warned to abandon the incriminating doctrine and carefully to abstain from teaching it. The astronomer promised to do this, but did not keep his word and ventured to write a dialogue between three persons; one of them still in doubt, the second a believer in the Ptolemaic system--that held by the priests--and the third a disciple of Copernicus and Galileo. When this dialogue was circulated, Pope Urban VIII fancied that he had been caricatured in one of the characters and became greatly enraged against Galileo, who was again summoned before the Holy Office. The grand-duke, Ferdinand, was reluctant to surrender him but his priest-ridden grand-duchess implored him to yield obedience to the Church; and poor Galileo, now in failing health and a prey to great fear, was sent back to Rome to be again arraigned before the tribunal. We have an account of his adventures in his own hand.