very recently, with the holes which he made in the walls of his room in order to observe the passage of the stars across the meridian.
His position here was not, however, one of uninterrupted peace. It fell to him more than once to administer the affairs of the bishopric during a vacancy, and he was charged with the duty of defending the rights and privileges of the see against the Teutonic Knights, who were then very strong. These positions, says M. Biot in the Biographie Universelle, demanded probity and courage. "Copernicus let himself neither be dazzled by the authority of the Knights nor intimidated by their threats. If we repeat these details, which appear foreign to his glory, it is to show that in his character the taste for study and contemplation were united with firmness and constancy—qualities not less necessary than genius for attacking and overthrowing prejudices that had been consecrated by the faith of centuries."
Copernicus lived at the time of the awakening of knowledge, and was a part of it. The idea that the earth moved around the sun was not new; it had been uttered before, but, like many other thoughts that had been expressed among the ancients and then slumbered through the middle ages, it, being contrary to the received notions, was frowned on by authority and was refused a hearing. Copernicus saw, what an intelligent observer could not fail to see, that none of the systems then known could account for the motions of the stars. He had met the most distinguished astronomers of his own time. He was acquainted with all the systems of the ancients; and the more he examined them the more he was astonished at the want of harmony and inconsistency that marked them. "I then took pains," he says, "to read again all the books of philosophy that I could get, to assure myself whether I could find any different opinions from those which were taught in the schools concerning the motions of the spheres of the world. And I saw first in Cicero that Nicetas had expressed the opinion that the earth moves. Then I found in Plutarch that others had had the same idea... . Further, the leading Pythagoreans, Archytas of Tarentum, Heraclides of Pontus, Echrecrates, etc., taught the same doctrine, according to which the earth is not motionless in the center of the world, but turns in a circle, and is far from holding the first rank among the heavenly bodies." Pythagoras had learned the same doctrine; Timæus of Locris was very precise in announcing it, when he called the five planets the "organs of time on account of their revolutions," and added that we should have to suppose that the earth was not immovable in the same place, but that it turned around itself and was also carried along in space. Plutarch says that Plato, who had always taught that the sun turned around the earth, changed his opinion
