Page:The Gradual Acceptance of the Copernican Theory of the Universe.djvu/35

 not merely nine years but for "more than three nines of years." It had not been neglected all this time, however, as the original MS. (now in the Prague Library) with its innumerable changes and corrections shows how continually he worked over it, altering and correcting the tables and verifying his statements.

Copernicus was a philosopher. He thought out a new explanation of the world machine with relatively little practical work of his own, though we know he controlled his results by the accumulated observations of the ages. His instruments were inadequate, inaccurate and out of date even in his time, for much better ones were then being made at Nürnberg ; and the cloudy climate of Ermeland as well as his own active career prevented him from the long-continued, painstaking observing, which men like Tycho Brahe were to carry on later. Despite such handicaps, because of his dissatisfaction with the complexities and intricacies of the Ptolemaic system and because of his conviction that the laws of nature were simple and harmonious. Copernicus searched the writings of the classic philosophers, as he himself tells us, to see what other explanation of the universe had been suggested. "And I found first in Cicero that a certain Nicetas had thought the earth moved. Later in Plutarch I found certain others had been of the same opinion." He quoted the Greek referring to Philolaus the Pythagorean, Heraclides of Pontus, and Ecphantes the Pythagorean. As a result he began to consider the mobility of the earth and found that such an explanation

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