Page:The Gradual Acceptance of the Copernican Theory of the Universe.djvu/98

 a third edition was issued only two years later together with the second book; "Discourse concerning a New Planet—that 'tis probable our Earth is one of the planets." In this latter, the Bishop stated certain propositions as indubitable; among these were, that the scriptural passages intimating diurnal motion of the sun or of the heavens are fairly capable of another interpretation; that there is no sufficient reason to prove the earth incapable of those motions which Copernicus ascribes to it; that it is more probable the earth does move than the heavens, and that this hypothesis is exactly agreeable to common appearances. And these books appeared when political and constitutional matters, and not astronomical ones, were the burning questions of the day in England. The spread of the doctrine was also helped by Thomas Salusbury's translations of the books and passages condemned by the Index in 1616 and 1619. This collection, "intended for gentlemen," he published by popular subscription immediately after the Restoration, a fact that indicates that not merely mathematicians (whom Whewell claims were by that time all decided Copernicans) but the general public were interested and awake.

The appearance of Newton's Principia in 1687 with his statement of the universal application of the law of gravitation, soon ended hesitancy for most people. Twelve years later, John Keill, (1671-1721), the Scotch mathematician and astronomer at Oxford, refuted Descartes's theory of vortices and opened the first course of lectures delivered at Oxford on the new Newtonian philosophy. Not only were his lectures thronged, but

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