caution, when he hesitated to publish the work which had cost him the labor of so many years.
Rheticus, one of the friends to whom he had communicated his theory, at length, in 1540, ventured to give an outline of it to the world in a small pamphlet, which he published without his name. As this excited no disapprobation, the same person reprinted it next year with his name. In both publications the doctrines were ascribed openly to Nicolas Copernicus. About the same time, a learned man, Erasmus Reinhold, in a work which he published, spoke of the new doctrines with the greatest respect, and styled their author a second Ptolemy; for it often happens that the greatest compliment that can be paid to the discoverer of truth, is to mention him in the same breath with some founder of error. Copernicus now allowed himself to be pursuaded by his friends to publish his work; and it was accordingly put to press at Nuremburg, under the care of some learned persons of that city. But he was now an old man, and it was not his lot to live to see the book published. As soon as it was printed, a copy of it was sent to him by his friend Rheticus, but it only reached him, May 23, 1543, a few hours before he expired. He appeared to be scarcely conscious of the object to which so many years of his life had been devoted. But his mission was accomplished. Committed to the perpetuating operations of the infant printing-press, all danger was over of losing the germ of those great and fertile truths which in our days render astronomy the most perfect of sciences.
The theory of Copernicus was thus brought before the world; but, whether from the death of the philosopher, or because little disturbance of popular notions was anticipated from so learned a work, or from whatever other circumstances, it was visited with no marks of reprobation from any quarter at the time. In proportion, however, as it became known, so did its opponents increase. Those were the days when the fagot and stake made short work with those who presumed to strike out a course of thinking for themselves; and though the author of the system and its immediate adopters passed unmolested, yet during the century which ensued were its followers and supporters persecuted with all the zeal and cruelty that bigotry and ignorant prejudice could devise. Truth, however, is imperishable; and, though repressed and retarded for a season, is ever sure to take its right place among the established beliefs of mankind. And thus it has been with the Copernican theory, whose importance to the progress of accurate science we cannot in reality over-estimate. To form anything like an adequate idea of the value of its author's services to the cause of science, we must place ourselves back in the time and circumstances which saw their birth. Then, it must be remembered, the want of telescopes rendered all appearances in the sky much more difficult of explanation than they would have been a century later. The accumulated errors and superstitions of fourteen centuries were not to be easily shaken and removed; neither were the prejudices and dogmas of the learned to be disturbed with impunity. What might have been astronomical science, was, even in the writings of the fathers, little better than a mass of absurd and subtle disquisitions on the substance of the heavens and the heavenly bodies. All these Copernicus had to surmount; and the elaboration of his theory presents an ever-memorable example of the power of patient and earnest thought in the
