In the whole range of human science, no subject is calculated to excite such sublime ideas as astronomy; and to its study, therefore, the greatest minds have been directed both in ancient and modern times. Ancient, however, as are the investigations into the relations of the heavenly bodies, a correct idea of the planetary system was scarcely known before the sixteenth century of the Christian era. The theory generally received on that subject by the Chaldeans, Egyptians, Greeks, and other ancient nations, and which continued predominant till a comparatively recent period, described the earth as the center of all bodies occupying space, while the Moon, Venus, Mercury, the Sun, the planets, and the stars, revolved around it on a succession of solid spheres, at different distances, and at different rates of speed, so as to produce the appearances which are daily and nightly presented to our eyes in the heavens. Six centuries before the commencement of our era, Anaximander, Pythagoras, and other Grecian philosophers, had conceived some faint notion of a more correct system; but when they ventured to suggest that the sun was a fixed body, and that the earth was only one of a set of planets moving round it, they experienced so much persecution on account of the inconsistency of their doctrines with the religious ideas of the people, that they failed to establish their theory on a permanent basis. When learning and the arts revived in Italy in the fourteenth and fifteenth centuries, some attention was paid in the universities to astronomy; but the system taught was no better than that which Aristotle, Ptolemy, and other ancient astronomers had sanctioned, and which represented the sun and planets as moving round the earth. The time at length arrived for the revival of the correct notions entertained by Anaximander and Pythagoras.
NICOLAS COPERNICUS, the modern to whom the honor of reviving that doctrine is due, was born, February 19, 1473, at Thorn, on the Vistula a place now included in the dominions of the king of Prussia. The father of Copernicus was a native of Westphalia, a part of Germany: he had chanced to settle at Thorn, as a surgeon, about ten years before the birth of his son. Young Copernicus was educated for the profession of medicine at the university of Cracow; but his favorite studies were mathematics, perspective, astronomy, and painting. At an early age, inspired by an eager wish to distinguish himself in astronomy, he proceeded to Italy, and studied that science at the university of Bologna. It is supposed that a discovery of his teacher Dominic Maria, respecting the changes of the axis of the earth, was what first awakened his mind to the errors of the planetary system then taught. From Bologna he proceeded to Rome, where for some time he taught mathematics with great success - pursuing all the while, as far as circumstances would permit, his astronomical observations.
When he afterwards returned to his native country, his maternal uncle, the bishop of Ermeland, appointed him a canon in the cathedral of Frauenburg, and at the same time he was nominated by the inhabitants of his native town to be archdeacon in one of their churches. He then resolved to devote his life to three objects the performance of his clerical duties, gratuitous medical attendance on the poor, and the pursuit of his favorite studies. His residence was established in one of the houses belonging to the canons of Frauenburg, on the brow of a height near the cathedral, where astronomical observations could be conducted under very favorable circumstances and in its walls are still to be seen the openings which he made, in order to observe the passage of stars across the meridian. It is supposed to have been about the year 1507 that he first became convinced of the superiority of the planetary theory of Pythagoras. He determined, however, to be very cautious in adopting, and still more cautious in announcing, an opinion so much at variance with the ordinary ideas of mankind. Mathematical instruments were in that age very rude, and the telescope had not been invented. The only implements which Copernicus had for making observations were two, coarsely framed of firwood, with measures marked by lines of ink. Thus provided, he devoted himself for several years to the inquiries necessary for proving his theory and at length, about the year 1530, he had completed a work, in which the whole system was expounded namely, the immobility of the sun in the centre of the planetary system while its apparent motion, and the alternations of day and night, were to be attributed to the annual and diurnal movements of the earth. The real distances of the planets, and the declination of the pole of the earth, were also explained.