that of Aristarchus, because of his attempt to determine the distance of the sun from the earth. Though his method was ingenious in theory, it proved false in practice. For he concludes that the sun is eighteen times the moon's distance from the earth; we know that it is four hundred times that distance. Indeed, the greatest astronomers of antiquity could not determine the distances, nor the magnitudes, of any of the bodies of our system; but such have been the improvements in the methods of the science, that the mathematician can now calculate them with exactness and ease.

Among all the astronomers of antiquity, Hipparchus stands pre-eminent. Endowed with one of those vast intellects which, by its compactness, its vigor, its comprehensiveness, its acuteness, its originality, and its depth, was destined to make an impression on all succeeding ages, he has ever been the admiration of astronomers, to whose favorite pursuit his immortal powers were almost exclusively devoted. Even Delambre, though usually so severe in his judgments, relaxes into praise as he approaches the name of Hipparchus; pronouncing him 'one of the most extraordinary men of antiquity, the very greatest in the sciences which require a combination of observation and geometry.' And M. Auguste Comte, by grouping Hipparchus and Kepler and Newton together, as the three great lights of astronomy, has, if possible, still more impressively expressed the estimation in which he held the father of astronomy.' You will naturally ask, then, what constitutes his title to so proud a distinction, to so high a niche in the temple of fame, to so imperishable a chaplet of glory as that which encircles his lofty brow?

We answer, the theories of the sun and moon, as propounded by him, were far more perfect than those of his predecessors. In the second place, he reformed the calendar and introduced greater accuracy into the computations of time. Thirdly, he founded the science of trigonometry, a branch of the mathematics without which the very alphabet of physical astronomy could not have been constructed; for it is by the application of trigonometry, that the distances and the magnitudes of the various bodies of our system are determined. Thus, the real facts

of astronomy, which are so amazingly different from the apparent ones, are due to the method first invented by Hipparchus. Fourthly, his grand discovery of the precession of the equinoxes, which was made one hundred and twenty-eight years before Christ, was indispensable to the future progress of astronomy. Fifthly, the astronomical observations which were made by him alone, and transmitted to posterity, exceeded in number and value all the observations he had received from all his predecessors. And, lastly, his sixth great labor, which in that early age, Pliny regarded as pertaining to the Deity rather than to man, consisted in a construction of a catalogue of the fixed stars. By this labor alone, he created an era of light in the history of the science; and if the labor was immense, its results have been of incalculable benefit to all succeeding astronomers.

But, if we mistake not, he deserves as much credit for what he did not attempt, as for what he actually accomplished. Having proceeded as far as the light of nature seemed to guide him, he there resolutely halted, and refused to advance or bury himself among the obscurities of nature. The art of talking unintelligibly on matters of which we are ignorant', is one of the fine accomplishments which he does not seem to have learned from Aristotle, or from any of his predecessors. In one word, his object seems to have been, not so much the illustration of his own name, as the discovery and propagation of truth. Hence, the miserable weakness of pretending to know all things, and to explain all things, formed no part of the intellectual character of Hipparchus. In this respect, he presents a glorious contrast to many of the most renowned philosophers of Greece; and, as the bright and morning star of astronomical science, he will ever be, even as he now is, most reverently admired. The astronomical dreams of a Plato and an Aristotle have passed away; the discoveries of Hipparchus will live forever.

From the time of Hipparchus, who flourished one hundred and twenty years before Christ, down to that of Ptolemy, a period of about two centuries and a half, no real astronomer appeared. The works of Hipparchus have been lost; not so with those of Ptolemy. It is to these works, says Mr. Whewell, that we owe ninety-nine-hundredths of all our knowledge of the Greek astronomy.

Ptolemy possessed, not only a great, but also a versatile mind; yet it is as an astronomer, that he has ever been held in the highest estimation among men; for it was to this noble science, then languishing in the schools, that he gave a new and lofty impulse. He brought together and united the scattered materials existing in the works of Hipparchus and others; which, combined with his own discoveries, formed a complete system of astronomy as the science was then understood. The publication of his Μαθηματίκη συνταξία forms a great epoch in the history of the science. This work, which fortunately escaped the barbarism of the middle ages, formed the basis of all the astronomy of the Arabians, and, for a considerable time, that of modern Europe. If our design would permit, we should be glad to give an outline of the contents of this great work; but we must hasten on to the more important and more interesting eras of the science.

But in passing down from Ptolemy, how shall we speak of the dark ages? We see the angelical doctors' there; but we see them engaged in no very angelical pursuits. The same 'wilderness of suns', which looked down on Pythagoras, is shining on them too; but yet it seems that the great angelicals refuse to dabble in such gross material things as stars or stones. Instead of studying the great world which God has built, they are constructing little worlds of their own, here upon this atom earth of ours, out of the entities and quidities, and privations and forms, of Aristotle. The categories and predicables are their sun and moon; and the topics are their stars. To these they look for light; in these they search for the glory of God. How the heavenly bodies move, or by what laws they are governed, is a question which they put aside for the sublime speculations, 'whether a disembodied spirit can go from one place to another without passing over the intermediate points?' They seek to know, not how many myriads of shining orbs adorn the halls of space, but how many myriads of spirits may dance, all at once, upon a cambric needle's point! And why, indeed, should they care to know how many mansions there are in this our Father's house of the universe; since for aught they know, created spirits might creep at once into a single needle's eye, and there conceal themselves!

all

Yet one friendly glance, at least, is due from us to these great 'angelicals'; for they are near of kin to us. Then hail to you, ye logicizing, metaphysicizing, mighty dreamers of the misty past; we greet you with a kindly feeling from the heart! For had we been born and lived with you, we too, perchance, had been a brother of your craft, and dwelt amid the cobwebs of the brain. But as it is, thank God, born in a better age, we may despise ourselves in you; and quit both you and self to dwell with greater minds, whose glorious thoughts have raised us from these little souls of ours.

During the dark ages, the science of astronomy took its flight from the Christian world. If any one, like Gerbert, for example, happened to feel a passion for the study, he had to seek an instructor either among the Arabs, or in the Moorish universities of Spain. He could find no teacher in Christian countries. For more than a thousand years, the science of astronomy suffered this dark eclipse. But then a more propitious era began to dawn, and continued to brighten with a steadily progressive lustre; until about the middle of the sixteenth century, it burst on the Christian world in full-orbed splendor, never more to decline, or to become obscured. Nicholas Copernik, an ecclesiastic and recluse philosopher, was the author of this wonderful revolution. No man ever lived, indeed, who was more worthy to follow philosophy than he; for he was a freeman in mind.' His was not the freedom of those, however, who think much of themselves, and know but little'; for he knew how to reverence the mighty past, as well as to think for the everlasting future. His freedom was inspired, not by the intoxicating fumes of a vain-glorious disposition, but by a profound love of truth, and consisted in the greatness and the glory of his discoveries.

of man.

An intellect like his could not but strive, and strive with energy, after that unity and harmony of principle, that symmetry and beauty of view, which alone can fully satisfy the rational nature Hence the complexity and confusion which reigned in the Ptolemaic system of the world, proved offensive to his mind. As this was the system then universally received, and no better was dreamed of, so had Copernicus thought more highly of himself, he might have boasted with Alphonso X., 'Had the Deity

consulted me at the creation of the universe, I could have given him some good advice.' Good advice he could have given, far better indeed than King Alphonso, provided the real model of the universe had been such as it was then distorted and misrepresented in the schools. But shunning the error of the proud Castilian monarch, Copernicus more wisely concluded, that the manifold imperfections which had shocked his reason and clouded his imagination, existed not in the divine scheme of the universe itself, but only in the human interpretations of that scheme. Dissatisfied with the labors of the past, and weary of the uncertainty of the mathematical traditions', he resolved to try anew, and for himself, the stupendous problem of the world. He felt the necessity of the task, as well as the glory of the attempt.

'Then, I, too, began to meditate', says he, and for forty long years he continued to meditate. With Pythagoras, and Philolaus, and Anaximander, and Aristarchus, he placed the sun in the centre of the world; and gave to the earth a motion around that great luminary, as well as around its own axis. Over this sublime scheme, his mind continually brooded. He rose above the illusion of the senses; and saw more clearly than mortal eye had ever seen before, that the motion of the heavens is apparent only, while that of the earth is real. Having taken a firm hold of this theory, by means of his clear geometrical conceptions, he made it explain the phenomena of the heavens, far better than they had, until then, been explained; and, by immense mathematical calculations, he verified his explanations. Thus did he find, in some good measure at least, that order and harmony, that simplicity and beauty, for which his rational nature had so passionately longed.

As we have already seen, it was not the merit of Copernicus, that he was the first to conceive the true system of the universe. But if he was not the author, he was certainly the founder, of that system. The arguments and views which had imposed on the mighty intellects of Plato, and Aristotle, and Hipparchus, and Ptolemy, and which had led the whole world astray, disappeared before the blaze of his intense mind, like mists before the sun. Beneath his thinking also, those vague considerations which had controlled the opinions of Pythagoras and his fol