and the causes of our inferiority are well enough understood. On the contrary, the reasons of our own preëminence in the exact sciences are by no means so generally known. Schiller, who, had he not been a profound philosopher, would never have been the prince of poets that he was, describes the realist as being characterized by a spirit of "sober observation," and the idealist by a spirit of "restless speculation." "When we presume," says he, "by the mere force of reason to determine anything about the outer world, we do but trifle." However obvious the meaning of this remark may at first appear, we shall find, on closer consideration, that in fact the author not only ascribes to the idealistic mind of antiquity an undue bent toward speculation, but that furthermore he plainly denies to it the faculty of correct observation. The entire justice of Schiller's remark, whether as taken in its literal or in its implicative sense, is perhaps nowhere so patent as in the province of astronomy.
Every one knows of the clear skies which canopy the homes of the early civilizations—Italy, Greece, Spain, Egypt, Arabia. The purity of the atmosphere enjoyed by these regions is shown by the importance attached by the ancients to the knowledge of the rising and setting of certain stars. In our countries astronomy must have been precluded from taking the same direction by the fact that but rarely do we see the stars near the horizon, to say nothing of seeing them on the horizon, owing to the presence of haze, which in these regions nearly always narrows the field of view. For this reason, had we not the telescope, we should have been unable to attain to the comparatively accurate knowledge possessed by the ancients with regard to the movements of Mercury, a planet which is hardly visible from our latitudes We inhabitants of Central Europe might easily, in point of cloudy skies, be the rivals of the dwellers on the shores of the Sea of Azof—the Cimmerians of the ancients. It might therefore be supposed that the starry heavens, as these ancestors would describe them to us, must be in great part invisible to us, and far richer than we have been able to see them in later times. We must the more expect them to describe things hardly visible to us as our present division of the northern heavens into constellations dates, as far as its main features are concerned, from at least 2,000 years ago, and the firmament formed an object of studious contemplation even then. Add to this the fact that, as early as the year 130 b. c., Hipparchus began to draw up a complete catalogue of all the fixed stars; and Claudius Ptolemæus, 150 years later, took up this task anew. Now the "Almagest," as Ptolemy's work is called by the Arabs, who handed it down to us, includes 1,028 stars; and even if, on the strength of a remark made by the elder Pliny, who speaks of 1,600 observed stars, we with faint probability grant that the "Almagest" does not represent the complete labors of Hipparchus and Ptolemy, still even the second figure is far less than we should have expected. Argelan-