to one in which the earth is but a planet like Mars, moving in appearance among the stars, as it does, and rotating with a rapidity that brings a whole hemisphere of the heavens into view through the course of a single day and night. At first sight, what a loss of dignity! but, on closer thought, what a gain of grandeur! No longer some little neighbouring lights shine down upon us from a solid vault; but we find ourselves launched into the sea of infinity; with power to gaze into its almost immeasurable depths.

To appreciate rightly our position, we have to plant ourselves, in imagination, in some spot removed from the surface of the earth, where we may be uninfluenced by her motion, and picture to ourselves what we should see. Were we placed in some spot far enough removed from the earth, we should find ourselves in eternal day; the sun would ever shine, for no great globe would interpose itself between it and our eyes; there would be no night there. Were we in the neighbourhood of the earth's orbit, and within it, most wonderful phenomena would present themselves. At one time the earth would appear but an ordinary planet, smaller than Venus, but, as time wore on, unmeasured by recurring days or changing seasons, it would gradually be seen to increase in size—now appearing like the moon at the full, and shining like her with a silver light. As it came nearer, and its magnitude increased, the features of the surface would be distinguished; the brighter sea and the darker shining continents, with the brilliant ice-caps at the poles; but, unlike what we see in the moon, these features would appear to move, and, one after another, every part of the earth would be visible. The actual time required for all to pass before us would be what we here call a day and night. And still, as it rotates, the earth passes nearer to us, assumes its largest apparent size, and so gradually decreasing again, becomes once more, after the interval we here call a year, an ordinary-looking star-like planet. To us, in these days, this description is easy of imagination; we find no difficulty in picturing it to ourselves; but, if we will think for a moment what such an idea would have been to the earliest observers of astronomy, we shall better appreciate the vast change that has taken place—how we are removed from them, as we may say, toto cœlo.

But not only as to the importance of the earth in the universe, but on other matters connected with astronomy, we perceive the immensity of the change in our ideas—in that of distance, for instance. This celestial vault of the ancients was near enough for things to pass from it to us; it was in close connection with the earth, supported by it, and therefore of less diameter; but now, when our distance from the sun is expressed by numbers that we may write, indeed, but must totally fail to adequately appreciate, and the distance from the next nearest star is such, that with the velocity of light—a velocity we are accustomed to regard as instantaneous—we should only reach it after a three years' journey, we are reminded of the pathetic lines of Thomas Hood:

The astronomer's answer to the last line would be that as far as the material heaven goes, we are just as much in it as the stars or as any other member of the universe; we cannot, therefore, be far off or near to it.

It is probable that we are even yet but little awake to true cosmical ideas in other respects;—as to velocity, for instance. We know indeed, of light and electricity and the motions of the earth, but revelations are now being made to us of motions of material substances in the sun with such velocities that in comparison with them any motions on the earth appear infinitesimally small. Our progress to our present notions, and appreciations of the truth of nature in the heavens, will thus occupy much of our thoughts; but we must also recount the history of the acquirement of those facts which have ultimately become the basis for our changes of idea.

Our rustic forefathers, whatever their nation, were not so enamoured of the "wonders of science"—that their astronomy was greatly a collection of theories, though theories, and wild ones, they had; it was a more practical matter, and was believed too by them to be more practical than we now find reason to believe to be the case. They noticed the various seasons, and they marked the changes in the appearances of the heavens that accompanied them; they connected the two together, and conceived the latter to be the cause of the former, and so, with other apparently uncertain events. The celestial phenomena thus acquired a fictitious importance which rendered their study of primary necessity, but gave no occasion for a theory.

That we may better appreciate the earliest observations on astronomy, it may be well to mention briefly what are the varying phenomena which may most easily be noticed. If we except the phases of the moon, which almost without observation would force their recognition on people who had no other than lunar light by night, and which must therefore, from the earliest periods of human history have divided time into lunar months; there are three different sets of phenomena which depend on the arrangement of our planetary system, and which were early observed.

The first of these depends upon the earth's rotation on its axis, the result of which is that the stars appear to revolve with a uniform motion from east to west; the velocity increasing with the distance from the pole star, which remains nearly fixed. This circumstance is almost as easy of observation as the phases of the moon, and was used from the earliest ages to mark the passage of time during the night. The next arises from the motion of the earth in her orbit about the sun, by which it happens that the earth is in a different position with respect to the sun every night, and, therefore, a different set of stars are seen in his neighbourhood; these are setting with him, and therefore also a different set are just rising at sunset every evening. These changes, which would go through the cycle in a year, are, of course, less obvious, but of great importance as marking the approach of the various seasons during ages in which the hour of the sun's rising could not be noted by a clock. The last depends on the proper motions of the moon and planets about the earth and sun respectively, by reason of which those heavenly bodies occupy varying positions among the stars. Only a careful and continuous scrutiny of the heavens would detect these changes, except, perhaps, in the case of the moon, and but little of importance really depends on them; nevertheless, they were very early the subject of observation, as imagination lent them a false value, and in some cases because their connection with eclipses was perceived. The practical cultivation of astronomy amongst the earliest people had always reference to one or other of these three sets of appearances, and the various terms and signs that were invented were intended for the clearer exposition of the results of their observations on these points.

In looking therefore into extreme antiquity we shall find in many instances our only guide to what their knowledge was is the way in which they expressed these results.

We do not find, and perhaps we should scarcely expect to find, any one man or even one nation who laid the foundation of astronomy—for it was an equal necessity for all, and was probably antecedent to the