That study of our Earth in its entirety falls properly within the province of astronomy, is not only deducible from its relationship to the other planets, but demonstrable from the cosmic causes that have been at work upon it, and the inadequacy of anything but cosmic laws to explain them. The ablest geologists to-day are becoming aware of this,—we have one of them at the head of the geology department of the Institute,—while from the curious astronomy at second hand which gets printed in geologic text-books, by eminent men at that, dating from some time before the flood,—of modern ideas,—it seems high time that the connection should be made clear. For, after all, our Earth too is a heavenly body, in spite of man’s doing his best to make it the reverse. It has some right to astronomic regard, even if it is our own mother. At the same time it is quite puerile to consider the universe as bounded by our terrestrial backyard. If man took himself a thought less importantly, he might perceive the humor of so circumscribed a view. Like children we play at being alone in the universe, and then go them one better by believing it too. I shall, of course, not touch on any matters purely geologic, for fear of committing the very excesses I deplore; mentioning only such points as astronomy has information on, and which, by the sidelights it throws, may help to illuminate the subject. Thus it certainly is interesting and may to many be a new point of view, that the changes introduced when paleologic times passed into neologic ones were in their fundamental aspects essentially astronomic; which shows how truly astronomic causes are woven into the whole fabric of the Earth. For it was then only, terrestrially speaking, that the year began. The orbital period had existed, of course, from the time the Earth first made the circuit of the Sun. But the year was more a _succès d’estime_ on the Sun’s part than one of popular appreciation. As the Sun could not be seen and worked no striking effects upon the Earth, the annual round had no recognizable parts, and one revolution lapsed into the next without demarcation. Only with the clearing of the sky did the seasons come in: to register time by stamping its record on the trees. Before that, summer and winter, spring and autumn, were unknown.