The major planets are the only ones at the present moment in this self-centred and self-sustained stage. Their great size has kept them young. In the smaller terrestrial planets we could not expect to witness any such condition to-day. If they experienced an ebullient youth, they have long since outgrown it. Only by rummaging their past could we find evidence on the point, and this, distance both in time and space bars us from doing. There is but one body into whose foretime career we could hope to peer with the slightest prospect of success—our own Earth. [Illustration: THE VOLCANO COLIMA, MEXICO, MARCH 24, 1903—JOSÉ MARIA ARREOLA, PER FREDERICK STARR.] [Illustration: JUKES BUTTE, A DENUDED LACCOLITH, AS SEEN FROM THE NORTHWEST—GILBERT.] [Illustration: IDEAL SECTION OF A LACCOLITH—GILBERT.] Whether our Earth was ever hot enough at the surface to vaporize those substances which now form the Jovian or Saturnian clouds, we do not know; but that it was once hot enough to vaporize water we are perfectly certain. And this from proof both of what did exist and of what did not. That the surface temperature was at onetime in the thousands of degrees Fahrenheit, the Plutonic magma underlying all the sedimentary rocks of the Earth amply shows. Reversely, the absence of any effect of water until we reach these sedimentary deposits, testifies that during all the earlier stages of the Earth’s career water as such was absent, and as water subsequently appeared, it is clear that the conditions did not at first allow it to form. We are sure, therefore, that there was a time when water existed only as steam, and very possibly a period still anterior to that when it did not exist at all, its constituent hydrogen and oxygen not having yet combined. There was certainly an era, then, in the morning of the ages, when the Earth wore her cloud-wrapper much as Jupiter his now. That the seas were not once and yet are to-day, affords proof positive that at some intermediate period they began to be. Avery long intermediate one it must have been, too,—all the time it took the Earth to cool from about 2000° C. to 100° C. Not till after the temperature had fallen to the latter figure in the outer regions of the atmosphere could clouds form, and not till it had done so at the solid surface could the steam be deposited as water. Reasoning thus presents us with a picture of our Earth as a vast seething caldron from which steam condensing into cloud was precipitated upon a heated layer of rock, to rise in clouds of steam again. The solid surface had by this time formed, thickening slowly and more or less irregularly, and into its larger dimples the water settled as it grew, deepening them into the great ocean basins of to-day. We see the process with as much certainty and considerably more comfort than if, in the French sense, we had assisted at it. Presence of mind now thus amply makes up for absence of body then.