Page:Popular Science Monthly Volume 23.djvu/335

Rh conveys high praise. For it is just because it is true that these mighty children became the fathers of natural knowledge. Men of science are eternal children, always asking questions of Mother Nature, and never content with her answers.

But, whether questions are childlike or childish, depends upon the knowledge and the intelligence of the questioner; and Herodotus, as I have said, was largely endowed with both. Let me remind you that he lived midway between Thales and Aristotle, in the very heart and center of the great age of Greece; and let me also remind you of the fact, of which people too often remain ignorant throughout their school and university career, that, if this was an epoch of great achievements in art, in literature, and in philosophy, it was no less distinguished for the sedulous cultivation of physical science. Democritus, the contemporary of Herodotus, was the great exponent of principles which have played, and still play, a great part in modern scientific speculation. Half a century before Herodotus, Xenophanes had observed petrified marine shells and fish-bones in the quarries of Syracuse and elsewhere; he had drawn the conclusion that the rocks in which they were contained were the hardened mud of the bottom of the sea in which the corresponding animals once lived; and he had laid down the general proposition that the geographical features of our earth are not constant, but that where land now is, sea has been, and where sea is, land has been. And it is a corollary from this proposition that the land which constitutes any country has not always been what it is and where it is, but that it has a history, unwritten save in the hieroglyphics of Nature. Herodotus is not likely to have been ignorant of the speculations of Xenophanes, but it is in evidence that his extensive travels had enabled him to observe facts which led directly to like conclusions. The plain of Ilium and the estuary of the Mæander had shown him rivers at work in the formation of new land, and he adverts to the conclusions to be drawn from the presence of shells in the rocks which bound the Nile Valley.

To a mind thus prepared by an acquaintance with elementary truths of physical science, the first glance at Egypt can not fail to suggest inquiry, and, in fact, Herodotus says as much:

"Any one who sees Egypt, without having heard a word about it before, must perceive, if he has the least intelligence, that the Egypt to which the Greeks go in their ships is a gift of the Nile to the Egyptians." That is to say, as he elsewhere explains, the rich soil of the great plain, or so-called Delta of Egypt, has been formed out of the deposits left by the Nile during the annual inundation. The region occupied by the delta, he adds, was "evidently, at one time, a gulf of the sea. It resembles, to compare small things with great, the parts about Ilium and Teuthrania, Ephesus, and the plain of the Mæander. In all these regions the land has been formed by rivers, whereof the