Anaxagoras may never have seen an eclipse of the moon, and even if he had he might have reflected that, from certain directions, a disk may throw precisely the same shadow as a sphere. Moreover, in reference to the shadow cast by the earth, there was, so Anaxagoras believed, an observation open to him nightly which, we may well suppose, was not without influence in suggesting to his mind the probable shape of the earth. The Milky Way, which doubtless had puzzled astronomers from the beginnings of history and which was to continue to puzzle them for many centuries after the day of Anaxagoras, was explained by the Clazomenaean philosopher on a theory obviously suggested by the theory of the moon's phases. Since the earth-like moon shines by reflected light at night, and since the stars seem obviously brighter on dark nights, Anaxagoras was but following up a perfectly logical induction when he propounded the theory that the stars in the Milky Way seem more numerous and brighter than those of any other part of the heavens, merely because the Milky Way marks the shadow of the earth. Of course the inference was wrong, so far as the shadow of the earth is concerned; yet it contained a part truth, the force of which was never fully recognized until the time of Galileo. This consists in the assertion that the brightness of the Milky Way is merely due to the glow of many stars. The shadow-theory of Anaxagoras would naturally cease to have validity so soon as the sphericity of the earth was proved, and with it, seemingly, fell for the time the companion theory that the Milky Way is made up of a multitude of stars. It has been said by a modern critic(1) that the shadow-theory was childish in that it failed to note that the Milky Way does not follow the course of the ecliptic. But this criticism only holds good so long as we reflect on the true character of the earth as a symmetrical body poised in space. It is quite possible to conceive a body occupying the position of the earth with reference to the sun which would cast a shadow having such a tenuous form as the Milky Way presents. Such a body obviously would not be a globe, but a long-drawn-out, attenuated figure. There is, to be sure, no direct evidence preserved to show that Anaxagoras conceived the world to present such a figure as this, but what we know of that philosopher's close-reasoning, logical mind gives some warrant to the assumption--gratuitous though in a sense it be--that the author of the theory of the moon's phases had not failed to ask himself what must be the form of that terrestrial body which could cast the tenuous shadow of the Milky Way. Moreover, we must recall that the habitable earth, as known to the Greeks of that day, was a relatively narrow band of territory, stretching far to the east and to the west. Anaxagoras as Meteorologist