Here Apollonides, taking up the discourse, said: Tell me then, I beseech you, good sir, even by the moon herself, do you think it possible that there should be there shadows of caves and chinks, and that the sight of them should come even to our eyes? Or do you not regard what will come of it? And must I tell you what it is? But hearken to me, although you are not ignorant of it. The diameter of the moon, according to that bigness which appears to us when she is in her mean and ordinary distances, is twelve digits, and every one of these black and shady spots is above half a digit, that is above the four and twentieth part of the diameter. Now if we suppose the circumference of the moon to be only thirty thousand stadia; and the diameter according to that supposition to be ten thousand, every one of these shadowy marks within her will not be less than five hundred stadia. Consider then, first, whether there can possibly be in the moon such great gaps and such inequalities as may make such a shadow? And then how is it possible that, being so great, they are not seen by us? At this I, smiling upon him, said: You have done me a pleasure, dear Apollonides, in having found out such a demonstration by which you will prove that you and I shall be bigger than those giant sons of Aloeus,—not indeed every hour of the day, but principally morning and evening,—if indeed you think that, when the sun makes our shadows so long, he suggests to our minds this goodly argument; if that which is shadowed is great, that which shadows must of necessity be yet excessively greater. I know well that neither you nor I have ever been in Lemnos; yet we have often heard that Iambic verse, so frequent in every one’s mouth: Mount Athos’ shade shall hide the Lemnian cow. For the shadow of that mountain falls, as it seems, on the image of a brazen heifer which is in Lemnos, extending itself in length over the sea not less than seven hundred stadia. The mountain which makes the shadow causes it, because the distance of the light renders the shadow of bodies manifoldly greater than the bodies themselves. Consider then here, that when the moon is in the full, and shows us the form of a visage most expressly, by reason of the profundity of the shadow, it is then that she is most remote from the sun; for it is the distance of the light that makes the shadow bigger, and not the greatness of the inequalities which are on the superficies of the moon. And you moreover see, that the brightness of the sun’s beams suffers not the tops of the mountains to be discerned in open day; but on the contrary, the deep hollow and shadowy parts appear from afar. It is not therefore any way absurd or strange, if we cannot so exactly see how the illumination of the moon and her reception of the sunbeams take place, while yet the conjunction of things that are obscure and dark to such as are clear and shining is by reason of this diversity apparent to our sight.