Page:Mathematical collections and translations, in two tomes - Salusbury (1661).djvu/98

 do ask the question seriously; and therefore answer me: and if afterwards you shall think that I speak impertinently, I will be content to be the senseless man: for he is much more a fool who interrogates simply, than he to whom the question is put.

If then you do not think me altogether simple, take it for granted that I have answered you already, and said, that it is impossible, that one that is upon the Earth, as we are, should see by night that part of the Earth where it is day, namely, that is illuminated by the Sun.

Therefore you have never seen the Earth enlightned, save onely by day; but you see the Moon to shine also in the dead of night. And this is the cause, Simplicius, which makes you believe that the Earth doth not shine like the Moon; but if you could see the Earth illuminated, whilst you were in some dark place, like our night, you would see it shine brighter than the Moon. Now if you desire that the comparison may proceed well, you must compare the light of the Earth, with that of the Moon seen in the day time, and not with the same by night: for it is not in our power to see the Earth illuminated, save onely in the day. Is it not so?

So it ought to be.

And forasmuch as you your self have already confessed to have seen the Moon by day among some little white Clouds, and very nearly, as to its aspect, resembling one of them; you did thereby grant, that those Clouds, which yet are Elementary matters, are as apt to receive illumination, as the Moon, yea more, if you will but call to mind that you have sometimes seen some Clouds of vast greatness, and as perfect white as the Snow; and there is no question, but that if such a Cloud could be continued so luminous in the deep of night, it would illuminate the places near about it, more than an hundred Moons. If therefore we were assured that the Earth is illuminated by the Sun, like one of those Clouds, it would be undubitable, but that it would be no less shining than the Moon. But of this there is no question to be made, in regard we see those very Clouds in the absence of the Sun, to remain by night, as obscure as the Earth: and that which is more, there is not any one of us, but hath seen many times some such Clouds low, and far off, and questioned whether they were Clouds or Mountains: an evident sign that the Mountains are no less luminous than those Clouds.

But what needs more discourse? See yonder the Moon is risen, and more than half of it illuminated; see there that wall, on which the Sun shineth; retire a little this way, so that you see the Moon sideways with the wall: look now; which of them shews more lucid? Do not you see, that if there is any advantage,