Caroline. The streak of sunshine, then, which we now see upon the water, is composed of those rays which by their reflection, happen to fall upon my eyes?
Mrs. B. Precisely.
Emily. But is that side of the house yonder, which appears to be in shadow, really illuminated by the sun, and its rays reflected another way?
Mrs. B. No; that is a different case, from the sheet of water. That side of the house, is really in shadow; it is the west side, which the sun cannot shine upon, till the afternoon.
Emily. Those objects, then, which are illumined by reflected rays, and those which receive direct rays from the sun, but which do not reflect those rays towards us, appear equally in shadow?
Mrs. B. Certainly; for we see them both illumined by reflected rays. That part of the sheet of water, over which the trees cast a shadow, by what light do you see it?
Emily. Since it is not by the sun's direct rays, it must be by those reflected on it from other objects, and which it again reflects to us.
Caroline. But if we see all terrestrial objects by reflected light, (as we do the moon,) why do they appear so bright and luminous? I should have supposed that reflected rays, would have been dull and faint, like those of the moon.
Mrs. B. The moon reflects the sun's light, with as much vividness as any terrestrial object. If you look at it on a clear night, it will appear as bright as a sheet of water, the walls of a house, or any object seen by daylight, and on which the sun shines. The rays of the moon are doubtless feeble, when compared with those of the sun; but that would not be a fair comparison, for the former are incident, the latter, reflected rays.
Caroline. True; and when we see terrestrial objects by moonlight, the light has been twice reflected, and is consequently, proportionally fainter.