Oldal 153 [153]
OCR
CHAPTER IV COLOURS IN RIPPLED WATER b have now arrived at the last division of our subject, in which we have to take into account the colour of the water in combination with a zzó$led surface. We have seen that when—as is usually the case with rippled water (see page 29)—the line of vision strikes the near side of a wave, it is tilted upwards from its normal direction, so that where other objects had before been seen by reflexion in the still water, the eye now receives for the most part reflected skylight. And on page 47 it was pointed out how great a depth of sky affects every part of the rippled water beneath it. Thus it is evident that the apparent colour of the water must be very largely influenced by the general tone of the sky. Though a smooth sea, looked at obliquely, reflects only a low region of the heavens, a rough sea reflects all parts up to a high altitude. And, if in still water on a clear day the lower or paler sky is visible, in rippled water it will be chiefly the deeper light of the upper heaven that meets the eye, with the result that wherever the breeze catches the surface the reflected blue gains in intensity, making the rippled water look darker than the smooth. Should there be black storm-clouds overhead, the water, as soon as it is ruffled by the rising wind, reflects their
