OCR
94 LIGHI AND WATER bay, as often happens on the west coast of Scotland, the contrast is still more striking. From a little distance the turbid water looks the colour of sand, whilst the margin of smooth wet sand along the shore takes that of the sky. It is thus clear that, taking the waves zzdzvidually, their nearer sides show more local colour and their farther sides more reflected colour. And when there is no breeze to roughen the surface, more local colour and less sky reflexion may usually be detected looking across the wave crests than looking along them. But in a general effect the local colour becomes most conspicuous when a stiff breeze is blowing, so that the whole surface of the water is ruffled, especially if one is looking into the wind, for then the line of vision strikes abruptly the steep sides of the advancing waves and their farther sides are out of sight. Thus the local colour is very prominent, whilst the reflected colour is reduced toa minimum. The colour of the Alpine lakes already referred to appears for the same reason most brilliant on a windy day, particularly if the sun is in an opposite quarter and shining directly onto the farther sides of the waves, the edges of which then show glimpses of their own pure emerald. The bright green colour of the glacier-fed lakes, seen under these conditions, mingled with the deep blue reflected from the sky, forms a combination scarcely equalled in brilliancy by anything in nature. But the local colour is often entirely masked by the brightness of the reflexion on the rippled surface. For instance, as we stand by the shore of one of these mountain lakes, with its natural colour of un