Oldal 160 [160]
94 LIGHI AND WATER
bay, as often happens on the west coast of Scotland,
the contrast is still more striking. From a little dis¬
tance 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 look¬
ing 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 advanc¬
ing 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, par¬
ticularly if the sun is in an opposite quarter and shin¬
ing 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¬