Stranica 141 [141]
COLOURS IN STILL WATER — 79
ing that must not be taken too literally. For the re¬
flexion in the foreground of-even a white object, as,
for instance, that of the nearest duck in Plate XX XIV,
may be strongly tinged with the colour of the water,
and, on the other hand, when looking very obliquely,
this colour is quite invisible, even in the reflexions
of very dark objects. But within certain limits of the
angle of vision it is true enough. Though at the
other side of the water we see no green in the reflex¬
ion of the sky, we do see it distinctly in the reflexion
of the dark wall beyond. The image of a black sail
shows much local colour, that of a white sail along¬
side of it hardly any. The effect can also be imitated,
as on page 73, by means of a piece of coloured glass.
At an oblique angle, when the red or blue colour of
the glass cannot be seen in the reflexion of the sky,
it is still visible in the reflexions of dark objects, as
the bars of the window frame. No one who has ever
been rowed into a sea-cave can have failed to notice
as he enters the unusual brilliancy of the colour of
the water within it. In this case practically all light
is cut off from above, so that the rocky bottom, 1I¬
luminated from the opening behind, shows off the
colour of the water to the greatest advantage.’
If we wish to find an object lying at the bottom of
' As a continuation of the experiment on page 75, we may look
(from the second position, Fig. 27), at the reflexions of different
coloured articles, such as books of various colours and shades, and
we shall still find that the darker the object, the more the colour
of the water shows in the reflexion. The image of a dark brown
or dull green book appears much changed by the admixture of the
blue of the water, whilst a light-coloured object is repeated almost
exactly in the reflexion.