Oldal 139 [139]
OCR
COLOURS IN STILL WATER . 77 of colour. But if the sun is high and shining brightly on the water, the whole pond (except in the shadows) shows its greenish colour, and that chiefly in the dark tree-reflexions. The reflexion of the tree-stem on the farther side of the pond seems, when the sun is hidden, to be identical in colour with the real stem, but as soon as the sunlight strikes the water again, its gray is mingled with green. Wherever a shadow falls across the surface, the colour of the water is less prominent, and therefore the reflexion-picture there is more prominent. So that in drawing shadows on still water, we must make the reflexions seen in the shadows clearer and purer in colour than those seen outsidethem. It follows that if the water is very clear and practically colourless, there will be hardly any noticeable difference between shadow and sunshine. Indeed we may safely say that no difference would be visible were it not for minute particles of dust—or even seeds or leaves—that may be floating on the surface. On the other hand, when the water is very turbid, the shadows falling upon it are quite obvious. Plate X XX VI isa photograph of a very muddy pond in bright sunlight. The outline of the shadow of the . tree in the foreground is clearly defined. Within this shadow the image of the trees on the opposite bank appears nearly as plainly as it would in clear water; but beyond the shadow, that is to say, wherever direct sunlight falls on the pond, the muddy colour of the water is so strongly brought out that the reflexions, or at any rate the darker parts of them, are scarcely distinguishable. In the English Channel,
