Oldal 62 [62]
OCR
34 LIGHT AND WATER one nearer than D, so that the image would be still more drawn out. We are now able to understand the simple method by which Nature produces this most beautiful effect. As the plainest possible instance, we can imagine the picture FG to represent the white side of a house, the wall below to represent the grassy bank on which it stands, and the wall above the blue sky. The reflexion of the house is drawn out to twice its natural height, the green light from the bank mingles with this for some distance, and the whole is interrupted by patches of blue sky. [he motion of the water gives life to the image, increasing thereby its extreme delicacy both of form and colour. We have supposed the ripples to be parallel to the bank on which we are standing, and, indeed, this is usually the case if the water is not too deep close to its edge, for the waves, whatever their former direction, on reaching shallow water veer round and range themselves parallel to the shore line—so that these interruptions of one part of the image by another take the form of horizontal strokes or lines. This is clearly seen in the foreground of Plate VI; note also the reflexion of the headland in Plate XX XI, page 66. Fig. 14 shows how, looking from Q, a luminous point P may be seen reflected at different points on the surfaces of succeeding waves. A number of lines, representing rays of light, are drawn proceeding from P and hitting the surface of the water, but only those are shown which after reflexion reach the eye at 0. If the water were still, P would be seen by reflexion on the smooth surface at the point X, its image
