Stranica 53 [53]
OCR
REFLEXIONS IN RIPPLED WATER 29 is looking from E at the surface of the near wave at A. In order to find the direction of his line of vision after reflexion, we may suppose there to be a tiny mirror floating on the surface of the water at A; this mirror will be tipped up towards him, and his line of vision will be along AB (the angle of reflexion being equal to the angle of incidence, as explained in the last chapter), whereas, if the water had been smooth, he would have been looking on the level surface at C, and his line of vision would have taken the direc¥ Dic... Fig. 12. Lines of vision, on striking the near sides of the waves, deflected towards the sky. tion CD. (The dotted lines represent the condition in smooth water.) Ihere are of course points on the surface even when the water is disturbed, as, for instance, on the crest of a wave at F, where a floating mirror would assume a horizontal position, but it is evident from the figure that in the great majority of cases the line of vision strikes a surface inclined fowards the observer, and is therefore reflected up towards the sky, in some cases less, in others more. The result is that it is only at certain comparatively minute spots that we catch sight of the image that would appear in smooth water, these spots being surrounded by surfaces reflecting the sky
