Oldal 32 [32]
OCR
I 2 LIGHT AND WATER all of the real house which is above D (D being the corresponding point to d) will appear in the reflexion and no more. But if we ascend to E the image of the house is entirely hidden by the bank B, and our view of the image as a whole is limited by the line B/, so that we only see reflected the small portion of the cliff above the point F. This seems to be the simplest way of regarding reflexions. But some may perhaps find the following preferable. Instead of imagining an inverted image, let the observer suppose himself able to be lowered vertically from the point where he ts standing to a position as far beneath the surfaceas hers actually abovert. The veflexton that appears to him on the water ts identical with the view he would get of the object from this wmaginary point, this view being, of course, inverted. This has already been pointed out with regard to Fig. 3, in which the view of the image from E 1s similar to the direct view of the candlestick from e. So also in Fig. 4 the reflexions seen from C and E are similar to the direct views of the actual landscape from ¢ and e respectively, c and e being imaginary points vertically as far beneath the level of the water as C and E are above it. Again, if Fig. 7 (page 15) is turned upside down, we have the “perverted” view of the house that we should get if it were possible to look at it from a point as far below the surface of the water in a vertical line as that from which the picture is taken. This method is the more convenient for the purposes of a diagram, as it obviates the necessity for drawing the image. For example: suppose a man standing at E (Fig. 5) to see the top of the willow,
