Stranica 98 [98]
OCR
54 LIGHT AND WATER Plate XXXV, page 74). In Plate XXIV, at that part of the surface where the inside of the ring appears, sky is seen by a double reflexion. We have already had an instance of this in Fig. 13 (page 32). When looking towards 4, the line of vision cannot continue in the direction 4g, but, striking the near side of the next wave, is again reflected, so that sky is seen in the direction gf. Fig. 18 shows the extent of the reflexion of the bank PS on the farther side of the first "NEEE EAK eg a RA BE ága ga AR E áá ug NE NE EK ENENMNE EA NEG EE NEEE NEEE EGEN E NEEE EK AR ER tt ae Fa ee ee ee ee (tes ERGA tintin 2 22 "u wo oe ee KGN eee eee eee ee ev an án EGER hea ec ec 2 Ő 8 E ‘Stet ttiatans te eee ee Ge nee ee KENE KK NO KA OH m E “Set eee ee ee ~« ene eee eee a ee ee MA NN os tT ee ee EEG Ste NOW a BM 2 gy HHF HE EGEN ENNE ANEEEEEEEEAA Tu oO eee eee EN EKE NE AE Se ee e RK KÓ Hl fal lel NE I el ia ja 98 E be da d adá b ee KE a Gő 8 B. see et tig te Perec eae es Reece ee cee = oe" sd a 2 Re ég B 8 B a d d 8 Mi in mi 7 égő 8 SRR PRR eee eee 8 B m i. SSR RRR STREP ee ee EE sec coe eT PCR eae eee Se Se UL LU SRP RR RRR RPP ee eS EE WE GE ENE EN KE A! —— eee ee” gh mses re g Fig. 18. The point P is seen reflected at two points on the surface of the first wave, viz., ő and /. Nearer than JZ, as, for instance, at a, we see sky, as indicated by the dotted line. Beyond 4 we see bank (PV) reflected as far as c, where the top of the second wave comes in the way, hiding all the bank below V. Beyond c, asat d, the line of vision, being further depressed, strikes the side of the next wave at 4, and is therefrom reflected up towards the sky. dh represents about the lowest inclination of the line of vision after reflexion, and beyond d it begins to rise again, until at e the bank (at T) is again visible over the top of the next wave. From e we continue to see bank as far as f£, where P 1s again reflected; and beyond 7, as at g, again only sky. In order to give greater clearness to the diagram, the space between the lines Q4P and QcV is tinted, and also that between QeT and Q/P. wave when looking from Q. The reflexion of the bank appears only on the two short portions (4c and ef) of the surface which are darkened in the figure, and between these sky is seen by a further reflexion on the
