Stranica 98 [98]
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 re¬
flexion 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 be¬
tween these sky is seen by a further reflexion on the