'^ Nakamura and K. HonaaT 



jöünScTcoll., Vol. XXVIII., Art. 5, PI. XIII. 



Fix. 1. 



Kawaguchi lake, ti=1.36 sec. 



Fiff. 2. 



Kawaguchi lake, t2=0.62 sec. 



Fig. 3, 



KawagucH lake, t3=0.46 sec. 



