642 PROFESSOR CHRYSTAL 
SEICHES IN QUARTIC LAKES. 
~§ 52. In a paper recently published in the Society’s Proceedings (vol. xxv. p. 688, 
May 11, 1905) I gave the solution of the seiche problem for lakes whose normal curve 
is a quartic of the form o=A(1=-Fv’/a’). For convenience of reference I recapitulate 
the results here, supposing as usual, for simplicity, that the lake has uniform breadth 
and rectangular cross section, so that the expression for the depth is h x (a’=Fa2’)?. 
ConcavE TRUNCATED Quartic Lake. 
The origin is at O over the deepest point (see fig. 12). The length P Q is /.Band 
x Q 0 le A 
Fie. 12. 
P and Q correspond to x=p,x=g. The depths at P, Q, and O are 7, s, d respectively ; _ 
as rolling 3 se 3n/l-s/9) 
m/e} emer 
The upper signs correspond to the case figured, where P and Q are on opposite sides 
of O. 
