142 
Proceedings of Boyal Society of Edinburgh. [sess. 
Some Experimental Results in connection with the 
Hydrodynamical Theory of Seiches. By Peter 
White, M.A., and William Watson. 
(MS. received March 15, 1906.) 
In a paper read before the Royal Society of Edinburgh, in June 
1905, on the Hydrodynamical Theory of Seiches, Professor 
Chrystal published a number of formulae from which could be 
calculated the periods and positions of the nodes of seiches in 
lakes of various shapes. 
The solutions of the most general problems, involving variations 
of the three dimensions, are there made to rest ultimately upon 
certain typical cases in which the element of breadth remains 
constant while the depth is some defined function of the length. 
In the paper referred to, formulae are given immediately applic- 
able to lakes of uniform breadth, whose longitudinal sections 
include concave and convex parabolae, quartic curves, and recti- 
linear shapes. 
The present paper owes its origin to a suggestion by Professor 
Chrystal, to find out how closely the values given by these 
formulae coincided with the results of actual experiments made 
with models to represent the typical cases. 
The experiments were carried out with water in a rectangular 
trough whose dimensions were — length, 15 ‘2 cm. ; breadth, 10 "5 
cm.; depth, 12*5 cm. The curves characterising the special 
forms of the body of water to be experimented with were 
calculated and transferred to blocks of wood, which were cut and 
fitted into the trough, being weighted with lead to keep them in 
position. 
The experiments involved the determination of two classes of 
results — the periods of the different seiches excited and the 
positions of the nodes of these seiches. The nature of the problem 
will best be illustrated by reference to the particular case in which 
the water is in the form of a concave-parabolic curve. 
