62 
THE FRESH-WATER LOCHS OF SCOTLAND 
the uppermost one taken near the uninode. All three are somewhat 
embroidered by the wind, but the St Fillans seiche is a UB-dicrote, 
the middle one a nearly pure uninodal, and the uppermost one a 
nearly pure binodal. The figure is at once an interesting confirma- 
tion of ForeFs theory, and a verification of the approximate accuracy 
of the mathematical theory of Loch Earn regarded as a biparabolic 
lake. 
Comparison of Loch Earn wrrn Lochs Tay and Lubnaig 
The seiches of Loch Tay present the strongest possible contrast to 
the seiches of Loch Earn. No clear dicrote or other easily recognisable 
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Fig. 21. 
configuration is ever seen. Often it is not easy even to recognise the 
uninodal seiche. The contrast may be partly realised by looking at 
the two pairs of limnograms in fig. 21. In the first pair is seen 
the beginning of the long seiche on Loch Earn above mentioned. 
