600 PROFESSOR CHRYSTAL 
“On the first of November last, Loch Lomond, all of a sudden, and without the 
least gust of wind, rose against its banks with great rapidity, and immediately retiring, 
in about five minutes subsided as low, in appearance, as ever it used to be in the 
greatest drought of summer. In about five minutes after, it returned again, as high 
and with as great rapidity as before. The agitation continued in the same manner, 
from half an hour past nine till fifteen minutes after ten in the morning; the waters 
taking five minutes to subside and as many to rise again. From ten to eleven the 
agitation was not so great; and every rise was somewhat less than the immediately 
preceding one; but taking the same time, viz., five minutes to flow and five to ebb, as 
before. About eleven the agitation ceased. The height the waters rose was measured 
immediately after and was found to be 2 feet 6 inches (76™) perpendicular. The 
same day, at the same hour, Loch Lung and Loch Keatrin were agitated in much the 
same manner; and we are informed from Inverness, that the agitation in Loch Ness 
was so violent as to threaten destruction to some houses built on the sides of it.” 
From this clear description there can be no doubt that the phenomenon observed 
was a longitudinal seiche of Loch Lomond of exceptional amplitude, having a period of 
ten minutes, probably the trinodal or quadrinodal seiche of that lake. The longest 
dimension of both Lomond and Ness is nearly in a straight line with the centre of 
disturbance at Lisbon, and a plurinodal seiche is the result we should expect. The 
greater disturbance in Loch Ness may be due to the fact that one of the seiche periods 
of that lake is about nine minutes. 
But our really accurate knowledge of the phenomena of seiches dates from the 
commencement of ForeL’s own observations at the harbour of Morges, on the Lake 
of Geneva, in 1869. He may with justice be called the Faraday of seiches. He 
worked at first with a small portable apparatus (plemyrameter), and later (1876) 
with a self-registering limnograph installed at Morges, and a portable limnograph 
of simpler construction. In 1877 PLanramour established a magnificent  self- 
registering limnograph at his villa at Sécheron, near Geneva, which has been in 
continuous operation since. In 1879 Sarasin devised his portable limnograph, with 
which observations were made at Tour de Peilz, Chillon, Rolle, and various other 
stations on Léman, and also upon other Swiss lakes. In 1880 the French Govern- 
ment engineers also installed a fixed limnograph at Thonon, with which observations 
have been made under the superintendence of DeLEBecque, Du Boys, and Lauriot. 
During the last twenty years a large number of enthusiastic observers have followed 
the lead given by Foret and his fellow-countrymen; and we have now a great mass 
of information regarding the seiches in lakes in various parts of the world,* from the 
15-hour seiches observed by Henry in Lake Erie, which is 396 km. long, to the 
seiches of 14 seconds, observed by ENpR6s in a small pond whose length was only 
111 m. 
§ 2. The accurate theoretical discussion and co-ordination of the results has scarcely 
* See the extension of Foret’s bibliography appended to this paper. 
