30 
THE FRESH-WATER LOCHS OF SCOTLAND 
presently, these vertical movements of the water are accompanied by 
horizontal movements of even greater range, but these are much more 
difficult to measure, or even to detect. The lake oscillation thus 
roughly described is the simplest variety of what is called a Seiche. 
A seiche in general may be summarily described as a standing or 
stationary oscillation of the whole lake. As will be more fully 
explained presently, the word " standing or " stationary " applies 
to the form of the surface, and indicates that there is no trans- 
lation or progression of the wave-form as in an ordinary train of 
surface waves. 
The word " seiche " has been used, and the phenomenon which it 
denotes known popularly, from time immemorial on the Lake of 
Geneva. The first accurately recorded scientific observation of a 
seiche seems to have been made by Fatio de Duillier, a well-known 
Swiss engineer, in 1730. In the Scots Magazine for 1755 (p. 593 and 
elsewhere) seiches are described, which were caused in several of the 
lakes of Scotland, and in particular in Loch Lomond, by the earth- 
quake of Lisbon on the morning of 1st November 1755. The period 
of this seiche in Loch Lomond seems to have been about ten minutes, 
and its maximum amplitude 2J feet. In his great monograph on the 
Lake of Geneva, vol. ii. p. 50, Forel gives an account of the earlier 
observations of seiches, and refers in particular to one observed at 
Ken more on Loch Tay in 1784, which lasted several hours, having a 
period of seven minutes, and a maximum range of nearly 5 feet. 
The seiches of the earlier observers were in all cases of exceptional 
amplitude, and seem to have been regarded as occasional phenomena 
due to exceptional causes. Even in comparatively recent times there 
appears to have been a belief that seiches were peculiar to the Lake 
of Geneva. It seems to have been J. P. E. Vaucher, Pastor, and 
Professor successively of Botany and Church History at Geneva, who, 
in a memoir written between 1802 and 1804, and published in the 
memoirs of the Physical Society of Geneva in 1833, first pointed out 
that seiches are not confined to Leman, but are to be found more or 
less in all lakes ; that they may have all ranges up to 5 feet or more ; 
and may occur at all seasons of the year, although their occurrence 
seems to be affected by the state of the atmosphere. He also pointed 
out that the range of the seiches in Leman increases towards its 
western end, and that the seiches at its eastern end are not more 
marked than those observed in other lakes. 
But our really accurate knowledge of the phenomena of seiches 
dates from the commencement of ForePs 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 
