On the Seiches of the Lake of Geneva, 295 



On the Lake of Como also, I had the misfortune of being 

 disappointed. The lake was tempestuous, and, accordingly, I 

 could not make any investigation. It was otherwise at Lugaoo, 

 where 1 Jiad a favourable opportunity of observation in August 

 1804. The weather was hot, and a storm threatened, and I saw 

 four or five times, during the interval of two hours, the waters 

 rise several lines, and at one time in particular, at least five lines. 

 From all this I thought myself authorised to conclude, that the 

 phenomenon of the seiches takes place upon all lakes whatever ; 

 and if it be more remarkable on the Lake of Geneva than on 

 others, that this was owing to the cause which produced it, and 

 which exists every where, though not exercising all its power ex- 

 cept on the surface of the Lake of Geneva. 



Here terminates the recital of the principal observations which 

 were made by Mr Vaucher, during the interval of two years, 

 upon the seiches of the Lake of Geneva, chiefly at its western 

 extremity, and also of those occurring on th^ lakes of Zurich, 

 Annecy, Constance, &c. &c. In a second part of his memoir, the 

 author proceeds to the conclusions which may be deduced from 

 his observations, and to the investigation of the cause of the phe- 

 nomenon. 



He remarks. From all the facts which I have adduced, and 

 from others of which I have said nothing, I think I am entitled 

 to conclude in a general way, 



1*^, That there are seiches more or less considerable upon all 

 lakes ; and regarding those on which they have not hitherto been 

 observed, I should conceive that this was owing to their not 

 having been sufficiently examined. 



2d, That these seiches may take place at all seasons of the 

 year, and indifferently at all hours of the day, but that they are 

 in general most frequent in spring and autumn. 



3d, That nothing appeared to exert a greater influence upon 

 the phenomenon than the state of the atmosphere, so that the 

 steadier the weather the less remarkable the seiches, and the more 

 unsettled the weather the more striking the seiches. All my ob- 

 servations, moreover, proved, that the movement was feeble, if 

 it at all existed, when the wind was from the north, or when the 

 weather was very steadily excellent, or when there was an uni* 



