THE ORIGIN OF LAKES. 



1"^HE study of lakes has recently attracted so much 

 attention that Limnology is now recognised as a 

 special branch of geography, and a large number of pro- 

 blems connected with lakes are being solved. The one 

 which has been of the greatest interest to geologists is 

 without doubt that of the origin of the hollows in which 

 lakes are contained, and although the existence of a large 

 number of these hollows has been satisfactorily explained, 

 there are many others whose origin is still uncertain. As 

 the subject is one which may well occupy the attention of 

 local observers, no apology is needed for attempting to 

 show the position in which we now stand as regards our 

 knowledoe of the orio-in of lakes. 



General interest in the question of the formation of 

 lake basins was undoubtedly aroused in the first place as 

 the result of the late Sir Andrew Ramsay's paper " On' the 

 Glacial Origin of Certain Lakes in Switzerland," etc., 

 published in 1862(1), in which heablyadvocated theformation 

 of rock basins by glacial erosion, but his views are so well 

 known that it is only necessary to allude to this paper as 

 the starting-point of modern work on lake formation. Since 

 that time a host of observers have paid attention to the 

 physical structure of lake basins, and we now have accurate 

 surveys of a large number of lakes, notably those made by 

 Mill in England and by Delabecque in France. As the 

 result of this work, the subaqueous scenery of lakes is in 

 many cases as well known to us as that above water, and 

 we are consequently able to apply our knowledge of the 

 mode of operation of different agents of erosion with greater 

 certainty than could be done before the execution of these 

 surveys. 



Though the term "rock" is applied by geologists in 

 most cases to aggregates of mineral without reference to the 

 compactness or coherence of the component particles, its 



