140 Correspondence — Prof. Edicard Hull. 



necessary to go over his paper in detail. He has advanced 

 nothing new — nothing which has not already been answered 

 by Professor Eamsay and others. One cannot help remarking, how- 

 ever, that it does seem strange that he should quietly ignore the fact 

 that no supporter of the glacial erosion theory has ever asserted that 

 all rock-basins are of glacial origin. Will he kindly tell us what 

 glacialist has expressed disbelief in the existence of special areas of 

 subsidence, or which of us has maintained that volcanic action and 

 the movements accompanying that action cannot possibly have re- 

 sulted in the formation of lake-basins. He states that I appear to 

 assume that faults " can produce no effect at the surface." I neither 

 assume nor assert that such is the case, as any unprejudiced reader 

 of the passage referred to by Mr. Judd cannot fail to see. Professor 

 Ramsay and they who follow him have all along been careful to ad- 

 mit that lakes are \>y no means exclusively of glacial origin. They 

 have not ridden their hobby to death, but this is just what Mr. Judd 

 has done with his along the shores of " Lake Balaton in Hungary." 



Geological Survey, Perth, James Geikib. 



Zlst January, 1876. 



MR. JUDD AND THE GLACIAL EROSION OF LAKES. 



Sir, — I have read Mr. Judd's paper on the origin of Lake Balaton 

 in Hungary^ with interest, and also his concluding observations, in 

 which he proceeds to argue from the special to the general against 

 the views of the " Scotch Geologists " regarding the glacial origin of 

 lakes. I think it will occur to most readers, that however ably Mr. 

 Judd has stated his case, his conclusions are not warranted by his 

 facts ; and that, in bringing the cases of certain large lakes in Ireland, 

 Hungary, the Holy Land, and Central Africa, as evidences against 

 the truth of the views propounded and illustrated by Professor Ram- 

 say, he has not kept within that logical groove of reasoning for which 

 most of his papers are distinguished. 



Without wishing to enter the lists with the author of the paper, I 

 venture to state two or three points on which his conclusions are, as 

 it seems to me, open to objection. In summing up he says :^ " We 

 have demonstrated that the basins of the largest lakes in our own 

 islands, in the Alpine regions of Europe, and in equatorial Africa, could 

 not possibly have been formed by the supposed excavating power of 

 ice. We have also shown that in each of these cases there is the 

 strongest ground for believing the districts in question to have been 

 subjected to powerful subterranean movements ; and that these were 

 quite competent to produce the depressions in question." Well, we 

 may admit that Lough Neagh, Lake Balaton, the great African Lakes, 

 and, I will add, the Dead Sea and Jordan Valley, were not and could 

 not have been formed by glacial erosion. But after this admission, does 

 it by any means follow that Loch Lomond, Lough Doon,^ Winder- 

 mere, the Welsh tarns and lakes, and some of the lakes on both sides 

 of the Alps, were not so formed ? Surely Mr. Judd will not venture 



1 Geol. Mag. No. 139, January, 1876, p. 5. 2 j^^-^;, p, i5_ 



^ See J. Geikie, " The Great Ice ^^q,'' p. 294. 



