186 PEOCEEDiiras or the geological society. [Mar. 5, 



may not be beside the question to state the considerations that led 

 me to reject the old theory. 



Reasons for abandoning the older theories. — I first began to doubt 

 the correctness of my earlier opinions in the summer of 1860, while 

 examining the country near Bonn, the banks of the Moselle, and the 

 Eifel. Neither in the valleys nor on the wide table-lands on both 

 sides of the Ehine and the Moselle is there any sign of glacial drift. 

 Excepting alluvial debris in the valleys, the native rock is generally 

 quite bare of transported detritus ; and the only marks of glaciation lie 

 low on the sides of the Moselle, where the floating down of the river- 

 ice has frequently rounded, polished, and striated the rocky banks in 

 the direction of the flow. Boulders, transported from further up the 

 stream, also sometimes lie on the shores. But, in the absence of true 

 drift, I considered that, had Switzerland been depressed at least 3000 

 feet, until its mountains were washed by a sea that floated trans- 

 ported blocks to the higher Jura, the table-lands of Ehenish Prussia 

 and Westphalia would also possibly have been submerged, and more 

 or less covered with glacial detritus. Further up the Ehine and in 

 the Black Forest the same absence of marine drift prevails. There, 

 looking eastward towards the Ehine, the mountains, chiefly of gneiss, 

 are wonderfully scarred, telling the observer of the wasting effects of 

 frost, ice, rain, and rivers, probably ever since the close of the Miocene 

 period. In the valley of Oberweiler, between MuUheim and the 

 watershed, I observed occasional heaps of moraine-like detritus, in 

 which by diligent searching I found a few stones marked with the 

 familiar glacial scratchings. 



In the interior towards Schonau and the Belchen, the rocks being 

 generally soft and schistose, no very decided signs of old glaciers 

 occur, and no part of the country shows symptoms of the presence 

 of drift. Altogether the country looks as if it had stood in the air 

 for so great a period that, even if glaciers were once present, they 

 had disappeared so long that all the more promiuent signs of degra- 

 dation are now due to rain and running water. But further in the 

 interior it is altogether different; for the signs of old glacier-ice 

 are plentiful enough, and for miles round the Feldberg, which rises 

 4982 Baden feet above the sea, the sides of the valleys to the very 

 summits of the mountains are often strikingly moutonnees, though 

 the rounded forms are generally roughened and frequently half 

 ruined with age. On these, striations, though rare, may occasionally 

 be discovered (running in the direction of the valleys), although 

 the rapid rate at which the rock weathers is much against their 

 preservation. Moraines also are not uncommon. At the foot of 

 the Feldberg, on the east, there is a beautiful circular lake, called 

 the Feldsee, surrounded by taU cliffs of gneiss and granite in the 

 shape known in Scotland as a corrie — a form eminently charac- 

 teristic of all glacier- countries past or present. The outer side of 

 the lake is dammed up by a perfectly symmetrical moraine, curving 

 across the valley, and formed of sand, gravel, and of granite 

 and gneiss, often in large boulders. It is now covered with pine- 

 trees. The lake is deep, and the moraine rises from 25 to 40 feet 



