350 Mr. Bowman on Terraces formed by Glaciers. 



the causes now explained would produce, and are at this day 

 producing in Switzerland. Their occurrence also on the spur 

 of Williamlaw, which projects into the valley of the Gala, and 

 on the Eildons facing the great valley of the Tweed, which I 

 attempted to show was incompatible with the laws of tidal 

 action, are thus satisfactorily explained ; and I feel persuaded 

 that the theory of their formation by water must be aban- 

 doned, and that they must be considered to be the true mo- 

 rains of ancient glaciers. 



But all the terraces on the hills round Galashiels cannot 

 be exclusively attributed to the cause already assigned. Some 

 of them, it will be recollected, are stated by Mr. Kemp to be 

 as much as 300 feet wide. On requesting from Prof. Agassiz 

 an explanation of these broad terraces, he stated that, as far 

 as he could judge from my description, they probably were 

 not true morains, but had been formed by the combined ac- 

 tion of a glacier and a lake dammed up by ice, such as once 

 formed the barrier of Glen Roy, and in our own day blocked 

 up the stream at the foot of the glacier of Getroz, which 

 finally burst and devastated the valley. I confess that the 

 height at which these broad terraces occur on the Eildons, 

 appears to me incompatible with such a view, and that if 

 Agassiz himself were to visit the locality, he would find it 

 necessary to modify this explanation. I also pointed out to 

 him Mr. Kemp^s description of the indentations on the in- 

 clined projecting slopes of Williamlaw ; and he replied that 

 he had seen something similar in the cliffs in Glen Roy, 

 which he attributed to the friction of floating ice and blocks 

 of stone. 



In conclusion, Prof. Agassiz informed me that in his late 

 travels he had traced repeated instances of the various descrip- 

 tions of morains in different parts of Scotland ; in Murray- 

 shire he counted a series of nine terraces similar to those in 

 Selkirkshire.* He had also seen them in Ireland, and between 

 Shap and Kendal, in Westmoreland; and he does not doubt 

 they will be recognized, now that attention is directed to the 

 subject, in North Wales, in the Pyrenees, the Apennines, and 

 other high mountain chains. Indeed he believes, from strong 

 evidences scattered over different countries, that at a recent 

 geological period, and not long before the creation of the 

 human race, the whole of Europe, and those parts of Asia and 

 America which lie north of the parallel of the Mediterranean 

 and Caspian seas, were enveloped in snow and ice ; in short, 

 consisted of a series of immense glaciers, above which only 

 the highest hills appeared as islands ; presenting a character 

 of scenery only to be found in our day in Greenland or Ice- 



