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 Hildons 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 Hildons, 
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- 
