1 92 FRAGMENTS OF SCIENCE. 
many of the ancient moraines, which date from a period 
when almost all the mountains were covered with ice and 
snow, and when, consequently, the quantity of moraine- 
matter derived from the naked crests cannot have been 
considerable. 
The erosion theory ascribes the formation of Alpine 
Valleys to the agencies here briefly referred to. It invokes 
nothing but true causes. Its artificers are still there, 
though, it may be, in diminished strength; and if they are 
granted sufficient time, it is demonstrable that they are 
competent to produce the effects ascribed to them. And 
what does the fracture theory offer in comparison? From 
no possible application of this theory, pure and simple, 
can we obtain the slopes and forms of the mountains. 
Erosion must in the long run be invoked, and its power 
therefore conceded. The fracture theory infers from the 
disturbances of the Alps the existence of fissures: and this 
is a probable inference. But that they were of a magni- 
tude sufficient to produce the conformation of the Alps, 
and that they followed, as the Alpine valleys do, the lines 
of natural drainage of the country, are assumptions which 
do not appear to me to be justified either by reason or by 
observation. 
There is a grandeur in the secular integration of small 
effects implied by the theory of erosion almost superior to 
that involved in the idea of a cataclysm. Think of the 
ages which must have been consumed in the execution 
of this colossal sculpture. The question may, of course, be 
pushed further. Think of the ages which the molten 
earth required for its consolidation. But these vaster 
epochs lack sublimity through our inability to grasp them. 
They bewilder us, but they fail to make a solemn impres- 
sion. The genesis of the mountains comes more within 
the scope of the intellect, and the majesty of the operation 
is enhanced by our partial ability to conceive it. In the 
falling of a rock from a mountain-head, in the shoot of an 
avalanche, in the plunge of a cataract, we often see more 
impressive illustrations of the power of gravity than in the 
motions of the stars. When the intellect has to intervene, 
and calculation is necessary to the building up of the con- 
ception, the expansion of the feelings ceases to be pro- 
portional to the magnitude of the phenomena. 
