74 THE MOUNTAINS OF COLORADO. 
is approached. Here the soil reposes on a water-washed gra 
but the beds of the streams are composed of shifting sands. 
vancing towards the foothills, small boulders are observed stroi 
over the surface, and occasionally it is traversed by ridges of 
In fact the observer experiences a feeling of disappo 
ment at the absence of the more striking drift phenomena; 
naturally comparing this region with the Alps, he expects tos 
great outlying masses of rock which have been transported 
from the parent bed ; accumulations of gravel and sand in the1 
ture of terminal moraines; and rock surfaces which have been 
planed down and striated. Entering the mountains, the cliffs 
are jagged, no where exhibiting those smooth outlines seen in t 
Alps and called by De Saussure, roches moutonnées. The ench 
ing banks of the streams are made up of large egg-shaped 
bles and occasional boulders two and three feet in diameter. 
of these materials, so far as I have observed, are striated, 
Taking Clear Creek as the line of my observation, these W 
worn materials do not attain ah elevation above its bed of 
than one hundred feet, and tracing the smaller streams to Nigh” 
elevations they soon disappear and are replaced by nee fan 
ments. 
The transporting power of the present streams is very 8 
They have a descent of from fifty to one hundred feet to the 
and, swollen by the spring freshets, the waters sweep — 
sufficient force to bear along the largest boulders here obs 
particularly if entangled in ice. 
other phenomenon characteristic of all true drift. regions, 
entirely wanting on the plains, and but sparingly represented 
the mountains ; and that is the absence of lakes. Professor 
sey, as far back as 1862, in a paper communicated to the ‘ 
ical Society of London, pointed out the fact that lakes were 
numerous in those regions where the evidences of ice action 
most manifest, and comparatively rare in tropical and su00"™ 
cal regions; and maintained that they were actually due to. 
erosion of their basins by glaciers. 7 
The scenery of the Alps derives one of its principal et er 
from the abundance of its lakes. We may refer to. Geneva 
stance and Zurich, near the borders of the mountains, ie 
Lakes of the Four Cantons, Lago Maggiore, and Como, 2 
