116 FIELD CoLuMBIAN MustuM—GEoLocy, VOL. I. 
the foot of the present glacier, converging in their course toward the 
mouth of the valley, lie two great ridges of debris, which from their 
form and the character of the material of which they are composed, 
appear to be old lateral moraines. Their position is indicated in 
Pl.XV. Pl. XVII is a nearer view of the northern moraine taken from 
the point marked cin Pl. XV. The point of view is the crest of the 
smaller ridge of the two into which the northern moraine is divided and 
the view looks westward along the ridge course. While the southern 
moraine was not submitted to close inspection, it appeared from a 
distance to be a counterpart of its northern companion. Of the 
northern moraine (for, as has been said, there are properly two ridges 
of drift lying side by side), the largest or one farthest from the 
glacier, is about one-third of a mile in length and maintains a height 
of about 60 feet above the slope of the mountain, The inner one 
is shorter and less than one half the height of the other, but in other 
respects similar to it. It is separated from it by a sharply-defined 
trough such as to show that the ridges are distinct in origin. The 
sides of these ridges slope at a uniform angle of from 30° to 40°, 
being as steep as the angle of rest will, for the debris of which they 
are composed, permit. ‘This is made evident when one attempts to 
climb the slope of the moraine, for every step brings down a shower 
of stones and sand. The upper surface of the ridge is nearly level 
and its edge sharp. The size of the bowlders poised on the crest of 
the ridge or upon one another, and their delicate adjustment of 
position all over the moraine indicate that they were left in place by 
the melting of the ice beneath them. No assortment of the debris, 
such as might be expected from the rolling of the coarser bowlders to 
the bottom has yet taken place, nor is any stratification apparent. 
All the material hes in an unassorted condition. It seems proper, 
therefore, to regard these moraines as of comparatively recent origin. 
A large proportion of the bowlders examined on both moraines were 
distinctly rounded, scored and smoothed, and gave positive evidence 
of having been subjected to glacial action. This fact, together with 
the shape and extent of the ridges, stamps these positively as 
moraines of glacial origin and precludes the supposition of their being 
talus cones. 
I believe the manner of their formation is similar to that now in 
progress at the base of the northern cliff as shown in Pl. XV. Here 
the debris brought down on the side of the glacier is spread out along - 
the base of the cliff. Being thus protected, the ice underneath this 
earthy covering does not melt so rapidly as on the exposed surface 
of the glacier itself. At the contact of the two a trough is formed by 

