38 THE ICE AGE IN NORTH AMERICA. 



About half a mile from the sea, on the highest part of the 

 ridge, perhaps two hundred and fifty feet above high-water 

 mark, at a depth of a foot, we came to a solidly frozen stratum 

 consisting chiefly of bog-moss and vegetable mold, but con- 

 taining good-sized lumps of clear ice. There seemed no reason 

 to doubt that an extension of the digging would have brought 

 us to solid clear ice such as was visible at the face of the bluff 

 below ; that is to say, it appeared that the ridge itself, two 

 miles wide and two hundred and fifty feet high, was chiefly 

 composed of solid ice overlaid with clay and vegetable mold. • 



The ice in general had a semi-stratified appearance, as if it 

 still retained the horizontal plane in which it originally con- 

 gealed. The surface was always soiled by dirty water from the 

 earth above. This dirt was, however, merely superficial. The 

 outer inch or two of the ice seemed granular, like compacted 

 hail, and was sometimes whitish. The inside was solid and 

 transparent or slightly yellow-tinged, like peat -water, but 

 never greenish or bluish like glacier-ice. But in many places 

 the ice presented the aspect of immense cakes or fragments 

 irregularly disposed, over which it appeared as if the clay, etc., 

 had been deposited. Small pinnacles of ice ran up into the 

 clay in some places, and, above, holes were seen in the face of 

 the clay bank, where it looked as if a detached fragment of ice 

 had been melted out, leaving its mold in the clay quite perfect.* 



After speaking of the frequency with which the bones of 

 the mammoth and buffalo and other animals are found, and 

 of portions of the earth which still has in it the odor of the 

 decaying flesh, Dr. Dall adds : 



Dwarf birches, alders seven or eight feet high, with stems 

 three inches in diameter and a luxuriant growth of herbage, 

 including numerous very toothsome berries, grew with the 

 roots less than a foot from perpetual solid ice. 



The formation of the surrounding country shows no high 

 land or rocky hills, from which a glacier might have been 

 derived and then covered with debris from their sides. The 

 continuity of the mossy surface showed that the ice must be 



* "American Journal of Science," vol. cxxi, 1881, pp. 106-109. 



