Englacial Drift. — Upham. 41 
glacial currents to move gradually upward from the ground 
to the ice surface. Such a supposition, however, seems to me 
quite untenable. Instead, in my own writings and those of 
most if not all of these authors, the exposure of the drift on 
the surface of the ice-sheet near its border, whence much of 
it was washed away t<> form the eskers, kames, and valley 
drift, is ascribed wholly to the superficial melting of the ice- 
sheet, which is called ablation. Twenty years ago Prof. N. 
H. Winchell, with almost prophetic vision, as if seeing the 
drift-covered and forest-clad borders of the Malaspina glacier 
or ice-slieet, between 3It. St. Elias and the ocean, which was 
explored by Russell* in 1891 and 1892, wrote as follows of 
the Xorth American ice-sheet : 
In regions far to the north, the eye probably would not be able to 
discern any object except that of the universal ice. The surface of the 
ground would be thousands of feet below the traveller, if we may be 
permitted to presume so hardy a human being. Like Dr. Kane ex- 
ploring the great Humboldt Glacier of Greenland, he would meet with 
countless obstacles and dangers. But those obstacles would consist of 
hummocky ice, or crevassed ice, or perpendicular ice-walls. He would 
see no soil, no rocks, no vegetation, no animal life. The winds would 
whistle, storms would rage, snow would be drifted about, and the in- 
effectual sun would rarely venture to smile on the dreary waste. 
Farther to the south, the explorer would find isolated spots of bare 
ground. He would see about them the accumulated debris of bowlders, 
gravel and dust, from constant winds, spread more or less over the 
ice-field, staining its painful whiteness, and showing the more grateful 
aspect of earth and stones. Another hundred miles farther south, and 
he finds the evidence of the dissolution of the ice-sheet multiplying. 
Occasional streams of water run on the surface of the ice, or plunge 
into some of its openings. Dee]) gorges reveal multitudes of fragments 
of rock frozen into the ice, and occasional bands of dirt and gravel 
embraced in the solid ice. The surface is everywhere dirty, or perhaps 
muddy, from the wasting away of the surface of the glacier. He meets 
frequent openings, in which generally water may be seen or heard. 
Into these gorges the debris slides down the sloping sides, increasing 
the insecurity of hi6 footsteps. Still farther south, the general surface 
is covered with a pulpy earth, mingled with stones and bowlders. The 
ice is evidently much attenuated. The areas of firm, uncovered terra 
firma are wonderfully increased in size and frequency. The ice itself 
is crowded into the valleys, or, if it be in a broad, level tract, like the 
State of Minnesota, the surface is covered with the dCbris of the con- 
*National Geographic Magazine, vol. iii, 1891, pp. 53-20:5, with 19 
plates and maps. Am. Jour. Sci., Ill, vol. xliii. pp. 109-182, with map, 
March, 1892. A.m. Geologist, vol. viii, p. 384, Dec, 1891. 
