SIDES, THOU SI WIDIBIN ICS gI 
incredible, at first, that any extension of such glaciers could be 
great enough to account for the drift deposits of so great areas 
as those of North America and Europe. Fortunately, our knowl- 
edge of glaciers and of glacial phenomena is not restricted to 
Switzerland, or even to the type of glaciers which has been 
termed alpine. Larger bodies of land ice exist in various parts of 
the world. The largest of these which has received even a small 
amount of attention is the ice cap of Greenland. But this is 
accessible only with difficulty, and has received little attention 
compared to that which has been bestowed on many mountain 
glaciers. While, therefore, the Greenland ice-sheet might afford 
a closer analogy to a continental ice cap than alpine glaciers do, 
it has not been sufficiently studied to give us so reliable a point 
of departure in the discussion of the subject, as the smaller 
glaciers. But it is so large, and departs so far from the alpine 
type of glacier, as to give us an enlarged idea of the dimensions 
which glacier ice may attain, and of the results which it may 
accomplish. Switzerland has an area of about 16,000 square miles. 
It is said to harbor 471 glaciers, 138 of which are more than four 
and three-fourths miles long.‘ According to official surveys, the 
471 glaciers, and the snowfields associated with them, have a 
total area of a little more than 700 square miles. The estimated 
area of the ice cap of Greenland is about 300,000 square miles, 
an area nearly nineteen times as great as that of all Switzerland, 
and about 422 times as great as that of the united area of all the 
Swiss glaciers and snowfields. 
The drift of North America is estimated to cover an area of 
about 4,000,000 square miles,’ an area only a little more than 
thirteen times as large as the area of Greenland’s ice sheet. 
Stated in the form of ratios, therefore, the snow and ice-covered 
area of Switzerland is to the snowand ice-covered area of Greenland 
as I is to 422; while the snow and ice-covered area of Greenland 
isuco) Ene: North yAmencan area or drift as) ltou13. the ratio 
between the entire snow-covered area of Switzerland and the 
Hem, Handbuch der Gletscherkunde, 1885. 
?UpHAM: Appendix to Wright’s “The Ice Age in North America.” 
