634 REVIEWS 



the same tract (Fig. 2). On it the glaciers appear as the offspring of 

 the snow fields of the mountains that crown the divide and they flow 

 rationally from their local gathering grounds in various directions in 

 due respect to gravitation and the usual habit of glaciers. The glacier 

 near Ikamiut is represented as descending from the snowfield of a 

 neighboring mountain and as finding its source some two-score miles 

 away from the edge of the inland ice which the author nowhere more 

 nearly approached. 



Aside from scenic and geographic features, there are two observa- 

 tions of the author that bear on general glaciology : "These glaciers 

 on the south side are all of them thicker near the base of the mountain 

 than in their higher levels. Indeed, they seem to run down like cold 

 tar and to thicken at the base as a stiff semi-fluid would under the 

 action of gravity" (p. 95). "Another phenomenon illustrating the 

 nature of the movement going on in great glaciers was seen here to 

 special advantage. Where the great ice-sheet abutted against the 

 mountain which divided its front into two portions it was pushed up 

 by the momentum of the movement so as to be two or three hundred 

 feet higher at the base of the mountain than it was a mile back. 

 Indeed, a half mile or so back there was a distinct depression in the 

 glacier with the ice higher all around it. It was just such a depression 

 as is made where a current of water is obstructed by some obstacle ; 

 the current pushes some distance up the obstruction and then breaks 

 over the sides to go around it ; but ice, being much less fluid than 

 water, moves off in larger swells and more gradual curves" (p. 95). 

 A simple computation of the momentum of the glacier and of the ratio 

 of this to basal friction is sufficient to reveal the absurdity of attribut- 

 ing this phenomenon to momentum. There is a special infelicity in 

 citing fluidal action by way of illustration, since it is quite clear that it 

 is the element of rigidity in the ice, acted upon by pressure from 

 behind, that produced the upthrust. 



Perhaps the observations of Professor Wright on icebergs should 

 be included among the original contributions of the volume to the 

 glacial phenomena of Greenland. Icebergs were encountered — liter- 

 ally in one case — in large numbers and quite unusual dimensions and 

 they are very graphically described. The one with which the 

 Miranda collided is said to have "towered hundreds of feet above 

 us" (p. 6), and another was estimated "to have pinnacles which rose 

 more than 700 feet above the water" (p. 3). In the minds of those 



