1853.] SUTHERLAND ARCTIC REGIONS. 303 



the freezing-point of water would settle the question. We know that 

 the sea exerts a wonderful influence in rendering the climate tempe- 

 rate, as well as in reducing the ranges of temperature. Upon this 

 theory, so clearly illustrated in Sir Charles Ly ell's 'Principles of 

 Geology *,' the summer in the neighbourhood of Barrow Straits ought 

 to be hotter than in Davis' Straits. And such we find it, as far as 

 our limited observations can be made available. The month of 

 July 1851, at Cornwallis Island, was found to be three degrees 

 warmer than the same month of the preceding year in a correspond- 

 ing latitude on the east side of Davis' Straits. This difference is 

 certainly small, but still it is on the favourable side ; and when we 

 associate with it the different structure of the rocks and also the 

 diminished supply of vapour during the winter months, we have a 

 faint approximation to the true cause why the glacier prepon- 

 derates so largely in one direction, while it is entirely absent in 

 another. The fact too that large sections of the coast -ice, before 

 it was generally detached from the land, became dissolved by the 

 streams discharging the melting snows of the North Georgian Islands 

 into the sea, may be taken as an additional proof that the summer 

 heat was positively higher than was necessary for the conversion of 

 snow into water. 



Glaciers. — The travels of Prof. J. Forbes and of Agassiz in the 

 Alps have so fully established the true theory of the descent of gla- 

 ciers, which is applicable also to Greenland, as to render any remarks 

 on this head almost unnecessary. The introduction of extraneous 

 matter into the substance of the ice to be borne along must be the 

 same in every country (fig. p. 301, akb (Sketch No. 2), and Sketch 

 No. 7, b). And so also must be the deposition of moraines at the 

 angles where the glacier begins to protrude beyond the land, whether 

 they occur at the sea-level, or at rapid turnings at higher elevations. 

 This deposition arises from the dissolution of a portion of the ice 

 rich in earthy matter consequent upon increased freedom of expo- 

 sure to the action of the sun, and also from mechanical displacement 

 of the rocky matter by the advancing mass of the glacier. This was 

 remarkably well seen at the north side of the Petowak glacier, near 

 Cape Atholl, both at the sea-level and at an angle two miles further 

 up the side of the glacier. 



The concentric and wavy appearance of the glacier-surface so often 

 noticed in the Alps, is remarkably well seen in the vicinity of Cape 

 Saumarez (Sketch No. 7, b) and of Cape Alexander (Sketch 

 No. 8, b), and also in Bardin Bay (Sketch No. 6, c). 



Both Prof. Forbes and Agassiz agree in attributing the roughness 

 and irregularity of the surface of the glacier to the inequalities of 

 the bottom over which it has to pass, more especially in cases where 

 the action of the sun has not been distributed irregularly by means 

 of accumulations of extraneous matter. This is frequently exempli- 

 fied in the Arctic regions ; and, as in the Alps, large crevasses are 



* Principles of Geology, Seventh Edition, chap, vi. 



