Dr Martens on the Glaciers of 'Spitsbergen. 287 



cle, the arc of which, as well as the two extremities of the 

 cord, rest on the bank. 



1*7, If the glaciers descended to the bottom of the sea, we 

 ought to meet with some of them whose upper surface was 

 washed by the waves ; this surface would form an inclined 

 plane which would form an angle more or less open with that 

 of the sea. But this we never witness ; the glacier always 

 terminates in a vertical wall of considerable height. 



2d, When it is ebb-tide, we would not be able to distinguish 

 any interval between the ice and the water ; an interval which 

 is everywhere observable along the glacier. But, it may be 

 ?aid, the glacier rests on the bottom of the sea, and the ver- 

 tical wall which terminates it is entirely hollowed out from 

 the level of its surface by the action of the waves. If this hy- 

 pothesis were true, we would notice at the foot of the glaciers 

 hemispherical cavities analogous to those in all the floating 

 masses of ice, or we would always perceive the submerged ice 

 beneath the water which was washing it .away. But nothing 

 of this nature appears in these glaciers. The line terminating 

 their lower surface is perfectly straight, continuous, horizon- 

 tal, and consequently parallel with the level of the sea. Of 

 this I assured myself by sailing round the glacier of Magda- 

 Iena Bay. I entered with the boat into the creeks formed in 

 the glacier itself by the falling down of the ice, and in no in- 

 stance did I notice submai'ine ice. 



3d, When a considerable mass becomes detached from the 

 glacier, it always extends to its entire height ; it is, so to speak, 

 a portion of the glacier separated from the rest. If it touched 

 the bottom it would slide or tumble merely ; but we see it for 

 the most part plunge almost vertically, and remain for a few 

 seconds under the water before it reappears at the surface. 



Ath, By ascending the terminal glacier of Magdalena Bay, 

 1 saw distinctly that it was depressed towards the middle, and 

 very concave in all that part which slopes to the sea. 



bth, In proportion as the glacier is broken, the escarpment 

 in which it terminates lias the tendency to describe a curve 

 more or less parallel to that of the shore, because the central 

 parts, which are not supported, are the first to break down. 



(jth, Another argument is derived from the height of the 



