164 



Me 



ssrs. 



R. M. Deeley and P. H. Parr 



Owing to these considerations it would appear that at 

 section V. the interior ice of the Hintereis Glacier is not- 

 affected appreciably by the summer heat, even near the 

 surface, and that we must regard the ice at section V. 

 as being about equally " dry " throughout. However, it 

 may be that there is more interstitial water in the ice near 

 the bottom than at the surface, owing to the greater shear 

 that takes place there. On the other hand, the temperature 

 of the snow which forms the glacier ice may be so low that 

 the interior ice of the glacier is never raised to the melting- 

 point by the internal friction. 



Bliiincke and Finsterwalder measured the variations of 

 velocity on the glacier tongue during a period of several 

 years. Their results, as exhibited by their observations made 

 at points some distance from the glacier sides, have been 

 plotted, and the diagram (fig. 8) constructed to show the 



Pig. 8. 



changes of velocity that occurred in the glacier tongue. At 

 a distance of 2775 metres from the end of the glacier the 

 velocity reached a minimum early in 1901. This minimum 

 shows itself at a point 396 metres from the end of the glacier 

 early in 1903. The dotted line shows, approximately, the 

 rate of retreat of the glacier snout, a decreasing velocity of 

 the ice being accompanied by an increased rate of retreat,, 

 and vice versa. 



It is now recognized that variations of the velocity of a 

 glacier tongue are generally due to a general lowering of 

 the snow-line and not to increased precipitation. Of course, 

 increased general precipitation would lower the snow-line, 

 but glacier advances are not generally due to this cause. In 

 some cases where the precipitation had been temporarily 

 greater than usual, it would appear that the damp winds 



