ON THE GLACIER 



bankments. Unfortunately for our progress, the trend 

 of the latter was nearly at right angles to our course. 

 As we advanced still further north the undulations 

 became more and more pronounced, the embankments 

 higher and steeper. These embankments were now 

 bounded by cHfFs from forty to fifty feet in height, 

 with overhanging cornices of tough snow. The cliffs 

 faced northwards. The deep chasms which they pro- 

 duced formed a very serious obstacle to our advance, 

 and we had to make some long detours in order to head 

 them off. On studying one of these chasms it seemed 

 to me that their mode of origin was somewhat as follows : 

 In the first place the surface of the ice had become 

 strongly ridged through forward movement of the 

 glacier, with perhaps differential frictional resistance; 

 the latter causing a series of undulations, the top of 

 each ice undulation would then be further raised by an 

 accumulation of snow partly carried by the west-north- 

 west plateau wind, partly by the southerly bhzzard 

 wind. These two force components produced these 

 overhanging cliffs facing the north. For some reason 

 the snow would not lie at the bottoms of the troughs 

 between the undulations. Probably they were swept 

 bare by the plateau wind. It was hardly to be wondered 

 at that we were unable to advance our sledges more than 

 about one mile and a half that day. 



The next day, December 1, the hauling of our sledges 

 became much more laborious. For half a day we 

 struggled over high sastrugi, hummocky ice ridges, 

 steep undulations of bare blue ice with frequent chasms 

 impassible for a sledge, unless it was unloaded and 

 lowered by Alpine rope. After struggling on for a little 

 over half a mile we decided to camp, and while Mawson 

 took magnetic observations and theodolite angles, 

 Mackay and I reconnoitred ahead for between two and 



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