CALCULATING THE HEIGHT 



400 ft. deep. The crater wall opposite the one at the 

 top of which we were standing presented features of 

 special interest. Beds of dark pumiceous lava or pumice 

 alternated with white zones of snow. There was no 

 direct evidence that the snow was bedded with the 

 lava, though it was possible that such may have been 

 the case. From the top of one of the thickest of the 

 lava or pumice beds, just where it touched the belt of 

 snow, there rose scores of small steam jets all in a row. 

 They were too numerous and too close together to 

 have been each an independent fumarole; the appear- 

 ance was rather suggestive of the snow being converted 

 into steam by the heat of the layer of rock immediately 

 below it." 



While at the crater's edge the party made a boiling- 

 point determination by the hypsometer, but the result 

 was not so satisfactory as that made earlier in the 

 morning at the camp. As the result of averaging- 

 aneroid levels, together with the hypsometer deter- 

 mination at the top of the old crater, Erebus may be 

 calculated to rise to a height of 13,370 ft. above sea- 

 level. As soon as the measurements had been made 

 and some photographs had been taken by Mawson, the 

 party returned to the camp, as it had been decided to 

 descend to the base of the main cone that day, a drop of 

 8000 ft. 



On the way back a traverse was made of the main 

 crater, and levels taken for constructing a geological 

 section. Numerous specimens of the unique felspar 

 crystals and of the pumice and sulphur were collected. 

 On arriving in camp the travellers made a hasty meal, 

 packed up, shouldered their burdens once more and 

 started down the steep mountain slope. Brocklehurst 

 insisted on carrying his own heavy load in spite of his 

 frost-bitten feet. They followed a course a little to the 



185 



