6 INTRODUCTION. 



McMurdo Sound is therefore approximately rectangular in shape, the long and the short sides 

 being fifty and forty miles respectively ; it is open to the Ross Sea on the north and closed 

 by the Barrier to the south. The Sound has open water during .January and February, 

 but freezes over during the winter. The winter conditions of the ice are however very varied 

 from year to year. During some winters the whole Sound is frozen over from April to 

 the end of December, while during other winters frecjuent gales remove the ice as soon as 

 it is formed and only the southern half becomes firmly frozen over. 



The summit of Mount Erebus is about fifteen miles to the north-ea.st of Cape Evans, 

 and is over 13,000 feet high. The side of the mountain in this region rises rapidly from 

 the coast and is covered with one huge glacier. Cape Evans is a small triangular piece of 

 land at the foot of the mountain. One side of the triangle is against the slopes of Erebus 

 while the other two are washed by the waters of the Sound. During the summer a large 

 propoi'tion of the black volcanic debris of the Cape is exposed, but in the winter it is all 

 covered by snow except in a few places where the wind sweeps the surface clear. The slopes 

 of Erebus to the south of Cape Evans are cpiite impas.sable, hence when the sea is not 

 frozen over Cape Evans is entirely cut ofl' from the south. When the Sound is frozen over 

 the sea ice forms a splendid surface over which the coast of Victoria Land can be reached 

 or journeys made to the south. 



It was mentioned above that McMurdo Sound is closed to the south by the Great Ice 

 Barrier. As a comparison of the conditions at Cape Evans Avith those on the Barrier will 

 form an important part of this work, it is essential that the geographical features to the 

 south of Cape Evans should be thoroughly understood. We have already become familiar 

 with the great surfaee cf the Barrier extending southwards from the icc-clifEs which form 

 the southern limit of the Ross Sea. The edge which the Barrier presents to McMurdo Sound 

 is much less imposing than that to the Eoss Sea, for the latter is a cliff of ice approxi- 

 mately 100 feet high, whi'e the end of McMurdo Sound is closed by a clifi only a few 

 feet high and this is in many places, especially at the end of the winter, almost obliterated 

 by snow-drifts which foim inclined planes from the Barrier surface to the sea ice. The edge 

 of the Barrier ice is shown in figure 2. It will be seen that it extends from near Hut 

 Point in a zigzag line to the coast of South Victoria Land just to the north of the Koettlitz 

 Glacier. The position of Hut Point is also of considerable importance as it was here that 

 the Discovery Expedition had its headquarters in 1902-04. The hut itself was situated 

 on a .small cape around which open water extends during most summers. It is possible 

 however to reach the Barrier from Hut Point even when the sea is not frozen, for a way 

 leads over land from the hut to the po.sition where the Barrier permanently joins the land. 



Details of the exposure of the instruments and the lie of the land at both Cape Evans 

 and Hut Point will be considered as occasion arises in the discussion of the observations. 



Cape Evans to the Pole. — A great number of meteorological observations were made on 

 the sledging journeys undertaken in connection with the attempt to reach the Pole ; it is 

 therefore desirable that the route taken on those journeys should be described here. The 

 first pari of the journey was from Cape Evans to Hut Point. This could only be under- 

 taken when McMurdo Sound was frozen over. The hut erected at Hut Point by the Dis- 

 covery Expedition w^as used as a base for all journeys further south and here it was possible 

 for various parties to wait while the Sound froze over or until the time arrived for con- 

 tinuing their journey. From Hut Point the Barrier was reached either over the sea ice 

 to Safety Camp, or through ' the Gap ' ; then, in order to miss crevasse.' formed in the 

 Barrier ice by the Bluff, the course was laid east-south-east to Corner Camp in 77° 54' S., 

 167° 17' E. From Corner Camp the journey to the Beardmore Glacier was made along 



