,-o DISCOVERY REPORTS 



the latter will be reflected in our charts of positions. During most of the period under 

 review there were, however, enough factories employed to cover the whole ground 

 adequately; and since their movements were determined by the positions in which 

 whales were most abundant, we think the limitations to the data are much the same as 

 those on the South Georgia grounds — we believe that within the area examined no 

 large concentration of whales could have existed without being discovered. Heavy 



Fig. 2. The South Shetland whaHng area. 



pack-ice will naturally limit the movement of the factories, but it will equally limit the 

 movements of the whales ; for while whales— Blue whales in particular— often concen- 

 trate along its margin, they will not penetrate it unless sufficiently open to permit the 

 passage of a vessel.^ 



1 Captain Jorgen 0re, a veteran among South Shetland whalers, has told us that at the beginning of season 

 1914-15 he met impenetrable pack-ice, of extreme thickness and with many included icebergs, far to the 

 north of the islands. He sent his catchers long distances afield to look for an opening; but they could find 

 none, and for some time he worked along the ice-edge, taking Blue whales in good numbers. Then one day 

 the whales vanished : he realized at once that a passage to the south must have opened, and next day he found 

 a way through to Bransfield Strait. 



