DESCRIPTION OF THE ISLANDS: SOUTHERN THULE GROUP 



179 



Islands are covered deep in glacier and the way in which they have been formed would 

 probably have been misinterpreted, or have remained obscure, were it not for an inter- 

 esting discovery which we owe to our echo-sounding apparatus. With this apparatus we 

 found that a very deep basin exists between Cook and Thule Islands in Douglas Strait.^ 

 In the middle it has soundings of over 400 fathoms, while at the north and south 



4S 46 " n 



91 „ 



1» 15(, 1,2 



SEA mix 



42 60 f>9 71 '9 



Fig. 16. Chart of Douglas Strait, Southern Thule, showing 

 soundings in the submarine crater. 



entrances there is less than 20 fathoms. That the basin was once a volcanic crater 

 scarcely admits of doubt. It is probable that by its eruption it originally formed one 

 large island, and that of this island Cook and Thule are the only portions now 

 remaining. 



1 Rear-Admiral H. P. Douglas, C.B., C.M.G., member of the Discovery Committee. 



