i86 



DISCOVERY REPORTS 



been worn away by ice action. No measurements were taken of the glacier face, but 

 there is no doubt that it is fully as thick as on Bristol Island. 



As already explained (p. 179) the crater from which both Cook and Thule originated 

 is probably that now submerged beneath the sea in Douglas Strait. The two are thus 

 fragments of a single much larger island, which in size must have approached Montagu 

 — now the largest of the group. 



All round the coast is precipitous, alternating between steep rugged clifTs with glacier 

 hanging above them and glaciers reaching to the water's edge. If small ice-falls down 

 the hill-sides are omitted, there are in all eight glaciers which reach the sea, the largest 

 being half a mile in breadth. The most extensive rock exposures are to be found 



Fig. 20. Cook Island: sketches by Lt.-Cmdr. J. Irving. 



a. From the W: Reef Point on the right bearing 1 10°, distant about 2 miles. 



b. From the NE; Swell Point on the left bearing 203°, distant 3-6 miles. 



c. From the SW: Reef Point on the left bearing 009°, distant i mile. 



d. From the S: Jeffries Point to right of centre bearing 000°, distant 3 cables. 



bordering Douglas Strait, and in the south-east between Swell Point and Jeffries Point. 

 The rocks here, and indeed at all points where they are visible, are yellow, red or brown 

 in colour, sometimes showing signs of stratification, but always very much crumpled 

 and contorted, often seamed with dykes of grey rock and sometimes apparently with 

 large intrusive masses of brown material showing vertical striation. 



Cook Island differs from all the others of the group except Leskov in that, so far as 

 we were able to observe, penguins are entirely absent. They are certainly extremely 

 scarce, and this is evidently due to the very steep coast which is at no point suitable for 

 a rookery. On the high cliffs facing Douglas Strait, myriads of Silver-grey petrels were 

 perched and we think it more than probable that they nest here. 



There is no record of any landing on the island. 



