252 DUMOULTN ISLANDS. 



Islands proved to be inhabited^ and the natives 

 exhibited no hostile feeling' towards the Bramble's 

 people. A specimen of the rock^ taken from the 

 shore and given me by Lieutenant Yule^ is a very 

 curious siliceous breccia ; when viewed from the sea 

 I had observed the cliffs to exhibit horizontal and 

 vertical fissures — apparently lines of cleavage — as 

 I had seen assumed on various occasions during our 

 last cruize by granite and porph}Ty. This^ at 

 least^ indicated a great approaching change in the 

 geological structure of the New Guinea Islands^ 

 contrasted with those of the Louisiade Group which 

 had come under our observation. 



