& Powers — Volcanic Domes in the Pacific. 271 



Perry Peak (Metcalf Peak) appeared in March, 1906, as 

 an island 2,000 feet in diameter and 400 feet long, near the 

 site of Ship Pock, midway between Castle Rock and Fire 

 Island. The sides of the peak were quite smooth and the 

 top was described as a "broken horn" as if the mass had 

 been forced through an aperture in the submarine volcano. 

 Gas must have accumulated in large quantities within the 

 cold exterior of the spine, for after an existence of 10 months, 

 an explosion blew away half of it. 



Soon after the destruction of half of Perry Peak, a similar 

 spine, McCulloch Peak, rose close by, partly over the place 

 which the destroyed half of Perry Peak had occupied. The 

 size of McCulloch Peak, when visited in August, 1907, was 

 about that of the original Perry Peak. The shattered cross- 

 section of the latter showed a central spine, like that of Mont 

 Pelee, surrounded by debris which had fallen from and which 

 had been blown from the sides and top of the spine during 

 its upthrust. 15 



The life of McCulloch Peak, like that of Perry Peak, was 

 10 months, for an explosion destroyed the entire mass in Sep- 

 tember, 1907, piling high with debris the sand bars which 

 had formed between Castle Pock, Fire Island, and the remnant 

 of Perry Peak. 



During the next few years the changes at Bogoslof are 

 uncertain, but in July, 1908, it was reported that no trace 

 of Perry Peak was visible, suggesting another explosion. On 

 September 10, 1909, the bay which occupied the site of 

 McCulloch Peak and of Perry Peak was reported to have 

 become a lagoon in which two small islands had appeared. 

 These islands continued to rise, so that in June, 1910, the 

 larger was 178 feet in height, and the smaller 100 feet. 



The lower peak was named Tahoma Peak in honor of the 

 U. S. S. Tahoma, but the higher one is referred to as Perry 

 Peak. On September 18 an explosion opened a crater 

 in the higher peak, and ashes together with clouds of smoke 

 and steam were ejected. The formation of a crater — so rare 

 a phenomenon at Bogoslof — may- have been caused by a more 

 gradual escape of the confined gases than in the cases of Perry 

 and McCulloch peaks. 



15 T. A. Jaggar, Jr., Bull. Amer. Geogr. Soc, vol. xl, pp. 385-400, 1908. 

 The earlier history of the volcano is described by C. H. Merriam, Harriman 

 Alaska Expedition of 1899, vol. ii, and Smithsonian Kept, for 1901, pp. 

 367-375. 



