374 BOGOSLOF VOLCANOES. 



Captain Tanner, who had been tfiere the previous year, expressed 

 surprise at the altered appearances. Not only had the connecting 

 spit disappeared, but the island had decreased in height at least 100 

 feet, and the pinnacle had fallen and was lying* in huge masses on the 

 steep incline. 



In 1895 Bogoslof was visited Irr Becker and Dall, of the U. S. Geo- 

 logical Survey. The}^ found the activity of the steam vents greatly 

 diminished and the top of the volcano lowered and flattened. This 

 flattened plateau-like form has continued, and is excellently shown in 



VIS — 

 Pig. 11.— The islands from u little east of north in 1S'J7. Fruiu photograph by Dr. L. stejneger. 



the accompanying illustration from a photograph taken by Dr. Leon- 

 hard Stjeneger in 1807 (tig. 11). 



In 1809, when seen by the Harriman expedition, no change was 

 observed. 



SUMMARY. 



Accounts of early navigators and traditions of native Aleuts agree 

 that long before the upheaval of the modern volcanoes a large pillar- 

 like rock stood in the place now occupied by Bogoslof Islands. The 

 dwindling remnant of this large rock, known as Ship Rock, whose 

 position was between the present islands, fell in 1888 or 1889. In 

 early times it must have been partly surrounded by low rocks or 

 spits, for it was always a great resort of sea lions, and these animals 

 do not remain about perpendicular rocks in the open ocean, where there 

 is no place to land. 



In 1796 a volcanic island (Old Bogoslof) was upheaved about half a 

 mile southeast of Ship Rock. For some years it increased in size and 

 then slowly cooled, after which it began to weather and disintegrate, 

 and to be torn away by the sea. 



In 1883 a new volcano appeared close to Ship Rock, but on the oppo- 

 site (northwest) side. Its summit for the first few years was moun- 

 tainous and irregular, but between 1891 and 1895 it became flattened 

 and plateau-like. 



For six years (1884-1890) Old and New Bogoslof were completely 

 connected by a broad spit, or isthmus. 



