354 REACTION OF THE INTERIOR OF THE EARTH 



adjacent granite, deserve to be examined by an observer 

 well acquainted with modern geological science, and the 

 mineralogical composition of the rocks to be accurately 

 investigated. Of the two islands of the Pribytow group, 

 which stand a little apart by themselves iD Bering's sea, 

 St. Paul's is entirely volcanic with much lava and 

 pumice ; although, on the other hand, St. Greorge's only 

 contains granite and gneiss. 



According to the most complete accounts which we at 

 present possess, the range of the Aleutian Islands, 960 

 miles long, appears to contain upwards of 34 volcanoes, 

 most of which have been active within recent historic 

 times. Thus, we have here (within 54 and 60 N. lat, 

 and 160 to 196 W. long.) a strip of the whole sea bot- 

 tom between two great continents in a state of constantly 

 alternating, formative and destructive activity. Here, 

 as in the Azores, in the course of thousands of years 

 many islands may have been elevated to near the surface 

 of the sea, yet without having actually risen above it, 

 and many may long since have appeared and have sub- 

 sided again, either wholly or partially unobserved. For 

 the migration and intermixture of races and people, the 

 Aleutian Islands offer a route 13 or 14 degrees south 

 of that by Bering Strait, by which the Tschuktsches 

 seem to have passed from America to Asia, and even to 

 beyond the Anadyr River. 



The range of the Kurile Islands, extending from the 

 extreme point of Kamtschatka to Cape Broughton 

 (the north-easternmost promontory of Jezo), a length of 

 720 geographical miles, has 8 or 10 volcanoes, most 

 of which are still burning. The northernmost of these 

 in the island Alaid is known for its great eruptions 



