180 The Ohio Journal of Science [Vol. XIX, No. 3, 



volcano. That the blasts should have retained their power at 

 such distances is the more remarkable because the intervening 

 country is covered with high mountains, which must have 

 offered great obstruction to their passage. So far as the writer 

 is aware, this is the greatest distance which has been recorded 

 as having been reached by volcanic blasts. 



If then, it may be considered that the evidence available is 

 sufficient to establish definitely the presence of destructive 

 blasts at distances up to 25 miles from the volcano, it might be 

 argued a fortiori how very violent they must have been close 

 to the crater. But it would not be safe to make such an 

 assertion, especially since there appears to have been at least 

 one important difference between these blasts and most of those 

 previously described. 



One of the most striking features of the hot blasts from 

 Pelee, Taal and Lassen is the extreme localization of their 

 effects. In each case only a narrow radial sector of the country 

 around the crater was effected, and the edges of this sector were 

 sharply denned. 



The most striking feature of the blast from Katmai, on the 

 other hand, is its general distribution around the whole of the 

 circumference of the crater. Not only did it spread in all 

 directions from the crater, but the distance to which it retained 

 its destructiveness was remarkably uniform, being about 

 25 miles almost everywhere that it has been observed, 

 with little regard to the character of the intervening country. 

 It was almost as destructive at Amalik Bay, across the moun- 

 tains, as in the Valleys of Katmai and Ukak Rivers which 

 radiate almost directly from the volcano. The only exception 

 to this condition observed was on the southwest, where the 

 destruction of trees was limited by the divide at the head of 

 Martin Creek, which stands somewhat nearer the volcano. 



NATURE OF THE BLAST. 



The question of the nature of the devastating blast from the 

 volcano is more difficult to answer from observation so long 

 after the event, but there are a few lines of evidence which may 

 be stated even though it may not be wise to draw positive 

 conclusions. Were poisonous gases given off, or was the 

 destruction due to the high temperature of the blast? 



