118 



The Ohio Journal of Science [Vol. XIX, No. 2, 



I have thus entered into a somewhat personal statement of 

 thejmatter because I must expect my readers, at least those who 

 have any previous acquaintance with volcanoes, to assume the 

 same attitude and would bespeak in advance their careful 

 consideration to the end, rather than the unceremonious rejec- 

 tion which would otherwise be the fate of the account. 



Photograph by R. F. Griggs 

 A CANYON NEARLY 100 FEET DEEP, CUT INTO THE MUD FLOW. 



Although this section is located far down the Valley, it shows no indication of the 



bottom of the mud flow. The thin strata of the Katmai ash may be 



seen near the top. The figure at the left gives the scale. 



