352 



The Ohio Journal of Science [Vol. XX, No. 8^ 



a mass of some 1.21 cubic kilometers, or 1,587 millions of cubic 

 yards, which was the actual volume of the mountain destroyed, 

 of sand to be suddenly precipitated from a lofty summit, it 

 would flow down the sides in a torrent not very unlike that of 

 water. That the earth and rock debris did flow down in this 

 way we were convinced by examining the actual state of things 

 on the spot, and more particularly by witnessing afterwards 

 with our own eyes a ver}' similar phenomenon, though on a 

 vastly smaller scale. 





■,-^■■■■ 



a'aiL.^ 





;^:^' 



Photograph by Robert F. Griggs 



A CONE MADE UP ENTIRELY OF SANDSTONE. 



Since sandstone forms only a very small percentage of the material of the slide as 



a wnole, a pile like this composed exclusively of sandstone seems best 



interpreted as the remains of a single large sandstone block, 



which was much broken up. but not scattered, in its 



course down the valley. 



"One day, while we were at work in the crater, a huge slice 

 of the precipitous w^all of rock that had been bared by the 

 explosion, fell suddenly and crashed with a tremendous uproar 

 down the steep incline beneath. This slab fell from a place 

 about 300 meters high. The great masses of earth and rocks 

 were shattered as thev fell and broken up into pieces ever 



