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



catastrophe. (3) The soil on the mountain top was a very thin 

 layer as compared with the great thickness of rock which fell 

 away. The quantity is altogether too small to suffice to 

 lubricate the bed of the coarse rock. The evidence seems to 

 require, therefore, that we hold that this striking liquid char- 

 acter was inherent in the whole mass. 



We are not in a position to analyze the situation sufficiently 

 to permit of an explanation of the matter, but some considera- 

 tions may be adduced which may make it seem less impossible. 

 An ordinary liquid like water buoys up any solids immersed in 

 it, and the buoyancy thus imparted, to them is equal to the 

 weight of the liquid which they displace. Examination of the 

 slide indicates that during the period of its fluidity it had sim- 

 ilar properties. The position of certain of the rocks imbedded 

 in the mass can indeed hardly be explained on any other basis. 

 In some cases a bowlder, several feet in diameter, surrounded 

 entirely by finer material, was carried up to the very edge in 

 such fashion that by no stretch of the imagination could it be 

 considered as having slid or fallen into place, but must have 

 floated into position. Since, moreover, the specific gravity of 

 this liquid was much greater than that of water, its power of 

 flotation must have been correspondingly increased. This 

 becomes especially significant when it is recalled that the specific 

 gravity of the liquid approached closely to that of the stones 

 which it carried. Thus, while the density of the liquid may 

 have been only twice as great as water, its power of flotation, 

 which is measured by the difference between the speciflc grav- 

 ities of the load and liquid, was very great. When, in addition 

 to this, it is remembered that the transporting power of a liquid 

 increases with the sixth power of its velocity, and that the slide 

 probably had a velocity much higher than that of any ordinary 

 stream, its curious behavior may perhaps be better understood.* 



On looking up the literature on my return from the fleld, I 

 find my opinion confirmed by eye-witnesses of the Elm land- 

 slide, which was evidently closely similar to the present one. 



*Sekiya and Kikuchi, as quoted below, give the velocity of the slide at Bandai 

 San as 48"miles per hour, while the flood current of a great river seldom exceeds 

 7 miles per hour. In other words, the transporting power of a stream with the 

 velocity of the slide would be more than 100,000 times as great as that of an ordi- 

 nary flood. It is doubtful if the numerical comparison would hold where the 

 conditions are so different. No attempt should be made to apply it numerically, 

 but the statement gives a lively idea of the possibilities in this direction. 



