June, 1920] The Great Mageik Landslide 353 



growing smaller as they descended. The behavior of this head- 

 long mass resembled the rush of a headlong torrent. Although 

 bowlders measuring 10 meters or more in diameter were mixed 

 up with finer matter, as a whole the movement approximated to 

 that of a fluid. No words can describe the fierceness and force 

 of that impetuous downpour — it made surgings this way and 

 that, and the bold leaps with which it would now and then 

 bound over low ridges that hindered its progress, and shoot 

 onward down the neighboring depression. 



"In like manner probabW, but on a vastly more gigantic 

 scale, the stream of materials on the 15th of July ran down 

 the slopes of Bandai San, dividing as it went into two princpial 

 branches. " 



It is to be noted that although this second flow was described 

 as essentially similar to the first, there is in this case not the 

 least hint of a volcanic disturbance connected with its cause. 

 It is described as a typical rock fall, pure and simple, yet it is 

 recognized as practically identical with the great eruption. 



The eruption was accompanied by a great cloud of dust 

 which, the authors carefully explain, was essentially different 

 from the pumiceous ash of an eruption like Krakatoa, for it 

 consisted merely of fragments of finely pulverized rock, i. e., 

 it was a typical dust cloud such as always accompanies a land- 

 slide. In every detail their description and figures show the 

 features of a landslide. They go on (p. 110) as follows: "Among 

 the various phenomena that constantly bewilder the eyes of 

 visitors to the seat of the eruption, not the least striking are 

 the numerous big bowlders, some of them measuring from five 

 meters to ten meters each way, that are to be seen resting on 

 the surface of the debris far away from the crater. These have 

 evidently been carried along as part of the mud current, and 

 not hurled through the air. Not less curious are the quantities 

 of small cones, varying from a few meters up to 15 meters in 

 height, which are scattered here and there over the surface, 

 standing out of the debris like so many miniature Fujiyamas." 



Their drawings of these innumerable cones studding the 

 surface of the flow are perhaps even more striking than the 

 photographs accompanying the present article. 



The velocity of the Bandai San Slide was tremendous. Our 

 authors estimate it as 77 kilometers, or 48 miles, per hour. It 

 was accompanied by terrific wind blasts which overthrew 



