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



Yet, on a warm day when the snow melt is large, Martin Creek 

 is too big to ford. There can be no question, therefore, but 

 that the greater part of the precipitation that falls in the 

 drainage basin tributary to the Valley is returned to the air 

 by evaporation. 



Having ascertained this fact, we set out to see if we could 

 follow the wa.ter cycle from precipitation to vaporization. In 

 part this was easy. Whenever rain falls on the hot floor of the 

 Valley it is immediately converted into vapor and returned to 

 the air. During a rainstorm the Valley fairly reeks with the 

 hot steam which is everywhere poured back into the saturated 

 atmosphere. If one investigates the melting snowdrifts 

 which fringe the Valley, he finds innumerable trickling rills 



Photograph by R. F. Griggs 



A BIG VENT FAR DOWN THE VALLEY. 

 The man silhouetted against the steam gives the scale, but only part of the steam 

 column is shown, illustrating the magnitude of the vents which must be 

 accounted for. This volcano is located 8 miles from Novarupta, where the 

 activity of the Valley reaches its climax.' 



which start down from them, but they soon suffer the same 

 fate as the pattering raindrops. Before they have crossed 

 many yards of the hot earth, their waters become warm and 

 dry up without having the opportunity to unite into a stream 

 large enough to furnish water for a fumarole of any size. The 

 larger streams likewise shrink so gradually that one cannot 

 find a notable diminution in their volume in any particular 

 place; that is to say, the vapor from their waters is given off 

 diffusely along their whole length. When one considers the 

 very large areas of the Valley where the ground stands at a 

 temperature approximating the boiling point, it will be seen 

 that its surface has the capacity of evaporating an enormous 

 volume of water in addition to the great volumes of steam 

 which come up from the specialized vents. 



