Dec., 1918] Are the Ten Thousand Smokes Real Volcanoes? 103 



steam is so rapid that it fairly purrs as it comes rolling out. 

 Many of the smokes with smaller throats issue under such 

 pressure as to emit a continuous low-toned roar. In some of 

 them the rush of the emerging steam is so rapid that a pebble 

 tossed into them is either immediately spewed out again or 

 sinks slowly down against the rushing current of rising steam. 

 The supply of water necessary to maintain a constant flow of 

 steam of such dimensions is, of course, considerable. Multiplied 

 by the number of the big vents, it -becomes enormous. Now, 

 the visible surface water which is dissipated by diffuse evapora- 

 tion appears to be great enough in volume to account for 

 practically all of the drainage from the water-shed tributary 

 to the Valley. One who sought. to establish the presence of 

 underground streams of sufficient size to produce the smokes 

 observed would have considerable difficulty, therefore, in 

 fjmding a source for such a quantity of water. 



NO LAVA FLOW TO VAPORIZE GROUND WATER. 



If the smokes are due to the vaporization of surface or 

 ground water by a mass of hot lava poured out on the ground 

 at the time of the eruption, it should be easy to find the lava 

 flow beneath the fragmental ejecta which cover the surface. 

 But none is to be found. There is absolutely no indication of 

 any lava flow anywhere in the Katmai district other than the 

 ancient basalts of which the volcanoes were built up. In many 

 places deep canyons have been cut by the streams into the 

 surface of the Valley, but nowhere is there the slightest indica- 

 tion of lava beneath. If there were a cooling lava flow close 

 beneath the surface, the bottoms of these narrow canyons, 

 which are 50 to 100 feet deep, (see page 118), should be much 

 hotter than the surface of the ground, but such is not the case. 

 These gorges are like any other part of the Valley. Locally 

 they may be very hot, but these hot spots are always obviously 

 associated with some special vent in the vicinity. 



It is not only impossible to find any lava flow, but it is 

 equally difficult to locate any vent from which such a stream 

 might have come. Certainly it could not have come from the 

 crater of Katmai. The low points in its rim are all occupied 

 by glaciers which antedate the eruption, being covered by the 

 same layers of ash as are found everywhere throughout the 



