422 The National Geographic Magazine 



St Pierre. Ruins of the Great Distillery in the Fort Quarter of the City, 

 Showing Holes in the Iron Tanks due to Volcanic Bombardment 



From a photograph by Dr E. O. Hovey. Republished from the Bulletin of the American 



Museum of Natural Historv 



L,a Souf riere was in full blast something 

 like 48,000,000,000 cubic feet of dust- 

 and stone-laden steam were driven out. 

 Onl} T guesses can be made as to the 

 amount of solid matter the steam con- 

 tained. Shall we assume 1 per cent or 

 10 per cent ? Most observers would 

 agree, I fancy, not only that the latter 

 was nearer the truth than the former 

 estimate, but that the true measure is 

 in excess of the larger of the two. 



The material extruded in a solid con- 

 dition, as will be shown later, is fresh 

 lava which came from deep within the 

 earth ; but mingled with it are rock 

 fragments that were torn from the walls 

 of the conduits through which the dis- 

 charges occurred. The per cent of 

 old lava among the ejected solids seems 

 to be greater on St Vincent than on 



Martinique. In harmony with this is 

 the larger size of the crater of La Sou- 

 friere in comparison with that of Mont 

 Pelee. 



The columns of steam of Kennan's 

 t} r pe No. 4 thus show that great vol- 

 umes of rock are rising from deep 

 within the earth and being blown into 

 the air. If, as seems probable, the 

 energy displayed by steam columns of 

 the No. 2 type is all that can be sup- 

 plied by the steam produced from rain 

 and percolating water in the upper part 

 of the conduit, it follows that during 

 explosions of the No. 3 type both rock 

 and steam are rising from a depth in 

 the volcanic conduits. Presumabty 

 then, during eruptions of the types No. 

 3 and No. 4 molten rock is being forced 

 up within the conduit of a volcano and, 



