241 R. T. HILL — PELE AND THE WINDWAKD AKCHIPELAGO 



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Interior theory of vulcanism 281 



Eecent views on the condition of the earth's interior 281 



Arrhenius' theory of a gaseous center 282 



Source of the water of vulcanism 284 



Theory of linear arrangement along fissure lines 286 



The magmatic hypothesis 287 



Introduction 

 volcanic eruptions of 1902 and* how they were studied 



Three years have passed since the cataclysm of mont Pele recalled to 

 the world the existence of the Caribbean islands and their volcanoes. 

 At first there was an urgent demand for news concerning the incident, 

 and interest concentrated more in the human than in the scientific side 

 of the story. Corps of photographers, reporters, journalists, geologists, 

 and geographers were hurried to the islands by enterprising publications, 

 societies, and individuals. Publishers required immediate copy, and 

 although the scientific writers demurred to hasty delivery, because there 

 had not been sufficient time for study and deduction of data, the remu- 

 neration offered was such that narratives had to be forthcoming. This 

 ravenous public desire for information was as ephemeral as the great 

 tragedy itself, for when, nearly three months later, Martinique suffered 

 another terrible holocaust the incident received but a few lines of mention. 



Among the geologists of the Dixie expedition were Professors Jaggar, 

 of Harvard ; Hovey, of the New York Museum of Natural History ; Pro- 

 fessor Russell, and the writer, representing the National Geographic 

 Society. Professor Angelo Heilprin, of the Philadelphia Academy of 

 Science, also arrived a little later. The Roj^al Society of England sent 

 out an excellent commission, composed of Messrs Flett and Anderson. 

 Shortly afterward a commission of French geologists, headed by Professor 

 Lacroix, pursued continuous investigations on the ground. Still later 

 Professor Karl Sapper, the German savant, added the value of his per- 

 sonal observations to the event. Professors Hovey and Jaggar remained 

 on the island after many of us left and obtained additional detailed data 

 concerning the volcanoes. Professor Heilprin made a second visit to 

 Pele* in August and Professor Hovey returned to the island in February, 

 1903. 



The observations of all the earlier parties were fragmentary, and the 

 acquisition of knowledge of the volcanoes has been gradual and progress- 

 ive. With the possible exception of the French commission, the studies 

 of the geologists were largely devoted to the examination of the im- 



