286 R. T. HILL — PEI.E AND THE WINDWARD ARCHIPELAGO 



Breaking away from the old traditions, this eminent leader of geolog- 

 ical thought during the past year has boldly advocated that the sources 

 of the waters of hot springs and volcanoes are internal and not superfi- 

 cial, and that the waters of these are distinct contributions from the 

 earth's interior to its exterior. He says : * 



"The steam of the volcano cannot be derived from surface infiltration ; for, if 

 it is, whence the carbonic acid ? Both must come from the deeper regions of the 

 earth ; they are the outward sign of the process of giving off gases which began 

 when the earth first solidified, and which, today, although restricted to certain 

 points and lines, has not yet come to a final end. It is in this manner that the 

 oceans and the whole surface hydrosphere have been separated from the solid 

 crust. Volcanoes are not fed by infiltration of the sea, but the waters of the sea 

 are increased by every eruption." 



THEORY OF LINEAR ARRANGEMENT ALONG FISSURE LINES 



Another position of the crustal theorists has been the assertions as to 

 the linear arrangement of volcanoes along certain great lines of imagi- 

 nary fissures in proximity to the sea, the actual known occurrence of 

 some volcanoes along fissures, and the presumption that the volcanoes 

 could not have within themselves the power to reach the surface with- 

 out the preexistence of these fissures through which the water was let in- 



It is now found that even the data on which these deductions are based 

 are not conclusive. Volcanoes do and have occurred both on the land 

 far away from the sea and in the sea far away from the land. So far as 

 the occurrence of volcanoes adjacent to the ocean margin is concerned, it 

 may justly be argued that this arrangement is in part the natural sequence 

 of occurrence along lines of least resistance and partially due to the fact 

 that these marginal land volcanoes are merely the fringe of the greater 

 area of marine volcanoes concealed by the ocean. Indeed, increasing 

 evidence is accumulating that the greater number of volcanoes, past and 

 present, are marine and not accompaniments of the land areas, but 

 really makers of the land areas, the continental interiors representing 

 areas where in times past the crust has already been so thickened by vol- 

 canic extrusions as to prevent egress of volcanic gases in those localities.f 



While admitting that volcanic protrusions naturally may follow pre- 

 existing lines of weakness, such as faults and fissures, the Assuring also 

 usually follows the volcano. Instances are even found in the San Fran- 

 cisco and Mount Taylor regions of volcanoes far distant from oceanic 

 waters without a trace of preexisting fissures where the magma has 

 forced itself up through thousands of feet of sedimentaries. 



♦Professor Eduard Suess, Royal Geographical Journal, vol. xx, November, 1902, p. 520. 



fin this connection see the excellent chapter on submarine volcanoes in the new edition of 

 Geikie, vol. i, pp. 332-342, and his proof of the conclusion that " volcanic activity is displayed over 

 a wider region of the ocean's floor than on the surface of the land and on a more gigantic scale." 



