424 



SCIENCE. 



[N. S. Vol. XVII. No. 428. 



column of molten lava rose to the orifice and 

 exploded. In this place Professor Heilprin 

 apparently holds to the view that the ma- 

 terials ejected are comminuted country rock — 

 an opinion heartily endorsed by the present 

 reviewer. The crater is described as occupy- 

 ing the entire basin of the ancient ifetang See, 

 and this lay in a gorge distinct from that 

 other head-water tributary of the Eiviere 

 Blanche, known as the Riviere Claire, where 

 in 1851 a number of vents opened and ejected 

 ashes. While this is doubtless true, it is 

 probable that all these gorges are now united 

 in the present great amphitheater filled by the 

 new cone. Professor Heilprin recognizes the 

 difficulty attending all surmises as to the ex- 

 act location of the opening whence came the 

 destroying blast; but he believes it most prob- 

 able ' that the blast issued from the basal floor 

 of the basin, rather than from a constructing 

 cone.' He states that the lower discharges 

 were always more violent and paroxysmal than 

 those from the upper cone, and that they car- 

 ried the heaviest charges of ash, sometimes 

 to heights of two miles or more. In this there 

 is no suggestion of a vent low down on the 

 mountain slope, but merely the difference 

 between the base and the summit of the new 

 cone. Violent discharge from the side of the 

 cone has also been noted by Lacroix, and this 

 characteristic is a common one; the ancient 

 crater of Soufriere in St. Vincent, as described 

 in the chronicles of 1812, had a central cone 

 and lakes at the side. The present crater in 

 St. Vincent, when visited by the reviewer on 

 May 31, showed most violent activity on the 

 southeast side of the great cauldron, rather 

 than in its middle. In the center beneath the 

 boiling waters of the pool, there is probably 

 to-day a cone similar to the one on Mont 

 Pelee, representing the direct back-fall of the 

 heaviest materials ejected vertically. 



In discussing the volcanic relations of the 

 Caribbean basin. Professor Heilprin follows 

 Suess in the belief that the Caribbean Sea 

 is comparable with the Mediterranean as an, 

 area of depression, surrounded by mountain 

 ridges, the islands of the Antilles being in 

 the main merely disrupted parts of a once 

 ' continuous land area.' It is hard to follow 



him confidently when he states that the vol- 

 canic activity of these islands belongs ' to a 

 period of no great geological activity — per- 

 haps nowhere more ancient than the middle 

 tertiary.' Hill has shown clearly that in 

 miocene time there was the most notable 

 erogenic movement in tertiary Caribbean his- 

 tory, and active vulcanism dates probably from 

 the beginning of the eocene. The Suess 

 theory that the Caribbean-Gulf basins are 

 great subsiding areas which ' break, squeeze 

 and press, and as a resultant lands are folded 

 up and volcanic discharges brought to the sur- 

 face,' is simple and attractive, but in no way 

 proved. The same may be said of the phi- 

 losophy which links volcanic eruptions on one 

 side of an ocean, with earthquakes on the 

 other that chance to be contemporaneous, or 

 nearly so. It is strange that a colossal seismic 

 disturbance that would bring about correlated 

 phenomena in Guatemala, St. Vincent and 

 Martinique should have no effect whatever on 

 other vents along the same line of fissures as 

 those of these islands. It seems safer to 

 regard such large generalization with a dis- 

 trustful eye, and to keep in mind earth scale 

 when we speak of ' the outer crust or shell 

 of the globe as resting on a molten interior.' 

 The horizontal scale of the Caribbean Sea, 

 in proportion to the vertical relief of the 

 tiny volcanic blisters, is so enormous that it 

 seems safe to treat the little volcanic fissures 

 very superficially. We know nothing of the 

 earth's ' interior,' nor even of a ' shell.' All 

 that geologists know of rocks can hardly be 

 called a film, in proportion to the great un- 

 known globe within. While the author's view 

 on these points may be open to question, 

 we entirely agree with his opinion that there 

 is no evidence of any recent decrease of vol- 

 canic activity in the Caribbean region, and he 

 might well go further and question whether 

 there has been diminution since prehistoric 

 times; human time, like human measure of 

 space, is inadequate for determining such a 

 qtiestion. 



In the discussion of the phenomena, pre- 

 sumably the statement on page 272 that the 

 ' sweep of the blast could not have been less 

 than from one to two miles an hour ' is a 



