254 ANNUAL REPORT SMITHSONIAN INSTITUTION, 192 8 



coast line between Africa and Brazil has long vexed geologists and 

 geographers, and a friend of the writer recently remarked that it 

 must have been " made by Satan " for that very purpose. 



Wegener tells us in the opening paragraph of his book that he 

 came to this hypothesis in 1910 on noting — 



the similarity of tlie shapes of the coast lines of Brazil and Africa (Fijrure 1). 

 Not only does the great right-angled bend formed by the Brazilian coast at 

 Cape San Roque find its exact counterpart in the reentrant angle of the African 

 coast line near the Cameroous, but south of these two corresponding points 

 every projection on the Brazilian side corresponds to a similarly shaped bay 

 in the African, and, conversely, each indentation in the Brazilian coast has a 

 complementary protuberance on the African. Experiment with a compass on a 

 globe shows that their dimensions agree accurately. 



Now let us see what questions these two fitted pieces of the jig-saw 

 puzzle raise. 



According to the displacement theory, hundreds of millions of 

 years ago the South American plateau lay directly adjoining the 

 African one, but in early Cretaceous time South America began to 

 drift westward through the stiff basaltic material. Similarly, North 

 America was close to Europe, and also began to drift westward in 

 the Cretaceous, but, at least from Newfoundland and Ireland north- 

 ward they still formed, with Greenland, one connected block until the 

 end of Pliocene time. 



We have seen that South America parted company with Africa 

 in early Cretaceous time. Accepting the age of the earth as 1,500,- 

 000,000 years, this break occurred about 120,000,000 years ago. 

 During this vast time the sea waves have been continuously pound- 

 ing against Africa and Brazil and in many places rivers have been 

 bringing into the ocean great amounts of eroded material, 3'et every- 

 where the geographic shore lines are said to have remained practi- 

 cally unchanged. It apparently makes no difference to Wegener 

 how hard or how soft are the rocks of these shore lines, what are 

 their geological structures that might aid or retard land or marine 

 erosion, how often the strand lines have been elevated or depressed, 

 and how far peneplanation has gone on during each period of con- 

 tinental stability. Furthermore, sea level in itself has not been con- 

 stant, especially during the Pleistocene, when the lands were covered 

 by millions of square miles of ice made from water subtracted out 

 of the oceans. In the equatorial regions, this level fluctuated three 

 times during the Pleistocene, and during each period of ice accumu- 

 lation the sea level sank about 250 feet. Nowhere does Wegener 

 discuss these matters, yet he wants us to believe that the original 

 fracture lines have practically retained their original geogi-aphic 

 shape during the 120,000,000 3'ears. Is there a geologist anywhere 

 v>'ho will subscribe to this startling assumption? From T. 6. Bos- 



