452 EMERSON— RECURRENT TETRAHEDRAL DEFORMATIONS. 



mass has made the only lag, the antipodal largest depressed area has 

 made the only advance. This lessens by one third the amount of 

 torsional movement heretofore assumed in the hypothesis and locates 

 it differently. 



Africa is thus the torpid center of the earth in this sense and not 

 in the more adventurous dream of Sacco,* that it is the inert center 

 from which the continents have drifted away in great floes as a 

 recoil when the Moon was torn from the bed of the Pacific, an event 

 probably never seen by any "glimpse through the corridors of time." 



I will not suppress the fanciful suggestion that if Angara land — 

 the Asian nucleus, or Manchurian shield — was formed (with Aus- 

 tralia as its southern apex) and then drifted westward, in a later 

 deformation Angara land in its new position may have grown south- 

 ward, producing the triangular peninsula of India, which is a dwarf 

 Africa, in shape a true south apex of a tetrahedral coign. 



The reviewer has elsewhere suggested that the westward move- 

 ment of these old lands, to wit, Asia, and in lesser degree North 

 America, may have been not wholly a slipping on some deep plastic 

 layer but rather in part an advance by the crumbling down of 

 eastern parts of these shields and upfolding of western parts. 



This may explain why Angara land lies on the eastern part of 

 Asia and the Canadian shield on the eastern part of America and 

 connect with the disappearance of an old land east of our Atlantic 

 coast-line. This westward advance of the Asiatic mass may explain 

 the great westward faulting around Angara land, especially along 

 its western border. 



An inspection of the map shows broad bands of land submerged 

 slightly, which extend on curved lines southeasterly from the three 

 south apices to the Antarctic continent. This suggests a westward 

 torsion of the three coigns as wholes on the Antarctic continent in- 

 dependent of the differential movements of the parts among them- 

 selves, but dependent on their varying size and distance from the 

 space. As favored by Reyer and Suess the abnormal elevation of 

 Angara Land might furnish a low slope down which a superficial 

 layer could slide, the shear being lessened by internal heat or the 

 moisture of strata newly risen from the sea, and aided by tidal 



* " Les Lois fondamentales de I'orogcnie de la Terre." 



