EVOLUTION OF THE EARTH'S FEATURES. 745 



extent defined in pre-Silurian time (p. 160), the course of the Archaean, 

 from the Great Lakes to Labrador, being that of the Appalachians, 

 and various ridges in the Rocky Mountains foreshadowings of this 

 great chain, and so on in many lines over the continental surface ; 

 and thus its adult characteristics were as plainly manifested in its be- 

 ginnings as are those of a vertebrate in a half developed embryo. 



1 1. The prevalent courses of coast-lines, mountain-chains, and groups 

 of islands over the globe are two, — one from about northeast-by-east 

 to southwest-by-west, and the other from about northwest-by-north to 

 southeast-by-south (p. 29). 



12. In the courses of the earth's outlines, while there are two prev- 

 alent trends, there are very commonly curves : in some cases a gradual 

 curve, as from E. N. E. to N. N. E., as in the great central chain of 

 the Pacific ; or from N. W. to W., and then to N. N. W., as in the 

 line from New Zealand to Malacca (p. 33) ; in others, a series of sev- 

 eral curves, as in the island-ranges off the Asiatic coast (p. 35), and 

 also on the east coast of North America. 



13. The earth toward or about the equatorial regions is belted with 

 oceanic waters separating its northern and southern continents, pass- 

 ing through the East Indies, Red Sea, Mediterranean, and West In- 

 dies ; and this region is remarkable for its volcanoes (p. 703). 



The preceding are some of the characteristics of the globe, which 

 exhibit the system that pervades its physiognomy, and illustrate the 

 manner in which this system was educed. They correspond in com- 

 prehensiveness and grandeur with the agency appealed to for their ex- 

 planation. 



2. Development of the Earth's System or Features. 



1. Action of the Pressure against the Continental Boi-ders. — The 

 positions of the great mountain-chains along the borders of the con- 

 tinents, and of uplifts, fractures, plications, volcanoes, metamorphism, 

 chiefly on the seawai'd slope of the chains, prove that, while the force 

 from contraction was a universal force over the sphere, the lateral 

 pressure was vastly more effective in a direction from the ocean than 

 in the reverse direction. Now this landward action of the force is a 

 necessary consequence of the fact that the crust over the oceanic areas 

 was and is depressed below the level of the continental, so that the 

 lateral pressure from its direction would have had the advantage of 

 leverage beneath the Continental crust, or, rather, would have acted 

 obliquely upward against it. 



2. Pressure against the Continental Borders greatest on the sides of 

 the largest oceans. — The fact that the largest and loftiest mountain 

 chains, greatest volcanoes, and other results of uplifting and disruptive 



