1 84 GEOLOGY. 



was not straight, but bent upward either way, forming 

 an elbow, and shaped much like Fig. 100. If you corn- 



rig. 100. 



pare thi* with the shape of North America as a whole, 

 you will see. why this beginning of the continent had this 

 shape, as it was completed afterward by additions. The 

 elbow extends downward, as the lower part of the com- 

 plete continent does, and the larger limb of the island 

 corresponds with the more extended side of the conti- 

 nent. Some few other comparatively small azoic areas 

 are found in North America, one of which is in Missouri, 

 and includes the noted Iron Mountains. All else was sea 

 in that quarter to the end of the Azoic age. Agassiz says 

 of the long island which was the beginning of the North 

 American continent, "We may still walk along its ridge, 

 and know that we tread upon the ancient granite that 

 first divided the waters into a northern and southern 

 ocean ; and, if our imaginations will carry us so far, we 

 may look down toward its base, and fancy how the sea 

 washed against this earliest shore of a lifeless world." 



Europe was quite in contrast with America in this age. 

 There was no one great island, but several of considera- 

 ble size, and some small ones were scattered about in that 

 part of the vast azoic ocean. There was no so obviously 

 marked beginning of a continent as in the case of North 



