174 SPARKS FROM A GEOLOGIST'S HAMMER. 



Nevertheless, it is well ascertained that the American 

 Indian dwelt in the Mississippi valley before the disap- 

 pearance of the Mammoth and Mastodon; and it is highly 

 probable that he saw Lake Michigan spreading over Peo- 

 ria and Marshall and Whiteside counties, and that he 

 paddled his canoe over the regions where these mysterious 

 relics of copper, iron and clay have been discovered. We 

 thus apprehend that the present oi-der of things connects 

 itself by an intelligible continuity with a former set of 

 conditions identified with the origin of a great geological 

 formation; and we feel that we command a unit of meas- 

 ure for a genuine geological aeon. 



Thus, when we look attentively upon the phenomena 

 occurring in the presence of our species, we find ourselves 

 living in the midst of geological history. Grand geolog- 

 ical events no longer recede into the infinite past. Though 

 earlier events reach back over ages unconiputed, the grand 

 revolutions which have made the surface what it is are 

 brought down within our grasp. We feel that we have 

 a hold upon geologic time. We can compass the requi- 

 sites of stupendous events that transform continents. We 

 feel relief in emerging from the mysteries of the unfath- 

 omable past, and setting our feet upon geologic intervals 

 which reveal their limits and their bounds. Man rises 

 to a higher altitude. He grasps a larger thought; he 

 feels his way closer to the infinite purposes; he is con- 

 scious of it; and exults anew in his intelligent existence. 



