A GRASP OF GEOLOGIC TIME. 



~j TOW shall the mind obtain relief from the oppressive 

 -* *- idea of eternity which confronts it on every page of 

 geologic history? 



We seize upon a thread of relations, and follow it back 

 through the whirl of terrestrial revolutions till the head 

 swims and the vision grows dim, and the symbols of dura- 

 tion cease to excite any adequate emotions, as when words 

 of eloquence fall upon ears of lead. We lift the veil which 

 conceals the future, and cast our glances down the vistas 

 of coming time; but again our thought is paralyzed, and we 

 sink into the depths of eternity as stupidly as the reptile 

 withering in his rocky crevice. 



Oh, for an expanse of thought that shall permit us to 

 seize upon the years of God! This world of ours, we have 

 been told, instead of being the result of creative energy 

 put forth six thousand years ago, is the product of revolu- 

 tions that have exhausted millions of years in their con- 

 summation. The twenty or thirty populations which have 

 passed like shadows over the surface of our planet, have 

 each had a duration at least equal to that of the existing 

 population, whose beginning stretches back into the fogs 

 of mystery and myth. When imagination has wandered 

 back to the beginning of this succession of life, it finds 

 itself at the conclusion of an older history, during which 

 the powers of fire and water were struggling with each 

 other for supremacy upon the globe. Still back of this 



