314 GEOLOGY. 



evolving man at last at the summit of the series, the dif- 

 ference between him and the highest of other animals 

 being only in degree. But there is no such regularity 

 of gradation, and man is not merely the highest in grade 

 of all animals, but he differs from them in the possession 

 of mental attributes, that ally him with the Infinite, and 

 force upon us the conviction that the earth was made for 

 him, and that he alone is the end of its creation. 



CHAPTER XX. 



CONCLUDING OBSERVATIONS. 



425. Geology and Astronomy Compared. In Astrono- 

 my we take into consideration systems of planets which 

 are at immense distances from each other, but in Geol- 

 ogy our view is confined to a single planet, and that a 

 comparatively small one. In the study of Astronomy 

 we have only the vast and the grand before us, and 

 there is nothing small, or even moderate in size, much 

 less minute ; but in Geology we have a combination of 

 the vast and the small, so that the study has more of 

 the elements of interest in it than Astronomy presents. 

 While conceptions of grandeur are sufficiently awaken- 

 ed by some of the extended movements of continent- 

 making, much of the subject lies directly under our feet, 

 and invites the most familiar examination. The interest 

 is enhanced when we see that even operations so minute 

 as to call for the microscope in their investigation have 

 been concerned in laying down strata of immense extent 

 and thickness, in the building up of continents, and that 

 these operations are in some degree still going on. Be- 

 sides, the fact that it is our earth that we examine in 

 its vast stony leaves that all those multiform processes 

 which have occupied long ages were constructing a hab- 

 itation for us, gives to the study an interest which does 

 not attach to the study of other planets. 



