330 J. D. Dana on American Geological History. 
the Infinite Creator from his works? Far from it: no more 
than in tracing the history of a plant. We but study the 
method in which Boundless Wisdom has chosen to act in crea- 
tion. For we cannot conceive that to act without plan or order 
is either a mark of divinity or wisdom. Assuredly it is far from 
the method of the God of the universe, who has filled all nature 
with harmonies; and who has exhibited his will and exalte 
purpose as much in the formation of a continent, to all its de- 
tails, as in the ordered evolution of a human being. And if 
man, from studying physical nature, begins to see only a Deity 
of physical attributes, of mere power and mathematics, he has 
but to look within at the combination of the affections with in- 
tellect, and observe the latter reaching its highest exaltation 
when the former are supreme, to discover proofs that the highest 
glory of the Creator consists in the infinitude of his love. 
My plan, laid out in view of the limited time of a single ad- 
dress, has led me to pass in silence many points that seem to 
demand attention or criticism; and also to leave unnoticed the 
s . 
There are some subjects, however, which bear on general 
geology, that should pass in brief review. 
I. The rock ions i i 
periods. 
The revolution closing the Azoic Age, the jirst we dissoes 
the 
_An epoch of some disturbance between the Lower and Upper 
Silurian is recognized on both continents. Yet it was less com- 
plete in the destruction of life on Europe than here, more species 
there surviving the catastrophe; and in this country there was 
but little displacement of the rocks. 
‘The Silurian and the Devonian Ages each closed in America 
with no greater revolutions than those minor movements which 
divided the subordinate periods in those ages. Prof. Hall ob- 
serves that they blend with one another, and the latter also 
with the Carboniferous, and that there is no proof of contem- 
oraneous catastrophes giving them like limits here and 1 
eae idee A 
were far less general than with us, and occurred along at the 
beginning and end of the Permian Period. ot 
a 
