THE EARTH-BOOK. 
11 
ous fossil fishes, and lies upon a series of formations 
(^^umber 2) which comes to the surface in northern 
Illinois, southern Wisconsirr, and along the mountain 
belts. It is full of old, quaint forms of life, and con¬ 
tains much of the valuable metals. In the northern 
part of Wisconsin and in Canada we find as surface 
rocks a formation of rocks mostly granite continuing 
beneath Number 2. They seem to be the oldest; 
for thus far we have found no other strata on the 
surface anywhere that extend beneath them. It must 
be Number 1, the first chapter that wind and water 
have written. 
We see, then, that the earth-book has seven chap¬ 
ters. Each is full of interest, and has engaged the 
attention of great intellects in different parts of the 
world for a lifetime. Thus far I have traced only 
summarily their relative positions in order to give 
you an idea how the ages and periods are determined. 
I will now take up, as space will permit, the different 
chapters of the earth’s evolution. 
“ What cause 
Moved the Creator, in his holy rest 
Through all eternity, so late to build 
In Chaos; and, the work begun, how soon 
Absolved.” 
Milton. 
