CHANGES IN THE STRATIFIED ROCKS 287 
done slowly 
enough. Under 
these conditions, 
rocks are actu- 
ally made _ to 
fold by a slow 
stress, constantly 
and irresistibly 
applied. In 
thinking of the 
Fic. 166. 
Section through an anticline (A) and a syncline (S). 
behavior of rocks so situated, we must dismiss our 
conception of their action as we see it at the surface. 
Photograph of a symmetrical anticline. 
Fic. 167. 
Here, there is noth- 
ing to prevent their 
breaking as brittle 
bodies do; but deep 
in the earth, the 
pressure makes 
actual breaking less 
easy than bending, 
which to be sure 
may be accompanied 
by minute fractures. 
Faulting of Rocks. 
— Nature of the 
Fault. When the 
strata are subjected 
