Has the climate been growing gradually colder to the present time?
What is the evidence of a somewhat recent period of intense cold?
What recent local changes of climate are mentioned as having occurred?
SECTION VI.
State the general advantages of geological changes.
By what changes have the coal-beds and other stratified rocks become accessible?
What advantage from these elevating forces in reference to the granitic rocks?
Fig. 69.
How do these changes affect our means of knowing the structure of the earth?