The geysers and hot springs of the Yellowstone are another proof of recent volcanic activity.

History in its broadest aspect is a record of man's migrations from one environment to another.

As a matter of fact, an ordinary desert supports a much greater variety of plants than does either a forest or a prairie.

We are learning, too, that the love of beauty is one of Nature's greatest healers.

America forms the longest and straightest bone in the earth's skeleton.

Curiously enough man's body and his mind appear to differ in their climatic adaptations.