Page:History of Iowa From the Earliest Times to the Beginning of the Twentieth Century Volume 1.djvu/35

 ATURE'S supreme laws of never ending change from one degree of development to another, seem to pervade the universe. Man in all ages has been slowly reading these immutable statutes, unwritten, and only to be known through careful observation and patient investigation.

A little gained by one generation handed down to another, since the first appearance of man upon the earth, has made the sum of human knowledge. For how many ages on some other far off planet human intellect has been slowly pursuing the same great study we have no means of knowing.

Here the astronomer has discovered the existence of other worlds, has carefully computed their size, has measured their distance from the earth and each other, has observed their motion, their satellites, and learned some of the laws which govern them. He has even constructed a plausible theory as to how these planets were formed from the original elements.

As to the comparative antiquity of the eastern and western continents of our own earth, recent investigation brings evidence to reverse the old belief that Asia and Africa were earlier formations than America. Agassiz says: