ditches, &c., indicating considerable acquaintance with military
science. At Newark, Ohio, a fortification exists which covers an
area of more than two miles square, and has over two miles of
embankment from two to twenty feet high.

Mounds, seemingly constructed as great altars for religious
purposes or as monuments, are also numerous. One, opposite St.
Louis, covers eight acres of ground, and is ninety feet high. There
are said to be 10,000 of these mounds in Ohio alone.

[Illustration: THE SERPENT MOUND.]

A peculiar kind of earthwork has the outline of gigantic men or
animals. An embankment in Adams County, Ohio, represents very
accurately a serpent 1000 feet long. Its body winds with graceful
curves, and in its wide-extended jaws lies a figure which the
animal seems about to swallow. In Mexico and Peru, still more
wonderful remains have been discovered. They consist not alone of
defensive works, altars, and monuments, but of idols, ruined
temples, aqueducts, bridges, and paved roads.

[Illustration: MOUNDS NEAR LITTLE ROCK, ARKANSAS.]

THE MOUND BUILDERS is the name given to the people who erected the
mounds of North America. They seem to have emigrated to Central
America, and there to have developed a high civilization. They
built cities, wove cotton, worked in gold, silver, and copper,
labored in the fields, and had regular governments.

THE INDIANS who were found on this continent east of the