r, often of a small size.
Where they occur separately they either have no gateway, or but one.
Sometimes the circles are of very large size, surrounding many acres.
Sometimes, though not very often, a ditch was also dug inside the
embankment. This last circumstance is by many regarded as a strong proof
that the primary object of these circles was not for defense.<59> But an
inclosure of this kind, even with the ditch on the inside, if surmounted
by a row of pickets or palisades, would prove a strong position against
Indian foes armed with bow and arrow. The Mandans constructed defenses
of this kind around their villages.<60> As to the original height of the
walls, in the majority of cases it was not very great, generally from
three to seven feet.

It is estimated that in Ohio alone there are fifteen hundred inclosures,
but a large number of them have nothing especially worthy of mention.
Some, however, are on such a large scale that they call from all
more than a passing glance. In contemplating them, we feel ourselves
confronted by a mystery that we can not explain. The ruins of the old
world excite in us the liveliest feeling of interest, but we know their
object, their builders, and their probable antiquity. The mazy ruins at
Newark, and other places in Ohio, also fill the mind with astonishment,
but in this case we are not certain of their antiquity, their builders
are unknown, and we can not conjecture with any degree of certainty as
to their use. Before so many uncertainties imagination runs riot, and
we are inclined to picture to ourselves a scene of barbaric power and
magnificence.

Illustration of High Bank Works.-------------------

One beautiful specimen of this work is found in this cut. It occurs on
the right bank of the Scioto river, five miles below Chillicothe. Here
we notice a combination of the octagon and the circle. The areas of each
are marked. The octagon is nine hundred and fifty feet in diameter and
nearly regular in shape. In 1846 its walls were eleven or twelve feet
high, by about fifty feet base. It will be noticed that there is a gate
at or near each angle of the octagon except one, and in front of that
angle was a pit, from which some of the earth to form the walls was
taken. Facing each gateway a mound was placed, as if to guard the
entrance.

The circle connected with the octagon is perfect in shape, and is ten
hundred and fifty feet in diameter. Its walls were only about half the