NORTH AMERICAN ARCHAEOLOGY. 
9 
While, however, the defensive earthworks occupy hill tops, and 
other situations most easy to defend, the so-called sacred enclosures 
are generally found on “ the broad and level river bottoms, seldom 
“ occurring upon the table-lands, or where the surface of the ground 
“ is undulating or broken.” They are usually square or circular in 
form; a circle being often combined with one or two squares. “ Oc- 
“ casionally we find them isolated, but more frequently in groups. 
“ The greater number of the circles are of small size, with a nearly 
“ uniform diameter of two hundred and fifty or three hundred feet, 
“ and invariably have the ditch interior to the wall.” Some of the 
circles, however, are much larger, enclosing fifty acres or more. The 
squares or other rectangular works never have a ditch, and the earth 
of which they are composed appears to have been taken up evenly 
from the surface, or from large pits in the neighbourhood. They 
vary much in size ; five or six of them, however, are “ exact squares, 
“ each side measuring one thousand and eighty feet—a coincidence 
“ which could not possibly be accidental, and which must possess 
“ some significance.” The circles also, in spite of their great size, 
are perfectly round, so that the American Archaeologists consider 
themselves justified in concluding that the mound-builders must have 
had some standard of measurement, and some means of determining 
angles. 
The most remarkable group is that near Newark, in the Scioto 
Yalley, which covers an area of four square miles ! A plan of these 
gigantic works is given by Messrs. Squier and Davis, and another, 
from a later survey, by Mr. Wilson. They consist of an octagon, 
with an area of fifty, a square occupying twenty acres, two large 
circles occupying respectively thirty and twenty acres. Prom the 
octagon an avenue formed by parallel walls extends southwards for 
two miles and a half; there are two other avenues which are rather 
more than a mile in length, one of them connecting the octagon with 
the square. 
Besides these, there are various other embankments and small 
circles, the greater number about eighty feet in diameter, but some 
few much larger. The walls of these small circles, as well as those of 
the avenues and of the irregular portions of the works generally, are 
very slight, and for the most part about four feet in height. The 
other embankments are much more considerable; the walls of the 
large circle are even now twelve feet high with a base of fifty feet, 
and an interior ditch seven feet deep and thirty-five in width. At 
the gateway, however, they are still more imposing; the walls being 
sixteen feet high, and the ditch thirteen feet deep. The whole area 
is covered with “gigantic trees of a primitive forest;” and, say 
Messrs. Squier and Davis, “ in entering the ancient avenue for the 
“ first time, the visitor does not fail to experience a sensation of awe, 
“ such as he might feel in passing the portals of an Egyptian temple, 
“ or in gazing upon the silent ruins of Petra of the desert.” 
The city of Circleville takes its name from one of these embankments, 
