THE CIRCULAR, SQUARE, AND OCTAGONAL EARTH- 
WORKS OF OHIO, 
By Cyrus THOMAS. 
OBJECT OF THE PAPER. 
The object in view in submitting this paper is to give a summary 
of the results of a recent survey, by the Mound Exploring Division 
of the Bureau, of the more noted circular, square, and octagonal works 
of central and southern Ohio, and incidentally to call attention to some 
errors in the “Ancient Monuments” of Squier and Davis in regard to 
them. As most of the errors to be noted are based on internal evi- 
dence contained in the Ancient Monuments, reference will first be made 
to them, after which the Bureau surveys of the same works will be 
given. 
NUMBERS AND MEASUREMENTS IN *“*ANCIENT MONUMENTS.” 
Of the seventy-eight different works figured in chapters 1 and 2 of 
their memoir, relating to “Works of Defense” and ‘Sacred Inclosures,” 
which include all the groups the authors claim to have examined per- 
sonally, it appears that Squier and Davis surveyed but twenty-six, or 
one-third. The descriptions and surveys by Col. Whittlesey and Mr. 
McBride were furnished to them in manuscript, and appear in print 
for the first time in Ancient Monuments. Our re-examination has 
been limited to the still existing works surveyed by them and Col. 
Whittlesey, which contain circles, squares, or octagons. 
So far as a comparison on the ground has been made (which com- 
prises nearly all the works surveyed by them and Col. Whittlesey of 
the character mentioned, not obliterated) their figures appear, to the 
eye, generally to be correctly drawn, andin this fact lies the chief value 
of their work, as their descriptions are brief and usually void of minute 
details. 
The lack of these details, the fact that their measurements are in 
most cases givenin round numbers, and their omission to state whether 
these measurements were taken from the middle, the inside, or the out- 
