DIFFICULTIES OF DEVELOPMENT, ETC. 67 



a mile and a half in length, part of the way cut through solid rock. 

 Artificial reservoirs for water were made within it, while at one ex- 

 tremity, on a more elevated point, a keep is constructed with its sep- 

 arate defenses and water-reservoirs. Another, called Clark's Work, 

 in the Scioto Valley, which seems to have been a fortified town, in- 

 closes an area of one hundred and twenty-seven acres, the embank- 

 ments measuring three miles in length, and containing not less than 

 three million cubic feet of earth. This area incloses numerous sacri- 

 ficial mounds and symmetrical earthworks in which many interesting 

 relics and works of art have been found. 



The second class the sacred inclosures may be compared for ex 

 tent and arrangement with Avebury or Carnak but are in some 

 respects even more remarkable. One of these, at Newark, Ohio, cov- 

 ers an area of several miles with its connected groups of circles, octa- 

 gons, squares, ellipses, and avenues, on a grand scale, and formed by 

 embankments from twenty to thirty feet in height. Other similar 

 works occur in different parts of Ohio, and by accurate survey it is 

 found not only that the circles are true, though some of them are 

 one-third of a mile in diameter, but that other figures are truly square, 

 each side being over one thousand feet long, and, what is still more 

 important, the dimensions of some of these geometrical figures in dif- 

 ferent parts of the country, and seventy miles apart, are identical. 

 Now, this proves the use, by the builders of these works, of some 

 standard measures of length, while the accuracy of the squares, cir- 

 cles, and, in a less degree, of the octagonal figures, shows a consid- 

 erable knowledge of rudimentary geometry, and some means of meas- 

 uring angles. The difficulty of drawing such figures on a large scale 

 is much greater than any one would imagine who has not tried it, and 

 the accuracy of these is far beyond what is necessary to satisfy the 

 eye. We must therefore impute to these people the wish to make 

 these figures as accurate as possible, and this wish is a greater proof 

 of habitual skill and intellectual advancement than even the ability 

 to draw such figures. If, then, we take into account this ability and 

 this love of geometric truth, and further consider the dense population 

 and civil organization implied by the construction of such extensive 

 systematic works, we must allow that these people had reached the 

 earlier stages of a civilization of which no traces existed among the 

 savage tribes who alone occupied the country when first visited by 

 Europeans. 



The animal mounds are of comparatively less importance for our 

 present purpose, as they imply a somewhat lower grade of advance- 

 ment ; but the sepulchral and sacrificial mounds exist in vast num- 

 bers, and their partial exploration has yielded a quantity of articles 

 and works of art which throw some further light on the peculiarities 

 of this mysterious people. Most of these mounds contain a large 

 concave hearth or basin of burnt clay, of perfectly symmetrical 



