PIKE COUNTY. 613 



larger portions of the original plateau have been preserved. In Sunfish, 

 Newton, and Camp Creek townships, these islands of the middle and 

 upper Waverly frequently take in several thousands of acres. But the 

 amount of denudation that has been suffered even here is strikingly 

 shown in the few summits that rise so conspicuously along the western 

 boundary of the Scioto valley in the central districts of the county. 

 Painter's Knob, near Jasper, can be taken as a representative of this 

 class of summits. It has an elevation of 633.3 feet, by the engineer's 

 level, above low water of the Scioto, 764.5 feet above low water of the 

 Ohio at Cincinnati, and 1196 5 feet above tide water. Its elevation above 

 the general level of the country around it is nearly four hundred feet. 

 In other words, the middle and upper Waverly have been carried away, 

 by aqueous agencies, from wide belts of country to a thickness of at 

 least four hundred feet 



On the east side of the Scioto the geological composition of the pla- 

 teau again changes. The Waverly beds have now been carried by the 

 easterly dip that prevails in all of this portion of the State below the 

 Carboniferous conglomerate, heavy deposits of which constitute the 

 highest surface of Jackson, Beaver, and Marion townships. In the first- 

 named township especially, this formation impresses peculiar features 

 on the country which it occupies. Its purely silicious composition ren- 

 ders it proof against all chemical agencies of the atmosphere. The bor- 

 ders of the high lands that it forms are, therefore, almost every where 

 precipitous walls of the pebble rock, the height of which depends upon 

 the thickness of the formation, generally ranging between seventy-five 

 feet and one hundred feet. The valleys are narrow, and the ridges be- 

 tween those that are contiguous project with their well-defined bound- 

 aries like the fingers from the hand. 



The highest land of the county, as has already been intimated, is found 

 on its western border. The hills along the Sqioto are absolutely higher 

 above the base from which they rise, but the base itself is depressed more 

 than one hundred feet below the lowest land on the western boundary. 

 The elevation of a few points in the county are appended. Those marked 

 with a star are taken from the survey of the .abandoned railroad line 

 from Hillsborough eastward to Jackson. The remainder have been de- 

 termined by the level during the progress of the Geological Survey in 

 the county. In the railroad survey, low water at Cincinnati is counted 

 four hundred and forty feet above tide water, which is eight feet in ex- 

 cess of the figures given by Humphrey and Abbott. The elevations can 

 accordingly be reduced by this amount. The first station named lies just 



