262 JESSE E. HYDE 



within a few feet along its length. Just below Denver in Pike 

 County, two widely variant sets of ripples were observed on 

 adjacent planes less than an inch apart, one trending N. 28 01 

 W., the other N. 55 W. Such an extreme difference is unusual, 

 but differences of six or eight degrees between adjacent planes 

 can be found without effort. The greatest range noted at any 

 locality is 43 , in the Berea grit below Denver in Pike County. 

 The widest extremes found in the area from Chillicothe southward 

 are N. 22 W., and N. 78 W., a range of 56 . The latter has been 

 recorded several times, especially in the southern part of the area, 

 but the former is an unusual direction. It was found on one plane 

 in the Berea north of Clifford, Scioto County, associated with a 

 number on which N. 6o° W. was markedly dominant. In the 

 central Ohio outcrops the extremes are N. o° W. (on three super- 

 imposed planes at Sunbury) and N. 7 8° W. at Gahanna. This is 

 the absolute range for the whole region, 69°. 



Most of the ripple directions noted in the course of the present 

 work have been drawn in on the accompanying map. (Fig. 3.) 

 At some points where a number of directions have been noted, 

 not all are plotted, but in every case where more than one direc- 

 tion has been found, the extremes have been drawn in. On the 

 other hand, at many localities where the ripples persistently 

 trend in one direction, only one observation is plotted, and at 

 almost all points where considerable variation is indicated some 

 one direction lying between the extremes is certain to be dominant, 

 although not so indicated. Thus the map is really a map showing 

 extremes of ripple direction, not only areally but vertically. If 

 the directions were drawn in, in the order of their persistency, 

 the amount of variation which exists would largely be obscured, 

 and the unity of the direction would be much more impressively 

 set forth. As it stands, however, it is sufficient to indicate clearly 

 that some factor must have controlled the ripple direction in cen- 

 tral and southern Ohio during the time when the upper part of the 

 Bedford and Berea were accumulating. 



The ripples are entirely (so far as observed) of the oscillation 



1 Observations are all compass readings. The magnetic declination is one degree 

 or less west of the true north (determined in 1906). 



