704 GEOLOGY OF OHIO. 



constantly varying, and can be determined only by careful observation 

 in each locality j and that any general statements that suggest the in- 

 ference that there is a uniform dip in any particular direction, are cal- 

 culated to mislead. In the mine at Haydenville, where now worked, the 

 dip is one foot in thirty-five, or over 150 feet per mile: and observation 

 shows that the local dip may be in any direction, and that it constantly 

 varies in amount within very wide limits. Observations and calcula- 

 tions made on widely separated data at different points will show the 

 general dip of the rock strata. After all, these irregularities and undu- 

 lations are eliminated or disregarded, but they are calculated to mislead 

 the practical miners, unless supplemented by minute and detailed work 

 in each locality, requiring more work than can ordinarily be given to a 

 State survey. 



The relation of the seam to the other mineral deposits is illustrated in 

 the section here given ; 



