924 GEOLOGY OP OHIO. 



The result is plain to be seen. The Baird Ore of Perry county is the 

 Red Ore of Union Furnace and the Limestone Ore of Hope Furnace and 

 southward. The Gray Limestone which is thin and uncertain in Perry 

 county increases in volume in Hocking county, and is found steady and 

 well developed in Vinton county. It gains this steadiness, indeed, in 

 Washington township, Hocking county, ten miles west of Nelsonville. 



The Nelsonville Coal instead of uniierlying the Gray Limestone, ranges 

 from thirty five to forty-five feet above it in Perry, Hocking, and Vinton 

 counties. This interval is observed until Bloomfield township, Jackson 

 county is reached, where an increase of ten feet in the interval is made, 

 the coal at Keystone Furnace being fifty-five feet above the limestone 

 and being here known by its southern name, viz., the Sheridan seam. 

 In the next six miles a further gain of ten feet occurs, and from that 

 point to the Ohio River, a very reliable average of sixty-five feet is 

 maintained. The country between Zaleski and Keystone Furnace has 

 been repeatedly traversed in this interest, and hundreds of sections have 

 been measured. No obscurity or doubt remains as to the general order. 



The usual interval between the Gray Limestone and the Sheridan Coal 

 in the southern counties has been shown to be sixty-five feet. Prof. 

 Andrews traced the seam northwards until the interval was reduced to 

 fifty five feet. In the Report of Progress for 1S70, page 179, he gives a 

 section near Keystone Furnace in which he notes the fact that a coal 

 which"is doubtless the the Sheridan seam, ""is nearer thelimestone than 

 usual." 



In Volume I, Geology, page 9-33, he quotes the section referred to above 

 and adds the following sentence, viz , "If the coal given in the above 

 section is tjie Sheridan coal, there was probably a mistake in the meas- 

 urement of tne space between it and the limestone." There is no 

 mistake, however, in the identification or the measurement. The coal is 

 the Sheridan coal and the measure is fifty-five feet. 



On the other hand, the Mineral City feam (Nelsonville) has been fol- 

 lowed southward from Zaleski until at Keystone Furnace it is found to be 

 fifty five feet above the limestone. There is no room for doubt or question 

 as to this fact, that the upper coal at Zdeski is the coal fifty five feet 

 above the Gray Limestone at Keystone. The wholeserieshasbeen followed 

 without a break from the first point to the last. The fire clay parting 

 by which No. VI is characterized through all this region, makes its iden- 

 tification easy and certain. A few of the intervals between the limestone 

 and the coal in this district will be given here. 



In Section twenty-two and twenty-five. Elk township, the intervals 

 are respectively foitytwo and forty feet. The cojI is here know as the 

 Cdrbondale seam. In Section twenty-five, Madison township (Vinton 



