632 GEOLOGY OF OHIO. 



failures. The quality of the lime has been impaired in the process. But 

 as lime is manufactured elsewhere, with coal for fuel, so it must come to 

 be here. One apparently successful experiment deserves mention: The 

 lime used in the plastering of the new Insane Asylvm was burned with 

 coal. The stone was broken quite small, and the coal was distributed 

 quite evenly throughout the kiln. A good deal of waste occurred, but it is 

 said that the cost of lime was less than half that burned with wood. 



The kilns in use are of various sorts, but the parties burning lime, in 

 the larger way, make use of some sort of draw-kiln. 



The largest manufacture is that of Stitt, Price & Co. They make use 

 of two kilns of Page's patent, one of them capable of making three hun- 

 dred and fifty bushels, and the other four hundred bushels per day, with 

 a daily yield of seven hundred bushels for eight months in the year. 

 They have several kilns of the old sort ; also mainly used for the winter 

 supply. One cord of wood is expected to burn sixty-six bushels of lime, 

 a result which reaches the average of the best kilns of the State. 



3. Huron shale. — The next element in the geological scale of the county 

 is the Huron shale — the Ohio black slate — of the older State geologists. 

 It occupies a much larger area than any other formation in the county, 

 and has affected the physical geography much more. It is easily eroded, 

 and, consequently, the valleys that have been wrought in it, are broad, 

 the water-sheds being reached by long and gradual slopes. It makes an 

 important contribution to the soils of the county, and impresses its own 

 character upoa considerable areas, notwithstanding the fact that this 

 whole region is included in the Drift-covered territory of the State. 



So great is the uniformity of material and arrangement in the forma- 

 tion, that it has not yet been found possible to establish divisions in it 

 that can be followed from point to point, aside from one well-marked 

 band at the bottom, and another at the top of the series. As there are 

 no vertical sections that hold more than fifty or sixty feet, it has, there- 

 fore, been impossible to determine the thickness of the shale in Franklin 

 county. It is probably not far from three hundred feet. In Ross county, 

 the heaviest sect on yet measured in the State occurs. The shale is there 

 three hundred and thirty-one feet thick. In Highland county, an in- 

 cluded section measures but two hundred and fifty feet. There is little 

 doubt, however, that careful enough study will reveal marks in the shale 

 that will allow us to secure measurements here also. 



At the base of tha series, in this county, and also in Delaware county, 

 there are thirty feet of blue shales, with calcareous bands running 

 through them, about the assignment of which, question may be raised. 

 They are included here with the Huron shale, although they are sepa- 



