134 GEOLOGY OF OHIO. 



No. 1. Shale used by Bucyrus Brick & Terra Cotta Company, mined at Glouster, 

 Ohio, on horizon of Cambridge Limestone. Lord, Chemist. Average sample. 



No. 2. Same shale with addition of one-fourth leached drift clay, added to in- 

 crease plasticity ; same place. Lord, Chemist. Average sample. 



No. 3. Shale from Royal Brick Company, Canton, Ohio, from the horizon of the 

 Putnam Hill Limestone; Average sample. Lord, Chemist. 



No. 4. Shale from Waynesburgh Brick & Clay Manufacturing Company, from 

 the Middle Kittanning horizon. Lord. 



No. 5. Shale from the Ohio Paving Company, Columbus, Ohio, mined at Dar- 

 lington, Ohio, on Lower Kittanning horizon. Average sample. Lord, Chemist. 



No. 6. Shale and fire clay mixture, from the A. O. Jones Company, Zanesville, 

 from the Kittanning horizon. Lord, Chemist. 



No. 7. Shales and fire clays mixed from the T. B. Townsend Brick Company, 

 Zanesville. Freeport shales and Kittanning. Fire clays. Lord, Chemist. 



No. 8. Shales from Columbus Sewer Pipe Company, from Huron shale horizon. 

 Average sample. Macpherson, Chemist. 



No. 9. Bedford shale northern Ohio ; Chemist not given. 



No. 10. Same shales different sample and another chemist; name not given. 



No. 11. Shales from Royal Brick Works, Canton, Putnam Hill horizon. Kind 

 of sample not stated. Rattle & Nye, Chemists. 



No. 12. Same shales at another opening, kind of sample not stated. O. Wuth, 

 Pittsburgh, Pennsylvania, Chemist. 



No. 13. Shales from Holloway Paving Brick Company. North Industry; from 

 L. Mercer horizon. Kind of sample not stated. Stein & Schwartz, Philadelphia > 

 Chemists. 



No. 14. Average of first ten analyses. 



The three last anlyses in the table are by reputable chemists and com- 

 mand respect on that account, but the extraordinary character of the re- 

 sults, show that the samples are not indicative of the average composi- 

 tion of the shales, and the results are excluded from the averages on that 

 account. 



The analyses of the Bedford shales are given as being of interest and 

 pertinent to the subject, though, as far as is known, they have never been 

 used lor paving or sewer pipe purposes. 



This table of results shows a most unexpected regularity in the char- 

 acter of the shale clays from the various horizons of the state, and by in. 

 ference we form a new opinion of the probable character of the other 

 great shale formations now practically untouched. 

 These clays show an average composition of 

 84.78 clay and sand, 

 13.22 fluxes, 



98 00 

 with a variation in ten samples of only 4.1 per cent, in clay and sand, and 

 6.04 per cent, in fluxing ingredients. 



An examination of the oxygen ratio of the average clay shows 



Acid, 2.19: base 1. 



Alumina, 2.72: fluxes 1. 

 or nearly a bisilicate with over a quarter of its oxygen derived from 

 fluxes. This composition indicates a very ready fusibility, which is what 

 the facts brins: forth. 



