170 DETAILED REPORT ON ALABAMA CLAYS. 



In the case of the Ohio samples no physical tests have 

 been made. 



(No. 115.) 

 STONEWARE CLAY. 



J. C. BEAN, TUSCALOOSA CO, 



This is from the property of J. C. Bean, near Tusca- 

 looso, in S. 31, T. 20, R. 11. The bed of clay is 6 feet 

 thick and overlain by 4 feet of white sand. 



It is a rather finegrained dense clay, which slakes very 

 slowly. On mixing with 36 per cent, of water, it gave a 

 very plastic mass, whose air shrinkage was 11 per cent., 

 at 2200 F. the clay burned a pinkish brown and showed 

 a total shrinkage of 16 per cent., while at 2250 F. it 

 burned a grayish brown with a total shrinkage of 18 per 

 cent. Incipient fusion occurs at 2100 F., vitrification at 

 2300 F. and viscosity at cone 27 in the Deville furnace. 

 Owing to the extreme plastice nature of the clay it was 

 very hard to make briquettes which did not show evidence 

 of flaws so that the tensile strength ranged from only 90 

 to 100 pounds per square inch, which is probably low. 

 Specific gravity 2.40. 



(No. 100.) 

 .POTTERY CLAY. 



J. C. BEAN, TUCALOOSA CO. 



This is a rather fine grained clay, and at the same time 

 a dense one. It contains an appreciable quantity of or- 

 ganic matter which not only increases the plasticity but 

 also necessitates slow drying and burning of the material. 

 The addition of 31.5 per cent, of water to the clay con- 

 verts it into a very plastic mass, whose shrinkage in air 

 drying amounted to 9 per cent. In burning incipient 

 fusion occurs at 2100 F., at which point the total shrink- 



