136 DETAILED REPORT ON ALABAMA CLAYS. 



Analysis of flre clay, Peaceburg. Calhoun Co. (No. 191.) 



Silica 51.90 



Alumina 35.00 



Ferric oxide 99 



Lime 23 



Magnesia 10 



Alkalies 55 



Ignition 11.30 



99.87 

 Total f'uxes 1.87 



The low plasticity of this clay would probably inter- 

 fere with its being used alone, but owing to its re- 

 fractory nature and the light color developed in burn- 

 ing it could no doubt find use as an ingredient of 

 other clay mixtures. 



(No. 127 of Mr. Stevens.) 

 FIKE CLAY. 



FROM OXANNA, CALHOUN COUNTY. . 



This is a coarse and sandy clay, which mixes up to 

 a lean mass with only 16 per cent, of water. The 

 tensile strength is very low, being on the average of 

 9 to 10 pounds per square inch, and the air shrinkage 

 is 2 per cent. 



The following is the behavior of the clay at suc- 

 cessively higher temperatures. 



At 2200 F. the color was grey white. 



At 2250 F. shrinkage 3 per cent., color buff. 



At 230CT F. shrinkage and color same. 



At 2400 F. shrinkage 3 per cent., color buff, show- 

 ing specks of ferric oxide. 



At 2500 F. the shrinkage was only 2 per cent, hav- 

 ing undergone a slight swelling owing to the very 

 high quartz percentage. Incipient fusion "had not 



