142 DETAILED REPORT ON ALABAMA CLAYS. 



combined water that the clay shows, for it is evident- 

 ly a low grade bauxite like the preceding one. 

 The composition is : 



Analysis of Fire Clay, Rock Run, Cherokee Co., No. 5. 



Silica 31.20 



Alumina 44.28 



Ferric oxide 1.45 



Lime 1.00 



Magnesia .20 



Ignition 22.CO 



100.73 

 Total fluxes 2.65 



This clay is evidently a mixture of clay and bauxite, 

 as can be seen from the high shrinkage and large per- 

 centage of combined water. 



No. 6. The color of this clay is yellow, and it is 

 fine grained but not hard, and shows numerous slick- 

 enside surfaces. In slaking it breaks up easily but 

 slakes completely to powder only after long immer- 

 sion in water. The clay is very lean, and requires as 

 much water as the preceding to mix it up; the tensile 

 strength is also very low being under 5 pounds. The 

 air shrinkage is 2 per cent., the total shrinkage at 

 2200 F. is 8 per cent. ; at 2250 F. it is 12 per cent. ; 

 at 2400 F. it is 13 per cent; at 3500 F. it is 15 per 

 cent. ; at 2600 F. it is 20 per cent, and the bricklet 

 was still very absorbent. 



In the Deville furnace at cone 27, the clay had burn- 

 ed dense, but still preserved its form with sharp edges 

 and showed a total shrinkage up to this point of 35 

 per cent. 



The composition of the clay is as follows : 



Analysis of Fire Clay, Rock Run, Cherokee Co., No. 6. 



Silica 34.60 



Alumina 45.80 



Ferric oxide .52 



Ignition 20.00 



100.92 

 Total fluxes .52 



