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 !•<"> 



Magnesia -20 



Ignition 22.80 



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 liard, 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° P. 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 dfense, but sftill 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, Bock Run, Cherokee Co., No. 6. 



Silica 34.60 



Alumina 45.80 



Ferric oxide .52 



Ignition 20.00 



100.92 

 , Total fluxes 52 



