CASS COUNTY. 93 



and underlies a bed of sandy clay. The Alamo lignite appears to be divided 

 into two beds, one at forty-nine feet and the second at sixty-five feet. A 

 section of the shaft is 



1. Sand and clay 26 feet. 



2. Gray clay 23 feet. 



3. Lignite 1 foot 8 inches. 



4. G-ray sand 2 feet. 



5. Hard slaty clay 9 feet. 



6. Lignite 4 feet 2 inches. 



The lower lignite bed was not cut through. 



This shaft was sunk by a company with the intention of mining the lignite 

 of the lower bed, but, owing to the difficulties encountered, the undertaking 

 had to be abandoned. The quantity of water accumulating in the shaft, to- 

 gether with the- softness of the overlying material, contributed largely to the 

 failure of the company. 



Closely allied with, and probably belonging to, the lignitic series there 

 is a black sandy clay. This clay occurs in the section shown on the A. 

 D. Duncan headright and also in a small circular valley on the D. Glaze 

 headright, about eight miles west of Linden. On the Duncan headright it 

 shows a thickness of six feet, and on the Glaze headright six or seven feet. 



While this black clay can not be utilized for the purpose of making earth- 

 enware, the small proportions of lime and iron will also militate against its 

 being of any value in the way of a glazing material. To serve this purpose 

 a clay requires to possess a great quantity of materials capable of producing 

 fusible silicates; that is, the constituents of the clay will require to be in such pro- 

 portions as will combine and fuse more readily than the clay constituting the 

 main body of the ware. At the present time the glaze used for making black 

 ware is mostly if not altogether imported from Albany, N. Y., and is usually 

 known among pottery men as "Albany slip." The following is an analysis 

 of this glaze made by Dr. Brackett, of the Arkansas Geological Survey: 



Silica 58.05 



Alumina 14.86 



Ferric oxide _ 6.76 



Lime 6.61 



Magnesia 3.08 



Potash 1.18 



Soda 0.80 



Loss on ignition 7.41 



98.75 



The fusible qualities of this clay consist of the high proportions of ferric 

 oxide, lime, magnesia, potash, and soda. 



