HENDERSON COUNTY. 1^7 



2. REFRACTORY CLAYS. 



The clays found in beds Nos. 1, 2, 3, and 4 are all suitable for the manu- 

 facture of refractory clay goods, such as fire bricks, furnace and cupola lin- 

 ings, fire backs for grates, etc. The clay obtained from Bed No. 4 is utilized 

 by the Texas Fire Brick and Tile Company to make all the above classes of 

 goods. The furnace linings manufactured by this company are used in the 

 iron furnace at the State Penitentiary Iron Works at Rusk, and are highly 

 commended by the superintendent of that institution. Cupola linings made 

 by the same company are also used in the Kelly Plow Company's works at 

 Longview with very satisfactory results. Large quantities of fire bricks 

 are also shipped to Dallas, Fort Worth, and other places, with satisfactory 

 results. 



Bricks made from this clay burn hard and have a chalky white or creamy 

 white color, according to their position in the kiln. When freshly burned 

 these bricks weigh about six pounds, and their power to absorb moisture is 

 about 0.6 per cent of their weight. 



In the manufacture of these fire clay goods nothing but the clay itself is 

 used. Dried lumps of clay are placed in the kiln and subjected to the same 

 amount of firing as necessary to burn the brick. This material is afterwards 

 withdrawn, ground, and mixed with the raw clay in the proportion of about 

 thirty per cent of this calcined clay or "chamotte" to seventy per cent of the 

 raw material. 



An analysis of this clay dried at 115° C, made in the laboratory of the 

 Survey, shows this clay to have the following composition: 



Silica 68 . 55 per cent. 



Alumina 26.00 per cent. 



Ferric oxide Trace. 



Potash Trace. 



Soda Trace. 



Lime Trace. 



Magnesia 0.11 per cent. 



Water and loss on ignition 6 . 00 per cent. 



100.66 



Sand * ... 4 . 20 per cent. 



Specific gravity 2.18 



3. POTTERY CLAYS. 



No thoroughly first class reliable pottery clay has been yet found in the 

 vicinity of Athens. Mr. M K. Miller has been using a clay obtained from 

 beds Nos. 1 and 2 with only partial success. The chief difficulty with these 

 clays is their non-vitrifiable qualities. In burning the ware it is found to 

 have a tendency to form too open a body in the time necessary to burn, and 



