SHELBY COUNTY. 245 



SOILS. 



The top soil on the ridges is sandy from the leaching action of rain water. 

 The soil on the sides of the ridges is sand mixed with a greater proportion of 

 clay. On the rolling uplands the soil is mainly red ferruginated sandy clay. 

 In the bottoms the soil is a mixture of the others from transportation, form- 

 ing the fertile sandy loam of the valleys. 



The principal products are cotton, corn, sweet potatoes, and sugar cane. 



CLAYS. 



On the rolling uplands are often seen beds of red and gray mottled clay 

 four to six feet thick, overlaid by thin sandy soil and underlaid by gray sandy 

 clay two to ten feet thick, and under this a parting of sand underlaid by blu- 

 ish clay. The red and gray mottled clay is now used in the raw state for the 

 manufacture of brick, but in this condition it usually contains pebbles and 

 iron gravel which produce ugly spots and a different rate of expansion and 

 contraction, resulting in cracks. These troubles can be partially remedied by 

 the weathering of the clay during the winter, by drying and screening before 

 dumping into the pug mill, or by washing the clay and using only "the lighter 

 material from mechanical suspension and subsequent sedimentation. The 

 lower hardpan gray clay, by weathering, screening, and thorough working in 

 the pug mill, will make a strong, compact, semi-vitrified brick, admirably 

 adapted for lining of cisterns, street and sidewalk paving in cities, etc. By 

 washing and taking the lighter parts from mechanical suspension and sedi- 

 mentation it becomes suitable for yellow pottery and jug ware. 



At the brickyard of Mr. J. J. Gibson, one mile south of Teneha, on Hous- 

 ton East and West Texas Railway, was observed the following section from 

 the excavation made for brick material: 



1. Surface soil 1 foot. 



2. Yellow sand 2 feet. 



?>. Sandy clay, somewhat ferruginated 3 feet. 



4. Mottled red and gray clay to bottom of cut. 



Here the bricks were made from the raw clay and used for local building. 

 They are also shipped in carload lots to Houston The selected bricks are of 

 a fair quality, but there is considerable loss from warping, shrinking, and 

 cracking, etc., in burning. A great improvement in quality could be made by 

 some attention to the remedies given above. Burning in clamps or properly 

 constructed permanent kilns would insure a more evenly distributed heat and 

 a more uniform product, with less loss from warping, cementing, and crack- 

 ing. 



Near the brick kiln, south of Teneha, was observed some local change in 



