HARRISON COUNTY. 145 



also be found in the eastern portion of the county, but only in a limited 

 extent. 



Most clays suitable for the manufacture of bricks will make drain tiling. 

 Care must be taken, however, to see that the clay or earth be not too sandy. 

 Drain tiles made from sandy clay are, as a general thing, too weak to stand 

 much handling. 



The necessity for a good quality of drain tiles in Harrison County can 

 hardly be over estimated. Extensive areas throughout the county, especially 

 in the lower lying lands, would be materially benefited by a thorough system 

 of drainage. Lands at present lying idle and subject to overflow could be 

 brought into cultivation, and those at present cultivated would have their 

 agricultural capabilities greatly increased. The market for such articles need 

 not be limited to Harrison County alone, but might be found in other coun- 

 ties throughout East Texas, as well as in Western Louisiana. 



Good clays for the manufacture of drain tiling are to be found almost as 

 extensively distributed as the brick earths throughout the county. Great 

 quantities can be procured in the neighborhood of Marshall. Both on the 

 Marshall and Longview and the Marshall and Gilmer roads, within a mile of 

 the town, a clay suitable for tiling is seen in almost every cutting. This clay 

 averages from two to four feet in thickness, and is generally overlaid by a 

 brown ferruginous sand. 



The quality of this clay will be materially improved by winter tempering — 

 that is, by digging the clay in the fall or early winter and allowing it to un- 

 dergo the action of the rain and frost during the winter, spading it over 

 occasionally to bring the whole of the material under the influence of the 

 weather. By this means the clay will be mellowed and the summer's supply 

 can be procured and tempered at a less cost than it can be obtained in any 

 other manner. The brick earths of Harrison County will also be improved 

 by such a course. 



2. FIRE CLAYS. 



A good fire clay is one which will for the longest period satisfactorily resist 

 heat of the highest temperature, and to do this the clay must be free from any 

 ingredient which will combine with any of the other materials and form a 

 flux when exposed to a high degree of temperature. For this reason a clay 

 intended for the manufacture of fire bricks or any article intended for resist- 

 ing heat should be as free as possible from magnesia, lime, iron, and alkalies. 



Clays, as found in the pit or natural state, rarely contain all the necessary 

 conditions to fit them for the manufacture of first class fire bricks. They 

 have to be mixed with some material which will allow for the expansion and 

 contraction incident to an excessive heat and cooling, and at the same time 

 hold both of these conditions in check. For this purpose burned clay of the 



