MARION COUNTY. 109 



small creeks for over a mile. A section of the cutting on this road, near 

 Mr. W. C. Hill's nursery, gives the following: 



1. Brown and yellow brick earth 6 feet. 



2. Thin layer of bluish gray sandy clay • 1 foot. 



3. Light blue clay, having a slightly pinkish shade 2 feet. 



On the Jefferson and Daingerfield road this clay deposit is also seen ex- 

 posed in many cuttings along the road. The best exposure is that at the 

 south side of W. C. Hill's farm. Here the clay is somewhat sandy in the 

 upper portion, and resembles No. 2 of the above section. 



The following is a section at the old brick brick yard, on the Daingerfield 

 road: 



1. Brown or brownish yellow brick clay 4 feet. 



2. Light blue or gray colored clay 14 feet. 



Near Black Cypress Bayou the exposure gives the following: 



1. Brownish yellow brick earth or clay ...... 3 feet 



2. Light blue clay 4 feet. 



On the Jefferson and Daingerfield road these clays are exposed for nearly 

 two miles beyond Jefferson. These clays are also found in many places in 

 the town of Jefferson, particularly in the region of the railway station of the 

 Texas and Pacific Railway. 



From their general elevation these beds appear to lie among, or at the base 

 of the red and white sands found in the railway cutting three miles further 

 north. 



The area underlaid by these clays (the lower division), and in which work- 

 able beds may be found, cannot be definitely stated, but will probably exceed 

 two square miles, although, owing partly to the irregularity of the surface 

 and partly to the uneven and irregular surface of the clay beds themselves, 

 some portions of the deposit will be found lying too deep for practical pur- 

 poses. Where the stripping does not exceed four or five feet, or where the 

 upper surface is suitable for the manufacture of ordinary building bricks, a 

 somewhat greater thickness may be profitably worked, provided the brick 

 earth can be utilized to a sufficient extent to pay the cost of laying bare the 

 lower and more valuable clays. 



Three bricks, each measuring 3x2x1 inches, were made from these clays 

 and submitted to a partial test of their fitness for the manufacture of earth- 

 enware and fire bricks. These bricks, after being allowed to dry in the air 

 for four or five hours, were placed in an air bath at a temperature of 110- 

 115° C, and after being kept in this position for two days they were placed 

 in the muffle of an assay furnace. Here the heat was gradually increased 

 until it was raised to a white heat. The furnace was then closed and this 



