6OO CLAY, ROAD MATERIALS, ETC. 



Rattler Test. 



No. of Weights. Per cent. 



Brick. Initial. Final. Lost. 



9 10 11 12 



10 60.02 42.78 28.72 1 Brick broke in test. 



10 59.84 43.54 27.24 1 Brick broke in test. 



Average 27.98 



Absorption. Wet, Test begun May 18th, 1915. 



Per cent. Dry, Ibs. Ibs. Gain, Ibs. Completed, May 21st, 1915. 



4.11 30.36 31.50 1.14 Made on 5 unrattled brick. 



4.04 43.54 45.30 1.76 Made on 10 rattled brick. 



Average weight of one dry brick=-5.99 Ibs. 



The shale as tested above is a little too low in the Modulus 

 of Rupture and Rattler tests to conform to the specifications 

 for highway brick recommended by the State Road Engineer, 

 but this may be partly due to improper burning of the brick 

 as they were fired at the plant of a firm that is making com- 

 mon building brick, and under proper conditions, this defect 

 might be remedied. The brick burn to a rich red color that 

 would be fine for residence purposes. The following addi- 

 tional test for shrinkage and porosity, made of the same shale 

 by the U. S. Bureau of Standards at Washington, D. C, was 

 furnished by Mr. Williams, as follows : 



"DEPARTMENT OF COMMERCE 

 "Bureau of Standards. 



"Washington, June 30, 1915. 

 "Mr. A. D. Williams, 



"W. Va. State Road Bureau, 



"Morgantown, W. Va. 

 "Dear Sir: 



"We beg leave to report upon the sample of shale which vou sub- 

 mitted some time ago for test. This material developed good working 

 plasticity and can be pressed easily in a stiff mud machine. No drying 

 difficulties were encountered. The water of plasticity was found to be 

 18.4 per cent, and the linear drying shrinkage 3.6 per cent. Specimens 

 were made and fired at a number of temperatures and the porosity, 

 color and burning shrinkage determined. These results are compiled 

 in the following table: 



Per cent. Per cent. 



Temp. C. Porosity. Color. Burning Shrinkage 



1050 15.2 Red- Vitrified 6.18 



1075 8.53 do 



1100 6.77 do 



1125 6.07 do 



1150 5.59 do 7.82 



1175 4.76 Dark-Vitrified 



1200 6.50 do 



1225 11.20 do overburned 



1240 13.80 do do 3.29 



