CLAYS OF MERCER COUNTY. 



429 



Section of Smith's pit, Dogtown. 



Stripping, 3 ft. 



Red wad clay, 14 ft. 



No. 1 black clay, 6 ft. 



Black sand, 4^ ft. 



Black earth 



A number of other pits have been dug in this region as shown 

 on the map at localities 100, 103, and 104, and the materials all 

 show the usual variation characteristic of the Raritan beds. The 

 following series of tests fairly represent the properties of these 

 Raritan clays in the vicinity of Dogtown : 



Physical tests on Dogtown clays, J. J. Moon. 



I. No. 1 blue clay, whitish color, with some fine grit, from Dogtown. 

 slaked moderately fast and had tiny limonite specks. J. J. Moon. 



II. No. 1 sagger clay. J. J. Moon. 



III. Tough red wad clay with very little grit. J. J. Moon. 



IV. No. 2 sagger clay. 



It 



Water required, , 



Air shrinkage, 



Average tensile strength, 



lbs. per sq. in., 



Cone 05 : 



Fire shrinkage, 



Absorption, 



Color, 



Condition, 



Cone 03 : 



Fire shrinkage, 



Absorption, 



Color, 



Cone 1 : 



Fire shrinkage, 



Absorption, 



Color, 



Condition, 



Cone 3 : 



Fire shrinkage, 



Absorption, 



Color, 



Condition, 



I 

 Lab. No.' 



62Q 

 18. % 



5-3 % 



85 



7-3 % 



13-0 % 



creamy white 



steel-hard 



II 



Lab. No. 



632 

 28.5 % 

 4.6 % 



90 



1.4 % 



19.82% 



pinkish red 



not steel-hard 



3.0 % 



20.00% 



pinkish red 



6.0 % 



13-63% 



pinkish red 



not steel-hard 



III IV 



Lab. No. Lab. No. 



644 710 

 38.5 % 



6 % 7 % 



72 



8.0 % 



15-39% 



gray 



steel-hard 



9-3 % 



11.73% 



gray 



7.0 % 

 15.08% 



