CLAYS OF CAMDEN COUNTY. 401 



Cohansey Clays. 



Clays belonging to the Cohansey formation have been dug at 

 several points in southeastern end of the county. 



Winslow Junction, — The most extensive excavations have been 

 made in the immediate vicinity of Winslow Junction (Loc. 201) 

 for supplying the works of the Eastern Hydraulic Press Brick 

 Company, at that point. A large area has been dug over close 

 to the railroad station, and at present another bed has been opened 

 i}4 miles north of the works, and connected with the factory 

 t>y a narrow-gauge railroad. The latter deposit underlies an 

 area of about 20 acres, and ranges from 4 to 7 feet in thickness, 

 with 2 to 3 feet of yellow, sandy overburden. The material is 

 vari-colored, being gray, black and bright yellow with much 

 lignite in places, and is said to be -more plastic than the clay at 

 Whitings or right at Winslow Junction. The pit is operated 

 Avith a long working face. (PI. VII, Fig. 2.) 



The physical properties of this material (Lab. No. 657) are as 

 follows : Water required for tempering, 37.5 per cent. ; air shrink- 

 age, 5.5 per cent. ; average tensile strength, 196 pounds per square 

 inch. The firing tests are given below : 



Burning tests of clay from near Winslow. 



Cone 1 8 15 



Fire shrinkage, 6.5 % 9.1 % 10. % 



Absorption, 12.96% 4.01% 2-37% 



Color, buff buff gray brown 



The clay burned at cone 8 was steel-hard, and that burned at 

 cone 15 showed a blistered surface. 



Some dry-press tile made from the clay, when burned at cone 

 5, gave a shrinkage of 8 per cent., a buff color and were steel-hard, 

 with an absorption of 9.23 per cent. At cone 8 the same tiles 

 burned grayish buff with a shrinkage of 15.6 per cent. The clay 

 before pressing was screened through an 80-mesh sieve. 



Another sample of clay from a pit nearer Winslow Junction 

 was also tested (Lab. No. 411). This sample had been pre- 

 viously ground in a disintegrator and screened, and when worked 

 26 cl, G 



