410 CLAYS AND CLAY INDUSTRY. 



Burning tests of a clay west of Millville. 



Cone 5 Cone 8 



Fire shrinkage, 34% 4% 



Color, light buff buff 



Condition, steel-hard steel-hard 



Absorption, 946% 8.78% 



It is not unlike other Cohansey clays used for terra cotta, and 

 might fairly be classed as a terra-cotta clay. 



South of Millville (Locality 178), on the road to Buckshutem, 

 the clay is exposed in a pit on the west side of the creek. It 

 is bluish above and black below, and has a thickness of not less 

 than 7 or 8 feet. The amount of stripping, however, is as much 

 as 12 feet, and it probably would not pay to< mine the clay unless 

 some use were found for the overlying sand. The clay is also 

 wet in places. If the deposit on further prospecting were found 

 desirable to work, there would be but a short haul to* the Maurice 

 river where it could be loaded upon scows for shipment. The 

 clay (Lab. No. 671) is gritty, with an air shrinkage of 7.3 per 

 cent, and it takes 31.7 per cent of water for mixing. It burned 

 steel-hard, however, at cone 1, with a fire shrinkage of 3.7 per 

 cent., although the clay was still absorbent (8.25 per cent.). At 

 cone 10, it was vitrified, gray in color, and had a fire shrinkage 

 of y.y per cent. 



Another deposit of Cohansey clay has been worked 3 miles 

 east of Millville (Loc. 187). The material from there has been 

 shipped to the Perth Amboy Terra Cotta Company at Perth 

 Amboy, but the pit was idle in 1902. The clay is not unlike 

 many of the Cohansey clays already referred to, being dense, 

 tough and gritty, with occasional sandy streaks. At the bottom 

 of the pit there is a black lignitic clay. The light clay is about 

 6 feet thick with several feet of sandy overburden. 



The clay when worked up with 34 per cent, of water had a 

 rather high air shrinkage, viz., 8.6 per cent., and an average 

 tensile strength of 155 pounds per square inch. Its behavior in 

 burning was as follows : 



