394 CLAYS AND CLAY INDUSTRY. 



mixed up with 17.7 per cent, of water; it had an air shrinkage of 

 2 per cent., which is low and due to its sandy character. 



At cone 3 its fire shrinkage was 1.3 per cent., and its absorption 

 15.41 per cent. It would probably have to be burned to cone 8 or 

 10 to produce a dense bricklet. Even at cone 3 it is not steel-hard. 



Its chief application is for foundry work, but it could also be 

 used in the manufacture of terra cotta, as a low-shrinkage in- 

 gredient. 



Fish House. — Two other lense-like deposits of Raritan clay 

 were seen, one about one-third mile south of Fish House station 

 (Loc. 135), and the other (Loc. 136) the same distance southeast 

 of that locality. At the former point the clay outcrops in a cut- 

 ting along the roadside. It is a bluish-white, sandy clay, forming 

 a lense probably 8 feet thick, and while not of great length or 

 thickness, still there are additional lenses of clay in the vicinity .. 

 The overburden is not very heavy. A similar mass of clay is 

 found in a pit about 1,000 feet north of the road. This clay, like 

 the preceding, was quite free from mica. The character of this 

 clay (Lab. 643), which was quite plastic, was as follows: Water 

 required for mixing, 21.9 per cent. ; air shrinkage, 3.3 per cent. ; 

 average tensile strength, 80 pounds per square inch. 



A sample burned at cone 10 gave 4.7 per cent, fire shrinkage, 

 and had an absorption of 8.52 per cent. It was steel-hard at this 

 temperature and a light-buff color. It became viscous at cone 27, 

 so that it is only a low-grade fire clay. It could be used for terra' 

 cotta or foundry work, and also< for buff brick. 



At the second locality mentioned above there is another lens of 

 Raritan clay, whose thickness is at least 8 feet. The clay is very 

 similar in appearance to that of the preceding locality, but it has 

 several sandy layers near its base, and the overburden varies from 

 5 to 10 feet in thickness. The clay takes only 19.2 per cent, of 

 water to temper it, and its fire shrinkage up to cone 5 is only 2 

 per cent., with an absorption of 12.93 P er cen t- 



Cloy Mori I. 



Camden. — Clay Marl I is extensively used at Budd Brothers' 

 brick works, near City Line station (Loc. 143). The clay bank is 



