CLAYS OF BURLINGTON COUNTY. 379 



Assiscunk creek. — Some buff-burning clay is found on Assis- 

 cunk creek, i 1 /* miles east of Burlington (Loc. 120), on. prop- 

 erty belonging to Jos. Scott. Since the outcrop consists chiefly 

 of red-burning clays it is mentioned in more detail below. The 

 properties of the buff-burning clay are given here. It (Lab. No. 

 623) is a yellowish-white, gritty fast-slaking clay with little mica. 

 It took 19.2 per cent, of water to temper it, and its air shrinkage 

 was 4.6 per cent. The average tensile strength was 95 pounds 

 per square inch. It was burned with the following results : 



Burning tests of clay from Jos. Scott's property, near Burlington. 



Cone. 05 5 8 10 



Fire shrinkage, 1.4 % ■ 2 % 4 % 5-4 % 



Absorption, 15.01% 10.25% 5-25% S-°7% 



Color, buff deep buff deep buff with buff 



tiny specks 

 Condition, not steel-hard steel-hard 



The red-burning type of Raritan clay, mentioned as occurring 

 in Burlington county, is found on Assiscunk creek, 1^2 miles east 

 of Burlington. One exposure (Loc. 120) forms a considerable 

 bank on the south side of the creek on Jos. Scott's property, and 

 lias been dug from time to time for foundry purposes. The 

 material consists of alternating layers of light, yellowish-white, 

 mottled clay and red clay spotted with white, while near the top 

 of the bank is a white sandy clay. It is doubtful if the different 

 grades could be separated in mining without considerable trouble 

 and the bank as a whole would probably not average better than a 

 low grade of -No. 2 fire clay at the very best. 



Two samples were tested, one representing the run of the bank 

 and the other the whitish clay (see above), which appears about 

 twelve feet above the creek. The former (Lab. N0 1 . 654) is fairly 

 plastic, slightly gritty clay, with no mica and red and white mott- 

 lings, and slakes slowly. It works up with 23.8 per cent, of 

 water to a mass having an air shrinkage of 5 per cent. Its 

 average tensile strength was 80 pounds per square inch. When 

 burned the following results were obtained: 



