402 CLAYS AND CLAY INDUSTRY. 



up to- a plastic mass in the laboratory had an air shrinkage of 6.6 

 per cent. Its tensile strength was no to 130 pounds per square 

 inch. 



It behaved as follows in burning : 



Burning test of a clay from Winslow. 



Cone 15 8 



Fire shrinkage, 54% 6.0% 6.4% 



Color, deep buff yellow brown deep buff 



Condition, steel-hard slightly absorbent slightly absorbent 



The clay was thoroughly viscous at cone 27, hence it is not a 

 fire clay. 



Blue Anchor. — Considerable clay, partly for terra cotta, has 

 been dug around Blue Anchor, and shipped from there. One of 

 these pits (Loc. 202), not being worked in 1902, showed at least 

 9 feet of light, bluish-gray clay, with yellow sandy clay in places. 

 Above this is 2 to 3 feet of pebbly sand. A small sample (Lab- 

 No. 692) that was taken for a partial test, worked up with 38.2 

 per cent, water and had 7.3 per cent, air shrinkage. Its average 

 tensile strength was fair, being 146 pounds per square inch. It 

 burned as follows : 



Burning test of a terra-cotta clay, Blue Anchor. 



Cone 5 8 10 



Fire shrinkage, 6.3 % 7-6% 9.2 % 



Absorption, 5.09% 4.3% 1.90% 



Color, buff buff deep gray buff 



This could be classed either as a terra-cotta clay or buff-brick" 

 clay. It is not a fire clay. 



Another pit (Loc. 204) is intermittently operated by Wm. 

 Brimfield, along the railroad. 



Prof. Cook noted 1 the occurrence of clay near Conrad, one 

 mile south of Tansborough. The clay was dug at one time to 

 make pipe, terra cotta and fire brick, and the section given was : 



Stripping, 6 in. to 3 ft. 



Clay, .: 5 to 16 ft. 



White and yellow quartz sand. 



1 1878 Report on Clays, p. 258. 



