374 CLAYS AND CLAY INDUSTRY. 



Analysis of a glacial brick clay 1 from Garfield. 



Silica (S1O2), 73-71 



Alumina (AI2O3), 11.09 



Ferric oxide (Fe20 3 ) , 4.30 



Lime (CaO), 2.31 



Magnesia (MgO), 1.71 



Potash (K2O), 1.87 



■Soda (Na 2 0), 1.42 



Combined water (H2O), 3.93 



Total, 100.34 



Total fluxes, 1 1.61 



This would indicate a red-burning clay, fusing at a low tem- 

 perature. 



Kingsland. — At Kingsland the red Triassic shale is used for 

 brick. The rock is here a moderately thick-bedded, brownish- 

 red shale, more earthy and less sandy than at many localities in 

 the State, but not exceptionally so. The quarry has been opened 

 in the face of the high bluff bordering the Haekensack meadows, 

 and closely adjoining the D. L. & W. railroad, so that facilities 

 for handling the raw material and shipping the product are unex- 

 celled. Inasmuch as the raw material has to be crushed and 

 ground, an expense not present in the manufacture of brick from 

 soft clay, it is essential that there be economy in other directions 

 in order to compete successfully with clay-made brick. This fact 

 may prevent the utilization of the red shale at many localities 

 where it is otherwise available. 



Samples of the shale which had already been crushed, ground 

 and made into a green brick were tested with the following 

 results. When mixed with 21 per cent, of water it gave a mass 

 of fair plasticity, containing considerable grit, but of low air 

 shrinkage, only 2 per cent. The average tensile strength was 150 

 pounds per square inch, with a maximum of 164 pounds, the 

 number of samples tested being 12. At cone 05 the fire shrinkage 

 was 2 per cent., color brownish red and the absorption 6.56 per 

 cent. The bricklet was barely scratched with steel. Some cracks 

 were developed in burning. At cone 03 the fire shrinkage was 



1 Analysis furnished by Campbell, Morrell & Co., Passaic, N. J. 



