2J2 CLAYS AND CLAY INDUSTRY. 



Distribution., — Clays for the manufacture of terra cotta are. 

 obtained from several districts in New Jersey, but only from two 

 formations, viz., the Raritan and the Cohansey. The Raritan 

 supplies the greatest quantity of terra-cotta clay, large amounts 

 being- dug in the Woodbridge and Perth Amboy districts, much 

 of it for use in other States. Clays of the same age are also dug 

 to some extent from the pits that have been opened along the 

 Delaware near Palmyra and Bridgeboro. 



The Cohansey clays mined extensively near Woodmansie are 

 employed to a considerable extent for terra cotta, and others dug 

 near Blue Anchor have been used for this same purpose, but in 

 most cases where the Cohansey and Delaware river clays are used, 

 they are mixed with a certain amount from the Woodbridge 

 district. 



TERRA-COTTA MANUFACTURE. 



The manufacture of terra cotta stands on a much higher plane 

 in ceramic technology than it did a few years ago. The grades 

 of clay employed have improved, and the progress that has been 

 made in the number of colors producible and the complex 

 and original designs which can be executed, have called for the 

 employment of highly skilled labor in the execution of the 

 architect's wishes. Indeed, the use of terra cotta for exterior 

 decoration has met with such success, that few modern buildings 

 of large size are erected at the present day without the use of 

 a large quantity of this product. The high development of 

 this branch of the clay-working industry is due no doubt in 

 part to the competition between different manufacturers to meet 

 the demands of the architect. 



It will be easily seen, therefore, that in the manufacture of 

 terra cotta, the labor forms a larg - e portion of the expense. 

 Furthermore, with an increase in the intricacy of design, much 

 greater care has been necessary in the mixing of the clays, for a 

 thorough preparation aids much in the prevention of warping 

 or cracks in burning. Some terra-cotta manufacturers even store 

 their clay in bins for some time after tempering it. 



There are several reasons why terra cotta has taken the place 



