56 NEW YORK STATE MUSEUM 



Bibliography 



Eckel, E. C. Cement Materials and Industry of the U. S. U. S. Geol. Sur. 



Bill. 243. Wash. 1905. 

 Lewis, F. H. Manufacture of Hydraulic Cement in the U. S. The Mineral 



Industr3^ v. 6. 1897. 

 Ries, H. & Eckel, E. C. Lime and Cement Industries of N. Y. N. Y. State 



Mus. Bui. 44, 190 1. 



CLAY 



The manufacture of brick and other clay products is the most 

 important branch of the mineral industry in Nev/ York. Clay 

 deposits suitable for making the common wares are distributed 

 throughout every section in practically inexhaustible quantities. 

 The rapidly growing market for these products has led to the estab- 

 lishment of numerous manufacturing plants in recent years, so 

 that now there is scarcely an industrial center of any size in which 

 they are not produced. This is particularly true with regard to 

 the manufacture of building materials, which are being employed 

 more and more widely as an element in permanent construction. 

 Owing to their cheapness, durability and the convenience with 

 which they can be adapted to meet the varied architectural require- 

 ments, the use of these materials will doubtless continue to expand 

 for a long time to come. 



The manufacture of the finer grades of clay wares has not devel- 

 oped so rapidly as the other lines. In contrast with most of the 

 states along the Atlantic seaboard. New York possesses almost no 

 deposits of kaolin in quantity to be of economic value. This fact 

 has hitherto retarded the establishment of industries in which kaolin 

 is employed, but with improved facilities of transport, the deficiency 

 has become less formidable to local manufacturers. There are now 

 several plants in the State making tableware, electrical supplies and 

 other porcelain and semiporcelain wares. 



Occurrence and character of clays 



The distribution of clays in New York, as well as their character, 

 uses and industrial development, has been fully described in a 

 report by Heinrich Ries to which reference will be found under the 

 bibliography. The following resume is largely based on data con- 

 tained in that report. 



The soft plastic clays, as distinguished from shale, have been 

 deposited in the more recent geologic periods, ranging from Cre- 

 taceous to the present. The period of most abundant deposition 

 is the Quaternary, to which age belong all the clays of the mainland 

 so far as known. Cretaceous clays have a limited distribution on 



