Note by the Director. 



The study of the Quaternary deposits of the Hudson River valley was under- 

 taken by me several years ago, and a paper on the subject was published in 

 the American Journal of Science.* In continuation of this it seemed import- 

 ant to investigate the economic side of the question and report on the brick 

 industry, which is so highly developed in this region. The confining duties 

 of administrative work in the museum rendered it necessary for me to delegate 

 the work of the economic investigation, and it was placed in the hands of Mr. 

 Heinrich Ries, Ph. B., who, during the summer of 1891, made a careful study of 

 the methods of brick manufacture in the Hudson River valley, and extended 

 the investigation of the Quaternary geology of this region, f During the season 

 of 1892, the necessity for making a representative collection of clays through- 

 out the State of New York, for the World's Columbian Exposition, afforded an 

 opportunity for obtaining information concerning the clay industries of the 

 interior of New York and of Long Island. As the result of his work conducted 

 during these two seasons, Mr Ries has prepared the following report. Nearly 

 every locality of importance in the State has been visited, and as it is the only 

 exhaustive report on the subject which has been prepared in this country, it 

 commends itself to all who seek information concerning the industrial uses of 

 clay in New York. 



F. J. H. MERRILL, 



Director. 



PREFACE. 



The following report is intended to deal chiefly with the 

 economic aspect of the subject. In the time at my command it 

 has not been possible to visit all the deposits which are being 

 worked, and, therefore, much information has necessarily been 

 gathered by correspondence. The analyses given in the report 

 have all, unless otherwise stated, been made by Dr. H. T. 

 Yulte, of Columbia College, New York city. All the methods 

 described for obtaining the raw material and working it up to a 

 finished product are those employed in the State of New York. 



The writer wishes to express his thanks to Dr. F. J. H. 

 Merrill for suggestions offered during the course of the work. 

 Credit for assistance rendered is due to Messrs E. J. Riederer, 

 of New York city, C. L. Sanford of Southold, L. L, E. J. Burke 



•Vol. XLI, June, 1891. 



tThe results of this work were published in the Annual Report of the State Geologist for 1890. 



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