546 REVIEWS 



Scattered notes on various Pennsylvania road materials, with a section on the distri- 

 bution, by counties, of such materials. 



Lewis, F. H. Hydraulic Cement Industry in the United States in i8gg. 

 Mineral Industry, Vol. VIII, pp. 84, 85, 1900. 

 Resume of progress in the American cement industry during 18Q9. 



Cement Industry in the United States in /goo. Mineral Industry, Vol. IX, 



pp. 77-82, IQOI. 

 Resume of the conditions of the American Portland cement industry during 1900 — 

 a year marked by overproduction and low prices. 



Lewis, F. H., Newberry, S. B., and others. The Cement Industry. 8vo. 

 Pp. 235, Figs. 152. New York, 1900. 

 A collection of articles reprinted from issues of the Engineering Record. Detailed 

 descriptions of a number of American cement plants, with sketches of the condition of 

 the cement industry in various European countries ; and separate chapters on the gen- 

 eral technology of Portland cement (Newberry) and the rotary kiln process (Lewis). 



Merrill, G. P. Guide to the Study of the Collections in the Section of 

 of Applied Geology ; the Non-metallic Minerals. Rept. U. S. Nat. Mus. 

 for 1899. Pp. 155-483, Pis. 1-30, 1901. 

 Comment. — The material contained in this handbook cannot well be summarized. 

 The sections of interest in the present connection are those on quartz (p. 215); flint 

 (216); limestones, mortars, and cements (pp. 264-270); dolomite (p. 274); magnesite 

 (p. 275); feldspars (p. 281); claya (pp. 325-353); gypsum (pp. 406-411); and road- 

 making materials (p. 482). The treatment of these subjects is, in general, excellent, 

 that of clays being eminently so. The discussion of the cements, particularly Port- 

 land, is less satisfactory. 



Newberry, S. B. [Production of\ Portland Cement \in the United States 

 during i8gg\. Twenty-first Ann. Rept. U. S. Geol. Surv., Pt. VI con- 

 tinued. Pp. 393-406, 1901. 

 Resume of the condition of the American Portland cement industry during 1899, 

 with statistics of production. The method of calculating the proportions of the ingre- 

 dients in a Portland cement mixture is discussed and exemplified. 



Ries, Heinrich. Clays of New York. Bulletin 35, New York State 

 Museum. 8vo, pp. 455, Pis. 140, map, 1900. 



Detailed discussion of the origin, properties, testing and uses of clays, and manu- 

 facture of clay products ; with descriptions of the clay deposits of New York and of 

 the industries based on them. The section on the geologic distribution of clays in 

 New York (pp. 275-311) is here summarized, together with the sections on shales 

 (pp. 825-841) and feldspar and quartz (pp. 841-844). 



Small deposits of residual clay, of little or no economic impoitance, have been 

 found at various points in Dutchess county. 



The sedimentary clays are numerous and important, representing three geologic 

 periods — -Quaternary, Tertiary and Cretaceous. The latter two occur only on Long 

 and Staten Islands, all the clays of the mainland being Quaternary. 



