90 REVIEWS 



McCallie, S. W. So7ne Notes ott the Trap Dikes oj Georgia. American 

 Geologist. Vol. XXVII, pp. 133-4. Pis. XII-XIV, March, 1901. 

 Notes on the distribution and cliaracter of the trap dikes, which are possibly of 



Triassic age. 



MiDDLETON, J. Statistics of the Clay -Working Industries in the United- 

 States in igoi. Extract from Mineral Resources U. S. for igoi. 8vo, 

 pp. 78, igo2. 

 The total value of clay products in the United States during 1901 was ^11 0,2 11,587 ; 



the number of firms reporting being 6,421. 



Newberry, S. B. Fuel Cotisuniptioji ift Portland Ceme7tt Bzirfting. Reprinted 

 July, 1 90 1, from Cement and Engineering News. 8 pp. 

 Discussion of the theoretical and actual fuel requirements of the various types 

 of kilns in use, and of the effects of the different methods of mixing the slurry. 



Newberry, S. B. [^Production of'\ Portland Cemettt [in the U. S. during 

 iQo6\. Mineral Resources U. S. for igoo, pp. 737-44, igoi. 

 Resume of condition of American Portland cement industry during 1900, with 



statistics of production. A discussion of fuel consumption is given, abstracted from 



the previous paper. 



Parsons, A. L. Recent Developments in the Gypsum Indtcstry in New York 

 State. Twentieth Rep. N. Y. State Geologist, pp. r. 177-r. 183. 

 Descriptions of the gypsum deposits at Fayetteville, Union Springs, Marcellus, 

 Mumford, andOakfield; with notes on the technology of calcined plaster — the manu- 

 facture of which has recently become an established industry in the state. 



RiES, H. Occurrence of Glass- Pot Clays in the United States. Extract from 

 Mineral Resources U. S. for igoi. 8vo, pp. 17, igoo. 



Glass-pot clays should be highly refractory, very plastic ; dense burning, low in 

 flexing constituents and silica, and high in tensile strength. These requisites are 

 briefly discussed, and certain typical foreign pot-clays are described in detail. Ameri- 

 can pot-clays are derived from the Carboniferous of Pennsylvania and Missouri, 

 occurring in close association with other refractory clays. Analyses and tests of a 

 number of these domestic materials are given. 



RiES, H. The Production of Flint and Feldspar in igoi. Extract from 

 Mineral Resources U. S. for igoi. 8vo, pp. g, igo2, 



A quantity of 34,420 short tons of "flint" (quartz), valued at $149,297, was pro- 

 duced in the United States during 190 1. This was mined in Maine, Massachusetts, 

 Connecticut, New York, Pennsylvania, Maryland, and Wisconsin ; and is largely 

 utilized in potteries and in the manufacture of wood-fillers and scouring-soaps. 



Feldspar was produced in Maine, Connecticut, New York, Pennsylvania, and 

 Maryland, the total amount being 37,741 short tons, valued at $220,422. It is used in 

 the manufacture of pottery, wood-fillers, scouring-soaps, and glass. 

 Russell, I. C. The Portland Cement hidustry in Michigan. Twenty- 

 second Ann. Rep. U. S. G. S., Part III, pp. 62g-85. 



Brief notes on the history of the Portland cement industry in Michigan and the 

 general technology of Portland cement are followed by detailed discussions of the 



