568 abstracts: technology 



only in recent years since the metalliferous deposits of the lower Yukon 

 and Kuskokwim regions have been studied that the importance of the 

 Tertiary period of mineralization has been recognized. Localities in 

 this general province as widely separated as the lower Kuskokwim and 

 northern British Columbia are now known to have been mineralized 

 in Tertiary time, but between these localities there are mining districts 

 in which the metallization is of Mesozoic age. Thus there seems to 

 be here an overlapping of the two metallogenetic provinces. Like the 

 Mesozoic mineralization, that of Tertiary age is genetically connected 

 with granular acidic intrusive rocks, but the later intrusives seem to 

 have been less widely distributed than the earlier. 



It should be noted that though mineralization accompanied the Ter- 

 tiary intrusives, no metalliferous lodes have been found in the Tertiary 

 sediments. It appears that the conditions for the formation of the 

 metalliferous veins necessitated a deeper cover than that furnished by 

 these beds. A. H. B. 



ENGINEERING.— Surface water supply of the United States, 1914. 

 Part III. Ohio River Basin. Nathan C. Grover, et al. U. S. 

 Geological Survey Water-Supply Paper 383. Pp. 121, with two 

 illustrations. 1916. 

 This volume is one of a series of reports presenting results of measure- 

 ments of flow made on streams in the Ohio River Basin during the year 

 ending September 30, 1914. It includes also a list of the stream gag- 

 ing stations and publications relating to water resources in this Basin. 



O. E. M. 



TECHNOLOGY. — The correlation of the mechanical and magnetic prop- 

 erties of steel. Chas. W. Burrows. Bureau of Standards Sci- 

 entific Paper No. 272, pp. 173-210. 1916. 

 This paper is a review of the work done in correlating the magnetic 

 and mechanical properties of steel with special reference to the commer- 

 cial application of the magnetic data as criteria of the mechanical fit- 

 ness of a given steel and of magnetic changes under stress as indications 

 of the state of strain. C. W. B. 



