40 NEW YORK STATE MUSEUM 



ores and of mineral products in first marketable forms was valued 

 at $35,988,407, a total equal to that of the preceding year, but 

 rather below the normal output. It was an exceptional season, 

 marked by great prosperity in certain branches of industry and 

 by equally great depression in others, such contrasting conditions 

 as have scarcely been witnessed in any previous period. There 

 was a notable revival of activity among the iron ore properties 

 which will probably lead to a new record in the output for the 

 current year, and some expansion in other lines; but the market 

 for building materials (stone, clay and cement) was poor and 

 led to decreases in these important items of local productions. 



A new industry came into existence in 191 5 with the inaugura- 

 tion of zinc mining in the Edwards district of St Lawrence 

 county. The first ore shipments (several thousand tons for the 

 year) are an earnest of a substantial increment in the State's 

 developed resources. The district has long been known for its 

 valuable talc deposits, but the value of the metallic minerals, which 

 include both pyrite and zinc, has only recently gained recognition. 



Quarry materials. An appraisal of the quarry resources that 

 are contained in the crystalline formations, mainly Precambric, 

 was published during the year as Bulletin 181 of the State Museum. 

 The various kinds of products derived from these formations are 

 granite, gneiss, marble, trap and pegmatite, all of which have con- 

 siderable commercial importance. Their distribution and local 

 development are presented comprehensively ; and some of the more 

 attractive building or monumental stones are reproduced, as faith- 

 fully as may be, in color. The description of the local features is 

 preceded by a general discussion of the fundamental geological 

 structures of the State as a key to the distribution of the resources ; 

 and by chapters on the qualities, physical and chemical, which 

 determine the value of stone for different uses, and the methods 

 available for their discrimination in the held and laboratory. 



Zinc ore investigations. Steps have been taken to meet the 

 call for information, which has come to the department from all 

 directions, in regard to the general features of the zinc ore occur- 

 rences in the Edwards district and their probable economic impor- 

 tance. In addition to the areal mapping of the region now in pro- 

 gress, it is purposed to carry out a special investigation of the 

 more limited area in which the ores occur. The necessary field 

 work for this investigation, in fact, has already been practically 

 completed. Short summaries of the developments and geological 



