iv Preface. 



The full descriptions of the mines, the discussion of the structural 

 features of the ore beds and deposits, and their geological relations, 

 with notes on the geology of the districts in which they are found, 

 are omitted. The season was too short for the additional work of 

 studying the varying modes of occurrence of the several kinds of 

 ore in all of the iron-ore districts. They may make the subject of a 

 second report, in a future bulletin. 



It is proper and pleasant to refer here to the prompt and uniformly 

 kind courtesy of all the mine owners, superintendents and other 

 officials, and of the furnace managers also, who have responded so 

 fully to the circular letters sent to them, and to acknowledge their 

 generous aid in affording every facility for seeing the mines under 

 their care, without which the preparation of this report would have 

 been an impossibility. 



JOHN C. SMOCK. 

 Department of Mineralogy 



and Economic Geology, 

 N. Y. State Museum. 



Albany, June, 1889. 



