Report of the Director. 9 



Michigan, representing nearly every mine at present worked in the 

 county. 



This acquisition is due to the kindness and liberality of Hon. 

 Samuel J. Tilden, of New York, whom I met in Chicago, in July, 

 when he invited me to accompany him to the iron region, in which 

 he has large interests, and was therefore able to extend to me everj'- 

 facility for exploring and making collections nnder the most favorable 

 circumstances. My expressions of obligation are likewise due to 

 Hon. William B. Ogden, and to Mr. Ely, the president of the Mar- 

 quette and Ontonagon railroad ; the latter giving free transportation 

 to myself and collections while in the country. My thanks are 

 personally due to Mr. Wetmore, the agent of the New York Mine; 

 to Mr. Isham, superintendent of the Pioneer Furnace ; to Mr. 

 Mathews, superintendent of the Jackson Mine ; to Mr. Breitung, 

 owner of the Washington Mine, and to many other gentlemen of the 

 iron region. 



Major T. B. Brooks, of the geological survey of Michigan, aided 

 me very materially in visiting localities and in securing collections 

 representative of the ores and the rock formations, as well as in freely 

 communicating the results of his observations upon the geological 

 formations. 



The collection altogether is very extensive, embracing a pretty 

 complete lithological collection in duplicate of all the rocks of the 

 Huronian system as developed in the Marquette iron region, and a 

 large series of the iron ores of the different mines, with some of the 

 characteristic rocks associated with them. Many specimens from 

 the New York Mine are finely crystallized and present a beautiful 

 contrast with the usually compact form of the ore. The collection 

 of ores is sufficiently abundant to afford specimens for distribution 

 among such educational institutions as the Jlegents may please to 

 direct. 



There are minor acquisitions to the Museum which I need not 

 enumerate in this place, but which will appear in the schedules 

 accompanying the report. 



Field Investigations. 

 In my report of last year I communicated some observations on 

 the relations of the Oneonta Sandstone to the Hamilton and Che- 

 mung groups of New York, and I have given farther attention to 

 this subject during the last summer and fall. 



