586 REPORT OF NATIONAL MUSEUM, 1904. 



throughran act of the legislature, establishing ;i board of survey, con- 

 sisting- of the governor of the State, the president of the board of 

 education, and the superintendent of public instruction, with power 

 to select geologists, disburse the money appropriated, 

 of M^chigln^soT. an( l perform other necessary acts. Under this law 

 Prof. Alexander Winchell was again made director, and 

 undertook himself the investigation of the Lower Peninsula, with the 

 assistance of his brother N. II. Winchell, M. W. Harrington, E. A. 

 Strong, A. M. Wadsworth, C. B. Headley, A. O. Currier, and J. H. 

 Emerson. Later (1873-1876), after Winchell's retirement, C. Romin- 

 ger was appointed by the board to work on the Lower Peninsula also. 



To Maj. T. B. Brooks, as a State geologist, was assigned the survey 

 of the iron regions; to Raphael Pumpelly that of the copper regions 

 of the Upper Peninsula, and to Carl Rominger a study of the Paleozoic 

 rocks and their associated fossils. Brooks's report, submitted in 1873 

 and forming part one of the first volume of the reports of this survey, 

 was written with the idea of making it "as complete a manual as pos- 

 sible of information relating to the finding, extracting, transporting, 

 and smelting of the iron ores of the Lake Superior region. " With 

 this in view, he presented in the order here given, first, an historical 

 sketch of the discovery and development of the iron mines; second, 

 the geology of the Upper Peninsula, including the lithology; third, 

 the geology of the Marquette iron region; fourth, the geology of the 

 Menominee iron region; fifth, the Lake Gogebic and Montreal River 

 iron ridge; sixth, a chapter on exploration and prospecting for ore; 

 and seventh, the magnetism of rocks and use of the magnetic needle in 

 exploring, concluding with chapters on the method and cost of mining 

 specular and magnetic ores and the chemical composition of the ores. 



The lithological work on the rocks of the region was performed by 

 A. A. Julian, of New York, his report forming the second volume 

 (298 pages) of the survey. 



Brooks's work contained scarcely anything of a speculative nature 

 and but little as to the origin of the ores themselves. 

 Brooks's work. With reference to the association of magnetic and 

 specular ores, he wrote: 



If we suppose all our ores to have been once magnetic, and that the red specular 

 was first derived from the magnetite and the hydrated oxide (soft hematites) in turn 

 from it, we have an hypothesis which best explains many facts and will he of use to 

 the explorer. 



Again, with reference to the ore of the Negaunee district: 



If we suppose tepid alkaline waters to have permeated this formation and to have 

 dissolved out the greater portion of the siliceous matter, leaving the iron oxide in 

 an hydrated earthy condition, we would have the essential character exhibited by 

 this formation as developed on the New England, Saginaw range, and, as will be 

 seen afterward, at the Lake Superior mine. This is offered not so much as an 

 hypothesis to account for the difference as to illustrate the facts observed. 



