6(3 THE CRYSTAL FALLS IKON-BEARING DISTRICT. 



Ill May tliey began tlie task of divertiug the cliaimel of the river to a point several 

 hundred feet south of the okl course. They have dredged out a cut 2,G50 feet iu 

 length by 100 feet wide and IS feet deep. At the upper end of the new channel a 

 coll'erdani containing 1J:,000 cubic yards of earth has been coustructed, aud where the 

 waters join the old outlet several hundred feet below the mine another embankment 

 has been constructed across the course of the old bed that has 8,000 cubic yards of 

 earth. This task was a very expensive one, and it has been well completed, the old 

 channel being perfectly dry. 



The turning of the river's course brings out with startling distinctness the criminal 

 negligence or carelessness of those who were working the mine at the time of the 

 accident. The upper tier of timbers in the mine are plainly seen, as also the ground 

 that had been cut out to receive the set that was being gotten into place when the 

 waters broke through. This shows the miners had worked up to within lli feet of 

 the water of the river. A great crack in the formation shows where the water first 

 gained entrance. The ore made up the bed of the stream — was a ijortion of the bed 

 in fact — and the walls of the mine were nearly vertical. The ore deposit had a width 

 of about 20 feet. The water i>ressure must have been considerable, and the blasting 

 of the ore (as it is hard, and explosives are needed to loosen it) shattered the thin 

 protection over the miners, permitting the water to find ready and unimpeded 

 entrance into the mine. An engineer could not have been emiiloyed and the wildest 

 sort of guessing must have been done by those who had the work in charge. 

 No sane man woidd have permitted the opening of the deirosit so near the river's 

 bottom.' 



Owing- to tlie long abaudonmeut of the mine, the direct sources of infor- 

 mation have been closed. For a description of the ore body I am com- 

 pelled to rely on such data as are available from existing notes and plats. 

 I am especially indebted to a rnaimscript description of the mine by 

 J. Parke Channing, and to Mr. C. T. Roberts, of Crystal Falls, for plats of 

 the mine. The sketch of the mine here introduced, PL IX, is compiled 

 from an original drawing of J. Parke Channing, reproduced on the plate 

 cited, and from data obtained from other sources. 



GENERAL DESCRIPTION OF MANSFIELD MINE DEPOSIT. 



The Mansfield mine has an ore body varying from 16 to 32 feet in 

 width. It is in almost vertical position; it has well-defined foot and hang- 

 ing walls composed of impervious rock; it has a somewhat indefinite longi- 

 tudinal extent. The ore is Bessemer and occurs in an iron-bearing formation, 

 which corresponds in every particular to those of tlie other iron-bearing 



' Report of Comiiiissionei' of Mineral Statistics of Michigan, George A. Newett, for 1896, p. 84. 



