52 .GEOLOGICAL REPORT. 



tending northwardly into the Bennett tract, of not less than one 

 mile in length. The fissure varies in width from one to fifteen 

 feet ; and at one point, at which it is still visible from the top 

 of the shaft, is not less than two feet wide. The rock is cover 

 ed with a thick, heavy bed of ferruginous clay, the average 

 thickness of which is fifty feet, beneath which is some ten or 

 twelve feet ofcherty limestone, and below this is the magnesian 

 limestone. The fissure is filled with clay, heavy spar, (some 

 of which was well crystallized, mostly, however, amorphous, 

 with a light sky-blue color,) and with galena. 



&quot; From this section it will be seen that the shafts sunk were 

 very numerous ; but, doubtless, before the possession of the 

 mine by the Meramec Company, most of them were sunk with 

 out regard to any system or regular mining operations. After 

 the company took possession, the mining was more systema 

 tic, and most of their labor was confined to the neighborhood 

 of the engine and north shafts, each of which was sunk to a 

 depth of about 260 feet. Levels were cut from north shaft, 

 both north and south, the latter communicating with Duguid 

 and Prior s shaft. Dr. King, in his report, says that between 

 engine and north shaft there was a vast cavern, extending from 

 the first level connecting these two shafts, almost to the sur 

 face of the ground, with an average breadth of nearly five feet, 

 and from fifty to one hundred feet in height, nearly filled with 

 pure galena ; and that in the engine shaft, at the depth of 260 

 feet, the lode was as large and distinct as it generally was 

 throughout the shaft. 



&quot;Before the operations of the Meramec Company, the mining 

 was carried on at different points by different parties, acting 

 without regular system, and the one independently of the 

 other. Most of the mineral, I doubt not, was then obtained 

 from comparatively shallow depths. How much of this fissure 

 has been worked out along its course, so far as yet explored, 

 and to the depth of the deepest shafts, I have no sufficient data 

 to enable me to judge ; but from the best information I have 

 been enabled to obtain of the levels and the stoping, I should 

 deem it an exaggerated estimate to place it at one-half. 



&quot; Of the total amount of mineral obtained here, it is, perhaps, 

 impossible at present to obtain any true and accurate state 

 ment. Dr. King, who had an opportunity, about ten years ago, 



