Feather stonhaitgh^s Geological Report. 159 



to its development wherever it may be. When the present 

 veins are exhausted, shafts will be sunk still deeper. There is 

 in fact good reason to believe that the whole distance between 

 the lead mines of Missouri and those of Dubuque's, is com- 

 prehended in the galeniferous formation. At Mineral point, 

 a day's ride from Galena, there are also copper veins, indica- 

 tions of which I saw in coming down the Wisconsin. The 

 veins are nearly vertical, and the carbonate produces thirty- 

 five per cent, of copper. 



The Mississippi, from Fever river, continues about the usual 

 breadth, but has comparatively few islands in it ; the country 

 is exceedingly beautiful, the banks abounding in gentle slopes, 

 with scattering trees and occasional escarpments. In the 

 vicinity of Rock river bituminous coal is found in many places, 

 lying in the beds of the carboniferous limestone on both sides 

 of the Mississippi, like those previously described in the State 

 of Illinois. At the foot of the Des Moine rapids, near the place 

 called Keokuk, the beds of carboniferous limestone are full of 

 siliceous geodes, some of them a foot in diameter, and of great 

 beauty and variety. In some instances I found the geodes 

 containing accidental minerals ; pearl spar covering the faces 

 and terminations of the quartz crystals, and this again sprinkled 

 over with a profusion of minute cubes of sulphuret of lead. 

 Continuing down the Mississippi, along the bluff of the carbo- 

 niferous limestone, and passing the mouth of the Missouri, I 

 reached the city of St. Louis, in the State of Missouri. 



From this place the geology of the country south to Red 

 river, and southeast to the Atlantic, has been already sketched 

 out it my report of 1835. 



I have the honor to remain, 



Very respectfully, sir, 



Your obedient servant, 

 G. W. FEATHERSTONHAUGH, 



U. S. Geologist. 



