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devised and commenced, the immense resources of the beautiful region of 

 country north of the rapids, in IlHnois, Wisconsin, and Iowa, will remain 

 unavailable. In the winter of 1836-'37, f was a witness that $15 were 

 paid for flour, and i$25 for barrelled pork, at St. Peter's, which at St. Louis 

 had probably respectively cost but $5 and $8, because the steamers loaded 

 with winter provision had not been able to cross the rapids during the pre- 

 ceding fall. 



The uplands that border on the rapids are based upon the mountain or 

 ^ carboniferous limestone, as the contained fossils indicate. The 

 e^ ogy. jif^-jgjjtQjjg^ Qf ^ (]irty color, and much broken up, is the matrix of 

 numerous siliceous and calcareous geodes. Those fine geodes picked up 

 by all travellers, are found on the banks of the rapids, having fallen from 

 the adjoining bluflis. Within a few years there has been a road opened 

 leading (o Warsaw, and, being cut along the blufl", has exposed to view 

 the stratum in which the geodes occur, and their position therein. They 

 are observed to be slightly compressed, their greater axes being parallel 

 to ihe stratification of the limestone, which is horizontal. As I have col- 

 lected a number of them, I shall describe mineralogically a few of those 

 that have appeared to me the most interesting in their mineral associations, 

 viz: 



1. Siliceous geodes, the cavity of which is filled with prismatic crystals of 



limpid quartz, (quarz hyalin.) 



2. Siliceous geodes, filled with crystalline quartz, the pyramidical termina- 



tions of which are of a red color. 



3. Siliceous geodes, filled with crystallized calcareous spar, (variety, eyi 



iete f/e clou of Haiiy.) 



4. Silico-calcareous geodes, with rhombic calcareous spar. 



5. Silico-calcareous geodes, with confusedly crystallized calcareous spar. 



6. Siliceous geodes, enclosing calcareous spar and crystalline sulphuret of 



zinc. 



7. Siliceous geodes, containing mamelonated chalcedony, of a red color. 

 These geodes vary in size from four or five inches in diameter to twelve 



or fifteen. 



Warsaw is situated directly opposite the mouth of the Des Moines, 

 ^ partly at the foot, partly on the top of the bluflf that overlooks the 

 Mississippi. This is a very advantageous position, as it forms a 

 natural depot for the products of the back parts of Illinois and those 

 descending the Des Moines. Moreover, it is at Warsaw that the steam- 

 boats that cannot cross the rapids stop, to discharge their cargoes into 

 keel-boats that transfer them to the steamers at the head of the rapids; 

 the same keel-boats bringing, in return, freight for the steamboats on the 

 descending trade. 



Between the lower and upper rapids, a distance of about one hundred 

 and thirty miles, the navigation of the Mississippi is perfectly safe. Its 

 valley swells out considerably, especially about the confluence of the 

 larger rivers coming from the northwest ; the entrances to which are con- 

 cealed by a number of low islands and sloughs, that, at some seasons, aftect 

 the salubrity of the surrounding country. Occasionally, however, the high- 

 lands approach the river, and emigrants take advantage of such positions 

 to multiply the sites of new villages and towns. 



