OGLE COUNTY. 119 



over by me. I had poor facilities for examining the river bed ; but at 

 one locality on the north bank of the stream, five or six miles below 

 Oregon, and just at the edge of rather low water, I found a stratum of 

 stone, apparently in situ, which I believe to have been the top of this 

 formation. I confess, however, that my judgment as to the existence 

 of the Lower Magnesian limestone along the river bed in this county is 

 formed, at least partly, from analogy, appearances, and the natural be- 

 lief that the bottom of the St. Peter's sandstone is here reached. A 

 proper examination of the river bed, or some shallow borings along its 

 shores, would satisfactorily test the matter, and settle any existing 

 doubt. 



Economical and Agricultural Geology. 



Most of my remarks upon the economical and agricultural geology 

 of counties north of this one would apply with equal correctness to 

 Ogle. In physical features, geological formations, and agricultural ca- 

 pabilities, they have much in common. There are some points of differ- 

 ence, however. 



Stvm- fr Econnmk-al tV*. All the limestones afford a good build- 

 ing stone. The seminary building at Mt. Morris, and the new public 

 school at Polo, are tine examples of the building materials furnished 

 by the Blue limestone quarries. The rock is not only strong, easily 

 worked, convenient to obtain, but when properly laid up of blue, or 

 mingled buff and blue colors, the architectural effect is beautiful. The 

 thin-bedded top layers furnish a good stone for the lighter industrial 

 uses. The heavy-bedded, dull colored buff is more used for the heavier 

 kinds of masonry. The Galena in this county is a rough, thick : l>edded 

 stone, used in cellar waUs. bridge foundations, and the common stone 

 work necessary on the farms about its outcrops. In a few places the 

 St. Peter's sandstone has crystaline layers of sufficient tenacity to cut 

 into window and iloor caps, build into cellar walls and dwelling hou - : 

 and in o;ie instance, at least, is used for the culverts in a small railroad 

 bridge. It is easily hewn into shape, and seasons into greater hardness 

 and tenacity. 



i tain layers of the Blue limestone also burn an excellent common 

 lime. The kilns above Dixon. in Lee county, turn out an abundance of 

 _'>od lime for ordinary building purposes as need desired, be The 

 sub-cry staliue layers of the Galena are well adapted for lime production, 

 and are much used for that purpose. On Pine creek, timber is abun- 

 dant ; stone from both the.se divisions is easily obtained, and of good 

 quality ; and lime can be made in any desired quantity. 



