COMMUNICATIONS. 357 



lEON. 



The most important deposit of iron in this State, is found in 

 Dodge and Washington counties; principally known from its 

 exposure upon the surface of Iron Eidge, where it is now being 

 worked by the Northwestern Iron Company. 



This deposit consists of a bed of ore, included between regu- 

 larly stratified rocks, and extending over a considerable space. 

 At Iron Eidge it presents an unbroken outcrop for nearly a 

 mile. It occurs again at Hartford in Washington county, some 

 14 miles distant, but the intervening space is covered with heavy 

 drift, and we have no means of ascertaining whether it is a con- 

 tinuous stratum or otherwise. Its thickness varies from 7 to 20 

 feet, being greatest at Iron Eidge, and thinning out towards the 

 east. Without attempting to state accurately its dimensions, in 

 the present state of our knowledge, we are certainly safe in re- 

 garding it as practically inexhaustible. 



The ore bed, in its original state, is regularly stratified, and 

 divides by partial scattering into thin layers, which are made 

 up of small nodules or kidney shaped particles, resembling flax- 

 seed in size, color and greasy feeling. 



By long exposure, the outer beds have been completely de- 

 composed into these constituent particles, forming a soft and 

 easily excavated mass, known as seed ore, at the furnace. The 

 ore, in its original state, is known as rock ore. Occasional con- 

 cretions of compact hemetite occurs, scattered through both the 

 rock and seed varieties, evidently resulting from a recomposition 

 of the ordinary forms of the ore. The limestones adjoining the 

 ore, are frequently desolved by it, and crystals of hemetite and 

 specular iron are found in grades and fissures, but these expo 

 sures rarely extend beyond a few inches. 



Chemical Gom'position of the Ore. 



The following analysis will present the chemical constituents 

 of this ore : 



