REPORT OF THE STATE GEOLOGIST. XXXIX 



This area, so rich in soil and timber, is no less remarkable for the 

 value of its mineral contents, among which we may mention the iron 

 ores, lignite, petroleum, fire-clay, pottery-clay, glass-sand, and green - 

 sand marls. The iron ores are not confined to this division, and there- 

 fore will be discussed later. 



Lignite. — As has already been stated, the beds of lignite are numerous 

 and the quantity is beyond question fully adequate to all demands that 

 may be made upon it. The real value of this material as fuel is not at 

 all appreciated. Lignite, up to the present time, has been regarded as 

 of very little value. Two causes have been instrumental in creating 

 this impression : first, the quality it possesses of rapidly slacking and 

 crumbling when exposed to the air, and second (and perhaps this is the 

 principal cause), all who have attempted to use it have done so without 

 first studying its character and the best methods of burning it, and 

 they have in most cases endeavored to use it under the same conditions 

 which apply to a bituminous coal containing little water. While lig- 

 nite may not differ materially from bituminous coal in weight, its 

 physical properties are entirely different. This is due not only to the 

 amount of water contained in the lignite, amounting to from ten to 

 twenty per cent of its weight, but also to the fact that it is the product 

 of a different period of geologic time and that its original vegetable 

 growth was of somewhat different character from that from which 

 bituminous coals are formed, and it may be that the method of forma- 

 tion differed in some way in the two. Therefore, in any intelligent 

 effort to make it available for fuel, these considerations must be taken 

 into account, and proper allowances made for them. In Europe, where 

 fuel is scarcer than here, lignites of much poorer quality than our av- 

 erage deposits are successfully used, not only as fuel for domestic pur- 

 poses but also for smelting. 



The amount of sulphur contained in these lignites is very variable, 

 as is indeed the quality of the lignite itself. In most places we have a 

 good, clean lignite, almost if not entirely free from sulphur, but at 

 other places masses of sulphuret of iron are mingled through a carbon- 

 aceous mass. The different methods of rendering it a truly serviceable 

 and inexpensive fuel have been stated several times. The better 

 grades can be advantageously used near the mines for steam making 

 and household purposes, if properly constructed fire-boxes are used. 

 By crushing and mixing with asphaltum or coal tar pitch at 212 

 degrees Fahr., much of the contained moisture will be driven off, and 



