Sioux City Academy of Science and Letters. 183 
handled or transported without great loss, except when 
freshly mined, and then the high percentage of water 
that must be freighted would not prove economical. 
If it could be satisfactorily delivered in Sioux City 
and sold at an advantageous price it might find extensive 
use as a steam coal in the many factories, but for its 
economical combustion, especially constructed grates 
would be necessary. This would be a handicap to it in 
its competition with the coals already in use. 
As for immediate fuel value in the restricted local 
area in which it is found, this depends largely upon the 
cost of production, for this region along the escarpment is 
still well wooded and thus provided with a cheap fuel 
supply. Therefore, from a business view point, at the 
present time the value of the lignite as a fuel is ex- 
tremely doubtful. 
Second, as to the extent of the lignite, the bed at the 
second horizon may be said to have a sufficient areal ex- 
tent, but its average thickness (22 inches) is not suffi- 
cient. Beds of good coal of this thickness are sometimes 
profitably worked, but in comparison with the lignites of 
Arkansas of 3 to 6 feet, with those of Texas of 4 to 6 feet 
—occasionally to over 15 feet, usually occurring as out- 
crops, and with those of Wyoming and North Dakota of 
over 20 feet, it is readily seen that the Nebraska lignite 
cannot well be considered in the same class. 
Third, the practicability of mining the lignite de- 
pends upon all the preceding features in conjunction with 
such local conditions as affect the actual mining opera- 
tions. In this region it is certain that only such beds as 
are above the heavy underground water horizon, or are 
above the level of the river flood plain so that they may 
be drained without pumping, can be worked at all. The 
nature of the roof over a bed of lignite is of the greatest 
importance. In this region, where lumber is compara- 
tively expensive, if timbering must be done to support 
the roof of a tunnel, that item itself would cost nearly as 
much as the value of the fuel removed. No satisfactory 
roof has yet been found over any of the Dakota County 
lignites. So, without going further, we have two fatal 
hindrances to practicable mining of the material where 
below the level of the flood plain: Heavy under- 
ground water, and no roof, and taking a few other sig- 
