W. H. VON STREERUWITZ-NON-METALLIC MINERALS OF TEXAS. 99 
a failure; for instance, the tests carried on in some of the cotton com¬ 
presses in Houston, 1887. I was present at these experiments from the 
beginning to the end. I studied carefully and noted the conditions and 
results, and it was admitted by the engineers and firemen (with whom 
the decision rested) that the heating power of the lignites from the banks 
of the Brazos near Calvert was a little more than half of the heating power 
of the bituminous coal generally, used under the boilers of these com¬ 
presses. This experiment was carried on on a large scale; it covered 
fully three days, and it was not a failure, but a full success for the fol¬ 
lowing reasons: The quantity was estimated by the volume and not by 
weight; the lignite was taken from near the river bank, where it had 
been exposed to leaching by the frequent rises in the river, and conse¬ 
quently had deteriorated; and last, but not least, it was burned on grates 
and in furnaces constructed for the use of bituminous coal, and in the 
flour mill test in a furnace built for wood firing. Or in other words, the 
lignites were tested under the worst conditions for the development of 
their heating power. I am positive that Texas lignites of average good 
quality, in furnaces built for this kind of fuel, can and will develop from 
two-thirds to four-fifths the heating effect of Pittsburg and Indian Terri¬ 
tory coal. 
Engineers and firemen may object to the brown coal, because it re¬ 
quires more shoveling and greater care to keep up the fire; but as hinted 
above, this objection will be lessened if the furnaces will be adapted to 
the fuel, instead of expecting that the fuel will adapt itself to the grate 
and furnace. 
When I said the greater part of the Tertiary belt of Texas is underlaid 
by brown coal, I did not intend to say that all this brown coal is avail¬ 
able. Local conditions require the same consideration in coal mining as 
in mining in general. To go into details on this subject would require 
more time than the present session of the Academy would or could allow. 
I had to be somewhat explicit in speaking of this subject in order to 
meet and refute beforehand the objection, that the want of suitable fuel 
would prevent the utilization of other valuable minerals. 
We find in Texas fire clays which favorably compare with the world 
renowned Stourbridge clay and the clays of Alt Almenrode. 
The experiments which I made in 1878 in behalf of Mr. Dillon with 
the fire clays of Limestone county, resulted in a fire brick resisting 
changes of temperature better than the Mt. Salvage brick and the im¬ 
ported English fire brick. Expansion and contraction were practically 
nothing, and their resistance to fusion equal to that of the best in the 
market. I formed by hand, of the same clay, a crucible, and fused in 
the same cast iron without destroying the crucible. Fire clays of equal 
quality are found in many localities together with the lignites in Texas. 
