Notes on the Geology of the Southwest. — Hill. 369 
with Dr. Cooper Curtice of the U. S. G-eological Survey, and veri- 
fied my observations by collecting a large and abundant fauna of 
typical Carboniferous forms at both localities, which are one and 
the same stratum, including Zaphrentis, Productus, and other 
typical Carboniferous species, all of which are on deposit in the 
Smithsonian Institution, where they can be seen. I shall be glad to 
furnish specimens of this fauna to all interested. Dr. Comstock 
also kindly remarks that I "hit" upon the age of the adjacent 
Burnet granite. Possessing the average amount of that humanity 
which is liable to err, especially in the stud}- of those geologic 
specialties which are be} T ond my own narrow branch of the science, 
I must confess that the age of the Burnet granite is the only "hit" 
in the above mentioned paper wherein I missed, for I have since 
found that the overlying and contacting Potsdam sandstone is 
largely composed of this granite's debris, quartz, and feldspar and 
that Walcott's original determination of the pre-Potsdam age was 
correct. 
JEolian deposits of Eddy county, New Mexico. The main 
western escarpment of the great mesa of the Llano Estacado is 
about Mty miles east of the present channel of the Pecos river, 
which has cut down through the fine clays and sands of the Red 
beds ( Permo-Trias ) and is blowing at this contact with the hard 
Permian limestones. The prevalent winds in this extremely arid 
region are from the west, and the fine sandy debris of the Bed 
beds is blown eastward until its course is obstructed by the western 
escarpment of the Llano Estacado, where it forms a long strip of 
almost impassable sands 100 miles long by ten miles wide. So 
excessive is this wind erosion in the New Mexican portion of the 
Pecos valley, that sand storms are very prevalent, and I saw 
nearly ten bushels of fine sand swept from a large veranda as the 
accumulation of twenty-four hours time. 
Possible Uses of Lignite. — The manufacture of the wood}', 
fibrous lignites of the Eocene beds of Texas into briquettes is the 
subject of great discussion in Texas at present. That this cannot 
be done profitably owing to cost of manipulation has been proven 
by the extensive experiments of the Houston and Texas Central 
railway company. But there are other uses to which this in- 
exhaustible mass of fuel can be put. Burned in situ the energ}' 
can be converted into electrical force and transmitted cheaply for 
industrial use. "Artificial natural gas," or water gas can also be 
26 
