GEOLOGY AND PALEONTOLOGY. 205 
deposits have been described in detail by the writer, forming volume V of the 
University Geological Survey reports. 
The first deposits of gypsum rock worked in the state were in the northern 
area, where, in 1872, at Blue Rapids, the Coon brothers built a frame shed on 
the Blue river and commenced the manufacture of plaster of Paris in a five-bar- 
rel kettle heated by a stove. Prosperity seems to have attended their work, for 
three years later they built a stone mill on the west bank of the river, using the 
water-power, probably the best in the state, for grinding. This mill, though no 
longer in use, is still standing, a monument to the opening of a great Kansas in- 
dustry. The mills in this area and one in the central area use the massive white 
gypsum rock, while the others in the central area use the loose gypsum earth, 
which is known as agatite, aluminite, and the like. This earthy variety was 
worked at Gypsum City, Rhodes, and Dillon, and is now used at Burns, Marion 
county, Mulvane in Sumner, Springvale in Barber, and Longford, Clay county. 
The Medicine Lodge area, with its continuation southward into Oklahoma and 
Texas, forms one of the largest gypsum deposits in the United States. It is ~ 
traversed by the Santa Fe railroad, and there are only two small mills located 
there at the present time. Near the town of Medicine Lodge gypsum rock caps 
the hills as a layer twenty-five feet in thickness, protecting the underlying soft 
red clays and shales, thus causing a most rugged topography, often likened to the 
** Bad Lands” of the Northwest. 
The term ‘‘low, monotonous prairies of Kansas’’ has no application to the 
gypsum belt. When the setting sun reflects its light against the red shales 
crowned by the white gypsum rock, it forms a scene of beauty which attracts 
the attention of every traveler through that region. The cajfions, often 200 feet 
in depth, are dry during most of the year, but after a summer thunderstorm they 
are filled with a tumultous flood of sand-laden waters. 
In the Eastern states the gypsum rock is ground mainly for fertilizer, but in 
Kansas it is ground and burned into plaster of Paris for casts, molds, and white 
finish for walls. This plaster sets in a very few minutes; but it is possible, by 
adding certain mixtures, to retard the set four to six hours, and the resulting 
product is sold under the name of cement wall plaster. This forms a hard, firm 
wall, which dries rapidly and is nearly fire-proof. Some of the large buildings 
in Chicago and Kansas City have used 2000 and 2500 tons of Kansas plaster, 
and the demand is increasing each year as the advantages are recognized. 
CLAY. 
Even the dust under our feet has a value, especially if we are standing in cer- 
tain places in thestate. Earth, mud, or, tospeak more technically, clay, which has 
been properly fashioned, and has emerged from the flames, passes through the 
hands of the mason into stately architecture. The total value of clay products 
in the United States is about sixty million dollars, of which one-half represents 
building brick. This brick would make a walk ten feet in width around the en- 
tire globe. 
One of the clay industries which has made remarkable growth in the last few 
years is the manufacture of vitrified brick for street paving. This industry has 
become especially important in southeastern Kansas, at Pittsburg and the towns 
in the gas belt. There are now thirteen factories of paving and building brick — 
three at Iola, two at Chanute, and one in Humboldt, Cherryvale, Coffeyville, In- 
‘dependence, Neodesha, Pittsburg, Girard, and Columbus. Other large plants 
are found at Atchison, Lawrence, and Topeka. 
Common building brick were about the earliest clay products made. The 
necessary materials were wide-spread, and no great skill is required in their manu- 
