ADDENDA. 
SincE the report on gypsum was placed in type, a new industry has come to 
the notice of the writer. ; 
Four miles west of Sun City, in Barber county, and in the Medicine Lodge 
gypsum area, was located the mill of the Standard Cement Plaster Company. 
This mill was built on the north side of the Medicine Lodge river, overlooking 
one of the most beautiful valleys in the state. The mill was used for some time, 
and manufactured a good quality of white finish plaster, from the gypsum rock. 
The property finally became involved in court trials and was closed, as stated in 
the foregoing report. During the last few months the mill and ground have 
changed hands, and are now under the control of the Roman Cement Plaster 
Company, with offices at Kansas City, Mo. 
A geological section back of the mill shows twenty feet of solid gypsum rock, 
resting on a limestone floor. The solid rock is covered by four feet of snow white 
porous gypsum with a fibrous structure, the fibers being vertical. On account 
of the porous character of the rock, it is very light in weight, and is readily 
quarried. Over this gypsum is found from eight inches to five feet of red clay 
impregnated with gypsum, and the surface layers are filled with grass roots. 
Formerly this surface red material and altered gypsum were removed and only 
the solid rock used for plaster. 
When Mr. Jno. Bickel took charge of the plant for the Roman Cement Plaster 
Company, he conceived the idea of trying this surface gypsum and reached good 
results. At the present time these surface deposits are used, and they make a 
plaster with a natural red or terra cotta color which is attractive and popular. 
In a recent trip to this region, I find that material similar to that on top of 
the hills over the solid gypsum rock occurs also in the valleys, forming deposits 
which are about 30 or 40 feet thick over a considerable area. In many places 
the thickness of material whose value has not yet been determined would reach 
150 feet. 
In origin, these deposits are apparently quite different from the gypsum earth 
deposits farther north. They are not in low ground and springs of water are not 
‘connected with them; yet at the same time they have resulted from water action 
subsequent to the original deposition from the old seas, and they are recent sec- 
ondary deposits. 
The gypsum has weathered first into the fibrous blocks, and these have fur- 
ther changed to granular gypsum, associated with red clay which has washed or 
blown in from the adjacent hillsides. The result has been to form an earth de- 
posit filled with gypsum and organic matter, the latter producing a slower set 
and acting as a natural retarder. Under the microscope this material is beauti- 
fully crystalline, the crystals showing even under a low-power glass. 
