68 | University Geological Survey of Kansas. 
far as is known there is none lying below the deposit. It is 
whiter in color than any of the other deposits known in the 
state. Under the microscope it is found to be almost entirely 
composed of minute yet very perfect crystals of gypsum of uni- 
form size. ‘These crystals are more perfect in form than any 
others which Lave been examined from the gypsum earth beds. 
As no plaster has yet been made from this deposit it cannot 
be said whether or not this extra degree of purity will result in 
an extra plaster. Asis pointed out later under the discussion 
of the technology of the gypsum plasters, the plaster made 
from the rock gypsum is slightly different in character from 
that made from the gypsum earth deposits, this difference 
being due principally to the greater purity of the gypsum rock. 
If the gypsum earth material makes a plaster more desirabie 
in some respects than that made from the rock gypsum, it may 
be possible that a high degree of purity in the gypsum earth 
beds would result in the production of a plaster more nearly like 
that obtained from the rock gypsum. | 
A mill of two-kettle capacity has been erected, and began 
operation with one kettle early in December, 1898, with a pros- 
pect of starting the second kettle soon. This mill is erected at 
Burns, on the El Dorado branch of the Atchison, Topeka & 
Santa Fe railway. The mill is operated under the company 
name of ‘‘The Kansas Southern Cement Plaster Company.”’ 
MULVANE DEPOSIT. 
About two and a half miles northeast of Mulvane, just across 
the line in Sedgwick county, a large deposit of the gypsum 
earth has been discovered on the farm belonging to Mr. W. R. 
Stubbs. The material covers an unusually large area along a 
little stream which cuts through the bed of the deposit, expos- 
ing it along the banks, where in places it reaches a thickness of 
12 feet or more. It has been estimated that there is enough of 
the material here to produce nearly half a million tons of the 
manufactured plaster. The quality of the gypsum earth com- 
pares favorably with that found elsewhere, as may be seen by 
referring to the table of analyses. 
