24 KANSAS UNIVERSITY QUARTERLY. 
tured by Butterworth & Lowe, of Grand Rapids, Mich., and also 
by a Kansas company, the Ehrsam Machine Company, of Enter- 
prise. 
Figure 5. Gypsum Crusher, 
On the ground floor is placed the crusher and nipper. ‘The 
jaws of chilled iron, which have a back- 
ward and forward crushing motion, and it is operated by steam, or 
water power. Blocks, averaging fifty pounds weight, are thrown 
crusher has face plates or 
into this machine and crushed into pieces about the size of a man’s 
hand. These small masses drop from the crusher into the cracker, 
which is set in the floor just under the crusher. This machine, , 
with its interior revolving shaft, acts somewhat like a coffee mill 
and further crushes the gypsum into fragments of the size of small 
gravel which fall into buckets of a chain elevator, whereby it 1s 
raised to a bin on the second floor. From this bin the gypsum 
particles pass through a spout into an ordinary buhr mill where it 
is ground into flour. From the buhrs it passes into another chain 
elevator and is carried to the top of the second story into the stor- 
age bin, located just over the kettle. It is then run slowly into the 
calcining kettle, taking about one hour to fill it to a depth of five 
feet. The average kettle is eight feet in diameter and six to eight 
feet deep, surrounded by a wall of stone nearly four feet thick. 
