100 University Geological Survey of Kansas. 
Plat of rx Calcining Kettle 
— Stale Sp'a/ — Loran Mack he Lilohpse hbon 
Fic. 19. Gypsum Calcining Kettle (in sections). 
space between. The kettle bottom is convex upward and made 
of steel five-eighths inch in thickness. Such a kettle will hold 
seven and one-half tons of ground rock or earth. The gypsum 
is constantly stirred on the bottom of the kettle by two revolv- 
