o8 CEMENTS, LIMES, AND PLASTERS. 



demnation of the kettle process, for that process is undoubtedly far 

 superior in economy to its European progenitor, the oven process. 



FIG. 1 . 



Section on C-D, Rg. 1. 



Section on A-B, Fig. 2. 



FIG. 9. Construction and setting of gypsum-kettles. 

 (Trans. Am. Inst. Min. Engrs.) 



The following description of the process of calcining plaster in kettles 

 is abstracted, in large part, from an admirable paper * by Wilkinson. 

 In this process the gypsum is ground, and charged into cylindrical 



* Trans. Am. Inst. Mining Engineers, vol. 27, pp 514 et seq. 



