468 CEMENTS, LIMES, AND PLASTERS. 



The writer has seen the Williams mill in operation at a number 



of Portland-cement plants, working on various raw materials and also 



on cement clinker. Its results when operating on shales, slates or ihin 



bedded slaty limestone are remarkably good, and the machine appears 



to be particularly well adapted for such materials. 



References on crushing machinery. The following books and 



papers contain matter of interest in this connection, Richard's work 



being, of course, by far the most important: 



Blake, W. P. The Blake stone and ore-breaker; its invention, forms and 

 modifications. Trans. Amer. Inst. Mining Engrs., vol. 33, pp. 988- 

 1031. 1903. 



Fischer, H. The operator of a tube mill. Engineering and Mining Journal, 

 Nov. 17, 1904, pp. 791-793. 



Fraser, G. H. Recent results obtained with the Kent mill as a fine grinder. 

 Cement, vol. 6, pp. 74-79. May, 1905. 



Hutchinson, W. S. The plotting of sizing tests. Transactions Amer. Inst. 

 Mining Engineers, 1904. 



Lesley, R. W. The manufacture of cement. Trans. Am. Soc. C. E., vol. 

 LIV, part B, pp. 89-130. 1905. 



Richards, R. H. Ore Dressing. 2 vols, 8vo, pp. 1236. 1903. 



Schwerin, M. Notes on some regrinding machines. Engineering and Min- 

 ing Journal, Mch. 10, 1904, pp. 403-404. 



Anon. The pebble tube mill in metallurgy. Electrochemical and Metal- 

 lurgical Industry, vol. 3, pp. 41-42. Jan., 1905. 



