18S NOTES ON HYDRAULIC LIME AND CEMENT. — MASON; 



blowing. The last named test is most searching in character, 

 and is one which only a high class Portland cement would be 

 capable of withstanding. 



" Pats of the cement which were guaged and placed under 

 old water a few minutes after guaging, set hard and showed 

 no sign of cracking or buckling. 



" Accompanying this are samples of the ground limestone, 

 ground clay, the raw material (admixture of stone and clay), 

 cement clinker, and the finished cement. In addition are pats 

 winch have been subjected to the boiling water test, together 

 with the broken bri(juettes and also the mould of cement which 

 has been subjected to the Le Chatelier test. 



" It may be borne in mind that in preparing small samples of 

 cement, the maximum results are never realized, and cement 

 made on a large scale with this material would give much 

 higher results under test. 



" In conclusion I beg to state that this limestone is one of the 



best possible materials from which to produce really high class 



Portland cement." 



(Sgd.) Wm. Fennell. 



I am inclined to think that there is a mistake in Mr. 

 Fennell's analysis of the stone. It will be observed that no 

 possible mixture of the limestone and clay of the analysis 

 given can produce a cement of the composition given by his 

 analysis. 



There can, however, be no possible doubt that given a suit- 

 able clay for mixing, this limestone is admirably suited for the 

 manufacture of Portland cement ; and further, that the burnt 

 stone by itself makes an excellent hydraulic lime. 



The writer is now experimenting with two clays and a soft 

 clay slate found in close proximity to the limestone for mixing 

 purposes, and he hopes at a future date to prepare a paper on 

 the cement industry at St. Peter's, Richmond County. 



