184 NOTES ON HYDRAULIC LIME AND CEMENT. — MASON. 



The sulphur existed in the form of iron pyrites which, wlien 

 burned in the oxidizinor atmosphere of the muffle, was converted 

 into sulphate of lime and peroxide of iron. 



It wall be noticed that the analyses show the deposit to be 

 very homogeneous, and further, that the burnt stone has an 

 analysis very similar to Portland cement with 50/^ of added 

 lime. 



Pats were made with varying proportions of quartz sand 

 which set rapidly in a moist atmosphere and hardened under 

 water. 



Some of the lime was hydrated and mixed witli twice its 

 weight of quartz sand, allowed to set for two days in a moist 

 atmosphere, then two months under water, then one month dry, 

 when i gave a tensile breaking strength of 140 lbs. per cubic 

 inch. 



A briquette made from the samples taken of the quarried 

 stone, burned, ground and mixed with twice its weight of gold 

 ore tailings, was placed, mould and all, immediately in water 

 for two months, then placed on the window-sill for twelve 

 months, and on breaking, it gave a tensile breaking strength of 

 354 lbs. per cubic inch. 



Mr. Fennell, manager of the Would ham Cement Co., West 

 Thurrock, Essex, England, reported as follows on the adapt- 

 ability of this limestone from Barra Head for 'the manufacture 

 of Portland cement : 



The Wouldham Cement Comfany, 1900, Limited, 

 Lion Works, 

 Established 185?. West Thurrock, Essex. 



29th Jan., 1904. 



" I beg to state that I have thoroughly investigated the. 

 sample of stone recently sent me for examination, and report as 

 to its suitability as a material from which to produce Portland 

 cement. 



" I have fortunately had considerable experience with the 

 manufacture of high-class cement from materials practically 



