.nlw YOKK > i a i E Ml BEUM 



Stratum 3 was rejected because quite deficient in clay and 

 silica. 



Stratum 1 was characterized as a poor rock, which might be 

 i if necessary, but was not recommended, being deficient in 

 clay. 



turn 5 was marked as being a Blight improvement over 4, 



owing to the smaller amount of carbonates it contained, though 

 lient in clay. 



Stratum 6 was too rich in carbonates and too low in alumina, 

 or clay, to be used for hydraulic cement 



Stratum 7 was the most Bilicious of the series, though it con- 

 tained little clay. With care in burning it could be used, as the 

 silica present was in a fine state of division. It is, however, not 

 an entirely satisfactory rock. 



Stratum S proved a good stone for this quarry. 



Stratum 9, in both its light and dark forms, was, besides hav- 

 ing great lack of uniformity, too rich in carbonates and deficient 

 in insoluble matter. By itself this stratum would prove < poor 



one. 



ratum 10 was excellent and recommended for use. 



S atum 11 appeared at a glance to be insufficiently hydrate c 

 and was excluded. 



Of all these strata, for one or more reasons, only those num- 

 bered. 5, v . and 10, were considered fairly good rock if burned 

 by themselves. It was possible, however, to mix different strata 

 and thereby obtain a mixture of the proper quality. Xo. 7 w T as 



asequently included, and the cement so prepared analyzed as 

 follows: 



Loss on ignition 8. 29 



Uncombined Bilica 1G.3 



Combined Bilica 13.5 



Alumina and iron <»xid 11 .04 



Lime 33.36 



Magnesia 15.58 



Sulfuric acid 4 



Alkalis 1.5 



