80 G NEW YOKK STATE MUSEUM 



Insoluble : 1.88 



Sulfuric anliydrid . 'i'S 



Ferric oxid and alumina 2.03 



The composition of the limestone in Alvord's quarry is : 



Silica 1.6 



Alumina and ferric oxid .7 



Lime carbonate .97 



Magnesium carbonate 1.11 



This same quarry also contains several layers of cement rock^ 

 of which the following are analyses. 



Upper layer Lower layer 



Silica 10 . 97 10 . 95 



Alumina 4.46 5 . 32 



Ferric oxid 1 . 54 1.3 



Lime 27 . 51 30 . 92 



Magnesia 16.9 13 . 64 



Carbon dioxid 37 . 94 38.31 



The composition of the blue lime in the Splitrock quarry of the 

 Solvay CO. is as follows: 



Silica 5.35 



Alumina .56 



Ferric oxid .61 



Lime carbonate 85 . 41 



Magnesium carbonate 18.86 



I'he Upper Helderberg, in Onondaga is a light gray semicrystal- 

 line limestone, the layers being separated by partings of shale. 

 The rock is at times variable in its character and may at times 



