Y86 NEW YOEK STATE MUSEUM 



Analyses of fire hric7<: used in above tests 



Grecian American Silica Coke oven 



magnesite magnesite brick tiling 



SiO 2.16 3.10 94.07 69.89 



FeA+AlA 72 6.64 3.66 27.75 



CaO 4.20 3.76 1.39 .27 



MgO 93 . 03 86.50 .19 .17 





Specific 

 gravity 



Weight a 

 cubic toot 



Pounds 





3.54 



170.2 





3.44 



160.9 





2.56 



109.9 





2.54 



111.4 



The specific gravities and weight to the cubic foot were: 

 Specific gravity of fire brick 



Grecian 



American 



Coke oven tiling 

 Silica brick . . . . 



Glass pot clays 



Glass pots are made of a special grade of refractory clay, whose 

 necessary qualities are given below. While no glass pot clays are 

 found in this state, still many of the glass factories in l^Tew York 

 obtain the raw clays elsewhere and 'make the pots at their works. 

 Great care has to be exercised in their manufacture; not only must 

 the clay be thoroughly weathered, but the molded pot must be 

 free from the slightest cracks and exhibit a homogeneous structure 

 throughout. 



Requisite characters. A clay, in order to be suitable for the 

 manufacture of glass pots or blocks for tank furnaces should con- 

 form to the following requirements: 



1 Sufficient refractoriness to withstand the highest heat used 

 without changing form 



2 Great plasticity, such that the addition of 50'^-60^ of grog 

 will not affect it appreciably 



3 In burning, density at as low a temperature as possible 



A clay is generally considered sufficiently refractory for making 

 glass pots if its fusion point is the same as that of cone 30. It 



