194 



E. T. BAKER AND J. N ANGLE. 



Effect of Heat on New South Wales Building Stones — continued. 



No. 



Rock Treated. 



Temp, of 



Furnace 



°C. 



Time in 

 Furnace 

 Minntes. 



How Treated and Remarks. 



22 



23 



24 



25 



26 



27 

 28 



29 



Tenterfield 

 Granite 



Nemingha 

 Marble 



Warialda 

 Marble 



Attunga 

 Marble 



Warialda 

 Marble 



Attunga 

 Marble 



Fernbrook 

 Marble 



544 



20 



542 

 719 



25 



25 



744 

 758 



808 

 802 



695 



35 



40 



10 

 10 



30 



Heated gradually and plunged 

 suddenly into cold water. 

 Almost unaffected, on close 

 examination several small 

 cracks could be seen to be 

 developed. 



Heated gradually and cooled 

 slowly in air. Calcination not 

 started and rock unaltered. 



This specimen was placed in the 

 hot furnace, but owing to 

 trouble with the furnace, the 

 temperature became much 

 reduced, but was afterwards 

 raised again. The specimen 

 on removal was plunged into 

 cold water, cracks appeared in 

 several places, but the calcin- 

 ation was only slight. Game 

 through the test fairly well. 



Heated gradually and cooled 

 in air. Specimen ruined. 



Heated gradually and cooled 

 in air. Specimen broken 

 into pieces. 



Placed in hot furnace. Cracked 

 slightly on removal. Plunged 

 into cold water, broke in two 

 pieces. Specimen ruined. 



Placed in hot furnace. Cracked 

 slightly on removal. Plunged 

 into cold water, badly cracked 

 in several places. Specimen 

 quite disfigured. 



The furnace was gradually 

 heated up to this temperature 

 when the specimen was taken 

 out and a spray of cold water 

 played upon it. The original 

 colour was quite destroyed 

 although the edges remained 

 intact. 



