BY H. C. RICHARDS. 131 



Evidence of weathering is very pronounced on the 

 Queen Street front in jDlaces, and its use in the Treasury 

 buildings seems to have been unfortunate. The main 

 point which appears to have actuated the selection was a 

 desire to obtain a Avhite stone free from discoloiTration. 



Absorption tests by the Go\ernment Analyst of New 

 South Wales, in 1888, gave an average value of 4.8 per cent. 

 for three tests, while W. A. Dixon, of Sydney, got an 

 average result of 7 per cent, on two samples. 



The great variability in the cjuarries and in the stone 

 from the same quarry is very striking in the case of this 

 stone, and many thousands of feet were rejected as unsatis- 

 factory in the construction of the Treasury building. 



Yan Gan Sandstone. 



This brown sandstone is probably the be.st sandstone 

 in use in Queensland at present. It is quarried in close 

 proximity to the Yan Gan railway station, which is 172 

 miles from Brisbane, and 13 miles south-west from War- 

 wick. It belongs to the Walloon series of coal-measures 

 and there are available large quantities of stone. 



It is a fine-grained sandstone, much finer than most 

 of the other sandstones in the Warmck district. It has a 

 warm brown colour and shows very pronounced concentric 

 iron-staining at times. The brown colour is not quite as 

 warm as that of the Helidon stone. A microscopic 

 examination shows this stone to be an even, fine-grained 

 sandstone with an average grain-size of .20mm. The 

 particles are angular to subangular and the amount of 

 felspathic cementing material is less than in most of the 

 sandstones used. It is much the same in grain-size and 

 proportion of cement as the Calvert sandstone used in 

 Perkin's Brewery but is a much superior stone (see 

 microphotograph 3, plate VIII). 



The stone works well and takes a ver^- sharp arris. 

 Several c^uarries have been opened in the same localit}^ 

 and the j^resent main quarry has a very fine back in it. 

 Stones of considerable size can be obtained, as the beds, 

 which are fairly horizontal, are rather thick and while the 

 stone is well jointed the joints are far apart. Blocks of 



