STRENGTH AND TESTING OP TIMBER 305 



small pieces of jarrah arid karri, which when green con- 

 tained 50 and 54 per cent, of moisture, contained at the 

 end of six months 34 per cent, and 38 per cent., and at the 

 end of three years 13 per cent, and 14 per cent., whilst 

 large pieces of the same timber about 12 inches by 12 inches 

 contained 39 per cent, and 43 per cent, respectively at the 

 end of one year, 28 per cent, and 31 per cent, at the end of 

 three years, and after six years they still contained 21 per 

 cent, and 22 per cent, of moisture ; this timber had been 

 stacked in the open and well ventilated. Red gum and 

 blackbutt, which when green contained 75 per cent, and 61 

 per cent, of moisture, contained, as one might expect, after 

 the periods of seasoning mentioned above, a yet larger 

 proportion of moisture than karri or jarrah. 1 



As showing the influence of moisture on the strength of 

 timber, in the Western Australian tests it is stated that 

 tests of karri "green" gave results 46 per cent, less than 

 karri " dry " in end compression, yate gave 43 per cent., 

 blackbutt 40 per cent., tuart 35 per cent., jarrah 31 per 

 cent., red gum 29 per cent., York gum and wandoo 23 per 

 cent., and Morrell 22 per cent, below the strengths in end 

 compression of the same timbers which contained only 

 12 per cent, of moisture, which were, that is to say, perfectly 

 seasoned ; this being the standard of moisture adopted 

 for all the Western Australian tests, as well as for most of 

 those of the United States. 



In cross-bending tests for beams of Australian timber 

 25 square inches in section, the percentage of reduction in 

 strength between green timber and seasoned timber varied 

 from a maximum in the case of karri and tuart of 33 per 

 cent, to a minimum of 14 per cent, for wandoo. 1 In tests 



1 " The Physical Characteristics of the Hardwoods of Western 

 Australia," 1906. 



T. X 



