248 



The Want of a Uniform System 



regard to transverse strength ; the most interesting point in 

 which is the difference between the results for ironbark as 

 found by the Engineer-in-chief of N.S.W. and the Railway- 

 bridge Commission on the one hand with 12 in. x 12 in. 

 beams, and Fowkes, Laslett, Tredgold, and Sydney Mint 

 on the other hand, with pieces whose dimensions were 

 2 in. X 2 in.: — 



Transverse Strength. 



Timber. 



Scantling, 



Mod. of 

 Kupture. 



Authority. 



Memel ) 

 Deal / 



9" X 6" X 17' 



I" X I" X 21' 



4,300 

 9,810 



I Tredgold 



Baltic ) 

 Fir / 



12" X 9" X 17' 

 3" X 3" X 4' 



3,200 

 10,400 



I Tredgold 



Red Gum 



10i"x7" ) 14,3. 

 2" X 2" X 2' 



8,800 

 11,700 



Vict. Rly. Dept. 

 Mueller 



British 

 Oak 



8-57" X 8-57" \ . 

 7-50" X 7-50" -^ 

 6-43" X 6-43" W 

 5-35" X 5-35" -^ 

 4-28" X 4-28" J ^ 

 2" X 2" X 6' 



9,130 

 9,280 

 8,680 

 9,530 

 9,550 

 10,800 



VBarlow 

 Laslett ' 



Ironbark, 



N.S.W. 



12" X 12" X 26' 

 12" X 12" X29-6' 

 2" X 2" X 4' 

 2" X 2" X 1' 

 2" X 2" X 1' 

 2" X 2" X 1' 



13,953 

 12,222 



18,000 

 18,000 

 22,000 

 24,100 



Engr.chf.KS.W. 

 Rly. Bdgs.Comn. 

 Sydney Mint 

 Fowkes 

 Laslett 

 Tredgold 



Resistance to crushing. — Here comparisons are impos- 

 sible. Barlow considered that the strength increased in a 

 higher ratio than that of the area, whilst Tredgold took the 



