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THE STRENGTH OF SOUTH AUSTRALIAN TIMBERS. 



By Professor R. W. Chapman, B.A., B.C.E. 



[Read October 6, 1908.] 



The only previously recorded tests upon the strength of 

 South Australian timbers are some carried out by Professor 

 Warren at the University of Sydney, and chronicled in his 

 book on ■"xlustralian Timbers," published in 1892. These 

 tests were on specimens of Sugar Gum, Blue Gum, Box, and 

 Red Gum, supplied by the South Australian Conservator of 

 Forests. Although unfortunately we have not in this State 

 timber for export, it is very desirable that we should have 

 a knowledge of the properties of the timbers indigenous to 

 the country, and during the year some 200 tests upon the 

 mechanical strength of South Australian timbers have been 

 made at the University on specimens supplied by Mr. Gill, 

 Conservator of Forests. The following timbers are repre- 

 sented : — 



Botanical Name. Colloquial Xanie. 



Eucalyptus rostrata Red Gum 



,, fasciculosa Pink Gum 



,, ohliqua Stringy Bark, Messmate 



,, vim/nialis Manna Gum, "White Gum 



,, leucoxylon Blue Gum 



,, ruhida White Gum, Candle Bark 



,, hemi'phlouf Box Gum 



,, odoruta Peppermint Gum 



,, camhagei Bastard Box 



,, capitulata Stringy Bark, Messmate 



corynacalyx Sugar Gum 

 Pinus insignis 



All of these are indigenous to South Australia, with the 

 exception of Pin us insignis. 



Most of the timber came either from Kuitpo or Wirra- 

 bara, and was sent in j^ieces about 7 ft. long and 6 in. by 

 4 in. The greater part of it came in a fairly green state in 

 July, 1907. A few tests were made soon after its arrival, 

 but most of it was stacked in the laboratory and no further 

 experiments made until February this year. As the summer 

 was hot and dry the timber, especially small pieces cut ready 

 for testing, became well dried by the time the strength tests 

 were made. The timber contained a percentage of moisture 

 ("estimated on the weight of the dry wood) ranging from 20 



