207 



Warren, W. H. "Sand Blast Tests of New South Wales Timbers," Journ. 

 Roy. Soc. N.S.W., xliv, 620, 1910. 



Twelve of the timbers chosen for comparison were Eucalypts, viz. :— 



Blackbutt (E. pilularis). Red Mahogany (E. resinifera). 



Tallow-wood (E. microcorys). Grey Box (E. hemiphloia). 



Grey Gum (E. propinqua). Woollybutt (E. longijolia). 



Grey Ironbark (E. paniculata). Spotted Gum (E. maculata). 



Blue Gum (E. saligna). Jarrah (E. marginata). 



The first nine were from New South Wales, all coastal, mostly North Coast, the 

 remainder South Coast. The tenth was the well-known Western Australian timber. 



The apparatus is described and the method of conducting the experiments. 

 In addition to the tables of results, there are plates showing — 



(a) Specimens of the various timbers after testing in direction A, i.e., parallel 

 to the direction of the fibre. 



(b) Specimens of the various timbers after being tested in direction B, i.e., 

 perpendicular to direction of fibre and also perpendicular to annual rings. 



(c) Specimens of the various timbers after testing in direction C, i.e., perpendicular 

 to direction of the fibre, and tangential to the annual rings. 



Mr. R. H. Cambage, Joum. Roy. Soc. N.S.W., xlvii, 34 (1913), has the 

 following general notes in regard to the hardness of Eucalyptus timbers from a 

 geographical point of view, mainly as regards New South Wales : — 



Timbers may broadly be grouped under two heads, vi ; : — Texture and colour; the former of which 

 may be subdivided into hard and soft, and the latter into dark and pale. In arranging Eucalyptus 

 timbers into hard and soft groups it is found tha the hardest occur in the Interior where the conditions 

 are the most arid and the trees of slowest growth, though the hardest are not necessarily the strongest. 

 The second in degree of hardness are found on the Western Slopes, the third on the Coastal Area, and the 

 fourth or softest in the Mountain Region. The Coastal Area contains both hard and soft Eucalyptus 

 timbers, members of the Ironbark group, such as E. paniculata. siderophloia, and crebra. also E. hemiphloia 

 of the Box group being among the hardest. It might perhaps be expected that the decrease in hardness 

 would accord with the increase in rainfall, but although this progression applies so far as the Interior and 

 Western Slopes are concerned, it is in the division with the third highest rainfall and not the fourth, viz., 

 in the cold Mountain Region, where there are the least hardwoods. 



Now, under the peneplain conditions, long prior to the Kosciusko period, a greater similarity in 

 the texture of Eucalyptus limbers in South-Eastern Australia would undoubtedly have existed over at 

 least the Coastal, Mountain, and Western Slopes divisions, and it seems a fair inference that the great 

 uplift in that period is responsible for accentuating, even though an earlier and slighter uplift may have 

 helped to originate, some of the various differences in the textures of these timbers. 



Mr. R. T. Baker, in his " Hardwoods of Australia," at p. 2, has a qualitative 

 scale of hardness, viz. : — Very hard (E. crebra), hard (E. rostrata), moderately hard 

 (E. gigantea or delegatensis) (and E. marginata), which, however, does but show the 

 unsatisfactoriness of all such scales in the present state of our knowledge. 

 G 



