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R. T. BAKER. 



ture of the timber. I have thought of several, but the most 

 feasible seem to me to be (1) the attaining of a maximum 

 amount of strength with a minimum amount of weight by 

 the disposition of the fibres and breaks in the "rings" 

 required by the large quantity of foliage carried by the tree, 

 and (2) strength to resist river currents and tides. Further, 

 I believe, that each individual "ring" represents a year in 

 the age of the tree, and this is supported at least by 

 authenticated trees planted during the last six or seven 

 years, whilst evidences certainly favour the theory that 

 these trees grow to a great age. 



(3) The sine que non of the life of the tree is a shading of 

 the roots, consequently trees are often found overhanging 

 the water at an angle that would be dangerous to the life 

 of an ordinary tree, and yet this inclined stem, carrying a 

 great weight of foliage and branches for the shading of the 

 pneumatophores, flourishes. In some instances stems are 

 almost parallel with the mud or water, hence the necessity 

 for great strength in the timber. (Plate XL VI, fig. 20.) 



(4) Then, again, the great vitality of the tree is assured by 

 the collective structure of each "ring," and so whatever 

 accident may happen to a part of the tree, there is always 

 left sufficient independent material to carry on the work 

 of leaf formation to procure shade for the pneumatophores, 

 so essential to the life of the tree. 



If these are not the reasons for such phenomena of wood 

 structure and growth, then I am afraid it is a case of 

 knowledge without understanding. 



Note: — In the discussion which followed the reading of the 

 paper, Mr. J.Nangle, f.r.a.s., explained that this strong and 

 especially built timber failed in reaching the testing figures 

 of the "Ironbark," owing to want of interlocking fibres 

 between each "ring," there being nothing to prevent a 

 sliding of the surfaces. In the case of beams, architects 



