10 ADDRESS BY THE PRESIDENT, NOVEMBER 3, 1875. 



and its defects ; the mode of desiccation and the quantity of water 

 existing in wood at different seasons ; the felling of timber and 

 the machinery to be used in its manipulation. 



The attention of our colonies also has been directed, of late years, 

 to the conservation of forests and the cultivation of trees fitted for 

 various economical purposes. I would especially allude to reports 

 on the durability of New Zealand timber in constructive work, 

 etc., recently published in that colony.* One of these is by Mr 

 T. Kirk, who points out the differences observed in the durability 

 of timber in different localities, arising chiefly from the following 

 causes : — 



1st. Trees having been felled during the growing season. 



I'd. Timber having been used immediately after being felled. 



3d. Trees having been felled before the heart-wood was suf- 

 ficiently matured. 



4th. The use of defective timber, whether shaky, worm-eaten, 

 or soft, from having been grown in unsuitable situations. 



5 th. Defective workmanship. No care having been taken to 

 exclude rain from impei-fect joints, exposed hewn beams left with 

 a concave upper surface, so as to retain rain, etc. 



6th. The application of paint and tar, etc., to the surface when 

 the timber is in an unseasoned condition. 



Mr Kirk also states that it is important that timber for public 

 works should be selected in the forest by some competent person, 

 so that unsuitable timber, whether defective from having grown 

 in situations not naturally adapted for the particular kind required, 

 or from not having arrived at maturity, might be rejected at the 

 outset. The seasoning of timber also requires special attention. 

 Mr Kirk alludes to the various attempts made to increase the 

 durability of timber by the absorption of mineral solutions. 



Mr Kirk has given a list of the more important trees in Australia, 

 with their qualities. A report has also been given by Mr J. M. 

 Balfour, engineer at Dunedin, on the strength of the New Zealand 

 woods, and by Captain E. W. Ward on their capability of bearing 

 pressure. 



In Vol. VII. of the Transactions of the New Zealand Institu- 

 tion, edited by Dr Hector, issued July 1875, there is a valuable 

 paper on Forest Culture by Mr F. C. Firth. In this article the 

 author speaks of the effects of forests on the landscape, as a shelter 

 for birds which devour insects, as well as for timber and for 

 * See Article in Edinburgh Review for October 1875. 



