40 Transactions. — Miscellaneous. 



ground-floor without a space left for ventilation. Nearly if not 

 all the ground-floors on the east side of Lower Queen-street are 

 decaying with "dry rot." I have known 12 in. x 3 in. all heart 

 kauri joists quite rotten in twelve years ; the joists will break off 

 in pieces from six inches to two or three feet long, and will be found 

 flat on the ground, with square ends, the timber always breaking 

 at right angles to the fibre of the wood. The kauri is also 

 destroyed by a small grub, similar in some respects to the grub 

 in the kahikatea, but with this difference : the grub in the 

 kahikatea always bores with the fibre of the wood ; the grub in 

 the kauri will bore in any direction. I have here a sample of 

 kauri bored with this grub. The sap-wood will be attacked first ; 

 but if found in a building, it will soon go right through, heart 

 and sap falling a prey to it. 



One great reason for kauri and other timber decaying is the 

 constant use of young and unmatured timber. A mature kauri 

 will be at least five feet diameter, showing well defined sap-wood 

 of not more than three to four inches. Now, a large quantity of 

 logs cut up in Auckland will not measure more than 2 feet 6 inches 

 to 3 feet in diameter : this size log will have nine inches of 

 sap-wood, leaving on a log 2 feet 6 inches only 12 inches of heart, 

 and that soft and white. Next to using young timber is the constant 

 use of unseasoned timber, and the practice of our mill-owners 

 cutting down trees all the year round, and full of sap. I 

 consider the trees should be " barked " at least six months 

 before being fallen ; the barking, of course, simply means cutting 

 out a ring of bark, say four or six inches in width, close to the 

 ground. Another plan, adopted in America, is to bore two holes 

 right through the trunk, crossing each other in the middle of the 

 tree ; either or both are inexpensive operations, and should be 

 tried by the mill-owners. As to the time of year for falling our 

 New Zealand timbers, I consider, if barked or bored as I 

 suggest, it would not matter a great deal. It will be seen at 

 once that if we get rid of the sap or gum before falling we have 

 overcome half the difficulty (if not more) experienced in season- 

 ing. Hence the failure of artificial seasoning by the hot 

 chamber, used a short time ago by some of the mills, the hot 

 chamber simply baking the outside, leaving the sap and gum 

 inside the plank. It is a fact known to all carpenters that kauri 

 will season better in the rain and wind of winter than the hot 

 sun of summer. Most of us know the effect of new kauri shingles 

 on a tank of water : the gum and sap is washed out to such 

 an extent by the rain, that the first water off the roof is like weak 

 turpentine, and dark in colour. Then we have another cause of 

 decay, consequent upon using unseasoned timber, that is the in- 

 judicious use of tar. It is right to tar a well-seasoned piece of 

 timber, but utter folly to tar green timber, and all round, as we 

 see repeatedly done in our buildings and wharves. I have known 



