C.—s,

In addition to creosote, particular attention has been paid to another group of non-aqueous preservatives —namely, those carried in a volatile oil solvent, the chief characteristics of which are (a) Freedom from objectionable odour. (b) Quick drying after treatment. (c) Do not cause swelling or distortion of timber. (d) No detrimental effect on subsequent painting. This Service strongly advocates the wider use of exotic pine timber in housing construction, and the volatile oil preservatives referred to above are the most suitable for the treatment of members particularly susceptible to decay, such as window-sashes. Of this group of preservatives, pentachlorphenol is considered by this Service to be the most promising on the scores of toxicity, permanency, and cost; research on the suitability of fuel oils available in New Zealand as solvents for this preservative have shown satisfactory results, and tests on a semi-commercial scale have been initiated. The increasing use of insignis pine for weatherboarding has led to an investigation into the most suitable priming paints for this and similar timbers which have a tendency to cause flaking of paint from the knots and resinous summerwood bands. Overseas research indicates that the most satisfactory priming pigment for this special purpose is aluminium in long-oil spar varnish if used on dry timber, but a series of exposure tests are being conducted under field conditions to measure the serviceabilities of this and various other promising priming paints under New Zealand conditions. Standard toxicity tests of all the creosotes of different origin and manufacture to be used by this Service have been carried out, and it is gratifying to record that their toxicities compare very favourably with those of standard American creosotes. (d) Grading, <&c. With the steady increase in production and the wider use of exotic softwoods a need for definite grading rules on which they can be sold has become apparent. That the species will definitely be suitable for far wider fields of utilization than they at present enjoy is beyond doubt to those familiar with timber utilization in Europe and North America, but progress in this direction will be limited until grading rules rigidly specifying the limitation of defects are available. To remedy this deficiency a wide range of mill and utilization studies is being undertaken as a major feature of the State Forest Service's utilization programme during the current year. Similar studies aimed at the standardization of sizes and profiles of the commonest finishing timbers such as flooring, weatherboarding, and match-lining are in progress. CHAPTER IV.—THE TIMBER TRADE. I. General. It is reported by the Government Statistician that the production of roughsawn timber for the year ended 31st March, 1938, was 323,000,000 board feet, as compared with a predicted cut of 330,000,000 board feet. It is 5-| per cent, above that for the previous year, and constitutes the highest recorded annual cut since 1925-26. As judged by the undiminished activity in building construction during the year under review and the timber traffic over the New Zealand railways it is estimated that timber-production for the year ended 31st March, 1939, will be approximately 335,000,000 board feet. For the current year ending 31st March, 1940, there is every indication that production will be still higher. The Government has found that the present rate of house-construction is insufficient to meet the current demands for dwellings and is making every endeavour to accelerate its housing programme, whilst a revival of private building is reflected by the doubling of State Advances loans over the last two years. The cut for the year ended 31st March, 1940, is expected to approach 345,000,000 board feet, which approaches closely the peak reported production of 353,000,000 board feet in 1925-26.

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