C.—3,

extractives. A specific-gravity survey and cordwood volumetric study are also in progress. Close co-operation is maintained with North American and Australian pulp and paper authorities and with firms having experience in the manufacture of pulp and paper products from pine pulp woods. 91. The production of charcoal for producer-gas purposes has passed through stages of rapid development and research to the present phase, which may be described as unavoidably static. Soon after the outbreak of war a Substitute Fuel Committee was set up to investigate alternatives to imported liquid fuel. Attention was immediately focused on charcoal and coal as the obvious materials, and in the absence of an established charcoal-burning industry in the Dominion, the Forest Service was instructed by the Ministry of Supply to provide sufficient charcoal for experimental uses, and to be in a position to meet substantial requirements in the event of sudden demands arising from a major curtailment of liquid fuel. Consideration was given to and research carried out on various methods of burning, including the beehive and pit methods. The concensus of local and overseas opinion was, however, in favoiir of the portable steel kiln, nineteen of which have been manufactured by the Railway workshops from specifications recommended by Australian and British Government authorities. Owing to the scattered distribution of potentially-suitable timbers for charcoalburning and the desirability of providing trained staff throughout the Dominion, units were established in the following localities : Puhipuhi (North Auckland), Rotorua, Taringamotu, and Erua (Main Trunk), Opouri (Nelson), Ngahere (West Coast), Darfield and Hanmer (Canterbury), and Fairfax (Southland). A total of 62 tons was manufactured from the following species : Rimu, matai, silver and hard beech, manuka, maire, tawa, rata, wattle, and several species of eucalypts. During the year 403 cords of wood were burnt for charcoal. The average yield of screened charcoal from one cord of wood was 500 lb., ranging from 350 lb. (rimu) to 800 lb. (maire). In comparison with high-density Australian timbers, these yields are low ; thus the New South Wales Forestry Commission reports that the average yield of screened charcoal from white box and red mahogany is 840 lb. and that of ironbark not less than 1,100 lb. per cord of wood. Such high yields cannot be obtained from the relatively low density timbers available for charcoal in New Zealand. Whilst a satisfactory grade of charcoal may be produced from all the woods tested, preference is naturally given by consumers to the denser charcoals such as maire and manuka. To ensure that only high-grade charcoal would be supplied to users of producergas vehicles, a charcoal specification was adopted, and private manufacturers of charcoal for sale were licensed under Supply Control Emergency Regulations 1939. Eleven companies or private individuals have been issued charcoal-burning licenses, but the quantity of charcoal sold by these licensees for producer-gas is believed to be very limited. Only 20 tons of Forest Service charcoal were sold during the current year. This poor demand has been due to three causes : (a) High price of charcoal, (b) adequate quantities of relatively low priced coal-fuel derivatives in the form of " Waikato char " and activated coke, and (c) availability of liquid fuel. A price of £15 per ton at main centres was fixed for State Forest charcoal, and subsequent experience has shown that a satisfactory grade of charcoal cannot be produced economically at a lower figure, owing to the high fuel-wood value of the timbers yielding the best charcoal, and high freight costs and wages. Although £15 per ton is equivalent to petrol at 2s. per gallon, petrol is still available and therefore preferred, and the output of coal-fuel derivatives at less than half the cost of charcoal is more than sufficient for the 1,000-odd producer-gas vehicles at present operating in the Dominion. Consequently, there is little inducement for users of producer-gas vehicles to adopt charcoal on even a small scale at the present time. Having, it was considered, achieved the primary objective—namely, the establishment of a charcoal organization which could be rapidly expanded to meet wartime eventualities—the continued lack of demand for the standard produce has finally necessitated curtailment of production. Until conditions alter, production will be largely limited to the Department's own requirements for its producer-gas-equipped vehicles. Stocks at the end of the period total 36 tons.

5—C. 3.

33