H.—25

6

of the heart-wood. lam indebted to Mr. W. N. Blair, of Dunedin, for having cleared up any doubts I entertained of this, by showing me the fruit of what he considered the true black pine, which is clearly Podocarpus spicata: the tree with solitary fruit being the miro (P. ferruginea). In Dunedin I saw largo house blocks taken up which were perfectly sound after having been down upwards of fifteen years: weather-boards and flooring were good after having been in use twenty-five years —the weatherboards fully equal to totara and kauri. Several piles in the old jetty at Dunedin are sound after having been in use nineteen years. At Invercargill, two or three piles of a bridge near the railway station were drawn after being down nearly twelve years, and found perfectly sound throughout. In a situation in which the piles are exposed to teredines, at Port Chalmers, one or two specimens were much perforated, but sound above, after being in use thirteen years. Bridges in various parts of the colony afford similar proof of its durability, alike as regards piles, stringers, and braces; but it has been far more extensively used in the South than in the North, partly on account of its greater abundance in the former and the comparative rarity of totara. Used for tramway sleepers at the Taupiri Coal Mines, good results were obtained. Sleepers, in use for nine years were perfectly sound, with the exception of the sap. Although it has been somewhat brought into disrepute by the substitution of miro for it in several localities, there can be no doubt that it is one of the most durable timbers in the colony. For sleepers, piles, &c, it will probably rank next in value to Puriri, tho most durable of all New Zealand timbers. I was much struck with the remarkably durable appearance of a large quantity of new black pine sleepers laid near the Chain-Hill Tunnel, Dunedin, and have no doubt they will be found superior to totara, kauri, and black birch, all of which are in use on the same line of railway. 6. Mieo, also called Black Pine in Otago. — (Podocarpus ferruginea) Of similar distribution to the last, which it closely resembles. It is easily distinguished when in fruit, as the fruit is solitary instead of spicate. The cross section of the timber shows the heart-wood star-shaped and irregular. Much disappointment has arisen from the common names matai and black pine having been erroneously applied to the miro, which, under ordinary circumstances, is not a durable timber. It appears, however, to be specially adapted for use in situations where it is partially exposed to the influence of sea water, and under these circumstances exhibits greater durability. A most instructive lesson on the durability of timber under different circumstances, is afforded by an examination of the piling constructed for the protection of. the railway embankment at the Bluff Harbour. This protective work extends, with short intervals, for several miles, and is composed of two rows of piling, the outer row being driven strictly within high water-mark and about 8 or 9 feet above the ground level; the inner row is driven into the embankment about Bor 10 feet behind the outer row, and about 3 feet above the ground level. The two rows are connected by rimu scantlings, which are roughly let into the piles and secured by spikes, the front row being covered, to the height of 5 or 6 feet, with rimu boarding, and the space between the two rows of piles for the most part left open. Many of the piles in both rows are miro, but a most remarkable difference is shown in the durability of those in the front row, which are exposed to the influence of sea water, and those in the back row, which are not. Not a single miro pile in the back row is in a sound condition —many of them can be easily kicked to pieces. In the front row, not a single pile is unsound, and the bark and sap-wood, in many instances, appear as fresh as when the trees were cut. Mr. Hawkins, Inspector of Permanent Way, informed me they had been driven ten years. I have been unable to find another instance in which the miro has exhibited equal durability in exposed circumstances. Used as piles for fresh-water bridges, it has decayed in less than seven years. 7. Tanekaha. (Phyllocladus trichomanoides.) A straight, handsome tree, 50 to 60 feet high, trunk rarely exceeding 3 feet in diameter. Common in hilly districts in the North Island, and more abundant in the Province of Auckland. The timber is white, dense, and heavy, closely resembling the best crown memel of Europe in everything but size. No experiments have been made to test its strength and elasticity, but it appears to be one of the strongest timbers in the colony, and one of the most durable, although, from its occurring most freely in the kauri district, it has scarcely been utilized at present. On the Thames Gold Field it is greatly valued for mine props, struts, and caps, which were perfectly sound after having been in use six years. Tramway sleepers were in the same good condition after having been laid five years. Used as round piles, it was sound, fresh, and untouched by teredines after being driven four years. Squared land piles in the Waikato Coal Mines showed the sappy edges decayed after having been driven nine years, but the heart in excellent condition. Totara from small trees, and large manuka, under exactly the same conditions, were badly decayed at ground level: miro and rimu were worthless. A quantity of railway sleepers, split at the commencement of the Auckland and Drury Eailway, in 1865, were stacked in Mr. Hay's paddocks at Papakura, where, in consequence of the discontinuance of the works, they remained untouched until 1873, when the stacks were taken down. The bottom layer of one of the stacks was composed of tanekaha sleepers, which had been laid directly on the grass, and although in this trying position for about eight years, had remained perfectly sound, with the exception of some trivial patches of sap, which had decayed without affecting the heart-wood. I have been informed that tanekaha has been used for water-tanks at the Bay of Islands, and has remained sound after being eighteen years in use. This timber appears specially adapted for railway sleepers and for road planking for bridges. As it occurs in several places near the line of the Auckland and Waikato Eailway, its durability may be readily tested.