The Pamphlet Collection of Sir Robert Stout: Volume 64
This section of the Coniferæ comprises about 60 species that are scattered over all parts of the world except Europe and North America. Of this number Otago possesses five, four of which are timber trees, and one an Alpine shrub.
No. 2. Miro—Podocarpus ferruginea. Miro is common in all the forests of Otago that lie under an altitude of 1,000 feet, and occasionally in those above that level. It is generally found associated in the same bush with red pine. The tree grows to a height of from fifty to ninety feet, with a clear straight trunk twenty to fifty feet long, and eighteen inches to three feet in diameter, but the tallest trees are not always the thickest, particularly in dense forests. This timber, which is far inferior to black pine in point of durability, is so like it in many respects that they are frequently confounded. I shall therefore describe their leading points of resemblance and difference. Generally black pine is a heavier timber than miro, but this is scarcely a distinction, for a full grown tree on the one hand may be compared with a young one on the other. The scales on black pine bark are thicker, and the furrows deeper than those of miro. The foliage of black pine is flat like the English yew, and of a light green colour, shiny on the lower side. That of miro is roundish and erect, and of a deep dull green, which turns to rusty red on drying. Black pine has a cluster of from four to seven small dark berries, scarcely noticeable among the foliage; while miro has a conspicuous single berry like the dog rose or sweet briar, almost identical there with in size and shape, but of a redder colour. This berry has a strong odour of turpentine. Although black pine is sometimes marked in a decided manner, it has always a ground colour of clear yellowish-brown, but miro is blotched throughout, and the ground colour, which is light dirty red, varies every few inches. A horizontal section of the latter shows that the heart contains a considerable portion of dark-colored wood, which [runs in star-like points towards the circumference, hence the blotched appearance of the timber. The figure can be varied at pleasure by simply; changing the direction in which boards are cut. The annual rings and other markings in black pine are generally concentric. Consequently a great variety of figures cannot be obtained. Generally the wood of black pine is lighter and brighter in colour and easier worked than mho. The timber can also be distinguished when green by the taste and smell. These are strong and pungent in both cases, but there is a peculiarity in each easily recognised when once known. These particulars may seem too much detailed, but when we consider the disappointment and loss that have page 156 frequently resulted from the substitution of one timber for the other, their points of difference can scarcely be too well known. Miro is a fast growing tree, and the annual rings are tolerably distinct. A stump twenty-two inches diameter on Pine Hill gave the age at 160 years. There is frequently more sap than heart in the timber, and the distinction between the two qualities is not well marked, consequently it is not suitable for exposed work, even if durable. A log from a young miro on Pine Hill, twenty feet long eighteen inches diameter at the base, and twelve inches at the top, had an average of seven and a half inches of heart. At Catlin River the smaller trees are almost three-fourths sap, but the full grown ones have only from two to four inches.
Aged miro has usually a crack in the heart, but it is small and straight, so cannot be considered a serious defect. The timber is the strongest of the New Zealand pines, consequently is well adapted for beams in a dry well ventilated situation. As it does not shrink or warp to any inordinate extent, it is suited for ordinary house building, but being more difficult to work than red pine, the latter is preferred by carpenters. Miro is not durable in any exposed situation, except under water. It will perish in a few years if in contact with damp, and is very subject to the ravages of the large grub, which perforates the timber to the heart. I have seen bridge piles at Wallacetown a perfect mass of rottenness through the latter cause, but the portion below water level was sound to the bark. Mr. Kirk reports the same state of things at the railway protective works in Bluff Harbour, The outside piles exposed to the influence of sea water were perfectly sound, but those in the embankment a few feet further in were quite rotten. He attributes the preservation of the former to the action of salt water, but the example at Wallacetown would indicate the same result in any wet situation. Twelve-inch miro piles in the George-street jetty, Port Chalmers, erected in 1860, are eaten away to about four inches by the Limnoria but are otherwise in good preservation.
No. 3. Totara—Podocarpus totara. Totara, which is the best known and most easily recognized of our timber trees, is common in all the forests of the province up to an altitude of 1,000 feet. It is generally found mixed with black pine, but occasionally, as on Inch Clutha, forms an entire bush of itself. The supply of totara in the vicinity of Dunedin and Invercargill is getting scarce, but there is still a considerable quantity about the Clutha mouth, and the west coast supplies are still untouched.
The timber seems to grow well on any ordinary soil, but prefers rich alluvial flats. Ordinary sized trees attain to a height of from sixty to eighty feet, with a clear straight trunk from twenty to fifty feet long and three to five feet in diameter; occasional trees are found up to seven and page 157 eight feet, but these dimensions, though common in the North Island, are rare in Otago. Forty stumps recently examined on Inch Clutha range from three to four feet, with a few up to five; the thick trees are generally much shorter than those of medium diameter. The bark is of a light grey colour, thick, furrowed, and stringy; it was formerly used by the natives and old settlers in covering the walls and roofs of whares and huts.
Totara is a comparatively slow grower—a tree three feet six inches in diameter is estimated to be 550 years of age. Mr. Hay, of Auckland, found young trees to grow about twelve feet six inches in ten years; when fully established, they grow two feet in a season. Totara is one of the easiest: reared of our native trees. The tree has very little sap-wood, but is subject to decay in the heart, like cedar; it commences on Inch Clutha when three feet six inches in diameter, and increases with the growth beyond that. The timber is of a reddish colour, like pencil cedar, but varies considerably, according to its age and the soil in which it is grown; it is straight in the grain, easily wrought, and not given to warping, but brittle, and apt to shrink if not well seasoned. Totara is suited for fencing, railway sleepers, and piles, together with architectural and engineering purposes generally, except beams, for which, on account of weakness, it is not so well adapted as many of the other timbers.
The durability of totara under the most trying circumstances is well established and well known. I show a piece of a log found at an elevation of about 1,300 feet, on the Mount Pisa Ranges, where no tree has stood for centuries; it is as sound as when the Moa found shelter beneath its branches. I also show a survey peg from the division between Sections 1 and 2, Block X., Waihola survey district, put in by Mr. Kettle in 1848, and taken out in 1874, which is still quite fresh. All the oldest house blocks and fencing posts throughout the province that were of heart of totara are in the same condition, so further proof of its durability is unnecessary. I should, however, remark that piles or posts made of saplings with little heart-wood will not last long in the ground. Mr. Kirk, of Wellington, observed this in bridge piles, and I noticed it myself in fencing posts; the original telegraph poles on the Dunstan line also show the same thing. In black pine and old totara, where the heart-wood is solid, decay stops whenever the heart is reached; but such is not the case with totara saplings—the disease is communicated by the sap to the heart, and both perish together. Totara in the North Island stands the marine worm better than any other native timber, but it has not shown any great resisting powers here. The piles in the Bluff wharf were perforated to the heart, and very much riddled in a few years.
The totara of the west coast, which is generally smaller than that of the east is considered by Dr. Hector and Mr. Buchanan as a different tree, and Mr. page 158 A. C. Purdie informs me that there is a variety found at Catlin River not described by any of the botanists; it is of a large size, with a smooth bark, and yields very soft ornamental wood suitable for inside work.
No. 4. Black Pine—Podocarpus spicata. Like its two congeners already described, this tree frequents all the low lying forests of Otago, but it is more plentiful on the east than the west coast; the best supplies now available I are at Catlin River and Southland.
The tree grows to a height of from fifty to ninety feet, with a trunk twenty to thirty-five feet long and three to five feet in diameter; the latter, however, is an extreme size—four feet may be taken as the limit in ordinary cases. At Catlin River the sound trunks seldom exceed twenty-four feet in length and three feet in diameter. The appearance and properties of black pine have already been discussed in comparing it with miro, so it is only necessary to refer to the peculiarities of the former. The timber reaches maturity in about 400 years, and has about two inches of sap-wood when ripe. The tree is subject to a small heart-crack, which developes into decay when allowed to proceed, but the evil is not so great as in totara or cedar. Next to miro, this is the strongest and heaviest of the New Zealand; pinewoods, and it is, without exception, the least given to warping and shrinking, and in all probability the most durable. It is suitable for all the purposes for which totara is adapted, as well as others where greater strength and solidity are required.
Miro, having been frequently substituted for black pine in exposed situations throughout the province, has brought the latter into disrepute, and the resemblance is so great that professional men were afraid to run the risk of making a mistake. The consequence is that its good qualities are to this day little known and little appreciated. I show a portion of a fencing post cut and erected by Mr. Horman, at Makarewa, in June 1861, and taken up this month; the part most subjected to decay, that at the ground line, is perfectly sound. I have seen a black pine log, that had lain in the Waikiwi forest from time immemorial, as fresh as when it fell; it had been there so long that a fuchsia nine inches in diameter was growing across it. I show a few inches off the end of a log that lay for twelve years in a paddock at Seaward Bush; the sap is all worm-eaten, but the heart, even to the end, is quite solid. Mr. M'Arthur sent me, in 1872, a piece of a post that had been ten years in the ground at Waikiwi; the edges at the surface of the ground were almost as sharp as when split, and there were many more in that locality in the same condition. I have already referred to the sapling telegraph posts. Those of birch and totara were rotten through in twelve months, but the heart of the black pine ones, although very small, stood for five or six years; indeed, it was net decayed when the page 159 posts were removed to be replaced by iron ones. Black pine, however, does not stand the ravages of the marine worm as well as totara. The retaining wall at Rattray-street, erected in 1807 and recently removed, had been at-tacked, though so far from the open ocean.
Black pine and totara contain a resinous matter that resists the adhesion of paint when the timber is green. This property, which builders consider a serious objection, is, in reality, a great recommendation, for it promotes seasoning.
I have in this paper adhered to the popular name of black pine for this limber, but the native name matai, which is always used in the North, is becoming common in Otago also. I trust it will soon completely supersede the former.
No. 5. White Pine—Podocarpus dacrydioides. Although more gregarious than the other pines, this tree is found associated with its congeners in all the sub-alpine forests of Otago. It grows freest in low swampy ground, but the best timber is produced on moderately dry soil.
White pine grows to a height of from 120 to 150 feet, with a trunk up to seventy feet long and five feet in diameter at the base. One log lately examined on the Oreopuki railway measured fifty-five feet in length, five I feet in diameter at the butt., with three foot of solid heart-wood, and three feet in diameter at the top, with one foot of heart. At Catlin river the average dimensions of trunk is forty feet long, and from two feet six inches to four feet in diameter, the largest trees having about two feet of heart. As a rule there is seldom more than two or three inches of heart-wood in trees under three feet in diameter, and the difference between heart and sap-wood is in all eases very indistinct. The shape of the tree, colour of bark, and appearance generally are somewhat like black pine. Still there is little difficulty in distinguishing them when growing, and the difference in the wood is greater than between any other two of the pines. In consequence of the evenness of the colour, and the closeness of the annual rings, I it is difficult to estimate the age of white pine. Ordinary-sized trees probably reach maturity in from 370 to 600 years. Young trees are easily transplanted and cultivated. They shoot about eighteen inches per annum. Old trees have a slight heart crack, but it is too small to be considered a defect.
The sap-wood of white pine is of a dull white colour, and the heart-wood of a pale yellow or straw colour. It is the weakest and lightest of the native building timbers tested at the New Zealand Exhibition. Still its strength is about ten per cent, greater than that of European red deal and English elm, and its weight is much the same as the former. The wood is straight grained, soft, flexible, and not given to warping or excessive shrink- page 160 age, consequently it is well adapted for flooring, weather-boards, and the other ordinary joiners' work for which white deal is usually employed. Tradesmen will not allow a comparison to be made between the native and imported articles. They say the latter is infinitely superior, and that white pine is too soft and spongy for anything like good work. I do not think there are sufficient grounds for such a conclusion, which is in all probability arrived at by comparing seasoned foreign timber, the only kind that can be got here, with green colonial timber, the only kind that is used. The white pine timber of Otago is in my opinion equal, if not superior, to Baltic white deal for all the purposes for which the latter is adapted, and its supposed inferiority is due entirely to defective seasoning.
White pine is not durable in any situation where exposed to damp or frequent changes from wet to dry. It will not last two years in fencing posts or house blocks; even rails and beams of bridges that are clear of the ground decay in three or four years, the least moisture retained in a joint or mortice brings rapid destruction. The heart-wood is durable, but there is so little of it, and there is so much danger of using sap instead, that no advantage can be taken of its good qualities. I show a piece of white pine heart-wood taken from a large log that has been felled many years at Deborah Bay. It is still in good preservation. Some of the piles in the George street jetty, Port Chalmers, are of white pine. They are eaten away to a third of their original diameter by the Limnoria, but the timber has not suffered much from natural decay. Although soft and weak, the fibre is still intact. Mr Kirk says that white pine in Wellington and other places in the North is subject to the attack of a minute double-winged insect, but so far as I can ascertain it has no such enemy in Dunedin.
This timber is known in all the provinces except Otago by the native name of "kahikatea." I think we should adopt it also, not only on account of being more euphonious, but for the reason that so many timbers in other parts of the world are called white pine.