After these rather lengthy references to facts, we must allude to a circumstance which we are astonished has not been attended to by Mr Withers, and his gentlemen correspondents connected with His Majesty’s docks,—the not taking into account the place of the tree whence the portion of wood for experimenting the strength had been taken, and also how the annual layers stood, whether horizontal or on edge, or around a centre, when the weight was applied. The experienced and accurately practical Mr Withers presents two specimens of oak, the one of faster and the other of slower growth, to Professor Barlow, of Woolwich Royal Academy, and the strength of these specimens is tested and reported upon, without once alluding to what we have mentioned above. Now, if this has not been attended to, the experiment may be considered a test of something else than of the timber. How much the strength is affected by the place of the tree, any person may satisfy himself by proving one piece of timber taken from near the root, another half way up the tree, and a third near the top: he will find that in a tall tree the comparative {212} strength will sometimes vary as much as 3, 2, 1; that is, a beam, say 2 inches square, and 4 feet long, taken from near the root, when horizontally placed, and resting only at each end, will support three times as much as a like beam in like position from near the top of the tree, although both are equally clear of knots or cross section of grain. This is particularly manifest in large fast-grown silver fir and old ash, and the difference is always greatest in old trees. He will also find that the position of the beam, in respect to the layers being circular round the heart, flat, on edge, or at an angle, has considerable influence, and, should he inquire farther, will perhaps notice, that the timber from different sides of the tree is not always alike strong; that one specimen of timber will be superior to another, both being moist, and inferior to it when both are dry, and that also, as in No. 1, the tree at the same height on the same side, will contain timber differing in strength fully one half, and not always diminishing in strength from the heart outwards, even in hard wood. We are well pleased with one gentleman of the Navy Dock-yard, who naively admits, that he is incompetent to decide on these subjects, having been altogether devoted to the mathematical, in estimating the strain and resistance timber suffers under {213} different combinations. Now we like this division of labour.
But to return to our subject. The facts stated go to prove, that the quality of timber depends much upon soil, circumstance, and more especially on variety; and that in the early period of the growth of trees, before much seeding, and when the soil is not much exhausted of the particular pabulum necessary for the kind of plant, that rather slow grown timber is superior in strength to quick grown, especially when the quickness exceeds a certain degree; when this degree is exceeded, the timber is not so weighty, and is well known not to be so durable. However, when timber is required of considerable scantling, it is only in good soils, where the tree increases moderately fast, that timber will attain sufficient size for this, at an age young enough to retain its toughness throughout, or to continue forming firm dense wood on the exterior. This is particularly so in the case of hard-wood timber, more especially when oak grows upon a moist soil, where the matured wood, of brownish-red colour, is often unsound, and where decay commences at a comparatively early period. In the pine, owing to the oleaginous undrying nature of the sap (resin), the {214} timber retains its strength to a great age; and the reedy closeness of slow growth, for most purposes, outbalances any loss from deficiency of lateral adhesion.
Moderately fast grown timber is much more requisite for naval purposes than for other uses; as, besides the greater longitudinal strength when of large dimension, it has greater adhesion laterally, is far more pliant, and therefore much better suited for the ribs of vessels, where cross cutting a portion of the fibre, from the inattention to training to proper bends, is unavoidable; and whence a disrupting shock (which is rather to be withstood than fair pressure), makes the unyielding splintering old wood fly like ice; the rift commencing its run from the cut fibre. For plank, the lateral adhesion and pliancy of young moderately fast grown timber is equally valuable, especially for those which are applied to the curvature of the bow and stern. Young timber also softens much better by steam, therefore is more convenient for planking, and for being bent for the compass timbers of large vessels. The vessel constructed of it will besides, from the general elasticity of the fibre, be more lively in the water, sail faster, and, though stronger to resist, will {215} have less strain to endure[47]. Mr Withers’s corresponding friends, especially those of his Majesty’s Dock-yards, with the good common sense of practical men, are well acquainted with all this, although they get a little out of element when they meddle with nature or causes. Mr Withers is himself equally out of element when he expatiates on the mighty advantage of trenching and manuring at planting, and when he talks of our Scottish holes. The Knight, too, is still more at fault in dreading any great influence on the quickness of the growth of trees from this gentleman’s new inventions,—and doubly at fault, from conjecturing our navy would suffer from being constructed of the fastest grown British timber there is any chance of our shipwrights obtaining. Since we were in our teens, we have almost every season trenched a portion of ground for planting, and have manured highly at planting[48], {216} and for several years afterwards. We have found, when very adhesive subsoil was brought upward, that the trees throve well while the ground continued under cultivation; but when the labour ceased, they were soon overtaken by those planted at the same time without trenching. This comparative falling off was evidently owing to the surface being rendered more adhesive by the gluey plastic subsoil being mixed upward with the original small portion of surface-mould. This new surface melted to a pulp by the winter rains, when drought set in spring, run together, became indurated, and parting into divisions, admitted the drought down to the unstirred ground by numerous deep and wide cracks, which rent the rootlets of the trees, and rendered it impossible for any plant to thrive. There are also many kinds of light subsoil, which it would be folly to bring to the surface, and where little profit would arise from deep stirring, even though the surface were retained uppermost.
In cases where the plants were very small, we have found deep trenching of no benefit, but in certain {217} soils rather hurtful, even during the first years; but with larger plants, such as are often used in England, it invariably occasioned their roots to strike quickly, by affording a regular supply of moisture, and from being easily permeated by the rootlets, expedited the growth, yielding much early luxuriance when followed by skilful culture, but latterly, seldom to such a degree as would lead us to suppose much difference would be discernible at 30 years of age, between the trenched and those planted by mere pitting, slitting, or sowing,—much more depending on proper draining, on young, thriving, small sturdy plants, of best variety,—on suiting the plant to the soil and climate, and on timely thinning.
But even were a very superior ultimate progress of growth obtained by trenching, manuring, and culture of timber, yet as capital and manure will probably be more advantageously employed in common agriculture, which gives a comparatively quick return of both, we shall leave to Mr Withers and his coterie of illuminati the whole advantage of his discovery. Economic philosophy is the queen of our Scottish plants; she will not admit any new system of nurture for her subjects without the {218} strictest scrutiny of its utility as applied to her domains,—she proceeds thus to weigh Mr Withers’s practice:—
| Twenty loads of putrescent manure, at the average price at which thousands of tons are annually imported to the valley of the Tay from England, 9s. per load, | L.9 | 0 | 0 |
| Carriage expenses of above, at 3s. per load, | 3 | 0 | 0 |
| Twenty loads calcareous manure, including carriage (were marl not at hand, lime would cost thrice as much), | 4 | 0 | 0 |
| Trenching, | 9 | 0 | 0 |
| Total first extra cost, | L.25 | 0 | 0 |
| Accumulation by 28 years’ interest, at 5 per cent. nearly, | L.100 | 0 | 0 |
Would land under timber 28 years planted, with growth accelerated by Mr Withers’s practice, in two-thirds of the available portion of Scotland, sell at more than L. 100 per English acre? Suppose that the thinnings previous to the 28th year would cover the cost of planting, and subsequent cultivation and attention which is necessary, besides {219} the cost of the trenching and manuring (in many cases they would not), the entire value of the land would be lost. It may be said that the common rules of utility do not apply in this case,—that the landlords will not be moved to any other improvement than planting, and that otherwise their income would be dissipated entirely, without any portion being applied to reproductive uses. We grant all this; but Scottish landlords have very little taste for the Withers’ system,—to deface their beautiful wastes, by burying all the fine turf and wildflowers under the red mortar (the common subsoil), or to scatter manure. Planting by pitting and slitting will prove far more attractive; besides, the means are entirely awanting to carry on such expensive proceedings to the necessary extent, and the cultivation of one acre in this fashion would leave 19 untouched, when the whole 20 might have been wooded, in many cases to equal advantage, by the money expended on one. We have known planting executed by contract for one year’s interest of the above stated first extra expenditure, which we would match against planting raised by Mr Withers’s process, in the same situation. There is also a very considerable proportion of Scotland very suitable for {220} timber where the stony nature of the surface entirely precludes trenching.
Mr Withers, who appears to have no general knowledge of soils and climates, would hold a different language with regard to Scotland and Scotsmen, if he saw the beautiful thriving plantations now rising in that country, planted by mere pitting and slitting, where, owing to the drought in early summer being less fierce than what occurs in the central, eastern, and southern counties of England, and to the herbage being less luxuriant, planting without trenching can always be depended upon. Mr Withers would also have been sensible had he had much practice in rural affairs, that twenty loads of putrid manure per acre at planting, although of very considerable advantage for two or three seasons to the rising trees, in promoting, along with hoeing and digging, an early start to luxuriance, would cause little or no lasting amelioration of the soil; That the vegetable mould naturally occupying the surface is generally by itself a much better defence against the summer’s drought, than when incorporated with the subsoil, especially after cultivation ceases; that lasting fertility of ground for timber, though sometimes, is often not increased by admixture of soil {221} and subsoil; and that, generally, the luxuriance of the tree must ultimately depend on the natural depth and quality of the ground itself.
Mr Withers, with that precise knowledge of the subject, and clear conception of the nature of things, which generally accompanies a partial acquaintance with facts, makes a confident and rather imposing appearance as a wielder of language and a logician. From his assumed superiority, we especially wonder that he should possibly have envy of Scotsmen, which, from the tenor of his letter, we are constrained to believe. Need Caledonia remind her noble sister, England, of their consanguinity,—that they are sisters whom nature hath twinned together? Is there another in all the earth, with quadruple the advantages of Scotland, who can rank with her in science and literature, arts and arms? And is England not proud of her poorer sister? Or can they feel aught but mutual love?
