Man and Nature Part 34

kitchen implements are of copper or of clay, the ordinary tools for working wood are of a very inferior description, and the locust timber is found too hard for their temper. Southey informs us, in "Espriella's Letters," that when a small quant.i.ty of mahogany was brought to England, early in the last century, the cabinetmakers were unable to use it, from the defective temper of their tools, until the demand for furniture from the new wood compelled them to improve the quality of their implements.

In America, the cheapness of wood long made it the preferable material for almost all purposes to which it could by any possibility be applied.

The mechanical cutlery and artisans' tools of the United States are of admirable temper, finish, and convenience, and no wood is too hard, or otherwise too refractory, to be wrought with great facility, both by hand tools and by the mult.i.tude of ingenious machines which the Americans have invented for this purpose.

[284] _etudes Forestieres_, p. 7.

[285] _etudes Forestieres_, p. 7.

[286] For very full catalogues of American forest trees, and remarks on their geographical distribution, consult papers on the subject by Dr. J.

G. Cooper, in the Report of the Smithsonian Inst.i.tution for 1858, and the Report of the United States Patent Office, Agricultural Division, for 1860.

[287] Although Spenser's catalogue of trees occurs in the first canto of the first book of the "Faery Queene"--the only canto of that exquisite poem actually read by most students of English literature--it is not so generally familiar as to make the quotation of it altogether superfluous:

VII.

Enforst to seeke some covert nigh at hand, A shadie grove not farr away they spide, That promist ayde the tempest to withstand; Whose loftie trees, yelad with sommers pride, Did spred so broad, that heavens light did hide, Not perceable with power of any starr: And all within were pathes and alleies wide, With footing worne, and leading inward farr; Faire harbour that them seems; so in they entred ar.

VIII.

And foorth they pa.s.se, with pleasure forward led, Joying to heare the birdes sweete harmony, Which therein shrouded from the tempest dred, Seemd in their song to scorne the cruell sky.

Much can they praise the trees so straight and hy, The sayling pine; the cedar stout and tall; The vine-propp elm; the poplar never dry; The builder oake, sole king of forrests all; The aspine good for staves; the cypresse funerall;

IX.

The laurell, meed of mightie conquerours And poets sage; the firre that weepeth still; The willow, worne of forlorn paramours; The eugh, obedient to the benders will; The birch for shaftes; the sallow for the mill; The mirrhe sweete-bleeding in the bitter wound; The warlike beech; the ash for nothing ill; The fruitfull olive; and the platane round; The carver holme; the maple seeldom inward sound.

[288] The walnut is a more valuable tree than is generally supposed. It yields one third of the oil produced in France, and in this respect occupies an intermediate position between the olive of the south, and the oleaginous seeds of the north. A hectare (about two and a half acres), will produce nuts to the value of five hundred francs a year, which cost nothing but the gathering. Unfortunately, its maturity must be long waited for, and more nut-trees are felled than planted. The demand for its wood in cabinet work is the princ.i.p.al cause of its destruction. See LAVERGNE, _economie Rurale de la France_, p. 253.

According to Cosimo Ridolfi (Lezioni Orali, ii. p. 424), France obtains three times as much oil from the walnut as from the olive, and nearly as much as from all oleaginous seeds together. He states that the walnut bears nuts at the age of twenty years, and yields its maximum product at seventy, and that a hectare of ground, with thirty trees, or twelve to the acre, is equal to a capital of twenty-five hundred francs.

The nut of this tree is known in the United States as the "English walnut." The fruit and the wood much resemble those of the American black walnut, _Juglans nigra_, but for cabinet work the American is the more beautiful material, especially when the large knots are employed.

The timber of the European species, when straight grained, and _clear_, or free from knots, is, for ordinary purposes, better than that of the American black walnut, but bears no comparison with the wood of the hickory, when strength combined with elasticity is required, and its nut is very inferior in taste to that of the s.h.a.gbark, as well as to the b.u.t.ternut, which it somewhat resembles.

"The chestnut is more valuable still, for it produces on a sterile soil, which, without it, would yield only ferns and heaths, an abundant nutriment for man."--LAVERGNE, _economie Rurale de la France_, p. 253.

I believe the varieties developed by cultivation are less numerous in the walnut than in the chestnut, which latter tree is often grafted in Southern Europe.

[289] This fir is remarkable for its tendency to cicatrize or heal over its stumps, a property which it possesses in common with some other firs, the maritime pine, and the European larch. When these trees grow in thick clumps, their roots are apt to unite by a species of natural grafting, and if one of them be felled, although its own proper rootlets die, the stump may continue, sometimes for a century, to receive nourishment from the radicles of the surrounding trees, and a dome of wood and bark of considerable thickness be formed over it. The cicatrization is, however, only apparent, for the entire stump, except the outside ring of annual growth, soon dies, and even decays within its covering, without sending out new shoots.

[290] At the age of twelve or fifteen years, the cork tree is stripped of its outer bark for the first time. This first yield is of inferior quality, and is employed for floats for nets and buoys, or burnt for lampblack. After this, a new layer of cork, an inch or an inch and a quarter in thickness, is formed about once in ten years, and is removed in large sheets without injury to the tree, which lives a hundred and fifty years or more. According to Clave (p. 252), the annual product of a forest of cork oaks is calculated at about 660 kilogrammes, worth 150 francs, to the hectare, which, deducting expenses, leaves a profit of 100 francs. This is about equal to 250 pound weight, and eight dollars profit to the acre. The cork oaks of the national domain in Algeria cover about 500,000 acres, and are let to individuals at rates which are expected, when the whole is rented, to yield to the state a revenue of about $2,000,000.

George Sand, in the _Histoire de ma Vie_, speaks of the cork forests in Southern France as among the most profitable of rural possessions, and states, what I do not remember to have seen noticed elsewhere, that Russia is the best customer for cork. The large sheets taken from the trees are slit into thin plates, and used to line the walls of apartments in that cold climate.

[291] The walnut, the chestnut, the apple, and the pear are common to the border between the countries I have mentioned, but the range of the other trees is bounded by the Alps, and by a well-defined and sharply drawn line to the west of those mountains. I cannot give statistical details as to the number of any of the trees in question, or as to the area they would cover if brought together in a given country. From some peculiarity in the sky of Europe, cultivated plants will thrive, in Northern Italy, in Southern France, and even in Switzerland, under a depth of shade where no crop, not even gra.s.s, worth harvesting, would grow in the United States with an equally high summer temperature. Hence the cultivation of all these trees is practicable in Europe to a greater extent than would be supposed reconcilable with the interests of agriculture. Some idea of the importance of the olive orchards may be formed from the fact that Sicily alone, an island scarcely exceeding 10,000 square miles in area, of which one third at least is absolutely barren, has exported to the single port of Ma.r.s.eilles more than 2,000,000 pounds weight of olive oil per year, for the last twenty years.

[292] It is hard to say how far the peculiar form of the graceful crown of this pine is due to pruning. It is true that the extremities of the topmost branches are rarely lopped, but the lateral boughs are almost uniformly removed to a very considerable height, and it is not improbable that the shape of the top is thereby affected.

[293] Besides this, in a country so diversified in surface--I wish we could with the French say _accidented_--as Italy with the exception of the champaign region drained by the Po, every new field of view requires either an extraordinary _coup d'[oe]il_ in the spectator, or a long study, in order to master its relief, its plans, its salient and retreating angles. In summer, the universal greenery confounds light and shade, distance and foreground; and though the impression upon a traveller, who journeys for the sake of "sensations," may be strengthened by the mysterious annihilation of all standards for the measurement of s.p.a.ce, yet the superior intelligibility of the winter scenery of Italy is more profitable to those who see with a view to a.n.a.lyze.

[294] Copse, or coppice, from the French _couper_, to cut, signifies properly a wood the trees of which are cut at certain periods of immature growth, and allowed to shoot up again from the roots; but it has come to signify, very commonly, a young wood, grove, or thicket, without reference to its origin, or to its character of a forest crop.

[295] It has been recently stated, upon the evidence of the Government foresters of Greece, and of the queen's gardener, that a large wood has been discovered in Arcadia, consisting of a fir which has the property of sending up both vertical and lateral shoots from the stump of felled trees and forming a new crown. It was at first supposed that this forest grew only on the "mountains," of which the hero of About's most amusing story, _Le Roi des Montagnes_, was "king;" but it is now said that small stumps, with the shoots attached, have been sent to Germany, and recognized by able botanists as true natural products.

[296] Natural forests are rarely, if ever, composed of trees of a single species, and experience has shown that oaks and other broad-leaved trees, planted as artificial woods, require to be mixed, or a.s.sociated with others of different habits.

In the forest of Fontainebleau, "oaks, mingled with beeches in due proportion," says Clave, "may arrive at the age of five or six hundred years in full vigor, and attain dimensions which I have never seen surpa.s.sed; when, however, they are wholly unmixed with other trees, they begin to decay and die at the top, at the age of forty or fifty years, like men, old before their time, weary of the world, and longing only to quit it. This has been observed in most of the oak plantations of which I have spoken, and they have not been able to attain to full growth.

When the vegetation was perceived to languish, they were cut, in the hope that this operation would restore their vigor, and that the new shoots would succeed better than the original trees; and, in fact, they seemed to be recovering for the first few years. But the shoots were soon attacked by the same decay, and the operation had to be renewed at shorter and shorter intervals, until at last it was found necessary to treat as coppices plantations originally designed for the full-growth system. Nor was this all: the soil, periodically bared by these cuttings, became impoverished, and less and less suited to the growth of the oak. * * * It was then proposed to introduce the pine and plant with it the vacancies and glades. * * * By this means, the forest was saved from the ruin which threatened it, and now more than 10,000 acres of pines, from fifteen to thirty years old, are disseminated at various points, sometimes intermixed with broad-leaved trees, sometimes forming groves by themselves."--_Revue des Deux Mondes_, Mai, 1863, pp. 153, 154.

The forests of Denmark, which, in modern times, have been succeeded by the beech--a species more inclined to be exclusive than any other broad-leaved tree--were composed of birches, oaks, firs, aspens, willows, hazel, and maple, the first three being the leading species. At present, the beech greatly predominates.--VAUPELL, _Bogens Indvandring_, pp. 19, 20.

[297] _etudes Forestieres_, p. 89.

[298] The grounds which it is most important to clothe with wood as a conservative influence, and which, also, can best be spared from agricultural use, are steep hillsides. But the performance of all the offices of the forester to the tree--seeding, planting, thinning, and finally felling and removing for consumption--is more laborious upon a rapid declivity than on a level soil, and at the same time it is difficult to apply irrigation or manures to trees so situated.

Experience has shown that there is great advantage in terracing the face of a hill before planting it, both as preventing the wash of the earth by checking the flow of water down its slope, and as presenting a surface favorable for irrigation, as well as for manuring and cultivating the tree. But even without so expensive a process, very important results have been obtained by simply ditching declivities. "In order to hasten the growth of wood on the flanks of a mountain, Mr.

Eugene Chevandier divided the slope into zones forty or fifty feet wide, by horizontal ditches closed at both ends, and thereby obtained, from firs of different ages, shoots double the dimensions of those which grew on a dry soil of the same character, where the water was allowed to run off without obstruction."--DUMONT, _Des Travaux Publics, etc._, pp.

94-96.

The ditches were about two feet and a half deep, and three feet and a half wide, and they cost about forty francs the hectare, or three dollars the acre. This extraordinary growth was produced wholly by the retention of the rain water in the ditches, whence it filtered through the whole soil and supplied moisture to the roots of the trees. It may be doubted whether in a climate cold enough to freeze the entire contents of the ditches in winter, it would not be expedient to draw off the water in the autumn, as the presence of so large a quant.i.ty of ice in the soil might prove injurious to trees too young and small to shelter the ground effectually against frost.

Chevandier computes that, if the annual growth of the pine in the marshy soil of the Vosges be represented by one, it will equal two in dry ground, four or five on slopes so ditched or graded as to retain the water flowing upon them from roads or steep declivities, and six where the earth is kept constantly moist by infiltration from running brooks.--_Comptes Rendus a l'Academie des Sciences_--t. xix, Juillet, Dec., 1844, p. 167.

The effect of accidental irrigation is well shown in the growth of the trees planted along the ca.n.a.ls of irrigation which traverse the fields in many parts of Italy. They flourish most luxuriantly, in spite of continual lopping, and yield a very important contribution to the stock of fuel for domestic use; while trees, situated so far from ca.n.a.ls as to be out of the reach of infiltration from them, are of much slower growth, under circ.u.mstances otherwise equally favorable.

In other experiments of Chevandier, under better conditions, the yield of wood was increased, by judicious irrigation, in the ratio of seven to one, the profits in that of twelve to one. At the Exposition of 1855, Chambrelent exhibited young trees, which, in four years from the seed, had grown to the height of sixteen and twenty feet, and the diameter of ten and twelve inches. Chevandier experimented with various manures, and found that some of them might be profitably applied to young, but not to old trees, the quant.i.ty required in the latter case being too great.

Wood ashes and the refuse of soda factories are particularly recommended. I have seen an extraordinary growth produced in fir trees by the application of soapsuds.

[299] Although the economy of the forest has received little attention in the United States, no lover of American nature can have failed to observe a marked difference between a native wood from which cattle are excluded and one where they are permitted to browse. A few seasons suffice for the total extirpation of the "underbrush," including the young trees on which alone the reproduction of the forest depends, and all the branches of those of larger growth which hang within reach of the cattle are stripped of their buds and leaves, and soon wither and fall off. These effects are observable at a great distance, and a wood pasture is recognized, almost as far as it can be seen, by the regularity with which its lower foliage terminates at what Ruskin somewhere calls the "cattle line." This always runs parallel to the surface of the ground, and is determined by the height to which domestic quadrupeds can reach to feed upon the leaves. In describing a visit to the grand-ducal farm of San Rossore near Pisa, where a large herd of camels is kept, Chateauvieux says: "In pa.s.sing through a wood of evergreen oaks, I observed that all the twigs and foliage of the trees were clipped up to the height of about twelve feet above the ground, without leaving a single spray below that level. I was informed that the browsing of the camels had trimmed the trees as high as they could reach."--LULLIN DE CHATEAUVIEUX, _Lettres sur l'Italie_, p. 113.

The removal of the shelter afforded by the brushwood and the pendulous branches of trees permits drying and chilling winds to parch and cool the ground, and of course injuriously affects the growth of the wood.

But this is not all. The tread of quadrupeds exposes and bruises the roots of the trees, which often die from this cause, as any one may observe by following the paths made by cattle through woodlands.

[300] I have remarked elsewhere that most insects which deposit and hatch their eggs in the wood of the natural forest confine themselves to dead trees. Not only is this the fact, but it is also true that many of the borers attack only freshly cut timber. Their season of labor is a short one, and unless the tree is cut during this period, it is safe from them. In summer you may hear them plying their augers in the wood of a young pine with soft green bark, as you sit upon its trunk, within a week after it has been felled, but the windfalls of the winter lie uninjured by the worm and even undecayed for centuries. In the pine woods of New England, after the regular lumberman has removed the standing trees, these old trunks are hauled out from the mosses and leaves which half cover them, and often furnish excellent timber. The slow decay of such timber in the woods, it may be remarked, furnishes another proof of the uniformity of temperature and humidity in the forest, for the trunk of a tree lying on gra.s.s or plough land, and of course exposed to all the alternations of climate, hardly resists complete decomposition for a generation. The forests of Europe exhibit similar facts. Wessely, in a description of the primitive wood of Neuwald in Lower Austria, says that the windfalls required from 150 to 200 years for entire decay.-_-Die Oesterreichischen Alpenlander und ihre Forste_, p. 312.

[301] VAUPELL, _Bogens Indvandring i de Danske Skove_, pp. 29, 46.

Vaupell further observes, on the page last quoted: "The removal of leaves is injurious to the forest, not only because it r.e.t.a.r.ds the growth of trees, but still more because it disqualifies the soil for the production of particular species. When the beech languishes, and the development of its branches is less vigorous and its crown less spreading, it becomes unable to resist the encroachments of the fir.

This latter tree thrives in an inferior soil, and being no longer stifled by the thick foliage of the beech, it spreads gradually through the wood, while the beech retreats before it and finally perishes."

The study of the natural order of succession in forest trees is of the utmost importance in sylviculture, because it guides us in the selection of the species to be employed in planting a new or restoring a decayed forest. When ground is laid bare both of trees and of vegetable mould, and left to the action of unaided and un.o.bstructed nature, she first propagates trees which germinate and grow only under the influence of a full supply of light and air, and then, in succession, other species, according to their ability to bear the shade and their demand for more abundant nutriment. In Northern Europe, the larch, the white birch, the aspen, first appear; then follow the maple, the alder, the ash, the fir; then the oak and the linden; and then the beech. The trees called by these respective names in the United States are not specifically the same as their European namesakes, nor are they always even the equivalents of these latter, and therefore the order of succession in America would not be precisely as indicated by the foregoing list, but it nevertheless very nearly corresponds to it.

It is thought important to encourage the growth of the beech in Denmark and Northern Germany, because it upon the whole yields better returns than other trees, and particularly because it appears not to exhaust, but on the contrary to enrich the soil; for by shedding its leaves it returns to it most of the nutriment it has drawn from it, and at the same time furnishes a solvent which aids materially in the decomposition of its mineral const.i.tuents.

When the forest is left to itself, the order of succession is constant, and its occasional inversion is always explicable by some human interference. It is curious that the trees which require most light are content with the poorest soils, and _vice versa_. The trees which first appear are also those which propagate themselves farthest to the north.

The birch, the larch, and the fir bear a severer climate than the oak, the oak than the beech. "These parallelisms," says Vaupell, "are very interesting, because they are entirely independent of each other," and each prescribes the same order of succession.--_Bogens Indvandring_, p.

42.

[302] When vigorous young locusts, of two or three inches in diameter, are polled, they throw out a great number of very thick-leaved shoots, which arrange themselves in a globular head, so unlike the natural crown of the acacia, that persons familiar only with the untrained tree often take them for a different species.

[303] The two ideas expressed in the text are not exactly equivalent, because, though the consumption of animal food diminishes the amount of vegetable aliment required for human use, yet the animals themselves consume a great quant.i.ty of grain and roots grown on ground ploughed and cultivated as regularly and as laboriously as any other.