Our eastern shore affords sufficient proof that the ocean has both receded and advanced recently—at least recently in comparison with the great changes which have occurred to modify the surface of the earth. In proof of this recession, we have the upper carses, or deltas, visible in every firth or creek where a river falls into the German Sea. These carses, on the firths in Ross-shire, at Dun near Montrose, around the upper end of the Firths of Tay and Forth, are all of nearly equal level, about 20 feet above the highest stream-tides. The gravel bar at Montrose is considerably above the present sea-level. A number of caves exist on this {290} eastern coast, evidently worn into the rock by the action of the sea at the height where the waves have broken. These caves have nearly one level, corresponding in height with that of the carses. There are also many places where the coast has been shorn away by the action of the waves, and a shelf of rocks left extending out some hundred paces. This abrasion, which takes place nearly at, or a little above, low water-mark, is effected by innumerable hard pebbles (the most indurated parts of the rocks which give way being converted into battering material for further reduction), being upborne and dashed against the rock by the continuous heaving and lashing of the waves. Wherever any breach commences from the feebler opposition of any softer part, the action of the waves and battering train proceeds with increased impetus and concentration, especially if the breach be wedge-shaped narrowing inward, thence caves of considerable extent are hallowed out. The rocks thus abraded and undermined, tumble down and are ground into sand, which is swept by the tides and motion of the waters into the depths of the ocean, or borne along to the upper end of the bays, or to some part of the coast where more sluggish lateral tides, and particular motion of the waves leave it and throw it ashore to be blown up into {291} downs. There are some former islands which have been altogether shorn down to this sea-level, of which the Bell-Rock, extending nearly a mile of shelf, affords a well known specimen. In many places of the coast, these shelves accord with the superior former level of the sea, and with the floors of the caves.
In proof of the sea having advanced upon the land, there are vestiges of submerged forests (the stumps of the trees standing erect where they grew, at or a little above the present lowest ebb) existing at different places on the eastern coast, both of England and Scotland, and these vestiges standing upon a former carse or alluvium of the rivers, are visible in the same firths with the upper level of carse, of course generally more to seaward than these higher carses, as deposition of rivers occurs at what may be termed deposition point, that is where the rivers, from the stemming of the sea-water, begin to widen—where the firths commence; and the slowness of the motion of the water gives time for the subsidence of the floated mud. By reason of the flux and reflux of the tide into the mouths of rivers, this deposition takes place only at or near high water, that is, when the strength of the inward tide-flux ceases, and before that of the reflux begins. It is {292} most abundant at the windward shore, or where there is least surf, and among the tall gramina and other vegetation where there is least undulation and current; the deposition which occurs at this time, some distance below high water level, is floated away by the current of the following flux and reflux, unless some object afford a nucleus of formation. Hence deltas or carses usually form near the shore of firths, generally soon rise to high-water level, and have often steep, or even abrupt, banks, collecting at one place, and giving way before the waves and undermining current at another. There is a deposition of another kind than river diluvium, which also takes place at the bottom, or further end, of bays and firths, and is sometimes mixed with the preceding: This consists, as mentioned above, of the abrasion of the rocks, or shores of the bay and neighbouring coast, and also of molluscous exuviæ, borne along by the motion of the waters; but this is generally rather an accumulation than a deposition, occurring in greatest quantity where a heavy swell rolls dead in.
Although we have pretty accurate proof that the present elevation of the German Sea has remained nearly steady for several hundred years, yet our new formation of carse, at the present high-water level, {293} bears a small proportion to the extent of the upper carse; from which may be inferred, either that the sea has remained a shorter time at the present level, or that some general cause has more recently operated to diminish the deposition, such as inferiority of present climate not producing so much littoral vegetation,—tides or higher winds preventing subsidence by greater undulation or current, till the diffused mud be carried out to sea[59]. The junction of the higher and present sea-level carses, abrupt and always definite, that is, not gradually declining from the one to the other, would seem to indicate a quick subsiding of the sea, or rising of the land, such as has been known to result from subterraneous derangement. The very accurate level of these carses proves, that this portion of the world has remained a very long time pretty free from these disturbances, recently so prevalent in some other quarters; and if the change of sea-level has been owing to such disturbance, it follows, from the extent and regularity of the upheaving or subsidence, that the cause must have been very deep seated, or of great magnitude.
We begin to think, from our disposition to ramble from the Allanton system, that we tire of Sir {294} Henry; and we believe, should he follow us thus far, that he will be tired of us. On looking back on what we have written, we are almost disposed to accuse ourselves of being splenetic; but the truth is, we regard the whole art as very unimportant, if not positively pernicious, at least in the way in which it has been exemplified by Sir Henry, as a throwing away of valuable labour to no purpose, if it ought not indeed to be considered as a mere pander to luxury and caprice. We have no sympathy with the aristocratical object of the book, and as little with the aristocratical tone in which it has been bepraised by Sir Walter Scott. We should also have no greater pleasure in the discovery of a royal road to virtue than we should have to the discovery of one to science,—the four cardinal virtues being, as every body knows, writing books, building houses, and raising trees and children, but we should hope, neither by proxy, nor by the Allanton System. While, however, we thus state our opinions with freedom, we do not hesitate to add, that Sir Henry’s volume has afforded us more information, or, at least, more materials for reflection, than any other of the works which we have brought under the notice of our readers. {295}
We shall finish our remarks on Sir Henry’s work, by making some observations upon a quotation made by Sir Henry Steuart, from “A Treatise on the Forming and Improving of Country Residences,” by the Author of the Encyclopædia of Gardening, &c.—an author, who combines talent, successful industry, and enlightened benevolence, in no common degree. We are sorry to appear before this author, whom we have long esteemed, in opposition; yet we regret the less, as we consider him one of the few who prefer accuracy and truth to an old opinion, and whose name stands too high to be affected by a casual misconception.
“The general effects of pruning,” says this author, as quoted by Sir Henry Steuart, “is of a corresponding nature with culture, that is, to increase the quantity of timber-produce: the particular manner in which it does this is by directing the greater part of the sap, which generally spreads itself into side branches, into the principal stem. This must consequently enlarge the stem in a more than ordinary degree, by increasing the annual circles of the wood. Now, if the tree be in a worse soil and climate than those which are natural to it, this will be of some advantage, as the extra increase of {296} timber will still be of a quality not inferior to what would take place in its natural state; or, in other words, it will correspond with that degree of quality and quantity of timber, which the nature and species of the tree admit of being produced. If the tree be in its natural state, the annual increase of timber occasioned by pruning, must necessarily injure its quality in a degree corresponding with the increased quantity. If the tree be in a better climate and soil than that which is natural to it, and at the same time the annual increase of wood be promoted by pruning, it is evident that such wood must be of a very different quality from that produced in its natural state (that is very inferior).”—“Whatever tends to increase the wood in a greater degree than what is natural to the species when in its natural state, must injure the quality of the timber. Pruning tends to increase this in a considerable degree, and therefore it must be a pernicious practice.”—“Mr Knight has shown, in a very striking manner, that timber is produced, or rather that the alburnum or sap-wood is rendered ligneous, by the motion of the tree, during the descent of the tree (or proper) sap. It is also sufficiently known, that the solid texture of the wood greatly depends upon the quantity of sap which must necessarily {297} descend, and also on the slowness of the descent. Now, both these requisites are materially increased by side-branches, which retain a large quantity of sap, and, by their junction with the stem, occasion a contraction and twisted direction of the vessels, which obstructs the progress of the (proper) sap. Of maple and birch, those trees which have fewest side-branches bleed more freely than the other, but during a much shorter space of time. These hints, therefore, afford additional evidence against pruning, and particularly against pruning fir trees, which, as Mr Knight justly observes, have larger vessels than the others, and therefore, when in an improved soil and climate, side-branches for the purposes above mentioned are essentially necessary to them, if solid, resinous, and durable timber be the object in view.
“From the foregoing remarks, I think the following conclusions may be drawn.
“First, That trees should be planted as much as possible in soils, situations, and climates, analogous to those of their natural state; and that it is chiefly in this state, or when there are some defects relative to it, that pruning or culture can be exercised with advantage. {298}
“Secondly, That in proportion to the superiority of the soil, &c. in which trees are placed, over the natural soil of these trees, in the same proportion pruning and cultivating the soil ought to be avoided, and thinning encouraged.
“Thirdly, That particular regard should be had to the soil and situation, where either larches, or any other of the pine tribe, are planted, to remain as the final crop. For as the roots of these chiefly run along the surface, and as in them the great current of the sap is chiefly confined to one channel, that is the trunk, consequently that tribe of trees is peculiarly liable to injury and change, when subjected to unnatural agency.
“Fourthly, That the only way in which oak timber of safe quality can be provided for the British navy, is by enclosing, preserving from cattle, and properly managing, those royal forests where oak is the natural produce of the soil. (Alas! there is reason to fear, that on some future day the neglect of this advice will be regretted). Park oak is very frequently much inferior to forest oak in durability.”
We differ from the author of the Encyclopædia of Gardening here, even in limine, in his {299} assumption, that pruning is of a corresponding nature with culture, in increasing the annual circles of the wood[60]. Culture, if judiciously executed, increases these annual circles; but common pruning up (which, from the general bearing of the language, we suppose is meant), nine times out of ten diminishes them, and merely tends to extend the stem in length, by throwing all the new formation of branches to the top of the tree, in place of partly to the sides. Thence the tree acquires a slenderer figure, and more delicate constitution; and from greater height, and being without cover of side-branches, loses more by evaporation, and receives less moisture from the ground, which is dried by the breeze passing along under the branches; the principal process of vegetation, assimilation by the leaves, being reduced by the pruning, and carried on at an unnatural height, in a colder less genial atmosphere, under a diminished supply of nourishment from the ground, is consequently less productive of new assimilized {300} matter; and this smaller quantity requiring to be extended along a greater length of stem, the annual rings are necessarily thinner.
We admit that a tree becomes more stemmy by being repeatedly pruned up;—we admit, that, on removal of the lower branches, the upper part of the stem may have, for a few seasons, larger annual circles; but the annual circles will be diminished in thickness in a much greater proportion on the lower part of the stem;—we admit, that the timber, from being deposited in a clean lengthened cylinder, becomes far more useful, there being less redundant matter than when scattered out into stemmy branches, to which disposition, trees in open situation sometimes incline, especially if not transplanted very young, but to which they are nevertheless much more disposed under the common mode of pruning in an early stage of their growth, than when left to themselves;—we admit, that trees, by pruning, raised to lengthened stem, and thence performing less assimilation, partly compensate for this less assimilation, for some time, by making more stem deposit in proportion to the other deposit, which extends the parts more immediately necessary to new formation,—the roots and twigs; but the deficiency of productory parts soon {301} reacts to diminish the amount of all the new products. In tall trees, this greater deposition on the stem, in proportion to that on the roots, twigs, and leaves, some will think instinctive; some will refer it to an effort of nature to supply the necessary strength to enable the stem to resist the great strain of the winds upon the elevated top. If it take place to a greater extent than what arises from the greater elongation of the necessary vessels of communication, perhaps it is owing to the evaporation or stagnation of the sap on the tall exposed stem, and to the considerable motion or waving of the stem by wind promoting deposition, evincing one of the deep balancings of material cause and effect, or circumstantial regulation, which mocks the wisdom of the wise. We admit, also, that pruning, in the first place, impedes formation of flower-buds, and will sometimes thus prevent exhaustion of trees by seeding, which is so prejudicial both to the quality and quantity of the new wood deposit; but the consequent greater length of stem, greater exposure to evaporation, constriction of bark, and slenderer connecting tubes between leaf and roots, all tend subsequently to promote formation of flower-buds, although the removal of the lower branches may for a few seasons serve to {302} prevent this. We therefore consider pruning, excepting in a very slight degree, to guide to one leader, and to remove the sickly, lower, moss-covered branches a few seasons earlier than they would have dropped off in the common course of decay, to be generally preventive of quantity of wood-deposit, even of common marketable timber, in any considerable number of years, although pruning to a greater degree is often necessary where fine clean timber is required.
Our author’s next implied assumption, that a tree produces best timber in a soil and climate natural to it (we suppose by this is meant the soil and climate where the kind of tree is naturally found growing), is, we think, at least exceedingly hypothetical; and, judging from our facts, incorrect. The natural soil and climate of a tree, is often very far from being the soil and climate most suited to its growth, and is only the situation where it has greater power of occupancy, than any other plant whose germ is present. The pines do not cover the pine barrens of America, because they prefer such soil, or grow most luxuriant in such soil; they would thrive much better, that is, grow faster, in the natural allotment of the oak and the walnut, and also mature to a better wood in this deeper richer soil. But the {303} oak and the walnut banish them to inferior soil from greater power of occupancy in good soil, as the pines, in their turn, banish other plants from inferior sands—some to still more sterile location, by the same means of greater powers of occupancy in these sands. One cause considerably affecting the natural location of certain kinds of plants is, that only certain soils are suited to the preservation of certain seeds, throughout the winter or wet season. Thus many plants, different from those which naturally occupy the soil, would feel themselves at home, and would beat off intruders, were they once seated. We have had indubitable proof in this country, that Scots fir, grown upon good deep loam, and strong till (what our author would call the natural soil of the oak), is of much better quality, and more resinous, than fir grown on poor sand (what he would call the natural soil of the Scots fir), although of more rapid growth on the loam than on the sand; and the best Scots fir we have ever seen, of equal age and quickness of growth, is growing upon Carse land (clayey alluvium).