The Earth As Modified By Human Action Part 24

The growth of arboreal vegetation is comparatively slow, and we are often told that, though he who buries an acorn may hope to see it shoot up to a miniature resemblance of the majestic tree which shall shade his remote descendants, yet the longest life hardly embraces the seedtime and the harvest of a forest. The planter of a wood, it is said, must be actuated by higher motives than those of an investment, the profits of which consist in direct pecuniary gain to himself or even to his posterity; for if, in rare cases, an artificial forest may, in a generation or two, more than repay its original cost, still, in general, the value of its timber will not return the capital expended and the interest accrued. [Footnote: According to Clave (Etudes, p. 159), the net revenue from the forests of the state in France, making no allowance for interest on the capital represented by the forest, is two dollars per acre. In Saxony it is about the same, though the cost of administration is twice as much as in France; in Wurtemberg it is about a dollar an acre; and in Prussia, where half the income is consumed in the expenses of administration, it sinks to less than half a dollar.

This low rate in Prussia and other German states is partly explained by the fact that a considerable proportion of the annual product of the wood is either conceded to persons claiming prescriptive rights, or sold, at a very small price, to the poor. Taking into account the capital invested in forest-land, and adding interest upon it, Pressler calculates that a pine wood, managed with a view to felling it when eighty years old, would yield one-eighth of one per cent. annual profit; a fir wood, at one hundred years, one-sixth of one per cent.; a beech wood, at one hundred and twenty years, one-fourth of one per cent. The same author gives the net income of the New Forest in England, over and above expenses, interest not computed, at twenty-five cents per acre only. In America, where no expense is bestowed upon the woods, the value of the annual growth has generally been estimated much higher.

Forest-trees are often planted in Europe for what may be called an early crop. Thus in Germany acorns are sown and the young seedlings cultivated like ordinary field-vegetables, and cut at the age of a very few years for the sake of the bark and young twigs used by tanners. In England, trees are grown at the rate of two thousand to the acre, and cut for props in the mines at the diameter of a few inches. Plantations for hoop-poles, and other special purposes requiring small timber, would, no doubt, often prove high remunerative.] But the modern improved methods of sylviculture show vastly more favorable financial results; and when we consider the immense collateral advantages derived from the presence of the forest, the terrible evils necessarily resulting from its destruction, we cannot but admit that the preservation of existing woods, and the more costly extension and creation of them where they have been unduly reduced or have never existed, are among the plainest dictates of self-interest and most obvious of the duties which this age owes to those that are to come after it.

Financial Results of Forest Plantation.

Upon the whole, I am persuaded that the financial statistics which are found in French and German authors, as the results of European experience in forest economy, present the question under a too unfavorable aspect; and therefore these calculations ought not to discourage landed proprietors from making experiments on this subject.

These statistics apply to woods whose present condition is, in an eminent degree, the effect of previous long-continued mismanagement; and there is much reason to believe that in the propitious climate of the United States new plantations, regulated substantially according to the methods of De Courval, Chambrelent, and Chevandier, and accompanied with the introduction of exotic trees, as, for example, the Australian caruarina and eucalyptus [Footnote: Although the eucalyptus thrives admirably in Algeria--where it attains a height of from fifty to sixty feet, and a diameter of fifteen or sixteen inches, in six years from the seed--and in some restricted localities in Southern Europe, it will not bear the winters even of Florence, and consequently cannot be expected to flourish in any part of the United States except the extreme South and California. The writer of a somewhat enthusiastic article on this latter State, in Harper's Monthly for July, 1872, affirms that he saw a eucalyptus "eight years from a small cutting, which was seventy-five feet in height, and two feet and a half in diameter at the base."

The paulownia, which thrives in Northern Italy, has a wood of little value, but the tree would serve well as a shelter for seedlings and young plants of more valuable species, and in other cases where a temporary shade is urgently needed. The young shoots, from a stem polled the previous season, almost surpa.s.s even the eucalyptus in rapidity of growth. Such a shoot from a tree not six inches in diameter, which I had an opportunity of daily observing, from the bursting out of the bud from the bark of the parent stem in April till November of the same year, acquired in that interval a diameter of between four and five inches and a height of above twenty feet.] which, latter, it is said, has a growth at least five, and, according to some, ten times more rapid than that of the oak--would prove good investments even in an economical aspect.

[Footnote: The economical statistics of Grigor, Arboriculture, Edinburgh, 1868, are very encouraging. In the preface to that work the author says: "Having formed several large plantations nearly forty years ago, which are still standing, in the Highlands of Scotland, I can refer to them as, after paying every expense, yielding a revenue equal to that of the finest arable land in the country, where the ground previously to these formations was not worth a s.h.i.+lling an acre." See also Hartig, Ueber den Wachsthumsgang und Ertrag der Buche, Eiche und Kiefer, 1869, and especially Bryant, Forest Trees, chap. ix.]

There is no doubt that they would pay the expenses of their planting at no distant period, at least in every case where irrigation is possible, and in very many situations, terraces, ditches, or even horizontal furrows upon the hillsides, would answer as a subst.i.tute for more artificial irrigation. Large proprietors would receive important indirect benefits from the shelter and the moisture which forests furnish for the lands in their neighborhood, and eventually from the acc.u.mulation of vegetable mould in the woods. [Footnote: The fertility of newly cleared land is by no means due entirely to the acc.u.mulation of decayed vegetable matter on its surface, and to the decomposition of the mineral const.i.tuents of the soil by the gases emitted by the fallen leaves. Sachs has shown that the roots of living plants exercise a most powerful solvent action on rocks, and hence stones are disintegrated and resolved into elements of vegetable nutrition, by the chemical agency of the forest, more rapidly than by frost, rain, and other meteorological influences.] The security of the investment, as in the case of all real-estate, is a strong argument for undertaking such plantations, and a moderate amount of government patronage and encouragement would be sufficient to render the creation of new forests an object of private interest as well as of public advantage, especially in a country where the necessity is so urgent and the climate so favorable as in the United States.

Instability of American Life.

All human inst.i.tutions, a.s.sociate arrangements, modes of life, have their characteristic imperfections. The natural, perhaps the necessary defect of ours, is their instability, their want of fixedness, not in form only, but even in spirit. The face of physical nature in the United States shares this incessant fluctuation, and the landscape is as variable as the habits of the population. It is time for some abatement in the restless love of change which characterizes us, and makes us almost a nomade rather than a sedentary people. [Footnote: It is rare that a middle-aged American dies in the house where he was born, or an old man even in that which he has built; and this is scarcely less true of the rural districts, where every man owns his habitation, than of the city, where the majority live hired houses. This life of incessant flitting is unfavorable for the execution of permanent improvements of every sort, and especially of those which, like the forest, are slow in repaying any part of the capital expended in them. It requires a very generous spirit in a landholder to plant a wood on a farm he expects to sell, or which he knows will pa.s.s out of the hands of his descendants at his death. But the very fact of having begun a plantation would attach the proprietor more strongly to the soil for which he had made such a sacrifice; and the paternal acres would have a greater value in the eyes of a succeeding generation, if thus improved and beautified by the labors of those from whom they were inherited. Landed property, therefore, the transfer of which is happily free from every legal impediment or restriction in the United States, would find, in the feelings thus prompted, a moral check against a too frequent change of owners, and would tend to remain long enough in one proprietor or one family to admit of gradual improvements which would increase its value both to the possessor and to the state.] We have now felled forest enough everywhere, in many districts far too much. Let us restore this one element of material life to its normal proportions, and devise means of maintaining the permanence of its relations to the fields, the meadows, and the pastures, to the rain and the dews of heaven, to the springs and rivulets with which it waters the earth. The establishment of an approximately fixed ratio between the two most broadly characterized distinctions of rural surface--woodland and ploughland--would involve a certain persistence of character in all the branches of industry, all the occupations and habits of life, which depend upon or are immediately connected with either, without implying a rigidity that should exclude flexibility of accommodation to the many changes of external circ.u.mstance which human wisdom can neither prevent nor foresee, and would thus help us to become, more emphatically, a well-ordered and stable commonwealth, and, not less conspicuously, a people of progress.

CHAPTER IV.

THE WATERS.

Land Artificially won from the Waters--Great Works of Material Improvement--Draining of Lincolns.h.i.+re Fens--Incursions of the Sea in the Netherlands--Origin of Sea-dikes--Gain and Loss of Land in the Netherlands--Marine Deposits on the Coast of Netherlands--Draining of Lake of Haarlem--Draining of the Zuiderzee--Geographical Effects of Improvements in the Netherlands--Ancient Hydraulic Works--Draining of Lake Celano by Prince Torlonia--Incidental Consequences of draining Lakes--Draining of Marshes--Agricultural Draining--Meteorological Effects of Draining--Geographical Effects of Draining--Geographical Effects of Aqueducts and Ca.n.a.ls--Antiquity of Irrigation--Irrigation in Palestine, India, and Egypt--Irrigation in Europe--Meteorological Effects of Irrigation--Water withdrawn from Rivers for Irrigation--Injurious Effects of Rice-culture--Salts Deposited by Water of Irrigation--Subterranean Waters--Artesian Wells--Artificial Springs--Economizing Precipitation--Inundations in France--Basins of Reception--Diversion of Rivers--Glacier Lakes--River Embankments--Other Remedies against Inundations--Dikes of the Nile--Deposits of Tuscan Rivers--Improvements in Tuscan Maremma--Improvements in Val di Chiana--Coast of the Netherlands.

Land artificially won from the Waters.

Man, as we have seen, has done much to revolutionize the solid surface of the globe, and to change the distribution and proportions, if not the essential character, of the organisms which inhabit the land and even the waters. Besides the influence thus exerted upon the life which peoples the sea, his action upon the land has involved a certain amount of indirect encroachment upon the territorial jurisdiction of the ocean.

So far as he has increased the erosion of running waters by the destruction of the forest or by other operations which lessen the cohesion of the soil, he has promoted the deposit of solid matter in the sea, thus reducing the depth of marine estuaries, advancing the coast-line, and diminis.h.i.+ng the area covered by the waters. He has gone beyond this, and invaded the realm of the ocean by constructing within its borders wharves, piers, light-houses, breakwaters, fortresses, and other facilities for his commercial and military operations; and in some countries he has permanently rescued from tidal overflow, and even from the very bed of the deep, tracts of ground extensive enough to const.i.tute valuable additions to his agricultural domain. The quant.i.ty of soil gained from the sea by these different modes of acquisition is, indeed, too inconsiderable to form an appreciable element in the comparison of the general proportion between the two great forms of terrestrial surface, land and water; but the results of such operations, considered in their physical and their moral bearings, are sufficiently important to ent.i.tle them to special notice in every comprehensive view of the relations between man and nature.

There are cases, as on the western sh.o.r.es of the Baltic, where, in consequence of the secular elevation of the coast, the sea appears to be retiring; others, where, from the slow sinking of the land, it seems to be advancing. These movements depend upon geological causes wholly out of our reach, and man can neither advance nor r.e.t.a.r.d them. [Footnote: It is possible that the weight of the sediment let fall at the mouths of great rivers, like the Ganges, the Mississippi, and the Po, may cause the depression of the strata on which they are deposited, and hence if man promotes the erosion and transport of earthy material by rivers, he augments the weight of the sediment they convey into their estuaries, and consequently his action tends to accelerate such depression. There are, however, cases where, in spite of great deposits of sediment by rivers, the coast is rising. Further, the manifestation of the internal heat of the earth at any given point is conditioned by the thickness of the crust at such point. The deposits of rivers tend to augment that thickness at their estuaries. The sediment of slowly-flowing rivers emptying into shallow seas is spread over so great a surface that we can hardly imagine the foot or two of slime they let fall over a wide area in a century to form an element among even the infinitesimal quant.i.ties which compose the terms of the equations of nature. But some swift rivers, rolling mountains of fine earth, discharge themselves into deeply scooped gulfs or bays, and in such cases the deposit amounts, in the course of a few years, to a ma.s.s the transfer of which from the surface of a large basin, and its acc.u.mulation at a single point, may be supposed to produce other effects than those measurable by the sounding-line. Now, almost all the operations of rural life, as I have abundantly shown, increase the liability of the soil to erosion by water. Hence, the clearing of the valley of the Ganges, for example, by man, must have much augmented the quant.i.ty of earth transported by that river to the sea, and of course have strengthened the effects, whatever they may be, of thickening the crust of the earth in the Bay of Bengal.

In such cases, then, human action must rank among geological influences.

To the geological effects of the thickening of the earth's crust in the Bay of Bengal, are to be added those of thinning it on the highlands where the Ganges rises. The same action may, as a learned friend suggests to me, even have a cosmical influence. The great rivers of the earth, taken as a whole, transport sediment from the polar regions in an equatorial direction, and hence tend to increase the equatorial diameter, and at the same time, by their inequality of action, to a continual displacement of the centre of gravity, of the earth. The motion of the globe, and of all bodies affected by its attraction, is modified by every change of its form, and in this case we are not authorized to say that such effects are in any way compensated.]

There are also cases where similar apparent effects are produced by local oceanic currents, by river deposit or erosion, by tidal action, or by the influence of the wind upon the waves and the sands of the seabeach. A regular current may drift suspended earth and seaweed along a coast until they are caught by an eddy and finally deposited out of the reach of further disturbance, or it may scoop out the bed of the sea and undermine promontories and headlands; a powerful river, as the wind changes the direction of its flow at its outlet, may wash away sh.o.r.es and sandbanks at one point to deposit their material at another; the tide or waves, stirred to unusual depths by the wind, may gradually wear down the line of coast, or they may form shoals and coast-dunes by depositing the sand they have rolled up from the bottom of the ocean.

These latter modes of action are slow in producing effects sufficiently important to be noticed in general geography, or even to be visible in the representations of coast-line laid down in ordinary maps; but they nevertheless form conspicuous features in local topography, and they are attended with consequences of great moment to the material and the moral interests of men. The forces which produce these limited results are all in a considerable degree subject to control, or rather to direction and resistance, by human power, and it is in guiding, combating, and compensating them that man has achieved some of his most remarkable and most honorable conquests over nature. The triumphs in question, or what we generally call harbor and coast improvements, whether we estimate their value by the money and labor expended upon them, or by their bearing upon the interests of commerce and the arts of civilization, must take a very high rank among the great works of man, and they are fast a.s.suming a magnitude greatly exceeding their former relative importance.

The extension of commerce and of the military marine, and especially the introduction of vessels of increased burden and deeper draught of water, have imposed upon engineers tasks of a character which a century ago would have been p.r.o.nounced, and, in fact, would have been, impracticable; but necessity has stimulated au ingenuity which has contrived means of executing them, and which gives promise of yet greater performance in time to come.

Indeed, although man, detached from the solid earth, is almost powerless to struggle against the sea, he is fast becoming invincible by it so long as his foot is planted on the sh.o.r.e, or even on the bottom of the rolling ocean; and though on some battle-fields between the waters and the land he is obliged slowly to yield his ground, yet he retreats still facing the foe, and will finally be able to say to the sea, "Thus far shalt thou come and no farther, and here shall thy proud waves be stayed!" [Footnote: It is, nevertheless, remarkable that in the particular branch of coast engineering where great improvements are most urgently needed, comparatively little has been accomplished. I refer to the creation of artificial harbors, and of facilities for loading and discharging s.h.i.+ps. The whole coast of Italy is, one may almost say, harborless and even, wharfless, and there are many thousands of miles of coast in rich commercial countries in Europe, where vessels can neither lie in safety for a single day, nor even, in better protected heavens, s.h.i.+p or land their pa.s.sengers or cargoes except by the help of lighters, and other not less clumsy contrivances. It is strange that such enormous inconveniences are borne with so little effort to remove them, and especially that break-waters are rarely constructed by Governments except for the benefit of the military marine.]

Great Works of Material Improvement.

Men have ceased to admire the vain exercise of power which heaped up the great pyramid to gratify the pride of a despot with a giant sepulchre; for many great harbors, many important lines of internal communication, in the civilized world, now exhibit works which in volume and weight of material surpa.s.s the vastest remains of ancient architectural art, and demand the exercise of far greater constructive skill and involve a much heavier pecuniary expenditure than would now be required for the building of the tomb of Cheops. It is computed that the great pyramid, the solid contents of which when complete were about 3,000,000 cubic yards, could be erected for a million of pounds sterling. The breakwater at Cherbourg, founded in rough water sixty feet deep, at an average distance of more than two miles from the sh.o.r.e, contains double the ma.s.s of the pyramid, and many a comparatively unimportant ca.n.a.l has been constructed at twice the cost which would now build that stupendous monument.

The description of works of harbor and coast improvement which have only an economical value, not a true geographical importance, does not come within the plan of the present volume, and in treating this branch of my subject, I shall confine myself to such as are designed either to gain new soil by excluding the waters from grounds which they had permanently or occasionally covered, or to resist new encroachments of the sea upon the land. [Footnote: Some notice of great works executed by man in foreign lands, and probably not generally familiar to my readers, may, however, prove not uninteresting.

The desaguadero, or ca.n.a.l constructed by the Viceroy Revillagigedo to prevent the inundation of the city of Mexico by the lakes in its vicinity, besides subsidiary works of great extent, has a cutting half a mile long, 1,000 feet wide, and from 150 to 200 feet deep.--Hoffmann, Encyclopaedie, art. Mexico.

The adit which drains the mines of Gwennap in Cornwall, with its branches, is thirty miles long. Those of the silver mines of Saxony are scarcely less extensive, and the Ernst-August-Stollen, or great drain of the mines of the Harz, is fifteen miles long.

The excavation for the Suez Ca.n.a.l were computed at 75,000,000 cubic metres, or about 100,000,000 cubic yards, and those of the Ganges Ca.n.a.l, which, with its branches, had a length of 3,000 miles, amount to nearly the same quant.i.ty.

The quarries at Maestricht have undermined a s.p.a.ce of sixteen miles by six, or more than two American towns.h.i.+ps, and the catacombs of Rome, in part, at least, originally quarries, have a lineal extent of five hundred and fifty miles. The catacombs of Paris required the excavation of 13,000,000 cubic yards of stone, or more than four times the volume of the great pyramid.

The excavation for the Mt. Cenis tunnel, eight miles in length, wholly through solid rock, amounted to more than 900,000 cubic yards, and 16,000,000 of brick were employed for the lining.

In an article on recent internal improvements in England, in the London Quarterly Review for January, 1858, it is stated that in a single rock-cutting on the Liverpool and Manchester railway, 480,000 cubic yards of stone were removed; that the earth excavated in the construction of English railways up to that date amounted to a hundred and fifty million cubic yards, and that at the Round Down Cliff, near Dover, a single blast of nineteen thousand pounds of powder blew down a thousand million tons of chalk, and covered fifteen acres of land with the fragments.

In 1869, a ma.s.s of marble equal to one and a half times the cubical contents of the Duomo at Florence, or about 450,000 cubic yards, was thrown down at Carrara by one blast, and two hours after, another equal ma.s.s, which had been loosened by the explosion, fell of itself.

Zolfanelli, La Lunigiana, p. 43.

The coal yearly extracted from the mines of England averages not less than 100,000,000 tons. The specific gravity of British coal ranges from 1.20 to 1.35, and consequently we may allow a cubic yard to the ton. If we add the earth and rock removed in order to reach the coal, we shall have a yearly amount of excavation for this one object equal to more than thirty times the volume of the pyramid of Cheops. These are wonderful achievements of human industry; but the rebuilding of Chicago within a single year after the great fire--not to speak of the extraordinary material improvements previously executed at that city--surpa.s.ses them all, and it probably involved the expenditure of a sum of muscular and of moral energy which has never before been exerted in the accomplishment of a single material object, within a like period.]

Draining of Lincolns.h.i.+re Fens.

The draining of the Lincolns.h.i.+re fens in England, which has converted about 400,000 acres of marsh, pool, and tide-washed flat into ploughland and pasturage, is a work, or rather series of works, of great magnitude, and it possesses much economical, and, indeed, no trifling geographical, importance. Its plans and methods were, at least in part, borrowed from the example of like improvements in Holland, and it is, in difficulty and extent, inferior to works executed for the same purpose on the opposite coast of the North Sea, by Dutch, Frisie, and Low German engineers. The s.p.a.ce I can devote to such operations will be better employed in describing the latter, and I content myself with the simple statement I have already made of the quant.i.ty of worthless and even pestilential land which has been rendered both productive and salubrious in Lincolns.h.i.+re, by diking out the sea, and the rivers which traverse the fens of that country.

The almost continued prevalence of west winds upon both coasts of the German Ocean occasions a constant set of the currents of that sea to the east, and both for this reason and on account of the greater violence of storms from the former quarter, the English sh.o.r.es of the North Sea are less exposed to invasion by the waves than those of the Netherlands and the provinces contiguous to them on the north. The old Netherlandish chronicles are filled with the most startling accounts of the damage done by the irruptions of the ocean, from west winds or extraordinarily high tides, at times long before any considerable extent of seacoast was diked. Several hundreds of those terrible inundations are recorded, and in many of them the loss of human lives is estimated as high as one hundred thousand. It is impossible to doubt that there must be enormous exaggeration in these numbers; for, with all the reckless hardihood shown by men in braving the dangers and privations attached by nature to their birthplace, it is inconceivable that so dense a population as such wholesale destruction of life supposes could find the means of subsistence, or content itself to dwell, on a territory liable, a dozen times in a century, to such fearful devastation. There can be no doubt, however, that the low continental sh.o.r.es of the German Ocean very frequently suffered immense injury from inundation by the sea, and it is natural, therefore, that the various arts of resistance to the encroachments of the ocean, and, finally, of aggressive warfare upon its domain, and of permanent conquest of its territory, should have been earlier studied and carried to higher perfection in the latter countries, than in England, which had less to lose or to gain by the incursions or the retreat of the waters.

Indeed, although the confinement of swelling rivers by artificial embankments is of great antiquity, I do not know that the defence or acquisition of land from the sea by diking was ever practised on a large scale until systematically undertaken by the Netherlanders, a few centuries after the commencement of the Christian era. The silence of the Roman historians affords a strong presumption that this art was unknown to the inhabitants of the Netherlands at the time of the Roman invasion, and the elder Pliny's description of the mode of life along the coast which has now been long diked in, applies precisely to the habits of the people who live on the low islands and mainland flats lying outside of the chain of dikes, and wholly unprotected by embankments of any sort.

Origin of Sea-dikes.

It has been conjectured, and not without probability, that the causeways built by the Romans across the marshes of the Low Countries, in their campaigns against the Germanic tribes, gave the natives the first hint of the utility which might be derived from similar constructions applied to a different purpose. [Footnote: It has often been alleged by eminent writers that a part of the fens in Lincolns.h.i.+re was reclaimed by sea-dikes under the government of the Romans. I have found no ancient authority in support of this a.s.sertion, nor can I refer to any pa.s.sage in Roman literature in which sea-dikes are expressly mentioned otherwise than as walls or piers, except that in Pliny (Hist. Nat. x.x.xvi. 24), where it is said that the Tyrrhenian Sea was excluded from the Lucrino Lake by dikes. Dugdale, whose enthusiasm for his subject led him to believe that recovering from the sea land subject to be flooded by it, was of divine appointment, because G.o.d said: "Let the waters under the heavens be gathered together unto one place and let the dry land appear," unhesitatingly ascribes the reclamation of the Lincolns.h.i.+re fens to the Romans, though he is able to cite but one authority, a pa.s.sage in Tacitus's Life of Agricola which certainly has no such meaning, in support of the a.s.sertion.--History of Embankment and Drainage, 2d edition, 1772.] If this is so, it is one of the most interesting among the many instances in which the arts and enginery of war have been so modified as to be eminently promotive of the blessings of peace, thereby in some measure compensating the wrongs and sufferings they have inflicted on humanity. [Footnote: It is worth mentioning, as an ill.u.s.tration of the applicability of military instrumentalities to pacific art, that the sale of gunpowder in the United States was smaller during the late rebellion than before, because the war caused the suspension of many public and private improvements, in the execution of which great quant.i.ties of powder were used for blasting.

The same observation was made in France during the Crimean war, and it is alleged that, in general, not ten per cent. of the powder manufactured on either either side of the Atlantic is employed for military purposes.

The blasting for the Mount Cenis tunnel consumed gunpowder enough to fill more than 200,000,000 musket cartridges. It is a fact not creditable to the moral sense of modern civilization, that very many of the most important improvements in machinery and the working of metals have originated in the necessities of war, and that man's highest ingenuity has been shown, and many of his most remarkable triumphs over natural forces achieved, in the contrivance of engines for the destruction of his fellow-man. The military material employed by the first Napoleon has become, in less than two generations, nearly as obsolete as the sling and stone of the shepherd, and attack and defence now begin at distances to which, half a century ago, military reconnaissances hardly extended. Upon a partial view of the subject, the human race seems destined to become its own executioner--on the one hand, exhausting the capacity of the earth to furnish sustenance to her taskmaster; on the other, compensating diminished production by inventing more efficient methods of exterminating the consumer. At the present moment, at an epoch of universal peace, the whole civilized world with the happy exception of our own country, is devoting its utmost energies, applying the highest exercise of inventive genius, to the production of new engines of war; and the last extraordinary rise in the price of iron and copper is in great part due to the consumption of these metals in the fabrication of arms and armed vessels. The simple subst.i.tution of sheet-copper for paper and other materials in the manufacture of cartridges has increased the market-price of copper by a large percentage on its former cost.

But war develops great civil virtues, and brings into action a degree and kind of physical energy which seldom fails to awaken a new intellectual life in a people that achieves great moral and political results through great heroism and endurance and perseverance. Domestic corruption has destroyed more nations than foreign invasion, and a people is rarely conquered till it has deserved subjugation.] The Lowlanders are believed to have secured some coast and bay islands by ring-dikes and to have embanked some fresh-water channels, as early as the eighth or ninth century; but it does not appear that sea-dikes, important enough to be noticed in historical records, were constructed on the mainland before the thirteenth century. The practice of draining inland acc.u.mulations of water, whether fresh or salt, for the purpose of bringing under cultivation the ground they cover, is of later origin, and is said not to have been adopted until after the middle of the fifteenth century. [Footnote: Staring, Voormaals en Thans, p. 150.]

Gain and Loss of Land in the Netherlands.

The total amount of surface gained to the agriculture of the Netherlands by diking out the sea and by draining shallow bays and lakes, is estimated by Staring at three hundred and fifty-five thousand bunder or hectares, equal to eight hundred and seventy-seven thousand two hundred and forty acres, which is one-tenth of the area of the kingdom.

[Footnote: Idem, p. 163. Much the largest proportion of the lands so reclaimed, though for the most part lying above low-water tidemark, are at a lower level than the Lincolns.h.i.+re fens, and more subject to inundation from the irruptions of the sea.] In very many instances the dikes have been partially, in some particularly exposed localities totally, destroyed by the violence of the sea, and the drained lands again flooded. In some cases the soil thus painfully won from the ocean has been entirely lost; in others it has been recovered by repairing or rebuilding the dikes and pumping out the water. Besides this, the weight of the dikes gradually sinks them into the soft soil beneath, and this loss of elevation must be compensated by raising the surface, while the increased burden thus added tends to sink them still lower. "Tetens declares," says Kohl, "that in some places the dikes have gradually sunk to the depth of sixty or even a hundred feet." [Footnote: Die Inseln und Marschen der Herzogthamer Schleswig und Holstein, iii., p. 151.] For these reasons, the processes of dike-building have been almost everywhere again and again repeated, and thus the total expenditure of money and of labor upon the works in question is much greater than would appear from an estimate of the actual cost of diking-in a given extent of coast-land and draining a given area of water-surface. [Footnote: The purely agricultural island of Pelworm, off the coast of Schleswig, containing about 10,000 acres, annually expends for the maintenance of its dikes not less than L6,000 sterling, or nearly $30,000.--J. G. Kohl, Inseln und Marschen Schleswig's und Holstein's, ii., p. 394.

The original cost of the dikes of Pelworm is not stated. "The greatest part of the province of Zeeland is protected by dikes measuring 250 miles in length, the maintenance of which costs, in ordinary years, more than a million guilders [above $400,000] ... The annual expenditure for dikes and hydraulic works in Holland is from five to seven million guilders" [$2,000,000 to $2,800,000].--Wild, Die Niederlande, i., p. 62.

One is not sorry to learn that the Spanish tyranny in the Netherlands had some compensations. The great chain of ring-dikes which surrounds a large part of Zeeland is due to the energy of Caspar de Robles, the Spanish governor of that province, who in 1570 ordered the construction of these works at the public expense, as a subst.i.tute for the private embankments which had previously partially served the same purpose.--Wild, Die Niederlande, i., p. 62.]