|CHAPTER XVIII. |
Those vegetables commonly sown in our fields, require a middle degree of both, not being able to live on the sides of perpendicular walls in hot countries, nor under water in cold ones, neither are they amphibious, but must have a surface of earth not covered, nor much soaked with water, which deprives them of their necessary degree of heat, and causes them to languish. The symptoms of their disease are a pale or yellow colour in their leaves, and a cessation of growth, and death ensues as sure as from a dropsy.
The only remedy to prevent this disease in plants, is to lay such wet land up into ridges, that the water may run off into the furrows, and be conveyed by ditches or drains into some river.
The more a soil is filled with water, the less heat it will have.
The two sorts of land most liable to be over-glutted with water, are hills, whereof the upper stratum (or staple) is mould lying upon a second stratum of clay. And generally all strong deep land.
Hills are made wet and spewy by the rain-water which falls thereon, and soaks into them as into other land ; but being stopped by the clay lying next the surface or staple, cannot enter the clay ; and, for want of entrance, spreads itself upon it ; and as water naturally tends downwards, it is by the incumbent mould, partly stopped in its descent, from the upper, towards the lower side of an
hill ; and being followed and pressed on by more water from above, is forced to rise up into the mould lying upon it, which it fills as a cistern does a fountain (or jette d'eau). The land of such a hill is not the less wet or spewy for being laid up in ridges, if they be made from the higher to the lower part of the field ; for the force of the water's weight continued, will raise it so, as to cause it to issue out at the very tops of those ridges : the earth becomes a sort of pap or batter, and being like a quagmire, in going over it, the feet of men and cattle sink in till they come to the clay ; the upper mould is near the condition of the chaos instabilis terra.
There are two methods of draining such a wet hill : the one is to dig many trenches across the hill horizontally, and either fill them up with stones, loose or arch-wise, through which the water, when it soaks into the trenches, may run off at one or both ends of them into some ditch which is lower, and caries it away : then they cover the trenches with mould, and plough over them as in dry level ground.
For if they are made with the descent, and not across it, then they will be parallel to the rills of water than run upon the surface of the clay under the staple (or upper stratum of mould) and would be no more effectual for draining the hill, than the digging of one river parallel to another, without joining it in any part, would be effectual for draining the other river of its water.
This method has been found effectual for a time, but not of long continuance ; for the trenches are apt to be stopped up, and then the springs break out again as before ; besides, this is a very chargeable work, and in many places the expense of it may almost equal the purchase of the land.
Therefore it is a better method to plough the ridges across the hill, almost horizontally, that their parting furrows lying open, may
each serve as a drain to the ridge next below it ; for when the plough has made the bottom of these horizontal furrows a few inches deeper than the surface of the clay, the water will run to their ends, very securely, without rising into the mould, provided no part of the furrows be lower than their ends.
These parting furrows, and their ridges, must be made more or less oblique, according to the form and declivity of the hill ; but the more horizontal they are, the sooner the rain-water will run off the lands ; for in that case it will run to the furrows, and reach them at right angles, which it will not do when the ridges (of lands) are oblique ; and therefore the water's course across the lands will be longer. Every one of these horizontal trenches receives all the water from the rills or little gutters wherein the water runs betwixt the mould and the clay ; these are all cut off by the trenches, which receive the water at their upper sides, and carry it away, as the trunks of lead placed under the eaves of a house do carry away the rain-water.
The natural course of water being downwards, it would always run by the nearest way to the bottom of the hill, if nothing stopped it ; but the water runs from a hill in two manners, viz., upon the surface of the staple, and upon the surface of the clay that is under the staple : that which runs under keeps its straight course from the top to the bottom of a hill, under a ridge that is made exactly with the descent of the hill, except that part of the water that rises up into the mould, and a very little that soaks into the furrows ; for when the furrows are not made exactly with the descent, the more oblique they are to the descent, the longer will be the water's course under the ridges ; and the shorter, as they are nearer being at right angles to the descent. It is also the same with the water that falls upon the surface of the ridges, for the more horizontal they are, the shorter its course will be from them to the furrows which carry it
off ; and the less of the water will sink into the ridges, the less oblique and the nearer to right angles to the descent they are made.
If there were no other manner of ploughing ridges on the sides of hills than what is commonly practised on the plains, this method of leaving open furrows (or drains on declivities) would be impracticable ; because the plough could not turn up the furrows against the hill, and against the ridge also, from the lower side of it : but the easy remedy against that inconvenience is, to plough such ridges in pairs, without throwing any earth into the trenches, and then the ridges will be plain at top, and the rain-water will run speedily downward to the next trench, and thence to the head-land, and so out of the field. These trenches will be made, as well as kept, always open, by this ploughing in pairs, and is abundantly more easy than the way of ploughing ridges singly. This ploughing in pairs prevents also another inconveniency, which would otherwise happen to those horizontal ridges ; and that is, they being highest in the middle, the rain-water could not run freely from the upper half of a ridge towards the next furrow below it, but would be apt to sink in there, and soak through the ridge ; but when ridges lie in pairs, the water will run off from a whole ridge, as well as of the lower half of a ridge that is ploughed singly, and highest in the middle.
Note, that every time of ploughing, the pairs must be changed, so that the furrow, which had two lands (or ridges) turned towards it one time, must have two turned from it the nest time : this method keeps the surfaces of all the ridges (or lands) pretty near even*.
* Note, this cannot be done on a hill, whose declivity is so great, that the plough is not able to turn a furrow against it. But in this case, perhaps, it may be sufficient to plough the ridges obliquely, enough for the furrow to be turned both ways.
Farmers are at more trouble and pains to drown such land (it being common to break their horses' wind in ploughing up hill) than they would be at, if they laid their ridges in the above said manner, which would effectually make them dry. Many hundred acres of good ground are spoiled ; and many a good horse, in ploughing against the hill, and against all reason, demonstration, and experience too, which might be learned even from the Irish, who drain their bogs and make them fruitful, whilst some English bestow much labour to drown and make barren many of their hills, which would more easily be made dry and fertile.
I have observed, that those places of such a hill, that when ploughed with the descent were the wettest, and never produced any thing that was sown on them, became the very richest, when made dry by ploughing across the descent. This shows that water does not impoverish land, but the contrary ; though, whilst it stands thereon, it prevents the heat which is necessary to the production of most sorts of vegetables : and where it runs swiftly, it carries much earth away with it ; where it runs slowly, it deposits, and leaves much behind it.
Though, in all places where this way of making the ridges across the descent of the hills is practised, the land becomes dry, yet very few farmers will alter their old method ; no, not even to try the experiment ; but still complain their ground is so wet and spewy, that it brings them little or no profit : and if the year prove moist, they are great losers by sowing it*.
* Remember, in making ridges of all sorts, and of whatsoever figure the piece is, that no ridge ought to have any more furrows at one end, than at the other end ; for if there be, the plough must be turned in the middle of the piece, which will cause the land to be trodden by the horses ; but if each end have an equal number of furrows, the horses, in turning, will tread only upon the head-lands, which may be ploughed afterwards ; or if designed to be horse-hoed, the head-lands should be narrow, and not ploughed at all.
Of such force is that precept of Virgil's, Cultusque, habitusque, locorum (prędiscere), that seldom is the prejudice of it removed by reason : but some of late are convinced, by observing that a hill of mine has been made dry by this means for fourteen years past, which before was always more wet and spewy than any field in the neighbourhood, and from the time of enclosing it out of a heath (or common) and the converting it to arable, which was about seventy years ago, it has been reputed as little better than barren, on account of its wetness ; and that it has been the most profitable field of my farm ever since it has been under this new management. I have also another field that lies about a mile and a half from me ; it doth not belong to the farm were I live, but was thrown upon my hands, no tenant caring to rent it, because a great part of it was full of springs and barren ; this also having been kept in lands ploughed across the descent (which is but a small declivity) is become dry : and now the most prejudiced farmers agree, that keeping the lands or ridges of wet ground always cross the descent doth cure its spewyness. Hereupon some have attempted to put this method in practice on their wet land, and after it had been well tilled up hill and down, have ploughed it the last time for sowing of wheat, in flat lands across the descent ; but, by mismanagement, their furrows are higher at each end than the middle, so that none of the water can run off either downwards or sideways, or any other way.
Had the furrows carried off the water at both or either of their ends, it might have been effectual notwithstanding the broad lands, because their ground hath a much less declivity, and is much less spewy than my hill was : they will doubtless find their mistake and amend it, having a precedent before their eyes ; but, if they had none within their own inspection, I question whether this mismanagement might not discourage them from prosecuting their project any further.
The benefit of laying up strong deep land into ridges, is very
great ; though there be no springs in it, as are in the hills aforementioned.
This land, when it lies flat, and is ploughed in the Virgilian manner, sometimes one way, sometimes the other, by cross-ploughing, retains the rain-water a long time soaking into it ; by that misfortune, the plough is kept out two or three weeks longer than if the same were in round ridges ; nay, sometimes its flatness keeps it from drying till the season of ploughing, and even of sowing too, be lost.
The reasons commonly given against such ridges, are these following :
I. They prevent the fancied benefit of cross ploughing.
II. Farmers think they lose part of their ground, by leaving more furrows betwixt ridges than when they lay their land flat, where the lands are made much larger than round ridges can conveniently be : and because, also, the furrows betwixt ridges must be broader, and lie open ; but the other they fill up by the harrows.
The first of these I have already answered elsewhere, by showing, that cross-ploughing is oftener injurious than beneficial.
What I mean by gaining of ground, is the increasing of the earth's surface ; for if a flat piece be ploughed into ridges, and if in each sixteen feet breadth there be an empty furrow of two feet, and yet by the height and roundness of the ridges, they have eighteen feet of surface, capable of producing corn equally to eighteen feet, whilst the piece was flat, there will be one-eighth part of profitable ground, or surface, gained more than it had when level ; and this, I believe, experience will prove, if the thing were well examined into.
But against this increase of profitable ground there is an objection which I must not call a frivolous one, in respect to the authors who bring it ; yet I hope the desire of finding the truth, will justify me to examine it, and the arguments brought to sustain it.
This opinion of theirs is founded upon their notion (which I think very erroneous) of the perpendicular growth of vegetables, and is, by Mr. Bradley, set in its best light, in his Volume I. page 8, usque ad page 13, and in his cuts, representing three hills ; but his arguments seem to be such as all arguments are which pretend to prove a thing to be what it is not viz., sophistical ones.
The hypothesis he endeavours to prove, is in page 8, thus: " A hill may contain four equal sides, which meet in a point at the top ; but the contents of these four sides can produce no more, either of grain or trees, than the plain ground upon which the hill stands or has its base ; and yet by the measure of the sides, we find twice the number of acres, roods, and poles, which measures in the base or ground-plot" ; and therefore, page 9, " hills are worth no more than half their superficial measure, i. e., two acres upon the side of the hill to pay as much as one upon the plain, provided the soil of both is equally rich."
To prove it he gives an example in figure 3, of buildings upon a hill ; showing that the two sides of the hill will only bear the same number of houses that may stand in the line at the base.
This is foreign to the question of how much grain or how many trees the hill will produce. For vegetables being fed by the earth, require much more of its surface to nourish them than is necessary for them to stand on ; but buildings require no more of the surface but room to stand on ; therefore, no such argument, taken from buildings, can be applied to vegetables.
This argument of Mr. Bradley's gives no more satisfaction to the question about producing of vegetables, than a grazier would do, being asked how many oxen a certain pasture-ground would maintain, if he should answer, by satisfying you with the number of churches which might stand thereon.
The like answer, in effect, may be given to the argument in Fig. IV. of the pales, only he has forgot to show, that to mound over the hill would require double the rails, or double the hedge-wood (except stakes) as to mound the base ; if it did not, the hill would be yet of the more value, because thereon more surface might be fenced in at less expense.
In fig. II. he gives no good reason why the hill should not bear twice the number of trees as the base can do ; for there is as much room for two hundred trees on the hill, as for one hundred on the base, because he allows the surface to be double to that of the base. He ought to measure the distances of the trees on the hill, by a line parallel to the surface they grow on, as well as he does the distances of those below.
And I suppose the row at the base, together with the surface they grow on, were raised up so that is should become parallel to half the row on the hill, would not the trees in the base row be twice as near to one another as the trees in the hill row are ? And suppose a line had been tied from the tops of all the lower trees before the row was so raised up at one end, and then, after the situation of the row was so altered, if by this line the trees should be pulled from being perpendicular to the surface they grow on, and made to stand oblique to that, and perpendicular to the horizon, as the upper trees are, would the distances of the trees from one another be altered by this change of posture ? No ; for their bottoms would be at the same distances, because not removed ; and their tops,
because the same line holds them, at the same distances in both postures.
Mr. Bradley's lines, drawn from the trees below, which are one perch asunder, make the two rows of threes, falsely, seem to be at equal distances, because these lines are parallel to each other : but this is a deceit ; for in truth, the distances of the trees are not meassured by the distances of those lines, but by the extreme points at the ends of the lines* ; and those two points above, where the lines cut the row obliquely, and at unequal angles, are twice as far asunder as the endmost or extreme points below are, where the lines cut the row at right angles. Hence may be inferred that there is room for twice as many trees to grow on the hill as on the base, and twice as much grain, for the same reason, and because there is twice the surface for the roots to spread in. And since Mr. Bradley allows the hill to contain two perches to one of the base, and the soil of both to be of equal goodness, and he yet affirms, that the two can produce no more of grain or trees than the one perch can, I cannot see why it should not be as reasonable to say, that two quarters of oats will maintain a horse no longer, nor better, than one quarter of oats, of equal goodness will do.
* These upper trees are measured by the unequal length of the lines, not by their parallel distance, as the lower trees are ; therefore his measure is a quibble.
In page 13, he concludes thus : " That hills, in their measure, contain only as much profitable land as the plain or plot of ground they stand upon ; and as a proof of that, all vegetables or plants have an erect method of growth.
This proof of Mr. Bradley's is funded upon an argument which has no consequence, unless it were first proved that the surface of earth could produce and maintain as many vegetables or plants as could stand thereon in an erect posture ; which supposition is as impossible, as that half an acre should produce and maintain a hecatomb, without Mr. Bradley's teaching oxen to live upon air for their food, as he thinks Van Helmont's tree did.
All expert husbandmen must needs be convinced, that the greatest crop of vegetables that ever grew, might stand in an erect posture, upon a twentieth (and I may say the hundredth) part of the surface that produced it ; therefore, there must be nineteen parts (for the roots to spread) unoccupied by the trunks, stems, or stalks.
And though it be true, that a hill will support no more of these (than its base) when placed in an erect posture close together, as in a sheaf ; yet this close position is only proper for them when they are dead, and require no more nourishment than houses and pales do ; and consequently require no room but to stand on. Therefore, this argument of Mr. Bradley's must not be admitted in vegetative growth, where there is always required nineteen times more room in the surface, for the use of the roots, than what the stems, trunks, or stalks, do possess upon it ; and the more room there is for roots, the greater number of plants may be produced.
Neither can I admit, that all vegetables or plants have an erect method of growth ; because the contrary is seen in camomile, and divers other vegetables, which have an horizontal method of growth.
But what is more material to this purpose, to be observed, is, that all vegetables have horizontal roots, and roots parallel to the earth's surface or superficies ; and unless those roots have a sufficient superficies of earth to range in, for nourishment of a plant, the stem and branches cannot prosper, whatever be their method of growth
above the earth ; and if there be not a due quantity of food for the roots, within the earth, a very little space may contain the external parts of vegetables upon it.
From what has been said, I think we may conclude, that Mr. Bradley's hill may produce more vegetables than the base whereon it stands ; and, therefore, it is of more value than half its superficial measure, i. e., two acres on the hill is worth more than one acre on the plain, the soil being equally rich, as he allows it to be, in his case.
Now, indeed, whether Mr. Bradley might not possibly be deceived in his opinion, of the equal richness of his hill and his plain, I will not dispute ; I will only say this, that it is generally otherwise. But where a plain is ploughed up into moderate ridges, their height being in proportion to the depth of the staple, below which the plough must take nothing into the ridges, the soil is equally rich, whether it be ploughed plain or ridged up. and, as the surface is in the ridges increased, there is nothing, in all Mr. Bradley's arguments, that shows, why that increased surface should not produce more vegetables than the same earth could do whilst it was level.
There are other reasons why it should produce more when ridges, besides the increase of surface, as,
I. It is then more free from the injuries of too much water.
II. It is better protected against cold winds ; because the ridges are a shelter to one another.
III. If the surface be much exhausted, by too frequent sowing, the ridges may be made just where the furrows were, and then the surface will be entirely changed.
To the three we may add a forth reason, viz., the raising the thickness of the staple in the ridges, keeping the surface drier in wet weather, and moister at the bottom of the staple in dry weather. And I have seen barley that was drilled on my raised little ridges flourish in a dry summer on the brow of my chalky hill, and on my lowest land in wet weather when the barley hand-sown contiguous to it on each side those ridges, sown on the level the same day that the ridges were drilled, have looked yellow and sickly, and yet it is not wet land.
The following general rules ought to be observed about ridges, viz.,
That as to their height, regard must be had to the nature of the soil, in its difficult admission of water ; for the greater that is, the greater declivities the ridges should have ; and then, if the soil be not deep, they should generally be made the narrower.
There is one thing which Mr. bradley takes no notice of, viz, that no more of the rain, or other benefits of the atmosphere, which descend perpendicularly, can fall on a hill, or on a ridge, than what would fall on the base, or ground-plot. But, it is probable, that more of the fine vapour, which swims in the current of the air horizontally, does strike and break against those eminences, and so make an equivalent* ; except that is runs off more quickly.
* But though ridges do alter or increase the surface, the quantity of soil or earth remaining the same as on the level, and of no greater depth than can be tilled, it may produce equal crops of corn with the level, and no more ; except from the advantages the ridges may give it in lying drier.
Notwithstanding all I have here said, in behalf of ridges, I must confess, that for my hoeing-husbandry, I should prefer land that is naturally dry enough, without a necessity of being laid up in any larger or higher ridges than what may contain six feet in breadth, that size being the largest that is proper for the regular operation of the horse-hoe ; whether the rows be double, triple, or quadruple.
Since the printing of my Essay, I find upon trial that these narrow ridges are as effectual as any for carrying the water off from my clayey hill ; and that they may be made much less horizontal than broad ridges, whereby their furrows are the more easily turned upwards against the declivity
I have not tried any narrower ridges than of six feet, upon this
hill ; but I have had full experience of five feet and of tour feet ridges upon other land, and find that all sizes of these narrow ridges are very advantageous even where the crop is to be sown upon the level ; for fewer furrows are necessary for the tilling of an acre, when it is kept in such ridges, than in broad lands, and after wet weather the ridges will be fit to be ploughed much sooner than level ground.