Chapter XXIX

_That planting Aquatics upon Banks in the Fenns, will preserve and
strengthen them, so as to render them more able to resist the Force of
a Flood._

What will be asserted in this Chapter is not the Result of Surmise, but is what I have been an Eye Witness of. Be it known then unto all those, who think proper to do this Book so much Honour as to give it a Perusal, that the Author is a Fenman: Why should he be ashamed of his Native Country? A Country, where they have Inverted the following Lines of Horace:

_Omne cum Proteus pecus egit altos_
_Visere Montes:_
_Piscium & summâ genus hæsit Ulmo,_
_Nota quæ sedes fuerat columbis,_
_Et superjecto pavidæ natarunt_
_Æquore Dammæ._

For here, instead of those Places which were the Habitations of Doves, being visited by Fish, just the contrary has happened. By the Ingenuity of these People, barren Sands, over which Ships used to ride at Anchor, are changed into pleasant Meadows and rich Inclosures.

Having now shewn how much of a Fenman we are, it will be proper to return to the Subject.

There can be no Doubt, but that every Attempt which is made to promote the Improvement of Agriculture, is highly commendable; and on the other Hand, it is the Duty of every one, to endeavour to rectify such of those Attempts as he knows, as well from his own Experience, as from the Conversation of skilful Engineers, to be erroneous: And we are sorry to say, we are very clear that the Scheme of planting Aquatics upon Banks in the Fenns, notwithstanding what has been affirmed about it, is so far from being likely to strengthen such Banks, that it is a certain Way to destroy them.

In order to make some of our Readers, who live in the high Country, sensible of the Truth of what will be here asserted, it will be necessary to explain the Nature of Fenn-Draining, which shall be done in as few Words as possible.

Water is a Fluid, as has been before observed; and it is the Nature of a Fluid to be always endeavouring to restore an Equilibrium in it's Parts, which we may observe by it's restless Motion after the Surface of it is made uneven. It is in order to restore this Equilibrium, that Water rushes down with such Rapidity, from the high Country into the Fenns; where, when it has got, the Surface of the whole Country being even, and in general no higher than the Bottom of the adjacent Seas, it remains quiet; Fenn-Draining, therefore, must be a Work of Art.--Now let us examine into the Principles of this Art.

The first Thing to be done is, to scour out the Bottoms of the Rivers, which run through them, from Sand and Filth, and by that Means to make a good Outfall; then to make Banks of Earth on the Sides of those Rivers, to prevent, as much as possible, the Water which comes down in a Flood from overflowing the Country, as well as to retain such Water as shall be thrown into the Rivers by Engines. It will be needless here to describe the Machinery of a Water Engine; it will be sufficient to say, that Drains are cut which lead from these Engines to the Rivers, which Drains are banked likewise, and that these Engines, by the Help of the Wind, have a Power of Drawing the Water from the Lands which are drowned, into these Drains, till they are quite full, and till the Water has got to a Level which is higher than the Bottom of the adjacent Sea; and by the Principles of Hydrostatics is forced to run into the Sea to restore the Equilibrium: It is by the Strength of the Banks, the Force of the Engines, and the Goodness of the Outfall, that a Fenn must be drained. Now, I affirm that planting Aquatics upon Banks in the Fenn will not strengthen them, but destroy them.

All Vermin in a Fenn are fond of a Bank; it is high Ground, and therefore dry and comfortable for them in the Winter, for which Reason they are always full of Moles, and particular Kinds of Rats and Mice, with long Noses, call'd Field Mice and Rats, and abundance more Animals, which breed incessantly; and make Holes and Burrows through the Banks in all Directions. One Kind of these Rats builds his House so commodious, that it is worth while to relate the Ingenuity of this little Free Mason: He begins by making a Hole in the Top of the Bank, and after a Labyrinth of many Windings and Turnings, he finishes all, by making another towards the Bottom of the Bank close to the Water's Edge; by that Means he extends his Territories from the Top of the Bank to the Bottom, and has a Supply of fresh Water, without being seen by the Enemy, who is continually upon the Watch for him. Owls, Buzzards, Kites, Ravens, Carrion Crows, and other Birds of Prey in the Fenn, always frequent the Banks in the Evening, and if the Grass is kept low by Cattle, they will destroy most of the Vermin upon them.

But then we must not plant Trees upon them, as they will be the finest Cover imaginable for those Rats; Trees will not only hide them from the Sight of the Birds of Prey, but will likewise hinder those Birds from darting down upon them when they have got a Sight of them.

I remember, near eighteen Years ago, several Sorts of Aquatics were planted upon the Banks in the Fenns near Thorney-Abbey; the Consequence was, the Roots of the Trees served for Timber for the Houses of these Vermin, and the Branches were a Shelter from the Birds of Prey, by which Means they were full of Holes, thro' which the Water used to run back again to the Lands as fast as the Engines threw it out; for which Reason the Trees were ordered to be grubbed up, by the principal Engineer.

There is nothing which strengthens a Bank like a good Covering of Grass, close eat by Cattle; for if once Water penetrates through the outside Coat of a Bank, it is not in the Power of Aquatics to hinder it from tearing the Earth away with it. If Aquatics are planted any where, they ought to be at some Distance _before_ the Bank, in order to keep the Lash of Water from wearing it away.

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