_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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