1more than it did at the level AF, it would riſe yet more above
the ſaid level A F; although that the ſelf ſame quantity of water
runneth all the while. By the above-named ſolid Principle I
reſolve extravagant Problems in my Treatiſe, and aſſign the Rea
ſons of admirable effects of Running Waters: But as for what
concerneth our purpoſe of the Pontine Fenns, we have the Cau
ſes very plain and clear; for which, by the trampling of Cattle
which paſs thorow the Draining River, the waters abate ſo nota
bly, that it is as it were a miracle for thoſe Reeds, Flags, and
Weeds that ſpring up, encreaſe, and ſpread all over the River,
ſtop and impede that velocity of the waters which they would
have by means of their declivity. But that paſſage of thoſe Beaſts,
treading down thoſe Weeds unto the bottom of the River, in ſuch
ſort, as that they no longer hinder the Current of the Water;
and the ſame Waters increaſing in their courſe, they do dimi
niſh in meaſure and height; and by this meanes the Ditches of the
Plains empty into the ſame ſucceſsfully, and leave them free
from Waters, and Drained. But theſe Weeds in a ſhort
time ſprouting up anew, and raiſing their ſtalkes thorow the
body of the Waters, they reduce things to the ſame evil
ſtate, as before, retarding the velocity of the Water, ma
king it to increaſe in height, and perhaps do occaſion grea
ter miſchiefs; ſeeing that thoſe many knots which each plant
ſhoots forth, begets a greater multitude of Stalks, which much
more incumbering the Water of the River, are a greater impe
diment unto its velocity, and conſequently make the height
of the waters to encreaſe ſo much the more, and do more miſchief
than before.
the ſaid level A F; although that the ſelf ſame quantity of water
runneth all the while. By the above-named ſolid Principle I
reſolve extravagant Problems in my Treatiſe, and aſſign the Rea
ſons of admirable effects of Running Waters: But as for what
concerneth our purpoſe of the Pontine Fenns, we have the Cau
ſes very plain and clear; for which, by the trampling of Cattle
which paſs thorow the Draining River, the waters abate ſo nota
bly, that it is as it were a miracle for thoſe Reeds, Flags, and
Weeds that ſpring up, encreaſe, and ſpread all over the River,
ſtop and impede that velocity of the waters which they would
have by means of their declivity. But that paſſage of thoſe Beaſts,
treading down thoſe Weeds unto the bottom of the River, in ſuch
ſort, as that they no longer hinder the Current of the Water;
and the ſame Waters increaſing in their courſe, they do dimi
niſh in meaſure and height; and by this meanes the Ditches of the
Plains empty into the ſame ſucceſsfully, and leave them free
from Waters, and Drained. But theſe Weeds in a ſhort
time ſprouting up anew, and raiſing their ſtalkes thorow the
body of the Waters, they reduce things to the ſame evil
ſtate, as before, retarding the velocity of the Water, ma
king it to increaſe in height, and perhaps do occaſion grea
ter miſchiefs; ſeeing that thoſe many knots which each plant
ſhoots forth, begets a greater multitude of Stalks, which much
more incumbering the Water of the River, are a greater impe
diment unto its velocity, and conſequently make the height
of the waters to encreaſe ſo much the more, and do more miſchief
than before.
Another head to which theſe harms may be reduced, but pro
ceeding from the ſame Root, which hath a great part in this
diſorder, is the impediment of thoſe Wears in the River which
are made by heightning the bed of the ſame, for placing of fiſh
ing-nets; of which Piſcaries I reckoned above ten, when I made
a voyage thorow thoſe waters to Sandolo. And theſe Fiſhing
Wears are ſuch impediments, that ſome one of them makes the
water of the River in the upper part to riſe half a Palm, and
ſometimes a whole Palm, and more; ſo that when they are all
gathered together, theſe impediments amount to more than ſeven,
or poſſibly than eight Palms.
ceeding from the ſame Root, which hath a great part in this
diſorder, is the impediment of thoſe Wears in the River which
are made by heightning the bed of the ſame, for placing of fiſh
ing-nets; of which Piſcaries I reckoned above ten, when I made
a voyage thorow thoſe waters to Sandolo. And theſe Fiſhing
Wears are ſuch impediments, that ſome one of them makes the
water of the River in the upper part to riſe half a Palm, and
ſometimes a whole Palm, and more; ſo that when they are all
gathered together, theſe impediments amount to more than ſeven,
or poſſibly than eight Palms.
There concurreth for a third moſt Potent Cauſe of the waters
continuing high in the evacuating, or Draining Chanel, and con
ſequently on the Plains; The great abundance of water that iſſu
eth from Fiume Siſto, the waters of which do not keep within its
Banks when they are abundant; but encreaſing above its Chanel,
they unite with thoſe of the Evacuator, and diſperſing thorow
continuing high in the evacuating, or Draining Chanel, and con
ſequently on the Plains; The great abundance of water that iſſu
eth from Fiume Siſto, the waters of which do not keep within its
Banks when they are abundant; but encreaſing above its Chanel,
they unite with thoſe of the Evacuator, and diſperſing thorow
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