1the variety of the velocities of the ſaid Water importeth, and the
knowledge of them is neceſſary to conclude the true quantity of
the running Water, we ſhall finde it manifeſt, that the benefit of
this Vent is far leſſe than it is generally thought: And mereover,
we ſhall finde, if I deceive not my ſelf, that there follow from
thence ſo many miſchiefs, that I could greatly incline to believe,
that it were more to the purpoſe wholly to ſtop it up, than to
maintain it open: yet I am not ſo wedded to my opinion, but
that I am ready to change my judgement upon ſtrength of better
reaſons; eſpecially of one that ſhall have firſt well underſtood
the beginning of this my diſcourſe, which I frequently inculcate,
becauſe its abſolutely impoſſible without this advertiſement to
treat of theſe matters, and not commit very great errours.
knowledge of them is neceſſary to conclude the true quantity of
the running Water, we ſhall finde it manifeſt, that the benefit of
this Vent is far leſſe than it is generally thought: And mereover,
we ſhall finde, if I deceive not my ſelf, that there follow from
thence ſo many miſchiefs, that I could greatly incline to believe,
that it were more to the purpoſe wholly to ſtop it up, than to
maintain it open: yet I am not ſo wedded to my opinion, but
that I am ready to change my judgement upon ſtrength of better
reaſons; eſpecially of one that ſhall have firſt well underſtood
the beginning of this my diſcourſe, which I frequently inculcate,
becauſe its abſolutely impoſſible without this advertiſement to
treat of theſe matters, and not commit very great errours.
I propoſe therefore to conſideration, that although it be true,
that whilſt the water of the main Po is at its greateſt height, the
Bank and Dam then cut of the Po of Ferara, and the ſuperior
waters having a very great fall into the Channel of Ferara, they
precipitate into the ſame with great violence and velocity, and
with the ſame in the beginning, or little leſſe, they run towards
the Po of Volana, and of Argenta on the ſea coaſts; yet after the
ſpace of ſome few hours, the Po of Ferara being full, and the ſu
perior Waters not finding ſo great a diclivity there, as they had
at the beginning of the cutting, they fall not into the ſame with
the former velocity, but with far leſſe, and thereby a great deal
leſſe Water begins to iſſue from the great Po; and if we dili
gently compare the velocity at the firſt cutting, with the velocity
of the Water after the cutting made, and when the Po of Ferara
ſhall be full of Water, we ſhall finde perhaps that to be fifteen or
twenty times greater than this, and conſequently the Water
which iſſues from the great Po, that firſt impetuoſity being paſt,
ſhall be onely the fifteenth or twentieth part of that which iſſued
at the beginning; and therefore the Waters of the main Po will
return in a ſmall time almoſt to the firſt height. And here I will
pray thoſe who reſt not wholly ſatisfied with what hath been ſaid,
that for the love of truth, and the common good, they would
pleaſe to make diligent obſervation whether in the time of great
Floods, the ſaid Bank or Dam at Bondeno is cut, and that in few
hours the main Po diminiſheth, as hath been ſaid about a foot in
its height; that they would obſerve I ſay, whether, a day or two
being paſt, the Waters of the main Po return almoſt to their firſt
height; for if this ſhould follow, it would be very clear, that the
benefit which reſulteth from this diverſion or Vent, is not ſo great
as is univerſally preſumed; I ſay, it is not ſo great as is
preſumed; becauſe, though it be granted for true, that
the Waters of the main Po, abate at the beginning of
that whilſt the water of the main Po is at its greateſt height, the
Bank and Dam then cut of the Po of Ferara, and the ſuperior
waters having a very great fall into the Channel of Ferara, they
precipitate into the ſame with great violence and velocity, and
with the ſame in the beginning, or little leſſe, they run towards
the Po of Volana, and of Argenta on the ſea coaſts; yet after the
ſpace of ſome few hours, the Po of Ferara being full, and the ſu
perior Waters not finding ſo great a diclivity there, as they had
at the beginning of the cutting, they fall not into the ſame with
the former velocity, but with far leſſe, and thereby a great deal
leſſe Water begins to iſſue from the great Po; and if we dili
gently compare the velocity at the firſt cutting, with the velocity
of the Water after the cutting made, and when the Po of Ferara
ſhall be full of Water, we ſhall finde perhaps that to be fifteen or
twenty times greater than this, and conſequently the Water
which iſſues from the great Po, that firſt impetuoſity being paſt,
ſhall be onely the fifteenth or twentieth part of that which iſſued
at the beginning; and therefore the Waters of the main Po will
return in a ſmall time almoſt to the firſt height. And here I will
pray thoſe who reſt not wholly ſatisfied with what hath been ſaid,
that for the love of truth, and the common good, they would
pleaſe to make diligent obſervation whether in the time of great
Floods, the ſaid Bank or Dam at Bondeno is cut, and that in few
hours the main Po diminiſheth, as hath been ſaid about a foot in
its height; that they would obſerve I ſay, whether, a day or two
being paſt, the Waters of the main Po return almoſt to their firſt
height; for if this ſhould follow, it would be very clear, that the
benefit which reſulteth from this diverſion or Vent, is not ſo great
as is univerſally preſumed; I ſay, it is not ſo great as is
preſumed; becauſe, though it be granted for true, that
the Waters of the main Po, abate at the beginning of