1aforementioned Caſes, and in the preſent one that we are in hand
with, there have, in times paſt, very groſſe Errours been com
mitted, through the not having ever well underſtood the true
meaſure of Running waters; and here it is to be noted, that the
buſineſſe is, that in Venice, the diverſion of the waters of the
Lake, by diverting the Brent was debated, and in part executed,
without conſideration had how great abatement of water might
follow in the Lake, if the Brent were diverted, as I have ſhewn
in the firſt Conſideration upon this particular, from which act
there hath inſued very bad conſequences, not only the difficulty
of Navigation, but it hath infected the wholſomneſſe of the Air,
and cauſed the ſtoppage of the Ports of Venice. And on the
contrary, the ſame inadvertency of not conſidering what riſing of
the Water the Reno, and other Rivers being opened into the Val
leys of Bologna and Ferrara, might cauſe in the ſaid Valleys, is
the certain cauſe that ſo many rich and fertile Fields are drown
ed under water, converting the happy habitations and dwellings
of men into miſerable receptacles for Fiſhes: Things which
doubtleſſe would never have happened, if thoſe Rivers had been
kept at their height, and Reno had been turn'd into Main-Po,
and the other Rivers into that of Argenta, and of Volano. Now
there having ſufficient been ſpoken by the above-named Monſig.
Corſini in his Relation, I will only adde one conceit of my own,
which after the Rivers ſhould be regulated, as hath been ſaid, I
verily believe would be of extraordinary profit, I much doubt in
deed that I ſhall finde it a hard matter to perſwade men to be of
my mind, but yet nevertheleſs I will not queſtion, but that thoſe,
at leaſt, who ſhall have underſtood what I have ſaid and demon
ſtrated concerning the manners and proportions, according to
which the abatements and riſings of Running waters proceed,
that are made by the Diverſions and Introductions of Waters,
will apprehend that my conjecture is grounded upon Reaſon.
And although I deſcend not to the exactneſſe of particulars, I
will open the way to others, who having obſerved the requiſite
Rules of conſidering the quantity of the waters that are intro
duced, or that happen to be diverted, ſhall be able with punctu
ality to examine the whole buſineſſe, and then reſolve on that
which ſhall be expedient to be done.
with, there have, in times paſt, very groſſe Errours been com
mitted, through the not having ever well underſtood the true
meaſure of Running waters; and here it is to be noted, that the
buſineſſe is, that in Venice, the diverſion of the waters of the
Lake, by diverting the Brent was debated, and in part executed,
without conſideration had how great abatement of water might
follow in the Lake, if the Brent were diverted, as I have ſhewn
in the firſt Conſideration upon this particular, from which act
there hath inſued very bad conſequences, not only the difficulty
of Navigation, but it hath infected the wholſomneſſe of the Air,
and cauſed the ſtoppage of the Ports of Venice. And on the
contrary, the ſame inadvertency of not conſidering what riſing of
the Water the Reno, and other Rivers being opened into the Val
leys of Bologna and Ferrara, might cauſe in the ſaid Valleys, is
the certain cauſe that ſo many rich and fertile Fields are drown
ed under water, converting the happy habitations and dwellings
of men into miſerable receptacles for Fiſhes: Things which
doubtleſſe would never have happened, if thoſe Rivers had been
kept at their height, and Reno had been turn'd into Main-Po,
and the other Rivers into that of Argenta, and of Volano. Now
there having ſufficient been ſpoken by the above-named Monſig.
Corſini in his Relation, I will only adde one conceit of my own,
which after the Rivers ſhould be regulated, as hath been ſaid, I
verily believe would be of extraordinary profit, I much doubt in
deed that I ſhall finde it a hard matter to perſwade men to be of
my mind, but yet nevertheleſs I will not queſtion, but that thoſe,
at leaſt, who ſhall have underſtood what I have ſaid and demon
ſtrated concerning the manners and proportions, according to
which the abatements and riſings of Running waters proceed,
that are made by the Diverſions and Introductions of Waters,
will apprehend that my conjecture is grounded upon Reaſon.
And although I deſcend not to the exactneſſe of particulars, I
will open the way to others, who having obſerved the requiſite
Rules of conſidering the quantity of the waters that are intro
duced, or that happen to be diverted, ſhall be able with punctu
ality to examine the whole buſineſſe, and then reſolve on that
which ſhall be expedient to be done.
Reflecting therefore upon the firſt Propoſition, that the
Riſings of a Running Water made by the acceſſion of new water
into the River, are to one another, as the Square-Roots of the
quantity of the water that runneth; and conſequently, that the
ſame cometh to paſs in the Diverſions: Inſomuch, that a River
running in height one ſuch a certain meaſure, to make it encreaſe
double in height, the water is to be encreaſed to three times as
Riſings of a Running Water made by the acceſſion of new water
into the River, are to one another, as the Square-Roots of the
quantity of the water that runneth; and conſequently, that the
ſame cometh to paſs in the Diverſions: Inſomuch, that a River
running in height one ſuch a certain meaſure, to make it encreaſe
double in height, the water is to be encreaſed to three times as
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