1much as it ran before; ſo that when the water ſhall be quadru
ple, the height ſhall be double; and if the water were centuple,
the height would be decuple onely, and ſo from one quantity
to another: And on the contrary, in the Diverſions; If of the
100. parts of water that run thorow a River, there ſhall be di
verted 19/160, the height of the River diminiſheth onely 1/10, and con
tinuing to divert 17/100, the height of the River abateth likewiſe 1/10,
and ſo proceeding to divert 15/100 and then 13/100, and then 11/100, and
then 9/100, and then 7/100, and then 5/100, and then 3/106, alwaies by
each of theſe diverſions, the height of the Running Water di
miniſheth the tenth part: although that the diverſions be ſo une.
qual. Reflecting I ſay upon this infallible Truth, I have had a
conceit, that though the Reno and other Rivers were diverted
from the Valleyes, and there was onely left the Chanel of Navi
gation, which was onely the 1/20 part of the whole water that fal
leth into the Valleys; yet nevertheleſs, the water in thoſe ſame
Valleyes would retain a tenth part of that height that became
conjoyned by the concourſe of all the Rivers: And therefore I
ſhould think that it were the beſt reſolution to maintain the Gha
nel of Navigation (if it were poſſible) continuate unto the Po of
Ferrara, and from thence to carry it into the Po of Volano; for
beſides that it would be of very great eaſe in the Navigation of
Bologna, and Ferrara, the ſaid water would render the Po oſ
Volano navigable as far as to the very Walls of Ferrara, and con
ſequently the Navigation would be continuate from Bologna to
the Sea-ſide.
ple, the height ſhall be double; and if the water were centuple,
the height would be decuple onely, and ſo from one quantity
to another: And on the contrary, in the Diverſions; If of the
100. parts of water that run thorow a River, there ſhall be di
verted 19/160, the height of the River diminiſheth onely 1/10, and con
tinuing to divert 17/100, the height of the River abateth likewiſe 1/10,
and ſo proceeding to divert 15/100 and then 13/100, and then 11/100, and
then 9/100, and then 7/100, and then 5/100, and then 3/106, alwaies by
each of theſe diverſions, the height of the Running Water di
miniſheth the tenth part: although that the diverſions be ſo une.
qual. Reflecting I ſay upon this infallible Truth, I have had a
conceit, that though the Reno and other Rivers were diverted
from the Valleyes, and there was onely left the Chanel of Navi
gation, which was onely the 1/20 part of the whole water that fal
leth into the Valleys; yet nevertheleſs, the water in thoſe ſame
Valleyes would retain a tenth part of that height that became
conjoyned by the concourſe of all the Rivers: And therefore I
ſhould think that it were the beſt reſolution to maintain the Gha
nel of Navigation (if it were poſſible) continuate unto the Po of
Ferrara, and from thence to carry it into the Po of Volano; for
beſides that it would be of very great eaſe in the Navigation of
Bologna, and Ferrara, the ſaid water would render the Po oſ
Volano navigable as far as to the very Walls of Ferrara, and con
ſequently the Navigation would be continuate from Bologna to
the Sea-ſide.
But to manage this enterprize well, it is neceſſary to meaſure
the quantity of the Water that the Rivers diſcharge into the Val
leys, and that which the Chanel of Navigation carryeth, in man
ner as I have demonſtrated at the beginning of this Book; for this
once known, we ſhall alſo come to know, how profitable this di
verſion of the Chanel of Navigation from the Valleys is like to
prove; which yet would ſtill be unprofitable, if ſo be that all
the Rivers that diſcharge their waters into the Valleys, ſhould
not ſirſt be Drained, according to what hath been above ad
vertiſed.
the quantity of the Water that the Rivers diſcharge into the Val
leys, and that which the Chanel of Navigation carryeth, in man
ner as I have demonſtrated at the beginning of this Book; for this
once known, we ſhall alſo come to know, how profitable this di
verſion of the Chanel of Navigation from the Valleys is like to
prove; which yet would ſtill be unprofitable, if ſo be that all
the Rivers that diſcharge their waters into the Valleys, ſhould
not ſirſt be Drained, according to what hath been above ad
vertiſed.
Abbot CASTELLI, in the preſent conſideration referring
himfelf to the Relation of Monſig. Corſini, grounded upon the Ob
ſervations and Precepts of the ſaid Abbot; as is ſeen in the pre
ſent Diſcourſe. I thought it convenient for the compleating of the
Work of our Aulhour, upon theſe ſubjects, to inſert it in this
place.
himfelf to the Relation of Monſig. Corſini, grounded upon the Ob
ſervations and Precepts of the ſaid Abbot; as is ſeen in the pre
ſent Diſcourſe. I thought it convenient for the compleating of the
Work of our Aulhour, upon theſe ſubjects, to inſert it in this
place.