1the fury of the South, and South-Weſt-Winds carryed ſuch
abundance of ſand into the Mouth, or Out-let of Fiume morto,
that it wholly ſtopt it up: eſpecially when the waters on Piſa
ſide were low and ſhallow, And they think, that turning the
Lake of Fiume morto into Serchio, and the Serchio maintaining
continually its own Mouth with the force of its waters open to the
Sea, and conſequently alſo Fiume morto, they would have had the
Out-let clear and open; and in this manner they think, that the
Plain of Piſa would have been freed from the waters. The bu
ſineſs paſſeth for current, at firſt ſight; but experience proveth
the contrary, and Reaſon confirmeth the ſame: For the height
of the water of thoſe Plains, was regulated by the height of the
waters in the Mouth of Fiume morto; that is, The waters at the
Mouth being high, the waters alſo do riſe in the fields; and when
the waters at the Mouth are low, the waters of the fields do like
wiſe abate: Nor is it enough to ſay, That the Out-let or Vent
of Fiume morto is continual, but it muſt be very low: Now if
Fiume morto did determine in Serchio, it is manifeſt that it
would determine high; for Serchio terminating in the Sea, when
ever it more and more aboundeth with water, and riſeth, it is ne
ceſlary that alſo Fiume morto hath its level higher, and conſe
quently ſhall keep the waters in the Plains higher. Nay, it hath
happened ſometimes (and I ſpeak it upon my own ſight) that
Fiume morto hath reverſed its courſe upwards towards Piſa;
which caſe will ever happen, whenſoever the Piſan waters chance
to be lower than the level of thoſe of Serchio; for in that caſe
the waters of Serchio return back upon the Plains thorow Fiume
morto in ſuch ſort, that the Muddineſſes, and the Serchio have
been obſerved to be carried by this return as farr as the Walls of
Piſa; and then before ſuch time as ſo great waters can be aſ
ſwaged, which come in with great fury, and go out by little and
little, there do paſs very many days, and moneths, nay ſome
times one being never able to find the waters of Serchio,
when at the ſhalloweſt, ſo low as the Sea in level; (which is the
loweſt place of the waters) it thence doth follow, that the wa
ters of Fiume morto ſhould never at any time of the year, ſo long
as they determine in Serchio, be ſo low, as they come to be when
the ſame Fiume morto determineth in the Sea. Tis true indeed,
that the Mouth of Fiume morto, opened into the Sea, is ſubject to
the inconvenience of being ſtopt up by the force of Winds: But
in this caſe, it is neceſſary to take ſome pains in opening it; which
may eaſily be done, by cutting that Sand a little which ſtayeth
in the Mouth, after that the Wind is laid; and it is enough if you
make a Trench little more than two Palms in breadth; for the
water once beginning to run into it, it will in a few hours carry
abundance of ſand into the Mouth, or Out-let of Fiume morto,
that it wholly ſtopt it up: eſpecially when the waters on Piſa
ſide were low and ſhallow, And they think, that turning the
Lake of Fiume morto into Serchio, and the Serchio maintaining
continually its own Mouth with the force of its waters open to the
Sea, and conſequently alſo Fiume morto, they would have had the
Out-let clear and open; and in this manner they think, that the
Plain of Piſa would have been freed from the waters. The bu
ſineſs paſſeth for current, at firſt ſight; but experience proveth
the contrary, and Reaſon confirmeth the ſame: For the height
of the water of thoſe Plains, was regulated by the height of the
waters in the Mouth of Fiume morto; that is, The waters at the
Mouth being high, the waters alſo do riſe in the fields; and when
the waters at the Mouth are low, the waters of the fields do like
wiſe abate: Nor is it enough to ſay, That the Out-let or Vent
of Fiume morto is continual, but it muſt be very low: Now if
Fiume morto did determine in Serchio, it is manifeſt that it
would determine high; for Serchio terminating in the Sea, when
ever it more and more aboundeth with water, and riſeth, it is ne
ceſlary that alſo Fiume morto hath its level higher, and conſe
quently ſhall keep the waters in the Plains higher. Nay, it hath
happened ſometimes (and I ſpeak it upon my own ſight) that
Fiume morto hath reverſed its courſe upwards towards Piſa;
which caſe will ever happen, whenſoever the Piſan waters chance
to be lower than the level of thoſe of Serchio; for in that caſe
the waters of Serchio return back upon the Plains thorow Fiume
morto in ſuch ſort, that the Muddineſſes, and the Serchio have
been obſerved to be carried by this return as farr as the Walls of
Piſa; and then before ſuch time as ſo great waters can be aſ
ſwaged, which come in with great fury, and go out by little and
little, there do paſs very many days, and moneths, nay ſome
times one being never able to find the waters of Serchio,
when at the ſhalloweſt, ſo low as the Sea in level; (which is the
loweſt place of the waters) it thence doth follow, that the wa
ters of Fiume morto ſhould never at any time of the year, ſo long
as they determine in Serchio, be ſo low, as they come to be when
the ſame Fiume morto determineth in the Sea. Tis true indeed,
that the Mouth of Fiume morto, opened into the Sea, is ſubject to
the inconvenience of being ſtopt up by the force of Winds: But
in this caſe, it is neceſſary to take ſome pains in opening it; which
may eaſily be done, by cutting that Sand a little which ſtayeth
in the Mouth, after that the Wind is laid; and it is enough if you
make a Trench little more than two Palms in breadth; for the
water once beginning to run into it, it will in a few hours carry