1have begun concerning Water only for Drink
ing, and proceed afterwards to Canals for Na
vigation. Canals are either worked up with
Maſonry, or elſe are only Trenches dug. Tren
ches are of two Sorts, cut either through an
open Country, or through the Bowels of a Hill,
which is called a Mine or ſubterraneous Con
duit. In both theſe, when you meet with either
Stone, Chalk, or compact Earth that does not
imbibe the Water, you will have no Occaſion
for Maſonry; but where the Bottom or Sides of
the Canal are not ſound, then you muſt fortify
them. If you are obliged to carry your Canal
through the Heart of a Hill, you muſt obſerve
the Rules above laid down. In ſubterraneous
Conduits, at the Diſtance of every hundred
Foot, you ſhould open Ventiges like Wells for
tified according as the Nature of the Earth
through which you dig requires. I have ſeen
ſuch Ventiges in the Country of the Marſi near
Rome, where the Water falls into the ancient
Lake Fucinus (now called the Pie di Luco)
built very finely with burnt Brick, and of an
incredible Depth. 'Till the four hundred and
forty-firſt year after the building of the City,
there was no ſuch thing as an Aqueduct built
at Rome; but afterwards thoſe Works were
brought to ſuch a Pitch, that whole Rivers
were conveyed to it through the Air, and we
are told, that there were ſo many of them, that
every ſingle Houſe was abundantly ſupplied
with Water. At firſt they began with ſubter
raneous Conduits; which indeed had a great
many Conveniencies. This hidden Work was
leſs ſubject to Injuries and being expoſed neither
to the Severity of Froſts, nor to the ſcorching
Dog-day Sun brought the Water freſher and
cooler, nor could eaſily be deſtroyed or turned
away by Enemies that might happen to make
Inroads into the Country. Theſe Works were
afterwards brought to ſuch a Magnificence,
that in order to have high Jets of Water in their
Gardens and in their Bathes, they built vault
ed Aqueducts, in ſome Places above an hundred
and twenty Foot high, and carried on for above
threeſcore Miles together. From theſe too they
reaped Conveniencies. In ſeveral Places, and
particularly beyond the Tyber, the Water of
theſe Aqueducts ſerved to grind their Corn,
and upon their being deſtroyed by the Enemy,
they were forced to make Mills for that Pur
poſe in Ships. To this add, that by means of
this Plenty of Water the City was kept cleaner
and the Air made freſher and more wholeſome.
The Architects alſo added ſome ingenious In
ventions to ſhew the Hours of the Day to the
great Recreation of the Beholders, by the Con
trivance of ſome little moving Statues of Braſs,
placed in the Front of the Head of the Aque
duct, which repreſented the publick Games and
the Ceremony of the Triumph. At the ſame
Time, the Sound of muſical Inſtruments and
ſweet Voices was heard, which were cauſed by
the Motion of the Water. Theſe Aqueducts
were covered in with an Arch of a good Thick
neſs, to prevent the Water from being heated
by the Sun; and this Vault was plaiſtered on
the Inſide with ſuch a Compoſition as we have
formerly in this Book recommended for Floors,
to the Thickneſs of at leaſt ſix Inches. The
Parts of the ancient Aqueduct were theſe.
Joining to the Incile was the Septum; along
the Courſe of the Conduit were the Caſtella;
where any higher Ground interfered the Specus
was dug; laſtly, to the Head was annexed the
Calix. An ancient Lawyer gives us the fol
lowing Deſcription of theſe ſeveral Parts. An
Aqueduct is a Conduit for conveying Water to
a certain Place by means of a gentle Slope.
The Septum is a Flood-gate or Water-ſtop
made at the Sluice for letting the Water into
the Aqueduct. The Caſtella are Water-houſes
or Conduit-heads for the Reception of the
publick Water. The Specus is a Kind of Mill
dam dug in the Earth. The Calix is the End
or Mouth of the Aqueduct, which diſcharges
the Water. All theſe muſt be made of very
ſtout Work, the Bottom as ſtrong as poſſible,
the Plaiſtering tight and by no means ſubject
to crack. The Mouth of the Sluice muſt be
ſtopt with a Flood-gate, with which you may
ſhut out the Water when it happens to be tur
bid, and by means whereof you may have an
Opportunity to mend any Part of the Aque
duct which is decayed, without being prevent
ed by the Water; and this Flood-gate muſt
have a Grate of Braſs to it, that Water may
flow into the Aqueduct clearer and more re
fined, leaving behind it the Leaves, Boughs
and other Traſh that fall into it. At every
hundred Cubits muſt be either a Conduit-head,
or a Mill-dam twenty Foot broad, thirty long,
and fifteen deep below the Bottom of the Chan
nel; and theſe are made to the Intent that
thoſe Waters which either fall into the Aque
duct from the Earth, or are thrown into it too
violently, may have a Place to ſubſide below
the other Stream, which by that means will
have room to flow on more refined and clear.
The Mouth of the Aqueduct for diſcharging
ing, and proceed afterwards to Canals for Na
vigation. Canals are either worked up with
Maſonry, or elſe are only Trenches dug. Tren
ches are of two Sorts, cut either through an
open Country, or through the Bowels of a Hill,
which is called a Mine or ſubterraneous Con
duit. In both theſe, when you meet with either
Stone, Chalk, or compact Earth that does not
imbibe the Water, you will have no Occaſion
for Maſonry; but where the Bottom or Sides of
the Canal are not ſound, then you muſt fortify
them. If you are obliged to carry your Canal
through the Heart of a Hill, you muſt obſerve
the Rules above laid down. In ſubterraneous
Conduits, at the Diſtance of every hundred
Foot, you ſhould open Ventiges like Wells for
tified according as the Nature of the Earth
through which you dig requires. I have ſeen
ſuch Ventiges in the Country of the Marſi near
Rome, where the Water falls into the ancient
Lake Fucinus (now called the Pie di Luco)
built very finely with burnt Brick, and of an
incredible Depth. 'Till the four hundred and
forty-firſt year after the building of the City,
there was no ſuch thing as an Aqueduct built
at Rome; but afterwards thoſe Works were
brought to ſuch a Pitch, that whole Rivers
were conveyed to it through the Air, and we
are told, that there were ſo many of them, that
every ſingle Houſe was abundantly ſupplied
with Water. At firſt they began with ſubter
raneous Conduits; which indeed had a great
many Conveniencies. This hidden Work was
leſs ſubject to Injuries and being expoſed neither
to the Severity of Froſts, nor to the ſcorching
Dog-day Sun brought the Water freſher and
cooler, nor could eaſily be deſtroyed or turned
away by Enemies that might happen to make
Inroads into the Country. Theſe Works were
afterwards brought to ſuch a Magnificence,
that in order to have high Jets of Water in their
Gardens and in their Bathes, they built vault
ed Aqueducts, in ſome Places above an hundred
and twenty Foot high, and carried on for above
threeſcore Miles together. From theſe too they
reaped Conveniencies. In ſeveral Places, and
particularly beyond the Tyber, the Water of
theſe Aqueducts ſerved to grind their Corn,
and upon their being deſtroyed by the Enemy,
they were forced to make Mills for that Pur
poſe in Ships. To this add, that by means of
this Plenty of Water the City was kept cleaner
and the Air made freſher and more wholeſome.
The Architects alſo added ſome ingenious In
ventions to ſhew the Hours of the Day to the
great Recreation of the Beholders, by the Con
trivance of ſome little moving Statues of Braſs,
placed in the Front of the Head of the Aque
duct, which repreſented the publick Games and
the Ceremony of the Triumph. At the ſame
Time, the Sound of muſical Inſtruments and
ſweet Voices was heard, which were cauſed by
the Motion of the Water. Theſe Aqueducts
were covered in with an Arch of a good Thick
neſs, to prevent the Water from being heated
by the Sun; and this Vault was plaiſtered on
the Inſide with ſuch a Compoſition as we have
formerly in this Book recommended for Floors,
to the Thickneſs of at leaſt ſix Inches. The
Parts of the ancient Aqueduct were theſe.
Joining to the Incile was the Septum; along
the Courſe of the Conduit were the Caſtella;
where any higher Ground interfered the Specus
was dug; laſtly, to the Head was annexed the
Calix. An ancient Lawyer gives us the fol
lowing Deſcription of theſe ſeveral Parts. An
Aqueduct is a Conduit for conveying Water to
a certain Place by means of a gentle Slope.
The Septum is a Flood-gate or Water-ſtop
made at the Sluice for letting the Water into
the Aqueduct. The Caſtella are Water-houſes
or Conduit-heads for the Reception of the
publick Water. The Specus is a Kind of Mill
dam dug in the Earth. The Calix is the End
or Mouth of the Aqueduct, which diſcharges
the Water. All theſe muſt be made of very
ſtout Work, the Bottom as ſtrong as poſſible,
the Plaiſtering tight and by no means ſubject
to crack. The Mouth of the Sluice muſt be
ſtopt with a Flood-gate, with which you may
ſhut out the Water when it happens to be tur
bid, and by means whereof you may have an
Opportunity to mend any Part of the Aque
duct which is decayed, without being prevent
ed by the Water; and this Flood-gate muſt
have a Grate of Braſs to it, that Water may
flow into the Aqueduct clearer and more re
fined, leaving behind it the Leaves, Boughs
and other Traſh that fall into it. At every
hundred Cubits muſt be either a Conduit-head,
or a Mill-dam twenty Foot broad, thirty long,
and fifteen deep below the Bottom of the Chan
nel; and theſe are made to the Intent that
thoſe Waters which either fall into the Aque
duct from the Earth, or are thrown into it too
violently, may have a Place to ſubſide below
the other Stream, which by that means will
have room to flow on more refined and clear.
The Mouth of the Aqueduct for diſcharging