1with a Shade, is colder and clearer, but more
undigeſted, than thoſe warmed by the Sun;
and, on the contrary, Waters too much heated
by the Sun, are brackiſh and viſcous. The
being deep is of Service to either Sort, becauſe
it prevents the latter from being made too hot,
and the former from being too eaſily affected
by Froſt. Laſtly it is thought that even the
Marſh is not always to be deſpiſed: becauſe
where-ever Eels are found, the Water is reckoned
to be not very bad. Of all Marſh-water that
is accounted the very worſt which breeds Horſe
leeches, which is ſo abſolutely without Moti
on that it contracts a Scurf on the Top, which
has an offenſive Smell, which is of a black or
livid Colour, which being put into a Veſſel will
continue ſoul a great while, which is heavy and
clammy with a moſſy Slime, and which being
uſed in waſhing your Hands, they are a long
Time before they dry. But as a ſhort Summary
of what has been ſaid of Water, it ſhould be ex
tremely light, clear, thin and tranſparent, to
which muſt be added thoſe Particulars which
we have ſlightly touched in the firſt Book.
Laſtly it will be a ſtrong Confirmation to you
of the Goodneſs of your Water, if you find that
the Cattle which have waſhed and drank in it
for ſeveral Months together, are in good Con
dition and perfectly healthy; and you have a
ſure Way to judge whether they are ſound or
not by inſpecting their Livers; for what is
noxious injures with Time, and the Injury
which is lateſt felt is of the worſt Conſequence.
undigeſted, than thoſe warmed by the Sun;
and, on the contrary, Waters too much heated
by the Sun, are brackiſh and viſcous. The
being deep is of Service to either Sort, becauſe
it prevents the latter from being made too hot,
and the former from being too eaſily affected
by Froſt. Laſtly it is thought that even the
Marſh is not always to be deſpiſed: becauſe
where-ever Eels are found, the Water is reckoned
to be not very bad. Of all Marſh-water that
is accounted the very worſt which breeds Horſe
leeches, which is ſo abſolutely without Moti
on that it contracts a Scurf on the Top, which
has an offenſive Smell, which is of a black or
livid Colour, which being put into a Veſſel will
continue ſoul a great while, which is heavy and
clammy with a moſſy Slime, and which being
uſed in waſhing your Hands, they are a long
Time before they dry. But as a ſhort Summary
of what has been ſaid of Water, it ſhould be ex
tremely light, clear, thin and tranſparent, to
which muſt be added thoſe Particulars which
we have ſlightly touched in the firſt Book.
Laſtly it will be a ſtrong Confirmation to you
of the Goodneſs of your Water, if you find that
the Cattle which have waſhed and drank in it
for ſeveral Months together, are in good Con
dition and perfectly healthy; and you have a
ſure Way to judge whether they are ſound or
not by inſpecting their Livers; for what is
noxious injures with Time, and the Injury
which is lateſt felt is of the worſt Conſequence.
CHAP. VII.
Of the Method of conveying Water and accommodating it to the Uſes of Men.
Having found Water and approved
it to be good, the next Work is to convey
it artfully and accommodate it properly to the
Uſes of Men. There are two Ways of convey
ing Water, either by a Trench or Canal, or by
Pipes or Conduits. In either of theſe Methods,
the Water will not move, unleſs the Place to
which you would convey it be lower than that
from which it is to be brought. But then there
is this Difference, that the Water which is brought
by a Canal muſt deſcend all the Way with a
continued Slope, whereas that which is conveyed
in Pipes may aſcend in ſome Part of the Way.
Of theſe two Methods we are now to treat.
But firſt we muſt premiſe ſome Things for the
clearer Explication of our Subject. The
Searchers into Nature tell us, that the Earth is
Spherical, tho' in many Places it riſes into
Hills, and in many others ſinks into Seas: but
in ſo vaſt a Globe this Roughneſs is not per
ceptible; as in an Egg, which tho' it is far
from being of a ſmooth Superficies, yet its lit
tle Inequalities bearing but an inconſiderable
Proportion to its whole Circumference, they
are ſcarce obſerved. Eratoſthenes tells us, that
the Compaſs of this great Globe is two hun
dred and fifty two thouſand Furlongs, or about
thirty one thouſand five hundred Miles, and
that there is no Hill ſo high or Water ſo deep
as to be above fifteen thouſand Cubits perpen
dicular; not even Mount Caucaſus, whoſe Top
enjoys the Sun three Hours in the Night.
There is a prodigious high Mountain in Ar
cadia called Cyllene; and yet thoſe who have
meaſured its perpendicular, affirm, that it does
not exceed twenty Furlongs. Even the Sea it
ſelf is thought to be no more upon this Globe
of Earth, than the Summer's Dew is upon the
Body of an Apple. Some have wittily ſaid,
that the Creator of the World made uſe of the
Concavity of the Sea as of a Seal with the Im
preſſion whereof he ſtampt the Hills. What
the Geometers teach us upon this Head is very
much to our preſent Purpoſe. They ſay, that
if a ſtraight Line touching the Globe of the
Earth at one End were to be drawn on exactly
horizontal a Mile in Length, the Space be
tween the other End and the Surface of the
Globe would not be above ten Inches. For
this Reaſon Water will never move on in a
Canal, but ſtand ſtill like a Lake, unleſs every
eight Furlongs the Trench has a Slope of one
whole Foot from the Place where the Water
was firſt found and its Bed cut; which Place
the ancient Lawyers called Incile, from the In
ciſion which is made either in the Rock or
Bank for conveying the Water: But if in this
Space of eight Furlongs it had a Slope of more
than ſix Foot, it is ſuppoſed that the Rapidity
of its Current would make it inconvenient for
Boats. In order to find whether the Trench
which is to convey the Water be lower than
it to be good, the next Work is to convey
it artfully and accommodate it properly to the
Uſes of Men. There are two Ways of convey
ing Water, either by a Trench or Canal, or by
Pipes or Conduits. In either of theſe Methods,
the Water will not move, unleſs the Place to
which you would convey it be lower than that
from which it is to be brought. But then there
is this Difference, that the Water which is brought
by a Canal muſt deſcend all the Way with a
continued Slope, whereas that which is conveyed
in Pipes may aſcend in ſome Part of the Way.
Of theſe two Methods we are now to treat.
But firſt we muſt premiſe ſome Things for the
clearer Explication of our Subject. The
Searchers into Nature tell us, that the Earth is
Spherical, tho' in many Places it riſes into
Hills, and in many others ſinks into Seas: but
in ſo vaſt a Globe this Roughneſs is not per
ceptible; as in an Egg, which tho' it is far
from being of a ſmooth Superficies, yet its lit
tle Inequalities bearing but an inconſiderable
Proportion to its whole Circumference, they
are ſcarce obſerved. Eratoſthenes tells us, that
the Compaſs of this great Globe is two hun
dred and fifty two thouſand Furlongs, or about
thirty one thouſand five hundred Miles, and
that there is no Hill ſo high or Water ſo deep
as to be above fifteen thouſand Cubits perpen
dicular; not even Mount Caucaſus, whoſe Top
enjoys the Sun three Hours in the Night.
There is a prodigious high Mountain in Ar
cadia called Cyllene; and yet thoſe who have
meaſured its perpendicular, affirm, that it does
not exceed twenty Furlongs. Even the Sea it
ſelf is thought to be no more upon this Globe
of Earth, than the Summer's Dew is upon the
Body of an Apple. Some have wittily ſaid,
that the Creator of the World made uſe of the
Concavity of the Sea as of a Seal with the Im
preſſion whereof he ſtampt the Hills. What
the Geometers teach us upon this Head is very
much to our preſent Purpoſe. They ſay, that
if a ſtraight Line touching the Globe of the
Earth at one End were to be drawn on exactly
horizontal a Mile in Length, the Space be
tween the other End and the Surface of the
Globe would not be above ten Inches. For
this Reaſon Water will never move on in a
Canal, but ſtand ſtill like a Lake, unleſs every
eight Furlongs the Trench has a Slope of one
whole Foot from the Place where the Water
was firſt found and its Bed cut; which Place
the ancient Lawyers called Incile, from the In
ciſion which is made either in the Rock or
Bank for conveying the Water: But if in this
Space of eight Furlongs it had a Slope of more
than ſix Foot, it is ſuppoſed that the Rapidity
of its Current would make it inconvenient for
Boats. In order to find whether the Trench
which is to convey the Water be lower than
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