1It is incredible the Violence and Impetuoſity
of Nature when the Wind in ſuch a Pipe is re
ſtrained and compreſſed too cloſe. I have read
in the Works of the Phyſicians, that the Bone of
a Man's Leg has been broken by the ſudden
Irruption of a Vapour ſo confined. The Ar
tiſts in Hydraulics can force Water to leap up
out of a Veſſel, by confining a Quantity of Air
between two Waters.
of Nature when the Wind in ſuch a Pipe is re
ſtrained and compreſſed too cloſe. I have read
in the Works of the Phyſicians, that the Bone of
a Man's Leg has been broken by the ſudden
Irruption of a Vapour ſo confined. The Ar
tiſts in Hydraulics can force Water to leap up
out of a Veſſel, by confining a Quantity of Air
between two Waters.
CHAP. VIII.
Of Ciſterns, their Uſes and Conveniencies.
I now come to ſpeak of Ciſterns. A Ciſtern
is a large Veſſel for holding Water, not
unlike the Water-houſe or Conduit-head. Its
Bottom and Sides therefore muſt be perfectly
ſtrong and well compacted. There are two
Sorts, one for containing Water for Drinking,
and the other for preſerving it for other Uſes,
as particularly againſt ſudden Fires. The firſt
we ſhall call a Drinking-ciſtern, the other a
Reſervoir. The Drinking-ciſtern out to pre
ſerve its Water in the greateſt Purity; becauſe
when it is impure it is the Cauſe of a great many
Inconveniencies. In both we are to take care
that the Water is properly admitted, preſerved
and diſpenſed. Water is brought into the Ciſ
tern by Pipes from the River or Spring, and
ſometimes Rain-water from the Houſe-top or
from the Ground. I was extremely pleaſed
with the Invention of an Architect, who in a
large bare Rock on the Summit of a Hill cut
a round Baſon ten Foot deep, which received
all the Rain-water which ran into it from that
naked Rock. Then in the Plain under the
Hill he erected a Water-houſe, open on every
Side, and built of Brick and Mortar, thirty
Foot high, forty long and forty broad. Into
this Water-houſe he brought the Rain-water
from the upper Reſervoir by a ſubterraneous
Conduit of brick Pipe; that Reſervoir lying
much higher than the Top of the Water-houſe.
If you ſtrew the Bottom of your Ciſtern with
good round Pebbles, or large Gravel from the
River very well waſhed, or rather fill it with it
to a certain Height, ſuppoſe of three Foot, it
will make your Water clear, cool and pure;
and the Higher you make this Strewing, your
Water will be the more limpid. The Water
ſometimes runs out at the Joints and Cracks
of the Ciſtern if it is ill made; and ſometimes
the Water is ſpoiled by Filth. And indeed it
is no eaſy Matter to keep Water impriſoned,
unleſs the Reſervoir be ſtrongly built, and even
of good ſquare Stone. It is alſo particularly
neceſſary, that the Work ſhould be perfectly
dry before you let the Water into it, which
preſſing hard upon it with its Weight, and
Sweating through it by means of its Humidi
ty, if it can but make a ſmall Crack, will be
continually working its Way till it has opened
itſelf a large Paſſage. The Ancients guarded
againſt this Inconvenience, and eſpecially in
the Corners of their Reſervoirs, by ſeveral Coats
of ſtrong Plaiſtering, and ſometimes by Incruſ
tations of Marbles. But nothing better pre
vents this oozing out of the Water, than Chalk
cloſe rammed in between the Wall of the Ciſ
tern and the Side of the Trench in which it is
made. We order the Chalk which we uſe for
this Purpoſe to be thoroughly dried and beat
into Powder. Some think, that if you fill a
Glaſs Veſſel with Salt, and ſtop it up cloſe
with a Plaiſter of Mortar tempered with Oil,
that no Water may get in, and then hang it
down in the Middle of the Ciſtern, it will pre
vent the Water from corrupting, let it be kept
ever ſo long. Some add Quick-ſilver to the
Compoſition. Others ſay, that if you take a
new earthen Veſſel full of ſharp Vinegar, ſtopt
up as above, and ſet it in the Water, it will en
tirely clear it from all Slime. They tell us too,
that either a Ciftern or a Well are purified by
putting ſome ſmall Fiſh into them, thinking
that the Fiſh feed upon the Slime of the Wa
ter and of the Earth. We are told of an old
Saying of Epigenes, that Water which has been
once corrupted, will in Time recover and pu
rify itſelf, and after that never ſpoil any more.
Water which is beginning to corrupt, if it is
ſtirred about, and poured often out of one Veſ
ſel into another, will loſe its ill Smell, which
will alſo hold good of Wine and Oil that is
mothery. Joſephus relates, that when Moſes
came to a dry Place, where there was only one
Spring of Water, and that foul and bitter, he
commanded the Soldiers to draw it; and upon
their beating and ſtirring it about heartily, it
became drinkable. It is certain that Water
may be purified by boiling and ſtraining; and
is a large Veſſel for holding Water, not
unlike the Water-houſe or Conduit-head. Its
Bottom and Sides therefore muſt be perfectly
ſtrong and well compacted. There are two
Sorts, one for containing Water for Drinking,
and the other for preſerving it for other Uſes,
as particularly againſt ſudden Fires. The firſt
we ſhall call a Drinking-ciſtern, the other a
Reſervoir. The Drinking-ciſtern out to pre
ſerve its Water in the greateſt Purity; becauſe
when it is impure it is the Cauſe of a great many
Inconveniencies. In both we are to take care
that the Water is properly admitted, preſerved
and diſpenſed. Water is brought into the Ciſ
tern by Pipes from the River or Spring, and
ſometimes Rain-water from the Houſe-top or
from the Ground. I was extremely pleaſed
with the Invention of an Architect, who in a
large bare Rock on the Summit of a Hill cut
a round Baſon ten Foot deep, which received
all the Rain-water which ran into it from that
naked Rock. Then in the Plain under the
Hill he erected a Water-houſe, open on every
Side, and built of Brick and Mortar, thirty
Foot high, forty long and forty broad. Into
this Water-houſe he brought the Rain-water
from the upper Reſervoir by a ſubterraneous
Conduit of brick Pipe; that Reſervoir lying
much higher than the Top of the Water-houſe.
If you ſtrew the Bottom of your Ciſtern with
good round Pebbles, or large Gravel from the
River very well waſhed, or rather fill it with it
to a certain Height, ſuppoſe of three Foot, it
will make your Water clear, cool and pure;
and the Higher you make this Strewing, your
Water will be the more limpid. The Water
ſometimes runs out at the Joints and Cracks
of the Ciſtern if it is ill made; and ſometimes
the Water is ſpoiled by Filth. And indeed it
is no eaſy Matter to keep Water impriſoned,
unleſs the Reſervoir be ſtrongly built, and even
of good ſquare Stone. It is alſo particularly
neceſſary, that the Work ſhould be perfectly
dry before you let the Water into it, which
preſſing hard upon it with its Weight, and
Sweating through it by means of its Humidi
ty, if it can but make a ſmall Crack, will be
continually working its Way till it has opened
itſelf a large Paſſage. The Ancients guarded
againſt this Inconvenience, and eſpecially in
the Corners of their Reſervoirs, by ſeveral Coats
of ſtrong Plaiſtering, and ſometimes by Incruſ
tations of Marbles. But nothing better pre
vents this oozing out of the Water, than Chalk
cloſe rammed in between the Wall of the Ciſ
tern and the Side of the Trench in which it is
made. We order the Chalk which we uſe for
this Purpoſe to be thoroughly dried and beat
into Powder. Some think, that if you fill a
Glaſs Veſſel with Salt, and ſtop it up cloſe
with a Plaiſter of Mortar tempered with Oil,
that no Water may get in, and then hang it
down in the Middle of the Ciſtern, it will pre
vent the Water from corrupting, let it be kept
ever ſo long. Some add Quick-ſilver to the
Compoſition. Others ſay, that if you take a
new earthen Veſſel full of ſharp Vinegar, ſtopt
up as above, and ſet it in the Water, it will en
tirely clear it from all Slime. They tell us too,
that either a Ciftern or a Well are purified by
putting ſome ſmall Fiſh into them, thinking
that the Fiſh feed upon the Slime of the Wa
ter and of the Earth. We are told of an old
Saying of Epigenes, that Water which has been
once corrupted, will in Time recover and pu
rify itſelf, and after that never ſpoil any more.
Water which is beginning to corrupt, if it is
ſtirred about, and poured often out of one Veſ
ſel into another, will loſe its ill Smell, which
will alſo hold good of Wine and Oil that is
mothery. Joſephus relates, that when Moſes
came to a dry Place, where there was only one
Spring of Water, and that foul and bitter, he
commanded the Soldiers to draw it; and upon
their beating and ſtirring it about heartily, it
became drinkable. It is certain that Water
may be purified by boiling and ſtraining; and
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