1Pay, only to preſerve and look after the pub
lick Buildings. Agrippa left Pay for two hun
dred and fifty for this Purpoſe, and Cæſar for
no leſs than four hundred and ſixty; and they
dedicated the next fifteen Feet to the Structure
to lie quite clear by their Aqueducts, that their
Sides or Arches might not breed any Weeds
to demoliſh them. The ſame ſeems to have
been done even by private Perſons, with re
lation to thoſe Edifices which they were de
ſirous to have eternal; for we find, that the
Inſcription upon their Sepulchres generally
mentioned how many Foot of Ground was
conſecrated to Religion in that Structure;
ſometimes it was fifteen, ſometimes twenty.
But not to fall into a Repetition of theſe Things,
the Ancients thought, that you might entirely
deſtroy a Tree even after it was pretty well
grown, if in ſome Part of the Dog-days you
cut it down to the Height of one Foot, and
boring a Hole through the Heart, pour into it
Oil of Vitriol mixed with Powder of Brimſtone,
or elſe ſprinkling it plentifully with a Decoc
tion of burnt Bean-ſhells. Columella ſays, that
you may deſtroy a Wood with the Flower of
Hops ſteept one Day in Juice of Hemlock,
ſtrewed about the Roots. Solinus ſays, that a
Tree touched with the Menſtrua will loſe its
Leaves, and ſome affirm, that it will even kill
the Tree. Pliny ſays, that a Tree may be
killed by touching the Root with a wild Car
rot. But to return to the Defects of a Wall.
If a Wall be thinner than it ought to be, we
muſt either apply a new Wall to the old one,
in ſuch a Manner that they may make but
one; or, to avoid the Expence of this, we
may only ſtrengthen it with Ribs, that is to
ſay, with Pilaſters or Columns. A new Wall
may be ſuperinduced to an old one, as follows.
In ſeveral Parts of the old Wall fix ſtrong
Catches made of the ſoundeſt Stone, ſticking
out in ſuch a Manner as to enter into the Wall
which you are going to join to the other, and
to be in the Nature of Bands between the two
Walls; and your Wall in this Caſe ſhould al
ways be built of ſquare Stone. You may for
tify an old Wall with a new Pilaſter, in the
following Manner. Firſt mark out its future
Breadth upon the Wall with red Oker. Then
open a Break in the Bottom of the Wall quite
down below the Foundation, in Breadth ſome
ſmall Matter more than your Pilaſter, but not
very high. Then immediately fill up this Break
with ſquare Stone worked together ſtrong and
even. By this Means that Part of the Wall
which is between the red Marks will be ſhored
up by the Thickneſs of the Pilaſter, and ſo the
whole will be made ſtronger. Then in the
ſame Manner that you have laid the Bottom of
this Pilaſter you muſt go on to work up the
Body of it quite to the Top. Thus much of
a Wall that is too thin. Where the Wall has
not made good Bond, we muſt uſe Cramps or
Spars of Iron, or rather of Braſs; but you
muſt take great Care that you do not weaken
the Ribs by boring the Holes from them. If
the Weight of any crumbling Earth puſhes
againſt ſome Part of the Wall, and threatens
Injury to it by its Humidity, dig a Trench
along the Wall as broad as you find it neceſ
ſary, and in this Trench build ſome Arches to
ſupport the Weight of the Earth which is
falling in, with a Current or Drain through
theſe Arches for the Humidity to purge off
by; ot elſe lay ſome Girders along the Ground
with the Heads ſetting againſt the Wall which
is ſhoved out by the Weight of the Earth, and
let the Heads of theſe Girders into Summers,
which you may cover over with new Earth.
This will ſtrengthen the Foundation, becauſe
this new Earth will conſolidate, and grow
compact, before the Strength of the Girders
will give Way.
lick Buildings. Agrippa left Pay for two hun
dred and fifty for this Purpoſe, and Cæſar for
no leſs than four hundred and ſixty; and they
dedicated the next fifteen Feet to the Structure
to lie quite clear by their Aqueducts, that their
Sides or Arches might not breed any Weeds
to demoliſh them. The ſame ſeems to have
been done even by private Perſons, with re
lation to thoſe Edifices which they were de
ſirous to have eternal; for we find, that the
Inſcription upon their Sepulchres generally
mentioned how many Foot of Ground was
conſecrated to Religion in that Structure;
ſometimes it was fifteen, ſometimes twenty.
But not to fall into a Repetition of theſe Things,
the Ancients thought, that you might entirely
deſtroy a Tree even after it was pretty well
grown, if in ſome Part of the Dog-days you
cut it down to the Height of one Foot, and
boring a Hole through the Heart, pour into it
Oil of Vitriol mixed with Powder of Brimſtone,
or elſe ſprinkling it plentifully with a Decoc
tion of burnt Bean-ſhells. Columella ſays, that
you may deſtroy a Wood with the Flower of
Hops ſteept one Day in Juice of Hemlock,
ſtrewed about the Roots. Solinus ſays, that a
Tree touched with the Menſtrua will loſe its
Leaves, and ſome affirm, that it will even kill
the Tree. Pliny ſays, that a Tree may be
killed by touching the Root with a wild Car
rot. But to return to the Defects of a Wall.
If a Wall be thinner than it ought to be, we
muſt either apply a new Wall to the old one,
in ſuch a Manner that they may make but
one; or, to avoid the Expence of this, we
may only ſtrengthen it with Ribs, that is to
ſay, with Pilaſters or Columns. A new Wall
may be ſuperinduced to an old one, as follows.
In ſeveral Parts of the old Wall fix ſtrong
Catches made of the ſoundeſt Stone, ſticking
out in ſuch a Manner as to enter into the Wall
which you are going to join to the other, and
to be in the Nature of Bands between the two
Walls; and your Wall in this Caſe ſhould al
ways be built of ſquare Stone. You may for
tify an old Wall with a new Pilaſter, in the
following Manner. Firſt mark out its future
Breadth upon the Wall with red Oker. Then
open a Break in the Bottom of the Wall quite
down below the Foundation, in Breadth ſome
ſmall Matter more than your Pilaſter, but not
very high. Then immediately fill up this Break
with ſquare Stone worked together ſtrong and
even. By this Means that Part of the Wall
which is between the red Marks will be ſhored
up by the Thickneſs of the Pilaſter, and ſo the
whole will be made ſtronger. Then in the
ſame Manner that you have laid the Bottom of
this Pilaſter you muſt go on to work up the
Body of it quite to the Top. Thus much of
a Wall that is too thin. Where the Wall has
not made good Bond, we muſt uſe Cramps or
Spars of Iron, or rather of Braſs; but you
muſt take great Care that you do not weaken
the Ribs by boring the Holes from them. If
the Weight of any crumbling Earth puſhes
againſt ſome Part of the Wall, and threatens
Injury to it by its Humidity, dig a Trench
along the Wall as broad as you find it neceſ
ſary, and in this Trench build ſome Arches to
ſupport the Weight of the Earth which is
falling in, with a Current or Drain through
theſe Arches for the Humidity to purge off
by; ot elſe lay ſome Girders along the Ground
with the Heads ſetting againſt the Wall which
is ſhoved out by the Weight of the Earth, and
let the Heads of theſe Girders into Summers,
which you may cover over with new Earth.
This will ſtrengthen the Foundation, becauſe
this new Earth will conſolidate, and grow
compact, before the Strength of the Girders
will give Way.
CHAP. XVII.
Of ſome Defects which cannot be provided againſt, but which may be repaired
after they have happened.
after they have happened.
I now proceed to thoſe Defects which can
not be foreſeen, but which when they have
happened may be repaired. Cracks in the
Wall and Inclination from the Perpendicular,
are ſometimes occaſioned by the Arches over it,
which puſh out the Wall, or becauſe it is not
ſufficiently ſtrong to bear the Weight which is
laid upon it. But the greateſt Defects of this
Sort almoſt conſtantly proceed from ſome Faults
in the Foundation; however we may eaſily
not be foreſeen, but which when they have
happened may be repaired. Cracks in the
Wall and Inclination from the Perpendicular,
are ſometimes occaſioned by the Arches over it,
which puſh out the Wall, or becauſe it is not
ſufficiently ſtrong to bear the Weight which is
laid upon it. But the greateſt Defects of this
Sort almoſt conſtantly proceed from ſome Faults
in the Foundation; however we may eaſily
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