1diſcover whether they are from thence, or from
ſome other Cauſe by certain Symptoms. Thus
to begin with Cracks in the Wall; to which ſo
ever Side the Crack runs in its Aſcent, on that
Side you may be ſure the Cauſe of the Defect
lies ſomewhere in the Foundation. If it does
not verge to either Side, but runs up in a direct
Line, and grows wider at the Top, then let us
take a careful View of the Courſes of Stone
work on each Side; for on which ever Side
they ſink from their Level, on that Side we
may be ſure the Foundation has failed. But
if the upper Part of the Wall is entire, and
there are Cracks in ſeveral Places towards the
Bottom, which in their Aſcent run together
cloſe at Top; then we may be ſatisfied that
the Corners of the Building ſtand firm, and
that the Defect is ſomewhere about the Mid
dle in the Foundation. If there is but one
Crack of this Sort, the higher up it goes, the
the more it ſhews the Corners to have given
Way. In order to ſtrengthen the Foundations
in any of theſe Caſes, according to the Magni
tude of the Structure and the Solidity of the
Ground, dig a narrow Pit near the Wall, but
ſo deep as to come to a firm Soil, and there
breaking through the Bottom of the Wall,
immediately work up to it with ſquare Stone,
and then leave it to ſettle. When that is ſet
tled, dig another Pit in another Part, and un
derprop it in the ſame Manner, and in the ſame
Manner give it Time to ſettle. By this Means
you will make a Kind of new Foundation to
the whole Wall. But if even by digging you
cannot come at any firm Ground, then make
Holes in certain Places not too near the Cor
ners, but pretty cloſe to the Foundation of the
Wall, on both Sides, that is to ſay, as well un
der the Roof as under the open Air, and into
thoſe Holes drive Piles as cloſe as they will ſtick,
and over them lay the ſtouteſt Summers you
can get lengthways, with the Sides of the Wall.
Then acroſs theſe Summers lay the ſtrongeſt
Girders running under the Bottom of the
Foundation, which muſt reſt with their whole
Weight upon theſe Girders, as it were upon a
Bridge. In all theſe Reparations great Care
muſt be taken that no Part of the new Work
be too weak to ſupport the Weight which is to
bear upon it, and that for ever ſo long
Time: becauſe the whole Pile bearing towards
that weaker Part, would immediately fall to
Ruins. But where the Foundation has given
Way ſomewhere about the Middle of the Wall,
and the upper Part does not appear to be af
fected by the Crack, then upon the Face of
the Wall mark out with your Oker an Arch
as large as the Caſe requires, or, in other Words,
ſo big as to take in all that Part of the Wall
which is ſunk. Then beginning at one End
of this Arch, break into the Wall with an
Opening not bigger than one Stone of your in
tended Arch will fill up; which Stones in an
Arch we formerly called Wedges, and im
mediately inſert one of theſe Wedges in ſuch a
Manner that its Lines may exactly anſwer to
the Center to which you have deſcribed your
Arch. Then make another Break cloſe above
it, and fill it up with another ſuch Wedge;
and ſo continuing the Work ſucceſſively,
compleat your whole Arch: and thus you
may fortify you Wall without Danger. If a
Column or any other of the Ribs of the Building
is weakened, you may reſtore it in the following
Manner. Underprop the Architrave with a
ſtrong Arch of Tile and Plaiſter beat together,
as alſo with Piers of Plaiſter rais'd for this
Purpoſe, in ſuch a Manner that this new Arch
may quite fill up the old Intercolumnation, or
Aperture between the Ribs: and let this un
derproping be run up as faſt as poſſible, and
without the leaſt Intermiſſion. It is the Nature
of Plaiſter to ſwell as it dries: ſo that this new
Work, though quite freſh, will be able to take
upon itſelf and ſuſtain the Weight of the old
Wall Vault. Then, having before got ready
all your Materials, take out the defective
Column, and ſupply its Place with a ſound
one. If you chuſe rather to reſt the old Wall
upon Timbers, then underſhore it with Levers
made of ſtrong Beams, and load the longer
Ends of thoſe Levers with Baskets filled with
Sand, which will raiſe up the Weight by de
grees equally and without any Shocks. If the
Wall is ſwerved from its Perpendicular, fix
Planks or Timbers upright againſt it, and
againſt each of theſe ſet a ſtrong Timber by
Way of Shore, with its Foot ſtretching at ſome
Diſtance from the Wall. Then either with
Levers or with Wedges, drive forwards the Feet
of the Shores by degrees, ſo as they may preſs
againſt the Wall, and ſo by diſtributing this
Force equally in all Parts, you will raiſe the
Wall again to its perpendicular. If this
cannot be done, prop it up with Shores of
Timber fixed well in the Ground, with their
Ends well daubed over with Pitch and Oil to
prevent their being corroded by the Touch of
Mortar; then erect Buttreſſes of ſquare Stone,
built ſo as to encloſe thoſe Shores of Timber.
ſome other Cauſe by certain Symptoms. Thus
to begin with Cracks in the Wall; to which ſo
ever Side the Crack runs in its Aſcent, on that
Side you may be ſure the Cauſe of the Defect
lies ſomewhere in the Foundation. If it does
not verge to either Side, but runs up in a direct
Line, and grows wider at the Top, then let us
take a careful View of the Courſes of Stone
work on each Side; for on which ever Side
they ſink from their Level, on that Side we
may be ſure the Foundation has failed. But
if the upper Part of the Wall is entire, and
there are Cracks in ſeveral Places towards the
Bottom, which in their Aſcent run together
cloſe at Top; then we may be ſatisfied that
the Corners of the Building ſtand firm, and
that the Defect is ſomewhere about the Mid
dle in the Foundation. If there is but one
Crack of this Sort, the higher up it goes, the
the more it ſhews the Corners to have given
Way. In order to ſtrengthen the Foundations
in any of theſe Caſes, according to the Magni
tude of the Structure and the Solidity of the
Ground, dig a narrow Pit near the Wall, but
ſo deep as to come to a firm Soil, and there
breaking through the Bottom of the Wall,
immediately work up to it with ſquare Stone,
and then leave it to ſettle. When that is ſet
tled, dig another Pit in another Part, and un
derprop it in the ſame Manner, and in the ſame
Manner give it Time to ſettle. By this Means
you will make a Kind of new Foundation to
the whole Wall. But if even by digging you
cannot come at any firm Ground, then make
Holes in certain Places not too near the Cor
ners, but pretty cloſe to the Foundation of the
Wall, on both Sides, that is to ſay, as well un
der the Roof as under the open Air, and into
thoſe Holes drive Piles as cloſe as they will ſtick,
and over them lay the ſtouteſt Summers you
can get lengthways, with the Sides of the Wall.
Then acroſs theſe Summers lay the ſtrongeſt
Girders running under the Bottom of the
Foundation, which muſt reſt with their whole
Weight upon theſe Girders, as it were upon a
Bridge. In all theſe Reparations great Care
muſt be taken that no Part of the new Work
be too weak to ſupport the Weight which is to
bear upon it, and that for ever ſo long
Time: becauſe the whole Pile bearing towards
that weaker Part, would immediately fall to
Ruins. But where the Foundation has given
Way ſomewhere about the Middle of the Wall,
and the upper Part does not appear to be af
fected by the Crack, then upon the Face of
the Wall mark out with your Oker an Arch
as large as the Caſe requires, or, in other Words,
ſo big as to take in all that Part of the Wall
which is ſunk. Then beginning at one End
of this Arch, break into the Wall with an
Opening not bigger than one Stone of your in
tended Arch will fill up; which Stones in an
Arch we formerly called Wedges, and im
mediately inſert one of theſe Wedges in ſuch a
Manner that its Lines may exactly anſwer to
the Center to which you have deſcribed your
Arch. Then make another Break cloſe above
it, and fill it up with another ſuch Wedge;
and ſo continuing the Work ſucceſſively,
compleat your whole Arch: and thus you
may fortify you Wall without Danger. If a
Column or any other of the Ribs of the Building
is weakened, you may reſtore it in the following
Manner. Underprop the Architrave with a
ſtrong Arch of Tile and Plaiſter beat together,
as alſo with Piers of Plaiſter rais'd for this
Purpoſe, in ſuch a Manner that this new Arch
may quite fill up the old Intercolumnation, or
Aperture between the Ribs: and let this un
derproping be run up as faſt as poſſible, and
without the leaſt Intermiſſion. It is the Nature
of Plaiſter to ſwell as it dries: ſo that this new
Work, though quite freſh, will be able to take
upon itſelf and ſuſtain the Weight of the old
Wall Vault. Then, having before got ready
all your Materials, take out the defective
Column, and ſupply its Place with a ſound
one. If you chuſe rather to reſt the old Wall
upon Timbers, then underſhore it with Levers
made of ſtrong Beams, and load the longer
Ends of thoſe Levers with Baskets filled with
Sand, which will raiſe up the Weight by de
grees equally and without any Shocks. If the
Wall is ſwerved from its Perpendicular, fix
Planks or Timbers upright againſt it, and
againſt each of theſe ſet a ſtrong Timber by
Way of Shore, with its Foot ſtretching at ſome
Diſtance from the Wall. Then either with
Levers or with Wedges, drive forwards the Feet
of the Shores by degrees, ſo as they may preſs
againſt the Wall, and ſo by diſtributing this
Force equally in all Parts, you will raiſe the
Wall again to its perpendicular. If this
cannot be done, prop it up with Shores of
Timber fixed well in the Ground, with their
Ends well daubed over with Pitch and Oil to
prevent their being corroded by the Touch of
Mortar; then erect Buttreſſes of ſquare Stone,
built ſo as to encloſe thoſe Shores of Timber.