CHAP. IV.
But to return to the Walls. The Ancients
adviſe us to build them after this Man
ner. Raiſe two Walls one within the other,
leaving between them a Space of twenty Foot,
which Space is to be fill'd up with the Earth
dug out of the Ditch, and well ramm'd in;
and let theſe Walls be built in ſuch a Manner,
that you may mount from the Level of the
City quite to the Top of the Battlements, by
an eaſy Aſcent, as it were by Steps. Others
ſay, that the Earth which is dug out of the
Ditch, ought to be thrown without the Wall,
on the other Side of the Ditch, and there caſt
up into a Rampart, and from the Bottom of
the Ditch a Wall ſhould be run up, thick
and ſtrong enough to ſupport the Weight of the
aforeſaid Earth which bears upon it. At a
Diſtance from this another Wall ſhould be
raiſed in the Town, higher than the other, and
as far from it, as to leave Space enough for
the Soldiers to be drawn up, and to have
Room to fight in. Beſides this, you ſhould
between the principal Walls, and thoſe within,
erect other Walls croſſways from one to the
other, by the Help whereof, the principal
Walls may unite with thoſe behind, and more
eaſily ſupport the Weight of the Earth caſt in
between them. But indeed for my Part, I am
beſt pleaſed with thoſe Walls which are ſo
ſituated, that if they happen to be at length
demoliſhed by the Force of Battery, they have
ſomewhat of a Plain at the Foot of them,
where they may lie and form a Kind of Ram
part, and ſo be kept from filling up the Ditch
with their Ruins. In other Reſpects I am
very well pleaſed with Vitruvius, who ſays
the Wall ought to be built thus: Within the
Body of the Wall we ſhould lay a good many
Timbers of Olive-wood burnt, to the Intent
that the two Sides of the Walls being faſtened
together by theſe wooden Bracers, the Work
may be the more durable. Such a Wall as this,
we are told by Thucydides, was made by the
Platæans, to defend themſelves againſt the
People of the Morea, by whom they were be
ſieged; inaſmuch as they mixed Timbers a
mong their Brick-work, and made a very ſtout
Fortification of it. And Cæſar informs us,
that in France moſt of their Walls were built
in this Manner: They laid Beams within the
Wall, and braced them together at equal Di
ſtances, filling up the Vacancies with huge
Stones, ſo that one Beam never touched the
other; and ſo proceeded with ſeveral Courſes
of Work in the ſame Method, till they raiſed
a Wall of a good conſiderable Height. This
Kind of Work was not unhandſome to the
Sight, and was a very ſtrong Fortification, be
cauſe the Stones ſecured it againſt Fire, and
the Timbers againſt the Battering Rams. But
this mix'd Work others diſapprove of; becauſe
they ſay the Lime and the Wood will not
long agree together, for Timber is eaten and
burnt up both by the Saltneſs and Heat of the
Lime. Beſides that, if the Wall ſhould hap
pen to be demoliſh'd by Battery, they ſay,
that as it is thus made in a Manner all of one
Piece, the whole Wall will be apt to go all
together at once. In my Opinion one very
good Way of Building a ſtrong Wall, capable
to ſtand the Shocks of Engines, is this: make tri
angular Projections out from the naked of the
Wall, with one Angle facing the Enemy, at the
Diſtance of every ten Cubits, and turn Arches
from one Projection to the other; then fill up the
Vacancies between them with Straw and Earth,
well rammed down together. By this Means
the Force and Violence of the Shocks of the
Engines, will be deadened by the Softneſs of the
Earth, and the Wall will not be weakned by
the Battery, only here and there, and thoſe
ſmall Breaches, or rather Holes, that are made
in it, will preſently be ſtopt up again. In Sicily,
their Pumice-ſtones, which they have in great
Plenty, will do extreamly well for this Kind of
Work: But in other Places, for want of Pu
mice-ſtones and Earth, any ſoft Stone may
be made uſe of; nor is Terraſs amiſs for this
Purpoſe. Laſtly, if any Part of ſuch a Struc
ture ſtands expoſed to the moſt ſoutherly
Winds, or nocturnal Vapours, cloath and face
it with a Shell of Stone. And particularly it
will be of great Service to let the outer Bank
of the Ditch have a good Slope, and lie a
adviſe us to build them after this Man
ner. Raiſe two Walls one within the other,
leaving between them a Space of twenty Foot,
which Space is to be fill'd up with the Earth
dug out of the Ditch, and well ramm'd in;
and let theſe Walls be built in ſuch a Manner,
that you may mount from the Level of the
City quite to the Top of the Battlements, by
an eaſy Aſcent, as it were by Steps. Others
ſay, that the Earth which is dug out of the
Ditch, ought to be thrown without the Wall,
on the other Side of the Ditch, and there caſt
up into a Rampart, and from the Bottom of
the Ditch a Wall ſhould be run up, thick
and ſtrong enough to ſupport the Weight of the
aforeſaid Earth which bears upon it. At a
Diſtance from this another Wall ſhould be
raiſed in the Town, higher than the other, and
as far from it, as to leave Space enough for
the Soldiers to be drawn up, and to have
Room to fight in. Beſides this, you ſhould
between the principal Walls, and thoſe within,
erect other Walls croſſways from one to the
other, by the Help whereof, the principal
Walls may unite with thoſe behind, and more
eaſily ſupport the Weight of the Earth caſt in
between them. But indeed for my Part, I am
beſt pleaſed with thoſe Walls which are ſo
ſituated, that if they happen to be at length
demoliſhed by the Force of Battery, they have
ſomewhat of a Plain at the Foot of them,
where they may lie and form a Kind of Ram
part, and ſo be kept from filling up the Ditch
with their Ruins. In other Reſpects I am
very well pleaſed with Vitruvius, who ſays
the Wall ought to be built thus: Within the
Body of the Wall we ſhould lay a good many
Timbers of Olive-wood burnt, to the Intent
that the two Sides of the Walls being faſtened
together by theſe wooden Bracers, the Work
may be the more durable. Such a Wall as this,
we are told by Thucydides, was made by the
Platæans, to defend themſelves againſt the
People of the Morea, by whom they were be
ſieged; inaſmuch as they mixed Timbers a
mong their Brick-work, and made a very ſtout
Fortification of it. And Cæſar informs us,
that in France moſt of their Walls were built
in this Manner: They laid Beams within the
Wall, and braced them together at equal Di
ſtances, filling up the Vacancies with huge
Stones, ſo that one Beam never touched the
other; and ſo proceeded with ſeveral Courſes
of Work in the ſame Method, till they raiſed
a Wall of a good conſiderable Height. This
Kind of Work was not unhandſome to the
Sight, and was a very ſtrong Fortification, be
cauſe the Stones ſecured it againſt Fire, and
the Timbers againſt the Battering Rams. But
this mix'd Work others diſapprove of; becauſe
they ſay the Lime and the Wood will not
long agree together, for Timber is eaten and
burnt up both by the Saltneſs and Heat of the
Lime. Beſides that, if the Wall ſhould hap
pen to be demoliſh'd by Battery, they ſay,
that as it is thus made in a Manner all of one
Piece, the whole Wall will be apt to go all
together at once. In my Opinion one very
good Way of Building a ſtrong Wall, capable
to ſtand the Shocks of Engines, is this: make tri
angular Projections out from the naked of the
Wall, with one Angle facing the Enemy, at the
Diſtance of every ten Cubits, and turn Arches
from one Projection to the other; then fill up the
Vacancies between them with Straw and Earth,
well rammed down together. By this Means
the Force and Violence of the Shocks of the
Engines, will be deadened by the Softneſs of the
Earth, and the Wall will not be weakned by
the Battery, only here and there, and thoſe
ſmall Breaches, or rather Holes, that are made
in it, will preſently be ſtopt up again. In Sicily,
their Pumice-ſtones, which they have in great
Plenty, will do extreamly well for this Kind of
Work: But in other Places, for want of Pu
mice-ſtones and Earth, any ſoft Stone may
be made uſe of; nor is Terraſs amiſs for this
Purpoſe. Laſtly, if any Part of ſuch a Struc
ture ſtands expoſed to the moſt ſoutherly
Winds, or nocturnal Vapours, cloath and face
it with a Shell of Stone. And particularly it
will be of great Service to let the outer Bank
of the Ditch have a good Slope, and lie a