1Country, ſo the Platform is a certain determi
nate Part of the Region taken up by the
Building; and for this Reaſon, any Thing that
may annoy or be of Service to the Region,
may do the ſame to the Platform. But though
this be ſo, yet our Diſcuſſion and Conſiderati
ons here will offer us ſome Precepts, which
ſeem particularly to regard the Platform only;
and ſome again which do not ſeem ſo proper
ly to belong to the Seat as in a great Meaſure
to the Region; which are theſe. It is neceſ
ſary to conſider what Work we are taking in
Hand, publick or private, ſacred or profane,
and ſo of the Reſt, which we ſhall treat of diſ
tinctly in their proper Places. For one Situa
tion and one Space is to be allotted to an Ex
change, another to a Theatre, another to a
Palæſtra, or Place of Exerciſe, and another to
a Temple; ſo that we muſt have regard to the
Quality and Uſe of every Edifice in the Deter
mining of its Situation and Form. But to
proceed here only in a general Diſcuſſion of
theſe Things as we began, we ſhall touch on
ly upon thoſe Points which we judge neceſ
ſary: Firſt ſaying ſomething of Lines, which
may be of Service for underſtanding what fol
lows. For being to treat of the Deſign of the
Platform, it will not be inconvenient to explain
thoſe Things firſt whereof that Deſign con
ſiſts. Every Deſign therefore is compoſed of
Lines and Angles; the Lines are that extreme
Deſign which includes the whole Space of the
Platform. That Part of the Superficies of this
Deſign, which is contained between two Lines
touching at ſome certain Point, is called an
Angle. The Interſection therefore or croſſing
of two Lines over each other form four Angles.
If each of theſe Angles be equal to all and each
of the other three, they are called right Angles;
if they are leſs, they are called acute, and the
greater obtuſe. Of Lines too ſome are ſtrait
and others curve; of involved winding Lines
it is not neceſſary to ſpeak here. The ſtrait
Line is a Line drawn from one Point to an
other, the ſhorteſt Way that poſſibly can be.
The curve Line is Part of a Circle; a Circle
is a Draught made from one of two Points,
and turned upon the ſame Superficies in ſuch a
Manner, that in its whole Circumference it is
never nearer nor farther from that immoveable
Point the Centre, than it was at the firſt Turn.
But to this it is neceſſary to add, that the curve
Line, which was ſaid to be Part of the Circle,
among us Architects, for its Similitude, is call
ed an Arch. And the ſtrait Line, which is
drawn from the two extreme Points of the
curve Line, for the ſame Reaſon is called
a Chord. And that Line, which goes from
the middle Point of the Chord up to the
Arch, leaving equal Angles on each Side, is
called the Sagitta. And that which is carried
from the fixed immoveable Point within the
Circle to the curve Line of the Circle, is call
ed the Radius. And that immoveable Point
in the Middle is called the Centre. And the
Line which paſſes through the Centre and
touches both Sides of the Circumference, is
nate Part of the Region taken up by the
Building; and for this Reaſon, any Thing that
may annoy or be of Service to the Region,
may do the ſame to the Platform. But though
this be ſo, yet our Diſcuſſion and Conſiderati
ons here will offer us ſome Precepts, which
ſeem particularly to regard the Platform only;
and ſome again which do not ſeem ſo proper
ly to belong to the Seat as in a great Meaſure
to the Region; which are theſe. It is neceſ
ſary to conſider what Work we are taking in
Hand, publick or private, ſacred or profane,
and ſo of the Reſt, which we ſhall treat of diſ
tinctly in their proper Places. For one Situa
tion and one Space is to be allotted to an Ex
change, another to a Theatre, another to a
Palæſtra, or Place of Exerciſe, and another to
a Temple; ſo that we muſt have regard to the
Quality and Uſe of every Edifice in the Deter
mining of its Situation and Form. But to
proceed here only in a general Diſcuſſion of
theſe Things as we began, we ſhall touch on
ly upon thoſe Points which we judge neceſ
ſary: Firſt ſaying ſomething of Lines, which
may be of Service for underſtanding what fol
lows. For being to treat of the Deſign of the
Platform, it will not be inconvenient to explain
thoſe Things firſt whereof that Deſign con
ſiſts. Every Deſign therefore is compoſed of
Lines and Angles; the Lines are that extreme
Deſign which includes the whole Space of the
Platform. That Part of the Superficies of this
Deſign, which is contained between two Lines
touching at ſome certain Point, is called an
Angle. The Interſection therefore or croſſing
of two Lines over each other form four Angles.
If each of theſe Angles be equal to all and each
of the other three, they are called right Angles;
if they are leſs, they are called acute, and the
greater obtuſe. Of Lines too ſome are ſtrait
and others curve; of involved winding Lines
it is not neceſſary to ſpeak here. The ſtrait
Line is a Line drawn from one Point to an
other, the ſhorteſt Way that poſſibly can be.
The curve Line is Part of a Circle; a Circle
is a Draught made from one of two Points,
and turned upon the ſame Superficies in ſuch a
Manner, that in its whole Circumference it is
never nearer nor farther from that immoveable
Point the Centre, than it was at the firſt Turn.
But to this it is neceſſary to add, that the curve
Line, which was ſaid to be Part of the Circle,
among us Architects, for its Similitude, is call
ed an Arch. And the ſtrait Line, which is
drawn from the two extreme Points of the
curve Line, for the ſame Reaſon is called
a Chord. And that Line, which goes from
the middle Point of the Chord up to the
Arch, leaving equal Angles on each Side, is
called the Sagitta. And that which is carried
from the fixed immoveable Point within the
Circle to the curve Line of the Circle, is call
ed the Radius. And that immoveable Point
in the Middle is called the Centre. And the
Line which paſſes through the Centre and
touches both Sides of the Circumference, is
called the Diameter. Arches too are different,
for ſome are entire, ſome are imperfect, and
ſome are compoſite. The entire is that which
is the full Half of a Circle, or that whoſe
Chord is the Diameter of the whole Circle.
The Imperfect is that whoſe Chord is leſs than
a Diameter, ſo that this imperfect Arch is Part
of a Semi-circle. The compoſite Arch is
formed of two imperfect Arches, and ſo the
joyning of thoſe two Arches, interſecting each
other, makes an Angle at Top, which never
happens either in the entire or imperfect Arch.
Theſe Things being premiſed, we proceed as
follows.
*
CHAP. VIII.
Of Platforms, ſome are angular and others
circular; of the angular, ſome conſiſt
all of right Lines, and ſome of right Lines
and curve mixed together. But I do not re
member among the Buildings of the Ancients
to have met with any angular Deſign, com
poſed of ſeveral curve Lines, without any Mix
ture of ſtrait Lines at all: But in this we
ſhould have regard to thoſe Things, which be
ing wanting in all Parts of the Structure, are
greatly blamed; and which, where they are,
make the Edifice handſome and convenient.
circular; of the angular, ſome conſiſt
all of right Lines, and ſome of right Lines
and curve mixed together. But I do not re
member among the Buildings of the Ancients
to have met with any angular Deſign, com
poſed of ſeveral curve Lines, without any Mix
ture of ſtrait Lines at all: But in this we
ſhould have regard to thoſe Things, which be
ing wanting in all Parts of the Structure, are
greatly blamed; and which, where they are,
make the Edifice handſome and convenient.