_Of the_ Ionick _Order_.
[Sidenote: _Lib. 4. Chap. 1._]
The Proportion of the Pillars of the _Ionick Order_ in the beginning had
Eight _Modules_ or Diameters for their height, but the Ancients quickly
added half a Diameter, when to make this Pillar more Beautiful than the
_Dorick_, not only for its height, but also for its Ornaments, they
added a _Base_ to it, which was not used in the _Dorick Order_.
The Pillars must be set upon their _Bases_ two ways; for sometimes they
were perpendicularly set, and sometimes not, _viz._ The outward rows of
Pillars; when there were more Ranks than one; for that part of the
Pillar which is towards the Wall of the Fabrick must necessarily be
perpendicular, and the outward part must have all the Diminution, and
must lean towards the Wall.
[Sidenote: _Lib. 3. Chap. 3._]
The Pillars that are within the porch, and are betwixt the Wall and the
outward Pillar must stand perpendicularly.
The breadth of the _Ionick Base_ is the Diameter of the Pillar, to which
is added a 4th. and an 8th. part; its height is half the Diameter; its
height being divided into three parts, one is allowed for the
_Plinthus_, the rest being divided into seven parts, three are allowed
to the _Torus_ above, after equally dividing the four which remain, the
two above are for the upper _Scotia_, with its _Astragal_: The two below
are for the lower _Scotia_, which will appear greater than the upper,
because it extends to the edge of the _Plinthus_, the _Astragals_ must
have the 8th. part of the _Scotia_, whose Jetting or Projecture must be
the 8th. part of the whole _Base_ joyned to the 6th. part of the
Diameter of the Pillar. See Tab. VII.
As to the _Capital_, the _Abacus_ must have in its Square the Diameter
of the bottom of the Pillar, adding to it an 18th. part; half of the
_Abacus_ ought to be the height of the _Capital_, comprizing the Round
of the _Volute_ or _Scroll_, but there must be substracted from the
corner of the _Abacus_ a 12th. part and an half of the height of the
_Capital_, and after the whole thickness of the _Capital_ must be
divided into nine parts and an half, and one and an half must be left
for the thickness of the _Abacus_, that the _Volutes_ or _Scrolls_ may
be made of the eight which remain; then having left under the _Abacus_
four parts and an half of these eight, a Line must be drawn in the place
which cuts the two a-cross and the Points of the Section shall be
_Eyes_, which shall have eight parts for their Diameter; in half the
space of the _Eye_ shall be placed the Centers through which shall be
drawn with a Compass the Spiral-Line of the _Volute_, beginning the
height under the _Abacus_, and going into the four Quarters of the
Division, diminishing till we come directly to the first Quarter, and
giving to every Quarter a particular Center.
Then the thickness of the whole _Capital_ must be so divided that of
nine parts which it contains, the _Volute_ has the breadth of three
under the _Astragal_, on the top of the Pillar, which must be directly
upon the _Eye_ of the _Volute_, that which remains above the _Astragal_,
must be allowed for the _Abacus_, _Channel_, and the _Echine_ or _Egge_,
whose jetting beyond the Square of the _Abacus_ must be of the same
bigness of the _Echine_ or _Egge_.
The _Channel_ must be hollowed the 12th. part of its breadth.
The _Girdle_ or _Cincture_, or the lateral part of the _Capital_, ought
to advance out of the _Tailhoir Abacus_, as much as it is from the
Center of the _Eye_ to the height of the _Echine_.
The thickness of the _Axis_ of the _Volutes_, which is the thickness of
the _Volute_, seen sideway, and which makes up the extreme parts of that
which is called commonly _Balisters_, ought not to exceed the magnitude
of the _Eye_. See Tab. VIII.
These Proportions of the _Ionick Capital_, are only for Pillars of 15
Foot, those that are greater require other, and generally the greater
Proportions are required for the Pillars that are greater; and for this
reason we have said, that the higher the Pillars are, the less
Diminution they must have; so when the Pillars are above 15 Foot, we
must add a 9th. part to the Diameter of the Pillar for to give the
breadth to the _Abacus_; to which is never added more than an 18th. part
to Pillars of 15 Foot.
The _Architraves_ shall be laid upon the Pillars with Jettings equal to
the _Pedestals_, in case they be not all of one size, but in form of
Joint-Stools, to the end Symmetry may be observ'd.
The height ought to be different, according to the proportion of the
height of the Pillar; for if the Pillar be from 12 to 15 Foot, we must
allow the _Architrave_ the height of half a Diameter of the bottom of
the Pillar, if it be from 15 to 20, we must divide the height of the
Pillar into 15 parts, to the end we may allow one to the _Architrave_;
so if it be from 20 to 25, the height must be divided into 12 parts and
an half, that the _Architrave_ may have one; and so proportionably.
The _Architrave_ ought to have at the bottom which lies upon the
_Capital_, the same breadth that the top of the Pillar hath under the
_Capital_.
The Jetting of the _Cymatium_ of the _Architrave_ ought to answer the
bottom of the Pillar, the height of the _Cymatium_ ought to be the 7th.
part of the whole _Architrave_.
The rest being divided into 12 parts; three must be allowed to the first
_Face_, four to the second, and five to that above, upon which is the
_Cymatium_.
The _Frise_ ought not to be so high as the _Architrave_ by a 4th. part,
unless something be carved there, for then that the Carving may be more
graceful, the _Frise_ ought to be bigger than the _Architrave_ by a 4th.
part.
Upon the _Frise_ must be made a _Cymatium_ of height the 7th. part of
the _Frise_, with a Jetting equal to its height.
The _Dentil_ which is upon the _Cymatium_, shall have the height of the
_Face_ of the middle of the _Architrave_, with a Jetting or Projecture
equal to its height; the cutting of the _Dentils_ ought to be so made,
that the breadth of every _Dentil_ may be the half of its height, and
the Cavity of the cut which is between every _Dentil_ may have two parts
of three, which maketh the breadth of the _Dentil_.
The _Cymatium_ which is upon the _Dentil_, must have the 3d. part of the
height of the _Dentil_.
The Crown with its little _Cymatium_ must have the same height with the
_Face_ of the middle of the _Architrave_.
The great _Cymatium_ ought to have the height of an 8th. part more than
the _Crown_ or _Drip_.
The Jetting or Projecture of the whole _Cornice_ comprehending the
_Dentil_ ought to be equal to the space that there is from the _Frise_,
just to the top of the great _Cymatium_, and generally speaking all the
Jettings or Projectures shall have the better grace when they are equal
to the height of the Jetting Members. See Table VII.