_What are the Parts of Architecture._
There are Three Things which ought to meet in every Fabrick, _viz._
_Solidity_, _Convenience_ and _Beauty_, which Architecture gives them;
by the due ordering and disposition of all the Parts that compose the
Edifice, and which she rules by a just Proportion, having regard to a
true _Decorum_, and well regulated _Oeconomy_; from whence it follows,
that Architecture has Eight Parts, _viz._ _Solidity_, _Convenience_,
_Beauty_, _Order_, _Disposition_, _Decorum_, _Oeconomy_.
_Solidity_ depends upon the goodness of the Foundation, choice of
Materials, and the right use of them; which ought to be with a due
order, disposition and convenient Proportion of all Parts together, and
of one in respect of another.
_Convenience_ likewise consists in the ordering and disposition, which
is so good that nothing hinders the use of any part of the Edifice.
_Beauty_ consists in the excellent and agreeable form, and the just
proportion of all its parts.
_Order_ is that which makes, that all the parts of an Edifice have a
convenient bigness, whether we consider them apart or with Relation to
the whole.
_Disposition_ is the orderly Ranging and agreeable Union of all the
parts that compose the Work; so that as Order respects the Greatness,
Disposition respects Form and Situation, which are Two Things compriz'd
under the word _Quality_, which _Vitruvius_ attributes to Disposition,
and opposes to Quantity, which appertains to Order. There are three ways
by which the Architect may take a view beforehand of the Fabrick he is
to build, _viz._ First, _Ichnography_, which is the _Geometrical_ Plan;
_Orthography_, which is the _Geometrical Elevation_, and _Scenography_,
which is _Perspective Elevation_.
_Proportion_, which is also call'd _Eurythmy_, is that which makes the
Union of all parts of the Work, and which renders the Prospect
agreeable, when the Height answers the Breadth, and the Breadth the
Length; every one having its just measure. It is defin'd, the Relation
that all the Work has with its Parts, and which every one of them has
separately to the Idea of the whole, according to the measure of any
Part. For as in Humane Bodies there is a Relation between the Foot,
Hand, Finger and other Parts; so amongst Works that are Perfect, from
any particular Part, we may make a certain Judgment of the Greatness of
the whole Work: For Example, the Diameter of a Pillar, or the Length of
a _Triglyph_, creates in us a right Judgment of the Greatness of the
whole Temple.
And here we must remark, that to express the Relation that many things
have one to another, as to their Greatness or different Number of Parts,
_Vitruvius_ indifferently makes use of three words, which are
_Proportion_, _Eurythmy_ and _Symmetry_. But we have thought it proper
only to make use of the word Proportion, because _Eurythmy_ is a Greek
word, which signifies nothing else but Proportion; and Symmetry,
although a word commonly used, does not signifie in the Vulgar Languages
what _Vitruvius_ understands by Proportion; for he understands by
Proportion, a Relation according to Reason; and Symmetry, in the vulgar
Languages, signifies only, a Relation of Parity and Equality. For the
word _Simmetria_ signifies in Latin and Greek _Relation_ only. As for
Example, as the Relation that Windows of Eight Foot high, have with
other Windows of Six Foot, when the one are Four Foot broad, and the
other Three: and Symmetry, in the Vulgar Languages, signifies the
Relation, for Example, That Windows have one to another, when they are
all of an equal height and equal breadth; and that their Number and
Distances are equal to the Right and the Left; so that if the distances
be unequal of one side, the like inequality is to be found in the other.
Decorum or Decency, is that which makes the Aspect of the Fabrick so
correct, that there is nothing that is not approv'd of, and founded upon
some Authority. It teaches us to have regard to three things, which are,
_Design_, _Custom_ and _Nature_.
The Regard to Design makes us chuse for Example, other Dispositions and
Propertions for a Palace than for a Church.
The Respect we have to Custom, is the Reason, for Example, That the
Porches and Entries of Houses are adorned, when the Inner Parts are Rich
and Magnificent.
The Regard we have to the Nature of Places, makes us chuse different
Prospects for different Parts of the Fabrick, to make them the wholsomer
and the more convenient: For Example, the Bed-Chambers and the Libraries
are exposed to the Morning Sun; the Winter Apartments, to the West; the
Closets or Pictures and other Curiosities, which should always have
equal Light, to the North.
Oeconomy teaches the Architect to have regard to the Expences that are
to be made, and to the Quality of the Materials, near the Places where
he Builds, and to take his Measures rightly for the Order and
Disposition; _viz._ to give the Fabrick a convenient Form and Magnitude.
These Eight Parts, as we have said, have a Relation to the Three first,
_viz._ _Solidity_, _Convenience_, _Beauty_, which suppose, _Order,
Disposition_, _Proportion_, _Decorum_ and _Oeconomy_. This is the reason
that we divide this first Part only into Three Chapters; the first is of
the Solidity; the second of the Convenience; the third of the Beauty of
the Fabrick.