that Knowledge of this Art which is acquired by
study, travelling and discourse. The Practick is that knowledge that is
acquired by the Actual Building of great Fabricks. These Two Parts are
so necessary, that never any came to any great Perfection without them
both. The one being lame and imperfect without the other, so they must
walk hand in hand.

Besides, the Knowledge of things that particularly belong to
Architecture, there are infinite other things that are necessary to be
known by an Architect.

For, First, it's necessary that he be able to couch in writing his
intended Building, and to design the Plan, and make an excellent Model
of it.

Geometry likewise is very necessary for him in many occasions.

He must also know Arithmetick to make a true Calculation.

He must be knowing in History, and be able to give a reason for the
greatest part of the Ornaments of Architecture which are founded upon
History. For Example, if instead of Pillars he support the Floors of the
House with the figures of Women, which are called _Cariatides_, he ought
to know that the _Greeks_ invented these Figures to let Posterity know
the Victories they obtained over the _Cariens_, whose Wives they made
Captives, and put their Images in their Buildings.

It's necessary likewise, that he be instructed in the Precepts of Moral
Philosophy; for he ought to have a great Soul, and be bold without
Arrogance, just, faithful, and totally exempt from Avarice.

[Sidenote: _Lib. 1. Chap. 11._]

The Architect also ought to have a great Docility which may hinder him
from neglecting the advice that is given him, not only by the meanest
Artist, but also by those that understand nothing of Architecture; for
not only Architects, but all the World must judge of his Works.

[Sidenote: _Lib. 1. Chap. 2._]

Natural Philosophy is likewise necessary for him for to discover what
are the Causes of many things which he must put a remedy to.

He ought also to know something of _Physick_, to know the qualities of
the Air, which makes Places Healthful and Habitable, or the quite
contrary.

He should not be ignorant of the Laws and the Customs of Places for the
Building of Partition Walls, for prospect and for the conveying of
Waters and Sewers.

He ought to know _Astronomy_, that he may be able to make all sorts of
Dials.

It was necessary among the Ancients, that an Architect should have skill
in _Musick_ to make and order _Catapults_ and other Machi