eeds across upon the
former, and another Bed of fat Earth or Clay, upon which they laid Beds
of Mortar and Stuck, as we have said before.

[Sidenote: _Lib. 7. Chap. 4._]

For the Plastering of low and moist places, they had a great many other
Precautions, especially within the House; for as what belonged to the
Out-part of the House, they contented themselves to Plaster from the
Bottom of the Wall to the height of three Feet, with Cement.

But as to the Inward-parts of the House, when the Ground without was
higher than the lowermost Flooring; they run up a little narrow Wall
against the great one, leaving betwixt the two Walls only the distance
of a Channel or Sewer, which they made lower than the Flooring, to
receive the Water which might be gather'd against the Walls, and let it
run out; and to the End they might hinder the gathering of much Water,
by the Vapours which might be enclosed between these two Walls, they
made towards the top of the little Wall Vents to let it out, and this
little Wall was Plastered on the Out-side with Mortar and Stuck, as we
have said before.

When the Place was too narrow to permit those Counter-Walls to be made
within, they put hollow Tiles one upon another against the Wall, and
placed and plaster'd them over with Mortar and Stuck. These Tiles which
were Pitch'd over within, and were Demi-Channels, let the Water fall
down into the Sewer, which sweat from the great Wall, and so let all the
Vapours, which were engendred by Humidity, go out at the Vents.

CHAP. III.

_Of the Convenience of Fabricks_.

ARTICLE I.

[Sidenote: _Lib. 2. Praes._]

One of the Principal Things the Architect ought to consider, is the
Convenience of the place where he would Build the Fabrick. This is the
reason that _Dinocrates_ was blamed by _Alexander_, for having propos'd
him an Excellent Design for Building a City in a Barren place, and
incapable of Nourishing those who were to Inhabit it.

We must then choose a place that is fertile, and hath abundance of every
thing; and which hath likewise Rivers and Ports capable of furnishing
it with all the Product and Commodities of the adjacent Countries.

The Third thing to be considered is, whether the Air be wholesome; and
for this End, we must choose a high situated place, that it may be less
Subject to Fogs and Mists; it must be likewise far from all Morasses,
because the Corruption that may be caused by the infectious Breath of
Venomous Beast