l; they
ought likewise to have an _Emparement_ or large Foundation which must be
equal to the height of the Wall, so that they go diminishing by degrees
from the bottom to the top, where they come to equal the height of the
Wall.

[Sidenote: _Lib. 1. Chap. 5._]

The effect of these _Buttresses_ is not only to support the Earth by
their Resistance, but likewise to lessen its Efforts when it swells, in
dividing it into many parts.

[Sidenote: _Lib. 6. Chap. 11._]

And if it be judg'd that these _Buttresses_ be not sufficient, the Wall
also which supports the Earth must be strengthned with other
_Buttresses_ within.

ART. V.

_Of Flooring and Ceiling._

There are four sorts of Flooring, some are upon the _Superficies_ of the
Ground, others between two Stories, others make the Roof of the House in
Plat-form, and the last is _Plat-Fond_.

To make those Floors that are upon the Ground, you must first make the
Earth smooth and plain, if it be firm and solid, if not, it must be
beaten with a Rammer with which they ram down their Piles; and after
having cover'd the Earth with the first _Lay_ or _Bed_, call'd
_Statumen_ by the Ancients, which was of Flinty Stones about the bigness
of ones Fist, among which was mixed Mortar made of Lime and Sand. Then
they laid the second _Bed_, which they call'd _Rudus_, which was made of
lesser Stones, of which there were three Parts for one of Stone if they
were new, for if they were taken out of old Buildings, five parts of
Stones or Pibbles would be required for two of Lime.

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

The _Greeks_ had a way of making their Floors in those low places where
cold and humidity ordinarily reign, which freed them from these
Inconveniences. They digged the Earth two Foot deep, and after having
beaten it well, they laid a Bed of Mortar or Cement a little sloping
from either side to the Channel, which convey'd the Water under Ground;
they laid a Bed of Coal upon the first Mortar, and having beaten them
well, they cover'd them with another Cement or Mortar made of Lime, Sand
and Ashes, which they made smooth when it was dry with a
Polishing-Stone. These Floors presently drank up the Water that fell
upon them, that one might walk barefoot without being incommoded by the
Cold.

For the Floors which are between two Stories, there must be a particular
care taken, that if there be any Partition below it, that it may not
touch the Flooring for fear lest if the Floori