Archimedes Texts

61
with Rims of each Side, a ninth Part of its
Breadth, which is call'd a Gutter-tile; the
other round, like Greaves, (a Piece of Armour
for the Legs,) which is called a Ridge-tile;
both broader in that Part which is to receive
the Rain, and narrower in that from which
they are to discharge it. But the Plain, or
Gutter-tiles are the most Commodius, pro
vided they are laid exactly even, so as not to
lean of either Side, nor to make either Vallies
or Hilocks to stop the Current of the Water,
or to let it settle in, nor to leave any Cranny
uncover'd. If the Superficies of the Roof is
very large, it requires bigger Gutter-tiles, that
the Rain may not overflow them for want of
a sufficient Receptacle. To prevent the Fury
of the Wind from ripping off the Tiles, I
would have them all fastened with Mortar;
especially in publick Buildings: But in private
Ones, it will be enough if you secure only the
Gutter-tiles from that Violence, because what
ever Mischief is done, is easily repair'd. There
is another very convenient Way of Tiling, in
this Manner: If in Timber Roofs, instead of
Planks, you lay along the Girders Squares of
baked Clay, fasten'd with Plaister of Paris, and
over these Squares lay your Tiles with Mortar,
it will be a Covering very secure against Fire,
and very commodious to the Inhabitants; and
it will be less expensive, if, instead of Squares,
you underlay it with Reeds, bound with Mor
tar. I would not have you use your Tiles,
and especially those which you lay with Mor
tar, in publick Works, till they have supported
the Frost and Sun two Years; because, if you
happen to use any bad ones, there is no taking
them out again without a good deal of
Trouble and Expence. It may not be amiss
here to mention what I have read in Diodorus
the Historian, relating to the famous hanging
Gardens in Syria, which were contrived with
a new, and not unuseful Invention: For upon
the Beams they laid Rushes dawb'd over with
Pitch, and on these two Rows of baked
Bricks, one above the other, cemented with
Mortar; and in the third Place, they laid
Plates of Lead so disposed, and fasten'd to
gether, that not the least wet could penetrate
to the Brick.

Of Pavements according to the Opinion of Pliny and Vitruvius, and the Works
of the Ancients; and of the proper Seasons for Beginning and Finishing
the several Parts of Building.

We come now to treat of Pavements,
which also partake somewhat of the
Nature of Coverings. Of these, some are
open to the Air; others are laid upon Rafters
and Boards, others not: All require for their
Foundation a solid, and even Superficies, laid
exactly according to their proper Lines. Those
which are open to the Air ought to be raised
in such a Manner, that every ten Foot may
have a Declivity of, at least, two Inches, to
throw off the Water, which ought to be con
veyed from thence either into Cisterns or
Sinks. If from these Sinks you have not the
Conveniency of a Drain, either into the Sea,
or some River, dig Pits for the Soil in conve
nient Places, so deep as to come to some Spring
of Water, and then fill up those Pits with
round Pebbles.

LASTLY, if you have no Opportunity to
do this, make good large Sinks, and fling
Coals into them, and then fill them up with
Sand, which will suck up, and dry away the
superfluous Moisture. If the Superficies that
your Pavement is to be laid upon, is a soft
loose Earth, ram it soundly, and lay it over
with broken Fragments of Stone, well beat in
with the Rammer also: But if the Pavement
is to be upon Rafters, cover them over with
Boards, and upon them lay your Rubbish or
Fragments of Stone a Foot high, and beaten
together, and consolidated with the Rammer.
Some are of Opinion, that under these we
ought to lay Fern, or Spart, to keep the Mor
tar from rotting the Timber. If your Rub
bish is of new Stone, allow one Part of Mortar
to three of Rubbish; if it is of old, you must
allow two Parts in five; and when it is laid,
the Way to stiffen it, is to pound it heartily
with the Rammer. Over these you lay a
Plaister six Inches high, made of broken
Tiles, or Bricks pounded, mix'd with one
fourth Part of Mortar; and upon this, lastly,
you lay your Pavement, of whatsoever Sort it
is, whether of Brick or Tile, exactly by Rule