Archimedes Texts

52
with Oil, it grows pale; wash'd with Red
Wine, it turns of a dirty brown; with Water,
kept some time in Chessnut-wood, it changes
quite thro' to black, and is so totally stain'd,
that no scraping will fetch out the Spots. For
this Reason the Ancients used Marble in their
Works naked, and if possible without the
least Mortar: But of these hereafter.

Of the true Manner of Working the Wall, and of the Agreement there is be
tween Stone and Sand.

Now as it is the Business of an expert
Workman, not so much to make
Choice of the fittest Materials, as to put those
which he is supplied with to the best and
properest Uses; we will proceed on our Sub
ject in this Manner. Lime is well burnt, when
after it has been water'd, and the Heat gone
out of it, it rises up like the Froth of Milk,
and swells all the Clods. Its not having been
long enough soak'd you may know by the little
Stones you will find in it when you mix the
Sand with it. If you put too much Sand to it,
it will be too sharp to cement well; if you
put less than its Nature and Strength requires,
it will be as stiff as Glue, and is not to be
managed. Such as is not thoroughly soak'd,
or that is weaker upon any other Account,
may be used with less Danger in the Foundation
than in the Wall, and in the Stuffing than in
Shells. But the Corners, the Ribs, and the
Band-stones must be entirely free from Mortar
that has the least Defect; and Arches especi
ally require the very best of all. The Corners,
and Ribs, and the Band-stones, and Cornices
require the finest, smallest and clearest Sand,
particularly when they are built of polished
Stone. The Stuffing may be done with
coarser Stone.

STONE in its Nature dry and thirsty, agrees
not ill with River-sand. Stone in its Nature
moist and watery, delights in Pit-sand. I
would not have Sea-sand used towards the
South; it may perhaps do better against the
Northern Winds. For small Stones, a thick
lean Mortar is best; to a dry exhausted Stone,
we should use a fat Sort; though the Ancients
were of Opinion that in all Parts of the Walls
the fattish Sort is more tenacious than the lean.
Great Stones they always lay upon a very soft
fluid Mortar, so that it rather seems design'd
to lubricate and make the Bed they are laid
upon slippery, to the Intent, that while they
are fixing in their Places they may be easy to
move with the Hand, then to cement and
fasten them together. But it is certainly proper
to lay a soft Stuff underneath in this Manner,
like a Pillow, to prevent the Stones, which
have a great Weight lying upon them, from
breaking. There are some, who observing
here and there in the Works of the Ancients,
large Stones, which where they join seem
dawb'd over with red Earth, imagine that the
Ancients used that instead of Mortar. I do
not think this probable, because we never find
both Sides, but only one of them, smear'd
with this Sort of Stuff. There are some other
Rules concerning the Working of our Walls,
not to be neglected. We ought never to fall
upon our Work with a violent Haste, heaping
one Stone upon another, in a Kind tumul
tuousHurry, without the least Respite: Neither
ought we, after we have began to build, to
delay it with a sluggish Heaviness, as if we had
no Stomach to what we are about; but we
ought to follow our Work with such a reason
able Dispatch, that Speed and Consideration
may appear to go Hand in Hand together.
Experienced Workmen forewarn us against
raising the Structure too high, before what we
have already done is thoroughly settled; be
cause the Work, while it is fresh and soft, is
too weak and pliable to bear a Superstructure.
We may take Example from the Swallows,
taught by Nature, which when they build
their Nests, first dawb or glue over the Beams
which are to be the Foundation and Basis of
their Edifice, and then are not too hasty to
lay the second dawbing over this, but inter
mit the Work till the first is sufficiently dry'd;
after which they continue their Building reason
ably and properly. They say the Mortar has
taken sufficient hold when it puts forth a Kind
of Moss or little Flower well known to Masons.
At what Distances it is proper to respite the
we may gather from the Thickness of the
Wall itself, and from the Temperature of the