y the Greeks [Greek:
skoteinos] on account of the obscurity of his writings, thought that it
was fire. Democritus and his follower Epicurus thought that it was the
atoms, termed by our writers "bodies that cannot be cut up," or, by
some, "indivisibles." The school of the Pythagoreans added air and the
earthy to the water and fire. Hence, although Democritus did not in a
strict sense name them, but spoke only of indivisible bodies, yet he
seems to have meant these same elements, because when taken by
themselves they cannot be harmed, nor are they susceptible of
dissolution, nor can they be cut up into parts, but throughout time
eternal they forever retain an infinite solidity.

2. All things therefore appear to be made up and produced by the coming
together of these elements, so that they have been distributed by nature
among an infinite number of kinds of things. Hence I believed it right
to treat of the diversity and practical peculiarities of these things as
well as of the qualities which they exhibit in buildings, so that
persons who are intending to build may understand them and so make no
mistake, but may gather materials which are suitable to use in their
buildings.

CHAPTER III

BRICK

1. Beginning with bricks, I shall state of what kind of clay they ought
to be made. They should not be made of sandy or pebbly clay, or of fine
gravel, because when made of these kinds they are in the first place
heavy; and, secondly, when washed by the rain as they stand in walls,
they go to pieces and break up, and the straw in them does not hold
together on account of the roughness of the material. They should rather
be made of white and chalky or of red clay, or even of a coarse grained
gravelly clay. These materials are smooth and therefore durable; they
are not heavy to work with, and are readily laid.

2. Bricks should be made in Spring or Autumn, so that they may dry
uniformly. Those made in Summer are defective, because the fierce heat
of the sun bakes their surface and makes the brick seem dry while inside
it is not dry. And so the shrinking, which follows as they dry, causes
cracks in the parts which were dried before, and these cracks make the
bricks weak. Bricks will be most serviceable if made two years before
using; for they cannot dry thoroughly in less time. When fresh undried
bricks are used in a wall, the stucco covering stiffens and hardens into
a permanent mass, but the bricks settle and cannot ke