ell offhand whether it is of
the best or unfit to use in a wall, because its strength can be tested
only after it has been used on a roof and exposed to bad weather and
time--then, if it is good it is accepted. If not made of good clay or if
not baked sufficiently, it shows itself defective there when exposed to
frosts and rime. Brick that will not stand exposure on roofs can never
be strong enough to carry its load in a wall. Hence the strongest burnt
brick walls are those which are constructed out of old roofing tiles.

20. As for "wattle and daub" I could wish that it had never been
invented. The more it saves in time and gains in space, the greater and
the more general is the disaster that it may cause; for it is made to
catch fire, like torches. It seems better, therefore, to spend on walls
of burnt brick, and be at expense, than to save with "wattle and daub,"
and be in danger. And, in the stucco covering, too, it makes cracks from
the inside by the arrangement of its studs and girts. For these swell
with moisture as they are daubed, and then contract as they dry, and, by
their shrinking, cause the solid stucco to split. But since some are
obliged to use it either to save time or money, or for partitions on an
unsupported span, the proper method of construction is as follows. Give
it a high foundation so that it may nowhere come in contact with the
broken stone-work composing the floor; for if it is sunk in this, it
rots in course of time, then settles and sags forward, and so breaks
through the surface of the stucco covering.

I have now explained to the best of my ability the subject of walls, and
the preparation of the different kinds of material employed, with their
advantages and disadvantages. Next, following the guidance of Nature, I
shall treat of the framework and the kinds of wood used in it, showing
how they may be procured of a sort that will not give way as time goes
on.

CHAPTER IX

TIMBER

1. Timber should be felled between early Autumn and the time when
Favonius begins to blow. For in Spring all trees become pregnant, and
they are all employing their natural vigour in the production of leaves
and of the fruits that return every year. The requirements of that
season render them empty and swollen, and so they are weak and feeble
because of their looseness of texture. This is also the case with women
who have conceived. Their bodies are not considered perfectly healthy
until the child is