and then bind them to
the fronts by means of iron clamps and lead. For thus his work, being no
mere heap of material but regularly laid in courses, will be strong
enough to last forever without a flaw, because the beds and builds, all
settling equally and bonded at the joints, will not let the work bulge
out, nor allow the fall of the face walls which have been tightly
fastened together.

5. Consequently, the method of construction employed by the Greeks is
not to be despised. They do not use a structure of soft rubble polished
on the outside, but whenever they forsake dimension stone, they lay
courses of lava or of some hard stone, and, as though building with
brick, they bind the upright joints by interchanging the direction of
the stones as they lie in the courses. Thus they attain to a perfection
that will endure to eternity. These structures are of two kinds. One of
them is called "isodomum," the other "pseudisodomum."

6. A wall is called isodomum when all the courses are of equal height;
pseudisodomum, when the rows of courses do not match but run unequally.
Both kinds are strong: first, because the rubble itself is of close
texture and solid, unable to suck the moisture out of the mortar, but
keeping it in its moist condition for a very long period; secondly,
because the beds of the stones, being laid smooth and level to begin
with, keep the mortar from falling, and, as they are bonded throughout
the entire thickness of the wall, they hold together for a very long
period.

7. Another method is that which they call [Greek: emplekton], used also
among us in the country. In this the facings are finished, but the other
stones left in their natural state and then laid with alternate bonding
stones. But our workmen, in their hurry to finish, devote themselves
only to the facings of the walls, setting them upright but filling the
space between with a lot of broken stones and mortar thrown in anyhow.
This makes three different sections in the same structure; two
consisting of facing and one of filling between them. The Greeks,
however, do not build so; but laying their stones level and building
every other stone length-wise into the thickness, they do not fill the
space between, but construct the thickness of their walls in one solid
and unbroken mass from the facings to the interior. Further, at
intervals they lay single stones which run through the entire
thickness of the wall. These stones, which show at each end,