The Ten Books on Architecture
convenience, and beauty. Durability will be assured when foundations are
carried down to the solid ground and materials wisely and liberally
selected; convenience, when the arrangement of the apartments is
faultless and presents no hindrance to use, and when each class of
building is assigned to its suitable and appropriate exposure; and
beauty, when the appearance of the work is pleasing and in good taste,
and when its members are in due proportion according to correct
principles of symmetry.
CHAPTER IV
THE SITE OF A CITY
1. For fortified towns the following general principles are to be
observed. First comes the choice of a very healthy site. Such a site
will be high, neither misty nor frosty, and in a climate neither hot nor
cold, but temperate; further, without marshes in the neighbourhood. For
when the morning breezes blow toward the town at sunrise, if they bring
with them mists from marshes and, mingled with the mist, the poisonous
breath of the creatures of the marshes to be wafted into the bodies of
the inhabitants, they will make the site unhealthy. Again, if the town
is on the coast with a southern or western exposure, it will not be
healthy, because in summer the southern sky grows hot at sunrise and is
fiery at noon, while a western exposure grows warm after sunrise, is hot
at noon, and at evening all aglow.
2. These variations in heat and the subsequent cooling off are harmful
to the people living on such sites. The same conclusion may be reached
in the case of inanimate things. For instance, nobody draws the light
for covered wine rooms from the south or west, but rather from the
north, since that quarter is never subject to change but is always
constant and unshifting. So it is with granaries: grain exposed to the
sun's course soon loses its good quality, and provisions and fruit,
unless stored in a place unexposed to the sun's course, do not keep
long.
3. For heat is a universal solvent, melting out of things their power of
resistance, and sucking away and removing their natural strength with
its fiery exhalations so that they grow soft, and hence weak, under its
glow. We see this in the case of iron which, however hard it may
naturally be, yet when heated thoroughly in a furnace fire can be easily
worked into any kind of shape, and still, if cooled while it is soft and
white hot, it hardens again with a mere dip into cold water and takes on
its former quality.
4. We may also recognize the truth of this from the fact that in summer
the heat makes everybody weak, not only in unhealthy but even in healthy
places, and that in winter even the most unhealthy districts are much
healthier because they are given a solidity by the cooling off.
Similarly, persons removed from cold countries to hot cannot endure it
but waste away; whereas those who pass from hot places to the cold
regions of the north, not only do not suffer in health from the change
of residence but even gain by it.
5. It appears, then, that in founding towns we must beware of districts
from which hot winds can spread abroad over the inhabitants. For while
all bodies are composed of the four elements (in Greek [Greek:
stoicheia]), that is, of heat, moisture, the earthy, and air, yet there
are mixtures according to natural temperament which make up the natures
of all the different animals of the world, each after its kind.
6. Therefore, if one of these elements, heat, becomes predominant in any
body whatsoever, it destroys and dissolves all the others with its
violence. This defect may be due to violent heat from certain quarters
of the sky, pouring into the open pores in too great proportion to admit
of a mixture suited to the natural temperament of the body in question.
Again, if too much moisture enters the channels of a body, and thus
introduces disproportion, the other elements, adulterated by the liquid,
are impaired, and the virtues of the mixture dissolved. This defect, in
turn, may arise from the cooling properties of moist winds and breezes
blowing upon the body. In the same way, increase or diminution of the
proportion of air or of the earthy which is natural to the body may
enfeeble the other elements; the predominance of the earthy being due to
overmuch food, that of air to a heavy atmosphere.
7. If one wishes a more accurate understanding of all this, he need only
consider and observe the natures of birds, fishes, and land animals, and
he will thus come to reflect upon distinctions of temperament. One form
of mixture is proper to birds, another to fishes, and a far different
form to land animals. Winged creatures have less of the earthy, less
moisture, heat in moderation, air in large amount. Being made up,
therefore, of the lighter elements, they can more readily soar away into
the air. Fish, with their aquatic nature, being moderately supplied with
heat and made up in great part of air and the earthy, with as little of
moisture as possible, can more easily exist in moisture for the very
reason that they have less of it than of the other elements in their
bodies; and so, when they are drawn to land, they leave life and water
at the same moment. Similarly, the land animals, being moderately
supplied with the elements of air and heat, and having less of the
earthy and a great deal of moisture, cannot long continue alive in the
water, because their portion of moisture is already abundant.
8. Therefore, if all this is as we have explained, our reason showing us
that the bodies of animals are made up of the elements, and these
bodies, as we believe, giving way and breaking up as a result of excess
or deficiency in this or that element, we cannot but believe that we
must take great care to select a very temperate climate for the site of
our city, since healthfulness is, as we have said, the first requisite.
9. I cannot too strongly insist upon the need of a return to the method
of old times. Our ancestors, when about to build a town or an army post,
sacrificed some of the cattle that were wont to feed on the site
proposed and examined their livers. If the livers of the first victims
were dark-coloured or abnormal, they sacrificed others, to see whether
the fault was due to disease or their food. They never began to build
defensive works in a place until after they had made many such trials
and satisfied themselves that good water and food had made the liver
sound and firm. If they continued to find it abnormal, they argued from
this that the food and water supply found in such a place would be just
as unhealthy for man, and so they moved away and changed to another
neighbourhood, healthfulness being their chief object.
10. That pasturage and food may indicate the healthful qualities of a
site is a fact which can be observed and investigated in the case of
certain pastures in Crete, on each side of the river Pothereus, which
separates the two Cretan states of Gnosus and Gortyna. There are cattle
at pasture on the right and left banks of that river, but while the
cattle that feed near Gnosus have the usual spleen, those on the other
side near Gortyna have no perceptible spleen. On investigating the
subject, physicians discovered on this side a kind of herb which the
cattle chew and thus make their spleen small. The herb is therefore
gathered and used as a medicine for the cure of splenetic people. The
Cretans call it [Greek: hasplênon]. From food and water, then, we may
learn whether sites are naturally unhealthy or healthy.
11. If the walled town is built among the marshes themselves, provided
they are by the sea, with a northern or north-eastern exposure, and are
above the level of the seashore, the site will be reasonable enough. For
ditches can be dug to let out the water to the shore, and also in times
of storms the sea swells and comes backing up into the marshes, where
its bitter blend prevents the reproductions of the usual marsh
creatures, while any that swim down from the higher levels to the shore
are killed at once by the saltness to which they are unused. An instance
of this may be found in the Gallic marshes surrounding Altino, Ravenna,
Aquileia, and other towns in places of the kind, close by marshes. They
are marvellously healthy, for the reasons which I have given.
12. But marshes that are stagnant and have no outlets either by rivers
or ditches, like the Pomptine marshes, merely putrefy as they stand,
emitting heavy, unhealthy vapours. A case of a town built in such a spot
was Old Salpia in Apulia, founded by Diomede on his way back from Troy,
or, according to some writers, by Elpias of Rhodes. Year after year
there was sickness, until finally the suffering inhabitants came with a
public petition to Marcus Hostilius and got him to agree to seek and
find them a proper place to which to remove their city. Without delay he
made the most skilful investigations, and at once purchased an estate
near the sea in a healthy place, and asked the Senate and Roman people
for permission to remove the town. He constructed the walls and laid out
the house lots, granting one to each citizen for a mere trifle. This
done, he cut an opening from a lake into the sea, and thus made of the
lake a harbour for the town. The result is that now the people of Salpia
live on a healthy site and at a distance of only four miles from the old
town.
CHAPTER V
THE CITY WALLS
1. After insuring on these principles the healthfulness of the future
city, and selecting a neighbourhood that can supply plenty of food
stuffs to maintain the community, with good roads or else convenient
rivers or seaports affording easy means of transport to the city, the
next thing to do is to lay the foundations for the towers and walls. Dig
down to solid bottom, if it can be found, and lay them therein, going as
deep as the magnitude of the proposed work seems to require. They should
be much thicker than the part of the walls that will appear above
ground, and their structure should be as solid as it can possibly be
laid.
2. The towers must be projected beyond the line of wall, so that an
enemy wishing to approach the wall to carry it by assault may be exposed
to the fire of missiles on his open flank from the towers on his right
and left. Special pains should be taken that there be no easy avenue by
which to storm the wall. The roads should be encompassed at steep
points, and planned so as to approach the gates, not in a straight line,
but from the right to the left; for as a result of this, the right hand
side of the assailants, unprotected by their shields, will be next the
wall. Towns should be laid out not as an exact square nor with salient
angles, but in circular form, to give a view of the enemy from many
points. Defence is difficult where there are salient angles, because the
angle protects the enemy rather than the inhabitants.
3. The thickness of the wall should, in my opinion, be such that armed
men meeting on top of it may pass one another without interference. In
the thickness there should be set a very close succession of ties made
of charred olive wood, binding the two faces of the wall together like
pins, to give it lasting endurance. For that is a material which neither
decay, nor the weather, nor time can harm, but even though buried in the
earth or set in the water it keeps sound and useful forever. And so not
only city walls but substructures in general and all walls that require
a thickness like that of a city wall, will be long in falling to decay
if tied in this manner.
4. The towers should be set at intervals of not more than a bowshot
apart, so that in case of an assault upon any one of them, the enemy may
be repulsed with scorpiones and other means of hurling missiles from the
towers to the right and left. Opposite the inner side of every tower the