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Vitruvius
The Ten Books on Architecture
Book II
Introduction
1. Dinocrates, an architect who was full of confidence in his own ideas
and skill, set out from Macedonia, in the reign of Alexander, to go to
the army, being eager to win the approbation of the king. He took with
him from his country letters from relatives and friends to the principal
military men and officers of the court, in order to gain access to them
more readily. Being politely received by them, he asked to be presented
to Alexander as soon as possible. They promised, but were rather slow,
waiting for a suitable opportunity. So Dinocrates, thinking that they were
playing with him, had recourse to his own efforts. He was of very lofty
stature and pleasing countenance, finely formed, and extremely dignified.
Trusting, therefore, to these natural gifts, he undressed himself in his
inn, anointed his body with oil, set a chaplet of poplar leaves on his
head, draped his left shoulder with a lion's skin, and holding a club in
his right hand stalked forth to a place in front of the tribunal where
the king was administering justice.
2. His strange appearance made the people turn round, and this led Alexander
to look at him. In astonishment he gave orders to make way for him to draw
near, and asked who he was. "Dinocrates," quoth he, "a Macedonian architect,
who brings thee ideas and designs worthy of thy renown. I have made a design
for the shaping of Mount Athos into the statue of a man, in whose left
hand I have represented a very spacious fortified city, and in his right
a bowl to receive the water of all the streams which are in that mountain,
so that it may pour from the bowl into the sea."
3. Alexander, delighted with the idea of his design, immediately inquired
whether there were any fields in the neighborhood that could maintain the
city in corn. On finding that this was impossible without transport from
beyond the sea, "Dinocrates," quoth he, "I appreciate your design as excellent
in composition, and I am delighted with it, but I apprehend that anybody
who should found a city in that spot would be censured for bad judgment.
For as a newborn babe cannot be nourished without the nurse's milk, nor
conducted to the approaches that lead to growth in life, so a city cannot
thrive without fields and the fruits thereof pouring into its walls, nor
have a large population without plenty of food, nor maintain its population
without a supply of it. Therefore, while thinking that your design is commendable,
I consider the site as not commendable; but I would have you stay with
me, because I mean to make use of your services."
4. From that time, Dinocrates did not leave the king, but followed him
into Egypt. There Alexander, observing a harbor rendered safe by nature,
an excellent center for trade, cornfields throughout all Egypt, and the
great usefulness of the mighty river Nile, ordered him to build the city
of Alexandria, named after the king. This was how Dinocrates, recommended
only by his good looks and dignified carriage, came to be so famous. But
as for me, Emperor, nature has not given me stature, age has marred my
face, and my strength is impaired by ill health. Therefore, since these
advantages fail me, I shall win your approval, as I hope, by the help of
my knowledge and my writings.
5. In my first book, I have said what I had to say about the functions
of architecture and the scope of the art, as well as about fortified towns
and the apportionment of building sites within the fortifications. Although
it would next be in order to explain the proper proportions and symmetry
of temples and public buildings, as well as of private houses, I thought
best to postpone this until after I had treated the practical merits of
the materials out of which, when they are brought together, buildings are
constructed with due regard to the proper kind of material for each part,
and until I had shown of what natural elements those materials are composed.
But before beginning to explain their natural properties, I will prefix
the motives which originally gave rise to buildings and the development
of inventions in this field, following in the steps of early nature and
of those writers who have devoted treatises to the origins of civilization
and the investigation of inventions. My exposition will, therefore, follow
the instruction which I have received from them.
CHAPTER I
The Origin of the Dwelling House
1. The men of old were born like the wild beasts, in woods, caves, and
groves, and lived on savage fare. As time went on, the thickly crowded
trees in a certain place, tossed by storms and winds, and rubbing their
branches against one another, caught fire, and so the inhabitants of the
place were put to flight, being terrified by the furious flame. After it
subsided, they drew near, and observing that they were very comfortable
standing before the warm fire, they put on logs and, while thus keeping
it alive, brought up other people to it, showing them by signs how much
comfort they got from it. In that gathering of men, at a time when utterance
of sound was purely individual, from daily habits they fixed upon articulate
words just as these had happened to come; then, from indicating by name
things in common use, the result was that in this chance way they began
to talk, and thus originated conversation with one another.
2. Therefore it was the discovery of fire that originally gave rise
to the coming together of men, to the deliberative assembly, and to social
intercourse. And so, as they kept coming together in greater numbers into
one place, finding themselves naturally gifted beyond the other animals
in not being obliged to walk with faces to the ground, but upright and
gazing upon the splendor of the starry firmament, and also in being able
to do with ease whatever they chose with their hands and fingers, they
began in that first assembly to construct shelters. Some made them of green
boughs, others dug caves on mountain sides, and some, in imitation of the
nests of swallows and the way they built, made places of refuge out of
mud and twigs. Next, by observing the shelters of others and adding new
details to their own inceptions, they constructed better and better kinds
of huts as time went on.
3. And since they were of an imitative and teachable nature, they would
daily point out to each other the results of their building, boasting of
the novelties in it; and thus, with their natural gifts sharpened by emulation,
their standards improved daily. At first they set up forked stakes connected
by twigs and covered these walls with mud. Others made walls of lumps of
dried mud, covering them with reeds and leaves to keep out the rain and
the heat. Finding that such roofs could not stand the rain during the storms
of winter, they built them with peaks daubed with mud, the roofs sloping
and projecting so as to carry off the rain water.
4. That houses originated as I have written above, we can see for ourselves
from the buildings that are to this day constructed of like materials by
foreign tribes: for instance, in Gaul, Spain, Portugal, and Aquitaine,
roofed with oak shingles or thatched. Among the Colchians in Pontus, where
there are forests in plenty, they lay down entire trees flat on the ground
to the right and the left, leaving between them a space to suit the length
of the trees, and then place above these another pair of trees, resting
on the ends of the former and at right angles with them. These four trees
enclose the space for the dwelling. Then upon these they place sticks of
timber, one after the other on the four sides, crossing each other at the
angles, and so, proceeding with their walls of trees laid perpendicularly
above the lowest, they build up high towers. The interstices, which are
left on account of the thickness of the building material, are stopped
up with chips and mud. As for the roofs, by cutting away the ends of the
crossbeams and making them converge gradually as they lay them across,
they
bring them up to the top from the four sides in the shape of a pyramid.
They cover it with leaves and mud, and thus construct the roofs of their
towers in a rude form of the "tortoise" style.
5. On the other hand, the Phrygians, who live in an open country, have
no forests and consequently lack timber. They therefore select a natural
hillock, run a trench through the middle of it, dig passages, and extend
the interior space as widely as the site admits. Over it they build a pyramidal
roof of logs fastened together, and this they cover with reeds and brushwood,
heaping up very high mounds of earth above their dwellings. Thus their
fashion in houses makes their winters very warm and their summers very
cool. Some construct hovels with roofs of rushes from the swamps. Among
other nations, also, in some places there are huts of the same or a similar
method of construction. Likewise at Marseilles we can see roofs without
tiles, made of earth mixed with straw. In Athens on the Areopagus there
is to this day a relic of antiquity with a mud roof. The hut of Romulus
on the Capitol is a significant reminder of the fashions of old times,
and likewise the thatched roofs of temples or the Citadel.
6. From such specimens we can draw our inferences with regard to the
devices used in the buildings of antiquity, and conclude that they were
similar. Furthermore, as men made progress by becoming daily more expert
in building, and as their ingenuity was increased by their dexterity so
that from habit they attained to considerable skill, their intelligence
was enlarged by their industry until the more proficient adopted the trade
of carpenters. From these early beginnings, and from the fact that nature
had not only endowed the human race with senses like the rest of the animals,
but had also equipped their minds with the powers of thought and understanding,
thus putting all other animals under their sway, they next gradually advanced
from the construction of buildings to the other arts and sciences, and
so passed from a rude and barbarous mode of life to civilization and refinement.
7. Then, taking courage and looking forward from the standpoint of higher
ideas born of the multiplication of the arts, they gave up huts and began
to build houses with foundations, having brick or stone walls, and roofs
of timber and tiles; next, observation and application led them from fluctuating
and indefinite conceptions to definite rules of symmetry. Perceiving that
nature had been lavish in the bestowal of timber and bountiful in stores
of building material, they treated this like careful nurses, and thus developing
the refinements of life, embellished them with luxuries. Therefore I shall
now treat, to the best of my ability, of the things which are suitable
to be used in buildings, showing their qualities and their excellencies.
8. Some persons, however, may find fault with the position of this book,
thinking that it should have been placed first. I will therefore explain
the matter, lest it be thought that I have made a mistake. Being engaged
in writing a complete treatise on architecture, I resolved to set forth
in the first book the branches of learning and studies of which it consists,
to define its departments, and to show of what it is composed. Hence I
have there declared what the qualities of an architect should be. In the
first book, therefore, I have spoken of the function of the art, but in
this I shall discuss the use of the building materials which nature provides.
For this book does not show of what architecture is composed, but treats
of the origin of the building art, how it was fostered, and how it made
progress, step by step, until it reached its present perfection.
9. This book is, therefore, in its proper order and place. I will now
return to my subject, and with regard to the materials suited to the construction
of buildings will consider their natural formation and in what proportions
their elementary constituents were combined, making it all clear and not
obscure to my readers. For there is no kind of material, no body, and no
thing that can be produced or conceived of, which is not made up of elementary
particles; and nature does not admit of a truthful exploration in accordance
with the doctrines of the physicists without an accurate demonstration
of the primary causes of things, showing how and why they are as they are.
Chapter II
On the Primordial Substance According to the Physicists
1. First of all Thales thought that water was the primordial substance
of all things. Heraclitus of Ephesus 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 keep the same height as the stucco; the
motion caused by their shrinking prevents them from adhering to it, and
they are separated from their union with it. Hence the stucco, no longer
joined to the core of the wall, cannot stand by itself because it is so
thin; it breaks off, and the walls themselves may perhaps be ruined by
their settling. This is so true that at Utica in constructing walls they
use brick only if it is dry and made five years previously, and approved
as such by the authority of a magistrate.
3. There are three kinds of bricks. First, the kind called in Greek
Lydian, being that which our people use, a foot and a half long and one
foot wide. The other two kinds are used by the Greeks in their buildings.
A brick five palms square is called "pentadoron"; one four palms square
"tetradoron."
4. With these bricks there are also half bricks. When these are used
in a wall, a course of bricks is laid on one face and a course of half
bricks on the other, and they are bedded to the line on each face. The
walls are bonded by alternate courses of the two different kinds, and as
the bricks are always laid so as to break joints, this lends strength and
a not unattractive appearance to both sides of such walls. In the states
of Maxilua and Callet, in Further Spain, as well as in Pitane in Asia Minor,
there are bricks which, when finished and dried, will float on being thrown
into water. The reason why they can float seems to be that the clay of
which they are made is like pumice stone. So it is light, and also it does
not, after being hardened by exposure to the air, take up or absorb liquid.
So these bricks, being of this light and porous quality, and admitting
no moisture into their texture, must by the laws of nature float in water,
like pumice, no matter what their weight may be. They have therefore great
advantages; for they are not heavy to use in building and, once made, they
are not spoiled by bad weather.
Chapter IV
Sand
1. In walls of masonry the first question must be with regard to the sand,
in order that it may be fit to mix into mortar and have no dirt in it.
The kinds of pit sand are these: black, gray, red, and carbuncular. Of
these the best will be found to be that which crackles when rubbed in the
hand, while that which has much dirt in it will not be sharp enough. Again:
throw some sand upon a white garment and then shake it out; if the garment
is not soiled and no dirt adheres to it, the sand is suitable.
2. But if there are no sandpits from which it can be dug, then we must
sift it out from river beds or from gravel or even from the sea beach.
This kind, however, has these defects when used in masonry: it dries slowly;
the wall cannot be built up without interruption but from time to time
there must be pauses in the work; and such a wall cannot carry vaultings.
Furthermore, when sea sand is used in walls and these are coated with stucco,
a salty efflorescence is given out which spoils the surface.
3. But pit sand used in masonry dries quickly, the stucco coating is
permanent, and the walls can support vaultings. I am speaking of sand fresh
from the sandpits. For if it lies unused too long after being taken out,
it is disintegrated by exposure to sun, moon, or hoar frost, and becomes
earthy. So when mixed in masonry, it has no binding power on the rubble,
which consequently settles and down comes the load which the walls can
no longer support. Fresh pit sand, however, in spite of all its excellence
in concrete structures, is not equally useful in stucco, the richness of
which, when the lime and straw are mixed with such sand, will cause it
to crack as it dries on account of the great strength of the mixture. But
river sand, though useless in "signinum" on account of its thinness, becomes
perfectly solid in stucco when thoroughly worked by means of polishing
instruments.
Chapter V
Lime
1. Sand and its sources having been thus treated, next with regard to lime
we must be careful that it is burned from a stone which, whether soft or
hard, is in any case white. Lime made of close grained stone of the harder
sort will be good in structural parts; lime of porous stone, in stucco.
After slaking it, mix your mortar, if using pit sand, in the proportions
of three parts of sand to one of lime; if using river or sea sand, mix
two parts of sand with one of lime. These will be the right proportions
for the composition of the mixture. Further, in using river or sea sand,
the addition of a third part composed of burnt brick, pounded up and sifted,
will make your mortar of a better composition to use.
2. The reason why lime makes a solid structure on being combined with
water and sand seems to be this: that rocks, like all other bodies, are
composed of the four elements. Those which contain a larger proportion
of air, are soft; of water, are tough from the moisture; of earth, hard;
and of fire, more brittle. Therefore, if limestone, without being burned,
is merely pounded up small and then mixed with sand and so put into the
work, the mass does not solidify nor can it hold together. But if the stone
is first thrown into the kiln, it loses its former property of solidity
by exposure to the great heat of the fire, and so with its strength burnt
out and exhausted it is left with its pores open and empty. Hence, the
moisture and air in the body of the stone being burned out and set free,
and only a residuum of heat being left lying in it, if the stone is then
immersed in water, the moisture, before the water can feel the influence
of the fire, makes its way into the open pores; then the stone begins to
get hot, and finally, after it cools off, the heat is rejected from the
body of the lime.
3. Consequently, limestone when taken out of the kiln cannot be as heavy
as when it was thrown in, but on being weighed, though its bulk remains
the same as before, it is found to have lost about a third of its weight
owing to the boiling out of the water. Therefore, its pores being thus
opened and its texture rendered loose, it readily mixes with sand, and
hence the two materials cohere as they dry, unite with the rubble, and
make a solid structure.
Chapter VI
Pozzolana
1. There is also a kind of powder which from natural causes produces
astonishing results. It is found in the neighborhood of Baiae and in the
country belonging to the towns round about Mt. Vesuvius. This substance,
when mixed with lime and rubble, not only lends strength to buildings of
other kinds, but even when piers of it are constructed in the sea, they
set hard under water. The reason for this seems to be that the soil on
the slopes of the mountains in these neighborhoods is hot and full of hot
springs. This would not be so unless the mountains had beneath them huge
fires of burning sulfur or alum or asphalt. So the fire and the heat of
the flames, coming up hot from far within through the fissures, make the
soil there light, and the tufa found there is spongy and free from moisture.
Hence, when the three substances, all formed on a similar principle by
the force of fire, are mixed together, the water suddenly taken in makes
them cohere, and the moisture quickly hardens them so that they set into
a mass which neither the waves nor the force of the water can dissolve.
2. That there is burning heat in these regions may be proved by the
further fact that in the mountains near Baiae, which belongs to the Cumaeans,
there are places excavated to serve as sweating baths, where the intense
heat that comes from far below bores its way through the earth, owing to
the force of the fire, and passing up appears in these regions, thus making
remarkably good sweating baths. Likewise also it is related that in ancient
times the tides of heat, swelling and overflowing from under Mt. Vesuvius,
vomited forth fire from the mountain upon the neighboring country. Hence,
what is called "sponge stone" or "Pompeian pumice" appears to have been
reduced by burning from another kind of stone to the condition of the kind
which we see.
3. The kind of sponge stone taken from this region is not produced everywhere
else, but only about Aetna and among the hills of Mysia which the Greeks
call the "Burnt District," and in other places of the same peculiar nature.
Seeing that in such places there are found hot springs and warm vapor in
excavations on the mountains, and that the ancients tell us that there
were once fires spreading over the fields in those very regions, it seems
to be certain that moisture has been extracted from the tufa and earth,
by the force of fire, just as it is from limestone in kilns.
4. Therefore, when different and unlike things have been subjected to
the action of fire and thus reduced to the same condition, if after this,
while in a warm, dry state, they are suddenly saturated with water, there
is an effervescence of the heat latent in the bodies of them all, and this
makes them firmly unite and quickly assume the property of one solid mass.
There will still be the question why Tuscany, although it abounds in
hot springs, does not furnish a powder out of which, on the same principle,
a wall can be made which will set fast under water. I have therefore thought
best to explain how this seems to be, before the question should be raised.
5. The same kinds of soil are not found in all places and countries
alike, nor is stone found everywhere. Some soils are earthy; others gravelly,
and again pebbly; in other places the material is sandy; in a word, the
properties of the soil are as different and unlike as are the various countries.
In particular, it may be observed that sandpits are hardly ever lacking
in any place within the districts of Italy and Tuscany which are bounded
by the Apennines; whereas across the Apennines toward the Adriatic none
are found, and in Achaea and Asia Minor or, in short, across the sea, the
very term is unknown. Hence it is not in all the places where boiling springs
of hot water abound, that there is the same combination of favorable circumstances
which has been described above. For things are produced in accordance with
the will of nature; not to suit man's pleasure, but as it were by a chance
distribution.
6. Therefore, where the mountains are not earthy but consist of soft
stone, the force of the fire, passing through the fissures in the stone,
sets it afire. The soft and delicate part is burned out, while the hard
part is left. Consequently, while in Campania the burning of the earth
makes ashes, in Tuscany the combustion of the stone makes carbuncular sand.
Both are excellent in walls, but one is better to use for buildings on
land, the other for piers under salt water. The Tuscan stone is softer
in quality than tufa but harder than earth, and being thoroughly kindled
by the violent heat from below, the result is the production in some places
of the kind of sand called carbuncular.
Chapter VII
Stone
1. I have now spoken of lime and sand, with their varieties and points
of excellence. Next comes the consideration of stone quarries from which
dimension stone and supplies of rubble to be used in building are taken
and brought together. The stone in quarries is found to be of different
and unlike qualities. In some it is soft: for example, in the environs
of the city at the quarries of Grotta Rossa, Palla, Fidenae, and of the
Alban hills; in others, it is medium, as at Tivoli, at Amiternum, or Mt.
Soracte, and in quarries of this sort; in still others it is hard, as in
lava quarries. There are also numerous other kinds: for instance, in Campania,
red and black tufas; in Umbria, Picenum, and Venetia, white tufa which
can be cut with a toothed saw, like wood.
2. All these soft kinds have the advantage that they can be easily worked
as soon as they have been taken from the quarries. Under cover they play
their part well; but in open and exposed situations the frost and rime
make them crumble, and they go to pieces. On the seacoast, too, the salt
eats away and dissolves them, nor can they stand great heat either. But
travertine and all stone of that class can stand injury whether from a
heavy load laid upon it or from the weather; exposure to fire, however,
it cannot bear, but splits and cracks to pieces at once. This is because
in its natural composition there is but little moisture and not much of
the earthy, but a great deal of air and of fire. Therefore, it is not only
without the earthy and watery elements, but when fire, expelling the air
from it by the operation and force of heat, penetrates into its inmost
parts and occupies the empty spaces of the fissures, there comes a great
glow and the stone is made to burn as fiercely as do the particles of fire
itself.
3. There are also several quarries called Anician in the territory of
Tarquinii, the stone being of the color of peperino. The principal workshops
lie round the lake of Bolsena and in the prefecture of Statonia. This stone
has innumerable good qualities. Neither the season of frost nor exposure
to fire can harm it, but it remains solid and lasts to a great age, because
there is only a little air and fire in its natural composition, a moderate
amount of moisture, and a great deal of the earthy. Hence its structure
is of close texture and solid, and so it cannot be injured by the weather
or by the force of fire.
4. This may best be seen from monuments in the neighborhood of the town
of Ferento which are made of stone from these quarries. Among them are
large statues exceedingly well made, images of smaller size, and flowers
and acanthus leaves gracefully carved. Old as these are, they look as fresh
as if they were only just finished. Bronze workers, also, make molds for
the casting of bronze out of stone from these quarries, and find it very
useful in bronze founding. If the quarries were only near Rome, all our
buildings might well be constructed from the products of these workshops.
5. But since, on account of the proximity of the stone quarries of Grotta
Rossa, Palla, and the others that are nearest to the city, necessity drives
us to make use of their products, we must proceed as follows, if we wish
our work to be finished without flaws. Let the stone be taken from the
quarry two years before building is to begin, and not in winter but in
summer. Then let it lie exposed in an open place. Such stone as has been
damaged by the two years of exposure should be used in the foundations.
The rest, which remains unhurt, has passed the test of nature and will
endure in those parts of the building which are above ground. This precaution
should be observed, not only with dimension stone, but also with the rubble
which is to be used in walls.
Chapter VIII
Methods of Building Walls
1. There are two styles of walls: "opus reticulatum," now used by everybody,
and the ancient style called "opus incertum." Of these, the reticulatum
looks better, but its construction makes it likely to crack, because its
beds and builds spread out in every direction. On the other hand, in the
opus incertum, the rubble, lying in courses and imbricated, makes a wall
which, though not beautiful, is stronger than the reticulatum.
2. Both kinds should be constructed of the smallest stones, so that
the walls, being thoroughly puddled with the mortar, which is made of lime
and sand, may hold together longer. Since the stones used are soft and
porous, they are apt to suck the moisture out of the mortar and so to dry
it up. But when there is abundance of lime and sand, the wall, containing
more moisture, will not soon lose its strength, for they will hold it together.
But as soon as the moisture is sucked out of the mortar by the porous rubble,
and the lime and sand separate and disunite, the rubble can no longer adhere
to them and the wall will in time become a ruin.
3. This we may learn from several monuments in the environs of the city,
which are built of marble or dimension stone, but on the inside packed
with masonry between the outer walls. In the course of time, the mortar
has lost its strength, which has been sucked out of it by the porousness
of the rubble; and so the monuments are tumbling down and going to pieces,
with their joints loosened by the settling of the material that bound them
together.
4. He who wishes to avoid such a disaster should leave a cavity behind
the facings, and on the inside build walls two feet thick, made of red
dimension stone or burnt brick or lava in courses, 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 also used. 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, by their bonding powers they add very greatly
to the solidity of the walls.
8. One who in accordance with these notes will take pains in selecting
his method of construction, may count upon having something that will last.
No walls made of rubble and finished with delicate beauty no such walls
can escape ruin as time goes on. Hence, when arbitrators are chosen to
set a valuation on party walls, they do not value them at what they cost
to build, but look up the written contract in each case and then, after
deducting from the cost one eightieth for each year that the wall has been
standing, decide that the remainder is the sum to be paid. They thus in
effect pronounce that such walls cannot last more than eighty years.
9. In the case of brick walls, however, no deduction is made provided
that they are still standing plumb, but they are always valued at what
they cost to build. Hence in some states we may see public buildings and
private houses, as well as those of kings, built of brick: in Athens, for
example, the part of the wall which faces Mt. Hymettus and Pentelicus;
at Patras, the cellae of the temple of Jupiter and Hercules, which are
brick, although on the outside the entablature and columns of the temple
are of stone; in Italy, at Arezzo, an ancient wall excellently built; at
Tralles, the house built for the kings of the dynasty of Attalus, which
is now always granted to the man who holds the state priesthood. In Sparta,
paintings have been taken out of certain walls by cutting through the bricks,
then have been placed in wooden frames, and so brought to the Comitium
to adorn the aedileship of Varro and Murena.
10. Then there is the house of Croesus which the people of Sardis have
set apart as a place of repose for their fellow citizens in the retirement
of age, a "Gerousia" for the guild of the elder men. At Halicarnassus,
the house of that most potent king Mausolus, though decorated throughout
with Proconnesian marble, has walls built of brick which are to this day
of extraordinary strength, and are covered with stucco so highly polished
that they seem to be as glistening as glass. That king did not use brick
from poverty; for he was chockfull of revenues, being ruler of all Caria.
11. As for his skill and ingenuity as a builder, they may be seen from
what follows. He was born at Melassa, but recognizing the natural advantages
of Halicarnassus as a fortress, and seeing that it was suitable as a trading
center and that it had a good harbor, he fixed his residence there. The
place had a curvature like that of the seats in a theater. On the lowest
tier, along the harbor, was built the forum. About halfway up the curving
slope, at the point where the curved cross aisle is in a theater, a broad
wide street was laid out, in the middle of which was built the Mausoleum,
a work so remarkable that it is classed among the Seven Wonders of the
World. At the top of the hill, in the center, is the fane of Mars, containing
a colossal acrolithic statue by the famous hand of Leochares. That is,
some think that this statue is by Leochares, others by Timotheus. At the
extreme right of the summit is the fane of Venus and Mercury, close to
the spring of Salmacis.
12. There is a mistaken idea that this spring infects those who drink
of it with an unnatural lewdness. It will not be out of place to explain
how this idea came to spread throughout the world from a mistake in the
telling of the tale. It cannot be that the water makes men effeminate and
unchaste, as it is said to do; for the spring is of remarkable clearness
and excellent in flavor. The fact is that when Melas and Arevanias came
there from Argos and Troezen and founded a colony together, they drove
out the Carians and Lelegans who were barbarians. These took refuge in
the mountains, and, uniting there, used to make raids, plundering the Greeks
and laying their country waste in a cruel manner. Later, one of the colonists,
to make money, set up a well stocked shop, near the spring because the
water was so good, and the way in which he carried it on attracted the
barbarians. So they began to come down, one at a time, and to meet with
society, and thus they were brought back of their own accord, giving up
their rough and savage ways for the delights of Greek customs. Hence this
water acquired its peculiar reputation, not because it really induced unchastity,
but because those barbarians were softened by the charm of civilization.
13. But since I have been tempted into giving a description of this
fortified place, it remains to finish my account of it. Corresponding to
the fane of Venus and the spring described above, which are on the right,
we have on the extreme left the royal palace which king Mausolus built
there in accordance with a plan all his own. To the right it commands a
view of the forum, the harbor, and the entire line of fortifications, while
just below it, to the left, there is a concealed harbor, hidden under the
walls in such a way that nobody could see or know what was going on in
it. Only the king himself could, in case of need, give orders from his
own palace to the oarsmen and soldiers, without the knowledge of anybody
else.
14. After the death of Mausolus, his wife Artemisia became queen, and
the Rhodians, regarding it as an outrage that a woman should be ruler of
the states of all Caria, fitted out a fleet and sallied forth to seize
upon the kingdom. When news of this reached Artemisia, she gave orders
that her fleet should be hidden away in that harbor with oarsmen and marines
mustered and concealed, but that the rest of the citizens should take their
places on the city wall. After the Rhodians had landed at the larger harbor
with their well equipped fleet, she ordered the people on the wall to cheer
them and to promise that they would deliver up the town. Then, when they
had passed inside the wall, leaving their fleet empty, Artemisia suddenly
made a canal which led to the sea, brought her fleet thus out of the smaller
harbor, and so sailed into the larger. Disembarking her soldiers, she towed
the empty fleet of the Rhodians out to sea. So the Rhodians were surrounded
without means of retreat, and were slain in the very forum.
15. So Artemisia embarked her own soldiers and oarsmen in the ships
of the Rhodians and set forth for Rhodes. The Rhodians, beholding their
own ships approaching wreathed with laurel, supposed that their fellow
citizens were returning victorious, and admitted the enemy. Then Artemisia,
after taking Rhodes and killing its leading men, put up in the city of
Rhodes a trophy of her victory, including two bronze statues, one representing
the state of the Rhodians, the other herself. Herself she fashioned in
the act of branding the state of the Rhodians. In later times the Rhodians,
laboring under the religious scruple which makes it a sin to remove trophies
once they are dedicated, constructed a building to surround the place,
and thus by the erection of the "Grecian Station" covered it so that nobody
could see it.
16. Since such very powerful kings have not disdained walls built of
brick, although with their revenues and from booty they might often have
had them not only of masonry or dimension stone but even of marble, I think
that one ought not to reject buildings made of brick-work, provided that
they are properly "topped." But I shall explain why this kind of structure
should not be used by the Roman people within the city, not omitting the
reasons and the grounds for them.
17. The laws of the state forbid that walls abutting on public property
should be more than a foot and a half thick. The other walls are built
of the same thickness in order to save space. Now brick walls, unless two
or three bricks thick, cannot support more than one story; certainly not
if they are only a foot and a half in thickness. But with the present importance
of the city and the unlimited numbers of its population, it is necessary
to increase the number of dwelling places indefinitely. Consequently, as
the ground floors could not admit of so great a number living in the city,
the nature of the case has made it necessary to find relief by making the
buildings high. In these tall piles reared with piers of stone, walls of
burnt brick, and partitions of rubble work, and provided with floor after
floor, the upper stories can be partitioned off into rooms to very great
advantage. The accommodations within the city walls being thus multiplied
as a result of the many floors high in the air, the Roman people easily
find excellent places in which to live.
18. It has now been explained how limitations of building space necessarily
forbid the employment of brick walls within the city. When it becomes necessary
to use them outside the city, they should be constructed as follows in
order to be perfect and durable. On the top of the wall lay a structure
of burnt brick, about a foot and a half in height, under the tiles and
projecting like a coping. Thus the defects usual in these walls can be
avoided. For when the tiles on the roof are broken or thrown down by the
wind so that rainwater can leak through, this burnt brick coating will
prevent the crude brick from being damaged, and the cornice like projection
will throw off the drops beyond the vertical face, and thus the walls,
though of crude brick structure, will be preserved intact.
19. With regard to burnt brick, nobody can tell 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 vigor 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 born; hence,
pregnant slaves, when offered for sale, are not warranted sound, because
the fetus as it grows within the body takes to itself as nourishment all
the best qualities of the mother's food, and so the stronger it becomes
as the full time for birth approaches, the less compact it allows that
body to be from which it is produced. After the birth of the child, what
was heretofore taken to promote the growth of another creature is now set
free by the delivery of the newborn, and the channels being now empty and
open, the body will take it in by lapping up its juices, and thus becomes
compact and returns to the natural strength which it had before.
2. On the same principle, with the ripening of the fruits in Autumn
the leaves begin to wither and the trees, taking up their sap from the
earth through the roots, recover themselves and are restored to their former
solid texture. But the strong air of winter compresses and solidifies them
during the time above mentioned. Consequently, if the timber is felled
on the principle and at the time above mentioned, it will be felled at
the proper season.
3. In felling a tree we should cut into the trunk of it to the very
heart, and then leave it standing so that the sap may drain out drop by
drop throughout the whole of it. In this way the useless liquid which is
within will run out through the sapwood instead of having to die in a mass
of decay, thus spoiling the quality of the timber. Then and not till then,
the tree being drained dry and the sap no longer dripping, let it be felled
and it will be in the highest state of usefulness.
4. That this is so may be seen in the case of fruit trees. When these
are tapped at the base and pruned, each at the proper time, they pour out
from the heart through the tapholes all the superfluous and corrupting
fluid which they contain, and thus the draining process makes them durable.
But when the juices of trees have no means of escape, they clot and rot
in them, making the trees hollow and good for nothing. Therefore, if the
draining process does not exhaust them while they are still alive, there
is no doubt that, if the same principle is followed in felling them for
timber, they will last a long time and be very useful in buildings.
5. Trees vary and are unlike one another in their qualities. Thus it
is with the oak, elm, poplar, cypress, fir, and the others which are most
suitable to use in buildings. The oak, for instance, has not the efficacy
of the fir, nor the cypress that of the elm. Nor in the case of other trees,
is it natural that they should be alike; but the individual kinds are effective
in building, some in one way, some in another, owing to the different properties
of their elements.
6. To begin with fir: it contains a great deal of air and fire with
very little moisture and the earthy, so that, as its natural properties
are of the lighter class, it is not heavy. Hence, its consistence being
naturally stiff, it does not easily bend under the load, and keeps its
straightness when used in the framework. But it contains so much heat that
it generates and encourages decay, which spoils it; and it also kindles
fire quickly because of the air in its body, which is so open that it takes
in fire and so gives out a great flame.
7. The part which is nearest to the earth before the tree is cut down
takes up moisture through the roots from the immediate neighborhood and
hence is without knots and is "clear." But the upper part, on account of
the great heat in it, throws up branches into the air through the knots;
and this, when it is cut off about twenty feet from the ground and then
hewn, is called "knotwood" because of its hardness and knottiness. The
lowest part, after the tree is cut down and the sapwood of the same thrown
away, is split up into four pieces and prepared for joiner's work, and
so is called "clearstock."
8. Oak, on the other hand, having enough and to spare of the earthy
among its elements, and containing but little moisture, air, and fire,
lasts for an unlimited period when buried in underground structures. It
follows that when exposed to moisture, as its texture is not loose and
porous, it cannot take in liquid on account of its compactness, but, withdrawing
from the moisture, it resists it and warps, thus making cracks in the structures
in which it is used.
9. The winter oak, being composed of a moderate amount of all the elements,
is very useful in buildings, but when in a moist place, it takes in water
to its center through its pores, its air and fire being expelled by the
influence of the moisture, and so it rots. The Turkey oak and the beech,
both containing a mixture of moisture, fire, and the earthy, with a great
deal of air, through this loose texture take in moisture to their center
and soon decay. White and black poplar, as well as willow, linden, and
the agnus castus, containing an abundance of fire and air, a moderate amount
of moisture, and only a small amount of the earthy, are composed of a mixture
which is proportionately rather light, and so they are of great service
from their stiffness. Although on account of the mixture of the earthy
in them they are not hard, yet their loose texture makes them gleaming
white, and they are a convenient material to use in carving.
10. The alder, which is produced close by river banks, and which seems
to be altogether useless as building material, has really excellent qualities.
It is composed of a very large proportion of air and fire, not much of
the earthy, and only a little moisture. Hence, in swampy places, alder
piles driven close together beneath the foundations of buildings take in
the water which their own consistence lacks and remain imperishable forever,
supporting structures of enormous weight and keeping them from decay. Thus
a material which cannot last even a little while above ground, endures
for a long time when covered with moisture.
11. One can see this at its best in Ravenna; for there all the buildings,
both public and private, have piles of this sort beneath their foundations.
The elm and the ash contain a very great amount of moisture, a minimum
of air and fire, and a moderate mixture of the earthy in their composition.
When put in shape for use in buildings they are tough and, having no stiffness
on account of the weight of moisture in them, soon bend. But when they
become dry with age, or are allowed to lose their sap and die standing
in the open, they get harder, and from their toughness supply a strong
material for dowels to be used in joints and other articulations.
12. The hornbeam, which has a very small amount of fire and of the earthy
in its composition, but a very great proportion of air and moisture, is
not a wood that breaks easily, and is very convenient to handle. Hence,
the Greeks call it "zygia," because they make of it yokes for their draught
animals. Cypress and pine are also just as admirable; for although they
contain an abundance of moisture mixed with an equivalent composed of all
the other elements, and so are apt to warp when used in buildings on account
of this superfluity of moisture, yet they can be kept to a great age without
rotting, because the liquid contained within their substances has a bitter
taste which by its pungency prevents the entrance of decay or of those
little creatures which are destructive. Hence, buildings made of these
kinds of wood last for an unending period of time.
13. The cedar and the juniper tree have the same uses and good qualities,
but, while the cypress and pine yield resin, from the cedar is produced
an oil called cedar oil. Books as well as other things smeared with this
are not hurt by worms or decay. The foliage of this tree is like that of
the cypress but the grain of the wood is straight. The statue of Diana
in the temple at Ephesus is made of it, and so are the coffered ceilings
both there and in all other famous fanes, because that wood is everlasting.
The tree grows chiefly in Crete, Africa, and in some districts of Syria.
14. The larch, known only to the people of the towns on the banks of
the river Po and the shores of the Adriatic, is not only preserved from
decay and the worm by the great bitterness of its sap, but also it cannot
be kindled with fire nor ignite of itself, unless like stone in a lime
kiln it is burned with other wood. And even then it does not take fire
nor produce burning coals, but after a long time it slowly consumes away.
This is because there is a very small proportion of the elements of fire
and air in its composition, which is a dense and solid mass of moisture
and the earthy, so that it has no open pores through which fire can find
its way; but it repels the force of fire and does not let itself be harmed
by it quickly. Further, its weight will not let it float in water, so that
when transported it is loaded on shipboard or on rafts made of fir.
15. It is worth while to know how this wood was discovered. The divine
Caesar, being with his army in the neighborhood of the Alps, and having
ordered the towns to furnish supplies, the inhabitants of a fortified stronghold
there, called Larignum, trusting in the natural strength of their defenses,
refused to obey his command. So the general ordered his forces to the assault.
In front of the gate of this stronghold there was a tower, made of beams
of this wood laid in alternating directions at right angles to each other,
like a funeral pyre, and built high, so that they could drive off an attacking
party by throwing stakes and stones from the top. When it was observed
that they had no other missiles than stakes, and that these could not be
hurled very far from the wall on account of the weight, orders were given
to approach and to throw bundles of brushwood and lighted torches at this
outwork. These the soldiers soon got together.
16. The flames soon kindled the brushwood which lay about that wooden
structure and, rising towards heaven, made everybody think that the whole
pile had fallen. But when the fire had burned itself out and subsided,
and the tower appeared to view entirely uninjured, Caesar in amazement
gave orders that they should be surrounded with a palisade, built beyond
the range of missiles. So the townspeople were frightened into surrendering,
and were then asked where that wood came from which was not harmed by fire.
They pointed to trees of the kind under discussion, of which there are
very great numbers in that vicinity. And so, as that stronghold was called
Larignum, the wood was called larch. It is transported by way of the Po
to Ravenna, and is to be had in Fano, Pesaro, Ancona, and the other towns
in that neighborhood. If there were only a ready method of carrying this
material to Rome, it would be of the greatest use in buildings; if not
for general purposes, yet at least if the boards used in the eaves running
round blocks of houses were made of it, the buildings would be free from
the danger of fire spreading across to them, because such boards can neither
take fire from flames or from burning coals, nor ignite spontaneously.
17. The leaves of these trees are like those of the pine; timber from
them comes in long lengths, is as easily wrought in joiner's work as is
the cleared of fir, and contains a liquid resin, of the color of Attic
honey, which is good for consumptives.
With regard to the different kinds of timber, I have now explained of
what natural properties they appear to be composed, and how they were produced.
It remains to consider the question why the highland fir, as it is called
in Rome, is inferior, while the lowland fir is extremely useful in buildings
so far as durability is concerned; and further to explain how it is that
their bad or good qualities seem to be due to the peculiarities of their
neighborhood, so that this subject may be clearer to those who examine
it.
CHAPTER X
Highland and Lowland Fir
1. The first spurs of the Apennines arise from the Tuscan sea between the
Alps and the most distant borders of Tuscany. The mountain range itself
bends round and, almost touching the shores of the Adriatic in the middle
of the curve, completes its circuit by extending to the strait on the other
shore. Hence, this side of the curve, sloping towards the districts of
Tuscany and Campania, lies basking in the sun, being constantly exposed
to the full force of its rays all day. But the further side, sloping towards
the Upper Sea and having a northern exposure, is constantly shrouded in
shadowy darkness. Hence the trees which grow on that side, being nourished
by the moisture, not only themselves attain to a very large size, but their
fiber too, filled full of moisture, is swollen and distended with abundance
of liquid. When they lose their vitality after being felled and hewn, the
fiber retains its stiffness, and the trees as they dry become hollow and
frail on account of their porosity, and hence cannot last when used in
buildings.
2. But trees which grow in places facing the course of the sun are not
of porous fiber but are solid, being drained by the dryness; for the sun
absorbs moisture and draws it out of trees as well as out of the earth.
The trees in sunny neighborhoods, therefore, being solidified by the compact
texture of their fiber, and not being porous from moisture, are very useful,
so far as durability goes, when they are hewn into timber. Hence the lowland
firs, being conveyed from sunny places, are better than those highland
firs, which are brought here from shady places.
3. To the best of my mature consideration, I have now treated the materials
which are necessary in the construction of buildings, the proportionate
amount of the elements which are seen to be contained in their natural
composition, and the points of excellence and defects of each kind, so
that they may be not unknown to those who are engaged in building. Thus
those who can follow the directions contained in this treatise will be
better informed in advance, and able to select, among the different kinds,
those which will be of use in their works. Therefore, since the preliminaries
have been explained, the buildings themselves will be treated in the remaining
books; and first, as due order requires, I shall in the next book write
of the temples of the immortal gods and their symmetrical proportions.
How To Build Catapults >> Vitruvius
Ten Books of Architecture >> Book 2
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