The Ten Books on Architecture
that of the Attic base, and so too its plinth; excluding the plinth, let
the rest, which will be a third part of the thickness of a column, be
divided into seven parts. Three of these parts constitute the torus at
the top, and the other four are to be divided equally, one part
constituting the upper trochilus with its astragals and overhang, the
other left for the lower trochilus. But the lower will seem to be
larger, because it will project to the edge of the plinth. The astragals
must be one eighth of the trochilus. The projection of the base will be
three sixteenths of the thickness of a column.
4. The bases being thus finished and put in place, the columns are to be
put in place: the middle columns of the front and rear porticoes
perpendicular to their own centre; the corner columns, and those which
are to extend in a line from them along the sides of the temple to the
right and left, are to be set so that their inner sides, which face
toward the cella wall, are perpendicular, but their outer sides in the
manner which I have described in speaking of their diminution. Thus, in
the design of the temple the lines will be adjusted with due regard to
the diminution.
5. The shafts of the columns having been erected, the rule for the
capitals will be as follows. If they are to be cushion-shaped, they
should be so proportioned that the abacus is in length and breadth
equivalent to the thickness of the shaft at its bottom plus one
eighteenth thereof, and the height of the capital, including the
volutes, one half of that amount. The faces of the volutes must recede
from the edge of the abacus inwards by one and a half eighteenths of
that same amount. Then, the height of the capital is to be divided into
nine and a half parts, and down along the abacus on the four sides of
the volutes, down along the fillet at the edge of the abacus, lines
called "catheti" are to be let fall. Then, of the nine and a half parts
let one and a half be reserved for the height of the abacus, and let the
other eight be used for the volutes.
6. Then let another line be drawn, beginning at a point situated at a
distance of one and a half parts toward the inside from the line
previously let fall down along the edge of the abacus. Next, let these
lines be divided in such a way as to leave four and a half parts under
the abacus; then, at the point which forms the division between the four
and a half parts and the remaining three and a half, fix the centre of
the eye, and from that centre describe a circle with a diameter equal to
one of the eight parts. This will be the size of the eye, and in it draw
a diameter on the line of the "cathetus." Then, in describing the
quadrants, let the size of each be successively less, by half the
diameter of the eye, than that which begins under the abacus, and
proceed from the eye until that same quadrant under the abacus is
reached.
7. The height of the capital is to be such that, of the nine and a half
parts, three parts are below the level of the astragal at the top of the
shaft, and the rest, omitting the abacus and the channel, belongs to
its echinus. The projection of the echinus beyond the fillet of the
abacus should be equal to the size of the eye. The projection of the
bands of the cushions should be thus obtained: place one leg of a pair
of compasses in the centre of the capital and open out the other to the
edge of the echinus; bring this leg round and it will touch the outer
edge of the bands. The axes of the volutes should not be thicker than
the size of the eye, and the volutes themselves should be channelled out
to a depth which is one twelfth of their height. These will be the
symmetrical proportions for capitals of columns twenty-five feet high
and less. For higher columns the other proportions will be the same, but
the length and breadth of the abacus will be the thickness of the lower
diameter of a column plus one ninth part thereof; thus, just as the
higher the column the less the diminution, so the projection of its
capital is proportionately increased and its breadth[2] is
correspondingly enlarged.
[Note 2: Codd. _altitudo_.]
8. With regard to the method of describing volutes, at the end of the
book a figure will be subjoined and a calculation showing how they may
be described so that their spirals may be true to the compass.
The capitals having been finished and set up in due proportion to the
columns (not exactly level on the columns, however, but with the same
measured adjustment, so that in the upper members there may be an
increase corresponding to that which was made in the stylobates), the
rule for the architraves is to be as follows. If the columns are at
least twelve feet and not more than fifteen feet high, let the height of
the architrave be equal to half the thickness of a column at the bottom.
If they are from fifteen feet to twenty, let the height of a column be
measured off into thirteen parts, and let one of these be the height of
the architrave. If they are from twenty to twenty-five feet, let this
height be divided into twelve and one half parts, and let one of them
form the height of the architrave. If they are from twenty-five feet to
thirty, let it be divided into twelve parts, and let one of them form
the height. If they are higher, the heights of the architraves are to be
worked out proportionately in the same manner from the height of the
columns.
9. For the higher that the eye has to climb, the less easily can it make
its way through the thicker and thicker mass of air. So it fails when
the height is great, its strength is sucked out of it, and it conveys to
the mind only a confused estimate of the dimensions. Hence there must
always be a corresponding increase in the symmetrical proportions of the
members, so that whether the buildings are on unusually lofty sites or
are themselves somewhat colossal, the size of the parts may seem in due
proportion. The depth of the architrave on its under side just above the
capital, is to be equivalent to the thickness of the top of the column
just under the capital, and on its uppermost side equivalent to the foot
of the shaft.
10. The cymatium of the architrave should be one seventh of the height
of the whole architrave, and its projection the same. Omitting the
cymatium, the rest of the architrave is to be divided into twelve parts,
and three of these will form the lowest fascia, four, the next, and
five, the highest fascia. The frieze, above the architrave, is one
fourth less high than the architrave, but if there are to be reliefs
upon it, it is one fourth higher than the architrave, so that the
sculptures may be more imposing. Its cymatium is one seventh of the
whole height of the frieze, and the projection of the cymatium is the
same as its height.
11. Over the frieze comes the line of dentils, made of the same height
as the middle fascia of the architrave and with a projection equal to
their height. The intersection (or in Greek [Greek: metopê]) is
apportioned so that the face of each dentil is half as wide as its
height and the cavity of each intersection two thirds of this face in
width. The cymatium here is one sixth of the whole height of this part.
The corona with its cymatium, but not including the sima, has the height
of the middle fascia of the architrave, and the total projection of the
corona and dentils should be equal to the height from the frieze to the
cymatium at the top of the corona.
And as a general rule, all projecting parts have greater beauty when
their projection is equal to their height.
12. The height of the tympanum, which is in the pediment, is to be
obtained thus: let the front of the corona, from the two ends of its
cymatium, be measured off into nine parts, and let one of these parts be
set up in the middle at the peak of the tympanum, taking care that it is
perpendicular to the entablature and the neckings of the columns. The
coronae over the tympanum are to be made of equal size with the coronae
under it, not including the simae. Above the coronae are the simae (in
Greek [Greek: epaietides]), which should be made one eighth higher than
the height of the coronae. The acroteria at the corners have the height
of the centre of the tympanum, and those in the middle are one eighth
part higher than those at the corners.
13. All the members which are to be above the capitals of the columns,
that is, architraves, friezes, coronae, tympana, gables, and acroteria,
should be inclined to the front a twelfth part of their own height, for
the reason that when we stand in front of them, if two lines are drawn
from the eye, one reaching to the bottom of the building and the other
to the top, that which reaches to the top will be the longer. Hence, as
the line of sight to the upper part is the longer, it makes that part
look as if it were leaning back. But when the members are inclined to
the front, as described above, they will seem to the beholder to be
plumb and perpendicular.
14. Each column should have twenty-four flutes, channelled out in such a
way that if a carpenter's square be placed in the hollow of a flute and
turned, the arm will touch the corners of the fillets on the right and
left, and the tip of the square may keep touching some point in the
concave surface as it moves through it. The breadth of the flutes is to
be equivalent to the enlargement in the middle of a column, which will
be found in the figure.
15. In the simae which are over the coronae on the sides of the temple,
lion's heads are to be carved and arranged at intervals thus: First one
head is marked out directly over the axis of each column, and then the
others are arranged at equal distances apart, and so that there shall be
one at the middle of every roof-tiling. Those that are over the columns
should have holes bored through them to the gutter which receives the
rainwater from the tiles, but those between them should be solid. Thus
the mass of water that falls by way of the tiles into the gutter will
not be thrown down along the intercolumniations nor drench people who
are passing through them, while the lion's heads that are over the
columns will appear to be vomiting as they discharge streams of water
from their mouths.
In this book I have written as clearly as I could on the arrangements of
Ionic temples. In the next I shall explain the proportions of Doric and
Corinthian temples.
BOOK IV
INTRODUCTION
1. I have observed, Emperor, that many in their treatises and volumes of
commentaries on architecture have not presented the subject with
well-ordered completeness, but have merely made a beginning and left, as
it were, only desultory fragments. I have therefore thought that it
would be a worthy and very useful thing to reduce the whole of this
great art to a complete and orderly form of presentation, and then in
different books to lay down and explain the required characteristics of
different departments. Hence, Caesar, in my first book I have set forth
to you the function of the architect and the things in which he ought to
be trained. In the second I have discussed the supplies of material of
which buildings are constructed. In the third, which deals with the
arrangements of temples and their variety of form, I showed the nature
and number of their classes, with the adjustments proper to each form