forty feet, let columns be placed
inside and opposite to the columns between the antae. They should have
the same height as the columns in front of them, but their thickness
should be proportionately reduced: thus, if the columns in front are in
thickness one eighth of their height, these should be one tenth; if the
former are one ninth or one tenth, these should be reduced in the same
proportion. For their reduction will not be discernible, as the air has
not free play about them. Still, in case they look too slender, when the
outer columns have twenty or twenty-four flutes, these may have
twenty-eight or thirty-two. Thus the additional number of flutes will
make up proportionately for the loss in the body of the shaft,
preventing it from being seen, and so in a different way the columns
will be made to look equally thick.

[Illustration: VITRUVIUS' TEMPLE PLAN COMPARED WITH ACTUAL EXAMPLES]

3. The reason for this result is that the eye, touching thus upon a
greater number of points, set closer together, has a larger compass to
cover with its range of vision. For if two columns, equally thick but
one unfluted and the other fluted, are measured by drawing lines round
them, one line touching the body of the columns in the hollows of the
channels and on the edges of the flutes, these surrounding lines, even
though the columns are equally thick, will not be equal to each other,
because it takes a line of greater length to compass the channels and
the flutes. This being granted, it is not improper, in narrow quarters
or where the space is enclosed, to use in a building columns of somewhat
slender proportions, since we can help out by a duly proportionate
number of flutings.

4. The walls of the cella itself should be thick in proportion to its
size, provided that their antae are kept of the same thickness as the
columns. If the walls are to be of masonry, let the rubble used be as
small as possible; but if they are to be of dimension stone or marble,
the material ought to be of a very moderate and uniform size; for the
laying of the stones so as to break joints will make the whole work
stronger, and their bevelled edges, standing up about the builds and
beds, will give it an agreeable look, somewhat like that of a picture.

CHAPTER V

HOW THE TEMPLE SHOULD FACE

1. The quarter toward which temples of the immortal gods ought to face
is to be determined on the principle that, if there is no reason to
hinder an