, and let a place for folding doors be left in the middle
to afford entrance. This cella, excluding its walls and the passage
round the outside, should have a diameter equivalent to the height of a
column above the stylobate. Let the columns round the cella be arranged
in the symmetrical proportions just given.

3. The proportions of the roof in the centre should be such that the
height of the rotunda, excluding the finial, is equivalent to one half
the diameter of the whole work. The finial, excluding its pyramidal
base, should have the dimensions of the capital of a column. All the
rest must be built in the symmetrical proportions described above.

[Illustration: _From Durm_

THE CIRCULAR TEMPLE ACCORDING TO VITRUVIUS]

4. There are also other kinds of temples, constructed in the same
symmetrical proportions and yet with a different kind of plan: for
example, the temple of Castor in the district of the Circus Flaminius,
that of Vejovis between the two groves, and still more ingeniously the
temple of Diana in her sacred grove, with columns added on the right and
left at the flanks of the pronaos. Temples of this kind, like that of
Castor in the Circus, were first built in Athens on the Acropolis, and
in Attica at Sunium to Pallas Minerva. The proportions of them are not
different, but the same as usual. For the length of their cellae is
twice the width, as in other temples; but all that we regularly find in
the fronts of others is in these transferred to the sides.

5. Some take the arrangement of columns belonging to the Tuscan order
and apply it to buildings in the Corinthian and Ionic styles, and where
there are projecting antae in the pronaos, set up two columns in a line
with each of the cella walls, thus making a combination of the
principles of Tuscan and Greek buildings.

6. Others actually remove the temple walls, transferring them to the
intercolumniations, and thus, by dispensing with the space needed for a
pteroma, greatly increase the extent of the cella. So, while leaving all
the rest in the same symmetrical proportions, they appear to have
produced a new kind of plan with the new name "pseudoperipteral." These
kinds, however, vary according to the requirements of the sacrifices.
For we must not build temples according to the same rules to all gods
alike, since the performance of the sacred rites varies with the various
gods.

7. I have now set forth, as they have come down to me, all the
principl