hich the
thickness of a column and a half can be inserted: for example, the
temple of the Divine Caesar, that of Venus in Caesar's forum, and others
constructed like them. The systyle is a temple in which the thickness
of two columns can be placed in an intercolumniation, and in which the
plinths of the bases are equivalent to the distance between two plinths:
for example, the temple of Equestrian Fortune near the stone theatre,
and the others which are constructed on the same principles.

3. These two kinds have practical disadvantages. When the matrons mount
the steps for public prayer or thanksgiving, they cannot pass through
the intercolumniations with their arms about one another, but must form
single file; then again, the effect of the folding doors is thrust out
of sight by the crowding of the columns, and likewise the statues are
thrown into shadow; the narrow space interferes also with walks round
the temple.

4. The construction will be diastyle when we can insert the thickness of
three columns in an intercolumniation, as in the case of the temple of
Apollo and Diana. This arrangement involves the danger that the
architraves may break on account of the great width of the intervals.

5. In araeostyles we cannot employ stone or marble for the architraves,
but must have a series of wooden beams laid upon the columns. And
moreover, in appearance these temples are clumsy-roofed, low, broad, and
their pediments are adorned in the Tuscan fashion with statues of
terra-cotta or gilt bronze: for example, near the Circus Maximus, the
temple of Ceres and Pompey's temple of Hercules; also the temple on the
Capitol.

6. An account must now be given of the eustyle, which is the most
approved class, and is arranged on principles developed with a view to
convenience, beauty, and strength. The intervals should be made as wide
as the thickness of two columns and a quarter, but the middle
intercolumniations, one in front and the other in the rear, should be of
the thickness of three columns. Thus built, the effect of the design
will be beautiful, there will be no obstruction at the entrance, and the
walk round the cella will be dignified.

[Illustration: THE EUSTYLE TEMPLE OF VITRUVIUS COMPARED WITH THE TEMPLE
OF TEOS]

7. The rule of this arrangement may be set forth as follows. If a
tetrastyle is to be built, let the width of the front which shall have
already been determined for the temple, be divided into eleven parts