he introduced on the exterior Corinthian
pilasters resembling those of the interior, he greatly modified the
general aspect of the former by the removal of the projecting chapels
and the aisles round the apses. It was in his design for the dome that
Michael Angelo achieved his greatest architectural triumph, for without
tampering at all with what had already been done by Bramante, he set
upon the cylindrical drum that artist had intended to uphold a dome,
which was to be a mere reproduction of that of the Pantheon, a
magnificent structure of original design which dominates the capital,
producing an absolutely unrivalled impression of combined strength,
vastness, and symmetry, the eye being irresistibly led up from drum to
dome and from dome to lantern. From within the cathedral the effect is
scarcely less grand, a wonderful sense of space being conveyed by the
soaring vault, that seems to spring heavenwards of its own volition.

Michael Angelo died before his masterpiece was completed, but so far as
the dome was concerned his design was carried out, with certain slight
modifications, by Giacomo della Porta and Domenico Fontana.
Unfortunately, however, the rest of the great architect's scheme was
departed from and its effectiveness destroyed by additions which he
would most certainly have condemned. At the suggestion of Pope Pius IV
the facade built under Michael Angelo was pulled down and replaced by
Maderno with that still _in situ_, whilst the nave was lengthened out of
all proportion to the rest of the building.

In spite of this lamentable mistake, the general effect of the interior
is remarkably fine, and is greatly enhanced by the rich colouring of the
lavish decoration of every portion, the massive piers and vast arches
spanning them, and the vaulted coffered ceilings, all harmonising with
and supplementing each other. Moreover, the unhappy result of the
substitution of Maderno's for Michael Angelo's facade was to some extent
neutralised in 1666 by the erection under Bernini of the lofty colonnade
encircling the piazza of S. Peter in the simple and dignified Doric
style, that forms an appropriate approach to the cathedral.

In the Renaissance palaces of Rome classic details were more closely
copied than in Florence, pilasters and arcades forming, in almost every
case, the chief decorations of the exteriors. Notable examples are the
so-called Venetian Palaces, the Cancellaria designed by Bramante, the
Sacchetti