, with four large semi-circular apses. The four
angles made by the projecting arms of the cross were to be filled in
with a complex but well-ordered scheme of shrines and chapels, so that
externally the edifice would have presented the aspect of a square.
The central piers, at the point of junction between the arms of the
cross, supported a broad shallow dome, modelled upon that of the
Pantheon. Similar domes of lesser dimensions crowned the
out-buildings. He began by erecting the piers which were intended to
support the central dome; but working hastily and without due regard
to solid strength, Bramante made these piers too weak to sustain the
ponderous mass they had to carry. How he would have rectified this
error cannot be conjectured. Death cut his labours short in 1514, and
only a small portion of his work remains embedded at the present day
within the mightier masses raised beneath Buonarroti's cupola.

Leo X. commissioned Raffaello da Urbino to continue his kinsman's
work, and appointed Antonio da Sangallo to assist him in the month of
January 1517. Whether it was judged impossible to carry out Bramante's
project of the central dome, or for some other reason unknown to us,
Raffaello altered the plan so essentially as to design a basilica upon
the conventional ground-plan of such churches. He abandoned the Greek
cross, and adopted the Latin form by adding an elongated nave. The
central piers were left in their places; the three terminal apses of
the choir and transepts were strengthened, simplified, reduced to
commonplace. Bramante's ground-plan is lucid, luminous, and
exquisitely ordered in its intricacy. The true creation of a
builder-poet's brain, it illustrates Leo Battista Alberti's definition
of the charm of architecture, _tutta quella musica_, that melody and
music of a graceful edifice. We are able to understand what
Michelangelo meant when he remarked that all subsequent designers, by
departing from it, had gone wrong. Raffaello's plan, if carried out,
would have been monotonous and tame inside and out.

After the death of Raffaello in 1520, Baldassare Peruzzi was appointed
to be Sangallo's colleague. This genial architect, in whose style all
the graces were combined with dignity and strength, prepared a new
design at Leo's request. Vasari, referring to this period of Peruzzi's
life, says: "The Pope, thinking Bramante's scheme too large and not
likely to be in keeping, obtained a new model from Baldassar