Meanwhile a difference of opinion had arisen as to whether the plan should be a Greek or Latin cross. The construction was continued under the directorship of Sangallo the Younger and Peruzzi, until in 1546 Michelangelo was appealed to. He rescued the ground plan of Bramante, reinforced the piers which the latter had begun at the crossing, and made drawings and a wooden model of the dome as far up as the lantern and actually completed the erection of the drum. He was succeeded by Vignola, who added the four cupolas around the dome. The dome itself was completed from Michelangelo’s model, and finished (1585-1590) with a lantern, by Giacomo della Porta and Fontana. During 1605-1612, at the instance of Paul V, the nave was lengthened by Carlo Maderna to form a Latin instead of a Greek cross and the façade was erected. Finally, between 1629 and 1667, Bernini constructed the brazen baldachino and lavished sculpture on the interior, while completing the exterior effect by the colonnades which enclose the Piazza. Easily the largest church in the world, S. Peter’s compares with other large churches as follows, the figures representing square yards of area in round numbers: =S. Peter’s=, 18,000; =Seville=, 13,000; =Milan=, 10,000; =S. Paul’s=, =London=, 9000; =S. Sophia=, 8000; =Cologne=, 7000. The interior measurement of S. Peter’s is approximately 205 yards long; the nave being 150 feet high and 87 feet wide (the same dimensions as those of the great hall of the Constantine basilica). The dome from the pavement to the summit of the lantern is 403 feet, the cross adding another 30; while the diameter is 138 feet, about five feet less than the dome of the Pantheon. The prolongation of the nave by three bays has destroyed the symmetry of mass, conceived by Bramante and Michelangelo, besides interfering with the exterior view of the dome, which is visible only from a distance. The east façade (for S. Peter’s reverses the usual orientation from west to east) is, for all its magnitude, unimpressive. Its extension beyond the actual edifice at each end still further accentuates the comparatively mean scale of the portal. But scale is very generally sacrificed both on the exterior and in the interior of S. Peter’s. This is attributed by experts to the change of design introduced by Michelangelo.