 Giacomo della Porta subsequently altered this model in several ways.The major change restored an earlier design, in which the outer dome appears to rise above, rather than rest directly on the base.Most of the other changes were of a cosmetic nature, such as the adding of lion's masks over the swags on the drum in honour of Pope Sixtus and adding a circlet of finials around the spire at the top of the lantern, as proposed by Sangallo.