Externally the composition is remarkably good in its larger features (Fig. 40). The dome, of slightly pointed outline, on a high drum, rises grandly from the substructure, and is well proportioned in relation to it. The wall surfaces are treated broadly, with no orders carried across them. They are divided into two stages, with a pediment over each façade. Super-imposed pilasters are set on the angles, and a Doric entablature, carried across the whole front, with ressauts over the lower pilasters, divides the two stages. The wall of the lower stage is entirely plain, with a severely simple rectangular portal surmounted by a pediment. The wall of the upper stage is divided into rectangular panels, as in the attic of the Pazzi chapel in Florence, the central panel being pierced with a square-headed window and framed with an order of which the capitals are Ionic and the entablature Doric. The cornice of the top story and the raking cornice of the pediment of each façade are broken into ressauts over the pilasters, and an order of Ionic pilasters, with a very high entablature broken into ressauts, surrounds the drum which supports the dome. Square detached towers are set in the reëntrant angles of the west side, only one of which was carried to completion. The completed one is in three stages, each adorned with a heavy order, Doric, Ionic, and Corinthian respectively. In these orders half-columns are coupled with angle pilasters, as in the interior, and the entablatures have ressauts on the angles over these members. An octagonal spire-like lantern, with a tall drum adorned with an order of Corinthian pilasters and surmounted by an attic, crowns the tower. Small obelisks set on the tower angles and reversed consoles against the angles of the attic give a simulation of Gothic form to the neo-classic scheme, and show the strong hold that mediæval ideas still retained upon the minds of the designers. The first of these spire-like towers of the Renaissance appears to be that of the church of Santo Spirito in Florence, which is spoken of by Milizia as the most beautiful of Italian bell towers.[75] It was designed by Baccio d’Agnolo, who, beginning as a wood carver, imbibed the new enthusiasm for the antique, and after studying the ancient monuments of Rome[76] began the practice of architecture. This campanile is thus noteworthy as the first of a large class of modern towers with spires of which Wren’s famous steeples were the ultimate outcome. The scheme is based on the mediæval campanile, the earliest form of which is the Lombard Romanesque tower. The Lombard tower is characterized by its simple rectangular outline, the walls rising sheer from the ground to the cornice, and strengthened and adorned with shallow pilaster-strips, corbelled string-courses marking the successive stories, and by small grouped openings. The tower of Santa Maria Novella in Florence is designed on this model, and the