Most of these buildings, while varying in size and in accordance with the character of their sites, are rectangular in plan, and enclose quadrangular courts, the different stories being marked by superposed orders and arcades. They are planned on a liberal scale, with broad proportions and with great deference to symmetry. The beauty of the plan was, in fact, one of the best features of the new style, not only in domestic, but in ecclesiastical architecture, for the arbitrary Gothic arrangements being once discarded, it became possible to combine the circle and straight line in many novel and beautiful ways, for which the older Roman buildings furnished admirable examples. The study of these plans forms one of the most important elements in an architect’s education, and their examination in these days of iron props and twelve-inch walls is fraught with much pleasure and profit. The light and brilliant creations of the early period are abundant in Northern Italy, and were models with which the French were readily impressed. The façade of the church in the Certosa of Pavia, with its elaborate detail and delicate ornament, and such buildings as the Spinelli Rezzonico and Vendramin palaces, the church of St. Zachariah, the Logetta and Library of St Mark’s of Sansovino, in Venice, and farther South the Palazzo Fava in Bologna, the Capella Pazzi attached to the older Sta. Croce in Florence, and the monument to Julius II. in Sta. Maria del Popolo in Rome are a few beautiful examples of the early treatment which has so much affinity with the works produced in France under the Valois. [Illustration: PLAN OF ST. PETER’S AS ORIGINALLY DESIGNED BY MICHAEL ANGELO.] The great Italian cathedral upon which nearly all subsequent churches were modelled was commenced upon the site of the old basilica of St. Peter’s in Rome in the year 1506, upon plans by Bramante, and occupied a century and a half in completion. After Bramante, Giocondo, Julian Sangallo, Raphael, Perruzzi, Antonio di Sangallo, Michael Angelo and Carlo Maderno each worked upon it in turn.