The history of its building is largely a story of contentions and troubles between popes, architects, and artists of different kinds. As it now stands it is as much the work of Michael Angelo as of any one man, but several other architects left their imprint upon it, both before and after his time; and all who aided in its construction were eminent men, in their way. Michael Angelo was in his seventy-second year when he took up the task of completing St. Peter's. Bramante, Raphael, and Peruzzi had preceded him as architects of the church; Michael Angelo designed the dome, and when he was ninety it was nearly finished; the models for its completion which he made were not followed after his death; his plan would have made the church more harmonious with the dome, in size, than it now is. Money was sent in large sums, from all Europe, to carry on this work; the finest materials were used in building it, and the most gifted artists were employed in its decoration; it is now the vast home of multitudes of treasures. "I have hung the Pantheon in the air!" Michael Angelo is said to have exclaimed, while looking at the splendid dome of St. Peter's; and no dome in the world has a more imposing effect, although its harmony with the rest of the building is injured by the change of the plan from that of a Greek cross which was made after his death.[A] [A] The interior diameter of the dome of St. Peter's is one hundred and thirty-nine feet; that of St. Sophia, one hundred and fifteen feet, and that of Sta. Maria del Fiore, at Florence, one hundred and thirty-eight feet, six inches. In spite of all this the critics of architecture are never weary of pointing out the defects of St. Peter's; but to those who cannot apply to it the test of strictly scientific rules, its interior is sublime in its effect, and has few rivals--perhaps but one--in the world, and that is the great Hypostyle Hall at Karnak, of which we spoke when writing of Egyptian architecture. But even here the difference is almost too great to admit of comparison; the spirit of the two is so unlike--St. Peter's is complete and Karnak is a ruin--so, after all, it must be admitted that the interior of St. Peter's is superior to all other edifices of which we know (Fig. 104). [Illustration: FIG. 104.--SECTION OF ST. PETER'S.] From the time of the beginning of the Renaissance, about 1420, to about 1630, the architecture of Venice was going through a change, and finally reached such perfection that during the next half century the most magnificent style of architecture prevailed which has ever been known there. We mean to say that the whole effect was the grandest, for, while it is true that the edifices of that time are stately and striking in their appearance, it is equally true that their form and ornamentation are not as much in keeping with their use as they had been in older edifices.