be set against the attic of the drum, and carried up against the dome itself; and again it was proposed that massive abutments be built up over each of the four great piers, but to this it was objected that the additional weight of such abutments would dangerously overcharge the substructure. The most radical suggestion was that both dome and drum be demolished and rebuilt in a more pointed form. All of these suggestions were rejected, and it was finally decided to employ the additional chains proposed by Poleni as already stated. The dome of St. Peter’s (Plate III) was conceived in a grandiose spirit, which, while it drew inspiration in part from the ancient Roman source, recklessly disregarded the lessons which Roman art should teach as to principles of construction. I have said that Brunelleschi led the way in a wrong direction when he set his great dome on the top of its drum, and had resort to clamps and chains for the resistance to its thrusts that should have been given by abutment. In following his example, Michael Angelo wandered still farther from the path of true and monumental art. To make a dome on a large scale a conspicuous object, from the springing to the crown, is a thing that cannot be safely done in stone masonry. To make it stand at all, resort must be had to extraneous and hidden means of support, and even these are of uncertain efficiency for any length of time. The ancient Roman and the Byzantine builders settled, I think, for all time the proper mode of constructing domed edifices. Bramante had recognized this, and while striving to include in his design for the dome of St. Peter’s as much as he could of the new character embodied in Brunelleschi’s dome, he tried at the same time to keep safely within the limits of the principles that had governed the ancient practice. He gave as much elevation to his dome as he thought these principles would allow, but even this, as we have seen, was too much, and in greatly increasing this elevation, so as to leave the dome entirely without abutment, Michael Angelo took unwarrantable risks, and lent his genius to the support of false principles. That this has not been generally recognized is due to the fact, already remarked, that the architects and leaders of taste of the Renaissance have made too little account of structural propriety, and structural expression, as a necessary basis for architectural design.