Over the first great cornice within the tribune there begin at the foot the compartments for the recesses that are in the vault of the tribune, which are formed by sixteen projecting ribs. These at the foot are as broad as the breadth of the two pilasters which at the lower end border each window below the vault of the tribune, and they rise, diminishing pyramidally, as far as the eye of the lantern; at the foot they rest on pedestals of the same breadth and twelve palms high, and these pedestals rest on the level platform of the cornice which goes in a circle right round the tribune. Above this, in the recessed spaces between the ribs, there are eight large ovals, each twenty-nine palms high, and over them a number of straight-sided compartments that are wider at the foot and narrower at the top, and twenty-four palms high, and then, the ribs drawing together, there comes above each straight-sided compartment a round fourteen palms high; so that there come to be eight ovals, eight straight-sided compartments, and eight rounds, each range forming recesses that grow more shallow in succession. The ground of all these displays extraordinary richness, for Michelagnolo intended to make the ribs and the ornaments of the said ovals, straight-sided compartments, and rounds, all corniced in travertine.
It remains for us to make mention of the surface and adornment of the arch on that side of the vault where the roofing is to go, which begins to rise from a base twenty-five palms and a half high, which has at the foot a basement that has a projection of two palms, as have the crowning mouldings at the top. The covering or roofing with which he proposed to cover it is of lead, such as covers the roof of the old S. Pietro at the present day, and is divided into sixteen sections from one solid base to another, each base beginning where the two columns end, which are one on either side of it. In each of these sections, in the centre, he made two windows to give light to the inner space where the ascent of the stairs is, between the two shells, so that in all they are thirty-two. These, by means of brackets that support a quarter-round, he made projecting from the roof in such a manner as to protect the lofty and novel view-point from the rain. In a line with the centre of the solid base between each two columns, above which was the crowning cornice, sprang a rib, one to each, wider at the foot and narrowing at the top; in all sixteen ribs, five palms broad, in the centre of each of which was a quadrangular channel one palm and a half wide, within which is formed an ascent of steps about one palm high, by which to ascend or descend between the platform at the foot and the summit where the lantern begins. These are to be built of travertine and constructed with mortisings, to the end that the joins may be protected against water and ice during times of rain.
The design for the lantern is reduced in the same proportion as all the rest of the work, so that, taking lines round the circumference, everything comes to diminish in exact accord, and with proportionate measurements it rises as a simple temple with round columns two by two, like those on the solid bases below. These have pilasters to correspond to them, and one can walk all the way round and see from the central spaces between the pilasters, where the windows are, the interior of the tribune and the church. Above this, architrave, frieze, and cornice curve in a round, projecting over each pair of columns; and over these columns, in a line with them, spring some caulicoles, which, together with some niches that divide them, rise to find the end of the lantern, which, beginning to draw together, grows gradually narrower for a third of its height, in the manner of a round pyramid, until it reaches the ball, upon which, as the final crown of the structure, goes the cross. Many particulars and minute details I might have mentioned, such as air-holes for protection against earthquakes, water-conduits, the various lights, and other conveniences, but I omit them because the work is not yet come to completion, being content to have touched on the principal parts as well as I have been able. For, since every part is in existence and can be seen, it is enough to have made this brief sketch, which is a great light to him who has no knowledge of the structure.
The completion of this model caused the greatest satisfaction not only to all his friends, but to all Rome, the form of the fabric having been thus settled and established. It then came to pass that Paul IV died, and after him was elected Pius IV, who, while causing the building of the little palace in the wood of the Belvedere to be continued by Pirro Ligorio, who remained architect to the Palace, made many gracious offers and advances to Michelagnolo. The Motu-proprio originally received by Michelagnolo from Paul III, and then from Julius III and Paul IV, in respect of the fabric of S. Pietro, he confirmed in his favour, and he restored to him a part of the revenues and allowances taken away by Paul IV, employing him in many of his works of building; and in his time he caused the fabric of S. Pietro to be carried on vigorously. He made use of Michelagnolo, in particular, in preparing a design for the tomb of the Marchese Marignano, his brother, which, destined to be erected in the Duomo of Milan, was allotted by his Holiness to the Chevalier Leone Lioni of Arezzo, a most excellent sculptor and much the friend of Michelagnolo; the form of which tomb will be described in the proper place.
At this time the Chevalier Leone made a very lively portrait of Michelagnolo in a medal, and to please him he fashioned on the reverse a blind man led by a dog, with these letters around:
DOCEBO INIQUOS VIAS TUAS, ET IMPII AD TE CONVERTENTUR.
And Michelagnolo, since it pleased him much, presented him a model in wax of Hercules crushing Antæus, by his own hand, with certain of his designs. Of Michelagnolo we have no other portraits but two in painting, one by the hand of Bugiardini and the other by Jacopo del Conte, one in bronze executed in full-relief by Daniello Ricciarelli, and this one by the Chevalier Leone; from which portraits so many copies have been made, that I have seen a good number in many places in Italy and in foreign parts.
The same year Cardinal Giovanni de' Medici, the son of Duke Cosimo, went to Rome to receive the hat from Pius IV, and it fell to Vasari, as his servant and familiar friend, to go with him; which Vasari went there willingly and stayed about a month, in order to enjoy Michelagnolo, who received him with great affection and was always with him. Vasari had taken with him, by order of his Excellency, a model in wood of the whole Ducal Palace of Florence, together with designs of the new apartments that had been built and painted by him; which Michelagnolo desired to see both in the model and in the designs, since, being old, he was not able to see the works themselves. These works, which were abundant and well varied, with different inventions and fancies, began with the Castration of Uranus and continued in stories of Saturn, Ops, Ceres, Jove, Juno, and Hercules, each room having one of these names, with the stories in various compartments; even as the other chambers and halls, which were beneath these, had the names of the heroes of the House of Medici, beginning with the elder Cosimo, and continuing with Lorenzo, Leo X, Clement VII, Signor Giovanni, Duke Alessandro, and Duke Cosimo, in each of which were not only the stories of their actions, but also portraits of them, of their children, and of all the ancients renowned in statesmanship, in arms, and in letters, taken from the life. Of these Vasari had written a Dialogue in which he explained all the stories, the end of the whole invention, and how the fables above harmonized with the stories below; which was read to Michelagnolo by Annibale Caro, and he took the greatest pleasure in it. This Dialogue, when Vasari shall have more time, will be published.
The result of all this was as follows. Vasari was desirous of setting his hand to the Great Hall, and since, as has been said elsewhere, the ceiling was low, making it stunted and wanting in lights, he had a desire to raise that ceiling. Now the Duke would not make up his mind to give him leave that it should be raised; not that the Duke feared the cost, as was seen afterwards, but rather the danger of raising the beams of the roof thirteen braccia. However, like a man of judgment, his Excellency consented that the advice of Michelagnolo should be taken, and Michelagnolo, having seen in that model the Hall as it then was, and afterwards, all the beams having been removed and replaced by other beams with a new invention in the ceiling and walls, the same Hall as it has since been made, with the invention of the stories likewise designed therein, liked it and straightway became not a judge but a supporter, and the rather as he saw the facile method of raising the beams and the roof, and the plan for executing the whole work in a short time. Wherefore, on Vasari's return, he wrote to the Duke that he should carry out that undertaking, since it was worthy of his greatness.