Vasari does not say that the art of working the stone was ever wholly lost, and mentions, ante, p. [29], the cutting of the stone for use in inlaid pavements, Cosmati-work, and the like, as may be seen in St. Mark’s, Venice; at Ravello, and in numberless Roman churches. He also describes the ‘scabbling’ of the stone by heavy hammers with steel points to reduce it to even surfaces both rounded and flat (ante, p. [31]). Fine examples of the use of the material in mediaeval days, for purposes other than statuesque, can be seen in the Cathedral of Palermo. There are there four noble sarcophagi, with canopies supported by monolithic shafts all in the same stone, dating from the thirteenth century. They contain the bodies of the Emperor Frederick II, who died in 1250, and of earlier members of his house, and show that at that time the artificers of southern Italy and Sicily could deal successfully on a large scale with this intractable material. Anton Springer, die Mittelalterliche Kunst in Palermo, Bonn, 1869, remarks in this connection, p. 29, that the Sicilians are to this day specially expert in the working of hard stones. Porphyry was also used on the original façade of S. Maria del Fiore at Florence that was demolished in 1588. Vasari might too have mentioned the porphyry sarcophagus completed in 1472 by Andrea del Verrocchio for the monument of Piero and Giovanni de’ Medici in S. Lorenzo at Florence. The Verrocchio sarcophagus is however composed only of flat slabs of porphyry, like those round the pulpit in St. Mark’s, Venice, whereas Vasari is drawing a distinction between this architectural use of the stone and its employment in figure sculpture, of which he makes Francesco del Tadda the first restorer.
In regard to this use of porphyry it must not be forgotten that in the Cabinet of Gems in the Uffizi there is a beautifully executed porphyry statuette, or rather group, of Venus with Cupid, about ten inches high, signed in Greek characters with the name of ‘Pietro Maria.’ This was Pier Maria da Pescia, noticed by Vasari in his life of Valerio Vicentino and others, as a famous worker in hard stones of the days of Leo X (Opere, V, 370). This however was executed, so Zobi says (p. 97), with the wheel after the manner of gem engraving, whereas the works of Ferrucci, of later date, were on the scale of statuary proper.
In connection with the latter we have Vasari’s story of the invention of Duke Cosimo. This is explained by Galluzzi, (Istoria del Granducato di Toscana, Firenze, 1781, I, 157 f.) who says that Cosimo’s efforts to exploit the mineral wealth of Tuscany (see postea, p. 120 f.) gave him an interest in metals, and that he set up a laboratory in his palace, where he carried on experiments in chemistry and physics. Hence the discovery of which Vasari writes. Cosimo certainly in his own time had some personal association with this cutting of porphyry, for Galluzzi says he used to make presents to his friends of porphyry reliefs executed with tools tempered by the new process, and quotes (II, 229) a letter of thanks from a Cardinal to whom a gift of the kind had been forwarded. On the other hand Cellini, (Scultura, ch. 6) makes Tadda the inventor and ignores Cosimo altogether, while Baldinucci, though, like Vasari, he was devoted to the Medici, scouts the idea of Cosimo having had any personal share in the invention of the new tempering bath, which he ascribes to Tadda alone, and he adduces in support of this Tadda’s own testament, in which are the words Franciscus de Fesulis sculptor porfidi, et ipse inventor, seu renovator talis sculpturae, et artis porfidorum incidendi. Cosimo’s participation in the discovery, whatever it was, can hardly have been ascribed to him without some small foundation in fact, and Aurelio Gotti, Le Gallerie e I Musei di Firenze, 2nd Ed., Firenze, 1875, p. 45, gives credit for it to the Duke.
However this may be, Tadda appears to have used the new process for the first time in the production of the tazza for the fountain in the cortile of the Palazzo Vecchio, and to have advanced from this to the more artistic work Vasari goes on to describe. Endeavours to discover the present habitat of the oval portraits of the Medici and the Head of Christ, referred to by Vasari, ante, p. [33], have led to the following result. Signor Supino, the Director of the National Museum at Florence, courteously informed us that the portraits of Cosimo Pater Patriae, of Leo X, and of Clement VII, with one of Giovanni de’ Bicci, were preserved in the magazines of the Bargello, where he has kindly allowed one of us to photograph them. The head of Cosimo has on the chamfer of the bust the inscription OPA DI FRANCO DA FIESOLE, which identifies it with certainty as the work of Tadda of which Vasari writes. The others are treated in the same fashion, and all are mounted on flat oval slabs of green serpentine of Prato. They are no doubt all by the same hand. They were formerly in the Uffizi but have been for many years in the Bargello, and their historical and artistic interest would certainly vindicate for them more honourable treatment than at present is their lot. Plates III and V give the Cosimo Pater Patriae portrait and that of Leo X. They measure about 19 in. by 14 in.
With regard to the other examples noticed by Vasari, Zobi, l.c., p. 108, informed his readers that the two ovals of Duke Cosimo I and his wife the Duchess Leonora were at that time (about 1850) in the Pitti ‘on the wall of the vestibule in the part called Meridiana,’ but he complicates matters by announcing the same about the head of the older Cosimo, which we have just found at the Bargello, and which Gotti says, l.c., p. 46, was originally in the Villa of Poggio Imperiale whence it was conveyed in 1862 to the Uffizi. Zobi’s words are subjoined in the original. ‘Ed i ritratti in profilo del duca Cosimo I, d’ Eleonora di Toledo sua moglie, e di Cosimo appellato il padre della patria, scolpiti a mezzo rilievo e rapportati sul fondo di serpentino, si trovano oggidì situati insieme con altri ritratti parimente porfiretici, sulle pareti del vestibolo al quartiere detto della Meridiana nel palazzo regale.’
The part of the Pitti referred to is on the second floor of the palace and receives its name from a meridian line in brass marked on the floor on which, at the psychological moment, the sun shines through a hole in the roof. Here, through the courtesy of Signor Cornish the Conservator of the Royal Palace, we have seen no fewer than seven oval portraits in porphyry mounted on serpentine that are built into the wall in situations which make their study rather difficult. Among them the marked features of Duke Cosimo are not apparent, but on one of them is the inscription, ‘Ferdinandus Magnus Dux Etr. 1609,’ and on another the name and date of Christina, Duchess of Tuscany, 1669. This all bears out what Baldinucci tells us, that the Ferrucci family in general put their hands to this particular class of work, which was their speciality, just as the glazed terra-cottas were specialities of the della Robbia, while they also adopted into the circle pupils from outside. Zobi, p. 109, quotes an old inventory of 1574, the date of the death of Duke Cosimo I, which mentions ten such portraits of members of the family as at that time existing, all mounted on serpentine. Later on, Baldinucci mentions three sons of Francesco, to one of whom, Romolo, he is supposed to have left his ‘secret.’ There was however also an Andrea Ferrucci, and a Mattias Ferrucci, who if they lacked the pretended ‘secret’ at any rate did the same work, and finally one Raffaello Curradi, a pupil of Andrea, who in 1636 abandoned sculpture and took the Franciscan habit. According to Zobi, p. 116, he was the last of the porphyry sculptors, and ‘dopo quest’ epoca affatto s’ ignora se furono prodotte altre opere porfiree.’ In view of the date 1669 on one of the ovals in the Pitti, this should not perhaps be taken too absolutely. That porphyry has been worked successfully at Florence at later dates, the admirable restoration of the porphyry tazza in the Pitti, mentioned ante, p. [109], and other more recent productions noted by Zobi, sufficiently show.
Plate V
PORTRAIT IN PORPHYRY OF LEO X
BY FRANCESCO DEL TADDA
If we add to the series of ovals the various porphyry busts of members of the Medici house, exhibited in the outer vestibule of the Uffizi and other places, there would be enough porphyry versions of the Medici to furnish material for a monograph.
With regard finally to the ‘Head of Christ’ which Vasari says was taken to Rome and much admired by Michelangelo, the original seems to be lost, but Zobi states, p. 95, that in his time a scion of the Ferrucci family, living at Lugo in the Province of Ravenna, possessed a head of Christ in porphyry signed Mathias Ferrucceus Civis Florentinus Fecit, and he thinks this may have been copied from the original by Francesco del Tadda, of which there is question in Vasari’s text.