Technical-scientific investigations to detect the temporal vicissitudes of the funeral monument of Innocent VIII (Giovanbattista Cibo, 1484–1492), compared with that of Sixtus IV (Francesco della Rovere 1471–1484), both made by Antonio del Pollaiolo

Abstract

The restoration of the funeral monument of Innocent VIII (Giovan-Battista Cibo, 1484–1492) was executed by Sante Guido with the support of the Knights of Columbus. The praiseworthy intervention aimed at restoring the monument from polluting aerodynamic agents has at the same time enabled a careful study of the work regarding, above all, the authenticity of the current coloring in relation to the original presentation intended by Antonio del Pollaiolo. In particular, an attempt has been made to uncover the historical vicissitudes of the work: from its realization to the present restoration. In this regard, I would like to recall that, as reported by Pasquale Rotondi, the restoration of a work is a very special moment in which it is possible to carry out all the studies aimed at understanding the causes which have determined its state of conservation, as well as, of course, its constituent elements and its implementing methods.

Keywords:

• Restoration
• Pollaiolo
• colors
• pigments
• cultural heritage

Acknowledgments

I would like to thank Cardinal Angelo Comastri, President of the Fabbrica di San Pietro and His Eminence, Mgr Vittorio Lanzani, Delegate of the same Fabbrica, for having shared the need to disclose with this article the scientific information regarding Pollaiolo’s bronze works of art conserved in St. Peter’s Basilica in the Vatican. The restoration work, conducted by Dr. Sante Guido between 2010 and 2011, was carried out by the Fabbrica di San Pietro with the scientific direction of the work by Dr. Pietro Zander and with the technical scientific advice of the present writer.

The investigations on the funeral monument of Pope Innocent VIII were carried out by:

Stefano Ridolfi – Ars-Mensurae – Analysis by XRF to identify the percentage of alloy elements.

Mirella Baldan – R & C – Analysis and Applied Research Laboratory – Physical and chemical analysis carried out with XRD, EDS, FT-IR and CG-MS to detect degradation status of bronze, the authenticity of green coloring and of the gilding, the substances attached to the work to protect it from external atmospheric pollutants.

Daniela Ferro – University of Rome La Sapienza – SEM-EDS investigations to detect the distribution of alloy elements.

Laura Cartechini, Costanza Miliani of the Institute of Molecular Sciences and Technologies U.O. of Perugia and Alessia Daveri, Manuela Vagnini of the Diagnostic Laboratory for Cultural Heritage of Spoleto, analysis with XRF and FT-IR with the Fourier convertor aimed at identifying the application of gilding and any differences between them.

Mallio Falcioni – Photographic documentation and computerized processing.