Sphere within a Sphere

Description

This sculpture, entitled "Sphere within Sphere" by Arnaldo Pomodoro, was donated by the artist in 1990 to the Vatican Museums, where it was installed in the Pinecone Courtyard. A complex assembly of this work by the artist himself is documented in the historical photos below, kindly provided by Dr. Micol Forti. The work is particularly striking in the architectural context of the courtyard, framed on one side by the dome of St. Peter's Basilica and the other from the monumental niche of the Pinecone. The sculpture is part of a vast production of similar spheres by Arnaldo Pomodoro and exhibited both in Italy and abroad. It is colossal and consists of a large sphere that contains a smaller one. The artist created this work by duplicating the same dimension of the golden ball topping the Dome of St. Peter’s. The "Sphere within a sphere", despite its colossal size, can self-rotate and is operated manually, thanks to a ball-bearing mechanism.It is said that it is also activated by the wind, blowing over Rome at sunset, with the strength to spin the ball and thus giving the spectator a unique play of light reflections. Arnaldo Pomodoro, who was trained as a goldsmith, has made a polished work, smooth and homogeneous in its spherical shape; but wide fissures show a glimpse of the dark and complex interior made of gears and geometric mechanisms. It is in contrast to the exterior, symbol, and metaphor for the dramatic confrontation between inside and outside, spirit and matter.

State of Preservation

The work has fortunately retained the original smooth external surface which contrasts with the rough and dark inside of the interior. Such a satisfactory state of preservation was due to the constant controls of the laboratory restorers of the Vatican Museums specialized in the Department of Conservation of Metal Objects. Also important was periodic maintenance by the Museum staff who regularly cleaned the surface of the work and applied special protective layers for conservation. Despite these controls, however, the work presented the typical degradation of monumental public outdoor sculptures, subject to pollutants, atmospheric precipitation, and temperature fluctuations as well as and dirt and smog deposits. Both outer and inner surfaces appeared marked by evident deposits of bird excrement which interrupted the continuity of the sculpture’s reflective surface. These layers of animal waste were extremely consistent, compact, and calcified. The previously applied protective film layer had become aged and crystallized, dimming the luster of the outer surface. The interior surfaces in the depth of the sculpture, rough and glossy dark, were covered by voluminous surface deposits of various kinds; bird’s nests were found as well as plant matter and growth, carried by the winds and animals. The rough inner surfaces showed formations of corrosion that were light-colored, powder-like, and unstable. The result, being extremely hygroscopic, favored the persistence of pollutants and moisture on the surface and are determinants of electrochemical corrosion. In some areas, the metal surface had completely lost its mirror-like polish and was strongly oxidized. The welding for the assembly of the interior parts showed many pieces that were perfectly smooth and uniformly repaired, with a mirrored surface. As one accessed the top of the work, and following the first operations of cleaning, a square-shaped manhole was found, closing the apex of the sphere and secured by four screws.  (The opening measures cm. 35x35; diameter of screw heads is 1 cm). The Director of Maintenance chose not to open it to inspect the interior, as its removal would have interrupted the uniformity and closure sealing of the surrounding area.

Restoration Procedures

The work began with a complete photographic service to document the work and its status of conservation as a whole and also in detail. This comprised of all the areas affected by corrosion. Graphic mapping of the conservation status was then executed on the tables based on the photographs. The restoration operations began with a preliminary cleaning of the surfaces; washing was carried out using controlled pressure washers and with soft brushes for the removal of the more substantial deposits. Samples were taken from zones that had been mechanically cleaned; these were then photographically documented. This covered various work areas. At the end of repeated washing operations, restoration work continued with the surface removal of all previous protective layers; this was done with the application of ecological hydro-washes (Eco Toverdekap) and using a wooden spatula. For those areas with a particular difficulty, metal brushes were used. This operation was particularly long and complex, both for the tenacity of the old protective layer as well as the difficult accessibility of all recessed portions of the gear mechanisms. The entire work surface was swabbed abundantly using alcohol and acetone to remove all residues of the protective layers and paint strippers. The next step in the process concerned treatment with a corrosion inhibitor, performed locally on the powdery areas of the cavities, with the application of a cysteine solution; and the process repeated until all corroded areas were covered. The work continued with polishing the surface of the spheres and “teeth” using abrasive paste mixed with RETSUL water PL 622. This is a fine abrasive with excellent polishing power. These operations were carried out manually and with the aid of electric hand sanders. During the polishing phase, each zone that had lost its mirrored surface and had become oxidized was treated with specifically planned operations. The oxidation was removed with soft steel brushes mounted on a small motor drill. These were then polished with repeated passages of finely-grained sandpaper. A polishing wax was then applied. The entire surface was again abundantly swabbed with alcohol to remove all residues of polishing compounds. The sculpture was then carefully dusted with compressed air, brushes, and vacuum cleaners, to prepare the surface for the protective film layer. The Department of Works has selected a specific final protective, to be applied by spray. The product used is Standocryl VOC-2K-Klarlack K9550 made by Standox, particularly effective for its characteristics of strength, transparency, and gloss. The product has been applied on the entire surface in three layers. To carry out this delicate process, the Director of Works has authorized a special session during two Sundays when the Museums are closed to the public. The rough and glossy dark surfaces areas were further treated with the application of a microcrystalline wax, Soter OS, applied by brush and not polished, to emphasize the difference between shiny and matt surfaces concerning the original aesthetic effect. A complete digital photographic documentation of the various phases was produced, here in the annex to this report, in CD Rom. In addition, graphic documentation for mapping the entire state of conservation and techniques has been also been produced.