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New Documentary Evidence for the Restoration of the Sixth-Century Wall Mosaics at the Eufrasiana in Porec

Authors: Ann Terry and Tom Muhlstein

Abstract

This study constitutes a preliminary report on new documentary evidence for the 19th century restoration of the sixth century wall mosaics at the cathedral in Porec. Colorful wall mosaics survive in the apses, triumphal arch and external facades of the basilica known as the Eufrasiana, named after its mid-sixth century founder, Bishop Eufrasius. The small, three-aisled basilica forms the heart of a well preserved episcopal ensemble situated along the shoreline of ancient Parentium (Parenzo, Porec), on the Istrian coast, today part of Croatia (Figs. 1-2). The most substantially preserved wall mosaics line the main apse and the triumphal arch (Fig. 3). The mosaics in the two smaller side apses are partially preserved (Figs. 4-5), while those on the upper east and west facades, with the exception of the window register on the latter, are fragmentary (Figs. 6-8). As is conventional in the period, subjects are set within architectural units defined by decorative bands: Christ and the apostles (triumphal arch, Figs. 9-11), medallions with female saints (intrados), an enthroned Virgin and Child, flanked by archangels, martyrs and, as identified by inscriptions, Maurus (confessor and bishop), Bishop Eufrasius, Archdeacon Claudius, and his son Eufrasius (half dome of the apse, Fig. 12), the dedicatory inscription (base of half dome), the Annunciation (Fig. 13), Visitation (Fig. 14), and standing figures of Zacharias, an archangel, and John the Baptist (piers between windows; and sides of apse), Christ crowning SS. Cosmas and Damian (north apse, Fig. 5), and Christ crowning S. Severus and Apollinarus (south apse, Fig. 4). On the exterior, only faint traces survive of the gables of the facades: Christ in Majesty (west, Fig. 8) and a scene that might have been the Transfiguration (east, Figs. 6-7). Four holy figures and seven candelabra appear on the window register of the lower west facade (Figs. 8, 15).


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New Documentary Evidence for the Restoration of the Sixth-Century Wall Mosaics at the Eufrasiana in Porec

by Ann Terry and Tom Muhlstein

This study constitutes a preliminary report on new documentary evidence for the 19th century restoration of the sixth century wall mosaics at the cathedral in Porec. Colorful wall mosaics survive in the apses, triumphal arch and external facades of the basilica known as the Eufrasiana, named after its mid-sixth century founder, Bishop Eufrasius. The small, three-aisled basilica forms the heart of a well preserved episcopal ensemble situated along the shoreline of ancient Parentium (Parenzo, Porec), on the Istrian coast, today part of Croatia (Figs. 1-2). The most substantially preserved wall mosaics line the main apse and the triumphal arch (Fig. 3). The mosaics in the two smaller side apses are partially preserved (Figs. 4-5), while those on the upper east and west facades, with the exception of the window register on the latter, are fragmentary (Figs. 6-8). As is conventional in the period, subjects are set within architectural units defined by decorative bands: Christ and the apostles (triumphal arch, Figs. 9-11), medallions with female saints (intrados), an enthroned Virgin and Child, flanked by archangels, martyrs and, as identified by inscriptions, Maurus (confessor and bishop), Bishop Eufrasius, Archdeacon Claudius, and his son Eufrasius (half dome of the apse, Fig. 12), the dedicatory inscription (base of half dome), the Annunciation (Fig. 13), Visitation (Fig. 14), and standing figures of Zacharias, an archangel, and John the Baptist (piers between windows; and sides of apse), Christ crowning SS. Cosmas and Damian (north apse, Fig. 5), and Christ crowning S. Severus and Apollinarus (south apse, Fig. 4). On the exterior, only faint traces survive of the gables of the facades: Christ in Majesty (west, Fig. 8) and a scene that might have been the Transfiguration (east, Figs. 6-7). Four holy figures and seven candelabra appear on the window register of the lower west facade (Figs. 8, 15).

The recovery of documentation pertaining to the nineteenth century restoration of these mosaics, and the conservation of the monument in general, has been very difficult. Istria's mercurial political history and the devastation of two World Wars have scattered the records and memories associated with these projects. Thus it was with great surprise and pleasure that inquiries at the Allgemeines Verwaltungsarchiv (Österreichisches Staatsarchiv), in Vienna, produced numerous documents about the works at the Cathedral in the second half of the nineteenth and the early twentieth century. The documents (Figs. 16-17) consist of communications and records--letters, reports, opinions, proposals, financial accounts, etc.--of the Central Commission for the Study and Preservation of Art and Historical Monuments (k.k. Central-Commission zur Erforschung und Erhaltung der Kunst- und historischen Denkmale, hereafter CCD), an agency which advised the Ministry for Church Affairs and Education (Ministerium für Cultus und Unterricht, herafter MCU), who had ultimate responsibility for the Eufrasiana. The members of the CCD (Mitglieder) were mostly high ranking scholars at the University of Vienna, among them the well known architect Baron Heinrich v. Ferstel, and Professor Max Dvorak, Generalconservator, prominent in the field of architectural preservation. The MCU appointed numerous corresponding members (correspondierende Mitglieder) in the field, with whom, together with the conservators (Conservatoren) in the provincial capitals, it maintained a voluminous correspondence. In the case of the Eufrasiana, the MCU acted through the governor's office (Statthalterei) in Trieste, which provided the engineers, plans, budgetary estimates and payments, and the district administration (Bezirkshauptmannschaft) in Parenzo.

Given the disruptive shifts in sovereignty in Istria (Austrian to 1918; Italian to 1945), little information about this restoration found its way into print, and the impact of nationalistic hostilities on collective memory has distorted the few facts which were preserved. Thus, one reads in recent accounts about two restorations, one of the holy figures and candelabra on the lower western facade (Fig. 15) done by "the Austrians" in 1886, considered a poor restoration, and the second, judged more successful, by the Italian master Pietro Bornia from the Vatican, effected in the apse and triumphal arch (Figs. 8-14) between 1890-97. But the documents tell a different version, as revealed in the following narrative chronology. In 1886 the Albert Neuhauser Mosaic Firm in Innsbruck did indeed restore mosaics, but it was only a trial restoration, and the area restored was not the west facade but rather the Annunciation in the apse (1887-D#0366; 1888-D#12773/ix), a panel often singled out for praise (Fig. 13). Further blurring any conflation of quality with nationality, the documents identified the mosaicist in charge of this trial as an Italian named Solerti (1888-D#0799). Solerti was contracted to restore 5.6 sq m of the scene, considered one of the most damaged areas in the apse, but ended up restoring 12.8 sq m (1888-D#12773/ix). The Annunciation is doubly instructive in this regard, serving as a warning to patriots and scholars alike. For it is possible that the Annunciation was re-restored by Bornia to "correct" faults introduced earlier. In 1893, funds were allocated for repairs to the Annunciation (1893-D#16396/ix), and plans to rework it appear in several documents (1893-D#16396); no record exists, however, to demonstrate that the plans were carried out. Although the Neuhauser firm argued with officials about their pay (1888-D#0799; 1888-D#12773/ix), the initial response to this trial was positive, and discussions about a full restoration ensued. But dissatisfaction arose within a year (1887-D#0366). A report from the Statthalterei in Trieste informed the MCU that the trial had "not quite turned out" (1888-D#12773/ix: der nicht ganz gelungen ist). Conservator Count Franz Coronini, in a letter to the CCD, pulled no punches. Having seen Solerti's work during a visit to Istria, he wrote that they were of such poor artistic merit that they were "painful to behold" (1888-D#0863: dass sie den Beschauer wahrhaft schmerzlich berühren). The records do not specify the shortcomings, but we learn from indirect and parenthetical comments that technique and use of gold were at issue (1889-D#0137; 1891-D#0467).

As an alternative, the CCD turned to the Salviati enterprise in Venice. Salviati's name had appeared in 1876, when interest in a restoration first began (1876-D#0346/0348), and a year later, when Dr. Salviati was contacted for an estimate, he gave his assurance that either he or an artist from his mosaic factory would come to examine the mosaics (1878-D#14145). In a letter of November 17, 1887, Pietro Saccardo, an engineer associated with the restoration of the mosaics at S. Marco in Venice, warmly recommended Salviati and the mosaic school at S. Marco to the CCD (1888-D#0932). In June of 1888, the MCU decreed a second trial restoration, this time by Venetian artisans (1888-D#12773/ix), an action which was received with disfavor by Parentine officials such as Andrea Amoroso, Deperis and others (1888-D#0799(2); 1888-D#0863). Their last minute, behind-the-scenes campaigning, supported by Josef Mathias von Trenkwald, a member of the CCD, and Baron von Helfert, then president of the CCD, successfully steered the job to a third party, Pietro Bornia from the Vatican in Rome (1888-D#0799). Bornia and his assistant arrived in Parenzo December 4, 1888 to begin a trial restoration of the scene of the Visitation (Fig. 14), on the south side of the apse (1888-D#1280). Within a month he had restored 3 sq m of the panel, and cleaned an additional 10 sq m (1119-D#0012). The trial was deemed a success (1888-D#1280; 1889-D#0012; 1889-D#0137), and, spurred on by an imperial decree releasing State funds (1889-D#1337), the MCU issued a contract for a comprehensive restoration of the mosaics (1890-D#0513). The four-year contract stipulated that Bornia and his assistant work for 6 months out of each year. The actual project lasted for a full decade, from 1890 to 1900. For the purposes of this review, it can be divided into two phases, the first lasting from 1890-95, and the second from 1895-1900.

Phase I (1890-95) began with a surprise. No sooner had the scaffolding been set up than the discovery of the mosaics on the triumphal arch commandeered all the attention (1890-D#0639). Natale Tommasi, an architect and engineer for the Statthalterei, found the representation of Christ and the twelve Apostles (Figs. 18-19) under a more recent cornice on May 23, 1890. The figures stood against a gold background, the whole surrounded by a red, jeweled border. While a fracture in the wall had completely destroyed the face of Christ (Fig. 18), and two other figures had been heavily damaged by the insertion of wooden supports for the cornice, the upper halves of other figures (Fig. 19) were relatively well preserved (1890-D#0729/D#0733). The lower half of the mosaic had been entirely lost. The records of the two following years are filled primarily with correspondence about how a restoration of this newly discovered mosaic might be incorporated with the apse, and thus we have imperfect records of Bornia's progress during this period.

Phase I was dominated first by work in the apse, and then on the triumphal arch. Bornia began with the figures in the apse, finishing all but those between the four windows by 1891 (1891-D#1546). By the Fall of 1893, all figural and ornamental parts of the apse had been completed with the exception of the drapery of the saint to the south of the Virgin, and parts of the clouds, much of which had to be replaced (1893-D#16396/D#26735). In 1893, Bornia filed his own report, detailing his plans (1893-D#0984): In 1893 he would finish the gold haloes of all saints in the apse and the gold ground between the saints on the south side; Scheduled for 1894 were the spandrels and areas around the four windows, an area of gold 1.56 m square on the north side of the arch, an area of .4 sq m on the south side, near the saints, that had been attacked by wall rot, and also the gilding of damaged parts of the semi-dome. Documents of 1894-95 have little to say about the apse, probably because discussion had already shifted to the triumphal arch and other areas. But work on the apse had not been fully finished, as late October of 1894 found Bornia still laboring over the gold background (1894-D#1643).

The documents detailing the restoration of the triumphal arch have a different tenor, being full of the debate over how best to handle the lost parts of the mosaic. While the officials did not want to introduce elements for which no material evidence existed, most agreed that leaving the lower half of the mosaic empty, or in radically different form from the upper, would be an eyesore (1890-D#0930). The first proposal, Trenkwald's, was to restore the upper figures as had been done in the apse, and then to substitute the lower half of the panel in wax tempera paint (1891-D#0467; D#1473). That way, the image would be complete, but the limits of the original would also be immediately apparent. The CCD and MCU both resisted that solution, arguing instead that the lower half of the panel ought to be executed in mosaic (1891-D#1473). The official decree from the MCU in 1892 ordered the work to be done in mosaic, or, if the budget would not allow, then stucco (1892-D#0051). One would think, especially since the decree claimed support from the principals (CCD, Bornia, Amoroso), that the issue was then solved, but apparently not. In 1893, Amoroso took matters into his own hands and instructed Bornia to seek the counsel of specialists in Rome, from Professor Gai at the Academia di San Luca, and the most revered authority on early Christian antiquities, Commendatore Giovanni Battista de Rossi, whose name figured so prominently in the spirit of the XIII congressus internationalis archaeologiae christianae. Their advice about the lower half of the panel, a confident Amoroso wrote to Trenkwald, was to use mosaic, but to outline the missing figures, which they felt certain had been standing apostles flanking Christ seated on a globe, in black against a ground similar to fresco in color. Gai and De Rossi also recommended, in contrast to the official Austrian decision (1893-D#614), completing the jeweled border which had survived on three sides of the triumphal arch, by adding it to the bottom (1893-D#0614). These suggestions were accompanied by Gai's full-size painted cartoons and outline drawings (1893-D#0614; 0984). Trenkwald, in his advice to the CCD, was in agreement with the Roman specialists but displeased with Amoroso's unilateral action (1893-D#0719). The final change of plans, in which it was decided to remake the bottom completely in mosaic without outlining in black or substituting neutral hues for gold, is not in the record. They chose to distinguish the remade lower half of the mosaic from the restored upper half by weaving a horizontal line of bright red tesserae through the panel (Figs. 9-11).

Reports from 1893, including one from Bornia, provided fairly detailed information about his progress and intentions (1893-D#0984; D#16396/ D#26735). Bornia began with the south side of the panel, finishing the restoration of the upper halves of four apostles in 1892 (Fig. 10). In 1893 he projected completing Christ and the upper halves of two additional apostles (Fig. 9), part of the gold ground between the figures, the jeweled band, and placement of a horizontal band. The upper halves of the remaining six apostles (Fig. 11) would be finished in 1894-95, along with the manufacture of the lower halves of the figures. The last mention of Bornia's progress on the triumphal arch, in a document from 1894 (D#1156), suggested he had encountered difficulty with some of the figures, and noted what remained undone: two half figures, a section of feet, and the green ground under the apostles, which was to have been strewn with flowers.

Officials were also uncertain how to handle the spandrels above the apse and below the triumphal arch, since no traces of the original design remained. In 1891, Trenkwald, with the support of the CCD, suggested they be filled with glass paste tesserae of a neutral color (1891-D#1473), a plan adopted by ministerial decree in 1892 (D#0051), and carried out by Bornia in 1893 (D#0984). But the outcome was unacceptable in appearance, and in 1894, Bornia was instructed to remove the restored tesserae and replace them with gold (1893-D#16396/ D#26735), a task completed between 1895-96.

The mosaics of the apse and triumphal arch were reportedly finished by the end of 1895-96 (1896-D#0645; 1897-D#1144), but many details must have remained, since the scaffolding was retained until 1899 (letter of 1899 found in 1898-D#0421). Finally, in 1898 and 1899, the Venetian mosaicist Giovanni Moro-Lin, hired to work on both the pavement and wall mosaics, cleaned the newly restored mosaics of the arch and apse (1898-D#0421; 1899-D#1807).

Part II (1895-1900) of the restoration was less cohesive, the goals shifting with budgetary uncertainties and the process marred by conflict between the authorities. The major areas restored were the side apses and the lower western facade, but those plans, since no long-range, multi-year project existed, took shape on a year to year basis. Bornia, now in his 70's, figures less prominently, his assistants assuming more significant roles. How much of this was due to his preoccupation with the charges levied against his work in Parenzo by the Roman architect and inspector of ancient monuments Giacomo Boni, and how much of it was due to his age is not clear. The documents are not explicit on this question, so one must read between the lines. But no such discretion surrounds the conflict between Tommasi and Amoroso, a clash both of principles and personality which, at several points, leaves the projects at the cathedral without a clear mandate.

Even before Part I of the restoration was completed, Bornia was assailed internally and externally. In 1893, Amoroso, then general supervisor and financial manager of the project, proposed that Bornia and his two Venetian/Roman assistants be discharged (1893-D#0984). Amoroso wanted to save money. Much of the most important work (figures) was finished or well underway, and he was impressed with the talent of the local Parentine assistants, Lorenzo Sfereo and his son, Rodolfo, whom he judged capable of bringing the job to a satisfactory conclusion. Trenkwald, acknowledging the great skill of the Sfereos, was nevertheless alarmed at the thought of dismissing Bornia. Should they decide to restore the side apses, a proven master such as Bornia would be crucial (1893-D#0984). Bornia stayed, but it would appear that the Venetian/Roman assistants did not. That the Sfereos took on increasingly larger roles is evident from a document later that same year which noted that Bornia would be responsible for the figures on the triumphal arch, while the Sfereos would do the rest after Bornia's return to Rome (1893-D#16396/ D#26735). Thus, Bornia must have trusted them to work independently.

Bornia also drew fire from the outside, with the publication in 1894 of Boni's criticisms of the technique and character of restoration at Parenzo. Authorities both in Italy and Austria came to his defense. The documents record approval of Bornia's work (1894-D#1003) and, more importantly, Deperis quickly published a refutation of Boni. Deperis' article, meant to settle the matter, only intensified the conflict. Boni published an article countering Deperis' refutation, to which the Monsignor responded with yet another, and more heated, refutation. According to Tommasi's report of 1895, the situation caused Bornia great distress (1895-D#0817). The Austrian officials decided to take a dignified public stance and stay above the fray, though they maintained their support of Bornia (1895-D#0955). Later, in 1897, the CCD, in a document written by von Helfert, expressed more ambiguity about Bornia. In contemplating a restoration of the gable of the west facade, he suggested that some of Boni's criticisms might have been valid (1897-D#1144). Since the work already done inside the church was not, von Helfert noted, being viewed favorably in Rome, any mishandling of the very fragmentary and exceedingly rare mosaics of the upper facade would, "trigger a storm of outrage from all Christian archaeologists from Berlin to Palermo, and of all real and imagined experts of restorative technique." On the one hand praising Bornia, the report went on to note his advanced age, the possibility of his resignation, and reflect on the question of engaging a new master. While one reads increasingly of the Sfereos, Bornia is still in charge in 1898, when he assured the bishop, who wished to have the scaffolding removed, that he had finished in the apse and no longer needed the scaffolding (1898-D#0084). Bornia's actual departure from the project is not recorded, but the final mention of his name occurs in 1900 (D#0436/D#0437).

Additionally, tensions between Tommasi and Amoroso, which had been brewing (1894-D#1156), erupted in 1895, leading to Amoroso's resignation from management of the funds (1895-D#1030). While full details are omitted, Austrian officials such as Trenkwald expressed fear about Tommasi's tendency to overreach his authority and expertise (1895-D#1030). His retreat notwithstanding, Amoroso remained active as a corresponding member, submitting a report just several months after his resignation (1895-D#1843). The wrangling, often over questions unrelated to the wall mosaics, continued through the next several years (1898-D#0563; D#1360). While gaps in the documents rob us of precise information about the chain of command at any given moment, their respective influence seems to have see-sawed. First Tommasi appears to triumph, being appointed corresponding member in 1896 (D#1941), and then given full and exclusive and charge of the finances in 1898 (D#25415), but Amoroso remained active in some capacity at least until 1908 (D#0790), long after the documents ceased to mention Tommasi's name. One can only speculate as to the impact this divisiveness had on the restoration of wall mosaics. Certainly Tommasi was very deeply engaged in architectural and other activities at the cathedral, the details of which dominate the CCD documents of the second half of the decade.

Amidst all this uncertainty, the mosaics of the side apses and lower west facade were restored, albeit without the grand and adequately funded design that had guided work in the apse and triumphal arch. As the side apses and facades raise different kinds of questions, they are discussed separately. First the side apses (Figs. 4-5): It has been assumed that they remained untouched until Molajoli's work of 1936, itself poorly recorded, but the documents reveal that they were restored during 1896-97. The need for a restoration of the side apses had been apparent since 1881 (D#9110), became the focus of repeated discussion in 1893 (D#0984; 16396), and was finally acted upon that same year, when a decree released funds for the consolidation and completion of existing figures (1893-D#16396/26735). Work began in the Spring of 1894 (1894-D#0645), and, surprisingly, Lorenzo Sfereo emerges as the sole mosaicist (1896-D#1433; D#1674). Most of our information about their condition and restoration comes from a description by Bornia in 1893 (1893-D#0984), and two reports by Amoroso from 1896 (1896-D#1433; D#1674). The mosaics in the north apse (Fig. 5), which were very loose, lay against the wall only "by a miracle" (durch ein Wunder: Trenkwald's translation of Amoroso in 1896-D#1433). The roof lacked proper drainage, and the humidity which penetrated the wall had eventually rotted the base of the mosaic. The mosaics in the south apse (Fig. 4), by contrast, were in relatively good repair. Bornia noted that the jeweled band around the apses would have to be almost completely made anew (1893-D#0984). The work done on the side apses was less invasive than that done elsewhere, amounting primarily to repairs and consolidation, since the funds which might have permitted the full restoration of existing areas and the manufacture of lost parts never materialized (1896-D#1433; 1897-D#1144). For example, the ornament (rinceaux) on the walls above the apses and the jeweled bands, which, deemed less urgent, had been left for later (1896-D#1674), were never finished.

The extremely ruinous external facades appeared repeatedly in proposals for restorations, amid repeated and urgent cries of imminent destruction. The gable of the upper west facade and the full eastern facade were the most poorly preserved parts. Figs. 20-21 illustrate the facades during the 1860's-70's. While these artists, we had best assume, took some liberties in their depictions, significantly more of these facades survived in the third quarter of the nineteenth century than do now (Figs. 6-8). Indeed, an alarming rate of deterioration was a persistent theme in the calls for restoration from the first mention, in 1881 (D#9110) to the final mention, a reference to insufficient funds, in 1900 (D#0302). Today, one sees only patches of tesserae clinging to a worn mortar base (Figs. 6-8). The main issue, as one well might guess, was how best to preserve such fragmentary remains. Various options were discussed. The least ambitious was mere protection from the elements, covering the tesserae either with wooden planks and a shallow makeshift roof of sheet metal or tar paper (1891-D#0467), or a layer of mortar (1891-D#1546). Consolidation and repair of the remains that existed represented a middle ground (1881-D#9110). A complete restoration, more invasive, was considered at several points, especially in the late 1890's. Tommasi's proposal for a five-year, comprehensive program of restoration, which was to include the replacement of all missing parts, was considered favorably by the authorities (1897-D#1144; 1898-D#6115), but, for uncertain reasons, never came to pass. Finally, the most radical option, removing the panels for storage, under active discussion in 1893 (D#0498; 16396/D#26735; 1511), was rejected in 1894, the authorities noting that consolidation in situ would not cost any more (1893-D#16396/D#26735; 1894-D#1643). In 1891, realizing that a final decision might not be forthcoming for some time, and the deterioration having progressed sufficiently that securing wooden planking threatened the detachment of several areas of mosaics, the gables of both facades were covered with mortar (1891-D#1546; 1893-D#1511). The measure, as Amoroso explained, would buy at least a decade's time in determining a more permanent solution.

As it turned out, the lower register of the west facade, with its 4 holy figures and 7 candelabra, not coincidentally the best preserved area, was the only part of the facades to be restored (Figs. 9, 15). A photograph taken about 1900, from the archives of Gabriel Millet in Paris (Fig. 22), illustrates their condition prior to restoration. It confirms the information from the documentary record in that the figures on the north were better preserved than those on the south (1891-D#0467). The actual restoration began in 1896 and continued at least through 1900. Bornia was to take charge of the heads, haloes, hand and feet of the four holy figures, while the rest, the base and background, would be done by Lorenzo Sfereo; the window ornament, candelabra and corner pilasters would be left to another year (1896-D#0645). Amoroso reported in September of 1896 that Bornia had been in Parenzo for three months, working on the heads, hands, crowns and feet of the north figures; Sfereo was currently working on the drapery of the figures, and the terrain under their feet; and thus the two north figures would be complete that Fall (1896-D#1433; 1674). At the last mention of the facade mosaics, in 1900, the intrados of the window arches and pilasters were still not finished (1900-D#0436/0437). Thus the lower west facade, supposedly restored first, was actually the final aspect of the restoration of the wall mosaics at Porec.

The documents do not mention the difference in quality between the facade mosaics and those in the main apse and triumphal arch, a contrast apparent to contemporary viewers. One might suspect Bornia's age, of such a concern to officials during the later 1890's, might be the culprit. That the Sfereos had taken successively greater responsibilities does not necessarily implicate them, as other sections credited to them (the side apses; Figs. 4-5) do not carry the same flat and awkward qualities of the holy figures on the facade (Fig. 15).

This set of documents contains surprisingly little about the methods, techniques and materials used in the restorations. But indirectly, one may piece together an outline of the process, and identify certain issues that troubled restorers. Of greatest interest, different methods of restoration were used for the apse than for the triumphal arch and west facade. They began in the apse, by cleaning away 1300 years of grime, and repairing damage from earlier patching. Areas where the mosaics had separated from the wall and were hanging loose, primarily in the semidome itself, were reattached with 10-30 cm-long serrated copper nails and pegs driven into the mosaic at regular intervals. When the acid used to clean the surface oxidized the copper, the green stain had to be removed. Repairs and restorations followed the cleaning. While there were not many very substantial repairs, nearly every section needed some work. The figural areas most in need of restoration (in addition to the Annunciation and Visitation, the reasons they had been chosen for the trials) were the figures between the windows, and the Virgin and figures flanking her. Most areas using gold tesserae needed attention, since most of the gold tesserae had lost their top layer of glass with its gilding. The most substantial repairs among the ornaments and borders were in the corners of the spandrels of the window arches, and at certain places in the center and on the periphery of the apse. Frequently, when loose areas of mosaic were reattached, or small sections repaired, the neighboring tesserae would fall to the ground and then have to be placed in a new mortar bed. The only part of the apse that was completely remade was the lamb in the intrados (Fig. 3), a misinterpretation, as others have noted, but based on imprints in the mortar.

A radically different approach to restoration was used on the triumphal arch and west facade, where Bornia followed a four-step process: (1) he produced colored copies; (2) he detached the mosaic in sections; (3) he restored them on a bed of sand (1896-D#1674); and (4) he reattached them on a new mortar bed. For example, in 1894, Trenkwald watched as Bornia tested the placement a number of feet (from the Apostles on the triumphal arch); final attachment was left until the following year (1894-D#1643).

The gold tesserae presented the single worst problem. While all other glass and marble tesserae took on their original color and brilliance after cleaning, these, whose thin surfaces of gold had been worn away over the centuries, remained a dull dark brown or black. Authorities wanted to replace them all with new gold paste, but, because many of the original gold tesserae were firmly attached to their base, Bornia expressed great anxiety about that solution. He feared that a wholesale removal of the once-gold tesserae would destabilize the essential fabric of the entire mosaic. A further complication, the gold tesserae available, made in glass shops in Venice, having a modern looking hue and a "glaring mirror finish," pleased no one (1893-D#0614). The solution adopted, first suggested by Trenkwald was to overlay the original tesserae with double gold leaf, and then cover them with varnish (1891-D#0467). Once covered with varnish, the gold foil would immediately drip into the joints and each tesserae would retain its separate demarcation. Only a close physical examination of the mosaics would determine how thoroughly this solution was applied, but dissatisfaction with the gold continued to be a concern right through the end of the restorations.

The documents are a wellspring of information about the restoration of the wall mosaics at the cathedral in Porec, giving us firm dates and names, significant insights into general methods and procedures, and a vivid sense of the personalities involved and their philosophies of conservation. But equally important is what this particular group of documents does not reveal. We do not learn, in any consistent or detailed fashion, exactly what treatment--mending, reattaching, repair, replacement--each detail of each figure underwent. Similarly, how closely the restorations of the figures and images in the apse mosaic followed the originals, a most crucial issue, remains poorly defined. These and other questions must await the recovery of additional documentation and a close physical analysis of the mosaics themselves.


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