1700 /1800
The first remarks regarding the state of conservation of the Chapel's frescoes appear in a guidebook published at the end of 18th century. The author, a certain Brandolese who was a local scholar, found the condition of the murals to be quite good.
Nevertheless, only thirty years later, another local figure, Rumohr, made a distinctly pessimistic evaluation of their condition saying that they were in a "most sorry" state because they had been roughly washed by hand and then painted over in tempera. His claim created perplexity, however, since no trace of this over-painting has been found, least of all in such a generalised way. Greater credibility can be given to the specific remarks on the condition of several pictures, or parts of Giotto's cycle, made ten years later by Pietro Selvatico.
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1817
In 1817, the portico on the facade of the Chapel collapsed, and ten years later the palazzo alongside the Chapel was practically demolished.
Whoever was concerned with such problems at the time, in any other than an amateurish way, had a clear understanding of the protective function of these two structures. And, in fact, Moschini, when announcing the collapse of the portico, hastened to add: "so the wall paintings inside the Chapel will be badly affected." Subsequently, Cavalcaselle put forward the idea of applying "compact mortar" to the external walls, in particular to the north wall and the facade. In that period (1857), the facade had not yet been reduced to exposed brickwork but was decorated with frescoes that are recorded in a photograph taken in 1865.
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1871
In 1871, to make it possible to restore the main arch without damaging the paintings, Guglielmo Botti was commissioned to detach portions of the frescoes and to put them back in place once the wall had been consolidated. Two years previously, this same restorer had done work on the wall of the Last Judgement to make the painted layer adhere to the plaster surface, and the work had turned out most satisfactorily. Nevertheless, the restoring techniques used by Botti on another important cycle of Paduan mural paintings dating from the 14th century (Oratorio di San Giorgio), had aroused heated arguments and so the restoration of the complete decorations of the Chapel was entrusted to Antonio Bertolli, a Paduan painter and restorer. But work did not begin until the necessary conservation work had been done on the monument.
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1881
As can be seen in a letter from the mayor, sent on July 2, 1881, to the director of the works, Maestri, the projected restoration of the Chapel was to include "restoring its original style". The municipal commission, "from prudence" and in homage to "history's jealous reasons", had considered it feasible to have executed only those things that concerned the conservation of the incomparable monument [...] "without additions or reconstruction", such as excavations along the walls and in the piazza at the front of the Chapel or removal of the plaster "liberating the facade from the unseemly and absurd 17th century Baroque plastering". The letter concluded "The project will be of great service to the wall paintings by making their history legible and unveiling their simple and direct elegance without damaging them". If this was the opinion of the city's highest commission, it is easy to imagine what reception would be given four years later to the idea of covering the Chapel's outer walls with plaster in order to protect "the frescoes from ruin." In fact, it was unanimously rejected and only Maestri's decision to close holes and make other repairs in the outer face of the north wall was accepted.
On the same occasion, however, they urged an investigation employing scientific methods on the question of dampness in the walls to determine if this was responsible for the deterioration of the frescoes.
The investigation, entrusted to the chemist Pietro Spica, confirmed the theory that the walls bearing the "deteriorated" frescoes contained more dampness than the ones bearing the paintings in good condition. As to remedies, there was unanimous acceptance for Bertolli's idea to detach the two paintings in worst condition (The Dispute with the Doctors' and the Ascent to Calvary), to mount them on new copper frames and put them back in place after having made an air space so that the back of the frescoes would not come into contact with the damp walls. For those times, the solution was quite ingenious and entirely original. But primarily it seemed to be fully adequate for dealing successfully with the greatest difficulty, after which the general work on the frescoes could go ahead unhindered.
The frescoes were all restored, consolidated and cleaned, but without being retouched with paint, which the commission had expressly forbidden. Only a "neutral" stuccoing was allowed where the plaster was missing to obviate the disturbance that the sight of exposed brickwork might cause. The work continued for about ten years so that, by the turn of the century, the apparently endless task of rescuing Giotto's cycle seemed to have reached a happy conclusion.
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1885
The frescoes on the outside wall of the facade were demolished during the restoration of the monument right after the City Council had bought it (1880). Even before this, thanks mainly to the urging of the Commission led by Marchese Selvatico, the city had been able to intervene with operations to strengthen the structure that could not be put off without risking irreparable damage to the building and thus to Giotto's paintings. The isolation of the Chapel in consequence of the demolition of the palazzo, the damage done to it by the collapse of the portico, the lack of maintenance especially in the previous twenty years or so - all these had indeed made the static situation of the building precarious.
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1936
It was not until the beginning of 1936 that a message addressed to the Mayor drew attention to the rather alarming situation of the frescoes and the Chapel in general. The author of the message was the president of the reconstituted Conservation Commission (the first one having ceased to exist in 1928). He noted that the architrave of the portal was cracked, that the frame of the three-light window in the facade and the Chapel roof were not rainproof and, above all, that the cases of "discolouring and powdering in the frescoes" had increased in recent years. All that was attributable "almost exclusively" to dampness "rising from underground pools or rain water that had collected in the area below the Chapel". This phenomenon was aided by the fact that the north side of the building had remained below ground level whereas the southern side had been excavated to the level of the basement floor, including the windows.
Aside from the suggestion of a (partial) intervention, it is interesting to see the attempt at pinpointing the origin of the dampness since it has always been considered responsible for the particular type of deterioration affecting frescoes.
The need of a quick response to the problems came from two emergencies - the earthquake of 18 October of the same year and shortly afterwards the second world war. These were the reasons that caused the problem of so-called "non-traumatic" deterioration of the Giotto cycle, to be postponed yet again. The damage caused by the earthquake made it impossible to defer urgent consolidation work on the main arch. And then, during the war a project had been prepared for a reinforced concrete bunker. But only the foundation for this was laid on two sides of the building because of a shortage of construction materials.
The Chapel miraculously escaped destruction when the nearby Church of the Eremitani was bombed, and in particular the Ovetari Chapel. But the strong impression aroused by the event lasted a long time - so much so, that in the early 1950s an international commission held detailed discussions about how the Chapel could be saved in the event of another war.
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1952
Removing the dust that had been deposited in worrisome quantities on the paintings - primarily during the removal of war defences - was the main problem facing the frescoes soon after the end of World War II along with the consolidation of the powdery colours, blue above all. Given the wide extension of the blue areas, the two phenomena were often present at the same time. Consequently the problem became how to remove the dust that was partially mixed with the powdery colour with a minimum of damage to the latter. An attempt that the most famous Italian restorer, Mauro Pelliccioli, was allowed to make in 1952, was vigorously criticised with regard to both the materials employed (considered inappropriate, although widely used) and for having an inadequate methodological basis.
The Central Institute for Restoration (whose director, Brandi, had played a leading role on the International Commission) was given technical responsibility for the operation thereby creating the premises for an adequate solution to the problem. The novelty consisted in the possibility of using synthetic products that had been tested outside Italy and generally for industrial purposes. Now they were being introduced in the field of restoration. In the meantime, the general cultural climate had changed radically. Therefore the substitution of one product or technique for another, for example, was no longer left to the improvisations of the restorer, but entrusted to the evaluations of a multidisciplinary team. Furthermore, for the first time in the history of the Chapel's conservation, attention was given in a programmed way to the environment (in the microclimatic sense), not only to the frescoes and the supporting walls. Thus, at the beginning of the following decade, when work on the Giotto cycle was put in the hands of Leonetto Tintori, he was able to count on a supporting data that had previously been unobtainable.
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1961- 1964
Leonetto Tintori's restoration work continued for about three years, from 1961 to 1964, It involved the frescoes in the presbytery and the apse as well. Immediately prior to this, significant work had been done to improve the Chapel's static structure. With regard to the surroundings, aside from the excavations that were carried out at the base of the north wall (and the usual maintenance work on windows, doors, roof tiles, etc.) other work was not considered necessary since the amount of dampness had been found to be about normal; furthermore no traces were found of rising damp from below, and the situation in the basement seemed to have reached a balance and even to have a stabilising function. The most disquieting problem remained to be solved, however - the slow but progressive deterioration of the colour. This aspect had not been given as much consideration as it should have been, simply because the Central Institute for Restoration did not yet possess the equipment that would have allowed them to make the specific examinations that were possible in the better equipped Center for Conservation of the Fine Arts, New York University. The studies conducted at the Center showed, however, that the cause of that particular deterioration of Giotto's frescoes, which is to say, the colour's progressive turning into powder, was to be blamed on air pollution rather than other phenomena (dampness, past restorations) up to then considered to be if not the only reasons, certainly the principal ones. This phenomenon was so absolutely new, especially in a closed space, that it was not immediately possible to evaluate its importance. Quite a few years had still to pass before the problem was confronted in all its complexity with adequate methodologies and instruments. But already during the meeting of the International Commission, several interesting ideas had been put forward - for example, planting grass lawns in the areas in front of the Chapel (Coremans) or installing a double door to reduce the infiltration of dust from outside (Lo Vullo)
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1976
Twenty years after the suggestions made by the International Commission, the director of the Central Institute for Restoration, Urbani, visited the Chapel to check on the state of conservation of the frescoes. Neither of the two suggestions had been adopted or put into effect with the result that the paintings were once again in a bad state. He repeated those proposals and added several other elementary ones - asphalt paving for the pedestrian walks, the increased overhang of the roof, an annual check-up on the dampness that had seeped into the walls from the basement, and the repair of the cracks in the upper right-hand corner of the facade.
The severe earthquake that struck Friuli a few months later (1976) caused alarm for the Chapel's safety: the lesions in the facade and the vaulting worsened; furthermore a breach was created between these two elements of the building. By the end of the year the walls were repaired, as was the damage to the paintings. Immediately afterwards a plan was put into action for a scientific investigation planned and co-ordinated by the Central Institute for Restoration.
This was the first time that a monument had been the object of a global plan of programmed, interrelated research aiming to ascertain not only the agents and mechanisms of deterioration, but also what might be done to slow down the process as much as possible since it was impossible (but at the time this notion was not commonly held) to block it totally.
Since this initiative was immediately hailed as a "pilot project," the most important Italian research centres with experience in the field of conservation became involved in it, and the most advanced methods of research were activated.
Sulphation was found to be the principle mechanism causing deterioration of the painted layer, with pollution functioning as the main agent, dampness as the catalyst and dust as the adhesive.
The provisions indicated for making the surroundings into a suitable one were essentially of two kinds: since the point of entrance for dust and pollutants was the door in the facade, it would have to be closed and insulated, re-open the left side entrance and create an antechamber, "an air-conditioned reception area", located in the city park around the building. To eliminate temperature imbalances owing to the windows in the south wall and the incandescent light bulbs, double-glazing would be necessary, and tall evergreen trees would need to be planted. The incandescent light bulbs should be replaced with mercury vapour ones.
The project was not operative, nor was it intended to be; hence the solutions put forward were not acted on (nor was it the business of the Central Institute for Restoration to do so) and did not achieve technical and financial status.
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1985
Around the end of 1985, the Central Institute for Restoration was once again involved in putting the finishing touches to the real project as well as evaluating the need to restore the Giotto cycle. In case of a positive answer, they were to guarantee their readiness to take on the job themselves. The Institute, armed with past reflections on the matter, was convinced that relatively simple and economical measures could be taken, behind which stood a completely new way of viewing restoration work - aimed not only at the art work itself but also at the improvement of the environment in which that art work is located (so that the work would not require new restoration but, if anything, only check-ups and ordinary maintenance) without, in any case, being directly handled. The idea, in fact, was not to air-condition the Chapel itself but the "appendage", in other words, the reception area at the new side entrance. The difference, as one can easily imagine, is a substantial one - by air-conditioning an "auxiliary" area, connected to the Chapel but independent from a micro-climatic standpoint, one does not risk altering the fragile balance that has been established over the centuries between the frescoes, the walls and the inner ambience of the Chapel (clearly when there are no harmful or deteriorating agents at work).
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1988 - 1991
From 1988 to 1991, the Central Institute for Restoration systematically surveyed the state of conservation of the Chapel's wall decorations, documenting their findings either with drawings or photographs and making urgent repairs to the painted surface as they came upon them. A system for extracting sulphates from the painted layer on the plaster was worked out that was able to remove these harmful substances from the paint film, once the internal environment of the Chapel returned to normal.
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1991 - 1994
The City of Padua appointed a larger and more specific Scientific Commission of conservation experts for the programming and control of future diagnostic campaigns. The purpose would be to measure and control renovation operations on objects affected by deterioration and degradation, step by step, as they are discovered.
An extensive campaign of physical-chemical investigations was planned to detect and diagnose cases of deterioration in outdoor wall decorations, in particular those on facades. The procedure for restoring and conserving facades was put into operation.
New work sites run by the Central Institute for Restoration, started up yearly for the purpose of drawing up, mapping out, studying and making chemical-physical investigations to control deterioration, to take action locally in urgent cases and for the maintenance and conservation not only of Giotto's frescoes, but also of the whole Scrovegni Chapel.
A continuous monitoring system was installed to gather data and study the seasonal variations in the hygrometric exchanges between the frescoed surfaces and the internal environment. The project for continuous monitoring of air quality and the Chapel's microclimate was drawn up.
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1995 - 1996
The executive project was drafted for the new micro-climatic control unit (CTA) at the Scrovegni Chapel.
The monitoring system for the internal environment to measure the quality of the air in the Chapel went into operation. New operations were launched for checking the static structure of the Chapel, for lowering the water-table in the terrain around the Chapel, and for recovering the concrete reinforcement constructed during the second world war.
The Institute cleaned and restored the statues by Nicola Pisano on the main altar.
The City Council opened the work site for the realisation of the new micro-climatic control unit (CTA).
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1997- 1998
The City Council drew up the executive project and prepared the outside area for the micro-climatic control unit (CTA) and the connection with the Eremitani Museum.
The new entrance to the Chapel was put into working shape and opened on time. At the same time, the old entrance was closed and insulated while a new annual campaign of microclimatic monitoring was undertaken. Meanwhile new historical data was acquired on previous restorations.
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31 maggio 2000
The micro-climatic control unit (CTA) was activated. A year later, after a period of monitoring which was indispensable for verifying the effectiveness of this measure, the actual restoration of the frescoes began.
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June 12, 2001
At a public meeting in Padua's Eremitani Museum, the definitive restoration project was presented, including the top priority operations. The project was partly based on the data collected during the year since the micro-climatic control unit (CTA) had been put into action. The results achieved by the new system proved to be wholly positive, and it was therefore possible to start the definitive restoration project. From that point, the restoration work was completed in less than a year.
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