The pilgrims who for years have been used to pray in the Grotto in the Basilica of the Annunciation in Nazareth are slightly disappointed to find entry barred with a sign inviting them to remain outside the fine wrought iron balustrade.
At the origin of this decision, recently taken by the Franciscans in service at the sanctuary, is a situation of deterioration of the rock of the Grotto which has reached a critical and worrying stage.
For many years, the rock of the Grotto had shown a clear sign of progressive deterioration of the stonework, in particular the vault. Despite the many treatments it had undergone since the 1980s, the rock continued to show visible structural incoherence, with the fall of fragments of stone from the vault. At times it was only dust but sometimes the pieces were larger, becoming a cause for concern.
There are various reasons for the origin of this superficial crumbling. First of all, there is the nature of the rock of the Grotto, which continues in the church the hill on which the town of Nazareth stands. It is a very brittle white rock, almost marl, which geologists call chalk. This material is very easy to work, so that the pilgrim-sculptors who came from France and decorated the new Basilica of the Annunciation built in the times of the Crusades, used it for the splendid capitals with the history of the Church and the stories of the Apostles that can be seen today in the small museum near the sanctuary (and which obviously run the same risk as the rock in the Grotto!).
The Franciscans came into possession of the Grotto and of the ruins of the Crusader church – destroyed in the 13th century by order of the sultan Baybars ad-Dhahir - in 1620, when the Druze emir of the Lebanese mountain Fakhr ed-Din gave it to Father Tommaso Obicini da Novara Custos of the Holy Land, writing a fine page in the history of the friendly relations between the Muslims and the Franciscan Custody of the Holy Places. In the restoration which followed the gift, the church was rebuilt and the Grotto inside protected and honoured by a slab of marble outside and inside, partly responsible for the start of the deterioration because the rock, prevented from breathing and freely interacting with the surrounding environment, began to lose cohesion due to humidity.
In 1974, when the new grandiose basilica designed by the architect Giovanni Muzio was completed, the last work was on the Grotto, from which the stone facing was removed, choosing an aesthetically pleasing and emotively effective solution. Of the old monumental altar with columns and decorative sculptures, only the communion table with the star below it, which recalls the mystery that is celebrated in that Grotto, remains. In the new cement church, the Grotto remains isolated and bare under the large conical dome, between the Crusader wall behind it and the remains of the mosaics of the first early Christian church in which it was incorporated from at least the 4th century. This solution was another shock for the Rock, having to cope with a new microclimate.
Unfortunately it was a damp microclimate, aggravated by a pious practice which became common until the recent enclosure: that of letting large groups of pilgrims enter the Grotto with a fairly modest capacity and halt there, although the experts had advised against this and, for a certain period of time, this was respected.
Initially the fine wrought iron gate by the Austrian artist Hermann Pedit was conceived to protect the Grotto, to prevent access by groups. It is difficult for the visitor, let alone the pilgrim, to understand that our bodies give off moisture and carbon dioxide, both of which are damaging and harmful if multiplied infinitely and together with the other natural causes which are already a problem.
Research has been started to highlight the factors of the deterioration and the ways in which this deterioration takes place. From the day it was closed last November, three hygrometers (which measure humidity) in the Grotto, on the steps at the back of the Grotto and outside the Basilica, are doing a first study to record the thermal and humidity parameters. These sensors can measure, monitor and record the temperature and the humidity of the air, but also of the rock of the walls.
This is the first and sole reason why , for the time being, the decision was taken to temporarily close the access to the Grotto, in order not to further alter the rates of humidity.
The data collected is analysed through appropriate calculating programmes, which make it possible to monitor the exchanges between the rock and the surrounding atmosphere in view of the final work.
In parallel, some experts have arrived from Florence to begin the three-dimensional scan of the Grotto, which will then be re-elaborated to have an exact documentation of the rock surface on which to work.
The first petrographic tests on some fragments of stone taken in the Grotto have been carried out in the laboratory of the University of Florence. This examination was followed by the direct experimentation which consisted of treating the fragments collected with appropriate products (called nanoparticles) to restore to the brittle rock its original coherence and compactness. In practice, products are inserted into the calcareous formation which – without creating layers of insulation which have been revealed as damaging in previous work – can aggregate the rock particles, giving them cohesion.
The laboratory results are very encouraging, we were told by Prof. Piergiorgio Malesani, who directs the group of young experts of the Centre of excellence, who put themselves at the service of the Sanctuary with enthusiasm and competence.
The pilgrims need not worry. At the end of the work, they will be able to visit the sanctuary with the certainty that the Grotto – venerated as part of the House of Mary since the very first centuries – protected and honoured by the places of worship that have followed on one another over the centuries, will be able to face the centuries to come with safety and stability.
Fr. Michele Piccirillo ofm
At the origin of this decision, recently taken by the Franciscans in service at the sanctuary, is a situation of deterioration of the rock of the Grotto which has reached a critical and worrying stage.
For many years, the rock of the Grotto had shown a clear sign of progressive deterioration of the stonework, in particular the vault. Despite the many treatments it had undergone since the 1980s, the rock continued to show visible structural incoherence, with the fall of fragments of stone from the vault. At times it was only dust but sometimes the pieces were larger, becoming a cause for concern.
There are various reasons for the origin of this superficial crumbling. First of all, there is the nature of the rock of the Grotto, which continues in the church the hill on which the town of Nazareth stands. It is a very brittle white rock, almost marl, which geologists call chalk. This material is very easy to work, so that the pilgrim-sculptors who came from France and decorated the new Basilica of the Annunciation built in the times of the Crusades, used it for the splendid capitals with the history of the Church and the stories of the Apostles that can be seen today in the small museum near the sanctuary (and which obviously run the same risk as the rock in the Grotto!).
The Franciscans came into possession of the Grotto and of the ruins of the Crusader church – destroyed in the 13th century by order of the sultan Baybars ad-Dhahir - in 1620, when the Druze emir of the Lebanese mountain Fakhr ed-Din gave it to Father Tommaso Obicini da Novara Custos of the Holy Land, writing a fine page in the history of the friendly relations between the Muslims and the Franciscan Custody of the Holy Places. In the restoration which followed the gift, the church was rebuilt and the Grotto inside protected and honoured by a slab of marble outside and inside, partly responsible for the start of the deterioration because the rock, prevented from breathing and freely interacting with the surrounding environment, began to lose cohesion due to humidity.
In 1974, when the new grandiose basilica designed by the architect Giovanni Muzio was completed, the last work was on the Grotto, from which the stone facing was removed, choosing an aesthetically pleasing and emotively effective solution. Of the old monumental altar with columns and decorative sculptures, only the communion table with the star below it, which recalls the mystery that is celebrated in that Grotto, remains. In the new cement church, the Grotto remains isolated and bare under the large conical dome, between the Crusader wall behind it and the remains of the mosaics of the first early Christian church in which it was incorporated from at least the 4th century. This solution was another shock for the Rock, having to cope with a new microclimate.
Unfortunately it was a damp microclimate, aggravated by a pious practice which became common until the recent enclosure: that of letting large groups of pilgrims enter the Grotto with a fairly modest capacity and halt there, although the experts had advised against this and, for a certain period of time, this was respected.
Initially the fine wrought iron gate by the Austrian artist Hermann Pedit was conceived to protect the Grotto, to prevent access by groups. It is difficult for the visitor, let alone the pilgrim, to understand that our bodies give off moisture and carbon dioxide, both of which are damaging and harmful if multiplied infinitely and together with the other natural causes which are already a problem.
Research has been started to highlight the factors of the deterioration and the ways in which this deterioration takes place. From the day it was closed last November, three hygrometers (which measure humidity) in the Grotto, on the steps at the back of the Grotto and outside the Basilica, are doing a first study to record the thermal and humidity parameters. These sensors can measure, monitor and record the temperature and the humidity of the air, but also of the rock of the walls.
This is the first and sole reason why , for the time being, the decision was taken to temporarily close the access to the Grotto, in order not to further alter the rates of humidity.
The data collected is analysed through appropriate calculating programmes, which make it possible to monitor the exchanges between the rock and the surrounding atmosphere in view of the final work.
In parallel, some experts have arrived from Florence to begin the three-dimensional scan of the Grotto, which will then be re-elaborated to have an exact documentation of the rock surface on which to work.
The first petrographic tests on some fragments of stone taken in the Grotto have been carried out in the laboratory of the University of Florence. This examination was followed by the direct experimentation which consisted of treating the fragments collected with appropriate products (called nanoparticles) to restore to the brittle rock its original coherence and compactness. In practice, products are inserted into the calcareous formation which – without creating layers of insulation which have been revealed as damaging in previous work – can aggregate the rock particles, giving them cohesion.
The laboratory results are very encouraging, we were told by Prof. Piergiorgio Malesani, who directs the group of young experts of the Centre of excellence, who put themselves at the service of the Sanctuary with enthusiasm and competence.
The pilgrims need not worry. At the end of the work, they will be able to visit the sanctuary with the certainty that the Grotto – venerated as part of the House of Mary since the very first centuries – protected and honoured by the places of worship that have followed on one another over the centuries, will be able to face the centuries to come with safety and stability.
Fr. Michele Piccirillo ofm