Sandra Plantier, an associate professor of secondary education in geography at the National Higher Institute of Teaching and Education, says that tree harvesting is archaic, and that replacing the former structure with oak trees as opposed to a modern, sustainable alternative could even end in the same result.
“Making the deliberate choice to cut down a thousand hundred-year-old trees to reconstruct the spire of the cathedral and its framework can only appear as a blindness to reality, or, worse, as an inability to draw lessons from the current situation,” she says in a column for Reporterre.
“These thousand trees, one or several hundred years old, are as many cathedrals for the biodiversity of our forests that we are getting ready, for the first, to cut down at the very beginning of spring, even though they will nest there probably already birds and squirrels.”
Work to restore the cathedral is not expected to begin until the beginning of 2022. Carpentry experts say rebuilding Notre Dame as it was will take 2,000 metres squared of wood, requiring about 1,500 oaks to be cut down. The cathedral’s roof contained so many wooden beams it was called la forêt (the forest). The roof’s support included 25 triangular structures 10 metres high and 14 metres across at the base, placed over the stone vaults of the nave.
Notre Dame is seen at the submerged bank of Seine River after continuous rainfalls in Paris
Geologists are studying about ten quarries north of Paris to find the same limestone as that mined for the cathedral underneath the French capital. That vast network of quarry tunnels beneath Paris was closed in the 18th century as collapsing galleries created dangerous sinkholes in streets and fields around the city.
Workers need new stone to rebuild collapsed parts of the vault and replace blocks in the gables over the three main entrances and other sections high up the side walls that were weakened by the fire.
Experts have been carefully testing the strength of surviving stones with everything from radar beams to simple mason’s hammers. Some stones that fell from the vault can be reused, but others have lost their inner solidity.
At the end of January 2021, fifty-two wooden support vaults left the Le Bras workshop for Paris, for the purpose of reinforcing each of the five stone vaults of the cathedral that were weakened or damaged, or sometimes gutted by the collapse of the spire during the fire of April 15th, 2019.
Assembly at the cathedral will begin in February 2021, thirty meters above the void: the supports will have been previously mounted under the vaults using hydraulic jacks.
On New Year’s Eve, electronic veteran Jean-Michel Jarre returned for a highly unique digital concert. Titled “Welcome To The Other Side,” the performance was filmed in a French studio but broadcast live in virtual reality (VR) inside a digital rendering of the Notre Dame de Paris Cathedral. Viewers could either tune in using VR or watch the set as a video on any device.
Of the medium, Jarre said,
“Virtual reality is to the performing arts today what cinema was to the theatre in its early days, a kind of curiosity. I believe that VR will become tomorrow, a mode of expression in its own right.”
The need to build scaffolds up to 40 metres high for the 200 workers to repair the high walls and soaring vaults has given art restorers the opportunity to study up close the side chapel ceilings they had no access to before.
They are finding traces of rich polychromatic decorations under the dark levels that have built up over centuries of candle smoke and air pollution. Medieval cathedrals were often covered inside and out with paint that either wore off or was hidden as unfashionable in later eras.
“We’ve found blues, reds, ochres … lilies with some gilding and others whose traces are preserved in negative”, chief heritage curator Jonathan Truillet told the daily La Croix.
People walk on the forecourt of Notre Dame’s Cathedral, on May 31st, 2020.
French officials are considering cleaning the inside surfaces of the cathedral with one of the newest technologies in art restoration: lasers. Chicago-based art restoration expert Bartosz Dajnowski invented the technique, which his company, GC Laser Systems, tested inside Notre Dame last month.
The technique uses light to weed out contamination without chemicals or mechanical abrasion, he says. Dajnowski’s lasers have cleaned the facade of the U.S. Supreme Court building and the lions in front of the New York Public Library.
After the big April 2019 fire at Notre Dame the organ was damaged but repairable. A nearly 30-metre-high scaffolding was erected in the summer to enable the organ’s removal.
The keyboard console was the first element to be lifted out in early August, which freed up space so that a work surface could be installed in front of the instrument. Over the past four months, thousands of metal and wooden pipes and box springs have been taken away in four waterproof containers and transported to a warehouse in the Parisian region. All that remains in the cathedral is the sideboard, some bellows and several pipes that are too fragile or difficult to remove and will therefore be cleaned on site.
The symphonic organ has been the voice of Notre Dame since 1733. Its 8,000 pipes divided into 115 stops make it France’s largest instrument in terms of register.
In order to get the Notre Dame restoration elements correct, no effort has been spared in locating the correct materials. In order to stabilize and restore the vault, experts must identify limestone with identical properties as the centuries-old blocks already intricately locked in place.
Geologist Lise Leroux studied the stone to find its origin, leading her to quarries beneath Paris, now commonly known as the Catacombs, where she has been able to match micro-fossils found there with the samples from the vaulting stones in the cathedral.