Saving grace – Science Magazine

Summary

On 15 April 2019, an electrical short was the likely spark for a blaze that threatened to burn the 850-year-old Notre Dame cathedral to the ground. The fire melted the cathedral’s roof and sent its spire crashing through the vaulted stone ceiling. More than 200 tons of toxic lead from the roof and spire was unaccounted for. And the damage threatened the delicate balance of forces between the vault and the cathedral’s flying buttresses: The entire building teetered on possible collapse.At the Historical Monuments Research Laboratory, tasked with conserving all of France’s monuments, a few dozen scientists apply techniques from geology to metallurgy as they evaluate the condition of Notre Dame’s stone, mortar, glass, paint, and metal. They lead the critical work of deciding how to salvage materials and stitch the cathedral back together. And even as they try to reclaim what was lost, they and others are also taking advantage of a rare scientific opportunity. The cathedral, laid bare to inspection by the fire, is yielding clues to the mysteries of its medieval past.