How many visitors to Paris could fail to notice the Sacre Coeur, a whitewashed skeleton on the Montmartre hill in northern Paris? At the highest point in the city, this bleached basilica punctuates the skyline on the horizon.
But why does this church appear so white? Has it been painted with specialist paint? Is there an army of workers perennially scrubbing it to keep it clean?
The answer is truly scientific. The church is made of travertine stone, quarried in Chateau-Landon, France. The stone lets out a chemical called calcite which means that the building stays white even when exposed to the elements.
Perhaps the architect, Paul Abadie, had a view about the problems of pollution in modern cities. Whatever his motive, the use of travertine stone has withstood the test of time. Travertine stone was used by the Romans two millennia earlier to build the Colosseum, the largest building in the world built mainly from this material. Subsequently, it has also been used at the Getty Centre in Los Angeles.
The foundation stone of the Sacre Coeur was laid in 1875 and the funding for this and the remaining stones came from donations from pilgrims. Stones could be “bought”, in the shape of simply a brick, for example, or, more extravagantly, an entire column.
The materials are put together to comprise an unusual Romano-Byzantine structure with distinctive horseshoe arches. To the front, there is a divergence from the use of the characteristic white stone in the use of bronze as the material for equestrian statues of French national saints Louis IX and Joan of Arc.
Consecrated in 1919, the Sacre Coeur, Montmartre, sends a message of Catholic purity to the city of Paris.
