Using a structural system consisting of cast iron pillars and metal vaulting, Laloux's design was admired for the fact that it was well-integrated and hidden by a stone exterior.  Photo 4 of 13 in Inside the Musee d'Orsay by Tiffany Chu

Inside the Musee d'Orsay

4 of 13

Using a structural system consisting of cast iron pillars and metal vaulting, Laloux's design was admired for the fact that it was well-integrated and hidden by a stone exterior.