Labrouste’s Bibliothèque Nationale is a prime example of how the introduction of new building materials (such as iron) influenced the change in principles. The materials offered a new balance between elegance and functionality. The building itself contains the ionic order, specifically since it is for a place of wisdom. One can also take notice of the barrel-vaults and other intricate metal arches, which was inspired from a train station. Additionally, there is an oculus in each dome, providing a characteristic of an Oeil-de-Boeuf.