Labrouste’s Bibliothèque Nationale is an important example of architecture built during the First Industrial Revolution, and combines elements of Antiquity with modern material and techniques. The columns are inspired by the Greek Ionic Order (which represents wisdom, fitting for a library), but the arches connected to them are made from modern cast iron, which allowed for a lighter, thinner appearance. The windows are arcuated like Roman styles, but feature larger windows that let in more light. Although domes were used previously, these modern domes used terracotta instead of heavy, bulky stone, and each featured an oculi.