Baths of Caracalla, Rome, Italy, approx 212-217, perspective imaginary reconstruction of interior of frigidarium, from Eugène-Emmanuel Viollet-le-Duc, Entretiens sur l'architecture, atlas vol (Paris, 1863), pl 7, collection Canadian Centre for Architecture, Montréal		Baths of Caracalla, Rome, Italy, approx 212-217, cut-away perspective of the roofing structure of the central hall, drawing of 1867 by Viollet-le-Duc, from Eugène-Emmanuel Viollet-le-Duc, Compositions et dessins (Paris, 1884), pl 88