The convent of the Petit-Picpus-Sainte-Antoine filled almost the whole of the vast trapezium which resulted from the intersection of the Rue Polonceau, the Rue Droit-Mur, the Rue Petit-Picpus, and the unused lane, called Rue Aumarais on old plans. These four streets surrounded this trapezium like a moat. The convent was composed of several buildings and a garden. The principal building, taken in its entirety, was a juxtaposition of hybrid constructions which, viewed from a bird’s-eye view, outlined, with considerable exactness, a gibbet laid flat on the ground. The main arm of the gibbet occupied the whole of the fragment of the Rue Droit-Mur comprised between the Rue Petit-Picpus and the Rue Polonceau; the lesser arm was a lofty, gray, severe grated façade which faced the Rue Petit-Picpus; the carriage entrance No.