The Maternité de Paris, Port-Royal was the "lying-in" hospital for the poor women of Paris. The obstetrician Stéphane Tarnier pioneered use of incubators for premature infants at the Maternité at the end of the 19th century. The Port Royal abbey (Cistercian order, 1625) close to the Luxembourg Gardens, was transformed into a prison during the French Revolution (also called Prison de La Bourbe and Port-Libre). In 1814, the prison was converted into a maternity hospital, and was fully completed in 1818. The Paris School of Midwives moved in 1794 from the Hotel Dieu (where it had been since 1610) to Port Royal. The cloister, chapel and the oratory where the Jesuits and Jansenists debated survive from the old abbey. Le Pautre built the chapel in 1646-1653.