midnight
_ Unto God be the glory In the Highest ; Peace be on the earth , On the earth , Unto men who have good-will . _ '' So they chanted in their white robes in the Chapel of the Holy Innocents in the Castle of Machecoul near by the Atlantic shore . The chamber of Gilles de Retz testified to the extraordinary advancement of that great man in knowledge which has been claimed as peculiar to much later centuries . The window casements were so arranged that in a moment the place could either be made as dark as midnight or flooded with bright light . The walls were always freshly whitewashed , and the lime was constantly renewed . The stone floor was stained a deep brick red , and that , too , would often be applied freshly during the night . At a time when the very word `` sanitation '' was unknown , Gilles had properly constructed conduits leading from an adjoining apartment to the castle ditch .