 Even the doors linking to the connecting corridors were covered by screens, sometimes disguised as bookcases with dummy books, or just simply covered in the same wallpaper as that with which the room was decorated, as the existence of servants was not to be acknowledged.Cleaning had to be performed in the early hours of the morning while the employers were asleep, and in the grander houses only male servants were allowed to be visible, and then only when required.In some large houses from the beginning of the 19th century, enormous and ingenious efforts of building and design were employed to keep the staff out of sight.