I was attracted to the drawing-room by a humming noise; it came from a black enameled affair like an electric motor, just beneath the ceiling. It was moving slowly about the ceiling, dragging something through the room after it; and as I watched I noted that it was covering the room systematically by means of a sort of “traveling-crane” arrangement. The things hanging from the motor were light hoses with expanded endings, and the surprising thing about them was that they moved and curled about this way and that, like an elephant’s trunk or a cat’s tail. They reached here and there, poked into corners, under chairs, and around objects; and I could hear the sound of the suction as their vacuum cleaned up the dust. When the room had all been cleaned, the apparatus receded into an opening in the wall, and hid out of sight.