the ordinary stage, of sufficient size to reflect the full length of the actors or objects on the hidden stage to the audience in the pit, boxes, and galleries of the theatre. The hidden stage is between the glass and the audience. The glass may be mounted in a swing frame so that it may be adjusted to the angle required, or it may readily be done by screws or ropes and pulleys, or otherwise. The glass screen is to be set at such an inclination as to bring the reflected image to the level of the visible or ordinary stage. This will enable the spectators, whether in pit, boxes, or gallery, to see the reflected image without any obstruction to the view above the foot-lights, and it will be visible from all parts of the house except those extreme positions which cannot command a view through the glass of that part of the stage where the image is reflected. The proper angle of inclination of the glass is ascertained experimentally by having persons in the different parts of the house to say when the image is shewn to them correctly. The scenery is so disposed as to conceal the frame of the glass, and we prefer that the glass should be able to descend into an opening or box _g_ beneath the stage, in which case we counterbalance the glass and frame so that they may easily be raised into the position desired by means of a rope _h_, by which, aided by the bolts _i_, the glass is supported in the required position. The glass may either be adjusted when screened from the audience, and remain in position during the scene, or (the proper angle of inclination having been previously ascertained by experiment) the glass may be raised on to the ordinary or visible stage, and placed in position whilst the scene is before the eyes of the audience under a subdued light without the movement being observed, for which latter purpose the top bar of the frame of the glass should be made very light or be omitted altogether. This arrangement admits of an actor on the visible stage passing across the space which the glass is to occupy, and this he can do just before the appearance of the phantom, and then immediately the glass is run up, the trap doors are opened, the actor or image on the hidden stage is illuminated and the phantom appears. This arrangement will render it less likely that the audience should imagine that there is anything interposed between them and the actors than if the glass plate remained permanently in position during the scene. The hidden or lower stage may be provided with a well or hole up which an actor can rise; he will then appear as a spectre rising out of the visible stage. The lanterns may be provided with coloured glasses in order to heighten the effect. As the actors on the visible stage do not themselves see the spectral images, marks should be placed on the stage or other indications made in order that they may know the position which the spectres appearing to the audience are to occupy.