The room for the exhibition ought to be large, and of an oblong shape.
At one end of it suspend a large sheet so as to cover the whole of the
wall. The company being all seated, darken the room, and placing the
lantern with its tube in the direction of the sheet, introduce one
of the slides into the slit, taking care to invert the figures; then
adjust the focus of the glasses in the tube by drawing it in or out as
required, and a perfect representation of the object will appear.