Make two holes in the wainscot of a room, each a foot high and ten inches wide, and about a foot distant from each other. Let these apertures be about the height of a man’s head, and in each of them place a transparent glass in a frame like a common mirror.

Behind the partition, and directly facing each aperture, place two mirrors inclosed in the wainscot, in an angle of forty-five degrees. These mirrors are each to be eighteen inches square, and all the space between must be inclosed with pasteboard painted black, and well closed that no light can enter; let there be also two curtains to cover them, which you may draw aside at pleasure.

When a person looks into one of these fictitious mirrors, instead of seeing his own face, he will see the object that is in front of the other; thus, if two persons stand at the same time before these mirrors, instead of each seeing himself, they will reciprocally see each other.

There should be a sconce with a lighted candle placed on each side of the two glasses in the wainscot, to enlighten the faces of the persons who look in them, or the experiment will not have so remarkable an effect.