the subject of apparitions, and the latter thought that he would at any rate surprise his strong-minded friend by an easy trick or two. He consequently chose as his confederate a lady to whom the gentleman had been paying great attention during the time of his visit. Robertson one evening mysteriously delivered a small box to him, which he was to place upon his toilet table, and unlock exactly at midnight. The gentleman did so, and what was his astonishment to see the face of the lady with whose charms he had been so deeply impressed suddenly spring out of the box. His look of terror and surprise was evidently too much for Robertson's confederate, who burst into a merry peal of laughter, leaving her admirer in a very disconcerted state.
After all we have said on the subject of mirrors, it is not difficult to guess how this trick was performed. The box in question was painted black on the inside, and contained a concave mirror placed at an angle of 45°. The reflection of the lady, who was of course in the next room, was carried by means of several plane mirrors placed in boxes communicating with each other through the partition of the room, the head of the lady only being strongly illuminated, the rest of her figure not appearing by being kept quite dark.
The figures reflected from smoke are extremely surprising. To perform such experiments a phantasmagoria is necessary. The focus is so adjusted that the distant image falls just above a brasier containing lighted charcoal. Everything being ready, a few grains of olibanum or other gum are thrown on the coals, and the smoke that rises immediately affords a screen for the reflection of the images proceeding from the phantasmagoria. If the amateur is not the possessor of a magic lantern, a properly arranged concave mirror will answer almost the same purpose.
