110 ANNUAL OF SCIENTIFIC DISCOVERY. 



In ghost-making, a plate of clear glass is placed between the observers 

 and where the ghost is made to appear ; and what is seen as the ghost is 

 nothing more than the feeble image of a true object, produced by re- 

 flection from the surface of the plate. But the ghost, when well shown, 

 is an intensely vivid image, the very reverse of feeble ; and the question 

 is, How is the intensification of an originally feeble image effected ? It 

 is effected by greatly reducing or extinguishing all other lights, and by 

 concentrating an intense light on the original object, and thus greatly 

 increasing the reflecting power of the clear glass plate, and by at the 

 same time forming a dark background behind the plate, which further 

 assists in throwing out the image or ghost to the eye of the spectator. 

 All this is quite a common occurrence in the shop-windows along the 

 streets, and perhaps still better shown in a lighted railway-carriage at 

 night. The ghosts of the passengers in the carriage are shown through 

 the carriage windows upon the apparent ground of the dark sky, and 

 the carriage lamp, from its being the most luminous object, presents the 

 most vivid ghost of all. 



As applied to theatrical performances the arrangements for the repre- 

 sentation of a ghost are substantially as follows : Upon the stage of 

 the theatre is placed a large plate of glass, inclined at an angle toward 

 the person or object that is to be "ghostified." The audience does not 

 always perceive this, because the stage is darkened, and because objects 

 behind the glass may be seen through it. In front of this glass is a 

 large trap, opening beneath the stage, and forming a square enclosure ; 

 this is lined with black cloth. The person whose ghost is to be repre- 

 sented stands in a sloping position against the back of this place, and a 

 strong light is thrown upon his figure from a j lamp placed opposite. 

 Now the image of the object is reflected from the glass plate to tho 

 audience, and this image is seen by them to be as far behind the plate 

 as the true object is placed in advance of it. The light used to illumi- 

 nate the person should be very powerful, as the " lime," or Drummond 

 light, though a good argand burner with a reflector will answer. The 

 ghost is seen to be illuminated from below up, and this conies of placing 

 the lamp low and throwing the light on the true object upwards. A 

 white, lustrous dress given to a female personating the ghost exalts the 

 effect. 



All the room-lights are in the mean time reduced, otherwise the audi- 

 ence also, as in the case of the passengers in the railway-carriage, would 

 be converted into ghosts. As much light, and no more, is left on the 

 stage as admits of the actors on it being seen. These performers see 

 no ghost ; all their movements are calculated as to place and time. 

 The ghost placed on the stage, so far as the adaptations of this illusion 

 have yet gone, is fixed ; a hand or part of the body may be moved, but 

 not the whole, beyond a very small distance. 



Ghost-making, according to the above device of Prof. Pepper, can 

 be applied for social, as well as theatrical entertainment, and the sim- 

 plicity of the apparatus employed for the production of the many illu- 

 sions of which this arrangement is capable will doubtless henceforth 

 furnish a fruitful source of amusement. 



The introduction in London of the above-described optical arrange- 

 ment into theatrical performances, for the production of ghostly images, 

 gave rise to a lawsuit of an interesting character. The device in question 



