KIRCHER'S MYSTERIOUS HANDWRITING. 167 



exhibition, the warning written in luminous letters on the 

 wall, or any word associated with the fate of the individual 

 observer, could not fail to produce a singular effect upon 

 his mind. The words might be magnified, diminished, 

 multiplied, coloured, and obliterated, in a cloud of light, 

 from which they might again reappear by the methods 

 already described, as applicable to the magic lantern. 



The art of forming aerial representations was a great 

 desideratum among the opticians of the seventeenth 

 century. Vitellio and others had made many unsuccess- 

 ful attempts to produce such images, and the speculations 

 of Lord Bacon on the subject are too curious to be with- 

 held from the reader. 



" It would be well bolted out," says he, " whether great 

 refractions may not be made upon reflections, as well as 

 upon direct beams. For example, take an empty basin, 

 put an angel or what you will into it ; then go so far from 

 the basin till you cannot see the angel, because it is not 

 in a right line ; then fill the basin with water, and you 

 shall see it out of its place, because of the refraction. 

 To proceed, therefore, put a looking-glass into a basin of 

 water. I suppose you shall not see the image in a right 

 line or at equal angles, but wide. I know not whether 

 this, experiment may not be extended, so as you might see 

 the image and not the glass, which, for beauty and strange- 

 ness, were a fine proof, for then you should see the image 

 like a spirit in the air. As, for example, if there be a 

 cistern or pool of water, you shall place over against it 

 the picture of the devil, or what you will, so as that you 

 do not see the water. Then put a looking-glass in the 

 water ; now if you can see the devil's picture aside, not 

 seeing the water, it would look like the devil indeed. They 

 have an old tale in Oxford, that Friar Bacon walked 

 between two steeples, which, was thought to be done by 

 glasses, when he walked upon the ground." 



