CTLINDEICAL MiKEOBS. 91 



The words might be magnified, diminished, mul- 

 tiplied, coloured, and obliterated, in a cloud of 

 light, from which they might again re-appear 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 

 17th century. Vitellio and others had made 

 many unsuccessful attempts to produce such 

 images, and the speculations of Lord Bacon on 

 the subject are too curious to be withheld from 

 the reader. 



" It would be well bolted out," says he, "whe- 

 ther great refractions may not be made upon 

 reflexions, 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 look- 

 ing-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 strangeness, 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, 



