EXPERIMENT WITH A MIRROR. 113 



it, a small doll, for example. Now, so long as the glass 

 and the doll are both upright, the image of the doll in the 

 glass will appear upright, and the table, as reflected in the 

 glass, will appear level, as it is in reality. But the moment 

 that you begin to tip the glass forward, the reflected por- 

 tion of the table will begin to rise up, and the reflected 

 image of the doll will incline forward, and what at first 

 thought seems singular, the apparent movement of what is 

 seen in the mirror upward and forward will be twice as 

 great as that of the mirror itself forward and downward; 

 so that when the mirror is inclined at an angle of forty- 

 five degrees that is, half way down to the table the re 

 fleeted part of the table will be perpendicular, and the doll, 

 instead of standing upright, will be projected forward, as 

 if she were standing on a wall. 



A very good thing to try this experiment with, especial- 

 ly when older brothers or sisters wish to show it to the 

 younger children, is an image of a mouse, and then the 

 mouse will seem, when reflected, as if running up or com- 

 ing down a wall. 



Thus, instead of there being any difficulty in represent- 

 ing the ghosts and goblins as appearing to be on a wall, 

 the real difficulty is to make them appear to be on a level 

 floor. 



There are various means and contrivances used to ac- 

 complish this last purpose, one of which is to have another 

 glass, to reflect the light a second time, and so bring the 

 position right. 



Another is to have the person representing the ghost, or 

 the figure, whatever it is, placed horizontally on the floor, 

 and thus it will appear, when reflected, as if standing back 

 against the wall. You can obtain a general idea how this 

 is done by holding the looking-glass in an inclined position 

 before you on the table, and then placing the doll on its 



