12 SCIOPTICON MANUAL. 



MAONIFIEI* IMAGE. 



This rule works both ways ; for suppose a screen to 

 bo suspended in place of the man, the space being dark- 

 ened, and suppose the three-inch inverted image to bo 

 "fixed" and highly illuminated, then a secondary imago 

 will be projected upon the screen ten feet from the lens, 

 corresponding to the original object in size and position. 



INFERENCE 1. 



A good portrait objective for the camera is also 

 suitable for a lantern objective ; for the lines of light and 

 the angles are in both cases the same. 



INFERENCE 2. 



The light, if reflected from the three-inch picture, 

 radiates so as to cover 100 times as much surface on the 

 magnified image. How, as a very small fraction of this 

 reflected light is re-reflected to the eye of the observer, it 

 seems a hopeless undertaking, to make the opaque lan- 

 tern practically useful in showing the images of small 

 paper photographs, on a large scale, with any ordinary 

 flames, however well arranged. 



INFERENCE 8. 



With an intense light at a point behind the three-inch 

 transparency, converged by a condenser, so as to enter 

 the objective through all points of the picture, the mag- 

 nified image is illuminated with incident rays concentra- 

 ted, and its exhibition becomes a success. 



INFERENCE 4. 



Additional light outside this point (as some recom- 

 mend), would not fall in line with the objective so as to 

 improve the illumination; while the additional heat and 

 diffused light would be very objectionable. 



