1 84 PROJECTION OF IMAGES OF OPAQUE OBJECTS [Ca. VII 



FIG. 100. HOME BALOPTICON FOR OPAQUE OBJECTS. 



(Cut loaned, by the Bausch & Lomb Optical Co.). 



In this instrument there is used a small arc light for attachment to the house 

 lighting system. The rheostat is shown at the left. 



The object is horizontal and the lamp shines in part directly upon the object 

 and in part the light is reflected upon the object by a mirror. From the object 

 light is reflected to a mirror above the arc light, and from the mirror directed 

 out through the objective to the screen. The projected mirror image appears 

 erect on the screen. 



FIG. 101. HOME BALOPTICON FOR LANTERN SLIDES AND 

 OPAQUE OBJECTS. 



(Cut loaned by the Bausch & Lomb Optical Co.). 



opaque projection is precisely as in fig. 100. For lantern-slide projec- 

 tion the mirror in front of the arc lamp is turned up out of the way and the 

 light passes on to the condenser, lantern slide and objective as in ordinary 

 lantern-slide projection (fig. i). 



