CH. VII] PROJECTION OF IMAGES OF OPAQUE OBJECTS 167 



271. Historical development. See appendix. 



References to literature : See the books referred to in Ch. i, 2, 

 also the special catalogues and directions furnished by the manu- 

 facturers of Opaque Lanterns and combined projection apparatus. 



PROJECTION OF IMAGES OF OPAQUE OBJECTS 

 272. All of the images seen on a white screen within a dark 

 room were originally of opaque objects. These objects were 

 brilliantly illuminated by the sun, and the light reflected from them 



FIG. 89. CAMERA FOR EXHIBITING SURROUNDING LANDSCAPES. 

 (From the Catalogue of McAllister). 



In a kind of cupola at the top is situated a plane mirror and beneath that a 

 projection objective. The cupola rotates, thus enabling the operator to bring 

 any desired scene upon the horizontal screen within the room. Such cameras 

 were once common at fairs and in parks. 



