180 TRANSACTIONS OF SCIENTIFIC SECTION. 



This effect is produced mechanically by a triple 

 optical lantern in such a way that the three projected 

 pictures exactly coincide upon the screen. 



The lantern front used for these new projections con- 

 sists of three prisms converging light from a single con- 

 denser, and radient to three small projectory lenses ; the 

 necessary color screens being located just behind the 

 objectives, (so after all mechanical). 



Various improvements have been made from time to 

 time, the chief of which has been the construction of a 

 camera by which the three negatives representing the 

 effect of the object photographed upon the three funda- 

 mental color sensations, may be made from one point of 

 view by a simultaneous and equal exposure upon a 

 single sensitive plate. 



The value of Ives discovery, from a practical point of 

 view, is yet to be determined. From a purely scientific 

 standpoint, his process cannot be compared with that of 

 Lippman. Of both it may be said that they will be sure 

 to stimulate further investigation, and he is a rash man 

 who will positively assert that out of such investigations 

 a simple practical process of reproducing the colors of 

 Nature in a photographic image may not be evolved. 



The subject was further discussed by LeRoy C. 

 Cooley, Ph. D., who strongly endorsed the scientific 

 character of Lippman' s experiments and predicted that 

 final success would come along that line, if at all. 



APRIL 5, 1892— NINTH REGULAR MEETING. 



Present Chairman Burgess, and Members Elting, 

 Gardner, Sutcliffe, Van Gieson, Neumann, Winne, C. N. 

 Arnold and visitors. Rev. A. H. Huizinga of New 

 Paltz, N. Y., read avery interesting paper on " Assyri- 

 ology." 



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