676 



OPTIC PROJECTION 



Projection instruments of the third class can be properly divided into three 

 groups: i, the Magic Lantern; 2, the Projection Microscope, and 3, the 

 Moving Picture Machine. 



1. The Magic Lantern 



It is not certainly known who first produced a workable magic lantern. 

 The first figure and description we have found is the one of a Danish mathe- 

 matician (Walgensten). The figure and description occur in the mathematical 

 treatise of Milliet de Chales (1674), where it states that "in the year 1665 there 

 came to Lyons a learned Dane well versed in dioptrics. Among other things 

 he exhibited a magic lantern. . . In the first place the greater the distance 



eamcTcaeijaamanimumadje^fcnbendis iis inventiones Lucernamfc 

 termt, Quos mier primus fu,t Thomas 7 s 71 a nob.s dcfcnptam . in meliorcni 

 waieenttenius Danus , haud mfimz notz formara reduxit, quam &pofteamaeno 

 Mathemaucus , qoi rccolcns mcas m dc- ; fuo lucro dircrfis in Italia prmcipibosvcn- 



FIG. 404. THE MAGIC LANTERN OF KIRCHER. ' Its 



(From the Ars Lucis et Umbrae, 1671, p. 768) 



The lamp is a naked flame with a concave reflector behind it. The lantern 

 slide is a long strip with many pictures which can be shown one after the other. 

 The lantern slide appears at the wrong end of the projection objective, 

 making it difficult to see how any image could be projected. At the bottom 

 of the picture is a part of the text in which the better form of Walgensten 's 

 lantern is conceded. 



