ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



383 



diapositive 20-30 ; and for episcopic projection 20-50 amperes. In 

 the two latter cases the size of the lecture-hall must be considered. 



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 6 



Zeiss' Projection Apparatus. — Figs. 92-95 are some of the dia- 

 grams of the complete arrangement ; fig. 91 being a sectional elevation, 

 and the others plans. The lettering is the same throughout. A, the 

 water-chamber ; B, illuminating mirror ; D, lantern-slide carrier ; 

 F, horizontal push footplate ; K, coupling screw ; L, projection lamp ; 

 M k, Microscope ; P, projection-system carrier ; r, tube-mirror ; S' two- 

 lens portion of collective lens ; S, single-lens portion of collective lens ; 



