ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



327 



With this projection apparatus all powers of Microscope objectives 

 may be employed, including the -jV oil-immersion. The picture, even 

 when the highest powers are used and the screen is at a distance of 

 12 feet from the apparatus, is of sufficient clearness and brightness to 

 be available for demonstration to a large audience. 



For lantern-slide projection the objective-stage and objective-carrier 

 are swung out of tbe way by means of specially provided joints (fig. 52), 

 and a special projection lens of 300 mm. focal distance is screwed into 

 the diaphragm-holder and a slide-carrier inserted into the bellows- 

 frame. When so arranged the projection can be made upon a screen 

 30 feet distant, over the heads of the audience. 



Liesegang's Universal Projection Apparatus.* — The inventor claims 

 that his apparatus is unique of its kind. It is intended, firstly, for the 

 direct projection of lantern pictures ; secondly, for vertical projection ; 

 thirdly, for the projection of opaque objects ; fourthly, for tho projection 



Fig. 53. 



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of physical phenomena by means of parallel light ; fifthly, for micro- 

 scopic and polariscopic projection ; and finally, for cinematographic 

 projection. 



The apparatus consists of a box, which serves for the reception of 



* Central. Zeit. f. Optik u. Mech., 1900, pp. 222-C (8 figs.). 



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