256 



PROJECTION MICROSCOPE 



\_CH. IX 



The water bath should be free from the condenser mounting so 

 that it may not be heated by conduction (see § 413 for special cooler). 





Fig. 207. 



Fig. 207. Leitz Large Micro-Projection Apparatus {Leitz Catalog). 

 In this figure the apparatus is in position for projection with a projection 

 ocular. As here shown it consists of : — 



(/) An arc lamp designed for a current up to 20 amperes ; 



(2) A lamp condenser of three lenses, the two inner ones being adjustable ; 



(3 ) A large water bath for removing the heat ; 



(4) Bellows. At one end is a space for the insertion of ordinary lantern 

 slides {see the next figure) and at the other end are three condensers of different' 



foci on a revolving nose-piece ; 



(5) Objective stage with a special cooler (Zoih's % 413), and a special slide 

 carrier serving as a kind of mechanical stage. 



(6) An objective carrier. This contains a triple, revolving nose-piece at the 

 end of the large tube. This tube contains an iris diaphragm and receives an 

 adapter for the use of projection oculars. For low objectives and when the projec- 

 tion ocular is not to be used, this adapter is removed. Fine and coarse adjustments 

 are present for focusing . 



Each part is mdependent and capable of special adjustment. {As shown in the 

 next figure, the microscope part may be turned aside, leaving the apparatus for 

 ordinary lantern slide projection.) 



§ 412. Special Achromatic Condenser for High Powers. — 

 For objectives of 8 mm. and higher there should be a special achro- 

 matic condenser next the stage for holding the specimens. This should. 



