48 



The plane of the tube -slide is inclined to the axis of the tube at an 

 angle of about 84. The plane of the objective slide, No. 53, is inclined 

 at a corresponding angle so that, on being withdrawn, the objective moves 

 slightly away from the specimen. A screw -- turned by a watch key -- serves 

 as a centring adjustment in the direction of the slide, while an endless screw (at 

 right angles to the first-mentioned and, like it, regulated by a watch key) effects 

 the centring of the objective at right angles to the slide. 



Objectives having their mounts so adjusted as to be approximately in focus 

 when changed can also, by means of the screw-collar on the objective slide, be 

 accurately focused and then permanently fixed in their proper position by a 

 counterscrew-collar. 



We are prepared, at request, to adjust with the greatest care several ob- 

 jectives used on a revolving nose-piece or with sliding objective- changers to one 

 focal plane, with the exception of all Immersion systems and the achromatic 

 Objectives a<j aa, but we must expressly remark that this adjustment 

 is accurate only when the correct tube-length is maintained. 



Tube-slide, No. 52 ... 

 Objective-slides, No. 53, each 



Price: Marks 10. . 

 10. . 



Code-word : Psireja. 

 Parental. 



Fig. 21. 

 Sliding Objective-changer. 



a: tube-slide; b: objective-slide with objective attached; c: intersection. 



(Full Size.) 



