240 SUMMARY OF CURRENT RESEARCHES RELATING TO 
polariser is a condensing system of two lenses, the upper of which can he 
removed for observation in parallel light. For observation of the axial 
Fig. 48. 
image with magnification, the Klein’s lens L is attached to the analyser 
by the three screws. 
The Fuess Microscope, in which the Dick principle for the simul- 
