80 



The Electron Microscope 



neath the stenographer's desk on which the unit is mounted, but 

 on a separate base. 



The power supphes have been also very considerably sim- 

 plified. Whereas the principle of high frequency rectification and 

 inverse feedback regulation has been retained, the number of 

 valves has been reduced to eleven. The accelerating potential is 

 30 kv in the small model against 60 kv in the large microscope, 

 and its fluctuation is about 0.015 per cent against 0.004 per cent 

 or less. 



Specimen Chamber 



Viewing Screen 



A Complete Unit 

 moved wherever required 



Supply, and 

 Electrical Circuits 

 in Desk 



Fig. 26. R.C.A. Type EMC Electron Microscope (Console Model) 

 Essentially as described in connection with fig. 23 



The resolution of the small experimental model is not stated 

 by its authors, but it can be judged from figure 24 which shows 

 a membrane spattered with heavy metal particles. The instru- 



