Supermicroscopes 39 



time in a high voltage electron microscope. C. H. Bachman and 

 S. Ramo,^^' ^^ in the Schenectady laboratory of the General 

 Electric Company, constructed, in 1942, the first commercial 

 electrostatic microscope on this basis. The great advantage of 

 microscopes of this type is that they can entirely dispense with 

 the elaborate voltage and current stabilizers which are indis- 

 pensable in the case of the magnetic type. 



In spite of this advantage, the electrostatic microscope has not 

 been able to catch up with the achievements of the other type. 

 The position appears to be similar to that of the cathode ray 

 tube in television ; the magnetic cathode ray tube threw^ almost 

 the whole burden on the circuit designer, but the circuit engineer 

 was equal to the task. The electrostatic cathode ray tube, how- 

 ever, in which circuit complications were avoided at the cost of 

 complications in the electron-optical system, ^vas less successful. 

 Some of the reasons are discussed in a survey of electron optics 

 by the author.^^ 



