

FOREWORD TO THE FIRST BRITISH EDITION 



THIS monograph is an amplified version of a lecture, 

 delivered on the 4th of March, 1943, before the Cambridge 

 University Physics Society. In its present form it intends 

 to be both an introduction to the electron microscope and a 

 critical contribution to its theory. There is no doubt that in the 

 near future this new instrument will be used by thousands of 

 medical, biological, and chemical workers who have no theoreti- 

 cal acquaintance with electronics. It may be hoped that the 

 fundamentals of electron optics which are briefly explained in 

 Chapters 2 and 3 will enable them to understand the basic opera- 

 tion of the instruments described in Chapters 4 to 11. The last 

 chapters, 12 to 14, are of a more advanced character, and are 

 addressed in the first place to physicists and electronic engineers. 

 An appendix on the diffraction theory of the microscope has 

 been added for the benefit of those who are no optical specialists. 

 At the present stage of electron microscopy, it was not possible 

 to include more than a cursory survey of the applications of the 

 new instrument, and little more than a hint at laboratory 

 technique which is growing so fast that any review of it would 

 be obsolete by the time it is printed. However, the fundamental 

 development of the instrument has now reached a stage beyond 

 which progress is likely to be slow and difficult. At this point, 

 it seemed appropriate to look into the future, and to try to 

 explore in imagination the avenues of further development. As 

 this is a proverbially risky undertaking, the author is juite 

 prepared to join the ranks of other, more illustrious, prophets 

 who have failed. 



For permission to reproduce illustrations, the author wishes 

 to thank the owners of the following journals: Journal of Ap- 

 plied Physics, RCA Reviezv, Electronic Engineering, Proceed- 

 ings of the Institute of Radio Engineers, Proceedings of the 



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