604 BELL SYSTEM TECHNICAL JOURNAL 



experimental data described here were obtained, we could have learned 

 a great deal more concerning gas upon our crystal surface with com- 

 paratively little effort. In the above pages there are many suggested 

 continuations which were not followed up. When our measurements 

 were made our interests were quite naturally centered upon the 

 phenomenon that electrons are diffracted, and we neglected many lines 

 of physical investigation which were open to us. The work described 

 here must be regarded as only the very first application of what may 

 possibly develop into a useful method of crystal analysis, occupying a 

 field entirely distinct from the field of X-ray analysis. 



