SURFACE LAYERS OF CRYSTALS 



15.^ 



Table I 



Summary of Ikformation Coxcerxing tife Nature of the Disturbed Surface 



Material of Quartz Plates 



Fig. 13.— Electron diffraction photographs of a BT quartz plate taken with a 50 kv. 

 electron beam (C. J. Davisson) 



disturbed layer of worked surfaces of quartz, indicating the teclinique 

 through which the information was obtained in each case. In order that 

 this table shall be complete the electron diffraction work of C. J. Davisson 



