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BELL SYSTEM TECHNICAL JOURNAL 



ments. In the second row of Table 2 the equivalent layers of caesium 

 are computed as upon a smooth cathode surface. To obtain actual 

 layers upon the roughened cathode these values must be divided by a 

 factor which we have judged to be approximately four. In addition, 

 since the oxygen flowed freely into the whole structure of the cell, 



Fig. 7 — Cell design for the deposition of caesium on a cathode surface. 



we must consider a film (probably monatomic) of free caesium adsorbed 

 on the inner surface of the glass bulb which has about four times the 

 area of the cathode. This film must be present since the bulb itself 

 is appreciably photosensitive. In cell A the oxygen, calculated as 



A 



