6 BELL SYSTEM TECHNICAL JOURNAL 



presented themselves in the mechanical construction of large tubes 

 in which vacuum tight joints must be made and maintained between 

 glass and large masses of metal. The importance of the problem, 

 however, was such that Stoekle and Buckley pushed on in the face of 

 difficulties to the construction of tubes which could handle kilowatts 

 where previous tubes could only handle watts. 



A step in the direction of overcoming these difficulties was made by 

 Messrs. Schwerin and Weinhart, who were working with Dr. Buckley 

 on the problem, and who suggested that the anode might be made 

 in the form of a tube or thimble of platinum sealed into a glass vessel 

 and kept cool by passing water through it. 



Fig. 1 



This suggestion led to the development of a tube which, although 

 not the one finally adopted, is discussed in some detail since it was the 

 first one to be pushed to such a point as to give promise of economical 

 commefcial manufacture. 



