156 BELL SYSTEM TECHNICAL JOURNAL 



to the truth. The method is a combination of analytical and graphical 

 analysis applied to several hypothetical solid solution crystals each 

 containing more than a thousand atoms. It may also, as is pointed 

 out in the paper, be used in problems concerning other than magnetic 

 properties of solid solutions. 



The SJwrt Wave Limit of Vacuum Tube Oscillators.^ C. R. Englund. 

 A study of the shortest attainable undamped waves which can be 

 produced with vacuum tube oscillators resulted in the production of 

 one-meter waves as the fundamental mode of oscillation of the circuit. 

 The shortest waves "attainable with reasonable ease" with several 

 types of standard tube are found to be: 



Tube Meters 



W. E. 230-D (60 mil. fil.) 2.0 



" 205-D C'E" 5-watt) 3.2 



" 221-D (l/4amp. fil.) i.i 



" 211-D C'G" 5-watt) 3.5 



In order to reduce the capacity as far as possible some experiments 

 were made with unbased tubes. A special 5-watt tube produced four- 

 meter signals which were received up to one-mile distances. An 

 interesting feature of the work was the interference caused by the 

 presence of the observer while conducting the experiments, because of 

 the action of the human body as a tuned antenna at these wave- 

 lengths. 



A General Theory of the Correlation of Time Series of Statistics^ 

 M. K. ZiNN. In mathematical physics elaborate methods have been 

 devised for dealing with oscillatory systems, damped or undamped, 

 like pendulums, vibrating strings, vibrating telephone diaphragms, and 

 with systems that are essentially damped but have no oscillatory 

 characteristics, like the flow of heat and diffusion. The writer of this 

 article approaches the problem of the economic structure with a point 

 of view which sees the business world as behaving like such an oscil- 

 latory system. 



The structure of economic society is a system exhibiting certain 

 structural factors which express the tensions that are set up by a 

 shift in prices here on some other factor like employment there. The 

 problem is : How are these tensions to be inferred from statistics which 

 describe the observed behavior of the economic world ? The economist, 

 unfortunately, cannot disconnect, say, the Federal Reserve system 

 from the rest of the economic structure, connect it to a portable test 



«Prof. /. R. E., 15, 914, November, 1927. 



' The Review of Economic Stalislics, Harvard luonomic Service, 9, 184 (1927). 



