Abstracts of Technical Articles From Bell System Sources 



Scattering of Quanta with Diminution of Frequency.^ Karl K. 

 Darrow. In this article the author points out that certain phenomena 

 of X-rays recently reported were illustrations of the general process 

 of scattering of light with change in frequency, which had just begun 

 to attract attention owing to important observations made by Raman 

 and others with visible and ultra-violet light. The content was 

 amplified and restated in Dr. Darrow's article entitled "Contemporary 

 Advances in Physics, XVII — The Scattering of Light with Change 

 of Frequency," which appeared in the January, 1929, issue of the 

 Bell System Technical Journal. 



Dissociation of Molecules as Disclosed by Band-Spectra.'^ Karl K. 

 Darrow. This lecture was a contribution to a Symposium on 

 Atomic Structure of the American Chemical Society. It is an ele- 

 mentary account of the way in which the band-spectra of molecular 

 gases are interpreted so as to disclose the laws and details of the 

 dissociation of their molecules into atoms, a process of great scientific 

 and some practical importance. 



Using Inspection Data to Control Quality.^ H. F. Dodge. This 

 paper outlines a method of using inspection data to improve the 

 technique of controlling at economic levels the quality of product in 

 the various stages of manufacture. Essentially, the method rests on 

 the application of statistical methods of analysis, employing the 

 viewpoint that every batch of manufactured product constitutes a 

 sample from a much larger universe and as such is subject to random 

 of chance variations in quality. The variations in quality as observed 

 in inspection data may thus be the result of either chance causes or 

 of fundamental production causes whose presence is undesirable. 



Speech and Hearing.'^ Harvey Fletcher. This book is concerned 

 mainly with the results of Bell System research work on speech and 

 hearing. These results, however, can be understood and appreciated 

 better when their relationship to similar work is shown. Conse- 



1 Science, Vol. 68, November 16, 1928, pp. 488-490. 

 ^ Chemical Reviews, Vol. V, December, 1928, pp. 451-466. 



^ Manufacturing Industries, Volume XVI, November, 1928, pp. 517-519, and 

 December, 1928, pp. 613-615. 



* D. Van Nostrand Co., Inc., New York, 1929. 



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