350 BELL SYSTEM TECHNICAL JOURNAL 



Applications of X -Ray Photography in Industrial Developrtient Work} 

 J. R. TowNSEND and L. E. Abbott.^ The fundamentals of X-ray 

 technic as applied in developmental work of the telephone industry 

 are outlined. A brief description is presented of the physics of X-rays, 

 of the methods used to produce usable X-ray radiation, and of a 

 typical industrial X-ray laboratory. Results are given of investiga- 

 tions at the Bell Telephone Laboratories to determine the sensitivity 

 of X-ray methods of revealing internal defects in metals. Numerous 

 examples illustrating the application of X-rays in telephone work are 

 included, as well as a description of the use of gamma rays for in- 

 dustrial application. 



Principles of Measurements of Room Acoustics} E. C. Wente. 

 The acoustic characteristics of a room can in great part be evaluated 

 from a knowledge of the rate with which sound in the room dies down 

 when emission from the source ceases. The physical principles under- 

 lying the relationship are briefly discussed. It is shown by specific 

 examples that w^e can obtain valuable additional information about 

 acoustics of a room by recording the sound level at one or more points 

 in the room when the frequency of the sound is continuously varied. 



Visual Accompaniment} R. Wolf. The principles of producing 

 "Visual Accompaniments" to musical renditions for the theater are 

 briefly described, as follows: (1) natural scenes for portraying the 

 "musical mood" of the musical composition; (2) the changing and 

 blending of beautiful paintings to interpret the mood, known as the 

 Savage Method; and (3) the use of abstract color forms as a means of 

 interpretation. The technic followed in applying the two latter 

 methods is described in detail. 



3 Presented at the Fall 1934 mtg. of S. M. P. E., New York, N. Y.; published in 

 somewhat condensed form in Metal Progress, February, 1936, under the title "Some 

 Applications of X-Rays to Industrial Problems." 



* Jour. S. M. P. E., February, 1936. 



5 Jour. S. M. P. £., February, 1936. 



