ABSTRACTS OF TECHNICAL ARTICLES 215 



tal time axis so that speech over an interval of a second or more is always 

 visible. The upper portion of the screen portrays a spectrum analysis and 

 the lower portion a pitch analysis of the speech sounds. The frequency 

 band up to 3500 cycles is divided into 12 contiguous sub-bands by filters. 

 The average speech energy in the sub-bands is scanned and made to control 

 the excitation of the screen by the electron beam which is swept synchro- 

 nously across the screen in the vertical direction. A pitch analyzer pro- 

 duces a d-c. voltage proportional to the instantaneous fundamental fre- 

 quency of the speech and this controls the width of a band of luminescence 

 that the electron beam produces in the lower part of the screen. The 

 translator had been used in a training program to study the readability 

 of visible speech patterns. 



Derivatives of Composite Functions.^ John Riordan. The object of 

 this note is to show the relation of the Y polynomials of E. T. Bell, first to 

 the formula of DiBruno for the wth derivative of a function of a function, 

 then to the more general case of a function of many functions. The sub- 

 ject belongs to the algebra of analysis in the sense of Menger; all that is 

 asked is the relation of the derivative of the composite function to the 

 derivatives of its component functions when they exist and no questions of 

 analysis are examined. 



The Portrayal of Visible Speech.^ J. C. Steinberg and N. R. French. 

 This paper discusses the objectives and requirements in the protrayal of 

 visible patterns of speech from the viewpoint of their effects on the legibility 

 of the patterns. The portrayal involves an intensity-frequency-time analy- 

 sis of speech and the display of the results of the analysis to the eye. 

 Procedures for accomplishing this are discussed in relation to information 

 on the reading of print and on the characteristics of speech and its inter- 

 pretation by the ear. Also methods of evaluating the legibility of the 

 visible patterns are described. 



Short Survey of Japanese Radar — 1}° Roger I. Wilkinson. The 

 result of a study made immediately following the fall of Japan and recently 

 made available for public information, this two-part report is designed to 

 present a quick over-all evaluation of Japanese radar, its history and de- 

 velopment. As the Japanese army and navy developed their radar equip- 

 ment independently of each other, Part I of this article concentrates on the 

 army's contributions. 



*Amer. Math. Soc. Bulletin, August 1946. 

 ^ Jour. Aeons. Soc. Amer., July 1946. 

 ^"Elec. Engg., Aug.-Sept. 1946. 



