ABSTRACTS OF TECHNICAL ARTICLES 163 



General Formulas for "T"- and "11"- Network Equivalents.^ Myril B. 

 Reed. This paper presents the development of two sets of general formulas 

 which determine a set of "T" or "n" impedances equivalent to any linear, 

 lumped-constant, four-terminal network. 



Concerning Hall'n's Integral Equation for Cylindrical Antennas}'^ S. A. 

 ScHELKUXOFF. The main purpose of this paper is to explain the substantial 

 quantitative discrepancy between Hallen's formula for the impedance of 

 cylindrical antennas, and ours. Hallen's first approximation involves a 

 tacit assumption that the antenna is short compared with the wavelength. 

 Since the subsequent approximations depend on the first, they are degraded 

 by this initial assumption. 



The approximations involved in his integral equation itself are justified; 

 and, if properly handled, the equation yields result-s in much better agree- 

 ment with ours. The last section of the paper is devoted to infinitely long 

 antennas. Such antennas can be treated by at least three very different 

 methods and a comparison is instructive. In practice, the solution for this 

 case is an approximation to a long antenna designed to carry progressive 

 waves. 



Principal and Complementary Waves in Antennas. '^^ S. A. Schelkunoff. 

 In response to an increased interest in mathematical aspects of antenna 

 theor}', this paper presents details of aralysis of cylindrical and other non- 

 conical antennas as a supplement to a previous paper containing the outline 

 of the method and the main results. In the course of the present discussion 

 the theory of principal waves on cylindrical conductors is extended to include 

 the case in which the diameter is not small compared with the wavelength. 



Research Revolutionizes Materials.'^'' J. R. Townsexd. A technological 

 lesson to be drawn from defeated Germany is that whereas Germans had 

 been noted for their fundamental contributions to science, they were unable 

 to compete with the United Nations in the field of applied science and 

 particularly in high-speed production methods. Their defeat was due more 

 to the overwhelming number than to the individual superiority of the arms 

 brought against then. The miracle of American production is based on a 

 design related to obtaining the most from the process used, materials of 

 uniform quality, and high-speed production methods using high-power 

 automatic machinery. Germany's failure was due to standardizing too 

 early and too inflexibly and this meant that they could not compete with the 

 steady improvements in the art. The usual procedure is the development 

 of methods of test followed by collection of data and the formulation of 

 specific requirements controlling the useful quality of the material. Modern 



^Proc. I. R. E., December, 1945. 

 ^oProc. I. R. E., December, 1945. 

 ^^Proc. I. R. E., (anuary, 1946. 

 ^A.S.T.M. Bulletin, December, 1945. 



