ABSTRACTS OF TECHNICAL ARTICLES 535 



to 16 per cent vanadium were investigated with the result that permanent 

 magnet materials of unusual mechanical as well as magnetic properties were 

 discovered. The alloys differ from most age-hardening alloys in that the 

 gamma phase, stable at high temperatures, is dispersed in the alpha phase, 

 stable at low temperatures, instead of vice versa. 



Distribution of Sample Arrangements for Runs Up and Doum?^ P. S. 

 Olmste.ad. Using the notation of Levene and Wolfowitz, a new recur- 

 sion formula is used to give the exact distribution of arrangements of n num- 

 bers, no two alike, with runs up or down of length p or more. These are 

 tabled for n and p through n = 14. An exact solution is given for p > n/2. 

 The average and variance determined by Levene and Wolfowitz are pre- 

 sented in a simplified form. The fraction of arrangements of n numbers 

 with runs of length p or more are presented for the exact distributions, 

 for the limiting Poisson Exponential, and for an extrapolation from the 

 exact distributions. Agreement among the tables is discussed. 



Radar Systems Considerations}^ D. A. Quarles. In the broad field of 

 radio technology, radar (object location) systems have come to occupy a 

 relatively new but highly specialized area. Because radar is a seeing and 

 measuring art, it has put a special premium on short wavelength and has 

 thus tended to accelerate greatly the already rapid trend toward higher 

 frequencies. Moreover, many radar systems are associated with computer 

 and serv'o mechanisms for automatic control purpose such as gunfire, bomb 

 release and the like. To meet these new needs, a dozen or more highly 

 developed fields of specialization covering such components as antennas, 

 pulse transmitters and display devices have been created. Planning a new 

 radar system calls for an appraisal of these component arts and for selection 

 and balancing of component characteristics to produce an integrated 

 system. The present paper deals with such technical considerations in- 

 volved in planning an overall radar system as a background for other more 

 detailed technical expositions of the component arts. 



The Effect of Rain upon the Propagation of Wares in the 1- and 3-Centimeter 

 Regions}" Si.oax 1). Robertson and Archie P. King. This paper 

 presents some experimental results which show the effect of rain upon 

 the transmission of electromagnetic waves in the region between 1 and 4 

 centimeters. 



At a wavelength of 1.09 centimeters, the waves are appreciably attenuated, 



^^ Annals of Mathematical Statistics, March 1946. 

 ^^Elec. Engg., Trans. Sec, .\pril 1946. 

 «Proc. /./?.£., April 1946. 



