Abstracts of Bell System Technical Papers Not 

 Appearing in this Journal 



A Note on the Thermionic Work Function of Tungsten} C. Davisson 

 and L. H. Germer. It has been pointed out that the authors in a 

 previous paper - had neglected to apply a correction for the "Schottky 

 Effect" to their results. The present note applies this correction 

 which is found to be comparatively small and does not materially 

 affect the results given before. A fuller discussion of the interpretation 

 of the work function measurements previously reported is also in- 

 cluded in this note. 



The Action of Fluxes in Soft Soldering and a New Class of Fluxes 

 for Soft Soldering} R. S. Dean and R. V. Wilson. This is a report 

 of basic studies of soldering fluxes undertaken by the authors. It was 

 found that the fluxing action depends on the evolution at soldering 

 temperatures of HCl gas or other halogen acid gases which have been 

 found to be effective soldering fluxes. Based on this discovery 

 soldering fluxes have been found among the organic compounds and 

 the way opened for the development of a truly non-corrosive flux. 



Certain Topics in Telegraph Transmission Theory} H. Nyquist. 

 The author gives results of theoretical studies of telegraph systems 

 which have been made from time to time. Among other things he 

 points out that although the usual method of determining the dis- 

 tortion of telegraph signals is to calculate the transients of the system 

 an alternative method is based on the steady state characteristics. 

 For the first method the telegraph wave is taken as a function of t and 

 for the second as a function of co. A discussion of the minimum 

 frequency range required for transmission at a given signaling speed 

 is also included in the paper. 



Experiments and Observations Concerning the Ionized Regions of the 

 Atmosphere} R. A. Heising. Experiments are described in which a 

 virtual height of the reflecting ionized region was measured using 

 time lag between radio signals arriving over a direct and the reflected 

 path. Heights were found of 150 to 400 miles with vertical move- 



^Phys. Rev., Vol. 30, pp. 634-638, Nov. 1927. 

 2 Davisson and Germer, Phys. Rev., Vol. 20, 300 (1922). 

 ^ Indus, and Eng. Chemistry, Vol. 19, No. 12, pp. 1312-1314. 



4 Presented, A. I. E. E., February 13-17, 1928. A. I. E. E. Jour., Vol. XLVII, 

 No. 3, pp. 214-216, Mar. 1928. 



^Proc. I. R. E., Vol. 16, pp. 75-99, Jan. 1928. 



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