ABSTRACTS OF TECHNICAL ARTICLES 477 



Another phase of radio with automobiles is the use of Ijroadcast 

 receivers in pleasure cars. Under-the-car antennas, made necessary 

 by introduction of all metal automobile tops, inclusion of the radio 

 control as a part of the instrument board, and the use of circuits for 

 reducing ignition noise are the more important features of 1935 

 developments. 



Photons and Electrons} Karl K. Darrow. In a book entitled 

 "Biological EfYects of Radiation" edited by Professor B. M. Duggar 

 of the University of Wisconsin, Dr. Darrow contributes the first 

 chapter of 42 pages. In descriptive and brief manner the following 

 topics are discussed: \\'aves and Corpuscles; Monochromatic light and 

 measurement of wave-length; External photoelectric effect and 

 measurement of photon energy; Units of wave-length, wave number, 

 frequency, and photon energy; Regions of the spectrum; Absorption 

 of light by atoms; Continua in absorption spectra, and ionization by 

 light; Theory of absorption lines; Terms; Absorption in X-ray region; 

 Emission of light; X-ray emission spectra; Production of X-rays; 

 Production of light of the optical spectrum; Scattering of light without 

 change of frequency; Scattering of light with change of frequency; 

 Scattering of X-rays; Transmutation of electron-pairs and photons. 



Neutralizing Transformer to Protect Power Station Communication} 

 E. E. George, R. K. Honaman, L. L. Lockrow, E. L. Schwartz. 

 The use of commercial telephone circuits by power companies for a 

 wide range of communication services including not only telephone 

 but also telemetering, remote alarms, supervisory control and pilot 

 wire control has focused attention on the problems of protection of 

 this type of service. Where such circuits enter power stations which 

 are subject to rise in ground potential at times of faults, the neutralizing 

 transformer provides a means of securing adequate protection. Cir- 

 cuits operated into power stations through neutralizing transformers 

 experience no adverse effects from potential rise up to 4,000 volts 

 r.m.s. This result is produced by causing the transformer to introduce 

 into affected communication circuits a counter voltage to neutralize 

 the difference in ground potential. Transformers for indoor and out- 

 door use have been designed. The characteristics are such that they 

 produce substantially no adverse reaction upon the transmission over 

 the communication circuits they protect. Trials were made in the 

 territory of the Tennessee Electric Power Company. In five locations 



2 Chapter in book, "Biological Effects of Radiation," Vol. I, McGraw-Hill Book 

 Company, Inc., 1936. 



' Elec. Engg., May, 1936. 



