ABSTRACTS OF TECHNICAL ARTICLES 363 



evidence used in judging the quality of current product as a part of 

 any scientific plan of making use of hindsight as well as foresight in 

 controlling quality. 



The Ionizing Effects of Meteors.^ A. M. Skellett. It is shown 

 that a meteor of average velocity has enough energy to cause ioniza- 

 tion of atmospheric gases by impact. Recent experimental work by 

 Frische and others on collisions of ions is interpreted as supporting the 

 hypothesis that meteoric collisions do result in ionization. The after- 

 glow of nitrogen is considered as a possible example of the process 

 by which a meteor train remains glowing for a period of minutes and 

 the coincidence of the region in which such trains are generally ob- 

 served and of the E region of the upper atmosphere is pointed out. 

 The spectra of bright meteors, while not showing atmospheric lines, 

 are shown not to be inconsistent with the above hypothesis. 



The behavior of the transatlantic short-wave radio telephone 

 circuits of the American Telephone and Telegraph Company, during 

 1930, 1931, and 1932, is examined for possible meteoric effects. It is 

 concluded that, in general, a rather large shower is necessary to affect 

 them appreciably. This was to be expected since these circuits are 

 normally under a continuous bombardment by random meteors. It 

 seems possible that a certain degree of the variability (rapid fading, 

 etc.) of received signals over such paths is due to this bombardment. 



Results of radio pulse studies of the upper atmosphere, particularly 

 by Schafer and Goodall, which are strongly suggestive of meteoric 

 ionization, especially at times of special meteoric activity, are (1) 

 sudden increases in ionization in the E region lasting for a period of 

 minutes or less, and (2) increases of longer duration with maxima 

 coincident in time with those of observed meteoric activity. Such 

 tests made during the Leonid shower of November, 1932, were suc- 

 cessful in correlating sudden increases in ionization in the E region 

 with the visual observations of a number of bright meteors passing 

 overhead. For the brightest meteor observed, the ionization increased 

 to a value in excess of summer noon conditions. 



It is pointed out that meteoric showers might take place in the F 

 region which would be unobservable by ordinary visual means. 



Taking into account the energy spent by the meteor in ionization, 

 a mass for the brightest meteor, for which correlative data was ob- 

 tained is roughly calculated to be 0.3 gram. Its estimated brightness 

 was — 1 magnitude. 



The recombination coefficient at the height of the E region is calcu- 



^Proc. I.R.E., February, 1935. 



