Abstracts of Technical Articles from Bell System Sources 



Recent Observations on the Relation between Penetration, Infection and 

 Decay in Creosoted Southern Pine Poles in Line} C. H. Amadon. 

 The relation between poor penetration and decay, and the necessity 

 for rational and adequate penetration requirements in treating 

 specifications, are now fairly well understood by producers and users 

 of creosoted southern pine poles. The purpose of this brief paper is 

 to supplement the information presented in the Proceedings for 1936 

 and 1937 on the behavior of these poles in line under actual service 

 conditions. 



Tarnish Studies. The Electrolytic Reduction Method for the Analysis 

 of Films on Metal Surfaces} W. E. Campbell and U. B. Thomas. 

 A method is described for analysis of tarnish films on metals by 

 electrolytic reduction at the cathode. Its suitability is demonstrated 

 for the rapid and accurate measurement of oxide films on copper 

 varying in average thickness from monomolecular layers to 1000 A. 

 It is shown to be useful for reduction of mixed oxide-sulfide films on 

 copper and silver. The method is used to measure the oxide films 

 on freshly reduced copper after one-half hour's exposure to oxygen 

 or air. Such films are shown to be 10-20 A thick. A thicker film, 

 measuring 30-70 A is found to be produced by abrasion of copper in 

 air, water, benzene or toluene. Adaptations and modifications are 

 discussed which give wide analytical application to the method. 



An Electrochemical Study of the Corrosion of Painted Iron? H. E. 

 Haring and R. B. Gibney. The corrosion protective value of 

 approximately 50 difi^erent paints was determined by means of an 

 electrochemical method which has been previously described. This 

 determination involved the measurement of the change in the potential 

 of the painted iron with time when wet with water for 24 hr. or less. 

 It was found that the interpretation of the time-potential curves 

 which were automatically plotted by a recording vacuum tube elec- 

 trometer, was facilitated if the test was conducted in a nitrogen 

 atmosphere. The results obtained with the electrochemical or 

 potentiometric method compared favorably with those obtained in a 



1 Proc. American Wood-Preservers' Association, 1939. 



2 Electrochemical Society Preprint 76-25. 

 ^ Electrochemical Society Preprint 76-24. 



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