ARTICLES BY BELL SYSTEM AUTHORS 487 



tances from about 0.001 /x/xf to 50 ju/xf. Modern test oscillators, with fre- 

 quency and capacitance measuring apparatus as auxiliary equipment, will 

 measure these quantities with accuracies sufficient to meet present needs. 

 The transmission measuring circuit also is described and is proposed as the 

 standard reference circuit for comparison with the test oscillators. 



Electro Spot Testing and Electrography* H. W. Hermance^ and H. V. 

 Wadlow.^ Reprinted from A.S.T.M., Special Technical PMication No. 

 98, pp. 12-34, 1950. 



* A reprint of this article may be obtained on request to the editor of the B. S. T, J. 

 » B. T. L. 



