226 



BELL SYSTEM TECHNICAL JOURNAL 



untreated commercial textiles, the matter of compensation becomes 

 difficult or entirely impracticable. 



In addition to maintaining transmission losses at a minimum, it is 

 required in certain toll apparatus that the capacitance and conductance 



3.0 



2.6 



2.6 



2.4 



2.2 



2.0 



1.0 



55 



60 



65 



70 



PERCENT RELATIVE HUMIDITY 

 Pig 8— Transmission loss in 50 feet of twisted pair 22-gauge wire insulated with 

 double servings of equal thickness. 



of the parts of the electric circuits be balanced to prevent interference 

 between adjacent circuits which would increase the noise level and 

 impair the quality of voice transmission. Such circuits are usually 

 wired with four-conductor wire and it is required that the character- 

 istics of the insulation and the spacing of the conductors shall be suffi- 



