Table 267. 



EFFECT OF ELONGATION ON THE SPECIFIC RESISTANCE OF SOFT 



METALLIC WIRES.* 



Table 268. 



EFFECT OF ALTERNATING THE CURRENT ON ELECTRIC RESISTANCE. 



This table gives the percentage increase of the ordinary resistance of conductors of different diameters 

 when the current passing through them alternates with the periods stated in the last column.f 



Smithsonian Tables. 



• T. Gray, " Trans. Roy. Soc. Edin." 1880. 



t W. M. Mordey, " Inst. El. Eng. London," 1889. 



258 



