ELECTRIC DISTRIBUTION AND WIRING. 307 



This table is based on a resistance of 10.51 ohms per mil -foot 

 at 75 F., a temperature coefficient of resistance of 0.0022 per 

 degree Fahrenheit, and a density of 3.03 x io~ 6 pound per mil- 

 foot, or 5 5 5 pounds per cubic foot. 



Aluminum. Resistances in above table are to be multiplied 

 by i .6 1 for aluminum wire. 



Weights in above table are to be multiplied by 0.30 for alu- 

 minum wire. 



Iron and Steel. Resistances in above table are to be multi- 

 plied by about 7 for iron and steel wires. 



Weights in above table are to be multiplied by 0.876 for iron 

 and steel wires. 



