310 PROCEEDINGS OF THE AMERICAN ACADEMY 



Ohm. 



Original resistance with connecting wires 3000 



Resistance of connecting wires 036 



Resistance of total length 2G4 



Resistance of length not stretched 008 



Original resistance of length to be stretched . . . .256 



/ /2 R 



1.57 2.465 .256 



1.58 .256 

 1.595 .256 

 1.6 2.56 .256 

 1.615 2.608 .2608 

 1.64 2.69 .2728 

 1.66 2.7556 .2776 

 1.69 2.856 .2776 

 1.725 2.9756 .2992 

 1.76 3.0976 .3016 



P 2465 ^ R 256 R_ P 



l^ ~ 3097 ~ ■''^^ S^ — 30l6 ~ -^^^ ^1 ^ "^ 



i?j should have been .322 if the conductivity of the metal had not 

 been altered. 



Experiment 8. — Copper wire No. 22. 



Original total length 1.57 metres. 



Length to be stretched 1.53 „ 



Resistance with connecting wires 3048 



Resistance of connecting wires 036 



Resistance of total length 2G88 



Resistance of length not stretched 0068 



Resistance of wire to be stretched 2620 



1.53 2.341 .262 



1.55 2. — .262 



1.59 .262 

 1.62 2.624 .262 

 1.G55 2.739 .30(>4 

 1.68 2.822 .3124 



li R R ^ P 



pf = .829 jr = -841 7T > ,T, 



The wire broke under weight of .3.2 lbs. 



H^ should have been .3161 if there was no chaiige. 

 Experiment 8a. — With copper wire of same size. 



