310 PROCEEDINGS OP THE AMERICAN ACADEMY 



Ohm. 

 Original resistance with connecting wires 3000 



Eesistance of connecting wires 036 



Eesistance of total length 264 



Eesistance of length not stretched 008 



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



/ /2 72 



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 8.0976 .3016 



P 2465 ^ R 256 R P 



ij ~ 3097 ~ •''^^ T^~ m6~ -^^^ ^ -^ "^ 



H^ 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 



Eesistance of connecting wires 036 



Eesistance of total length 2688 



Eesistance of length not stretched 0068 



Eesistance of wire to be stretched 2620 



1.53 2.341 .262 



1.55 2. — .262 



1.59 .262 

 1.62 2.624 .262 

 1.655 2.739 .3004 

 1.68 2.822 .3124 



P R R P 



__ = .g29 - = .841 ^^ > J,, 



The wire broke under weight of 5.2 lbs. 



Ji, should have been .3161 if there was no chanse. 



J. O 



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



