OF ARTS AND SCIENCES. 311 



Original length 1.56 metres. 



Length to be stretclietl 1.52 ,, 



Resistance of whole length 2G76 „ 



Resistance of length not stretched 0068 „ 



Resistance of wire to be stretched 2608 „ 



/ r- R 



1.52 2.3104 .2608 



1.54 2.3716 .2608 

 1.56 2.'434 .2620 



1.58 2.496 .2620 

 1.6 2.56 .2836 



1.63 2.65 .2956 

 1.655 2.706 .298 

 1.67 2.789 .310 



1.69 2.856 .316 

 1.705 2.907 .3256 



l^ R 



^-^=.794 -=.8 



Wire broke under 5.2 lbs. 



Experiment 9. — Cojiper wire, the Jinest yet. 



Original total length 1.56 



Length to be stretched 1.52 



Original total resistance 780 



Resistance of connecting wires, &c 055 



/ P R 



1.52 2.3104 .725 



1.585 .725 



1.55 2.4025 .725 

 1.565 -2.444 .7298 



1.59 2.528 .7538 

 1.61 2.592 .7766 



1.64 2.6896 .8018 

 1.67 2.789 .8318 



1.70 2.89 .8618 

 1.73 2.993 .8918 

 1.77 3.133 .9314 

 1.81 3.276 .971 

 1.855 3.441 1.006 



/- R 



77= .671 7T-= .7206 



h Ri 



If there were no change, B^ should have been 1.08 ohms. The wire 

 broke under pressure of 2.G lbs. 



From the foregoing experiments, I conclude that the conductivity of 

 German-silver wire remains unaltered by stretching ; that the con- 



