upon the Dimensions of Iron and Steel Bars. 8 1 



Everything being left in the same position, the electricity 

 was now transmitted in the + or contrary direction, so as 

 first to remove the polarity acquired by the — current, and 

 then to induce the opposite polarity. The total elongation 

 of 10'9, acquired in the last experiment, is carried forvi'ard 

 in the 4th column of the following second table of results. 



Experiment 1 (continued). 



The next series of results was obtained with a fresh bar of 

 exactly the same size and temper as the precedino-. To 

 avoid an unnecessary occupation of space, I shall omit the 

 fresh heading of the table for a change in the direction of the 

 current, and simply designate the commencement of a new 

 condition by ruling a line. 



Experiment 2. 



