MORSE AND SARGENT. — RESISTANCE OF LEAD ACCUMULATOR. 599 



each other, and by no means indicates that the resistance of the cell is 

 the same as that of sulphuric acid of the same concentration between 

 a pair of platinum electrodes placed in the same geometrical position 

 as the " average plate surfaces." The plate resistance is not negligible 

 and its negative temperature coefficient may account for the higher 

 resistance at the higher temperature in part at least. That the resist- 

 ance of the plate itself enters is clearly shown by the fact the pasted 



TABLE II. 



Internal Resistance of a Plante Cell during Discharge 

 AT 2 Amperes. Temperature 8.5° C. 



plates of slightly greater area, "placed as nearly as possible the same 

 distance apart, show a decidedly greater resistance on open circuit than 

 that of these Plantd plates, which have a solid lead web and lead ribs 

 running their whole length. The cells with pasted plates have nearly 

 .01 ohni more resistance. 



8. The values of Table 2 are plotted in the upper curve of Figure 5, 

 and they show the characteristic course of changes in this particular 

 type of plate. The cell changes its internal resistance a little more 

 than 100 percent during complete discharge, and by the time the last 

 value on the list is reached the cell voltage has dropped to zero. 



