MORSE AND SHUDDEMAGEN. — AN ALUMINIUM ANODE. 



375 



(58), and others, that it is an equilateral hyperbola, and that therefore 

 the product of apparent capacity and forming voltage is a constant. A 

 careful examination of the data of the curve shows that this is by no 

 means the case. The curve marked B gives the values for the product 

 capacity X forming voltage (in this case applied voltage also), and this 

 should be of course a straight line parallel to the X axis if the product 

 is to be constant. The third curve, C, of Figure 2 gives the value for the 



2.0 



1.6 



5 

 O 



o 



CO 



f. 1.2 



5 



B 



-V 



\ 



\ 



1^ 



D 



16 24 32 40 



VOLTAGE 



Figure 4. 



Capacity at less than forming voltage. For the lower range of voltages. 

 Same times of charge, discharge, and insulation as in Figures 2 and 3. 

 Curve A. Formed at 6 volts. Measured at 6, 4, and 2 volts. 



B. " 10 " " 10, 6, and 2 volts. 



C. " 21 " " 21,10, 6, and 2 volts. 



D. " 41.6 " " 41.6, 21, 10, 6, and 2 volts. 



energy per square centimeter stored in an aluminium anode when vari- 

 ous voltages are applied to it, and this is very nearly a straight line with 

 only a slight curvature for voltages lower than 100. Figure 3 indicates 

 the characteristics of these curves at very low voltages. The data for 

 this particular curve were taken from the measurements of Scott (64), 

 but it is in close agreement with our own results in the same voltage 

 range. It is quite evident that the product of capacity and voltage is 

 not constant, and for these conditions the curvature in the energy curve 

 is also more evident. The values obtained for the capacity of an alu- 



