298 HENEY A. KOWLAND 



able to detect any electric absorption, although I have no doubt one 

 of the more accurate methods will show it. 



With a condenser, probably of waxed paper, he found 



Number of complete Capacity in Apparent resistance 



periods per second. microfarads. in ohms. 



14-0 4-64 139-6 



32-0 4-96 34-1 



53-3 4-96 20-5 



131-1 4-94 5-2 



The first value of the capacity seems to be in error, possibly one of 

 calculation. However, the result seems to show a nearly constant 

 capacity but a resistance increasing rapidly with decrease of period, as 

 Maxwell's formula show. The constant value of the capacity remains 

 to be explained. 



Mr. Penniman will continue the investigation with other condensers, 

 liquid and solid, as well as plates in electrolytic liquids. 



The results in the other measurements have been fairly satisfactory, 

 but many of the better methods have only been recently discovered and 

 are thus untried. But we must acknowledge at once that work of the 

 nature here described is most liable to error. Every alternating cur- 

 rent has, not only its fundamental period, but also its harmonics, so 

 that very accurate absolute values are almost impossible to be obtained 

 without great care. To eliminate them, I propose to use an arrange- 

 ment of two parallel circuits, one containing a condenser and the other 

 a self-inductance, each with very little resistance. The long period 

 waves will pass through the second side and the short ones through the 

 condenser side. By shunting off some of the current from the second 

 side, it will be more free from harmonics than the first one. 



However, in a multipolar dynamo, especially one containing iron, 

 there is danger of long period waves also, which this method might 

 intensify. A second arrangement, using the condenser side, might 

 eliminate them. However, many dynamos without iron and without 

 too many poles and properly wound produce a very good curve without 

 harmonics, especially if the resistance in the circuit is replaced by a 

 self inductance having no iron. These remarks apply only to absolute 

 determinations. Eatios of inductance, self and mutual, and capacity 

 are independent of the period, and thus it can always be eliminated. 

 Measurements of resistances also are independent. 



But there are other errors which one who has worked with continuous 



