LAWS. — RECORDING ALTERNATING CURRENT WAVES. 



323 



Figure 4. — Potential difference between the carbons of an enclosed arc, in 

 series with reactive coil. 



The curves were taken about one minute apart with a view to testing the con- 

 cordance of the readings. 



Figure 5. — A, potential difference between the terminals of a small alternat- 

 ing current motor. B, current through motor. 



Figure 6. — Curve A is E.M.F., and B is current in one phase of aquarter- 

 pliase synchronous motor running idle with the field adjusted for minimum current. 

 Source of power was a three-phase dynamo with phasing transformers arranged 

 on the Scott system. 



current curves by the use of a drop wire, as indicated in Figure 1. In 

 starting the arrangement it is very easy to determine when the proper 



