LAWS. — RECORDING ALTERNATING CURRENT WAVES. 



323 



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

 series with reactive coil. 



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

 cordance of tiie readings. 



Figure 5. — yl, 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 a quarter- 

 phase synchronous motor running idle with the field adjusted for iniiiinuim ciirreiit. 

 Source of power was a three-phase dynamo with phasing transfornifrs arraiiiied 

 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 



