284 HENRY A. EOWLAND 



An ordinary wattmeter in the form of an electrodynamometer with 

 non-inductive coils would give the correct value of this quantity, but 

 any attempt to multiply the mean electromotive force by the current 

 and the cosine of the phase would lead to an incorrect result unless this 

 was done for each harmonic separately. 



It is to be noted that the introduction of condensers to balance self- 

 induction will only work for one period at a time. 



Indeed very many of the results hitherto obtained by observers and 

 theorists will require modification in the presence of these harmonics. 



It would seem from the above that the transmission of a current for 

 electric lighting is quite a different thing from the transmission of a 

 suitable current for motors. It will be remembered that the transmis- 

 sion in the Frankfort-Lauffen experiment was one of a lighting current 

 alone and that some mystery seems to hang over the motor tests. Can 

 the presence of these harmonics have anything to do with this ? 



