434 



ANALYSIS OF CURVES. 



The coefficients were worked out as follows 

 TABLE III. 



NOTE. In the construction of this table it will be seen from the 

 use made of the figures that not all the figures require to be filled in 

 in all the columns. In the present example only 14 out of 30 values of 6 

 are actually required for the harmonics plotted in Fig. 204. In testing 

 for the higher harmonics, however, a greater number of values was 

 required. It is best, therefore, to put down the first column complete, 

 and to fill in the further columns as required. 



Unless this curve is found on trial to be a simple sine 

 curve, determine the next higher harmonic say 5th 

 and again subtract its ordinates from the residual curve. 

 Proceed thus until only the fundamental is left. In 

 practice the third and fifth (and occasionally the seventh) 

 harmonics will be the only ones to be determined. 



The figures given (Table III.) are taken from the 

 same curve (Fig. 204) as that from which Table II. was 

 derived. 

 3rd Harmonic. 



Cosine Term. 



Sine Term. 



