﻿new Harmonic, Analyser, 111 



fig. 2. There may be any finite number of such discontinuities. 

 For our purposes it is necessary to make the curve con- 

 tinuous by joining the two points C and C by a straight 



Fig. 1. 



line. If the curve represents a periodic phenomenon with 

 period c, then the ordinate for x = c will, as a rule, equal the 

 initial ordinate for x = (as in fig. 1). The curve when 

 repeated along the axis of x will therefore be continuous. 



Fig. 2. 



Otherwise there will be a discontinuity as at B in fig. 2. In 

 this case also the curve has to be continued from its end point 

 B' along the last ordinate to a point B" which has the same 

 ordinate as the initial point A', so that the line A' B" is 

 parallel to the axis of x. 



We can now express the equation to the curve in the form 



