148 



THE STUDY OF SPEECH CURVES. 



groups, the first being largest and the others decreasing steadily owing 

 to the friction. A single wave in this case therefore consists of a large 

 vibration followed by two smaller ones. Of several such groups in the 

 figure v.-e will select the one reproduced on a large scale in figure 130. 



The next step is to find the axis of the curve. This is not difficult 

 in the present case, because the successive large vibrations that begin 

 each wave are of the same height. A tangential line is drawn along the 

 tops of the two large vibrations that bound the wave to be studied. The 

 distances of the maxima and minima from this line are now to be measured. 

 For this purpose let us use the coordinate measurer (p. 57). The mount 

 is fastened to a board. The coordinate measurer is brought over it; its 

 axis is made parallel to the tangential line, and the apparatus is also fastened 

 to the board. The distances of the successive maxima and minima from 

 the tangential line are found to be 0, 8.3, 0.8, 7.1, 2.5, 6.6mm. The wave 

 represents a vibration which starts strong and gradually dies away. Al- 

 though the successive maxima and minima in this wave are not at exactly 



Thirty-six Ordinates from Figure 130, Multiplied by the Cosixe.s. 



