216 



IOWA ACADEMY OF SCIENCE 



THE RESULTS. 



Introduction and general discussion. The experiments soon 

 showed that there are three distinct states, from one to another 

 of which the wires would change. The conditions under which 

 these changes occur are very complicated but in this paper some 

 of the conditions will be dealt with. The three period-ampli- 



ZtOr 



10 is 



Fig. 29. 



tude curves representing the three typical states are shown in 

 iigure 29. For convenience and brevity in discussion these will 

 be numbered. They will be discussed in detail in the latter part 

 of this paper. 



Type I shall be the curve (see figure 29), in which there is a 

 continual decrease in the period as the amplitude decreases. 

 This departure from a constant period varies greatly in magni- 

 tude in the different wires and with the conditions imposed upon 

 the experiment; as variations in the load and the approximate 

 period. The same holds true also in the other types of curves. 

 Wires when following this type of curve will be said to be in 

 slate I. 



