224 



IOWA ACADEMY OP SCIENCE 



regularities became very marked as the wire was shortened. 

 These are not to be explained alone by the small error in the tim- 

 ing of the vibrations since the same tendency was noted also 

 with the longer periods, where the error was the same as with 



/3.4 



5~ to 



Fig. 35. 



10 



the longer suspensions. A comparison of figures 34, 35 and 36 

 will illustrate this point. All the curves are of wire No. 4 

 under a load of 154 grams. Figure 35 shows the period-ampli- 

 tude curve for a 30 cm. suspension. The curve for a piece of 



Rnvf 



Fig. 36 



15 



20 



this wire, 8.9 cm. long, is shown in figure 34. Figure 36 shows 

 the same piece vibrating with a period approximately the same 

 as that of figure 35. 



It is very probable that the shorter wires display more nearly 

 the actual conditions in the wire whereas there may be a neutral- 

 ization of some pecularities in the longer wires. 



When the periods were kept constant with the above lengths 

 the curves were somewhat more satisfactory but still had a 

 great tendency toward irregularity. This point requires further 

 investigation. 



