230 



IOWA ACADEMY OF SCIENCE 



figure 39. There is seen a tendency for type II to have a more 

 rapid rate of loss than type III. Below an amplitude of 200 

 degrees (with a 30 cm. suspension), the rates of loss are essen- 



700 



lor, 



Zvo 300 400 



Fig. 39. 



*>oo 



1 ially equal. Table IV shows the calculations for one of each 

 type of curves. It is seen from these data that the difference 

 between the successive angles is quite large and the calcula- 

 tions are thus only approximate. The data should be taken 

 very accurately and the curves plotted on a large scale so that 

 the rates of loss of energy may be compared. Time would not 

 permit a more careful study of this point at this time. 



