Di Bella 



center of gravity of the device. The device was tested with one mass and with 

 two masses, at different numbers of revolutions. The trajectory described by 

 the penpoint in the various cases is shown in Fig. 24. We have: 



(1) one arm and N = 150 



(2) one arm and N = 200 



(3) one arm and N = 224 



(4) one arm and N = 318 



(5) two arms and N = 132 



(6) two arms and N = 170 



(7) two arms and N = 210 



(8) two arms and N = 250 



Fig. 24 - Trajectories described 

 by penpoint for various tests on 

 the forward motion of a device 



It is clearly noted that for each revolution of the motor shaft, we have a 

 forward motion (sj and a backward motion (sj) of the device. The second is 

 much smaller than the first. For example, we have: 



= 200 and a device with one arm 

 = 224 and a device with one arm 

 = 250 and a device with two arms. 



Graph Using the Oscillograph 



In order to complete the series of experiments, it was considered suitable 

 to have a graph of the variation of N and of the motor power during a 360° 

 rotation of the motor shaft. Siemens oscillographs were used, and altogether 

 there were carried out eighty graphs of tension, current, and N on devices with 

 one mass or two masses. 



Figure 25 shows one of these graphs. It was carried out on the device indi- 

 cated in Fig. 9 fixed to the floor, and having a single rotating mass. In the 



1390 



