PEIRCE. — OSCILLATIONS OF SWINGING BODIES. 85 



that caused by the measured steady current in the solenoid, and a 

 fairly approximate value of the moment of the magnet was computed 

 from the H thus found and the results of measurements made with the 

 magnet in the induction coefficient apparatus described above. When 

 these quantities were known, it was comparatively easy to determine /3 

 from the equation {it 2 + \ 2 )/T 2 = /3 2 , and then to get an approximate 

 value of the apparent moment of inertia of the swinging system from 

 the formula / = MHT 2 /{tt 2 + X 2 ). Some of the results obtained by 

 studying many records of the motion of this suspended system are 

 given in the next table. 



TABLE X. 



Period. M H. Damping Coefficient. Logarithmic Decrement. 



As has been said above, it is possible to obtain from these data values 

 for the apparent moment of inertia of the oscillating system, but since 

 a slight change in any one of several of the quantities measured might 

 introduce a great change in the quantity computed, the results must 



