Possible Existence of Mutual Induction between Masses. 599 



Therefore the value of A mom . = 9 x I'M x 10 9 grm. cm./sec. 

 So that the ratio 



^^ =4-8/9 x 1-24 x 10 9 = 4'3 x 10" 10 . 



-"•mom. 



Thus, by the introduction of the suspended screen and 

 other refinements, the steadiness o£ B while A was running- 

 was so much improved that we can now slate that for the 



apparatus shown in fig. 2 the ratio of mom - . i s less than 



5 x 10 -10 . ^-morn. 



It will be seen from fig. 4 that the swinging of B is 

 getting gradually out of phase with the impulses 3, 4, and 5. 

 This is evidence that the increased motion of: B is partly due 

 to some cause in phase with the velocity of A, while the effect 

 looked for should be in phase with the acceleration of A. 



Appendix I. 



Steel Flywheel (A) (shoivn in Fig. 2). — The flywheel takes 

 the form of a solid disk of cast steel 22 in. in diameter and 

 41 in. thick. 



The speed of revolution is 2700 revs, per min. 



Angular velocity, 2700 x 27r/(j0 radians per second 

 = 2-83 x 10 2 radians per second. 



Radius of gyration = ? V 2/2. 



= 11 x 2-54x1-414/2 cm. 

 = 19-9 cm. 



Velocity of a point at the radius of gyration 



= 19-9 x 2-83 x 10 a cm. per sec. 

 = 5"b"5 x 10 :! cms. per sec. 



Weight of flywheel =480 lb. = 220 kg. 

 Angular momentum = 5*65 x 10 3 x 2*20 x 10 5 grm. per sec. 

 = l-24xl0 9 . 



units. 



The kinetic energy =0*5 x 220 x 10 3 X (5'65 X 10 3 ) 2 grm. 



cm. units. 

 = 3'5 x 10 12 grm. cm. units. 



Porcelain Disk (B) (Fig. 3). 



Weight = 10*5 kg. (actual measurement). 



Overall diameter =51 cm. 



