Triple .Pendulums with Mutual Interacts 



015 



In fig. 1 only two pendulums are visible, the third is 

 "hidden by FP. The positions of the bridles are determined 

 by the three light connectors BB', CO', and DD'. 



The normal oscillations occur in the plane of fig. ~, and 

 are recorded by sand traces on a black-board drawn perpen- 

 dicular to the direction of vibration. 



Fig. 2. — End elevation. 

 A(E) A(E') *(£') 



The trace from Q is received on a narrow black-board. 

 The pendulums are started when all the bobs are just above 

 the boards, and afterwards the board containing the trace 

 from Q is moved until the three initial motions, shown bv 

 the traces, are in the same straight line. 



If the advantages and disadvantages of this arrangement 

 are considered.it is seen : — 



(1) That although the three connectors make For gene- 

 rality, yet if DD' is eliminated, the action of the pendulum-bob 



