226 



Dr. Osborne Reynolds on 



the disturbance were at right angles to that of the axis of 

 elasticity, the body would accumulate the disturbance. 



It thus appears that, if a structure is in a state of 

 vibration, the periods of free vibration and their directions 

 may be ascertained by an Harmonic Analyzer consisting 

 of a small weight with elastic attachments, so adjustable 

 that the period of free vibration of the weight can be varied 

 to any required extent, and the direction of such free 

 vibration turned through all requisite angles. 



This may be accomplished in many ways. That which 

 I have so far adopted with satisfactory success has been, 

 very simple. 



iTs ilo 



VT-T] 



Fig. I. 



It consists, as shown in Fig i, essentially of a base formed' 

 of a bar of hard wood, one-and-a-half inches square, and- 



