﻿Phil. 
  Mag, 
  Ser. 
  6, 
  Vol. 
  18, 
  PI, 
  IV. 
  

  

  

  

  

  k 
  

  

  

  !| 
  

  

  ■j0 
  

  

  I.. 
  

  

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  ^' 
  ""^ 
  

  

  J 
  

  

  w 
  

  

  (i 
  

  

  

  

  1 
  

  

  Fig. 
  2. 
  — 
  Violin 
  as 
  mounted 
  for 
  the 
  Experiments. 
  

  

  I'lG. 
  1. 
  — 
  Diagram 
  of 
  Optical 
  Arrangements. 
  

  

  Fig. 
  5. 
  — 
  Experimental 
  A: 
  

  

  Fig. 
  y. 
  — 
  A'iolin 
  with 
  Bracket 
  for 
  

   Optical 
  Lever, 
  

  

  Fie. 
  4.— 
  Bracket 
  for 
  Optical 
  lever. 
  

  

  