﻿456 
  Mr. 
  W. 
  Spottiswoode 
  on 
  Stratification 
  in 
  [June 
  10, 
  

  

  Tig. 
  1. 
  

  

  End 
  elevation 
  of 
  Contact-breaker. 
  Half 
  size 
  (linear). 
  

  

  A. 
  Mahogany 
  base. 
  

  

  B. 
  Heavy 
  brass 
  column 
  for 
  supporting 
  vibrating 
  spring. 
  

  

  C. 
  Vibrating 
  spring. 
  

  

  D. 
  Brass 
  column 
  for 
  supporting 
  horizontal 
  plate, 
  O. 
  

  

  E. 
  Platinum-tipped 
  screw 
  for 
  contacts. 
  

  

  F. 
  Friction-collar 
  for 
  holding 
  steadying-arm. 
  

   Gr. 
  Steadying-arm. 
  

  

  H 
  H. 
  Terminals. 
  

   1 
  1. 
  Electromagnet. 
  

  

  K. 
  Lever-arm 
  for 
  fine 
  adjustment. 
  

  

  L. 
  Levelling-screw. 
  

   M 
  M. 
  Compensating 
  weights. 
  

  

  N. 
  Wooden 
  pillar 
  for 
  electromagnet. 
  

  

  