﻿Phil. 
  Mas;. 
  Ser. 
  6, 
  Vol. 
  16, 
  PI. 
  XII. 
  

  

  The 
  OEA, 
  an 
  Apparatus 
  for 
  making 
  Observatory 
  Experiments. 
  

  

  fofu 
  moies/fed. 
  

  

  I 
  ^-> 
  fris-d>apAraa?n 
  tarttcA 
  Umits 
  ffee 
  aperture 
  tf 
  T, 
  'and 
  a, 
  

   Protetest(/pe 
  ' 
  slring-frame 
  info 
  trfizch 
  a 
  scale 
  graduated 
  on 
  y/ass 
  zs 
  fitted 
  

  

  ilA 
  ik 
  separate 
  skmd 
  

  

  W7m 
  -/> 
  ' 
  SMnheil 
  /em, 
  to 
  ie 
  placet/ 
  at 
  B 
  n>ten 
  ffie 
  pro-telescope 
  ts 
  re/navea?. 
  

   ScAU 
  OF 
  THE 
  D//>Cff/IM, 
  0/V£- 
  Te/VTH 
  . 
  

  

  In 
  this 
  diagram- 
  

  

  T' 
  is 
  the 
  pro-telescope, 
  

  

  z' 
  is 
  the 
  pro-planet, 
  

  

  or 
  some 
  part 
  of 
  it, 
  

  

  ^>Jrts 
  diapf/ 
  ragm 
  ti/ti/i 
  srr/np-fra/rzc 
  

   uito 
  ie/bicA 
  isfitfed 
  a 
  piece, 
  ofcopperfoit' 
  

   p/ei-reat 
  tyro, 
  ffee 
  7rwnu.ee- 
  t'o/e 
  s> 
  

  

  