﻿the 
  Electromotive 
  Force 
  of 
  Clark 
  Cells 
  with 
  Temperature. 
  289 
  

  

  up 
  into 
  compartments 
  by 
  means 
  of 
  the 
  zinc 
  plates, 
  a,b,c,... 
  

   C, 
  the 
  inner 
  glass 
  vessel, 
  contains 
  the 
  cells, 
  and 
  rests 
  about 
  

   one 
  and 
  a 
  half 
  inches 
  from 
  the 
  bottom 
  of 
  the 
  outer 
  bath 
  on 
  

   the 
  parts 
  of 
  the 
  partitions 
  a,b,c, 
  . 
  . 
  . 
  which 
  reach 
  to 
  the 
  centre. 
  

   g 
  is 
  the 
  separate 
  compartment 
  containing 
  the 
  heating-coil 
  L, 
  

   the 
  coil 
  of 
  lead 
  tubing 
  K, 
  and 
  the 
  centrifugal 
  pumping-vanes 
  

   Y. 
  The 
  vanes 
  V 
  are 
  directly 
  coupled 
  to 
  a 
  motor 
  with 
  a 
  

   vertical 
  shaft, 
  this 
  being 
  found 
  to 
  be 
  the 
  most 
  satisfactory 
  

   way 
  of 
  driving 
  them. 
  The 
  ring 
  A 
  separates 
  the 
  chamber^ 
  

   into 
  two 
  parts 
  : 
  in 
  the 
  upper, 
  the 
  vanes 
  work 
  and 
  the 
  oil 
  is 
  

   rotating 
  ; 
  in 
  the 
  lower, 
  the 
  heating 
  and 
  cooling 
  coils 
  are 
  

   placed, 
  the 
  oil 
  in 
  this 
  part 
  not 
  rotating, 
  m 
  is 
  a 
  distributing 
  

   plate 
  under 
  the 
  hole 
  in 
  the 
  centre 
  of 
  the 
  ring 
  h, 
  which 
  makes 
  

   the 
  circulating 
  oil 
  pass 
  over 
  the 
  heating 
  and 
  cooling 
  coils. 
  

   D 
  is 
  a 
  stationary 
  guide 
  vane 
  which 
  helps 
  to 
  deflect 
  the 
  

   rotating 
  oil 
  into 
  the 
  next 
  chamber 
  X. 
  

  

  The 
  oil 
  passes 
  under 
  the 
  division 
  b, 
  over 
  c, 
  under 
  d, 
  over 
  e, 
  

   and 
  finally 
  under 
  f 
  into 
  the 
  heating-chamber 
  a, 
  w 
  T 
  here 
  it 
  

   passes 
  over 
  the 
  heating-coil, 
  and 
  is 
  sucked 
  up 
  through 
  the 
  

   hole 
  in 
  the 
  plate 
  h, 
  and, 
  being 
  thrown 
  out 
  by 
  the 
  vanes 
  V, 
  is 
  

  

  Fi*. 
  3. 
  

  

  again 
  circulated. 
  

  

  t 
  

  

  7ZZmZZZZZ2ZZZZZZZZZZ2ZZZZZZZZZZZZZZZZZZZZZZZZZZ 
  

  

  7f777fc 
  

  

  ssss 
  

  

  ^ss 
  

  

  ^ 
  %\\\\ 
  W 
  

  

  ^\\\N\\\ 
  \\ 
  \Ny 
  # 
  

  

  I 
  

  

  m 
  

  

  The 
  circulation 
  obtained 
  by 
  this 
  means 
  was 
  excellent. 
  

   When 
  the 
  bath 
  was 
  tested 
  at 
  a 
  rate 
  of 
  change 
  of 
  temperature 
  of 
  

   1° 
  in 
  eight 
  minutes, 
  there 
  was 
  found 
  to 
  be 
  a 
  maximum 
  differ- 
  

   ence 
  of 
  temperature 
  between 
  any 
  two 
  points 
  of 
  the 
  bath 
  of 
  

   o, 
  2 
  ; 
  while 
  at 
  a 
  rate 
  of 
  change 
  of 
  1° 
  in 
  fifteen 
  minutes, 
  no 
  

   difference 
  in 
  temperature 
  was 
  detected. 
  

  

  In 
  the 
  inner 
  vessel 
  containing 
  the 
  cells 
  (fig. 
  3) 
  the 
  oil 
  was 
  

  

  