﻿202 
  

  

  REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  

  

  [18] 
  

  

  (perhaps) 
  to 
  the 
  difference 
  in 
  pull 
  between 
  a 
  long 
  and 
  a 
  short 
  column 
  of 
  

   mercury, 
  upon 
  the 
  main 
  body 
  at 
  the 
  breaking 
  point. 
  The 
  possible 
  op- 
  

   eration 
  of 
  this 
  cause, 
  tending 
  to 
  break 
  the 
  column 
  a 
  little 
  nearer 
  or 
  a 
  

   little 
  farther 
  away 
  from 
  the 
  narrowest 
  constriction, 
  is 
  not 
  made 
  very 
  

   obvious 
  by 
  the 
  comparisons, 
  although 
  it 
  may 
  explain 
  some 
  individual 
  

   peculiarities 
  which 
  have 
  been 
  noted. 
  

  

  As 
  to 
  such 
  individual 
  peculiarities 
  the 
  following 
  notes 
  may 
  b6 
  of 
  in- 
  

   terest 
  as 
  illustrating 
  the 
  frequency 
  with 
  which 
  these 
  instruments 
  have 
  

   been 
  found 
  to 
  break 
  column 
  in 
  the 
  wrong 
  place 
  : 
  

  

  Three 
  of 
  the 
  instruments 
  were 
  noted 
  as 
  very 
  slow 
  in 
  breaking 
  ; 
  two 
  

   broke 
  column 
  frequently 
  in 
  the 
  wrong 
  place; 
  one 
  did 
  not 
  break 
  at 
  all, 
  on 
  

   one 
  trial, 
  at 
  92°, 
  but 
  broke 
  correctly 
  on 
  repetitions 
  of 
  the 
  experiment 
  ; 
  

   two 
  broke 
  colum 
  once 
  in 
  the 
  wrong 
  place 
  (one 
  at 
  49.8°, 
  one 
  at 
  60°), 
  but 
  

   not 
  again 
  during 
  frequent 
  repetitions 
  of 
  the 
  experiment. 
  One 
  was 
  found 
  

   (at 
  32°) 
  to 
  hold 
  back 
  the 
  separated 
  part 
  of 
  the 
  column 
  after 
  being 
  in- 
  

   verted, 
  read, 
  and 
  returned 
  to 
  the 
  bnlb-downward 
  position. 
  

  

  Several 
  series 
  of 
  experiments 
  were 
  made 
  to 
  determine 
  the 
  sloieness 
  of 
  

   the 
  instruments. 
  Thus, 
  Fish 
  Commission 
  No. 
  5206 
  (maker's 
  No. 
  51452), 
  

   immersed 
  in 
  melting 
  ice, 
  fell 
  : 
  

  

  In 
  1 
  minute 
  from 
  64° 
  to 
  43. 
  l 
  c 
  20.9 
  

  

  In 
  2 
  minutes 
  from 
  64° 
  to 
  42° 
  22. 
  

  

  In 
  3 
  minutes 
  from 
  67.5° 
  to 
  33.8° 
  33.7 
  

  

  In 
  4 
  minutes 
  from 
  68° 
  to 
  33.8° 
  34.2 
  

  

  In 
  5 
  minutes 
  from 
  68.2° 
  to 
  35° 
  33.2 
  

  

  In 
  5 
  minutes 
  from 
  66° 
  to 
  35.8° 
  30.2 
  

  

  In 
  6 
  minutes 
  from 
  66° 
  to 
  33. 
  8° 
  32.2 
  

  

  In 
  7 
  minutes 
  from 
  67° 
  to 
  32.4° 
  34.6 
  

  

  In 
  8 
  minutes 
  from 
  65.5° 
  to 
  3*. 
  4° 
  33.1 
  

  

  In 
  9 
  minutes 
  from 
  66.6° 
  to 
  32.4° 
  34.2 
  

  

  The 
  true 
  reading 
  (32.4°) 
  was 
  in 
  this 
  case 
  reached 
  in 
  7 
  minutes. 
  Fish 
  

   Commission 
  No. 
  5184 
  (maker's 
  No. 
  47995), 
  inclosed 
  in 
  a 
  metallic 
  case, 
  

   as 
  in 
  use 
  at 
  sea, 
  and 
  immersed 
  in 
  melting 
  ice, 
  fell: 
  

  

  In 
  1 
  minute 
  from 
  71° 
  to 
  64.2° 
  6.8 
  

  

  In 
  2 
  minutes 
  from 
  62° 
  to 
  41° 
  21.0 
  

  

  In 
  3 
  minutes 
  from 
  62° 
  to 
  40° 
  22.0 
  

  

  In 
  4 
  minutes 
  from 
  76° 
  to 
  39° 
  37.0 
  

  

  