﻿208 
  

  

  REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  

  

  [24] 
  

  

  a 
  socket, 
  D, 
  and 
  on 
  the 
  other 
  end 
  is 
  formed 
  the 
  thread 
  of 
  a 
  screw, 
  E, 
  

   about 
  half 
  an 
  inch 
  long, 
  and 
  just 
  above 
  it 
  is 
  a 
  small 
  pin 
  or 
  stop, 
  F, 
  on 
  

   the 
  spindle. 
  G 
  is 
  a 
  sliding 
  stop-piece, 
  against 
  which 
  the 
  pin 
  F 
  impinges 
  

   when 
  the 
  thermometer 
  is 
  adjusted 
  for 
  use. 
  The 
  screw 
  E 
  works 
  into 
  

   the 
  end 
  of 
  the 
  case 
  B 
  the 
  length 
  of 
  play 
  to 
  which 
  it 
  is 
  adjusted. 
  The 
  

   number 
  of 
  turns 
  of 
  the 
  screw 
  into 
  the 
  case 
  is 
  regulated 
  by 
  means 
  of 
  the 
  

   pin 
  and 
  stop-piece. 
  The 
  thermometer 
  in 
  its 
  case 
  is 
  held 
  in 
  position 
  by 
  

   the 
  screw 
  E, 
  and 
  descends 
  into 
  the 
  sea 
  in 
  this 
  position, 
  the 
  fan 
  C 
  not 
  

  

  /T\ 
  

  

  ^ 
  

  

  izr 
  

  

  )» 
  

  

  Fig. 
  16. 
  — 
  The 
  Magnaglii 
  deep-sea 
  thermometer. 
  

  

  acting 
  during 
  the 
  descent 
  because 
  it 
  is 
  checked 
  by 
  the 
  stop 
  F. 
  When 
  

   ascent 
  commences 
  the 
  fan 
  revolves, 
  raises 
  the 
  screw 
  E, 
  and 
  releases 
  the 
  

   thermometer, 
  which 
  then 
  turns 
  over 
  and 
  registers 
  the 
  temperature 
  of 
  

   that 
  spot, 
  owing 
  to 
  the 
  axis 
  H 
  being 
  below 
  the 
  center 
  of 
  gravity 
  of 
  the 
  

   case 
  B, 
  as 
  adjusted 
  for 
  the 
  descent. 
  Each 
  revolution 
  of 
  the 
  fan 
  repre- 
  

   sents 
  about 
  10 
  feet 
  of 
  movement 
  through 
  the 
  water 
  upward, 
  so 
  that 
  the 
  

   whole 
  play 
  of 
  the 
  screw 
  requires 
  70 
  or 
  80 
  feet 
  ascent; 
  therefore 
  the 
  

  

  