﻿m 
  

  

  REPORT 
  ON 
  THERMOMETERS. 
  

  

  191 
  

  

  The 
  last 
  eleven 
  showed 
  a 
  maximum 
  error 
  of 
  0.3°, 
  minimum 
  0°,mean 
  0.07°. 
  

   A 
  single 
  instrument 
  gave 
  the 
  very 
  largo 
  error 
  of 
  maximum 
  1.8°, 
  mini- 
  

   mum 
  1°, 
  mean 
  1.5°, 
  due 
  to 
  the 
  sliding 
  of 
  the 
  tube 
  

   on 
  the 
  scale, 
  the 
  tip 
  of 
  the 
  tube 
  holding 
  it 
  at 
  the 
  

   top 
  having 
  been 
  broken 
  off. 
  These 
  instruments 
  

   would 
  be 
  greatly 
  improved 
  by 
  being 
  pointed 
  

   also 
  upon 
  their 
  stems. 
  

  

  (3) 
  Thermometers 
  attached 
  to 
  the 
  Coast 
  Surrey 
  

   u 
  saUnomcter 
  v 
  cans. 
  — 
  Simple 
  tubes, 
  with 
  round 
  

   bulbs, 
  protected 
  by 
  a 
  perforated 
  brass 
  cage, 
  grad- 
  

   uated 
  to 
  1° 
  intervals 
  upon 
  a 
  white-metal 
  scale. 
  

   Since 
  March, 
  1885, 
  graduated 
  also, 
  upon 
  the 
  steins; 
  

   range 
  from 
  30° 
  to 
  100°. 
  Fitted 
  to 
  slide 
  into 
  the 
  

   front 
  of 
  the 
  Coast 
  Survey 
  salinometercups; 
  made, 
  

   by 
  Giuseppe 
  Tagliabue 
  and 
  John 
  Tagliabue, 
  of 
  

   New 
  York. 
  Used 
  only 
  in 
  connection 
  with 
  salin- 
  

   ometers. 
  

  

  Three 
  of 
  these 
  thermometers 
  (old) 
  made 
  by 
  G. 
  

   Tagliabue, 
  show 
  a 
  maximum 
  error 
  of 
  1.2°, 
  mini- 
  

   mum 
  of 
  0°, 
  and 
  mean 
  of 
  0.5°. 
  Five 
  made 
  by 
  J. 
  

   Tagliabue 
  show 
  a 
  maximum 
  of 
  1.1°, 
  minimum 
  

   of 
  0°, 
  and 
  mean 
  of 
  0,07°. 
  Six 
  last 
  received 
  from 
  

   J. 
  Tagliabue, 
  pointed 
  on 
  stems, 
  and 
  of 
  improved 
  

   quality, 
  show 
  maximum 
  error 
  of 
  0.6°, 
  minimum 
  

   of 
  0°, 
  and 
  mean 
  of 
  0.2G°. 
  

  

  (1) 
  "AliUer-CaseUa" 
  deep-sea, 
  thermometers. 
  — 
  

   These 
  instruments 
  are 
  a 
  modification 
  of 
  Sixes 
  

   self- 
  registering 
  thermometer, 
  consisting 
  essen- 
  

   tially 
  in 
  the 
  protection 
  of 
  the 
  larger 
  bulb, 
  which 
  

   contains 
  the 
  expansible 
  fluid 
  acted 
  upon 
  by 
  

   changes 
  of 
  temperature, 
  by 
  an 
  inclosed 
  sealed 
  

   glass 
  cylinder 
  nearly 
  filled 
  with 
  alcohol. 
  By 
  this 
  

   device 
  the 
  effect 
  of 
  pressure 
  at 
  great 
  depths 
  be- 
  

   low 
  the 
  surface 
  of 
  the 
  sea 
  is 
  neutralized, 
  the 
  press- 
  

   ure 
  being 
  taken 
  up 
  by 
  the 
  fluid 
  and 
  vapor 
  con- 
  

   tained 
  in 
  the 
  outer 
  cylinder. 
  

  

  The 
  following 
  description, 
  condensed 
  from 
  

   Lieutenant-Commander 
  Sigsbee's 
  Deep 
  -Sea 
  

   Sounding 
  and 
  Dredging 
  (Washington, 
  1880, 
  page 
  

   108), 
  will 
  explain 
  the 
  construction 
  and 
  operation 
  

   of 
  the 
  instrument. 
  (See 
  Fig. 
  5.) 
  

  

  A 
  thermometer 
  tube, 
  bent 
  in 
  the 
  form 
  of 
  U, 
  is 
  

   fastened 
  to 
  a 
  vulcanite 
  frame 
  and 
  backed 
  b} 
  r 
  a 
  white 
  glass 
  slab, 
  marked 
  

   by 
  graduated 
  scales. 
  The 
  limbs 
  terminate 
  in 
  bulbs, 
  one 
  much 
  larger 
  

   than 
  the 
  other, 
  and 
  the 
  U 
  is 
  occupied 
  by 
  a 
  column 
  of 
  mercury 
  which 
  

   serves 
  as 
  an 
  index. 
  The 
  large 
  bulb 
  and 
  part 
  of 
  limb 
  not 
  occupied 
  by 
  

  

  Fig. 
  4. 
  — 
  Professor 
  Baird's 
  pro- 
  

   tected 
  thermometer. 
  

  

  