﻿Obituary. 
  395 
  

  

  of 
  soil 
  moisture 
  to 
  plant 
  life. 
  It 
  bears 
  the 
  marks 
  of 
  careful 
  

   investigation, 
  yet 
  is 
  written 
  in 
  untechnical 
  language 
  and 
  is 
  just 
  

   such 
  a 
  book 
  as 
  should 
  interest 
  and 
  aid 
  those 
  engaged 
  in 
  any 
  form 
  

   of 
  soil 
  tillage. 
  h. 
  e. 
  g. 
  

  

  7. 
  Mesure 
  des 
  Temperatures 
  elevees 
  • 
  par 
  H. 
  Le 
  Chatelier 
  

   et 
  O. 
  Boudouakd, 
  pp. 
  220, 
  8vo. 
  Paris, 
  1900, 
  Bibliotheque 
  de 
  

   la 
  Revue 
  generale 
  des 
  Sciences 
  (Georges 
  Carre 
  et 
  C. 
  Naud). 
  — 
  

   The 
  measurement 
  of 
  very 
  high 
  temperatures 
  is 
  always 
  a 
  matter 
  

   of 
  great 
  interest, 
  whether 
  viewed 
  from 
  the 
  purely 
  physical 
  stand- 
  

   point 
  or 
  from 
  the 
  technical 
  side. 
  The 
  early 
  experiments 
  of 
  

   Wedgwood, 
  dating 
  back 
  more 
  than 
  one 
  hundred 
  years, 
  form 
  a 
  

   starting 
  point 
  in 
  the 
  development 
  of 
  the 
  subject, 
  while 
  the 
  recent 
  

   experiments 
  of 
  Chatelier, 
  Barus, 
  Holborn 
  and 
  Wien, 
  and 
  others 
  

   show 
  how 
  much 
  may 
  be 
  accomplished 
  in 
  this 
  direction. 
  The 
  

   present 
  volume 
  is 
  a 
  very 
  useful 
  and 
  compact 
  resume 
  of 
  the 
  entire 
  

   subject, 
  taking 
  up 
  the 
  various 
  forms 
  of 
  pyrometers 
  in 
  succession, 
  

   according 
  to 
  the 
  physical 
  principles 
  involved 
  in 
  each. 
  The 
  whole 
  

   forms 
  a 
  most 
  interesting 
  discussion, 
  and 
  brings 
  out 
  clearly 
  the 
  

   point 
  which 
  science 
  has 
  now 
  reached 
  as 
  well 
  as 
  the 
  limitations 
  of 
  

   the 
  present 
  methods. 
  The 
  author 
  notes 
  that 
  in 
  order 
  to 
  reach 
  a 
  

   higher 
  degree 
  of 
  precision 
  than 
  has 
  been 
  yet 
  attained, 
  a 
  more 
  

   exact 
  determination 
  of 
  the 
  fixed 
  points 
  serving 
  for 
  the 
  graduation 
  

   of 
  the 
  pyrometer 
  is 
  much 
  to 
  be 
  desired 
  ; 
  since, 
  for 
  example, 
  the 
  

   points 
  of 
  fusion 
  of 
  zinc, 
  silver, 
  and 
  gold 
  are 
  still 
  uncertain 
  to 
  

   some 
  ten 
  degrees. 
  Furthermore, 
  a 
  more 
  precise 
  determination 
  of 
  

   the 
  relation 
  between 
  the 
  electrical 
  resistance 
  of 
  platinum 
  and 
  the 
  

   temperature 
  is 
  needed 
  ; 
  while 
  for 
  the 
  very 
  highest 
  tempera- 
  

   tures 
  it 
  would 
  be 
  useful 
  to 
  have 
  a 
  more 
  definite 
  knowledge 
  of 
  the 
  

   laws 
  of 
  radiation 
  of 
  an 
  absolutely 
  black 
  body. 
  The 
  work 
  is 
  well 
  

   brought 
  up 
  to 
  date 
  and 
  includes, 
  for 
  example, 
  the 
  experiments 
  of 
  

   Holborn 
  and 
  Wien 
  (1896), 
  although 
  the 
  later 
  papers 
  by 
  Holborn 
  

   and 
  Day, 
  of 
  a 
  year 
  ago, 
  with 
  their 
  important 
  results, 
  are 
  not 
  

   mentioned. 
  

  

  Obituary. 
  

  

  Dr. 
  Thomas 
  Preston 
  died 
  at 
  his 
  home 
  in 
  Dublin 
  on 
  March 
  7 
  

   at 
  the 
  early 
  age 
  of 
  forty 
  years. 
  His 
  works 
  on 
  the 
  "Theory 
  of 
  

   Light" 
  (1890) 
  and 
  the 
  "Theory 
  of 
  Heat" 
  (1895) 
  gave 
  him 
  a 
  

   high 
  place 
  among 
  writers 
  in 
  Physics, 
  while 
  his 
  papers, 
  following 
  

   Zeeman, 
  on 
  radiation 
  phenomena 
  in 
  a 
  magnetic 
  field 
  (1897, 
  1899) 
  

   showed 
  that 
  he 
  was 
  an 
  investigator 
  of 
  a 
  high 
  order. 
  

  

  Mr. 
  George 
  James 
  Symons, 
  the 
  well 
  known 
  English 
  meteor- 
  

   ologist, 
  died 
  on 
  March 
  10, 
  at 
  the 
  age 
  of 
  sixty-two. 
  

  

  Dr. 
  St. 
  George 
  Mivart, 
  the 
  distinguished 
  English 
  biologist, 
  

   died 
  on 
  April 
  1st 
  at 
  the 
  age 
  of 
  seventy-three. 
  Some 
  of 
  his 
  promi- 
  

   nent 
  works 
  are: 
  "On 
  the 
  Genesis 
  of 
  Species" 
  (1871); 
  "Lessons 
  

   in 
  Elementary 
  Anatomy" 
  (1873) 
  ; 
  " 
  Nature 
  and 
  Thought" 
  (1882). 
  

  

  Dr. 
  Wilhelm 
  Waagex, 
  Professor 
  of 
  Paleontology 
  at 
  the 
  

   University 
  of 
  Vienna, 
  died 
  on 
  March 
  24 
  in 
  his 
  fifty-ninth 
  year. 
  

  

  Professor 
  Emile 
  Btaxciiard, 
  the 
  celebrated 
  French 
  zoologist, 
  

   died 
  at 
  Paris 
  in 
  February 
  at 
  the 
  age 
  of 
  eighty-four. 
  

  

  