﻿256 
  Intelligence 
  and 
  Miscellaneous 
  Articles. 
  

  

  Die 
  Partiellen 
  Differ 
  ential-Gleichung 
  en 
  der 
  Mathematischen 
  Physik. 
  

   jNach 
  liiemann's 
  Vorlesungen 
  in 
  vierter 
  Auflage 
  neu 
  bearbeitet 
  

   von 
  Heusrich 
  Webeb, 
  Professor 
  der 
  Mathematik 
  an 
  der 
  

   Universitat 
  Strassburg. 
  Zweiter 
  Band. 
  Mit 
  eingedruckten 
  

   Abbildungen. 
  Braunschweig: 
  E. 
  Vieweg 
  und 
  Sofia. 
  1901. 
  

   Pp. 
  xii 
  + 
  527. 
  

  

  It 
  is 
  not 
  very 
  long 
  since 
  we 
  had 
  occasion 
  to 
  notice 
  the 
  first 
  

   volume 
  of 
  this 
  highly 
  important 
  work 
  on 
  mathematical 
  physics. 
  

   The 
  second 
  volume 
  has 
  now 
  made 
  its 
  appearance, 
  and 
  fully 
  

   maintains 
  the 
  high 
  standard 
  of 
  excellence 
  of 
  its 
  predecessor. 
  It 
  

   is 
  divided 
  into 
  five 
  sections. 
  Section 
  I. 
  is 
  purely 
  mathematical, 
  

   and 
  contains 
  a 
  succinct 
  account 
  of 
  that 
  portion 
  of 
  the 
  theory 
  of 
  

   linear 
  differential 
  equations 
  which 
  is 
  of 
  importance 
  in 
  connexion 
  

   with 
  physical 
  applications. 
  Section 
  II. 
  deals 
  with 
  the 
  theory 
  of 
  

   heat 
  conduction. 
  Section 
  III. 
  is 
  devoted 
  to 
  the 
  theory 
  of 
  elasticity, 
  

   and 
  includes 
  a 
  brief 
  general 
  account 
  of 
  elasticity, 
  statical 
  elastic 
  

   problems, 
  and 
  the 
  vibrations 
  of 
  strings 
  and 
  plates. 
  Section 
  IV. 
  

   is 
  on 
  electrical 
  oscillations, 
  and 
  deals 
  with 
  electromagnetic 
  waves, 
  

   the 
  propagation 
  of 
  current 
  along 
  a 
  cable, 
  and 
  the 
  reflexion 
  of 
  

   electromagnetic 
  waves. 
  The 
  concluding 
  Section 
  V. 
  is 
  devoted 
  to 
  

   Hydrodynamics. 
  

  

  To 
  the 
  student 
  of 
  mathematical 
  physics 
  the 
  completed 
  work 
  will 
  

   be 
  one 
  of 
  exceptional 
  value 
  and 
  interest. 
  

  

  XXVIII. 
  Intelligence 
  and 
  Miscellaneous 
  Article*. 
  

  

  THE 
  MICHELSON-MORLEY 
  EXPERIMENT. 
  

  

  Dunheved, 
  Endcliffe 
  Crescent, 
  

   Sheffield 
  

   January 
  9, 
  1902. 
  

  

  To 
  the 
  Editors 
  of 
  the 
  Philosophical 
  Magazine. 
  

   Gentlemen, 
  — 
  

   TV/MTH 
  reference 
  to 
  my 
  remark 
  in 
  the 
  second 
  paragraph 
  on 
  

   *^ 
  page 
  38 
  of 
  the 
  last 
  number 
  of 
  the 
  Philosophical 
  Magazine, 
  

   I 
  learn 
  from 
  Prof. 
  Morley 
  that 
  although 
  the 
  observations 
  were 
  

   taken 
  in 
  reverse 
  order, 
  the 
  results 
  were 
  printed 
  in 
  direct. 
  As 
  he 
  

   remarks, 
  the 
  curves 
  would 
  therefore 
  show 
  either 
  that 
  the 
  maximum 
  

   drift 
  took 
  place 
  about 
  3 
  p.m., 
  or 
  that 
  they 
  were 
  due 
  to 
  instrumental 
  

   errors. 
  

  

  Whatever 
  may 
  be 
  the 
  cause, 
  it 
  may 
  be 
  noted 
  that 
  if, 
  as 
  the 
  

   latest 
  authorities 
  say, 
  Vega 
  is 
  the 
  apex 
  of 
  the 
  sun's 
  way, 
  and 
  

   the 
  sun's 
  proper 
  motion 
  is 
  15 
  miles 
  per 
  second, 
  then 
  on 
  July 
  8, 
  

   the 
  resultant 
  velocity 
  of 
  the 
  earth 
  would 
  give 
  at 
  Cleveland, 
  Ohio 
  

   (lat. 
  42° 
  JN".), 
  a 
  maximum 
  drift 
  at 
  about 
  7.45 
  p.m. 
  

  

  I 
  am, 
  Tours 
  faithfully, 
  

  

  W. 
  M. 
  Hicks. 
  

  

  