﻿420 
  Scientific 
  Intelligence. 
  

  

  the 
  direction 
  of 
  the 
  rays 
  ; 
  uniaxial 
  crystals 
  ; 
  double 
  refraction 
  at 
  

   the 
  surface 
  of 
  a 
  crystal 
  ; 
  and 
  double 
  refraction 
  in 
  uniaxial 
  crys- 
  

   tals, 
  all 
  of 
  which 
  are 
  contained 
  in 
  thirty-seven 
  pages. 
  The 
  chap- 
  

   ter 
  which 
  precedes 
  this 
  treats 
  somewhat 
  compendiously 
  of 
  elec- 
  

   trical 
  oscillations 
  in 
  a 
  space 
  of 
  less 
  than 
  fifteen 
  pages. 
  It 
  is 
  clear 
  

   that 
  a 
  student 
  can 
  hardly 
  be 
  expected 
  to 
  master 
  these 
  portions 
  of 
  

   mathematical 
  physics 
  with 
  no 
  other 
  help, 
  but, 
  on 
  the 
  other 
  hand, 
  

   as 
  an 
  aid 
  in 
  coordinating 
  his 
  knowledge 
  and 
  as 
  a 
  guide 
  in 
  the 
  

   choice 
  of 
  a 
  rational 
  and 
  consistent 
  system 
  of 
  notation 
  the 
  book 
  is 
  

   of 
  very 
  great 
  value. 
  

  

  7. 
  Theory 
  of 
  Physics 
  ; 
  by 
  Joseph 
  S. 
  Ames, 
  Ph.D., 
  pp. 
  xvii 
  

   + 
  513. 
  New 
  York, 
  1897. 
  (Harper 
  & 
  Bros.) 
  — 
  As 
  stated 
  in 
  the 
  

   author's 
  preface, 
  this 
  book 
  is 
  designed 
  for 
  use 
  as 
  a 
  text-book 
  by 
  

   college 
  classes 
  in 
  elementary 
  physics 
  in 
  connection 
  with 
  a 
  course 
  

   of 
  experimental 
  lectures 
  and 
  recitations. 
  The 
  methods 
  of 
  presen- 
  

   tation 
  are 
  clear, 
  the 
  arrangement 
  logical 
  and, 
  as 
  a 
  whole, 
  the 
  book 
  

   seems 
  well 
  adapted 
  to 
  its 
  purpose. 
  The 
  portion 
  dealing 
  with 
  

   mechanics 
  is 
  especially 
  to 
  be 
  commended 
  ; 
  the 
  definitions 
  are 
  con- 
  

   sistent 
  and 
  philosophical, 
  and 
  the 
  way 
  in 
  which 
  the 
  analogies 
  

   between 
  translation 
  and 
  rotation 
  are 
  brought 
  out 
  and 
  insisted 
  

   upon 
  is 
  admirable. 
  

  

  The 
  section 
  upon 
  electricity 
  and 
  magnetism 
  is 
  largely 
  written 
  

   from 
  the 
  Faraday-Maxwell 
  point 
  of 
  view, 
  and 
  the 
  ether 
  is 
  fre- 
  

   quently 
  referred 
  to 
  as 
  the 
  medium 
  of 
  electrical 
  actions; 
  it 
  seems 
  

   strange, 
  however, 
  to 
  find 
  no 
  mention 
  made 
  of 
  the 
  sole 
  ground 
  for 
  

   this 
  belief; 
  viz. 
  the 
  entire 
  similarity 
  between 
  light 
  and 
  electro- 
  

   dynamic 
  action. 
  So 
  great 
  a 
  generalization 
  would 
  seem 
  to 
  merit 
  

   some 
  discussion 
  even 
  in 
  an 
  elementary 
  text-book, 
  published 
  

   twenty-five 
  years 
  after 
  Maxwell 
  and 
  nearly 
  ten 
  years 
  after 
  Hertz. 
  

  

  Problems 
  in 
  the 
  reflection 
  and 
  refraction 
  of 
  light 
  are 
  mostly 
  

   treated 
  by 
  considering 
  wave 
  surfaces 
  and 
  their 
  curvatures 
  instead 
  

   of 
  rays 
  and 
  focal 
  lengths. 
  This 
  treatment 
  is 
  much 
  to 
  be 
  pre- 
  

   ferred, 
  not 
  only 
  because 
  of 
  its 
  direct 
  reference 
  to 
  the 
  nature 
  of 
  

   light, 
  but 
  also 
  because 
  it 
  leads 
  to 
  methods 
  of 
  much 
  greater 
  

   elegance 
  and 
  power 
  in 
  the 
  solution 
  of 
  complicated 
  optical 
  

   problems. 
  

  

  The 
  work, 
  as 
  a 
  whole, 
  is 
  a 
  decided 
  improvement 
  upon 
  the 
  

   ordinary 
  text-books 
  of 
  elementary 
  physics 
  and 
  will 
  no 
  doubt 
  be 
  

   welcomed 
  by 
  teachers 
  of 
  that 
  subject. 
  h. 
  a. 
  b. 
  

  

  8. 
  The 
  Outlines 
  of 
  Physics, 
  an 
  Elementary 
  Text- 
  Bo 
  ok 
  ; 
  by 
  

   E. 
  L. 
  Nichols, 
  pp. 
  452, 
  New 
  York, 
  1897, 
  (The 
  Macmillan 
  

   Company.) 
  — 
  This 
  is 
  an 
  elementary 
  treatise 
  for 
  use 
  in 
  preparatory 
  

   schools. 
  It 
  aims 
  to 
  combine 
  in 
  one 
  volume 
  the 
  laboratory 
  manual 
  

   and 
  the 
  text-book, 
  being 
  intended 
  for 
  a 
  one 
  year's 
  course. 
  The 
  

   best 
  feature 
  of 
  the 
  book 
  is 
  that 
  part 
  devoted 
  to 
  the 
  laboratory 
  

   directions. 
  There 
  are 
  above 
  a 
  hundred 
  experiments, 
  carefully 
  

   worked 
  out 
  and 
  explained, 
  the 
  apparatus 
  used 
  being 
  simple 
  and 
  

   inexpensive. 
  The 
  emphasis 
  laid 
  on 
  the 
  tabulation 
  and 
  interpreta- 
  

   tion 
  of 
  the 
  quantitative 
  results, 
  whenever 
  obtained, 
  is 
  very 
  wel- 
  

   come, 
  on 
  account 
  of 
  its 
  conspicuous 
  absence 
  in 
  most 
  elementary 
  

  

  