﻿Chemistry 
  and 
  Physics. 
  229 
  

  

  In 
  the 
  earlier 
  chapters 
  the 
  subject-matter 
  is 
  presented 
  in 
  great 
  

   detail 
  and 
  in 
  a 
  very 
  elementary 
  manner. 
  In 
  addition 
  to 
  line 
  

   diagrams, 
  four 
  full-page, 
  half-tone 
  reproductions 
  of 
  photo- 
  

   graphs, 
  illustrating 
  various 
  phases 
  of 
  reflection 
  in 
  one 
  or 
  more 
  

   plane 
  mirrors, 
  are 
  given. 
  The 
  subject 
  of 
  reflection 
  is 
  immediately 
  

   followed 
  by 
  chapters 
  on 
  refraction 
  at 
  plane 
  surfaces, 
  such 
  as 
  

   slabs 
  and 
  prisms. 
  In 
  particular, 
  the 
  power 
  of 
  an 
  ophthalmic 
  

   prism, 
  and 
  the 
  definition 
  and 
  use 
  of 
  each 
  of 
  the 
  terms 
  "centrad" 
  

   and 
  "prisru-dioptry" 
  are 
  discussed. 
  The 
  topics 
  of 
  reflection 
  

   and 
  refraction 
  of 
  paraxial 
  rays 
  at 
  spherical 
  surfaces 
  are 
  next 
  

   introduced 
  as 
  appropriate 
  introductions 
  to 
  the 
  discussions 
  of 
  

   thin 
  lenses, 
  changes 
  of 
  curvature 
  of 
  wave-fronts, 
  astigmatic 
  

   lenses, 
  symmetrical 
  optical 
  instruments, 
  compound 
  systems, 
  

   thick 
  lenses 
  and 
  combinations 
  of 
  lenses 
  and 
  mirrors, 
  etc. 
  Chap- 
  

   ter 
  XIII 
  deals 
  with 
  the 
  optical 
  system 
  of 
  the 
  human 
  eye 
  and 
  

   with 
  the 
  magnifying 
  power 
  of 
  optical 
  instruments. 
  The 
  next 
  

   chapter 
  relates 
  to 
  dispersion 
  and 
  achromatism. 
  The 
  last 
  

   chapter 
  (XV) 
  pertains 
  to 
  rays 
  of 
  finite 
  -slope, 
  to 
  spherical 
  

   aberration, 
  to 
  astigmatism 
  of 
  oblique 
  bundles, 
  etc. 
  

  

  Throughout 
  the 
  text 
  the 
  author 
  has 
  paid 
  attention 
  to 
  the 
  

   practical 
  applications 
  of 
  the 
  general 
  principles. 
  For 
  example, 
  

   adequate 
  space 
  is 
  devoted 
  to 
  the 
  heliostat, 
  Hadley's 
  sextant, 
  the 
  

   lens-gauge, 
  toric 
  lenses, 
  ametropia, 
  emmetropia, 
  correction 
  lenses, 
  

   etc. 
  One 
  of 
  the 
  needs 
  of 
  the 
  student 
  is 
  met 
  by 
  the 
  large 
  number 
  

   ( 
  440 
  ) 
  of 
  problems 
  which 
  are 
  collected 
  at 
  the 
  ends 
  of 
  the 
  chapters. 
  

   The 
  same 
  high 
  standard 
  which 
  was 
  set 
  in 
  the 
  earlier 
  volume 
  has 
  

   been 
  fully 
  maintained 
  in 
  all 
  respects, 
  so 
  that 
  the 
  book 
  removes 
  

   one 
  of 
  the 
  causes 
  which 
  may 
  have 
  militated 
  against 
  the 
  offering 
  

   of 
  courses 
  on 
  geometrical 
  optics 
  in 
  American 
  colleges 
  and 
  

   universities. 
  h. 
  s. 
  u. 
  

  

  10. 
  Physics 
  for 
  Technical 
  Students. 
  Sound, 
  Light, 
  Elec- 
  

   tric 
  it 
  ij 
  and 
  Magnetism; 
  bv 
  William 
  Ballantyne 
  Anderson. 
  

   Pp. 
  xiii, 
  458 
  ; 
  373 
  figures. 
  New 
  York, 
  1919 
  (McGraw-Hill 
  Book 
  

   Co.). 
  — 
  This 
  volume 
  constitutes 
  the 
  second 
  part 
  of 
  "Physics 
  for 
  

   Technical 
  Students," 
  the 
  first 
  part 
  having 
  been 
  published 
  in 
  

   the 
  year 
  1914 
  (see 
  37, 
  480, 
  1914). 
  It 
  commences 
  with 
  chapter 
  

   XIX, 
  page 
  337, 
  and 
  it 
  is 
  subdivided 
  into: 
  Part 
  IV, 
  Sound 
  (55 
  

   pages, 
  25 
  problems). 
  Part 
  V, 
  Light 
  (154 
  pages, 
  45 
  problems), 
  

   and 
  Part 
  YI, 
  Electricity 
  and 
  Magnetism 
  (230 
  pages, 
  .87 
  

   problems). 
  "Material, 
  which 
  in 
  the 
  author's 
  opinion 
  might 
  

   be 
  omitted 
  in 
  a 
  briefer 
  course, 
  appears 
  in 
  finer 
  print. 
  ' 
  ' 
  Stress 
  is 
  

   laid 
  on 
  the 
  practical 
  applications 
  of 
  the 
  subjects 
  discussed 
  

   because 
  the 
  text 
  is 
  designed 
  primarily 
  to 
  meet 
  the 
  needs 
  of 
  

   classes 
  in 
  Agriculture 
  and 
  Engineering. 
  The 
  two 
  volumes 
  may 
  

   be 
  obtained 
  bound 
  in 
  one. 
  

  

  Taken 
  as 
  a 
  whole, 
  the 
  present 
  volume 
  possesses 
  all 
  the 
  desir- 
  

   able 
  features 
  that 
  characterized 
  the 
  companion 
  volume 
  and 
  

   which 
  caused 
  the 
  earlier 
  part 
  to 
  meet 
  with 
  no 
  small 
  measure 
  of 
  

  

  Am. 
  Jour. 
  Sci.— 
  Fourth 
  Series, 
  Vol. 
  XLVII, 
  No. 
  279.— 
  March, 
  1919. 
  

   16 
  

  

  