﻿416 
  Scientific 
  Intelligence. 
  

  

  interest 
  of 
  young 
  students 
  in 
  further 
  mathematical 
  inquiries." 
  

   The 
  material 
  selected 
  is 
  of 
  such 
  a 
  heterogeneous 
  character 
  as 
  to 
  be 
  

   susceptible 
  only 
  of 
  the 
  following 
  very 
  broad 
  classification: 
  arithme- 
  

   tic, 
  algebra, 
  geometry, 
  trigonometry, 
  analytic 
  geometry, 
  calculus, 
  

   astronomy 
  and 
  the 
  calendar, 
  mechanics, 
  and 
  physics. 
  The 
  num- 
  

   ber 
  of 
  "recreations" 
  is 
  180. 
  These 
  include 
  puzzles, 
  paradoxes, 
  

   fallacies, 
  historical 
  memoranda, 
  and 
  serious 
  remarks 
  introductory 
  

   to 
  the 
  study 
  of 
  the 
  more 
  advanced 
  subjects. 
  

  

  Taken 
  as 
  a 
  whole 
  the 
  book 
  should 
  be 
  found 
  both 
  interesting 
  

   and 
  instructive 
  by 
  those 
  to 
  whom 
  it 
  is 
  addressed. 
  In 
  two 
  articles, 
  

   however, 
  the 
  author 
  makes 
  statements 
  which 
  are 
  either 
  open 
  to 
  

   very 
  serious 
  objection 
  or 
  are 
  altogether 
  incorrect. 
  In 
  section 
  137 
  

   he 
  concludes 
  that 
  mechanics 
  ought 
  to 
  be 
  omitted 
  from 
  courses 
  in 
  

   physics 
  because 
  the 
  teacher 
  of 
  pure 
  science 
  makes 
  use 
  of 
  dynes 
  

   and 
  poundals 
  and 
  since 
  " 
  ... 
  no 
  apparatus 
  for 
  measuring 
  forces 
  

   in 
  such 
  units 
  has 
  ever 
  been 
  made 
  or 
  used." 
  Article 
  138 
  contains 
  

   several 
  statements 
  which 
  are 
  unqualifiedly 
  wrong. 
  For 
  example, 
  

   the 
  unit 
  of 
  acceleration 
  is 
  given 
  as 
  " 
  one 
  unit 
  of 
  length 
  per 
  sec- 
  

   ond." 
  With 
  regard 
  to 
  the 
  dimensional 
  equation 
  [F] 
  = 
  [M 
  L 
  2 
  T_2 
  ] 
  

   he 
  writes 
  : 
  " 
  The 
  student 
  tries 
  hard 
  to 
  comprehend 
  this, 
  but 
  finds 
  

   it 
  impossible, 
  for 
  he 
  knows 
  that 
  force 
  is 
  not 
  M.L./T 
  2 
  and 
  he 
  

   knows 
  that 
  there 
  is 
  no 
  way 
  to 
  measure 
  a 
  force 
  except 
  by 
  the 
  

   number 
  of 
  units 
  of 
  force 
  which 
  it 
  contains. 
  The 
  truth 
  of 
  the 
  

   matter 
  is 
  that 
  the 
  equation 
  F 
  — 
  mf 
  is 
  not 
  true." 
  h. 
  s. 
  u. 
  

  

  II. 
  Geology 
  and 
  Mineralogy. 
  

  

  1. 
  The 
  Andes 
  of 
  Southern 
  Peru 
  ; 
  by 
  Isaiah 
  Bowman, 
  

   Director 
  of 
  the 
  American 
  Geographical 
  Society. 
  Pp. 
  xi, 
  336, 
  with 
  

   204 
  figures 
  and 
  7 
  topographic 
  sheets. 
  New 
  York, 
  1916 
  (Henry 
  

   Holt 
  and 
  Compan} 
  7 
  ). 
  — 
  The 
  attractively 
  printed 
  and 
  beautifully 
  

   illustrated 
  " 
  Andes 
  of 
  Southern 
  Peru 
  " 
  is 
  essentially 
  the 
  record 
  of 
  

   a 
  reconnaissance 
  along 
  the 
  seventy-third 
  meridian, 
  between 
  par- 
  

   allels 
  of 
  latitude 
  12° 
  and 
  16° 
  37' 
  south. 
  The 
  book 
  consists 
  of 
  

   two 
  parts. 
  In 
  Part 
  I, 
  Dr. 
  Bowman 
  gives 
  a 
  well-composed 
  picture 
  

   of 
  the 
  life 
  of 
  the 
  people, 
  in 
  which 
  the 
  factor 
  of 
  environment 
  is 
  

   emphasized. 
  After 
  reading 
  the 
  chapters 
  on 
  The 
  Canyons 
  of 
  the 
  

   Urubamba, 
  The 
  Rubber 
  Forests, 
  The 
  Forest 
  Indians, 
  The 
  

   Country 
  of 
  the 
  Shepherds, 
  and 
  The 
  Border 
  Valleys 
  of 
  the 
  Eastern 
  

   Andes, 
  one 
  feels 
  that 
  he 
  knows 
  both 
  the 
  Indians 
  and 
  the 
  Spanish 
  

   planters. 
  Two 
  chapters 
  on 
  climate 
  record 
  and 
  discuss 
  the 
  sig- 
  

   nificance 
  of 
  observations 
  made 
  by 
  the 
  Yale 
  Peruvian 
  Expedi- 
  

   tions, 
  the 
  Harvard 
  Observatory, 
  the 
  Peruvian 
  Government, 
  and 
  

   the 
  Geographical 
  Society 
  of 
  Lima. 
  

  

  The 
  Physiography 
  of 
  the 
  Peruvian 
  Andes 
  is 
  treated 
  under 
  the 
  

   headings: 
  The 
  Peruvian 
  Landscape, 
  The 
  Western 
  Andes, 
  The 
  

   Eastern 
  Andes, 
  The 
  Coastal 
  Terraces, 
  Physiographic 
  and 
  Geo- 
  

   logic 
  Development, 
  and 
  Glacial 
  Features. 
  The 
  most 
  significant 
  

  

  