﻿Geology 
  and 
  Natural 
  History. 
  423 
  

  

  us 
  an 
  admirable 
  class 
  book 
  in 
  geology, 
  which 
  has 
  enough 
  of 
  detail 
  

   and 
  not 
  too 
  much 
  for 
  the 
  ordinary 
  college 
  student. 
  In 
  general 
  

   the 
  subject 
  has 
  been 
  developed 
  with 
  much 
  skill 
  and 
  a 
  good 
  sense 
  

   of 
  proportion, 
  though 
  in 
  abbreviating 
  the 
  treatment 
  too 
  much 
  has 
  

   been 
  omitted 
  in 
  some 
  cases. 
  For 
  instance, 
  geysers 
  are 
  dismissed 
  

   with 
  only 
  ten 
  lines, 
  and 
  discussed 
  quite 
  separate 
  from 
  the 
  chap- 
  

   ter 
  on 
  volcanoes, 
  under 
  the 
  general 
  subject 
  of 
  " 
  running 
  waters." 
  

  

  The 
  subjects 
  are 
  treated 
  in 
  chapters, 
  each 
  one 
  of 
  which 
  can 
  be 
  

   studied 
  by 
  itself, 
  and, 
  in 
  general, 
  sufficient 
  definiteness 
  of 
  state- 
  

   ment 
  is 
  given 
  to 
  enable 
  the 
  student 
  to 
  form 
  correct 
  notions 
  of 
  the 
  

   topics 
  discussed 
  ; 
  but 
  to 
  the 
  writer 
  the 
  arrangement 
  seems 
  too 
  

   discontinuous 
  for 
  the 
  best 
  interests 
  of 
  a 
  class, 
  unless 
  it 
  be 
  used 
  to 
  

   supplement 
  a 
  course 
  of 
  lectures 
  in 
  which 
  the 
  personality 
  of 
  the 
  

   instructor 
  appears. 
  A 
  want 
  of 
  continuity 
  of 
  treatment 
  is 
  felt, 
  for 
  

   instance, 
  in 
  the 
  discussion 
  of 
  glaciers; 
  thus 
  on 
  pp. 
  104-116, 
  as 
  

   one 
  of 
  the 
  destructive 
  processes 
  ; 
  ice 
  deposits 
  are 
  considered 
  again, 
  

   pp. 
  153-159, 
  as 
  reconstructive 
  processes, 
  and 
  ice 
  erosion 
  is 
  dis- 
  

   cussed 
  again 
  on 
  pages 
  310-312. 
  Again, 
  the 
  separation 
  of 
  the 
  

   chapters 
  on 
  land 
  sculpture, 
  adjustment 
  of 
  rivers 
  aud 
  cycles 
  of 
  

   erosion, 
  quite 
  distant 
  from 
  the 
  destructive 
  and 
  reconstructive 
  

   processes 
  of 
  dynamical 
  geology, 
  makes 
  a 
  break 
  in 
  continuity, 
  

   which 
  is 
  useful 
  in 
  an 
  exhaustive 
  treatise 
  on 
  geology, 
  but 
  appears 
  

   somewhat 
  artificial 
  in 
  an 
  introduction 
  to 
  the 
  subject. 
  

  

  The 
  illustrations 
  of 
  the 
  book 
  are 
  chiefly 
  new, 
  fresh 
  and 
  from 
  

   American 
  sources, 
  in 
  this 
  particular 
  making 
  the 
  book 
  a 
  decided 
  

   addition 
  to 
  text-book 
  literature. 
  A 
  number 
  of 
  excellent 
  photo- 
  

   graphs 
  of 
  typical 
  regions 
  and 
  structures 
  are 
  rej^roduced, 
  many 
  of 
  

   them 
  admirably, 
  but 
  this 
  method 
  of 
  reproduction 
  has 
  its 
  limita- 
  

   tions, 
  such 
  pictures 
  as 
  those 
  of 
  Mauna 
  Loa 
  and 
  Mt. 
  Shasta 
  and 
  

   some 
  others 
  (as 
  figures 
  34, 
  120, 
  128) 
  are 
  too 
  indistinct 
  to 
  have 
  

   much 
  scientific 
  value. 
  h. 
  s. 
  w. 
  

  

  4. 
  Glaciers 
  of 
  North 
  America. 
  A 
  Reading 
  Lesson 
  for 
  Students 
  

   of 
  Geography 
  and 
  Geology; 
  by 
  Iseael 
  C. 
  Russell, 
  pp. 
  210, 
  

   Boston 
  and 
  London, 
  1897. 
  (Ginn 
  & 
  Oo.) 
  — 
  It 
  is 
  not 
  many 
  years 
  

   now 
  since 
  very 
  little 
  was 
  known 
  of 
  glaciers 
  on 
  this 
  continent, 
  

   except 
  those 
  of 
  the 
  Greenland 
  coast 
  in 
  the 
  far 
  north. 
  Recent 
  

   exploralions, 
  however, 
  have 
  shown 
  that 
  there 
  are 
  true 
  glaciers 
  

   even 
  in 
  the 
  Sierras 
  of 
  California, 
  while 
  those 
  of 
  Alaska 
  have 
  been 
  

   extensively 
  studied. 
  In 
  this 
  work, 
  particularly 
  in 
  the 
  latter 
  field, 
  

   the 
  author 
  has 
  done 
  much 
  himself, 
  and 
  the 
  present 
  volume 
  is 
  a 
  

   very 
  interesting 
  summary 
  of 
  the 
  entire 
  subject, 
  which 
  will 
  appeal 
  

   to 
  the 
  popular 
  reader 
  as 
  well 
  as 
  to 
  those 
  interested 
  in 
  the 
  strictly 
  

   scientific 
  side. 
  Of 
  the 
  concluding 
  chapters, 
  one 
  discusses 
  the 
  

   various 
  hypotheses 
  advanced 
  to 
  account 
  for 
  the 
  movement 
  of 
  

   glaciers, 
  and 
  another 
  treats 
  of 
  the 
  subject 
  of 
  the 
  life-history 
  of 
  a 
  

   glacier. 
  

  

  The 
  book 
  is 
  admirably 
  illustrated 
  and 
  the 
  half-tone 
  reproduc- 
  

   tions 
  from 
  photographs 
  add 
  much 
  to 
  its 
  interest 
  and 
  value. 
  

  

  5. 
  A 
  Treatise 
  on 
  Rocks, 
  Rock- 
  Weathering 
  and 
  Soils; 
  by 
  George 
  

   P. 
  Merrill, 
  pp. 
  411. 
  New 
  York 
  and 
  London, 
  1897. 
  (The 
  Mac- 
  

  

  Am. 
  Jour. 
  Sol— 
  Fourth 
  Series, 
  Yol. 
  Ill, 
  No. 
  17.— 
  Mat. 
  1897 
  

   29 
  

  

  