﻿340 
  James 
  D 
  ) 
  wight 
  Dana. 
  

  

  of 
  the 
  facts 
  of 
  the 
  science 
  but 
  a 
  development 
  of 
  the 
  whole 
  sub- 
  

   ject 
  with 
  a 
  breadth, 
  philosophy 
  and 
  originality 
  of 
  treatment 
  that 
  

   has 
  seldom 
  been 
  attempted. 
  One 
  of 
  his 
  colleagues 
  remarks 
  : 
  

  

  ".The 
  treatment 
  of 
  strata 
  and 
  fossils 
  from 
  a 
  chronological 
  point 
  

   of 
  view 
  as 
  Historical 
  Geology 
  is 
  a 
  characteristic 
  feature 
  of 
  his 
  

   Manual. 
  The 
  growth 
  and 
  development 
  of 
  the 
  earth, 
  its 
  conti- 
  

   nents 
  and 
  seas 
  and 
  the 
  progress 
  in 
  the 
  organic 
  life 
  on 
  its 
  sur- 
  

   face, 
  were 
  thus 
  unified 
  into 
  a 
  special 
  department 
  of 
  Geology, 
  

   the 
  history 
  of 
  the 
  earth 
  and 
  of 
  its 
  inhabitants, 
  which 
  was 
  by 
  

   other 
  authors 
  dealt 
  with 
  as 
  formational, 
  stratigraphic 
  or 
  

   paleontologic 
  geology." 
  

  

  Each 
  edition 
  of 
  the 
  Geology 
  was 
  carefully 
  worked 
  over 
  and 
  

   the 
  last 
  was 
  completely 
  rewritten 
  from 
  beginning 
  to 
  end. 
  It 
  

   was 
  a 
  great 
  pleasure 
  to 
  him 
  in 
  connection 
  with 
  this 
  work 
  to 
  

   have 
  the 
  constant 
  and 
  ready 
  cooperation 
  of 
  a 
  number 
  of 
  the 
  

   able 
  young 
  geologists 
  in 
  the 
  country, 
  without 
  whose 
  aid 
  the 
  

   volume 
  could 
  not 
  have 
  been 
  so 
  satisfactorily 
  completed. 
  Simi- 
  

   lar 
  cooperation 
  and 
  pleasant 
  relations 
  he 
  had 
  enjoyed 
  while 
  at 
  

   work 
  upon 
  his 
  earlier 
  volumes 
  both 
  in 
  Geology 
  and 
  Miner- 
  

   alogy, 
  but 
  this 
  is 
  hardly 
  the 
  place 
  to 
  speak 
  of 
  that 
  in 
  detail. 
  

   Allusion 
  has 
  also 
  been 
  made 
  to 
  the 
  smaller 
  works, 
  the 
  Text 
  

   Book 
  (first 
  edition, 
  1864,) 
  and 
  the 
  Geological 
  Story 
  (1875) 
  ; 
  of 
  

   the 
  last 
  the 
  manuscript 
  of 
  a 
  new 
  edition 
  is 
  now 
  in 
  the 
  printers' 
  

   hands. 
  

  

  In 
  the 
  general 
  department 
  of 
  Geology 
  his 
  contributions 
  again 
  

   were 
  largely 
  to 
  subjects 
  of 
  a 
  broad 
  and 
  philosophical 
  character 
  : 
  

   the 
  origin 
  of 
  continents 
  and 
  of 
  the 
  grand 
  features 
  of 
  the 
  earth 
  

   was 
  discussed 
  in 
  early 
  papers 
  as 
  well 
  as 
  later 
  ; 
  the 
  problems 
  of 
  

   mountain-making 
  and 
  the 
  phenomena 
  of 
  volcanic 
  action, 
  to 
  

   which 
  he 
  devoted 
  much 
  thought, 
  are 
  some 
  of 
  the 
  other 
  topics 
  

   treated 
  at 
  length. 
  

  

  But, 
  as 
  a 
  geologist, 
  he 
  was 
  not 
  only 
  a 
  thinker 
  and 
  writer 
  in 
  

   his 
  study 
  but 
  also 
  an 
  active 
  observer 
  in 
  the 
  field. 
  This 
  

   remark 
  applies 
  obviously 
  to 
  the 
  four 
  years 
  with 
  the 
  Exploring 
  

   Expedition 
  but 
  further 
  particularly 
  to 
  the 
  period 
  from 
  1872 
  to 
  

   1887, 
  when 
  he 
  was 
  carrying 
  on 
  the 
  study 
  of 
  the 
  crystalline 
  

   rocks 
  of 
  the 
  so-called 
  Taconic 
  system 
  chiefly 
  in 
  western 
  New 
  

   England 
  ; 
  also 
  of 
  the 
  glacial 
  phenomena 
  of 
  southern 
  New 
  Eng- 
  

   land 
  (1870 
  et 
  seq.) 
  The 
  region 
  included 
  in 
  western 
  Connec- 
  

  

  