﻿Geology 
  and 
  Natural 
  History. 
  387 
  

  

  issued 
  on 
  the 
  1st 
  of 
  October. 
  This 
  new 
  periodical 
  is 
  to 
  be 
  con- 
  

   ducted 
  by 
  Dr. 
  E. 
  Riecke 
  and 
  Dr. 
  H. 
  Tti. 
  Simon 
  of 
  Gottingen, 
  

   aided 
  by 
  a 
  considerable 
  staff 
  of 
  co-workers, 
  for 
  tlie 
  preparation 
  

   of 
  abstracts. 
  It 
  is 
  to 
  be 
  issued 
  in 
  weekly 
  numbers 
  at 
  a 
  cost 
  of 
  5 
  

   marks 
  for 
  three 
  months. 
  As 
  a 
  prompt 
  means 
  by 
  which 
  physi- 
  

   cists 
  may 
  present 
  the 
  results 
  of 
  their 
  work, 
  it 
  will 
  doubtless 
  

   prove 
  of 
  great 
  value 
  and 
  contribute 
  much 
  to 
  the 
  progress 
  of 
  

   science. 
  The 
  portion 
  devoted 
  to 
  abstracts 
  and 
  book 
  notices 
  also 
  

   promises 
  to 
  be 
  carefully 
  and 
  thoroughly 
  conducted. 
  

  

  II. 
  Geology 
  and 
  I^atueal 
  History. 
  

  

  1. 
  On 
  Geological 
  Time. 
  — 
  The 
  address 
  of 
  Sir 
  Aechibald 
  Geikie, 
  

   before 
  the 
  Geological 
  Section 
  of 
  the 
  British 
  Association 
  at 
  the 
  

   recent 
  Dover 
  meeting, 
  was 
  an 
  able 
  presentation 
  of 
  the 
  profound 
  

   problem 
  of 
  geological 
  time. 
  He 
  opened 
  with 
  a 
  historical 
  sum- 
  

   mary 
  of 
  the 
  successive 
  phases 
  of 
  the 
  discussion, 
  beginning 
  with 
  

   the 
  writings 
  of 
  Hutton, 
  to 
  whom 
  modern 
  geology 
  owes 
  so 
  much. 
  

   The 
  conclusion 
  of 
  Button's 
  philosophy 
  is 
  thus 
  stated, 
  "that 
  the 
  

   history 
  of 
  the 
  earth 
  occupied 
  prolonged 
  though 
  indeterminate 
  

   ages 
  in 
  its 
  accomplishment." 
  The 
  Uniformitarian 
  School, 
  follow- 
  

   ing, 
  founded 
  on 
  the 
  teachings 
  of 
  Hutton 
  and 
  Play 
  fair, 
  came 
  to 
  

   believe 
  that 
  an 
  absolutely 
  unlimited 
  extent 
  of 
  time 
  was 
  at 
  the 
  dis- 
  

   posal 
  of 
  geologists. 
  In 
  1862, 
  however, 
  the 
  discussion 
  of 
  the 
  sub- 
  

   ject 
  was 
  first 
  undertaken 
  from 
  the 
  physical 
  side, 
  when 
  Sir 
  William 
  

   Thomson 
  (Lord 
  Kelvin), 
  in 
  his 
  paper 
  on 
  the 
  secular 
  cooling 
  of 
  

   the 
  earth, 
  announced 
  the 
  conclusion 
  that 
  the 
  age 
  of 
  the 
  earth 
  

   must 
  be 
  more 
  than 
  20 
  millions 
  but 
  less 
  than 
  400 
  millions 
  of 
  years. 
  

   Since 
  that 
  time 
  the 
  physical 
  arguments 
  have 
  been 
  restated 
  and 
  

   reargued 
  by 
  Lord 
  Kelvin 
  and 
  others, 
  the 
  latest 
  conclusion 
  of 
  the 
  

   sanie 
  physicist 
  (Victoria 
  Institute 
  address 
  of 
  1897, 
  see 
  this 
  Jour- 
  

   nal, 
  vii, 
  160), 
  being 
  that 
  the 
  age 
  " 
  was 
  more 
  than 
  twenty 
  and 
  

   less 
  than 
  forty 
  millions 
  of 
  years 
  and 
  probably 
  much 
  nearer 
  twenty 
  

   than 
  forty." 
  

  

  This 
  conclusion, 
  however, 
  has 
  not 
  been 
  universally 
  accepted 
  by 
  

   physicists, 
  for 
  example. 
  Professor 
  Perry 
  in 
  1895 
  closed 
  a 
  discus- 
  

   sion 
  intended 
  to 
  show 
  the 
  uncertainty 
  of 
  the 
  physical 
  data 
  upon 
  

   which 
  the 
  estimate 
  was 
  based, 
  by 
  the 
  remark: 
  "It 
  is 
  to 
  be 
  

   observed 
  that 
  if 
  we 
  exclude 
  everything 
  but 
  the 
  arguments 
  from 
  

   mere 
  physics 
  the 
  ^wohahle 
  age 
  of 
  the 
  earth 
  is 
  much 
  less 
  than 
  any 
  

   of 
  the 
  above 
  estimates 
  ; 
  but 
  if 
  paleontologists 
  have 
  good 
  reasons 
  

   for 
  demanding 
  jnuch 
  greater 
  times, 
  I 
  see 
  nothing 
  from 
  the 
  physi- 
  

   cist's 
  point 
  of 
  view 
  which 
  denies 
  them 
  four 
  times 
  the 
  greatest 
  of 
  

   the 
  estimates." 
  

  

  After 
  this 
  historical 
  summary, 
  the 
  writer 
  goes 
  on 
  to 
  protest 
  

   vigorously 
  against 
  the 
  ignoring 
  of 
  the 
  evidence 
  adduced 
  by 
  geo- 
  

   logist 
  and 
  paleontologist 
  which 
  has 
  often 
  characterized 
  the 
  dis- 
  

   cussions 
  of 
  the 
  physicist. 
  He 
  writes: 
  "It 
  is 
  difficult 
  satisfactorily 
  

   to 
  carry 
  on 
  a 
  discussion 
  in 
  which 
  your 
  opponent 
  entirely 
  ignores 
  

   your 
  arguments, 
  while 
  you 
  have 
  given 
  the 
  fullest 
  attention 
  to 
  his. 
  

  

  