﻿nAYUE>7.] 
  LETTEE 
  TO 
  THE 
  SECRETARY. 
  21 
  

  

  may 
  be. 
  This 
  is 
  a 
  perfectly 
  natural 
  condition 
  of 
  things; 
  for 
  where 
  the 
  

   geological 
  series 
  is 
  complete, 
  no 
  man 
  can 
  say 
  where 
  one 
  formation 
  ends 
  

   and 
  another 
  begins. 
  

  

  In 
  1870, 
  a 
  photograt)her 
  was 
  attached 
  to 
  the 
  Survey, 
  and 
  the 
  results 
  

   arising 
  therefrom 
  have 
  fully 
  proven 
  the 
  wisdom 
  of 
  thus 
  adding 
  a 
  most 
  

   useful 
  art 
  to 
  the 
  organization. 
  An 
  unthinking 
  public 
  might 
  imagine 
  

   that 
  the 
  employment 
  of 
  photography 
  in 
  connection 
  with 
  the 
  work 
  of 
  

   the 
  Survey 
  is 
  more 
  ornamental 
  than 
  useful, 
  and 
  that 
  the 
  sole 
  business 
  

   of 
  the 
  photographer 
  is 
  to 
  secure 
  in 
  the 
  field 
  a 
  number 
  of 
  pictures 
  merely 
  

   to 
  please 
  the 
  eye, 
  and 
  not 
  for 
  practical 
  and 
  scientific 
  use. 
  This 
  idea 
  

   is 
  so 
  at 
  variance 
  with 
  those 
  believed 
  to 
  be 
  popularly 
  entertained 
  as 
  to 
  

   practical 
  economy, 
  that 
  it 
  seems 
  worth 
  while 
  to 
  enumerate 
  some 
  of 
  the 
  

   many 
  useful 
  applications 
  photography 
  may 
  be 
  put 
  to. 
  Although 
  in 
  its 
  

   infancy, 
  it 
  has 
  been 
  so 
  successfully 
  applied 
  to 
  many 
  branches 
  of 
  Gov- 
  

   ernment 
  work 
  that 
  it 
  is 
  now 
  considered 
  a 
  necessity 
  of 
  any 
  well 
  organ- 
  

   ized 
  expedition, 
  or 
  in 
  any 
  office 
  where 
  there 
  is 
  any 
  considerable 
  amount 
  

   of 
  illustrating 
  or 
  designing, 
  notably 
  so 
  with 
  the 
  English 
  and 
  continental 
  

   governments, 
  where 
  large 
  schools 
  of 
  instruction 
  are 
  supported 
  for 
  the 
  

   sole 
  purpose 
  of 
  turning 
  out 
  skilled 
  employes. 
  

  

  In 
  our 
  own 
  country, 
  photography 
  was 
  first 
  used 
  to 
  any 
  extent 
  by 
  the 
  

   Government 
  during 
  the 
  war 
  in 
  securing 
  series 
  of 
  illustrations 
  for 
  the 
  Sur- 
  

   geon-General 
  and 
  Engineer 
  bureaus, 
  and 
  since 
  then 
  for 
  the 
  reproduction 
  

   of 
  the 
  drawings 
  of 
  the 
  Supervising 
  Architect, 
  and 
  other 
  work 
  of 
  like 
  na- 
  

   ture 
  for 
  the 
  United 
  States 
  Treasurer's 
  office. 
  This 
  establishment 
  is 
  the 
  

   nearest 
  approach 
  to 
  those 
  maintained 
  at 
  Woolwich, 
  Berlin, 
  Paris, 
  and 
  

   Vienna, 
  but 
  is 
  insignificant 
  in 
  comi:)arison 
  with 
  them. 
  

  

  After 
  the 
  close 
  of 
  the 
  war, 
  the 
  previous 
  good 
  services 
  of 
  photog- 
  

   raphy 
  in 
  the 
  field 
  recommended 
  it 
  to 
  the 
  exploring 
  and 
  surveying 
  ex- 
  

   peditions, 
  and 
  it 
  was 
  extensively 
  employed 
  by 
  them. 
  A 
  photographic 
  

   corps 
  was 
  attached 
  to 
  the 
  Survey 
  in 
  1870, 
  and 
  it 
  has 
  continued 
  its 
  use 
  

   ever 
  since. 
  Besides 
  the 
  constant 
  and 
  important 
  use 
  made 
  of 
  these 
  

   illustrations 
  in 
  the 
  preparation 
  of 
  the 
  geological 
  and 
  toj)ographical 
  

   reports, 
  copies 
  of 
  them 
  are 
  now 
  used 
  by 
  professors 
  in 
  all 
  the 
  principal 
  

   colleges 
  of 
  the 
  land 
  to 
  illustrate 
  their 
  geological 
  teachings. 
  

  

  The 
  photographic 
  work 
  has 
  been 
  under 
  the 
  direction 
  of 
  Mr. 
  W. 
  H. 
  

   Jackson, 
  an 
  experienced 
  landscape-photographer, 
  who 
  has 
  made 
  an 
  

   average 
  of 
  400 
  negatives 
  each 
  year, 
  ranging 
  in 
  size 
  from 
  the 
  stereo- 
  

   scopic 
  up 
  to 
  plates 
  20 
  by 
  24 
  inches 
  square. 
  The 
  first 
  year 
  the 
  work 
  lay 
  

   entirely 
  within 
  Wyoming 
  and 
  Utah 
  Territories. 
  In 
  1871 
  and 
  1872, 
  the 
  

   expeditions 
  to 
  the 
  Yellowstone 
  regions 
  afforded 
  opportunities 
  that 
  were 
  

   not 
  lost, 
  and 
  the 
  splendid 
  series 
  of 
  photographs 
  then 
  secured 
  have 
  re- 
  

   tained 
  their 
  poi)ularity 
  to 
  this 
  day. 
  In 
  1873, 
  1874, 
  and 
  1875, 
  the 
  work 
  

   was 
  transferred 
  to 
  Colorado, 
  and 
  the 
  operations 
  of 
  the 
  first 
  season 
  were 
  

   confined 
  to 
  the 
  mountain-ranges 
  bordering 
  the 
  Middle 
  and 
  South 
  Parks 
  

   and 
  the 
  Elk 
  Blountains 
  beyond. 
  It 
  was 
  on 
  the 
  trip 
  of 
  1873 
  that 
  Mr. 
  

   Jackson 
  made 
  one 
  of 
  his 
  greatest 
  successes, 
  in 
  securing 
  a 
  fine 
  view 
  of 
  

  

  