﻿HATDEN.J 
  LETTER 
  TO 
  THE 
  SECRETARY. 
  5 
  

  

  The 
  work 
  was 
  generally 
  done 
  by 
  means 
  of 
  the 
  plane-table, 
  and 
  reen- 
  

   forced 
  by 
  both 
  vertical 
  and 
  drainage 
  sketches 
  from 
  all 
  the 
  stations, 
  and 
  

   also 
  by 
  time-meanders 
  of 
  all 
  the 
  main 
  streams, 
  and 
  generally 
  by 
  a 
  run- 
  

   ning 
  sketch 
  of 
  the 
  routes 
  traveled. 
  The 
  main 
  stations 
  averaged 
  one 
  to 
  

   every 
  seventy-Jive 
  square 
  miles 
  of 
  area. 
  

  

  By 
  meandering, 
  Mr. 
  Chittenden 
  surveyed 
  the 
  San 
  Juan 
  River, 
  the 
  La 
  

   Plata, 
  the 
  Mancos, 
  and 
  the 
  Dolores, 
  all 
  of 
  them 
  considerable 
  streams, 
  

   and 
  besides 
  these 
  the 
  McElmo 
  and 
  Montezuma 
  Creeks, 
  which, 
  though 
  

   well 
  defined 
  stream-beds, 
  contain 
  no 
  running 
  water. 
  These 
  last-named 
  

   dry 
  rivers 
  are 
  each 
  upward 
  of 
  seventy-five 
  miles 
  long, 
  and 
  for 
  a 
  consid- 
  

   erable 
  part 
  of 
  their 
  course 
  are 
  in 
  deep 
  caQons. 
  In 
  the 
  meander, 
  he 
  made 
  

   a 
  trigonometric 
  location 
  as 
  often 
  as 
  once 
  in 
  ten 
  miles. 
  

  

  The 
  great 
  trouble 
  in 
  working 
  was 
  lack 
  of 
  water. 
  The 
  party 
  were 
  

   often 
  obliged 
  to 
  ride 
  out 
  ten, 
  fifteen, 
  and 
  even 
  twenty 
  miles 
  from 
  the 
  

   rivers 
  to 
  make 
  a 
  station 
  and 
  back 
  again 
  for 
  camp, 
  because 
  outside 
  of 
  

   the 
  rivers 
  themselves 
  there 
  was 
  no 
  water 
  at 
  all. 
  

  

  In 
  regard 
  to 
  the 
  systems 
  of 
  working 
  generally 
  employed 
  now 
  in 
  the 
  

   different 
  surveys 
  west 
  of 
  the 
  Missouri 
  Eiver, 
  the 
  plane-table 
  system, 
  

   which 
  was 
  generally 
  used 
  this 
  summer, 
  is 
  admirably 
  adapted 
  to 
  a 
  low, 
  

   broken 
  country, 
  where 
  good 
  "points" 
  are 
  abundant, 
  and 
  works 
  also 
  ex- 
  

   tremely 
  well 
  in 
  a 
  simple 
  canon 
  country, 
  where 
  there 
  are 
  surrounding 
  

   prominent 
  points 
  at 
  not 
  too 
  great 
  distance. 
  But 
  in 
  a 
  mountain 
  country, 
  

   it 
  could 
  not 
  be 
  used 
  to 
  any 
  advantage, 
  and 
  was 
  eventually 
  abandoned 
  

   in 
  all 
  the 
  mountain 
  work. 
  In 
  low, 
  broken, 
  and 
  canon 
  country, 
  it 
  is 
  prob- 
  

   ably 
  the 
  best 
  system 
  that 
  can 
  be 
  used 
  ; 
  but, 
  in 
  the 
  ordinary 
  rolling 
  and 
  

   mountainous 
  country 
  of 
  the 
  Northwest, 
  it 
  will 
  not 
  repay 
  the 
  extra 
  weight 
  

   and 
  time 
  which 
  its 
  use 
  entails. 
  

  

  In 
  any 
  but 
  a 
  very 
  mountainous 
  country, 
  a 
  system 
  of 
  meander 
  seems 
  

   to 
  be 
  almost 
  necessary 
  to 
  make 
  work 
  on 
  a 
  scale 
  of 
  four 
  inches 
  to 
  a 
  mile 
  

   complete. 
  It 
  is 
  the 
  abuse, 
  and 
  not 
  the 
  use, 
  of 
  the 
  old 
  odometer 
  system 
  

   that 
  has 
  brought 
  it 
  into 
  so 
  much 
  discredit. 
  If 
  properly 
  checked, 
  the 
  

   meanders 
  give 
  to 
  the 
  more 
  important 
  portions 
  of 
  the 
  country, 
  as 
  the 
  trav- 
  

   eled 
  routes 
  and 
  principal 
  rivers, 
  the 
  greater 
  degree 
  of 
  accuracy 
  which 
  

   is 
  their 
  due. 
  The 
  third 
  and 
  only 
  remaining 
  system 
  in 
  use 
  in 
  the 
  West 
  

   is 
  that 
  generally 
  employed 
  on 
  this 
  Survey, 
  and 
  formerly 
  used 
  both 
  in 
  the 
  

   California 
  Survey 
  and 
  in 
  thatof 
  the 
  fortieth 
  parallel. 
  Itconsists 
  of 
  a 
  sys- 
  

   tem 
  of 
  vertical 
  and 
  horizontal 
  sketches 
  based 
  on 
  a 
  rather 
  elaborate 
  tri- 
  

   angulation, 
  and 
  checked 
  by 
  numerous 
  angles, 
  both 
  vertical 
  and 
  hori- 
  

   zontal. 
  This 
  system 
  is 
  peculiarly 
  adapted 
  to 
  arolliugor 
  mountainous 
  coun- 
  

   try, 
  and 
  in 
  such 
  country 
  cannot 
  be 
  equale<l 
  by 
  either 
  of 
  the 
  other 
  modes. 
  

   It 
  works 
  well, 
  too, 
  in 
  country 
  of 
  different 
  character, 
  and 
  is 
  probably, 
  on 
  

   the 
  whole, 
  the 
  best 
  system 
  on 
  which 
  to 
  base 
  work 
  in 
  the 
  average 
  coun- 
  

   try 
  of 
  the 
  West. 
  It 
  should, 
  however, 
  be 
  supplemented 
  by 
  good 
  mean- 
  

   ders 
  of 
  all 
  the 
  main 
  roads 
  and 
  rivers. 
  In 
  the 
  work 
  of 
  the 
  Survey 
  this 
  

   summer, 
  the 
  three 
  systems 
  were 
  employed, 
  and 
  the 
  above 
  remarks 
  are 
  

   the 
  immediate 
  result 
  of 
  the 
  summer's 
  observations. 
  

  

  