﻿158 
  EEPORT 
  UNITED 
  STATES 
  GEOLOGICAL 
  SURVEY. 
  

  

  stages 
  of 
  development. 
  It 
  is 
  a 
  copy 
  of 
  one 
  of 
  the 
  innumerable 
  groups 
  

   studding 
  the 
  tops 
  of 
  the 
  walls. 
  There 
  of 
  course 
  the 
  height 
  of 
  the 
  col- 
  

   umns 
  is 
  not 
  so 
  considerable 
  as 
  of 
  those 
  starting 
  near 
  their 
  bases. 
  From 
  

   the 
  numerous 
  needles 
  and 
  remnants 
  of 
  needles 
  on 
  the 
  walls, 
  it 
  may 
  be 
  

   inferred 
  that 
  there 
  the 
  existence 
  of 
  the 
  monuments 
  is 
  by 
  far 
  shorter 
  

   than 
  below, 
  where 
  they 
  are 
  less 
  exposed 
  to 
  the 
  wind 
  and 
  to 
  the 
  conse- 
  

   quently 
  more 
  severe 
  erosion 
  both 
  by 
  sand 
  and 
  water. 
  It 
  requires 
  but 
  

   little 
  force, 
  directly 
  applied, 
  to 
  overthrow 
  a 
  monument 
  there 
  1 
  or 
  2 
  feet 
  

   in 
  diameter. 
  

  

  Another 
  feature 
  adding 
  to 
  the 
  interest 
  of 
  this 
  locality 
  is 
  found 
  in 
  the 
  

   natural 
  arches 
  formed 
  in 
  the 
  narrow 
  vertical 
  walls. 
  Speaking 
  of 
  the 
  

   walls 
  as 
  narrow, 
  it 
  may 
  be 
  stated 
  that 
  this 
  is 
  meant 
  comparatively. 
  

   They 
  are 
  from 
  30 
  to 
  160 
  feet 
  in 
  width 
  above, 
  but 
  compared 
  with 
  their 
  

   length 
  and 
  height 
  even 
  this 
  produces 
  the 
  impression 
  of 
  very 
  narrow 
  

   width. 
  Altogether 
  we 
  found 
  eleven 
  of 
  these 
  arches, 
  nearly 
  all 
  of 
  which 
  

   were 
  remarkable 
  for 
  their 
  great 
  regularity 
  of 
  outline. 
  The 
  one 
  repre- 
  

   sented 
  by 
  the 
  illustration 
  is 
  perhaps 
  the 
  most 
  regular, 
  and 
  sufficiently 
  

   low 
  down 
  in 
  the 
  wall 
  to 
  be 
  surrounded 
  by 
  monuments. 
  As 
  Mr. 
  F. 
  

   Ehoda 
  of 
  our 
  party 
  was 
  the 
  first 
  one 
  to 
  find 
  an 
  arch, 
  I 
  have 
  named 
  

   this 
  one 
  Rhoda's 
  Arch. 
  It 
  is 
  about 
  150 
  feet 
  wide 
  and 
  180 
  feet 
  high, 
  very 
  

   symmetrical 
  in 
  outline, 
  leaning 
  slightly 
  toward 
  the 
  east 
  however. 
  A 
  

   number 
  of 
  high 
  monuments, 
  the 
  highest 
  reaching 
  over 
  200 
  feet, 
  are 
  in 
  

   the 
  foreground, 
  where 
  the 
  interspersed 
  spruce 
  trees 
  look 
  very 
  diminu- 
  

   tive, 
  compared 
  with 
  the 
  towering 
  forms 
  of 
  the 
  monuments. 
  As 
  regards 
  

   the 
  formation 
  of 
  these 
  arches, 
  an 
  idea 
  suggested 
  itself 
  in 
  consequence 
  

   of 
  studying 
  the 
  conglomerate. 
  It 
  was 
  found 
  that 
  at 
  many 
  places 
  th« 
  

   sand 
  more 
  loosely 
  cemented 
  the 
  bowlders 
  than 
  was 
  generally 
  the 
  case, 
  

   and 
  there 
  niches 
  were 
  worn 
  into 
  the 
  walls 
  by 
  the 
  action 
  of 
  erosion. 
  

   Should 
  the 
  process 
  that 
  produced 
  these 
  niches 
  be 
  continued, 
  the 
  result 
  

   will 
  be 
  a 
  perforation 
  of 
  the 
  wall 
  — 
  the 
  formation 
  of 
  an 
  arch. 
  It 
  is 
  read- 
  

   ily 
  conceivable 
  how 
  the 
  process 
  of 
  erosion 
  would 
  progress 
  more 
  rapidly 
  

   after 
  the 
  first 
  decided 
  start 
  had 
  been 
  made, 
  and 
  the 
  arches 
  in 
  their 
  pres- 
  

   ent 
  form 
  would 
  require 
  much 
  less 
  time 
  to 
  be 
  completed 
  than 
  the 
  niche 
  

   which 
  was 
  their 
  beginning. 
  Many 
  niches 
  were 
  found, 
  but 
  they 
  are, 
  as 
  

   a 
  rule, 
  so 
  absolutely 
  inaccessible, 
  that 
  the 
  investigations 
  as 
  to 
  the 
  na- 
  

   ture 
  of 
  the 
  conglomerate 
  in 
  which 
  they 
  occurred 
  was 
  necessarily 
  limit- 
  

   ed 
  to 
  a 
  few 
  instances 
  only. 
  Although 
  we 
  frequently 
  met 
  with 
  the 
  same 
  

   conglomerate 
  during 
  the 
  summer, 
  we 
  never 
  found 
  another 
  locality 
  where 
  

   these 
  monuments 
  had 
  been 
  formed. 
  Why 
  the 
  valley 
  of 
  South 
  River 
  

   should 
  be 
  thus 
  favored 
  is 
  not 
  very 
  apparent. 
  The 
  eastern 
  ridge, 
  upon 
  

   the 
  west 
  slope 
  of 
  which 
  they 
  are 
  found, 
  is 
  narrow, 
  densely 
  timbered, 
  and 
  

   shows 
  no 
  evidence 
  of 
  having 
  turned 
  large 
  quantities 
  of 
  water 
  in 
  the 
  

   direction 
  of 
  the 
  monuments. 
  From 
  the 
  south 
  water 
  might 
  have 
  

   flowed 
  freely, 
  but 
  the 
  transverse 
  position 
  of 
  the 
  walls 
  excludes 
  the 
  

   probability 
  of 
  water 
  coming 
  from 
  that 
  direction 
  having 
  had 
  any 
  consid- 
  

   erable 
  influence 
  in 
  the 
  eroding 
  of 
  the 
  unique 
  forms. 
  The 
  explanation 
  is 
  

   probably 
  to 
  be 
  sought 
  in 
  the 
  physical 
  constitution 
  of 
  the 
  conglomerate, 
  

   which 
  is 
  so 
  peculiarly 
  adapted 
  to 
  the 
  formation 
  of 
  monuments 
  of 
  that 
  

   character. 
  In 
  time 
  — 
  though 
  it 
  may 
  take 
  ages 
  — 
  the 
  capped 
  columns 
  will 
  

   be 
  transformed 
  into 
  needles, 
  they 
  in 
  turn 
  will 
  disappear, 
  to 
  leave 
  noth- 
  

   ing 
  but 
  a 
  small 
  remnant 
  of 
  debris; 
  all 
  the 
  beauty 
  of 
  that 
  rarely-visited 
  

   spot 
  will 
  then 
  have 
  vanished. 
  

  

  Above 
  station 
  27 
  on 
  the 
  Rio 
  Grande 
  Antelope 
  Park 
  begins. 
  Bor- 
  

   dered 
  on 
  the 
  north 
  by 
  the 
  long 
  bluff 
  that 
  runs 
  parallel 
  to 
  the 
  precipitous 
  

   edge 
  of 
  the 
  plateau 
  upon 
  which 
  Bristol 
  Head 
  is 
  located, 
  the 
  valley 
  

   stretches 
  along 
  in 
  a 
  westerly 
  direction. 
  On 
  the 
  south 
  the 
  steeper 
  slopes 
  

  

  