﻿204 
  Bucher 
  — 
  Origin 
  of 
  Ripples, 
  and 
  

  

  the 
  production 
  of 
  such 
  undulations, 
  the 
  clay 
  must 
  be 
  of 
  

   the 
  right 
  degree 
  of 
  dampness 
  and 
  the 
  snow 
  in 
  the 
  state 
  

   to 
  bind 
  under 
  pressure. 
  

  

  While 
  original 
  irregularities 
  in 
  the 
  road 
  certainly 
  

   tend 
  to 
  produce 
  this 
  effect, 
  the 
  author 
  "has 
  found, 
  by 
  

   experiments 
  with 
  a 
  miniature 
  sledge, 
  that, 
  when 
  the 
  

   detritus 
  of 
  the 
  road 
  consolidates 
  readily 
  under 
  pressure, 
  

   these 
  undulations 
  arise 
  spontaneously 
  by 
  the 
  action 
  of 
  a 
  

   steadily 
  moving 
  sledge 
  when 
  furrowing 
  a 
  homogeneous 
  

   and 
  level 
  road. 
  ' 
  ' 
  In 
  the 
  author 
  's 
  experiments 
  the 
  definite 
  

   wave-length 
  of 
  these 
  undulations 
  was 
  about 
  three 
  and 
  a 
  

   half 
  times 
  the 
  length 
  of 
  the 
  sledge. 
  

  

  The 
  peculiar 
  cross-ridges 
  so 
  numerous 
  on 
  our 
  

   asphalted 
  automobile 
  roads 
  apparently 
  owe 
  their 
  origin 
  

   to 
  the 
  same 
  process. 
  Their 
  intimate 
  connection 
  with 
  

   original 
  irregularities 
  is 
  evident 
  in 
  most 
  cases. 
  

  

  An 
  analogous 
  process 
  was 
  observed 
  by 
  A. 
  M. 
  Miller 
  77 
  

   on 
  the 
  Canadian 
  Pacific 
  R. 
  R., 
  west 
  of 
  Sudbury, 
  Ontario. 
  

   A 
  freight 
  train, 
  moving 
  over 
  a 
  track 
  built 
  across 
  

   "muskeg" 
  on 
  a 
  fill 
  with 
  ordinary 
  ties, 
  threw 
  the 
  track 
  

   into 
  very 
  pronounced 
  undulations, 
  which 
  caused 
  the 
  mud 
  

   and 
  water 
  to 
  be 
  squashed 
  out 
  at 
  regular 
  intervals 
  

   (roughly 
  estimated 
  at 
  20 
  feet). 
  

  

  The 
  transverse 
  ridges 
  sculpturing 
  icicles 
  and 
  stalac- 
  

   tites 
  perhaps 
  represent 
  another 
  expression 
  of 
  the 
  same 
  

   tendency 
  to 
  form 
  the 
  sinuous 
  surface 
  of 
  least 
  friction. 
  

  

  The 
  peculiar 
  ruffling 
  of 
  rock 
  surfaces 
  polished 
  by 
  the 
  

   sand-blast 
  action 
  of 
  desert 
  storms, 
  described 
  by 
  Hobbs 
  

   as 
  "strikingly 
  similar 
  to 
  the 
  ruffled 
  surface 
  of 
  "a 
  billow 
  

   or 
  water, 
  ' 
  ' 
  78 
  may 
  owe 
  its 
  origin 
  to 
  the 
  same 
  cause. 
  The 
  

   enlargement 
  of 
  slight 
  original 
  irregularities 
  of 
  the 
  sur- 
  

   face 
  may 
  well 
  have 
  proceeded 
  in 
  such 
  directions 
  which 
  

   tended 
  to 
  establish 
  a 
  surface 
  of 
  least 
  resistance 
  rather 
  

   than 
  any 
  other. 
  

  

  A 
  hand 
  specimen 
  of 
  nearly 
  white 
  St. 
  Louis 
  limestone, 
  

   collected 
  by 
  N. 
  M. 
  Fenneman 
  from 
  the 
  bottom 
  of 
  one 
  of 
  

   the 
  subterranean 
  streams 
  in 
  White's 
  cave 
  near 
  Burks- 
  

   ville, 
  Mo., 
  79 
  suggests 
  an 
  analogous 
  process 
  at 
  the 
  contact 
  

   of 
  limestone 
  and 
  water 
  (see 
  fig. 
  10). 
  The 
  surface 
  is 
  

   covered 
  with 
  more 
  or 
  less 
  irregular 
  rhomboidal 
  pits 
  

  

  77 
  Oral 
  communication. 
  

  

  78 
  Hobbs, 
  W. 
  H., 
  Range 
  and 
  Rhythmic 
  action 
  of 
  sand-blast 
  erosion, 
  Bull. 
  

   Geol. 
  Soc. 
  Am., 
  vol. 
  26, 
  p. 
  63, 
  1915. 
  

  

  79 
  Now 
  in 
  the 
  collection 
  of 
  the 
  geological 
  department 
  of 
  the 
  University 
  of 
  

   Cincinnati. 
  

  

  