﻿110 
  C. 
  Keyes 
  — 
  A 
  Rotating 
  Straticulate 
  Spheroid. 
  

  

  that 
  there 
  is 
  a 
  notable 
  flexing 
  inward, 
  a 
  folding 
  so 
  sharp 
  

   at 
  times 
  that 
  if 
  the 
  paper 
  were 
  not 
  so 
  tough, 
  but 
  brittle 
  

   instead, 
  rupture 
  or, 
  to 
  use 
  the 
  strictly 
  geological 
  term, 
  

   typical 
  faulting 
  would 
  ensue. 
  

  

  Structures 
  thus 
  artificially 
  produced 
  in 
  miniature 
  

   simulate 
  in 
  all 
  essential 
  particulars 
  those 
  familiar 
  flex- 
  

   ures 
  which 
  distinguish 
  the 
  great 
  mountain 
  ranges 
  of 
  the 
  

   globe. 
  Several 
  of 
  the 
  results 
  are 
  reproduced 
  in 
  the 
  

   accompanying 
  cuts 
  which 
  are 
  pen 
  tracings 
  of 
  photo- 
  

   graphs. 
  They 
  are 
  not 
  especially 
  selected 
  as 
  isolated 
  

   examples 
  but 
  are 
  normal 
  recurring 
  figures. 
  Reproduced 
  

   a 
  thousand 
  times 
  they 
  seem 
  to 
  be 
  the 
  necessary 
  conse- 
  

   quence 
  of 
  diminishing 
  tangential 
  stresses. 
  The 
  forma- 
  

   tion 
  of 
  a 
  simple 
  continental 
  geoanticline 
  is 
  most 
  remark- 
  

   able 
  (fig. 
  1). 
  With 
  its 
  elevated 
  margins 
  and 
  its 
  interior 
  

   basin 
  there 
  is 
  exact 
  counterpart 
  of 
  North 
  America 
  

   bordered 
  on 
  either 
  ocean 
  by 
  lofty 
  mountain 
  ranges. 
  

  

  By 
  the 
  use 
  of 
  layered 
  materials 
  not 
  so 
  tough 
  as 
  paper 
  

   the 
  characteristic 
  faulting 
  phenomena 
  could 
  be 
  no 
  doubt 
  

   also 
  developed. 
  Were 
  the 
  straticulate 
  shell 
  of 
  the 
  roll 
  or 
  

   spheroid 
  so 
  constructed 
  as 
  to 
  provide 
  a 
  texture 
  and 
  

   arrangement 
  of 
  the 
  component 
  layers 
  more 
  nearly 
  cor- 
  

   responding 
  to 
  the 
  conditions 
  found 
  in 
  nature, 
  major 
  oro- 
  

   graphic 
  structures 
  would 
  result 
  as 
  perfect 
  as 
  any 
  

   displayed 
  anywhere 
  in 
  the 
  world. 
  This 
  is 
  readily 
  

   accomplished 
  by 
  a 
  little 
  prior 
  calculation 
  of 
  relative 
  

   rigidity 
  and 
  viscosity 
  values 
  of 
  the 
  materials 
  and 
  by 
  the 
  

   exercise 
  in 
  the 
  experiments 
  of 
  a 
  little 
  ingenuity 
  in 
  the 
  

   selection 
  and 
  arrangement 
  of 
  the 
  layered 
  masses. 
  

   Under 
  these 
  circumstances 
  one 
  would 
  expect 
  structural 
  

   replicas 
  of 
  all 
  of 
  the 
  great 
  wrinkles. 
  However, 
  the 
  main 
  

   interest 
  in 
  the 
  experimental 
  results 
  lies 
  in 
  another 
  

   direction. 
  

  

  In 
  the 
  mountain-flexing 
  experiments 
  of 
  Reyer, 
  Cadell, 
  

   Willis, 
  and 
  Poulcke 
  the 
  theme 
  is 
  approached 
  from 
  the 
  

   direction 
  of 
  a 
  contracting 
  crust 
  due 
  to 
  a 
  cooling 
  globe. 
  

   In 
  the 
  later 
  attack 
  on 
  the 
  problem 
  secular 
  refrigeration 
  

   of 
  the 
  earth 
  is 
  not 
  considered. 
  Buckling 
  of 
  this 
  outer 
  

   rock 
  shell 
  is 
  regarded 
  as 
  initiated 
  through 
  the 
  cumula- 
  

   tive 
  effects 
  of 
  the 
  retardation 
  of 
  the 
  earth's 
  rotation, 
  

   rn 
  a 
  revolving 
  sphere 
  the 
  radius 
  of 
  molar 
  equilibrium 
  is 
  

   not 
  a 
  straight 
  line 
  but 
  a 
  curve, 
  which 
  as 
  the 
  rate 
  of 
  revo- 
  

   lution 
  diminishes 
  approaches 
  nearer 
  and 
  nearer 
  a 
  true 
  

   radius 
  and 
  a 
  straighl 
  line. 
  The 
  lagging 
  of 
  the 
  outermost 
  

  

  