﻿MOTION 
  OF 
  WAVE 
  PARTICLE. 
  

  

  83 
  

  

  over 
  which 
  the 
  base 
  of 
  the 
  tomb 
  has 
  slid. 
  The 
  pair 
  of 
  tombs 
  and 
  

   the 
  depressions 
  are 
  shown 
  in 
  section 
  in 
  fig. 
  7. 
  

  

  W 
  

  

  iffl 
  

  

  1 
  IT 
  

  

  I 
  TTT 
  

  

  crzn 
  

  

  SH^SEE 
  

  

  Ti 
  

  

  UTTT 
  

  

  18" 
  

  

  

  E 
  

  

  10 
  

  

  Fig. 
  7. 
  Section 
  of 
  tombs 
  in 
  the 
  cemetery 
  at 
  Cherrapunji, 
  

  

  The 
  edge 
  of 
  the 
  western 
  depression 
  has 
  the 
  grass 
  growing 
  undis- 
  

   turbed 
  up 
  to 
  the 
  edge 
  of 
  it, 
  and 
  along 
  the 
  edge 
  small 
  fragments 
  of 
  lime 
  

   and 
  plaster 
  show 
  that 
  this 
  was 
  originally 
  in 
  contact 
  with 
  the 
  edge 
  of 
  

   the 
  tomb, 
  which 
  has 
  now 
  moved 
  away 
  to 
  a 
  distance 
  of 
  18 
  inches. 
  On 
  

   the 
  east 
  the 
  edge 
  of 
  the 
  depression 
  is 
  raised 
  and 
  the 
  grass 
  and 
  earth 
  

   forced 
  upwards 
  by 
  the 
  thrust 
  of 
  the 
  tomb 
  against 
  it; 
  the 
  breadth 
  ot 
  

   this 
  depression 
  is 
  10 
  inches. 
  

  

  These 
  depressions 
  are 
  evidently 
  due 
  to 
  the 
  backward 
  and 
  forward 
  

   movement 
  of 
  the 
  tombs 
  in 
  the 
  ground, 
  or 
  rather 
  the 
  backward 
  and 
  

   forward 
  movement 
  of 
  the 
  ground 
  against 
  the 
  tombs, 
  which 
  remained 
  

   comparatively 
  stationary 
  in 
  consequence 
  of 
  their 
  inertia. 
  If 
  we 
  

   assume 
  that 
  the 
  two 
  tombs 
  behaved 
  as 
  a 
  single 
  mass, 
  but 
  that 
  after 
  the 
  

   shock 
  they 
  were 
  left 
  in 
  a 
  position 
  slightly 
  different 
  from 
  their 
  original 
  

   one, 
  the 
  range 
  of 
  motion 
  of 
  the 
  earth 
  would 
  be 
  the 
  mean 
  of 
  the 
  

   widths 
  of 
  the 
  two 
  depressions, 
  that 
  is 
  14 
  inches. 
  But 
  the 
  earth 
  on 
  the 
  

   east 
  has 
  obviously 
  been 
  forced 
  up, 
  while 
  that 
  on 
  the 
  west 
  has 
  not 
  ; 
  the 
  

   movement 
  on 
  the 
  east 
  side 
  has 
  consequently 
  received 
  a 
  check 
  which 
  

   that 
  on 
  the 
  other 
  has 
  not, 
  and 
  we 
  may 
  take 
  the 
  wider 
  depression, 
  18 
  

   inches, 
  as 
  representing 
  the 
  range 
  of 
  movement. 
  A 
  third 
  supposition 
  

   is 
  that 
  the 
  two 
  tombs 
  have 
  not 
  exactly 
  retained 
  their 
  original 
  relative 
  

   position, 
  but 
  have 
  been 
  pressed 
  closer 
  together 
  : 
  if 
  this 
  was 
  due 
  to 
  an 
  

   easterly 
  movement 
  of 
  the 
  western 
  tomb, 
  then 
  18 
  inches 
  would 
  repre- 
  

   sent 
  the 
  range 
  of 
  movement 
  added 
  to 
  the 
  displacement 
  of 
  the 
  

  

  (83) 
  

  

  c 
  2 
  

  

  