﻿APPENDIX 
  0. 
  367 
  

  

  In 
  considering 
  the 
  changes 
  in 
  the 
  heights 
  of 
  the 
  stations 
  it 
  must 
  be 
  remembered 
  

   that 
  the 
  same 
  dependence 
  cannot 
  be 
  placed 
  upon 
  them 
  as 
  on 
  the 
  positions, 
  refrac- 
  

   tion 
  being 
  much 
  more 
  liable 
  to 
  introduce 
  errors 
  into 
  vertical 
  angles 
  than 
  in 
  hori- 
  

   zontal 
  angles. 
  The 
  changes, 
  it 
  will 
  be 
  observed, 
  are, 
  as 
  a 
  rule, 
  small, 
  but 
  so 
  far 
  

   as 
  they 
  go 
  seem 
  to 
  indicate 
  a 
  slight 
  general 
  upheaval 
  of 
  the 
  hills, 
  Even 
  this 
  

   must, 
  however, 
  be 
  regarded 
  as 
  doubtful. 
  The 
  starting 
  point 
  was 
  Rangsanobo, 
  

   which 
  was 
  assumed 
  unchanged, 
  and 
  calculating 
  from 
  it, 
  Taramun 
  Tila 
  was 
  found 
  

   to 
  have 
  risen 
  6 
  feet. 
  As 
  has 
  been 
  explained 
  the 
  inherent 
  probability 
  is 
  more 
  in 
  

   favour 
  of 
  this 
  station 
  having 
  remained 
  unaltered 
  in 
  height 
  than 
  Rangsanobo, 
  and 
  

   if 
  this 
  was 
  so, 
  then, 
  assuming 
  the 
  results 
  can 
  be 
  depended 
  on, 
  the 
  tabulated 
  

   heights 
  of 
  all 
  other 
  stations 
  would 
  have 
  to 
  be 
  reduced 
  by 
  6 
  feet 
  and 
  as 
  a 
  result 
  the 
  

   height 
  of 
  the 
  Khasi 
  hills 
  would 
  remain 
  practically 
  unchanged, 
  or 
  even 
  diminished. 
  1 
  

   As 
  already 
  mentioned 
  no 
  great 
  weight 
  can 
  be 
  attached 
  to 
  these 
  observations, 
  

   but 
  it 
  is 
  evident 
  that 
  over 
  the 
  area 
  covered 
  by 
  the 
  triangulation 
  there 
  has 
  been 
  no 
  

   marked 
  alterations 
  in 
  the 
  general 
  height 
  of 
  the 
  hills. 
  

  

  There 
  are 
  two 
  stations, 
  however, 
  which 
  form 
  marked 
  exceptions 
  to 
  this 
  general 
  

   rule; 
  Mautherrichan, 
  with 
  a 
  rise 
  of 
  24 
  feet, 
  and 
  Landau 
  Modo 
  with 
  a 
  rise 
  of 
  17 
  

   feet. 
  These 
  amounts 
  may 
  be 
  regarded 
  as 
  in 
  excess 
  of 
  the 
  possible 
  errors 
  of 
  ob- 
  

   servation, 
  and 
  it 
  may 
  be 
  taken 
  that 
  these 
  peaks 
  have 
  risen 
  by 
  noteworthy 
  amounts, 
  

   even 
  though 
  the 
  tabulated 
  values 
  may 
  not 
  be 
  exact 
  to 
  a 
  few 
  feet. 
  

  

  If 
  we 
  look 
  to 
  the 
  situation 
  of 
  these 
  two 
  peaks 
  the 
  explanation 
  of 
  the 
  exceptional 
  

   local 
  elevation 
  becomes 
  clear. 
  Both 
  of 
  them 
  are 
  situated 
  on 
  the 
  crest 
  of 
  conspicuous 
  

   fault 
  scarps, 
  of 
  the 
  type 
  described 
  in 
  Chapter 
  IX, 
  and 
  Landau 
  Modo 
  is 
  close 
  to 
  two 
  

   of 
  the 
  pools 
  formed 
  by 
  distortion 
  of 
  the 
  surface, 
  details 
  of 
  which 
  will 
  be 
  found 
  in 
  

   the 
  same 
  chapter. 
  2 
  

  

  If 
  we 
  turn 
  to 
  the 
  changes 
  in 
  the 
  heights 
  of 
  the 
  secondary 
  stations 
  we 
  find 
  the 
  

   same 
  thing 
  repeated. 
  The 
  only 
  two 
  that 
  seem 
  to 
  have 
  undergone 
  any 
  conspicuous 
  

   change 
  in 
  height 
  are 
  the 
  Mairang 
  and 
  Kollong 
  rock 
  stations, 
  both 
  situated 
  near 
  the 
  

   edge 
  of 
  fault 
  scarps. 
  With 
  the 
  exact 
  position 
  of 
  Laitbli, 
  which 
  has 
  risen 
  9 
  ft., 
  

   I 
  arri 
  unacquainted, 
  but 
  from 
  its 
  position 
  it 
  also 
  is 
  probably 
  on 
  or 
  near 
  the 
  edge 
  of 
  

   one 
  of 
  these 
  fault 
  scarps. 
  

  

  These 
  facts 
  regarding 
  the 
  distribution 
  of 
  changes 
  in 
  the 
  elevation 
  of 
  the 
  hills 
  

   afford 
  a 
  strong 
  confirmation 
  of 
  the 
  description 
  of 
  the 
  structure 
  of 
  the 
  Kh'asi 
  

   and 
  Garo 
  hills 
  given 
  in 
  Chapter 
  IX, 
  and 
  of 
  the 
  explanation 
  given 
  of 
  the 
  nature 
  

   of 
  the 
  focus 
  and 
  the 
  cause 
  of 
  the 
  earthquake 
  given 
  in 
  Chapter 
  X, 
  but 
  were 
  not 
  

   available 
  in 
  time 
  for 
  incorporation 
  in 
  those 
  chapters. 
  

  

  Though 
  the 
  explanation 
  given 
  above 
  of 
  the 
  nature 
  and 
  cause 
  of 
  the 
  displace- 
  

   ments 
  that 
  were 
  observed 
  is 
  that 
  which 
  must 
  be 
  regarded 
  as 
  most 
  probable, 
  it 
  

   must 
  not 
  be 
  forgotten 
  that 
  a 
  different 
  explanation 
  is 
  conceivable. 
  The 
  known 
  facts 
  

   of 
  structural 
  geology 
  show 
  that 
  certain 
  regions 
  have 
  been 
  subject 
  to 
  direct 
  eleva- 
  

   tion 
  which, 
  so 
  far 
  as 
  the 
  surface 
  rocks 
  are 
  concerned, 
  is 
  not 
  due 
  to 
  the 
  indirect 
  

   effects 
  of 
  compression. 
  Besides 
  mountains 
  of 
  compression, 
  of 
  which 
  the 
  Alps 
  and 
  

  

  1 
  The 
  effect 
  of 
  errors 
  in 
  the 
  calculated 
  length 
  of 
  the 
  sides, 
  due 
  to 
  an 
  error 
  in 
  the 
  assumed 
  

   length 
  of 
  the 
  initial 
  base, 
  may 
  be 
  neglected. 
  

   s 
  See 
  p. 
  156. 
  

  

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  367 
  ) 
  

  

  