﻿198 
  OLDHAM: 
  GREAT 
  EARTHQUAKE 
  OF 
  1897. 
  

  

  longed 
  rumble, 
  died 
  slowly 
  off. 
  Occasionally 
  the 
  sound 
  com- 
  

   menced 
  abruptly 
  and 
  ended 
  soon, 
  resembling 
  the 
  sound 
  of 
  a 
  small 
  

   cannon, 
  or 
  in 
  some 
  cases 
  of 
  a 
  shot-gun 
  loaded 
  with 
  black 
  powder 
  

   and 
  fired 
  at 
  a 
  distance 
  of 
  quarter 
  of 
  a 
  mile. 
  

  

  I 
  tried 
  to 
  discover 
  if 
  any 
  variation 
  in 
  the 
  pitch 
  of 
  the 
  note 
  was 
  

   observable, 
  and 
  though 
  it 
  did 
  seem 
  in 
  a 
  few 
  cases 
  that 
  the 
  pitch, 
  

   as 
  opposed 
  to 
  the 
  volume, 
  was 
  highest 
  at 
  the 
  commencement 
  and 
  

   sank 
  as 
  the 
  sound 
  increased 
  in 
  volume, 
  yet 
  no 
  general 
  rule 
  of 
  

   this 
  sort 
  could 
  be 
  noticed 
  ; 
  variations 
  in 
  pitch 
  were 
  seldom 
  notice- 
  

   able, 
  and 
  when 
  they 
  were, 
  occurred 
  without 
  any 
  regularity 
  of 
  

   order. 
  The 
  sounds 
  are 
  in 
  fact 
  so 
  close 
  to 
  the 
  lower 
  limit 
  of 
  audibility 
  

   that 
  there 
  is 
  little 
  room 
  for 
  variation 
  of 
  pitch. 
  They 
  are 
  indeed 
  

   less 
  a 
  note 
  than 
  a 
  rumble, 
  and 
  resemble 
  nothing 
  more 
  than 
  distant 
  

   thunder. 
  Of 
  this 
  1 
  had 
  a 
  good 
  proof, 
  for 
  on 
  the 
  morning 
  of 
  the 
  26th 
  

   January 
  when 
  marching 
  from 
  Samin 
  to 
  Cheran, 
  a 
  thunderstorm 
  came 
  

   up 
  from 
  the 
  south-west, 
  and 
  I 
  found 
  it 
  impossible 
  to 
  distinguish 
  

   between 
  the 
  earthquake 
  sounds 
  and 
  the 
  thunder 
  at 
  a 
  distance 
  of 
  one 
  

   to 
  three 
  miles. 
  

  

  Very 
  frequently 
  the 
  sound 
  had 
  not 
  the 
  continuous 
  nature 
  of 
  

   thunder 
  and 
  was 
  rather 
  a 
  very 
  rapid 
  succession 
  of 
  short 
  sounds, 
  a 
  

   rattle 
  or 
  rumble 
  in 
  fact, 
  not 
  unlike 
  the 
  sound 
  made 
  by 
  a 
  cart 
  driven 
  

   rapidly 
  over 
  a 
  rough 
  pavement. 
  

  

  An 
  interesting 
  point 
  to 
  determine 
  is 
  whether 
  the 
  sounds 
  travel 
  

   through 
  the 
  air, 
  or 
  originate 
  locally. 
  If 
  they 
  travelled 
  any 
  distance 
  

   through 
  the 
  air 
  it 
  is 
  obvious 
  that 
  the 
  apparent 
  duration 
  of 
  the 
  sound 
  

   would 
  not 
  correspond 
  with 
  the 
  real 
  duration 
  of 
  the 
  earth 
  vibrations 
  

   by 
  which 
  it 
  was 
  caused. 
  The 
  rate 
  of 
  travel 
  of 
  sound 
  through 
  the 
  

   air 
  is 
  much 
  slower 
  than 
  through 
  rock 
  and, 
  after 
  the 
  sound 
  vibrations 
  

   communicated 
  to 
  the 
  air 
  in 
  the 
  immediate 
  vicinity 
  of 
  the 
  observer 
  

   had 
  ceased, 
  he 
  would 
  still 
  hear 
  the 
  sound 
  due 
  to 
  the 
  vibrations 
  

   which 
  were 
  communicated 
  to 
  the 
  air 
  at 
  a 
  distance 
  and 
  gradually 
  

   reached 
  him 
  by 
  the 
  slower 
  route 
  of 
  travel. 
  

   ( 
  198 
  ) 
  

  

  