﻿240 
  

  

  OLDHAM 
  : 
  GREAT 
  EARTHQUAKE 
  OF 
  1897. 
  

  

  

  1 
  

  

  1 
  ■ 
  

  

  3 
  

  

  4 
  

  

  4 
  

  

  1 
  ^ 
  

  

  6 
  

  

  

  First 
  

  

  PHASE. 
  

  

  Second 
  phase. 
  

  

  Large 
  undula- 
  

   tions. 
  

  

  End 
  of 
  

  

  

  Comm. 
  

  

  Max. 
  

  

  Comm. 
  

  

  Max. 
  

  

  Comm. 
  

  

  Max. 
  

  

  distur- 
  

   bance. 
  

  

  

  m. 
  s. 
  

  

  m. 
  s. 
  

  

  m. 
  s. 
  

  

  m 
  s. 
  

  

  m. 
  s. 
  

  

  m. 
  s. 
  

  

  

  Ischia 
  

  

  17 
  13 
  

  

  19 
  19 
  

  

  26 
  

  

  27 
  40 
  

  

  42 
  33 
  

  

  47 
  ° 
  

  

  13". 
  

  

  Rome, 
  Rocca 
  di 
  

   Papa. 
  

  

  „ 
  Ufficio 
  

  

  centrale. 
  

   Fadua 
  • 
  . 
  

  

  17 
  40 
  

  

  ... 
  

  

  25 
  50 
  

  

  ... 
  

  

  4» 
  45 
  

  

  46 
  50 
  

  

  I3h. 
  

  

  17 
  5 
  

   16 
  47 
  

  

  20 
  20 
  

   22 
  

  

  25 
  20 
  

  

  25 
  45 
  

  

  28 
  

   28 
  15 
  

  

  43 
  8 
  

   42 
  30 
  

  

  47 
  

   47 
  10 
  

  

  i 
  S 
  h. 
  

  

  Catania 
  . 
  

  

  17 
  23 
  

  

  ... 
  

  

  25 
  55 
  

  

  26 
  25 
  

  

  45 
  

  

  48 
  

  

  I4h. 
  

  

  Siena 
  • 
  

  

  17 
  

  

  19 
  30 
  

  

  26 
  

  

  27 
  

  

  46 
  

  

  48 
  

  

  ... 
  

  

  Pa 
  via 
  • 
  

  

  18 
  17 
  

  

  20 
  

  

  ... 
  

  

  27 
  

  

  45 
  43 
  

  

  48 
  

  

  i2h. 
  

  

  Grenoble 
  . 
  

  

  19 
  5 
  

  

  ... 
  

  

  ... 
  

  

  ... 
  

  

  ... 
  

  

  ... 
  

  

  ... 
  

  

  Potsdam 
  . 
  

  

  18 
  45 
  

  

  ... 
  

  

  ... 
  

  

  ... 
  

  

  ... 
  

  

  ... 
  

  

  ... 
  

  

  Strassburg 
  

  

  18 
  32 
  

  

  ... 
  

  

  ... 
  

  

  ... 
  

  

  ... 
  

  

  ... 
  

  

  I4*5h. 
  

  

  Edinburgh 
  J 
  

  

  18 
  

  

  ... 
  

  

  28 
  

  

  ... 
  

  

  ... 
  

  

  ... 
  

  

  I4\5h. 
  

  

  In 
  connection 
  with 
  this 
  table 
  and 
  the 
  apparent 
  imperfection 
  of 
  

   the 
  records 
  at 
  all 
  but 
  the 
  Italian 
  observatories, 
  the 
  difference 
  in 
  type 
  

   of 
  the 
  instruments 
  used 
  must 
  be 
  borne 
  in 
  mind. 
  In 
  Italy, 
  heavily 
  

   weighted 
  pendula 
  are 
  favoured, 
  whether 
  vertical 
  or 
  horizontal, 
  and 
  the 
  

   record 
  is 
  made 
  by 
  a 
  pen, 
  or 
  a 
  pointer 
  travelling 
  over 
  a 
  moving 
  strip 
  

   of 
  smoked 
  paper. 
  This 
  type 
  of 
  instrument 
  has 
  some 
  disadvantages, 
  

   but 
  it 
  enables 
  the 
  recording 
  surface 
  to 
  move 
  sufficiently 
  rapidly 
  to 
  

   give 
  an 
  open 
  and 
  detailed 
  record 
  of 
  the 
  displacements 
  of 
  the 
  

   pendulum, 
  and 
  the 
  heavy 
  weight 
  on 
  the 
  pendulum 
  enables 
  it, 
  in 
  

   virtue 
  of 
  its 
  inertia, 
  to 
  record 
  horizontal 
  displacements 
  of 
  the 
  

   instrument 
  which 
  are 
  unaccompanied 
  by 
  tilting. 
  

  

  At 
  Potsdam, 
  Strassburg, 
  and 
  apparently 
  Grenoble, 
  weighted 
  

  

  horizontal 
  pendula 
  were 
  in 
  use. 
  At 
  Potsdam, 
  the 
  instrument 
  was 
  

  

  thrown 
  out 
  of 
  working 
  order 
  shortly 
  after 
  the 
  commencement 
  of 
  the 
  

  

  shock. 
  At 
  Strassburg, 
  the 
  displacement 
  of 
  the 
  pendulum 
  was 
  so 
  

  

  ( 
  240 
  ) 
  

  

  