﻿THE 
  ONFELT 
  EARTHQUAKE. 
  237 
  

  

  The 
  disturbance 
  commenced 
  at 
  nh. 
  18m. 
  17s. 
  G. 
  M. 
  T., 
  and 
  

   at 
  45m. 
  43s. 
  there 
  was 
  again 
  an 
  increase 
  in 
  the 
  travel 
  of 
  the 
  

   recorder, 
  reaching 
  its 
  maximum 
  at 
  about 
  nh. 
  48m,, 
  the 
  distur- 
  

   bance 
  of 
  the 
  trace 
  ceasing 
  at 
  I2h. 
  9m. 
  The 
  second 
  phase 
  appears 
  

   to 
  be 
  marked 
  by 
  a 
  large 
  increase 
  in 
  the 
  travel 
  of 
  the 
  recorder 
  of 
  the 
  

   E.-W. 
  component 
  at 
  nh. 
  27m., 
  but 
  the 
  trace 
  is 
  not 
  open 
  enough 
  to 
  

   allow 
  this 
  to 
  be 
  decided 
  with 
  certainty. 
  

  

  On 
  this 
  trace 
  it 
  must 
  be 
  noticed 
  that 
  the 
  N-S 
  component 
  is 
  

   about 
  double 
  the 
  E-W 
  in 
  the 
  first 
  phase. 
  There 
  is 
  a 
  maximum 
  at 
  

   about 
  1 
  ih. 
  20m. 
  and 
  another 
  large 
  one 
  at 
  nh. 
  23m. 
  The 
  other 
  

   increase 
  in 
  the 
  travel 
  of 
  the 
  pointer 
  after 
  45m. 
  43s. 
  evidently 
  corre- 
  

   sponds 
  to 
  the 
  large 
  undulations 
  of 
  other 
  records. 
  At 
  Pavia 
  the 
  period 
  

   of 
  these 
  undulations 
  was 
  about 
  30s. 
  ; 
  in 
  the 
  first 
  phase 
  the 
  oscilla- 
  

   tions 
  were 
  very 
  rapid. 
  

  

  Grenoble. 
  — 
  A 
  microseismograph 
  here 
  recorded 
  the 
  earthquake. 
  

   Beyond 
  the 
  fact 
  that 
  the 
  disturbance 
  commenced 
  at 
  nh. 
  28m. 
  26s., 
  

   Paris 
  time, 
  or 
  uh. 
  19m. 
  5s. 
  G. 
  M. 
  T. 
  1 
  , 
  I 
  have 
  no 
  information 
  as 
  to 
  

   either 
  the 
  nature 
  of 
  the 
  instrument 
  or 
  of 
  the 
  remainder 
  of 
  the 
  record. 
  

  

  Strassburg. 
  — 
  Dr. 
  Gerland 
  informs 
  me 
  that 
  his 
  instrument, 
  con- 
  

   sisting 
  of 
  three 
  horizontal 
  pendula 
  set 
  at 
  angles 
  of 
  120 
  with 
  each 
  

   other, 
  was 
  violently 
  affected 
  by 
  the 
  earthquake. 
  The 
  disturbance 
  

   began 
  at 
  nh. 
  18m. 
  32s. 
  G. 
  M. 
  T. 
  without 
  any 
  tremors, 
  with 
  sudden 
  

   and 
  very 
  great 
  oscillations, 
  of 
  14 
  cm. 
  amplitude 
  ; 
  these 
  suddenly 
  

   ceased 
  at 
  I2h. 
  45m., 
  but 
  were 
  succeeded 
  by 
  a 
  very 
  long 
  series 
  of 
  

   diminishing 
  tremor-like 
  oscillations, 
  dying 
  out 
  at 
  14I1. 
  30m. 
  G. 
  M. 
  T. 
  

  

  Potsdam.— 
  A 
  horizontal 
  pendulum, 
  with 
  a 
  boom 
  20cm. 
  long 
  and 
  

   a 
  weight 
  of 
  10 
  grammes, 
  supported 
  by 
  a 
  quartz 
  fibre 
  rising 
  at 
  an 
  

   angle 
  of 
  45 
  , 
  was 
  set 
  in 
  motion 
  at 
  I2h. 
  nm, 
  Potsdam 
  time, 
  which 
  is 
  

  

  1 
  This 
  time 
  was 
  communicated 
  to 
  me 
  by 
  Dr. 
  Friih 
  of 
  Zurich. 
  In 
  Symons' 
  Monthly 
  

   Magazine, 
  XXXII, 
  92 
  (1897) 
  the 
  time 
  is 
  given, 
  in 
  a 
  note 
  by 
  Prof. 
  J. 
  Milne, 
  F.R.S., 
  as 
  

   lih. 
  28m. 
  os. 
  According 
  to 
  Dr. 
  Fruh's 
  communication 
  the 
  time 
  is 
  Paris 
  mean 
  time 
  and 
  requires 
  

   a 
  correction 
  of 
  9 
  m. 
  21s. 
  This 
  also 
  brings 
  the 
  time 
  more 
  into 
  accordance 
  with 
  that 
  recorded 
  

   elsewhere. 
  The 
  time 
  is 
  given 
  as 
  I2h 
  t 
  19m 
  5s. 
  T. 
  E. 
  0., 
  equivalent 
  to 
  1 
  ih. 
  19m. 
  5s. 
  G. 
  M. 
  T. 
  by 
  

   Dr. 
  Agamennone, 
  Boll. 
  Soc. 
  Sismol. 
  Ital, 
  III, 
  pt. 
  ii, 
  292. 
  

  

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  237 
  ) 
  

  

  