[ asi  ] 
XIV.  An  Account  of  the  Earthquake  which  was  felt  at 
Manchefter  and  other  Places , on  the  i /^th  Day  of  Sep- 
tember, 1777.  In  a Letter  from  Mr.  Thomas  Henry, 
F.  R.  S.  to  William  Watfon,  M.  D.  F.  R.  S. 
I , 
Q T -p  -Manchefter, 
^ October  21,  1777. 
Read  Feb.  19, ' g""' HOUGH  the  fhock  of  an  earthquake 
which  was  felt  on  Sunday  the  1 4th  of 
September,  in  this  and  fome  of  the  neighbouring  coun- 
ties, was  by  no  means  equal  to  thofe  terrible  concuffions 
which  fome  foreign  countries  have  at  times  experienced ; 
yet  as  it  appears  to  have  been  at  leaf!  as  violent  as  any  that 
has  happened  in  this  ifland  for  many  years,  I thought  a 
particular  account  of  it  might  not  be  unaccept  able  to  you, 
efpecially  as  fome  circumftances  attending  it  feem  to  be 
connected  with  a branch  of  natural  philofophy,  for  the 
elucidation  of  which  mankind  are  much  obliged  to  your 
induftrious  and  ingenious  refearches. 
On  the  morning  of  the  day  on  which  the  earthquake 
happened,  I was  confined  to  my  bed  beyond  my  ufual 
hour  by  a head-ach,  with  which  I am  generally  troubled 
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