from  Lightning  at  Purfleet.  299 
fharp  (as  it  was  expreffed)  and  violent,  but  not  quite  fo 
difagreeable  as  when  the  great  cylinder  was  connected 
with  it,  and  fimilarly  charged. 
exp.  xlvii.  Having  procured  an  equal  quantity  of 
the  fame  kind  of  wire,  and  of  the  fame  diameter,  with 
that  which  was  fufpended  and  tried  in  the  laft  experi- 
ment, it  was  placed  in  the  form  of  coils  upon  a board, 
fixed  on  the  top  of  a long  ftand  of  glafs,  without  having 
any  connection  whatfoever  with  the  great  apparatus,  or 
any  part  of  it.  Thefe  coils  were  then  fully  charged  by 
the  power  of  one  of  thofe  machines  only.  _ The  fenfa- 
tion  they  afforded,  in  confequence  of  caufing  fparks, 
was  very  inconfiderable,  compared  with  what  had  been 
obferved  in  the  laft  experiment. 
exp.  xlviii.  The  feveral  coils  of  wire  employed  in 
the  laft  experiment,  as  likewife  feven  hundred  yards 
more  in  coils  alfo,  were  joined  together  at  their  feveral 
ends.  Thefe  coils  being  then  ftrung  upon  filk  lines,  were 
drawn  out  into  a form  refembling  that  of  a fcrew,  and  fe- 
parated  from  each  other  in  fuch  a manner  all  along  as 
to  occupy  one  hundred  yards  of  filk  line.  The  feveral 
diameters  of  thefe  coils,  at  a mean,  were  about  fifteen 
inches.  As  I had  fo  fhort  a time  in  which  to  prepare 
and  fufpend  them  properly,  the  difadvantage  of  their 
touching  and  interfering  each  other  in  many  places 
Vol.  LXVIII.  Q q could 
