from  Lightning  at  Purfleet.  2.53 
the  fame  diftance  from  it.  The  remote  end  of  this  long 
wire  hooked  on  occafionally  at  the  end  of  the  brafs  drums, 
which  made  a feparate  cylinder  (the  fourth  part  alluded 
to  above)  about  ten  feet  in  length:  this  was  fufpended 
likewife  by  filk  lines,  and  about  fix  feet  from  the  floor; 
but  in  fuch  a manner,  that  the  fartheft  end  thereof  from 
the  wire  was  within  nine  or  ten  feet  of  the  great 
cylinder. 
The  long  wire  with  the  great  cylinder  and  brafs  drums 
made  the  whole  of  the  fubftitute  for  a thunder-cloud, 
when  they  were  properly  charged. 
The  machine,  employed  to  charge  this  apparatus,  con- 
fifted  at  firfi:  of  two  large  glafs  cylinders  that  were  turned 
by  one  wheel.  But  as  the  fridtion  arifing  from  the  two 
together  rendered  it  difficult  to  work  them,  and  the  ad- 
vantage gained  from  both  in  the  charge  itfelf  was  found 
to  be  not  fo  confiderable  as  might  reafonably  be  expected, 
one  of  them  only  was  made  ufe  of  in  the  following  ex- 
periments. The  place  where  this  machine  charged  the 
great  cylinder,  was  about  ten  or  eleven  feet  from  its 
neareft  end.  It  was  found  expedient  to  be  provided  alfo 
with  another  machine ; but  this  was  employed  only  upon 
particular  occafions,  and  was  generally  placed  at  the  far- 
ther end  of  the  great  cylinder. 
The  floor  of  the  room  being  of  baked  wood,  it  was 
neceflary  to  have  wires  properly  connected  with  the 
K k 2 cufhions 
