from  Lightning  at  Purfieet.  303 
fo  near  to  the  drums  as  frequently  to  touch  the  metal. 
In  this  lituation,  a fmall  faint  luminous  ftream  was  ob- 
ferved  between  the  top  of  the  cartridge  arid  the  metal 
drum. 
Sometimes  this  ftream  would  fet  fire  to  the  gun-pow- 
der at  the  inftant  of  the  application ; at  others,  it  would 
require  half  a minute  or  more  before  it  took  effeCh  But 
this  difference  in  time  might  probably  arife  from  fome 
difference  in  the  circumftances,  for  any  the  leaft  moifture 
in  the  filk  lines,  the  powder,  or  in  the  paper  itfelf,  was 
unfavourable  to  the  experiment. 
This  new  method  of  firing  gun-powrder  by  a luminous 
ftream  of  the  matter  of  lightning  {urely  merits  the  moft 
ferious  attention;  and  more  efpecially  in  thofe  cafes 
where  pointed  conductors  are  fixed  to  fecure  magazines 
of  gun-powder  from  fuch  accidents. 
In  repeating  the  laft  experiment,  there  were  one  or 
two  inftances  where  the  powder  was  fired  without 
making  ufe  of  the  long  wire ; but  never  with  the  great 
cylinder  alone:  for  we  were  obliged  to  connedt  it  with 
the  brafs  drums  by  means  of  a wire  ten  or  twelve  feet 
long.  v 
It  was,  however,  a confiderable  time  (ten  minutes  or 
more)  before  the  experiment  fucceeded  even  with  this 
laft  apparatus.  This  was  not  the  cafe  with  tinder;  for  it 
fired 
