from  Lightning  at  Purfleet.  279 
rounded  end  the  fpark  at  the  cramps  appeared  confidera- 
bly  lefs  to  every  obferver. 
exp.  xxv.  Upon  repeating  the  twenty-firft  experi- 
ment where  the  two  fubftitutes  were  brought  into  con- 
ta<51,  every  other  circumftance  remaining  the  fame,  the 
rounded  end  was  ft  ruck  at  the  fame  diftance  nearly  as 
when  a fpark  was  taken  by  a larger  metal  ball  (fuppofe 
three  inches  in  diameter)  from  any  part  of  the  great 
cylinder  when  equally  charged : for  in  this  cafe  the  two 
fubftitutes,  being  in  contadl,  made  in  reality  but  one 
great  fubliitute. 
exp.  xxvi.  I now  repeated  the  twenty-fecond  experi- 
ment, where  motion  was  introduced;  and  without  any 
other- change  of  circumftances  than  putting  in  the  place 
of  the  point  the  rounded  end.  Upon  this  occafion,  as 
well  as  upon  the  former,  the  fame  perfon  moved  the 
ftand  with  the  rounded  end  upon  it,  and  with  the  fame 
velocity  (as  near  as  he  and  others  prefent  could  judge)  but 
not  before  the  connedled  fubftitutes  were  fully  charged 
by  an  equal  number  of  turns.  The  inftant  that  the 
rounded  end  approached  within  a.  certain  diftance  of  the 
ball  at  the  end  of  the  lefs  fubftitute,  it  ftruck ; but  the 
explofion  feemed  inferior  to  that  which  the  point  occa- 
fioned  at  the  diftance  of  nine  inches  and  an  half.  In  this 
experiment  the  diftance  between  the  rounded  end  and 
Ifel'HHHil  baft 
