•raBo  Papers  relative  to  an  Accident 
ball  was  not  more  than  fix  inches  and  an  half.  From  which 
it  appears,  that  even  in  thofe  circumftances  the  point  was 
ftruck  at  a greater  diftance  than  the  rounded  end  in  the 
proportion  of  nine  and  an  half  to  fix  and  an  half. 
exp.  xxvn.  It  has  been  obferved  in  a former  part  of 
this  paper,  that  a great  quantity  of  rain  fell  when  the 
accident  happened  at  Purfleet;  as  this  circumftance 
feemed  to  be  material,  it  was  proper  to  put  the  model 
into  a fimilar  fituation  ; and  therefore,  after  removing  the 
tin-foil  upon  the  parapet,  I wafhed  the  model  all  over 
with  a fponge;  and,  whilft  it  continued  in  this  ftate,  the 
machine  was  put  into  motion:  after  ten  turns  of  the 
wheel,  the  point  was  ftruck  at  five  inches  diftance.  In 
confequence  of  this,  a fmall  explofion  (more  vivid 
than  in  the  feventeenth  experiment)  appeared,  not  only 
♦ 
between  the  cramps ; but  alfo  another  was  feen,  ftill  more 
vivid,  at  the  inner  corner  of  the  parapet,  neareft  to  the 
cramps,  darting,  as  it  feemed,  from  the  gutter  up  to  the 
cramps. 
exp.  xxvili.  Upon  pafting  tin-foil  upon  the  top  of 
the  parapet  quite  round  the  model,  as  had  been  done 
before,  and  moiftening  the  inner  part  of  the  parapet 
down  to  the  gutter,  the  ftroke  was  again  received  by  the 
point,  when  the  fame  appearances  were  obferved  as  in 
the  laft  experiment. 
I 
EXP. 
