from  Lightning  at  Purfleet.  315 
each  of  the  metal  doors  in  the  middle  of  the  fides; 
which  latter  fhould  be  bent,  fo  as  to  avoid  the  doors,  in 
the  fame  manner  as  thofe  which  are  already  placed  upon 
the  outward  fide  of  the  outermoft  magazines.  All  which 
rods  fhould  be  continued  into  the  earth,  and  be  made  to 
communicate  with  the  bottom  of  the  water  of  the  nearefl 
wells,  by  means  of  leaden  pipes,  clofely  connected  with 
thefe  iron  rods.  Likewife,  that  ftrips  of  lead  be  put 
upon  the  copeing  of  the  end  walls,  and  be  made  to  com- 
municate with  the  rods  to  be  placed  at  the  feveral  cor- 
ners as  above  directed. 
3.  But  that  the  greateft  degree  of  fecurity  would  be 
attained  by  covering  the  whole  roof,  and  the  tops  of  the 
end  walls  of  each  of  the  five  magazines,  with  lead; 
erecting  all  the  additional  conducing  rods  above  di- 
rected; and  forming  a communication  between  the 
leaden  covering  of  the  roof,  and  the  bottom  of  the  wells 
as  before  mentioned. 
As  to  the  other  buildings  belonging  to  the  magazines 
we  recommend : 
1 . That  a pointed  rod,  fimilar  to  the  reft,  be  erected  at 
each  end  of  the  proof-houfe,  and  be  united  with  the  lead 
already  there : alfo,  that  the  lead  on  the  roofs  of  the  two 
low  buildings,  deftined  for  the  reception  of  the  empty 
powder  calks,  &c.  be  connected  with  the  wells  by  means 
Vol.  LXVIII.  S f of 
