On  the  Influence  of  Gas-  and  JVater-Pipes  on  Lightning.     115 
with  every  thing  up  to  that  time  existing,  is  clear  e.g.  from  this, 
that  Tait,  in  his  work  (p.  Ill),  when  speaking  of  the  memoir 
above  mentioned,  in  which  I  amplified  the  considerations,  says  : — 
"  Clausius  has  adopted  an  extremely  different  mode  of  attacking 
questions  as  to  the  effect  produced  by  heat  upon  a  substance." 
Xn  .  On  the  Influence  of  Gas-  and  JVater-pipes  in  determining  the 
Direction  of  a  Discharge  of  Lightning.  By  Henry  Wilde, 
Esq.* 
ALTHOUGH  the  invention  of  the  lightning-conductor  is  one 
of  the  noblest  applications  of  science  to  the  wants  of  man, 
and  its  utility  has  been  established  in  all  parts  of  the  world  by 
the  experience  of  more  than  a  century,  yet  a  sufficient  number 
of  instances  are  recorded  of  damage  done  by  lightning  to  build- 
ings armed  with  conductors  to  produce  in  the  minds  of  some  an 
impression  that  the  protective  influence  of  lightning-conductors 
is  of  but  questionable  value. 
The  destruction,  by  fire,  of  the  beautiful  church  at  Crumpsall, 
near  Manchester,  during  a  thunderstorm  on  the  morning  of  the 
4th  instant,  has  induced  me  to  bring  before  the  Society,  with  a 
view  to  their  being  known  as  widely  as  possible,  some  facts  con- 
nected with  the  electric  discharge  which  have  guided  me  for 
some  years  in  the  recommendation  of  means  by  which  disasters 
of  this  kind  may  be  averted. 
For  the  proper  consideration  of  this  subject,  it  is  necessary  to 
make  a  distinction  between  the  mechanical  damage  which  is  the 
direct  effect  of  the  lightning  stroke,  and  the  damage  caused  in- 
directly by  the  firing  of  inflammable  materials  which  happen  to 
be  in  the  line  of  discharge. 
Instances  of  mechanical  injury  to  buildings  not  provided  with 
conductors  are  still  sufficiently  numerous  to  illustrate  the  terrific 
force  of  the  lightning  stroke,  and  at  the  same  time  the  ignorance 
and  indifference  which  prevail  in  some  quarters  with  respect  to 
the  means  of  averting  such  disasters ;  for  wherever  lofty  build- 
ings are  furnished  with  conductors  from  the  summit  to  the  base 
and  thence  into  the  earth,  damage  of  the  mechanical  kind  is  now 
happily  unknown. 
Even  in  those  cases  where  lightning-conductors  have  not  ex- 
tended continuously  through  the  whole  height  of  a  building,  or 
where  the  lower  extremity  of  the  conductor  has,  from  any  cause, 
terminated  abruptly  at  the  base  of  the  building,  the  severity  of 
the  stroke  has  been  greatly  mitigated,  the  damage  being  limited 
in  many  cases  to  the  loosening  of  a  few  stones  or  bricks. 
*  From  the  Proceedings  of  the  Literary  and  Philosophical  Society  of 
Manchester,  Januarv  9,  1872.     Communicated  bv  the  Author. 
12 
