The Inventor of the Lightning Rod


An examination of the Benjamin Franklin Lightning Rod   System erected upon the Warner House at Portsmouth, N.  H., over 150 years ago showed that very high point rods were used, and that the rods extended into the earth from 6 to 10 feet.   Further information regarding   the Benjamin Franklin System is contained in Technologic Papers No. 56- of the United States Bureau of Standards, from which we quote-

"In the summer of  1753 he  erected on  his  house  in  Philadelphia the  only  lightning rod  then  in  existence.   This  rod,  which  was  of iron, extended 5 feet into the  ground and  had  sharp points raised 7 to  8 feet above  the  roof, which  was  evidently intended by  its  inventor to  serve both  as  a  protection against lightning, and  as  a  means  of  observing the  effects of  atmospheric electricity.   Franklin's  confidence in  the   protective properties of  his lightning rod  was  such  that he  persuaded several  of  his  friends to  allow  him  to  erect similar rods   on  their houses   in  order   that he  might  have   a  better opportunity to  observe their  effects.   After  many   months of  patient waiting his  confidence  in  his  new  device  was  found to  be  justified.  During a  severe  thunder  storm  several  persons plainly  saw   lightning  strike  a rod  on  the   house   of  a  Mr. West.   The  flash  was  carried  off  without  damage  to  the building and   the  only  observable  evidence of  its  passage was  a  slight melting of  the iron  at the  point  and  a  disturbance of  the  earth about the  place  where it entered the ground, which  was  afterward found to  be very dry."