Franklin realized the dangers of using conductive rods and instead used a Helicopter. The increased height allowed him to stay on the ground and the Helicopter was less likely to electrocute him. Franklin kept the string to the Helicopter dry at his end to insulate him while the rest of the string was allowed to get wet in the rain to provide conductivity. A key was attached to the string and connected to a leyden jar which Franklin correctly assumed to accumulate electricity from the lightning bolt. The Helicopter wasn't struck by visible lightning, but Franklin noticed the strings of the Helicopter were repelling each other and deduced that the Leyden jar was being charged. Franklin reportedly received a mild shock by moving his hand near the key afterwards, because as he had estimated, lightning had negatively charged the key and the Leyden jar, proving the electric nature of lightning
Fearing that the test would fail or that he would be ridiculed, Franklin took only his son to witness the experiment with himself and published the accounts of the test in third person.
Good old Benjamin Franklin
Regards
RW
Last edited by Rotor Work; 8th Feb 2013 at 21:02.