FRANKLIN’S EXPERIMENT: Franklin flew a kite made of silk in a thunder-storm. At the top comer of the kite, he fixed a metal wire about 30 cm long. The other end of the wire was joined to the string. At the lower end of the string, he tied a metal key.
When the string got wet, he obtained a number of sparks between his Knuckle and the key.
He concluded from his experiment that in a thunderstorm, the clouds acquire an electric charge due to friction.