Describe Franklin's experiment. What did he conclude from his experiment?

Franklin's experiment:

1. Benjamin Franklin took a kite made of silk.
2. At the top corner of the kite, he fixed a metal wire about 30 cm long.
3. The other end of the wire was joined to a string.
4. At the lower end of the string, he tied a metal key and then a silk strip. The silk strip acts as an insulating handle. He flew the kite in thunderstorm.

Observation — He obtained a number of sparks between his knuckle and key when the string got wet.

Conclusion — He concluded that during thunderstorm the clouds acquire an electric charge. Hence, with his kite experiment, he proved that lightning is a form of electricity.