Benjamin Franklin (1706-1790), American scientist, inventor and statesman. Franklin showed that lightning is electricity by flying a kite carrying a metal key during a thunderstorm. This led to his invention of the lightning rod to protect buildings from lightning strikes. He also invented fins for swimming, bifocal glasses, a urinary catheter and showed that evaporation cooled objects. In between all this, he also found time to found the USA, help shape the revolution and be a signatory of the Declaration of Independence.