On this date in history: In 1215, under pressure from rebellious barons, England's King John signed the Magna Carta, a crucial first step toward creating Britain's constitutional monarchy. In 1752, Benjamin Franklin, in a dangerous experiment, demonstrated the relationship between lightning and electricity by flying a kite during a storm in Philadelphia. An iron key suspended from the kite string attracted a lightning bolt. In 1785, two Frenchmen attempting to cross the English Channel in a hot-