Misc: Which european country will lose its independence if there is no heir to the throne?

Questions

Sir Humphrey Davy of London patents the miner's safety lamp.?

William Parson, third Earl of Rosse and maker of large telescopes dies.?

Benito Mussolini (Il Duce) becomes premier of Italy.?

Erich Weiss, better known as Magician Harry Houdini, dies.?

Michael Collins, astronaut (Gemini 10, Apollo 11)?