When was the Halley's Comet periodicity discovered?

More Questions:

Which country gave birth to the beer Corona?

What sport is the Heisman Trophy awarded in?

How many skittles are used in ‘table skittles’?

London's Trafalgar Square Christmas tree is traditionally given by which country?

According to Thomas Malory, Sir Bedivere's last knightly act is to return what to a lake?

In Greek mythology, who were Hera's parents?

Which country has the longest coastline?

How many pairs of heArts does the common garden worm have?

In 1976, who was the first woman to become a national network news co-anchor?

What was the name of Paul Winchell's dummy?

What WWII general was known as "Old Blood and Guts"?

What did "abolitionists" oppose?

Which two tools are depicted on the former Soviet Union's flag?

What was piloted by Vietnam veteran Stringfellow Hawke?

Which country's wine might be labelled "DOCG"?