Q: Did they originally throw a real hammer?

A: Yes. In fact, they originally threw a sledge hammer. The event has its routes in the Tailteann Games, but was popularized by the Scottish Highland Games. The implement used during this event resembled the "modern" hammer (to me, it looks like a shotput on the end of a handle). However, the hammers used during these games could be any weight, and the handles could be any length (although they were generally between 3 to 3.5 feet long). The English standardized the weight (16lbs) and handle length (3.5ft) at the end of the 19th century, and required the hammer to be tossed from within the confines of a circle measuring 7ft in diameter.