WHY are the ribs of coins notched?
Coins used to be valued according to the amount of metal they contained. Fraudsters used to cut the metal off the edges, pocketing the gold and silver. It was incredibly difficult to catch them.
A solution to this problem was suggested by Isaac Newton, who was an employee of the British Royal Mint. He suggested making fine notches on the edges of the coin, which made the worn edges immediately visible.
