[Dingfod]

Also on May 20th:

1506
Chistopher Columbus died in Valladolid, Spain.

1747
British ship surgeon, James Lind, on the HMS Salisbury discovered by experimentation the cure for scurvy, lemons and oranges (vitamin C).

1830
D. Hyde of Reading, Pennsylvania patented the fountain pen. It was 1884 before the first practical fountain pen went on the market.

1862
President Abraham Lincoln signed The Homestead Act, opening up vast tracts of land in the west to settlement.

1873
Jacob Davis and Levi Strauss received a patent for their copper riveted denim jeans.

1916
The first Normal Rockwell painting appeared on the cover of The Saturday Evening Post magazine.

1956
The first hydrogen bomb dropped from an airplane was exploded over Bikini Atoll in the South Pacific.

1964
The first nuclear powered lighthouse went into operation in the Chesapeake Bay, at Baltimore harbor, Maryland, powered by a 60 Watt generator.