1856 British Guiana One-Cent Magenta photograph using an infrared filter
Infrared photographs taken at the Smithsonian National Postal Museum in 2014 revealed a four-leaf clover beneath the seventeen-point star.
Photo courtesy Smithsonian’s National Postal Museum
1856 British Guiana One-Cent Magenta photograph using an infrared filter
Infrared photographs taken at the Smithsonian National Postal Museum in 2014 revealed a four-leaf clover beneath the seventeen-point star.
(Photo courtesy Smithsonian’s National Postal Museum)
