Cartier Paris crafted this sophisticated copper and brass decorative box in the 1950s. It is a puzzle box that uses Leonardo da Vinci's specular writing technique*. If you look at the box the straight way, the text engraved on the top is incomprehensible. Placing the lidded box in front of a mirror allows the hidden message to be deciphered. This secret message is an invitation to a socialite wedding in New York in 1959!
The message reads:
"Mr. and Mrs. Frank L. Bernstein have the honor of announcing the marriage of their daughter Joan Honey to Mr. Frederic Sanford Berman on Sunday the nineteenth of April nineteen hundred and fifty-nine New York."
The box is lined on the inside with wood and has an engraved Cartier underside.
This is a unique historical memorabilia and a rare collectible Cartier piece.
 
Note: * Specular writing or mirror writing is formed by writing in the direction that is the reverse of the natural way for a given language, such that the result is the mirror image of regular writing: it appears normal when reflected in a mirror. It is sometimes used as an archaic form of cipher. Some people can produce handwritten mirrored text. Notably, Leonardo da Vinci wrote most of his notes in this way. Mirror writing calligraphy was popular in the Ottoman Empire, where it often carried mystical associations.
(credit: Wikipedia).