Rosetta Stone

This replica of the Rosetta Stone is in the National Cryptologic Museum near NSA (National Security Agency) Headquarters at Fort George G. Meade, Maryland. It is a free private museum and is extremely interesting and quite busy. The original Rosetta Stone is in the British Museum. I was surprised at how large it is. Here is a description from Wikipedia: Rosetta Stone.

The Rosetta Stone is 1,123 millimetres (3 ft 8 in) high at its highest point, 757 mm (2 ft 5.8 in) wide, and 284 mm (11 in) thick. It weighs approximately 760 kilograms (1,680 lb). It bears three inscriptions: the top register in Ancient Egyptian hieroglyphs, the second in the Egyptian Demotic script, and the third in Ancient Greek. The front surface is polished and the inscriptions lightly incised on it; the sides of the stone are smoothed, but the back is only roughly worked, presumably because this would have not been visible when it was erected.

I have read about the Rosetta Stone since I was very young and have been interested in breaking codes and old languages. Of course, this interest ended up by getting a Masters Degree in Linguistics and being in the Military Intelligence branch in the Army, but I am still interested. If you don't know about the Rosetta Stone, here is another quote from Wikipedia.

The Rosetta Stone is a granodiorite stele, found in 1799, inscribed with three versions of a decree issued at Memphis, Egypt in 196 BC during the Ptolemaic dynasty on behalf of King Ptolemy V. The top and middle texts are in Ancient Egyptian using hieroglyphic script and Demotic script, respectively, while the bottom is in Ancient Greek. As the decree has only minor differences between the three versions, the Rosetta Stone proved to be the key to deciphering Egyptian hieroglyphs.

Oh, the Museum had a first edition copy of Jean-François Champollion's book about the decipherment of Egyptian Hieroglyphics. 

CHAMPOLLION, Jean François, Jacques Joseph CHAMPOLLION-FIGEAC, and Olivier Charles Camille Emmanuel de ROUGÉ. 1844. Monuments de l'Égypte et de la Nubie. Notices descriptives conformes aux manuscrits autographes rédigés sur les lieux par Champollion le jeune. [tom. 1 edited by J.J. Champollion-Figeac; tom. 2 by Viscount O.C.C.E. de Rougé.].