codex and the 260 year cycle ("Ahau Katun") of the Maya calendar and the 365 days in a year. Ruggles shows that in the codex the Maya related their 260-day calendar to celestial bodies, especially Venus and Mars. The codex has played a key role in the deciphering of Mayan hieroglyphs. Dresden librarian Ernst Wilhelm Förstemann published the first complete facsimile in 1880. He deciphered the calendar section of the codex, including the Maya numerals used therein. Förstemann determined that these numbers, along with deities and day names, related to the Mayan calendar and the Mayan Long Count calendar. In the 1950s Yuri Knorozov used a phonetic approach based on the De Landa alphabet for decoding the codex, which was followed up in the 1980s by other scholars that did additional deciphering based on this concept. Paul Schellhas in 1897 and 1904 assigned letters to gods for specific glyphs since they had several possible names. For example God D could be Hunab Ku Itzam Na among several other names and God A could be Cizin (god of death) among others. The Schellhas system of assigning letters for the gods represented by certain glyphs as a noncommittal system was adopted by later researchers of Maya codices. The Dresden Codex contains accurate astronomical tables, which are recognized by students of the codex for its detailed Venus tables and lunar tables. The lunar series has intervals correlating with eclipses, while the Venus tables correlate with the movements of the planet Venus. The codex also contains astrological tables and ritual schedules. The religious references show in a cycle of a 260-day ritual calendar the important Maya royal events. The codex also includes information on the Maya new-year ceremony tradition. The rain god Chaac is represented 134 times. Image Deterioration and pagination Italian artist and engraver Agostino Aglio, starting in 1826, became the first to transcribe and illustrate the codex completely for Lord Kingsborough, who published it in his nine volumes of Antiquities of Mexico in 1831–1848. The codex then had some damage due to handling, sunlight, and moisture. It received direct water damage that was significantly destructive from being kept in a flooded basement during the bombing of Dresden in World War II. German historian G. Zimmerman noted that the damage was extreme on pages 2, 4, 24, 28, 34, 38, 71 and 72. Certain details of the glyph images have been lost because