BEIJING, China -- The world's largest nonfiction work and its earliest encyclopedia is going to be given a new lease of life when it gets reprinted for the first time in 600 years.

The Yongle encyclopedia (Yongle Dadian) -- made up of 22,877 volumes in 11,095 books -- is being republished by the Beijing Library Press, China's state-run Xinhua news agency said on Thursday.

The move came as experts from China and around the world gathered in Beijing to attend a global meet to mark the 600th anniversary of the compilation.

There they talked about ways of preserving and publishing the "cultural treasure," which is 12 times the size of the encyclopedia put together by the French author Diderot in the 18th century, and which experts predict hit the scales at 40 tons.

In modern times, the Spanish encyclopedia "La Enciclopedia" "Univeral Ilustada Europeo-Americana" has 105,000 pages. The longest modern work of fiction is the 40-volume novel "To-kugawa leyasu" by Sohachi Yamaoka.

When speaking of long books, we typically refer to printed works or works created on paper. There are many other types of ancient books such as the 15,000 clay tablets left by the ancient Hittites.

Early writing and reading was handled in many different ways. Some writing was written and read left to right, some right to left, some top to bottom, and some back and forth, alternating from line to line. In the sixth century B.C. most Mediterranean cultures agreed to use left-to-right reading and writing. However, the Hebrews kept their right-to-left writing.

The library of Alexandria was designed to hold all the books that existed in the world at the time (295 BC) and contained 700,000 volumes. It was damaged by fire during a siege by Julius Caesar in A.D. 47. Civil wars later inflicted more damage and by AD 400 nothing remained of the once great library.

Some experts believe that the first books were created by the Sumerians over 5,000 years ago. The Sumerians had a cuneiform alphabet with letters made up from a triangular symbol. The symbol could be made with the point facing up, down, left, or right. Combinations of the various symbol positions formed specific letters. A wedge-shaped tool was pressed into clay tablets to form the letters. The tablets were then dried or fired so they would last. Some of these "books" even had clay envelopes.

Before the introduction of the printing press, books were made of vellum (calf or lambskin) because it was extremely durable. In William Randolph Hearst's castle at San Simeon, California, there are lampshades made from fifteenth-century vellum prayer books. Even today the vellum is in excellent condition.