Roger Pearse is currently blogging (1, 2) on the origin of the story that Caliph Omar ordered the destruction of the library of Alexandria. There are several other stories: the library was destroyed when Julius Caesar captured the city, it vanished in the 365 earthquake, Aurelian‘s soldiers are responsible, Christian agitators set it afire.
But perhaps it is not necessary to look for such an event.
There are several reports about the number of scrolls in the library. 400,000 is one of the lower estimates. Now a papyrus scroll is vulnerable and a book needed to be copied after a century. This means that every year, about 4,000 scrolls had to be copied. If we assume that one scroll took one month, we need about 300 to 350 writers, excluding the correctors, illustrators, the people who prepared ink and papyrus, and so on. All these people were highly paid professionals.
These numbers are all guesswork, but they serve to illustrate a point: the library was too big to survive. Even if Caesar and Aurelian hadn’t attacked the city, even if there had been no earthquake, even if there had been no interventions by Christian and Muslim fanatics, the library would have vanished.
Excellent point. Reminds me of this poet:
“But they didn’t fill/the desert with pyramids./They just built some. Some./They’re not still out there,/ building them now. Everyone,/everywhere, gets up and goes home.”
In fairness, more on her can be found here.
That’s the reason usually given for the lost centuries of India and South East Asia: books (in our case written on palm leaf) have to be recopied every generation; if there is any sort of political or economic disruption, they are not copied and — absolutely all is lost. Funny, it never occurred to western scholars re Alexandria — one more consequence of living a sheltered life? : )
Please read this short article by Roger Bagnall arguing (lucidly, in my opinion) that the lower estimates are still one order of magnitude too high.
As for library’s destruction, the article resonates well with your posting: “An unburned building full of decaying books would not have made a particle’s worth of difference.”