Virtually every known verse written in the seventh century B.C. by the lyric poet Sappho, to cite the most prominent example, derives from fragments of her work recovered at Oxyrhynchus; according to one Oxford papyrologist working on the trove today -- only 5 percent of the fragments have been translated over the past century -- the woman's erotic verses were considered too scandalous by medieval monks to copy, and would have been lost entirely if not for the scrap heap of Oxyrhynchus.
Oxyrhynchus was an ancient Egyptian town long lost to the desert. It was rediscovered late in the 19th century when farmers harvesting soil from the site "came across fragments of papyri," some of which were then offered for sale "in the street bazaars of Cairo." Oxford scholars organized a dig. Twenty years of effort returned to Britain "fifty thousand papyrus fragments from the sandy pits, many of them lying thirty feet below the surface."
Most of the fragments are pretty tedious, I'm sure. Tax records, intergovernmental communications. Mustn't those working to translate the scraps try to keep awake by looking for things of more interest, like a poem, say? Maybe there's not another line of the old girl left to find, but I like to imagine it. Sappho's a favorite of mine; I'd be happy to hear another few lines have been rescued from the abyss.
In his A Splendor of Letters Nicholas Basbanes describes the fortuitous recovery of many ancient texts that otherwise were allowed to go out of print by those who copied and kept available what in their era was considered worth reading. Rubbish heaps are a good source, it seems. Which actually makes encouraging the reports that landfills are so anoxic that items tossed into them don't break down. I mean, the archaeologists of the next millennium may find Fresh Kills a more fruitful archive than anything we've made real efforts to preserve.
source: A Splendor of Letters: the permanence of books in an impermanent world by Nicholas A. Basbanes