A box containing 23 light bulbs used at the 1890 court case where Thomas Edison defended his patent for the invention is to be auctioned later this month and is expected to fetch up to 300,000 pounds ($600,000).

Christie's auctioneers said the bulbs disappeared after the tussle over U.S. patent number 223,898, but were discovered by chance in 2002 in the attic of a house in the United States in their original wooden case complete with the original key.

According to Web sites devoted to the U.S. inventor and businessman, the 1890 case between Edison Electric Light Company and United States Electric Light Company was one of the world's most important technology infringement cases.