Evan Andrews puts the list together, starting with Stradivari violins:
One lost technology of the 1700s is the process through which the famed Stradivari violins and other stringed instruments were built. The violins, along with assorted violas, cellos, and guitars, were constructed by the Stradivari family in Italy from roughly 1650-1750. The violins were prized in their day, but they’ve since become world famous for having an unparalleled—and impossible to reproduce—sound quality. Today there are only around 600 of the instruments left, and most are worth several hundred thousand dollars. In fact, the name Stradivari has become so synonymous with quality that it has come to serve as a descriptive term for anything considered to be the best in its field.You can read the rest of the list here. To my mind the Library of Alexandria was the greatest loss to humanity but the above reminded me of an article I read in my school paper at Texas A&M University in the mid-90's. A professor there had claimed that he had discovered the secret of reproducing the Stradivarius through the use of chemicals. Last year he was finally vindicated:
How was it Lost?
The technique for building Stradivari instruments was a family secret known only by patriarch Antonio Stradivari and his sons, Omobono and Francesco. Once they died, the process died with them, but this hasn’t stopped some from trying to reproduce it. Researchers have studied everything from fungi in the wood that was used to the unique shaping of the bodies in order to describe the famous resonance achieved by the Stradivarius collection. The leading hypothesis seems to be that the density of the particular wood used accounts for the sound. Still, some dispute the claim that the instruments are special at all. In fact, at least one study concluded that most people don’t even notice a difference in sound quality between a Stradivari violin and a modern counterpart.
For centuries, violin makers have tried and failed to reproduce the pristine sound of Stradivarius and Guarneri violins, but after 33 years of work put into the project, a Texas A&M University professor is confident the veil of mystery has now been lifted. Joseph Nagyvary, a professor emeritus of biochemistry, first theorized in 1976 that chemicals used on the instruments – not merely the wood and the construction – are responsible for the distinctive sound of these violins. His controversial theory has now received definitive experimental support through collaboration with Renald Guillemette, director of the electron microprobe laboratory in the Department of Geology and Geophysics, and Clifford Spiegelman, professor of statistics, both Texas A&M faculty members. Their work has been published in the current issue of the scientific journal Public Library of Science ONE (PloSONE).I can't imagine the satisfaction he must have felt after so many years of being dismissed by experts and colleagues. I guess that shortens Andrews' list to nine.