An unexpected discovery awaited a team of Israeli archaeologists in a drainage canal dating from roughly 2,000 years ago: an aluminum bottlecap. From a beer bottle. No, the good people of ancient Sussita weren't producing aluminum metal. The meaning of the startling discovery is that millennia after its construction, the drainage canal was still working, centuries after the city's final destruction by earthquake. Made of aluminum and feather-light, the bottle-cap floated on rainwater that washed into the canal, says Dr. Michael Eisenberg, head of an Israeli archaeological team digging the site. This canal, or less romantically -- a sewer, passed...