Did the Chinese discover America?

The BBCNews website posted an article today about a Chinese map that, if authentic, may suggest that Chinese mariners visited and mapped the coasts of America before Columbus. Chinese characters on the map apparently say that it was drawn in 1763 as a copy of a map made in 1418. The map’s ink and paper are being tested to try to confirm the 1763 date, but the article notes that there is a great deal of skepticism regarding the map’s authenticity. Even if it can be traced to the eighteenth century, the only evidence for the original 1418 comes from the notation on the map itself.
Via Digg.com