CANTON The great South China port of Canton has become once again the country's principal exporter. In the nineteenth century, Canton was the port of entry for most Western traders, including those from the United States. But in recent times, Canton languished until it received a new impetus to foreign trade in the late 1970s. For the first half of this year, exports from Canton Province rose by 46.7 per cent, to $1.8 billion (in the rest of the People's Republic, by contrast, ...