THEY are two rival cities who have slugged out for centuries. When it comes to Edinburgh and Glasgow, the cities seem to see everything as a source of competition: salt and sauce versus salt and vinegar, high culture versus clubbing; and even trams versus the subway. But for the University rowing teams gathered outside Glasgow s Riverside Transport Museum yesterday on a windy Saturday, the rivalry was about one thing only: who can win the Scottish Boat Race. The Edinburgh-Glasgow race - one of the oldest University boat races in the world - held its 139th meet on a choppy River Clyde, with University teams from the two cities pitched against each other across eight races.