Tay, the largest river of Scotland, pours into the German Ocean a greater bulk of water than any other river of Great Britain. The Dochart is the chief feeder of Loch Tay, and from this lake the Tay flows past Dunkeld and Perth, at the mouth of the Earn widening into the Firth of Tay, from three fourths of a mile to a mile wide, and falling into the North Sea about ten miles below Dundee, after a course of 120 miles. It is navigable to Perth, and the tide flows a mile further up. The salmon-fisheries are valuable.