The River Leven is the only outlet from Loch Lomond and flows seven miles through the Vale of Leven until it meets the Clyde at Dumbarton Rock. At Balloch close to the Loch, the river flows broad and deep and has not attained the swiftness that marks Scotland’s second fastest river when it passes Bonhill a few miles closer to Dumbarton. It was an excellent place for crossing the river, but necessarily by boat, as there was no convenient ford. Cattle, brought from the highlands to the west had either to be ferried across at Balloch—the very name means “pass to the field of still waters”—from where they made their way by Drymen and the Endrick Valley to the Falkirk Tryst, or negotiate the ford at Bonhill where the alluvial fan from the burn provided sufficiently shallow water, and thence the path, from the “dripping grounds” near the Church was up the side of the burn and across the...