In 1770, Parliament passed legislation for improving the navigation of the River Clyde to the city of Glasgow. The act empowered the Magistrates and Town-Council to repair and enlarge the quay on the north side of the river, and build a new one on the south side. The legislation allowed the Glaswegian magistrates to levy a duty on river traffic, to which the Magistrates and Community of Dumbarton claimed exemption based on a 1770 contract between the two burgs.
William Morison, The Decisions of the Court of Session (1811), pg. 14769
Sir David Dalyrymple of Hailes, Decisions of the Lords of Council and Session, from 1766 to 1791 (1826), pg. 446