"By Smeaton's advice, the first Act of Parliament (1759) was applied for, whose preamble runs:-' Whereas the river Clyde from Dumbreck to the Bridge of Glasgow is so very shallow in several parts thereof that boats, lighters, barges, or other vessels cannot pass to or from the City of Glasgow except it be in the time of flood or high-water at spring-tides; and if the same was cleansed and deepened," . . . . .