 The contractors were William Gibb (founder of the engineering dynasty that led to Sir Alexander Gibb & Partners) and John Muir, who also built the nearby Maryhill locks.A foundation stone was laid on 16 June 1787 by Archibald Spiers, the chairman of the canal committee.When opened in 1790 it was Britain's largest aqueduct, and onlookers were impressed at the sight of sailing boats crossing above them.