How Georgian Britain Built a River in the Sky

Steer a narrowboat across the Pontcysyllte Aqueduct and on one side there's a railing. On the other, there's nothing but six inches of iron and a 126-foot drop to the River Dee. More than two hundred years ago, the engineer William Jessop worried that the men building it would be "giddy and terrified" at the height. They built it anyway, and in November 1805, just weeks after the news of Trafalgar, 8,000 people watched six boats sail across the sky. This is the story of how Georgian Britain built a river in the sky. We follow the Ellesmere Canal from the canal mania of the 1790s to the bold decision to stay high and cross the valley in iron, when no iron canal aqueduct had yet been finished anywhere in the world. You'll meet Thomas Telford, the shepherd's son who called himself the canal's "sole engineer", and William Jessop, the lighthouse foreman's son and pupil of Smeaton, who bore the ultimate responsibility and was almost forgotten. We look at how 18 stone piers were raised from timber walkways, why they're hollow at the top, and how William Hazledine, the ironmaster Telford called "Merlin", built a trough that simply rests on its arches. At the heart of this film are the people who built it. Matthew Davidson, Telford's boyhood friend and a cynical Scottish wit. The masons John Simpson and John Wilson. And the one man who, by Telford's own account, fell during the building of the piers, and whose name nobody recorded. We test the legends of flannel boiled in sugar and mortar made with the blood of 1,700 oxen against the evidence, and we relive the opening day through the words of an eyewitness. Then comes the twist. The canal never reached Chester or Shrewsbury, and in 1944 it was set to be abandoned. It survived because it carried drinking water to Cheshire. Today Pontcysyllte is a UNESCO World Heritage Site and the world's tallest navigable canal aqueduct, and we look at what you can see there, from the towpath to the trough, and why UNESCO's page for it never mentions Jessop. Chisel Marks tells the stories of the great works that built Britain, and of the people whose names history forgot. If you believe they deserve to be remembered, subscribe and switch on notifications, so you don't miss the next film. And if your family came from Cefn Mawr, Froncysyllte or Trevor, or worked at the Plas Kynaston foundry, tell us their name in the comments. Your story could help put a name back on the record. #PontcysyllteAqueduct #ThomasTelford #CanalHistory #WelshHistory #BritishHistory