Expert leggers Daniel Jinks and Ernest Wood. The two men demonstrate the process of 'legging' through Barnton Tunnel on the Trent and Mersey Canal. Early canal tunnels had no tow-paths, so to propel the boat through the tunnel two people had to lay on their backs on the boat, and push the boat along using their feet on wall of the tunnel. The Barnton Tunnel was over 500 yards long.