for, without their co-operation, there was the implicit threat that a competing canal would be built to the Trent. The major opposition came from the water-powered mill owners along the Derwent, of which there were many, downstream of the proposed canal, fearful of loss of flow in dry weather. Since, between Cromford and Pinxton, the canal would be level, Jessop was able to give reassurance, carefully downplaying the problem of the descent, with its locks, to Langley Mill. However, with the assistance of Benjamin Outram, he also spent over a year measuring the flow rate of the Derwent, a precaution which was invaluable when the bill was placed before Parliament. He also proposed to make the summit pound deep enough that it could be replenished on Sundays when the mills were closed, and hold enough water to supply the locks for a week even in the driest weather. The length from the Erewash Canal would be built to match, accessible to barges from the Trent. Through the Butterley Tunnel and along the narrow Derwent valley it would be to narrow boat standards, similar to the Trent and Mersey. At the last minute before the Bill was to be presented to Parliament, Richard Arkwright raised a problem. The assumption had been that water would come from Cromford Sough, the drainage from the Wirksworth lead mines. Arkwright complained that the canal crossed his land and insisted that water should be obtained from the river by raising the height of the weir at Masson Mill. This was an unwelcome complication (which would mainly benefit Arkwright himself and his mill) but the canal Committee reluctantly agreed. Construction The canal obtained its Act of Parliament in 1789. Perhaps because they had quoted too little, basing their estimates on Jessop's cost predictions which may themselves have been too optimistic, the contractors soon found themselves in financial difficulties and, at the end of 1790, simply walked off the site. Benjamin Outram hastily took over full management control and was awarded a salary increase. In January 1792 there was a problem when the Amber Aqueduct failed but, by May, the canal to the east of Butterley was virtually complete and most of the earthworks to the west. The Butterley Tunnel was excavated by first sinking 33 shafts, about apart as much as deep to give a number of working faces. Most of the heading was through soil, with